JP5226571B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus that records an image on a recording medium by light irradiation.

  A diffraction grating capable of changing the depth of a diffraction grating by alternately forming fixed ribbons and flexible ribbons on a substrate using semiconductor device manufacturing technology and bending the flexible ribbons relative to the fixed ribbons. Types of light modulation elements have been developed. In such a diffraction grating, the intensity of specularly reflected light or diffracted light changes by changing the depth of the groove, so that it has been proposed to be used in an image recording apparatus that records an image on various recording media.

  For example, the image recording apparatus is provided with a plurality of diffraction grating type light modulation elements and irradiated with light, and the reflected light from the light modulation element in a state where the fixed ribbon and the flexible ribbon are located at the same height from the reference plane ( (0th order light) is guided to the recording medium, and non-zero order diffracted light (mainly first order diffracted light) from the light modulation element in a state where the flexible ribbon is bent is shielded, thereby realizing image recording on the recording medium. The

  In Patent Document 1, in such an image recording apparatus, by correcting the timing at which the light modulation element transitions between ON and OFF, the light modulation element transitions from the OFF state to the ON state, and from the ON state to the OFF state. Corrects misalignment in the drawing area caused by asymmetry when changing to the state, differences in characteristics of each photosensitive material, and differences in the length and position of the irradiation area in the scanning direction of each light modulation element Techniques to do this are disclosed.

JP 2004-4525 A

  By the way, in the image recording apparatus, each light modulation is performed while moving a plurality of irradiation areas on the recording medium irradiated with light from a plurality of light modulation elements of the light modulator in a scanning direction intersecting the arrangement of the irradiation areas. Although the elements are controlled, depending on the accuracy of mechanical adjustment such as the accuracy of mounting the optical modulator in the image recording apparatus, the positions in the scanning direction of the plurality of irradiation areas are greatly different, and the image is recorded with high accuracy. The problem of being unable to do so may arise.

  In this case, even if the method of Patent Document 1 is adopted, in this method, by selecting one clock from a clock group that is sequentially shifted by a slight time within a time corresponding to one pixel, Since the drive voltage according to the pixel value of the pixel corresponding to the clock is input to the light modulation element, the transition timing is shifted beyond the time corresponding to one pixel (or the transition beyond the distance corresponding to one pixel). The position cannot be shifted) and the above problem cannot be solved. Of course, it is conceivable to match the positions in the scanning direction of the plurality of irradiation regions by mechanical adjustment of each component of the image recording apparatus, but such adjustment is not easy. In addition, in an optical modulator in which a plurality of light modulation elements are arrayed on the same base plate, it may be impossible to match the positions in the scanning direction of the plurality of irradiation areas due to warpage of the base plate. .

  The present invention has been made in view of the above problems, and in a plurality of irradiation regions irradiated with light from a plurality of light modulation elements, correction of positional deviation in the scanning direction that greatly exceeds a distance corresponding to one pixel is performed. It is intended to be easily realized.

  The invention according to claim 1 is an image recording apparatus for recording an image on a recording medium by irradiation of light, wherein an optical modulator having a plurality of light modulation elements and light from the plurality of light modulation elements respectively. To a recording medium, a moving mechanism that moves a plurality of irradiation areas that are irradiated and arranged in a substantially straight line on the recording medium relative to the recording medium in a scanning direction that intersects the array of the plurality of irradiation areas. A plurality of pixels arranged in a column direction corresponding to the scanning direction in a target image that is a recording target of the recording medium, and the plurality of light modulation elements are respectively associated with a plurality of pixel columns included in the target image. A width of the region on the recording medium corresponding to one pixel in the scanning direction as a unit width, the reference position fixed relative to the plurality of irradiation regions on the recording medium and each irradiation region Before A dummy pixel indicating a non-drawing number that is increased or decreased from a predetermined number by α, where the difference between the amount of positional deviation in the scanning direction and α times the unit width (where α is a positive integer) is less than the unit width. An added pixel row is generated by adding to the head of the pixel row corresponding to each irradiation region, and a calculation unit that obtains the difference as a position correction shift amount for each irradiation region, while synchronizing with the moving mechanism And a control unit that controls each light modulation element based on the added pixel row and the position correction shift amount.

  A second aspect of the present invention is the image recording apparatus according to the first aspect, wherein each of the pixel columns of the target image has a plurality of pixel groups each having the same pixel value continuously in the column direction. The light output from the light modulation element for correcting the drawing deviation of the pixel group at each change point that is a position between two adjacent pixel groups in each added pixel column The shift amount for shifting the transition position is obtained based on the position correction shift amount and the line width correction shift amount for correcting the drawing width of the pixel group, and an integer obtained by dividing the shift amount by the unit width The pixel value of the pixel included in each added pixel column is changed so that each change point moves in the column direction by the number of pixels of the portion, and the shift amount corresponding to each change point is set to the value To a value equivalent to the decimal part of Wherein the control unit is, the controls each light modulator element on the basis of the shift amount of the after each addition already pixel columns and modifications after the change.

  According to a third aspect of the present invention, in the image recording apparatus according to the second aspect of the present invention, in the calculation unit, for each change point, based on a combination of pixel values of the two adjacent pixel groups. The shift amount before correction is obtained, and the calculation unit stores a pixel processing table indicating a shift amount of a change point for each of a plurality of combinations of two pixel values for each light modulation element. By referring to the pixel processing table using one table storage unit and a combination of two pixel values at each change point of each added pixel column, a movement amount of each change point is obtained and each of the change points is obtained. An image change unit that moves a change point in the column direction, and a correction shift amount table that indicates a shift amount after correction for each of the plurality of combinations of two pixel values for each of the light modulation elements. Second The corrected shift amount for each change point is obtained by referring to the correction shift amount table using a table storage unit and a combination of two pixel values at each change point of each added pixel column A shift amount acquisition unit.

  According to a fourth aspect of the invention, there is provided the image recording apparatus according to the third aspect, further comprising a holding unit that holds a recording medium, and the moving unit moves the holding unit to the optical modulator in the scanning direction. The plurality of light modulation elements perform drawing of the plurality of pixel columns included in the target image, and the holding unit moves relatively in a direction perpendicular to the scanning direction and along the recording medium. Then, the plurality of light modulation elements perform drawing of a plurality of other pixel columns included in the target image by relatively moving in a direction opposite to the time of drawing of the plurality of pixel columns, and the plurality of pixels Different pixel processing tables and correction shift amount tables are used for the respective light modulation elements at the time of drawing a row and at the time of drawing the other plurality of pixel rows.

  A fifth aspect of the present invention is the image recording apparatus according to any one of the first to fourth aspects, wherein the plurality of light modulation elements are each two or more light modulation elements. It is possible to switch between activation and deactivation for each element group, and the calculation unit adds a dummy pixel to the end of the pixel column corresponding to each irradiation region. In each of the at least one element group, the lengths of the corresponding added pixel columns are made equal.

  A sixth aspect of the present invention is the image recording apparatus according to any one of the first to fifth aspects, wherein each of the plurality of light modulation elements has at least one ribbon pair. The plurality of light modulation elements are arranged in one direction on the same base plate, and the amount of positional deviation in the scanning direction between the reference position and each irradiation region is an element, This is caused by warpage of the base plate in the normal direction.

  According to the present invention, it is possible to easily realize correction of positional deviation in the scanning direction that greatly exceeds a distance corresponding to one pixel in a plurality of irradiation regions.

  In the invention of claim 2, an image can be easily recorded on a recording medium while shifting the transition position beyond a distance corresponding to one pixel. In the invention of claim 3, the pixel processing table and the correction shift amount are recorded. By using the table, the shift of the transition position exceeding the distance corresponding to one pixel can be easily realized.

  According to the fourth aspect of the present invention, it is possible to accurately record an image on the recording medium in both the forward and backward paths of the reciprocating movement. In the fifth aspect of the present invention, each of the plurality of light modulation elements is activated. Even in the case of being configured with at least one element group serving as a switching unit for deactivation, an image can be appropriately recorded on the recording medium.

1 is a side view of an image recording apparatus according to a first embodiment. It is a top view of an image recording device. It is a figure which shows a spatial light modulator. It is a figure which shows the cross section of a light modulation element. It is a figure which shows the cross section of a light modulation element. It is a figure which shows the structure of a part of element drive element. It is a figure which shows a base clock and a delay clock. It is a block diagram which shows the structure of a modulator control part. It is a figure which shows the structure of conversion pixel data. It is a figure for demonstrating conversion pixel data. It is a figure which shows a reference | standard position address table. It is a figure which shows a correction shift amount table. It is a figure which shows a drive voltage table. It is a figure which shows the flow of the operation | movement which records an image on a board | substrate. It is a figure which shows the flow of the operation | movement which records an image on a board | substrate. It is a figure which shows the base plate of a spatial light modulator. It is a figure which shows the light modulation element in a several position in piles. It is a figure which shows the several irradiation area | region on a board | substrate. It is a figure for demonstrating the standard shift amount. It is a figure for demonstrating line | wire width correction | amendment shift amount. It is a figure for demonstrating the position correction shift amount. It is a figure which shows a pixel column. It is a figure which shows the added pixel row | line | column. It is a figure which shows the data structure of a pixel column. It is a figure which shows a base clock and a pixel row. It is a figure which shows a base clock and a pixel row. It is a figure which shows the structure of the image recording device which concerns on 2nd Embodiment. It is a figure which shows the internal structure of an optical head. It is a figure which shows the other example of a line | wire width correction shift amount and a position correction shift amount. It is a figure which shows the other example of the pixel count between base clocks.

  FIG. 1 is a side view of the image recording apparatus 1 according to the first embodiment of the present invention, and FIG. 2 is a plan view of the image recording apparatus 1. The image recording apparatus 1 is an apparatus (also referred to as a pattern drawing apparatus) that records an image by irradiating light on a photosensitive material on a glass substrate (hereinafter simply referred to as “substrate”) for a liquid crystal display device. As shown in FIGS. 1 and 2, the image recording apparatus 1 is a substrate that holds a substrate 9 on which a layer of a photosensitive material is formed on a main surface 91 (hereinafter referred to as “upper surface 91”) on the (+ Z) side. The holding unit 3 is provided on the base 11 so as to straddle the holding unit moving mechanism 2 that moves the substrate holding unit 3 in the X direction and the Y direction perpendicular to the Z direction, and the substrate holding unit 3 and the holding unit moving mechanism 2. A frame 12 that is fixed to the base 11 and a light irradiation unit 4 that is attached to the frame 12 and that emits modulated light to the photosensitive material on the substrate 9 are provided. Further, as shown in FIG. 1, the image recording apparatus 1 includes a control unit 6 that controls each component such as the holding unit moving mechanism 2 and the light irradiation unit 4.

  The substrate holding unit 3 has a stage 31 on which the substrate 9 is placed, a support plate 33 that rotatably supports the stage 31, and a rotation axis 321 perpendicular to the upper surface 91 of the substrate 9 on the support plate 33. A stage rotation mechanism 32 that rotates the stage 31 is provided.

  The holding unit moving mechanism 2 includes a sub-scanning mechanism 23 that moves the substrate holding unit 3 in the X direction in FIGS. 1 and 2 (hereinafter referred to as “sub-scanning direction”), and a support plate 33 via the sub-scanning mechanism 23. And a main scanning mechanism 25 that continuously moves the substrate holder 3 together with the base plate 24 in the Y direction perpendicular to the X direction (hereinafter referred to as “main scanning direction”). In the image recording apparatus 1, the holding unit moving mechanism 2 moves the substrate holding unit 3 in the main scanning direction and the sub-scanning direction parallel to the upper surface 91 of the substrate 9.

  As shown in FIGS. 1 and 2, the sub-scanning mechanism 23 is arranged on the lower side of the support plate 33 (that is, on the (−Z) side) parallel to the main surface of the stage 31 and perpendicular to the main scanning direction. A linear motor 231 extending in the scanning direction and a pair of linear guides 232 extending in the sub-scanning direction on the (+ Y) side and the (−Y) side of the linear motor 231 are provided. The main scanning mechanism 25 extends below the base plate 24 in the main scanning direction on the linear motor 251 extending in the main scanning direction parallel to the main surface of the stage 31 and on the (+ X) side and (−X) side of the linear motor 251. A pair of air sliders 252 and a linear scale (not shown) are provided.

  As shown in FIG. 2, the light irradiation unit 4 includes a plurality (eight in the present embodiment) of optical heads 41 arranged at an equal pitch along the sub-scanning direction and attached to the frame 12. As shown in FIG. 1, the light irradiation unit 4 includes a light source optical system 42 connected to each optical head 41, a UV light source 43 that emits ultraviolet light, and a light source driving unit 44. The UV light source 43 is a solid-state laser, and when the light source driving unit 44 is driven, ultraviolet light having a wavelength of 355 nm, for example, is emitted from the UV light source 43 and guided to the optical head 41 via the light source optical system 42.

  Each of the optical heads 41 emits light from the UV light source 43 downward, an optical unit 451 that reflects the light from the output unit 45 and guides it to the spatial light modulator 46, and the optical system 451. The spatial light modulator 46 that reflects and modulates the light emitted from the emitting portion 45, and the modulated light from the spatial light modulator 46 onto the photosensitive material provided on the upper surface 91 of the substrate 9. A guiding optical system 47 is provided.

  FIG. 3 is an enlarged view of the spatial light modulator 46. As shown in FIG. 3, the spatial light modulator 46 includes a plurality of diffraction grating type light modulation elements 461 that guide light from the UV light source 43 irradiated through the emitting unit 45 to the upper surface 91 of the substrate 9. . The light modulation element 461 is manufactured using a semiconductor device manufacturing technique, and is a diffraction grating capable of changing the depth of the grating. A plurality of flexible ribbons 461a and fixed ribbons 461b are alternately arranged in parallel on the light modulation element 461, and the plurality of flexible ribbons 461a can be individually moved up and down with respect to the reference plane on the back, and a plurality of fixed ribbons are arranged. The ribbon 461b is fixed with respect to the reference plane. As a diffraction grating type light modulation element, for example, GLV (Grating Light Valve) (registered trademark of Silicon Light Machines (Sunnyvale, Calif.)) Is known.

  FIG. A and FIG. B is a view showing a cross section of the light modulation element 461 in a plane perpendicular to the flexible ribbon 461a and the fixed ribbon 461b. FIG. As shown in A, the flexible ribbon 461a and the fixed ribbon 461b are located at the same height with respect to the reference surface 460a which is the main surface of the base plate (for example, a substrate formed of silicon) 460 (ie, flexible In the case where the ribbon 461a does not bend), the surface of the light modulation element 461 is flush, and the reflected light of the incident light L1 is derived as zero-order light (regularly reflected light) L2. On the other hand, FIG. B, when the flexible ribbon 461a bends to the reference surface 460a side with respect to the fixed ribbon 461b and the height difference between the flexible ribbon 461a and the fixed ribbon 461b is set to a predetermined value, the flexible ribbon 461a 461a becomes the bottom surface of the groove of the diffraction grating, and the first-order diffracted light L3 (and higher-order diffracted light) is derived from the light modulation element 461, and the zero-order light L2 disappears. In the actual light modulation element 461, by changing the height difference between the flexible ribbon 461a and the fixed ribbon 461b in a plurality of ways, the intensity of the 0th-order light L2 is changed in a plurality of ways. Tone light modulation is performed.

  In the light irradiation unit 4 shown in FIG. 1, the light from the UV light source 43 is converted into linear light (light having a light beam cross-section linear) by the light source optical system 42, and the line of the spatial light modulator 46 is passed through the emission unit 45. Irradiation is performed on a plurality of flexible ribbons 461a and fixed ribbons 461b (see FIG. 4.A and FIG. 4.B) arranged in a shape. In the light modulation element 461, when each adjacent one flexible ribbon 461a and fixed ribbon 461b is one ribbon pair, three or more ribbon pairs correspond to one pixel of a pattern to be drawn. Of course, the light modulation element 461 may be one ribbon pair, and one ribbon pair may correspond to one pixel. That is, each light modulation element 461 in the spatial light modulator 46 only needs to have at least one ribbon pair.

  In the light modulation element 461, the flexible ribbon 461a of the ribbon pair corresponding to each pixel of the pattern is controlled based on a signal from the modulator control unit 60 connected to each spatial light modulator 46, and a plurality of ribbon pairs are provided. It is possible to transition between a plurality of states that emit 0th-order light having different output light amounts (intensities). The zero-order light emitted from the light modulation element 461 is guided to the optical system 47, and the non-zero-order diffracted light (mainly the first-order diffracted light ((+1) -order diffracted light and (−1) -order diffracted light)) is the optical system 47. Guided in different directions. In order to prevent stray light from being generated, the first-order diffracted light is shielded by a light shielding unit (not shown).

  The zero-order light from the light modulation element 461 is guided to the upper surface 91 of the substrate 9 through the optical system 47, and thereby approximately along the X direction (that is, the sub-scanning direction) on the upper surface 91 of the substrate 9. The modulated light (including the case where the light intensity is approximately 0) is irradiated to each of the plurality of irradiation regions arranged in a straight line. As described above, the light modulation element 461 corresponding to each pixel can irradiate light on the substrate 9 with multiple gradations (including gradations in which drawing light is not irradiated on the substrate 9). Is done. As will be described later, in the plurality of irradiation areas, positional deviations in the main scanning direction are caused.

  In the image recording apparatus 1 shown in FIGS. 1 and 2, the light modulated from the light modulation element 461 of the light irradiation unit 4 is applied to the substrate 9 moved in the main scanning direction by the main scanning mechanism 25 of the holding unit moving mechanism 2. Is irradiated. In other words, the main scanning mechanism 25 sets the positions of the plurality of irradiation regions (that is, the irradiation positions) irradiated with the light from the plurality of light modulation elements 461 relative to the substrate 9 continuously. The moving mechanism moves in the main scanning direction intersecting the array of the plurality of irradiation areas. In the image recording apparatus 1, the irradiation position on the substrate 9 may be moved in the main scanning direction by moving the optical head 41 in the main scanning direction without moving the substrate 9. In the image recording apparatus 1, the modulation of the light from the light modulation element 461 is controlled by the modulator control unit 60 of the control unit 6, whereby an image to be recorded on the substrate 9 (hereinafter referred to as “target image”). .) Is recorded on the substrate 9.

  FIG. 5 is a diagram showing a configuration of a part of the modulator control unit 60, and a part of elements related to driving of the respective light modulation elements 461 in the modulator control unit 60 (hereinafter referred to as “element drive element 61”). Is shown. The element driving element 61 uses the registers 610 and 611, the shift unit 616, the D / A converter 612, and the output from the D / A converter 612 as the actual driving voltage of the light modulation element 461 (hereinafter referred to as “actual driving voltage”). .), And the shift unit 616 includes a register 613, a counter 614, and a comparator 615.

  The modulator controller 60 further includes a clock generator (not shown), and a signal from the linear scale of the main scanning mechanism 25 is input to the clock generator. Then, as shown in the upper part of FIG. 6, the main scanning is performed by a certain distance (a distance set in image recording described later, hereinafter referred to as “set distance”) on the substrate 9. The base clock 303 is generated in the clock generation unit every time the direction (Y direction) moves, and is input to the register 610 and the register 613 and the counter 614 of the shift unit 616 shown in FIG. In FIG. 5, a base clock sequentially input to the registers 610 and 613 and the counter 614 is indicated by an arrow denoted by reference numeral 303 (delay clock 304, drive voltage data 301, shift delay number data 302, and shifted clock described later). The same applies at 305).

  In the clock generation unit, as shown in the middle part of FIG. 6, the irradiation position on the substrate 9 moves by a distance (for example, 10 nanometers (nm)) obtained by equally dividing the set distance into a predetermined number (for example, 200). A delay clock 304 is generated every time and is input to the counter 614. Since the moving speed of the substrate 9 in the main scanning direction by the main scanning mechanism 25 is substantially constant, the horizontal axis can be regarded as time in each of the upper and middle stages of FIG. 6 (FIG. 9 described later). 17 to 19, FIG. 23, FIG. 24, FIG. 27, and FIG. 28).

  In the register 610 of FIG. 5, drive voltage data 301 indicating a target voltage (hereinafter referred to as “target drive voltage”) that the actual drive voltage gradually changes with time and finally reaches is responded to the base clock 303. The drive voltage data 301 is output from the register 610 to the register 611 in synchronization with the base clock 303. The shift delay number data 302 used for adjusting the operation position (operation timing) of the light modulation element 461 is sequentially input to the register 613 of the shift unit 616 in response to the base clock 303.

  The shift delay number data 302 is input from the register 613 to the comparator 615 in synchronization with the base clock 303. Each time the delay clock 304 is input to the counter 614, the count number of the delay clock 304 in the counter 614 is output to the comparator 615, and the value indicated by the shift delay number data 302 matches the count number from the counter 614. A clock 305 delayed from the base clock 303 (hereinafter referred to as “shifted clock”) 305 is output from the comparator 615 to the register 611. As a result, an analog signal of the drive voltage data 301 is output from the register 611 via the D / A converter 612. The count number of the delay clock 304 in the counter 614 is reset every time the base clock 303 is input.

  The drive voltage data 301 for each shifted clock 305 corresponds to the target drive voltage when the light modulation element 461 is driven once, and the output from the D / A converter 612 is input to the current source 51 and converted to a current. Further converted. One end of the current source 51 is connected to the high potential Vcc side via the resistor 52, and the other end is grounded.

  Both ends of the current source 51 are connected to the flexible ribbon 461 a and the reference surface 460 a of the light modulation element 461 through the connection pad 53. Therefore, when the drive voltage data 301 is converted into a current via the D / A converter 612 and the current source 51, it is converted into an actual drive voltage between the connection pads 53 due to a voltage drop due to the resistor 52. As described above, the element driving element 61 shifts the operation position of the light modulation element 461 from the position corresponding to the base clock 303 based on the shift delay number data 302 while setting the distance corresponding to the delay clock 304 to the minimum resolution. It is possible to (adjust).

  Since the connection pads 53 have a stray capacitance, the actual drive voltage (actual drive voltage) between the connection pads 53 changes according to the time constant between the connection pads 53 and moves toward the target drive voltage with time. .

  FIG. 7 is a block diagram showing a configuration of the modulator control unit 60. In addition to the element driving element 61 described above, the modulator control unit 60 includes a CPU for performing various calculations and a main calculation unit 62 having a memory for storing various types of information, and an FPGA (Field Programmable) that is a programmable electronic circuit. Gate Array) control element 63 (shown by a broken line block in FIG. 7). Actually, the modulator control unit 60 is provided with one element driving element 61 and one FPGA control element 63 for each light modulation element 461. In FIG. 7, it corresponds to one light modulation element 461. Only the element driving element 61 and the FPGA control element 63 are shown.

  The main calculation unit 62 includes an additional pixel number acquisition unit 620 that acquires a parameter for correcting a positional deviation in the main scanning direction of a plurality of irradiation areas, and a table generation unit 622 that generates various tables used in image recording. , And a shift amount excess detection unit 621 that detects a condition related to table generation at the time of table generation to be described later. In the FPGA control element 63, a memory 630 for storing an additional pixel number 6302 and a pixel processing table 6301 used for changing the target image (addition or processing of a pixel) and a dummy pixel to be described later are added to the target image using the additional pixel number 6302. A pixel addition unit 631 to be added, a pixel column processing unit 632 that changes the pixel value of the pixel of the target image using the pixel processing table 6301, and output data that converts the changed image into a data format for the element driving element 61 The function of the generation unit 633 is realized.

  Each element driving element 61 includes a modified shift amount acquisition unit 618 that acquires the shift delay number data 302, a driving voltage acquisition unit 619 that acquires the driving voltage data 301, and a memory 617, and is provided for each light modulation element 461. The correction shift amount table 6171, which will be described later, the reference position address table 6172 that is common to all the light modulation elements 461, and the drive voltage table 6173 that indicates the target drive voltage corresponding to the output light quantity of a plurality of gradations at the time of drawing. Is input from the main calculation unit 62 to the memory 617 and stored therein.

  Here, in the target image that is a recording target in the image recording apparatus 1, a plurality of pixels are arranged in the column direction corresponding to the main scanning direction and the row direction corresponding to the sub-scanning direction. ), With a plurality of pixels arranged in the column direction as a pixel column, a plurality of light modulation elements 461 are respectively associated with a plurality of pixel columns included in the target image, and each light modulation element 461 draws one pixel column. Done. Each pixel column is a set of a plurality of pixel groups each having the same pixel value continuously in the column direction (that is, each pixel column is a plurality of pixel groups each being a set of two or more pixels) The position between two adjacent pixel groups in the pixel row is a change point indicating the transition of the output light amount irradiated from the light modulation element 461 to the irradiation region. In this embodiment, it is assumed that the target image is a four-value image of 1 to 4, but of course, it is an image having a gradation level of 5 or more, or an image having a gradation level of 2 or 3. May be.

  In the pixel addition section 631 connected to the element driving element 61 of each light modulation element 461, pixel column data (hereinafter referred to as “pixel column data”) 691 corresponding to the light modulation element 461 is run length data. As described later, after adding dummy pixels of the number indicated by the additional pixel number 6302 as described later, the dummy pixels are output to the pixel column processing unit 632, and the pixel column data 691 is processed using the pixel processing table 6301. The output data generation unit 633 converts the processed pixel column data 691 into a data format for the element driving element 61, and sequentially outputs the converted pixel data 692 to the element driving element 61 every time the base clock 303 is generated. The

  Here, as shown in the upper part of FIG. 6 showing the base clock 303 and the lower part of FIG. 6 showing the pixels of one pixel column, in the image recording apparatus 1, a period between two adjacent base clocks 303 (hereinafter, In the “base clock period”), two or more pixels 71 (four pixels 71 in the lower example in FIG. 6) in each pixel column of the target image are subject to drawing control. In other words, the set distance by which the irradiation position of light from the light modulation element 461 moves in the main scanning direction during the base clock period, where the number of pixels subject to drawing control in the base clock period is the number of pixels between base clocks. Is a distance corresponding to the pixel 71 of the number of pixels between the base clocks (a distance indicated by an arrow with a symbol W in the upper part of FIG. 6). In the following description, in the upper and lower stages of FIG. 6, the position in the main scanning direction corresponding to the head of each pixel 71 of the target image (the position indicated by the arrow with reference A1) is referred to as the “reference position” of the pixel. The distance between two adjacent reference positions (that is, the distance obtained by dividing the set distance by the number of pixels between the base clocks and the width in the main scanning direction of the area on the substrate 9 corresponding to one pixel). This is called “unit width”. In the lower part of FIG. 6, the unit width is indicated by an arrow with a symbol T. The unit width can be regarded as a logical minimum resolution in drawing.

  In the image recording apparatus 1, since the shifted clock 305 is output only once in the base clock period in the configuration of the element driving element 61 shown in FIG. 5, the transition of the output light amount from the light modulation element 461 is the base The conversion pixel data 692 that is output only once in the clock period and is output in accordance with the base clock 303 is the immediately preceding pixel in the number of pixels between base clocks in the base clock period, as shown in FIG. The number of the pixel whose pixel value changes from the pixel and the pixel value of the pixel (hereinafter referred to as “changed pixel number” and “changed pixel value”, respectively) are shown.

  For example, the number of pixels between the base clocks is 4, and as shown in the lowermost stage in FIG. 9, in the four pixels 71 in the certain base clock period (pixels 71 surrounded by a thick rectangle in the lowermost stage in FIG. 9), When the pixel value changes from 1 to 2 between the third pixel 71 and the fourth pixel 71 (the pixel 71 having a pixel value of 1 is shown in white at the bottom of FIG. 2 is marked with a parallel diagonal line in the second to fifth rows from the bottom of FIG. 9 and in FIGS. 17 to 19, 23, and 24). 4 and 2, and when the pixel value changes from 1 to 2 between the second pixel 71 and the third pixel 71 as shown in the second row from the bottom in FIG. The numbers and post-change pixel values are 3 and 2, respectively. As shown in the third row from the bottom, when the pixel value changes from 1 to 2 between the first pixel 71 and the second pixel 71, both the changed pixel number and the changed pixel value are 2. It is said.

  Further, as shown in the fourth row from the bottom in FIG. 9, when the pixel value changes from 1 to 2 between the first pixel 71 and the fourth pixel 71 in the immediately preceding base clock period, The changed pixel number and the changed pixel value are 1 and 2, respectively. As shown in the fifth row from the bottom (second row from the top) in FIG. The changed pixel number is 1, and the changed pixel value is the same as the pixel value of the last pixel in the immediately preceding base clock period. The change pixel number can be regarded as a logical coordinate value with the unit width T as a unit.

  FIG. 10 shows the reference position address table 6172. As shown in FIG. The reference position address table 6172 shown in FIG. 10 is the distance in the main scanning direction from the position where the previous base clock 303 is generated to the reference position for each of the first to fourth pixels (hereinafter referred to as “reference position address”). Is a table showing the count number of the delay clock 304 (see the top row in FIG. 9). In FIG. 10, the reference position addresses of the first to fourth pixels are denoted as “first reference position address”, “second reference position address”, “third reference position address”, and “fourth reference position address”, respectively. Yes.

  FIG. 11 is a diagram showing a corrected shift amount table 6171. The correction shift amount table 6171 is generated by correcting a correction table described later, and shift amounts (values derived from the correction table described later are corrected) for each of a plurality of combinations of two pixel values. (This is a value obtained by (changing), and is hereinafter referred to as a “correction shift amount”). In practice, the correction shift amount is represented by the count number of the delay clock 304. . In FIG. 11, the correction shift amount for the combination of the pixel value M and the pixel value N is indicated as “the correction shift amount when the pixel value M → N changes” (where M and N are 1 to 4). The correction shift amount is smaller than the count number corresponding to the distance between two adjacent reference positions (that is, the unit width T).

  By referring to the reference position address table 6172 in FIG. 10 by using the change pixel number of the converted pixel data 692 input for each base clock 303 from the output data generation unit 633, the corrected shift amount acquisition unit 618 in FIG. One reference position address is specified. The corrected shift amount acquisition unit 618 stores the changed pixel value of the converted pixel data 692 input by the immediately preceding base clock 303, and uses the immediately preceding changed pixel value and the current changed pixel value. Thus, one correction shift amount is specified by referring to the correction shift amount table 6171 in FIG. Then, a value obtained by adding the identified reference position address and the corrected shift amount (both are expressed as the count number of the delay clock 304 as described above) is obtained as the shift delay number, and the shift of FIG. The shift delay number data 302 is input to the register 613 of the unit 616.

  FIG. 12 is a diagram showing a drive voltage table 6173. The drive voltage table 6173 is a table indicating target drive voltages corresponding to a plurality of pixel values, and the drive voltage acquisition unit 619 in FIG. 7 uses the changed pixel values of the converted pixel data 692 to drive the drive voltage table. By referring to 6173, the drive voltage corresponding to the changed pixel value is specified. In FIG. 12, the drive voltages corresponding to the changed pixel values 1 to 4 are respectively “first gradation drive voltage”, “second gradation drive voltage”, “third gradation drive voltage”, and “fourth gradation”. "Drive voltage". The identified drive voltage is input to the register 610 of FIG.

  As described above, the drive voltage data 301 and the shift delay number data 302 are generated from the converted pixel data 692 in the element drive element 61 of FIG. 7, thereby changing the output light amount from the light modulation element 461 to the changed pixel value. It is possible to shift to the corresponding gradation and shift (adjust) the transition position. Details of the additional pixel number 6302, the pixel processing table 6301, and the corrected shift amount table 6171 will be described later.

  Next, the operation in which the image recording apparatus 1 records an image on the substrate 9 will be described with reference to FIG. A and FIG. A description will be given with reference to FIG. In the image recording apparatus 1, first, the operator prepares the positional deviation amount of the irradiation region and the line width correction shift amount for correcting the drawing width of the pixel group for each light modulation element 461, as shown in FIG. The data is input to the main calculation unit 62 (step S10). In FIG. 7, an arrow denoted by reference numeral 681 indicates the positional deviation amount and the line width correction shift amount of the irradiation region.

  Here, the positional deviation amount of the irradiation region will be described (the line width correction shift amount will be described later). FIG. 14 is a view showing the base plate 460 of the spatial light modulator 46, and shows a cross section of the base plate 460 in a plane perpendicular to the flexible ribbon 461a and the fixed ribbon 461b of FIG. In FIG. 14, the warp of the base plate 460 is emphasized. Further, in FIG. 14, illustration of the flexible ribbon 461a and the fixed ribbon 461b is omitted.

  The base plate 460 on which a large number of ribbons of the plurality of light modulation elements 461 are arranged in one direction is influenced by various thin films such as a vapor deposition film formed on the reference surface 460a when the spatial light modulator 46 is manufactured (compression). 14), the direction perpendicular to the reference surface 460a (more precisely, the average normal line of the reference surface 460a) throughout the arrangement direction of the ribbon (lateral direction in FIG. 14), as shown in FIG. (Hereinafter referred to simply as “normal direction”), warping called “die bow” occurs. As a result, the positions in the normal direction are different at a plurality of positions on the reference surface 460a in the arrangement direction of the ribbons. For example, in FIG. 14, the difference in the normal direction between the position denoted by γ1 and the position denoted by γ2 is D1, and the difference in the normal direction between the position γ1 and the position denoted by γ3 is D2. . As described above, the flexible ribbon 461a and the fixed ribbon 461b are formed on the reference surface 460a, so that the surface of the light modulation element 461 at the positions γ1, γ2, and γ3 (the surfaces of the flexible ribbon 461a and the fixed ribbon 461b). As for the base plate 460, there is a displacement in the normal direction. Note that the cross-sectional shape of the base plate 460 in a plane perpendicular to the ribbon is not constant, and has various shapes for each spatial light modulator 46.

  FIG. 15 is a diagram in which the light modulation elements 461 are overlapped at positions γ1, γ2, and γ3 when viewed along the ribbon arrangement direction. In FIG. 15, each light modulation element 461 is assigned the same reference numeral as its position γ1, γ2, γ3.

  In the spatial light modulator 46, light is incident along an optical axis J1 (indicated by a one-dot chain line in FIG. 15) inclined with respect to the normal direction on a plane perpendicular to the ribbon arrangement direction. The zero-order light from each light modulation element 461 of the spatial light modulator 46 is reflected in a direction parallel to the optical axis denoted by reference numeral J2 in FIG. As described above, the zero-order light from the plurality of light modulation elements 461 is irradiated on the plurality of irradiation regions arranged approximately linearly on the substrate 9 along the sub-scanning direction perpendicular to the main scanning direction. 15, the optical path of the zero-order light from the plurality of light modulation elements 461 in the direction perpendicular to the optical axis J <b> 2 and the arrangement direction of the ribbon (in FIG. 15, the position is indicated by the lines labeled P <b> 1 and P <b> 2 in FIG. 15. (The optical paths of the 0th-order light from the light modulation elements 461 of γ1 and γ2 are shown.) Due to the deviation, the positions (center positions) of the plurality of irradiation regions in the main scanning direction do not coincide on the substrate 9. .

  Further, depending on the mounting accuracy of the spatial light modulator 46 in the image recording apparatus 1, the arrangement direction of the ribbon may be slightly inclined with respect to the ideal direction. In this case, the arrangement of a plurality of irradiation regions on the substrate 9 is arranged. The direction is also slightly inclined with respect to the direction perpendicular to the main scanning direction.

  As described above, in the image recording apparatus 1, the positions of the plurality of irradiation areas in the main scanning direction are shifted from each other due to the warp in the normal direction of the base plate 460 and the attachment state of the spatial light modulator 46. On the upper surface 91 of the substrate 9, a predetermined position relatively fixed with respect to a plurality of (all) irradiation areas (for example, a central position in a range in the X direction and the Y direction where the plurality of irradiation areas exist) Or a virtual position that moves on the substrate 9 together with the plurality of irradiation regions without changing the positional relationship with the plurality of irradiation regions, such as the position of the irradiation region on the most (+ Y) side. The distance in the main scanning direction between each irradiation area and the irradiation area is acquired as the positional deviation amount of the irradiation area. The amount of positional deviation can be acquired by, for example, providing a light detection unit on the stage 31 and measuring the positions in the main scanning direction of the irradiation regions of the light from all the light modulation elements 461. Further, when the spatial light modulator 46 is not inclined (that is, the arrangement direction of the ribbon is an ideal direction), the positional deviation amount of each irradiation region is in the normal direction of the spatial light modulator 46. You may obtain | require based on the position (bending amount) of each light modulation element 461. FIG. The line width correction shift amount will be described together with the processing content of step S11 below.

  When the position shift amount and the line width correction shift amount of the irradiation region are input, the additional pixel number acquisition unit 620 of the main calculation unit 62 in FIG. 7 applies the pixel column corresponding to each light modulation element 461 in the process described later. The number of non-drawing pixels (hereinafter referred to as “dummy pixels”) to be added is obtained as the number of additional pixels, and the position correction used for correcting the positional deviation of the irradiation region at the time of drawing based on the pixel column data A shift amount is acquired (step S11).

  FIG. 16 is a diagram showing a plurality of irradiation areas on the substrate 9. As described above, in the image recording apparatus 1, the positions of the plurality of irradiation areas in the main scanning direction do not coincide with each other, and the three irradiation areas in FIG. 16 relate to the main scanning direction (Y direction). The center of the irradiation area indicated by the solid circle with the reference numeral 92a in the inside is the same position as the reference position, and the irradiation area indicated by the solid circle with the reference numeral 92b is the reference position (here, the irradiation area 92a). The irradiation area indicated by a solid circle with a reference numeral 92c is only 7/3 times the unit width T from the reference position. It is located on the (−Y) side. In the present embodiment, for convenience of explanation, the irradiation region 92a is assumed to be the same position as the reference position in the main scanning direction. However, as described above, the reference position is relatively relative to a plurality of irradiation regions. The position can be any fixed position, and is not necessarily the same position as any one of the irradiation areas.

  In the additional pixel number acquisition unit 620, a predetermined reference number (8 in the present embodiment) is set with respect to the reference position, and the front side in the relative movement direction (((the position of the irradiation region 92a)) (( For the irradiation region 92b located on the + Y) side), the unit width T is larger than 7/3 times the unit width T, which is the amount of displacement in the main scanning direction between the irradiation region 92b and the reference position. Three times the smallest unit width T among the integer multiples is specified, and a value 5 obtained by subtracting a value 3 obtained by dividing three times the unit width T by the unit width T from the reference number 8 is obtained as the number of additional pixels. Also, a value obtained by subtracting 7/3 times the unit width T, which is a positional deviation amount, from 3 times the unit width T (that is, 2/3 times the unit width T) is acquired as the position correction shift amount.

  For the irradiation area 92c located on the rear side ((−Y) side) in the relative movement direction with respect to the reference position, a unit width that is a displacement amount in the main scanning direction between the irradiation area 92c and the reference position. Among integral multiples of the unit width T smaller than 7/3 times T, twice the maximum unit width T is specified, and a value 2 obtained by dividing twice the unit width T by the unit width T is a reference number 8 A value 10 added to is obtained as the number of additional pixels. In addition, a value obtained by subtracting twice the unit width T from 7/3 times the unit width T, which is the positional deviation amount (that is, 1/3 times the unit width T) is acquired as the position correction shift amount. For the irradiation area 92a in which the position in the main scanning direction is the same as the reference position, the reference number is determined as the additional pixel number, and the position correction shift amount is acquired as zero.

  As described above, in the main calculation unit 62, the difference between the displacement amount in the main scanning direction between each irradiation region and the reference position and α times the unit width (where α is a positive integer) is (0). As described above, the number that is increased or decreased from the reference number by α corresponding to less than the unit width is obtained as the number of additional pixels, and the difference is acquired as the position correction shift amount for the irradiation region. Actually, the reference number is determined so that each additional pixel number is sufficiently larger than the inter-base clock pixel number. In the additional pixel number acquisition unit 620, each additional pixel number 6302 is input to and stored in the memory 630 of the corresponding FPGA control element 63, and the line width correction shift amount and the position correction shift amount with respect to each light modulation element 461. Is generated.

  Here, the above-described line width correction shift amount will be described. The line width correction shift amount refers to two regions on the substrate 9 corresponding to two pixel groups sandwiching the change point (corresponding to two pixel groups) for each change point in the pixel column corresponding to each light modulation element 461. In order to correct the positional deviation in the main scanning direction depending on the pixel values of the two pixel groups at the boundary between the two regions where the pattern to be formed is), the transition position of the output light amount from the light modulation element 461 is set. This indicates the shift amount to be shifted. The cause of the positional shift depending on the two pixel groups sandwiching the change point is that the time until the state of the flexible ribbon 461a is stabilized when the deflection amount changes depends on the combination of the pixel values of the two pixel groups. For example, the length of the irradiation region of the light modulation element 461 in the main scanning direction is different from those of other light modulation elements 461. The line width correction shift amount is acquired by, for example, actually drawing a pattern extending in the sub-scanning direction on the dummy substrate.

  In the correction table shown in Table 1, the pixel value of the pixel immediately before the target pixel of interest and the pixel value of the target pixel (in Table 1, “previous pixel value” and “current pixel value” are described, respectively). ), “Standard shift amount”, “line width correction shift amount”, and “position correction shift amount” are set. Table 1 shows only the case where the “previous pixel value” and the “current pixel value” are a combination of 1 and 1, a combination of 1 and 2, a combination of 2 and 1, and a combination of 2 and 2. However, in practice, the “standard shift amount”, “line width correction shift amount”, and “position correction” are also used for combinations in which “previous pixel value” and “current pixel value” are 3 and 4, respectively. “Shift amount” is set.

  FIG. 17 is a diagram for explaining the standard shift amount in the correction table. The upper part of FIG. 17 shows the base clock 303, the middle part shows the target drive voltage, and the lower part shows the pixel column. Here, it is assumed that the number of pixels between base clocks is 4 as shown in the upper and lower stages of FIG. 17, and in the upper stage of FIG. 17, the set distance W is set to the number of pixels between base clocks as in the upper stage of FIG. The divided unit width is indicated by an arrow with a symbol T.

  The standard shift amount is the front side of the relative movement direction of the irradiation position from the position corresponding to the change point with respect to the substrate 9 (when moving in the main scanning direction), even when there is no need to correct the above-described drawing deviation. It is for moving to the front side of FIG. For example, in the example shown in the middle and lower stages of FIG. 17, the target drive voltage for the light modulation element 461 is changed from the first gradation drive voltage V1 corresponding to the pixel value 1 to the second gradation drive voltage V2 corresponding to the pixel value 2. The transition position to be changed is the position of the change point from the white pixel 71 with the pixel value 1 to the pixel 71 with the pixel value 2 with parallel diagonal lines (that is, the reference position A1a of the first pixel 71 in the pixel group with the pixel value 2). On the other hand, it moves by 1/2 of the unit width T which is the standard shift amount. As described above, a correction table is individually prepared for each of all the light modulation elements 461, but the standard shift amount is made equal in all combinations of pixel values of all the correction tables.

  FIG. 18 is a diagram for explaining the line width correction shift amount in the correction table. As described above, the line width correction shift amount is for correcting a drawing shift depending on a combination of pixel values of two adjacent pixel groups. For example, the pixel value is changed from 1 to 2 at the change point. When changing, the transition position of the output light amount from the light modulation element 461 (for example, the position depending on the rise time of the output light amount) is set to the irradiation position by 1/3 times the unit width T by referring to Table 1. (+ (1/3) T) indicating the movement to the front side in the relative movement direction is specified, and this corresponds to the region corresponding to the pixel group having the pixel value 1 and the pixel group having the pixel value 2 on the substrate 9. The deviation of the boundary position with the area to be corrected is corrected. When the pixel value changes from 2 to 1 at the change point, referring to Table 1, the transition position of the output light amount from the light modulation element 461 (for example, a position depending on the fall time of the output light amount). (− (1/3) T) is specified, which indicates that the irradiation position is moved to the rear side in the relative movement direction of the irradiation position by 1/3 times the unit width T. Thus, a pixel having a pixel value of 2 on the substrate 9 is specified. The shift of the boundary position between the area corresponding to the group and the area corresponding to the pixel group having the pixel value of 1 is corrected.

  The second stage from the top in FIG. 18 shows the change in the target drive voltage in the middle stage in FIG. 17 (the same thing is shown by a broken line in the third stage from the top in FIG. 18. The same applies to the stage), and a shift based on the line width correction shift amount in Table 1 is further added. Here, as shown at the bottom of FIG. 18, the pixel values of the adjacent three pixel groups change in the order of 1, 2, and 1, and the number of pixels of the pixel group having the central pixel value of 2 is set to 5. Therefore, the distance at which the target drive voltage of the light modulation element 461 is set to the second gradation drive voltage V2 in the second stage from the top in FIG. 18 is a distance corresponding to five pixels (5 in unit width T). 2) times the unit width T, and the width in the main scanning direction of the region on the substrate 9 corresponding to the pixel group having the pixel value of 2 is thereby corrected. Thus, the line width correction shift amount in the correction table is substantially for correcting the width (line width) in the main scanning direction of the region on the substrate 9 corresponding to the pixel group of each pixel value. It has become.

  FIG. 19 is a diagram for explaining the position correction shift amount in the correction table. The position correction shift amount is for correcting a shift (shift in the main scanning direction) between the irradiation area of each light modulation element 461 and another irradiation area in cooperation with an additional operation of dummy pixels having the number of additional pixels described later. belongs to. As described above, the position correction shift amount is acquired individually for each light modulation element 461, and is the same value for all combinations of the pixel values of the two pixel groups. For example, in the example shown in the second stage from the top of FIG. 18 (the same thing is shown by the one-dot chain line in the third stage from the top of FIG. 19), the position correction shift amount (+ ( If a shift by 1/3) T) is added, the pixel value changes from 1 to 2 at the change point and the pixel value changes from 2 to 1 at the change point. As shown in the second stage, the transition position of the output light amount from the light modulation element 461 further moves to the front side ((+ Y) side) in the relative movement direction of the irradiation position by 1/3 times the unit width T. Become. As a result, the drawing deviation from the ideal position of the pixel group is corrected, and using all the light modulation elements 461, for example, it is possible to draw a line with a certain width extending straight in the sub-scanning direction (X direction). Become.

  However, in this case, the position where the target drive voltage of the light modulation element 461 is changed from the first gradation drive voltage V1 to the second gradation drive voltage V2 (that is, the transition position of the output light amount) is the lowermost stage in FIG. Is larger than the unit width T and not more than twice the unit width T with respect to the position of the change point from the pixel 71 having the pixel value 1 to the pixel 71 having the pixel value 2 (reference position A1a of the pixel 71a). The shift amount of the transition position of the output light amount from the light modulation element 461 exceeds the distance corresponding to one pixel. Thereby, the transition timing of the output light amount with respect to the change point (reference position A1a) from the pixel 71 having the pixel value 1 to the pixel 71 having the pixel value 2 is included in the base clock period next to the base clock period to which the change point belongs. End up. As described above, since the count number of the delay clock 304 in the counter 614 in FIG. 5 is reset every time the base clock 303 is input, the image recording apparatus 1 in FIG. Based on the column, the target drive voltage cannot be changed as shown in the second row from the top in FIG.

  Therefore, as will be described in detail in the following description, in the image recording apparatus 1, by changing the pixel value of the pixel 71a surrounded by the bold rectangle in the lowermost stage of FIG. A process of moving (delaying) the change point to 2 by one pixel is performed, and a process of obtaining a corrected shift amount with respect to the changed change point is performed.

  When the correction table is generated by acquiring the number of additional pixels and the position correction shift amount in the image recording apparatus 1, the number of pixels between base clocks (or the setting) used in the image recording operation by the main calculation unit 62 in FIG. (Distance) is determined (step S12), the number of pixels between base clocks is input to the output data generation unit 633, and a reference position address table 6172 corresponding to the number of pixels between base clocks is input to the element driving element 61. The Actually, it is confirmed whether or not the process in step S12 is to change the number of pixels between base clocks (hereinafter referred to as “the number of pixels between initial base clocks”) preset for the image recording apparatus 1. When the change is confirmed, the number of pixels between base clocks to be actually used is determined. Here, the number of pixels between the initial base clocks is set as 5, and the predetermined processing is performed. It shall be changed to 4. Details of the processing in step S12 will be described later.

  Subsequently, the main calculation unit 62 performs processing related to generation of the pixel processing table 6301 and the corrected shift amount table 6171. First, the shift amount excess detection unit 621 in FIG. 7 adds the standard shift amount, the line width correction shift amount, and the position correction shift amount in each combination of the two pixel values in Table 1, as shown in Table 2. A total shift amount is obtained (step S13).

  Subsequently, in all combinations of two different pixel values (in Table 2, a combination of pixel value 1 and pixel value 2 and a combination of pixel value 2 and pixel value 1), the standard shift amount, the line width correction shift amount, and the position It is confirmed whether or not there is a total shift amount based on the correction shift amount that exceeds the unit width T corresponding to one pixel. Here, only in the combination in which the previous pixel value and the current pixel value are 1 and 2, respectively, the total shift amount is (+7/6) times the unit width T and is larger than 1 time the unit width T. And it is confirmed that it becomes 2 times or less. Then, in the table generation unit 622, “pixel processing number” is set to (+1) in the combination in which the previous pixel value and the current pixel value are 1 and 2, respectively, and “pixel processing number” is set to 0 in the other combinations. A pixel processing table 6301 shown in Table 3 is generated.

  The pixel processing number indicates the amount of movement of the change point between two adjacent pixel groups. In the pixel processing table 6301 in Table 3, the pixel is changed with respect to the change point at which the pixel value changes from 1 to 2. When the processing number becomes (+1), processing of a pixel column that delays the change point by one pixel is instructed. For other combinations of pixel values, the pixel processing number becomes 0, so It is instructed not to perform processing. The pixel processing table 6301 is input and stored in the memory 630 of the FPGA control element 63 in FIG. 7 (step S14). If the total shift amount is larger than α times the unit width T (where α is an integer of 1 or more) and not more than (α + 1) times, the pixel processing number is α.

  The table generation unit 622 obtains a value obtained by multiplying the corresponding pixel processing number by the unit width T in a combination of pixel values in which the total shift amount is larger than the unit width T and the pixel processing number is other than zero. A value obtained by subtracting the value from the total shift amount (that is, a value obtained by multiplying the decimal part of β in the total shift amount expressed as β times the unit width T by the unit width T) is obtained as the corrected shift amount. Further, for a combination of pixel values whose total shift amount is smaller than the unit width T, the total shift amount is used as the correction shift amount as it is. Therefore, in the example of Table 2, the correction shift amount is (+1/6) times the unit width T in the combination in which the previous pixel value and the current pixel value are 1 and 2, respectively, and other pixel value combinations The total shift amount is directly used as the correction shift amount, and a correction shift amount table 6171 shown in Table 4 is generated. The corrected shift amount table 6171 is inputted and stored in the memory 617 of the element driving element 61 in FIG. 7 (step S15). If there is a combination of the same two pixel values where the total shift amount exceeds the unit width T, the unit width T is included in the decimal part of β in the total shift amount expressed as β times the unit width T. A value obtained by multiplying by is used as the correction shift amount. In practice, the corrected shift amount is changed to a value close to an integral multiple of the shift amount corresponding to the resolution of the delay clock 304, and as described above, the shift delay number which is the count number of the delay clock 304 is set to the element. It can be given by the drive element 61.

  As described above, when the number of additional pixels, the pixel processing table 6301, and the correction shift amount table 6171 are prepared, the substrate 9 starts to move at a constant speed in the main scanning direction (step S16) and is controlled. Data of a target image stored in an image memory (not shown) included in the unit 6 is input to the modulator control unit 60. As described above, in the modulator control unit 60 of FIG. 7, pixel column data 691 corresponding to each pixel adding unit 631 is input.

  In the pixel addition unit 631, the number of dummy pixels indicated by the additional pixel number 6302 stored in the memory 630 is added to the head of the pixel column indicated by the pixel column data 691 (step S17). For example, in the pixel addition unit 631 corresponding to the irradiation region 92a shown in FIG. 16, the reference number 8 is set as the number of additional pixels as described above, and eight dummy pixels 72 (indicated by parallel diagonal lines in FIG. 20). Is added to the head of the right pixel column 691a in FIG. Further, in the pixel addition unit 631 corresponding to the irradiation region 92b that is located on the (+ Y) side of the irradiation region 92a and whose positional shift amount is 7/3 times the unit width T, the positional shift amount is expressed in unit width. The number 5 obtained by subtracting the larger number of the two integers 2 and 3 whose difference from the divided value is less than the unit width from the reference number 8 is the additional pixel number, and the five dummy pixels 72 are It is added to the head of the center pixel row 691b in FIG. Further, in the pixel addition unit 631 corresponding to the irradiation region 92c that is located on the (−Y) side of the irradiation region 92a and whose positional deviation amount is 7/3 times the unit width T, the positional deviation amount is set to the unit width. The number of additional pixels is 10 by adding the smaller number of the two integers 2 and 3 whose difference from the divided value is less than the unit width to the reference number 8, and 10 dummy pixels 72 Is added to the top of the left pixel column 691c in FIG. In the following description, a pixel column having dummy pixels corresponding to the number of additional pixels added at the head is also referred to as an “added pixel column”.

  Here, if the line width correction shift amount and the standard shift amount are 0, the modulation operation is performed according to the first pixel (dummy pixel) of the corresponding added pixel column in the control of each light modulation element 461 described later. When the irradiated areas 92a to 92c are positions indicated by solid lines in FIG. 16, the first pixel 71 of the original pixel row 691a in the light modulation element 461 corresponding to the irradiated area 92a, that is, in FIG. The modulation operation according to the ninth pixel 71 from the top of the added pixel row on the right side is performed when the irradiation position is moved by a distance that is eight times the unit width T (as described above, the position relative to the irradiation region 92a). The correction shift amount is 0). Further, the modulation operation according to the first pixel 71 of the original pixel column 691b in the light modulation element 461 corresponding to the irradiation region 92b, that is, the sixth pixel 71 from the top of the added pixel column at the center in FIG. When the irradiation position is moved by a distance that is five times the unit width, a position correction shift amount that is (2/3) times the unit width T is further performed, and the original in the light modulation element 461 corresponding to the irradiation region 92c. In the modulation operation according to the first pixel 71 of the pixel row 691c of FIG. 20, that is, the eleventh pixel 71 from the top of the added pixel row on the left side in FIG. 20, the irradiation position is moved by a distance 10 times the unit width. Sometimes, it is performed with a position correction shift amount of (1/3) times the unit width T.

  In FIG. 16, irradiation areas 92a to 92c moved by distances of 8 times, 5 times and 10 times the unit width T from the position indicated by the solid line are indicated by two-dot chain lines, and the position indicated by the two-dot chain line. Irradiated regions 92b and 92c shifted by (2/3) times and (1/3) times the unit width T are indicated by broken lines. A dummy pixel 72 having an additional number of pixels is added to the head of the pixel row corresponding to each light modulation element 461, and the modulation operation for the light modulation element 461 is performed in accordance with the pixel row to which the dummy pixel 72 is added, and the position correction shift amount By performing the shift at a position shifted by only the same position in the main scanning direction on the substrate 9, the plurality of light modulation elements 461 draw the pixels at the same position in the column direction in the corresponding plurality of original pixel columns, respectively. Can be performed. As described above, the number of additional pixels and the position correction shift amount derived from the positional deviation amount are offset data for correcting the positional deviation of the plurality of irradiation regions irradiated with the light from the plurality of light modulation elements 461. Yes.

  Further, as shown in the second to fourth stages from the top in FIG. 21, dummy pixels (in the second to fourth stages from the top in FIG. 21, a plurality of dummy pixels are denoted by reference numeral 720 at the end of the pixel columns 691a to 691c. (Shown by one rectangle). At this time, a dummy pixel having a reference number of 8 is added to the end of the pixel column 691a in the pixel adding unit 631 corresponding to the irradiation region 92a, and an additional pixel from twice the reference number 8 in the pixel adding unit 631 corresponding to the irradiation region 92b. The number 11 of dummy pixels obtained by subtracting the number 5 is added to the end of the pixel row 691b, and the number 6 of dummy pixels obtained by subtracting the number of additional pixels 10 from twice the reference number 8 in the pixel addition unit 631 corresponding to the irradiation region 92c. Is added to the end of the pixel column 691c. As a result, the lengths of all the added pixel columns in which dummy pixels are added at the beginning and the end are equal.

  As described above, since the pixel column data 691 is input as run length data, the pixel adding unit 631 adds a run length indicating the pixel value indicating non-drawing and the number of additional pixels immediately before the first run length. Even after the last run length, an added pixel row can be easily obtained by adding a pixel value indicating non-drawing and a run length indicating the number of pixels obtained by subtracting the number of additional pixels from twice the reference number. Is generated. Actually, a plurality of run lengths included in the data of the added pixel column are sequentially output to the pixel column processing unit 632.

  In the pixel column processing unit 632, when the pixel values of the adjacent three pixel groups are 1, 2, and 1, respectively, as shown in the lowermost stage of FIG. 19, the first pixel value 1 (on the left side of FIG. 19) The pixel processing number for the change point between the white pixel group and the pixel group with the pixel value 2 parallel oblique lines is obtained as (+1) by referring to the pixel processing table 6301 of Table 3, and the pixel group of pixel value 2 The pixel value of the first pixel 71a is changed to 1, and the changing point moves (delays). Further, the number of processed pixels for the change point between the pixel group having the pixel value 2 and the next pixel group having the pixel value 1 (on the right side in FIG. 19) is obtained as 0, and the change point is not moved. As shown in Table 3, the pixel processing number is 0 between the pixels 71 having the same pixel value, and the pixel processing is not performed. Therefore, the pixel processing number affects only the change point. Become.

  Actually, in the pixel column processing unit 632, as shown in FIG. 22, the length of the run length (that is, the run length is calculated in the data of the pixel column (more precisely, the added pixel column) input as the run length data. The change point is moved by changing the number of pixels shown). In FIG. 22, one run length is illustrated as a rectangle (reference numerals 690a, 690b, and 690c are attached).

  In FIG. 22, a change point that is a position between a run length 690b denoted by “DATA (n)” and a run length 690c designated immediately by “DATA (n + 1)” (hereinafter referred to as “attention change point”). First, by referring to the pixel processing table 6301 using the pixel value of the run length 690b and the pixel value of the immediately subsequent run length 690c, the pixel processing number for the target change point is obtained. In the pixel column processing unit 632, correction conditions for the pixel column data shown in Table 5 are stored in advance. For example, a run length 690a and a run length 690b indicated as “DATA (n−1)” immediately before the run length 690b The pixel processing number (referred to as “the pixel processing number for DATA (n−1)” in Table 5) obtained for the change point between 0 is 0, and the pixel obtained for the target change point When the number of processes (referred to as “the number of pixel processes for DATA (n)” in Table 5) is also 0, the amount of change in the length of the run length 690b (“DATA (n) in Table 5”). "Actual processing with respect to") is set to zero.

  As shown in Table 5, the pixel processing number obtained for the change point between the run length 690a and the run length 690b is 0, and the pixel processing number obtained for the target change point is (+1). In some cases, the amount of change in the length of the run length 690b is set to (+1) (that is, the run length 690b is lengthened by one pixel). Further, when the pixel processing number obtained for the change point between the run length 690a and the run length 690b is (+1) and the pixel processing number obtained for the attention change point is 0, Since the run length 690a is extended by (+1), the change point of interest is delayed by one pixel, and therefore, the amount of change in the length of the run length 690b is set to (−1) (ie, the run length 690b is shortened by one pixel). Furthermore, when the number of pixel processes obtained for the change point between the run length 690a and the run length 690b is (+1), and the number of pixel processes obtained for the target change point is (+1). Since the run length 690a is extended by (+1), the target change point has already been delayed by one pixel, so the amount of change in the length of the run length 690b is set to zero.

  In the example shown at the bottom of FIG. 19, when the number of pixels (run length) of the center pixel group among the adjacent three pixel groups is 5, the first pixel (on the left side of FIG. 19) The number of processed pixels for the change point between the white pixel group with the value 1 and the pixel group with the parallel diagonal line with the pixel value 2 is (+1), and the next pixel group with the pixel value 2 (on the right side in FIG. 19). Since the number of processed pixels with respect to the change point between the pixel group of pixel value 1 is 0, the amount of change in the number of pixels (run length) of the pixel group of pixel value 2 is (−1), and the pixel The number of pixels in the value 2 pixel group is changed to 4.

  As described above, in the image recording apparatus 1, pixel column data (more precisely, data of an added pixel column) is input to the pixel column processing unit 632 as run-length data, and when moving each change point, By changing the length of the run length of the length data, the change point is easily moved, and the pixel column data is processed (step S18). Depending on the design of the pixel column processing unit 632, the data of the target image may be expressed in a format other than run-length data.

  In parallel with the processing of the pixel column data in the pixel column processing unit 632, the processed pixel column data (part thereof) is decoded by the output data generation unit 633 and divided for each number of pixels between base clocks. As described above, the conversion pixel data indicating the number of the pixel whose pixel value changes from the immediately preceding pixel and the pixel value (that is, the changed pixel number and the changed pixel value) of the pixel in the number of pixels between the base clocks. 692 is generated.

  For example, in the lowermost stage of FIG. 19, assuming that the pixel value of the pixel 71 a has been changed to 1 (white pixel) by the processing of the pixel column processing unit 632, the drawing corresponding to the base clock 303 a is performed. The changed pixel number and the changed pixel value of the converted pixel data 692 referred to are both set to 1 due to the absence of a change point in the four pixels 71 between the base clocks 303a and 303b (as described above, the change Even when there is no point, the changed pixel number is 1, and the changed pixel value is the same as the pixel value of the last pixel in the immediately preceding base clock period.) In addition, the changed pixel number and the changed pixel value of the converted pixel data 692 referred to when drawing corresponding to the base clock 303b are the first pixel (the first pixel among the four pixels 71 between the base clocks 303b and 303c. Due to the presence of a change point from the pixel value 1 to the pixel value 2 at the reference position), the change pixel number of the converted pixel data 692 and the post-change are set to 1 and 2, respectively, which are referred to when drawing corresponding to the base clock 303c. The pixel value is set to 1 due to the presence of a change point from the pixel value 2 to the pixel value 1 in the first pixel (first reference position) among the four pixels 71 between the base clocks 303c and 303d.

  Then, the converted pixel data 692 is output to the element driving element 61 in accordance with the base clock 303 generated every time the substrate 9 moves by a set distance corresponding to the number of pixels between base clocks (step S19). The element drive element 61 generates drive voltage data 301 and shift delay number data 302 from the converted pixel data 692 (step S20), and controls the light modulation element 461 to change the amount of light output from the light modulation element 461. A pattern is drawn on the substrate 9 while shifting the position (step S21).

  At this time, at the time of drawing corresponding to the base clock 303b in the uppermost stage in FIG. 19, the first pixel corresponds to the converted pixel data 692 in which the changed pixel number and the changed pixel value are 1 and 2, respectively. The reference position address (in this case, 0) is specified, and the correction shift amount is specified as (+ (1/6) T) using the immediately previous changed pixel value and the current changed pixel value. The Thereby, the shift delay number data 302 is obtained as a count number corresponding to the distance (+ (1/6) T), and the change of the target drive voltage as shown in the second stage from the top in FIG. 19 is realized. The changed target drive voltage is set to the second gradation drive voltage V2 based on the changed pixel value of the converted pixel data 692.

  Actually, as shown in the uppermost stage of FIG. 21, based on a start signal 306 generated in response to one base clock 303, a plurality of (all) light modulation elements 461 of the spatial light modulator 46 are transmitted. Modulation control is simultaneously started by a plurality of corresponding element drive elements 61.

  The generation of the conversion pixel data 692 in step S19 and the input to the element driving element 61 and the drawing of the pattern based on the conversion pixel data 692 in steps S20 and S21 record the entire image showing the target image on the substrate 9. (Step S22). When the entire target image is recorded, the movement of the substrate 9 in the main scanning direction is stopped, and the operation of recording an image on the substrate 9 is completed (step S23).

  If the rectangle indicated by reference numeral 93 at the bottom of FIG. 21 indicates an ideal range in the main scanning direction in which modulation control based on the original pixel row is to be performed, the (− Modulation based on all pixel columns (original pixel columns 691a to 691c) is generated by generating the start signal 306 at a position separated from the end on the Y side by a reference multiple of the unit width to the (−Y) side. Control is performed in the range of the rectangle 93 in the Y direction.

  Next, processing for determining the number of pixels between base clocks in step S12 will be described. FIG. 23 is a diagram showing the base clock 303 and the pixel columns. The upper part of FIG. 23 shows the base clock 303, the middle part shows the pixel line before the change point is moved, and the lower part shows the pixel line after the change point is moved (the same applies to FIG. 24 described later). In the middle and lower parts of FIG. 23, the position of the change point is indicated by an arrow labeled A2.

  As shown in the upper and middle stages of FIG. 23, when the number of pixels between the initial base clocks is set to 5, the data of the target image is each pixel group having the same pixel value continuously in each pixel column. (The logical minimum line width can be regarded as a width corresponding to 5 pixels), so that the transition of the output light quantity from the light modulation element 461 is the base. In the image recording apparatus 1 that can be performed only once in the clock period, an image can be appropriately recorded. In this case, suppose that FIG. When the process of delaying the change point by one pixel is performed in the processing of the pixel column data in step S18 of B, as shown in the lower part of FIG. 23, a pixel group having four pixels (pixels 71 with parallel oblique lines) is obtained. And two change points exist in the base clock period.

  Accordingly, in the main calculation unit 62, first, in the correction table of Table 1, the pixel value is calculated from the maximum value of the line width correction shift amount in the combination of a plurality of two pixel values in which each pixel value is the previous pixel value. A value obtained by subtracting the minimum value of the line width correction shift amount in a plurality of combinations in which is the current pixel value is obtained as the maximum thinning amount. Then, a value (physical minimum) obtained by subtracting the maximum thinning amount for all pixel values from the distance corresponding to the number of pixels between the initial base clocks (that is, the set distance corresponding to the number of pixels between the initial base clocks). The integer part of the value obtained by further dividing the line width by the unit width T is obtained as the pixel group minimum width.

  In the example of Table 1, the maximum value of the line width correction shift amount when the pixel value 1 is the previous pixel value is (+1/3) times the unit width T, and the pixel value 1 is the current pixel value. In this case, the minimum value of the line width correction shift amount is set to (−1/3) times the unit width T, and (−1/3) times the unit width T to (−1/3) times the unit width T. The subtracted value ((2/3) times the unit width T) is the maximum value for all pixel values of the maximum thinning amount. Then, a value obtained by subtracting the maximum thinning amount from 5 times the unit width T corresponding to the number of pixels between the initial base clocks ((13/3) times the unit width T) is further obtained as the unit width T. The integer part 4 of the divided value is obtained as the pixel group minimum width. Then, as shown in the upper part of FIG. 24, the number of pixels between base clocks is determined as 4, which is smaller than the number of pixels between initial base clocks. Thereby, in the processing of the pixel column data, a process of delaying the change point by one pixel is performed, and as shown in the lower part of FIG. 24, a pixel group having four pixels (a set of pixels 71 with parallel diagonal lines). Even when is generated, it is prevented that two change points exist in the base clock period.

  As described above, in the main calculation unit 62, in the processed pixel column, the number of pixels of the smallest pixel group having the smallest number of pixels among the plurality of pixel groups each having the same pixel value continuously in the column direction is When it is smaller than the number of pixels between the initial base clocks, a process for reducing the set distance to a distance corresponding to the number of pixels of the minimum pixel group is performed. Then, as described above, the output data generation unit 633 generates the conversion pixel data 692 with the number of pixels between the base clocks being four, so that there are no two change points in the base clock period, and the light modulation element Pattern drawing by the modulation of 461 is performed.

  In the image recording apparatus 1 of FIG. 1, the substrate holding unit 3 is actually moved with respect to the light irradiation unit 4 in the (−Y) direction by the holding unit moving mechanism 2 (that is, the irradiation region on the substrate 9 is ( (Relative movement in the + Y) direction), the plurality of light modulation elements 461 draw a plurality of pixel columns included in the target image, and the plurality of irradiation regions on the substrate 9 are the (+ Y) side ends of the substrate 9. When the drawing of the plurality of pixel columns is completed, the substrate holding unit 3 moves in the X direction perpendicular to the Y direction and along the substrate 9, and then opposite to the previous drawing of the plurality of pixel columns. By moving in the direction ((+ Y) direction), the plurality of light modulation elements 461 perform drawing of a plurality of other pixel columns included in the target image.

  At this time, when drawing a plurality of pixel rows by moving the substrate holding unit 3 in the (−Y) direction, the irradiation region positioned on the front side ((+ Y) side) in the relative movement direction from the reference position is the substrate holding unit. When the plurality of other pixel columns are drawn by the movement in the (+ Y) direction of 3, the pixel holding position is located behind the reference position in the relative movement direction ((+ Y) side). Accordingly, the number of additional pixels and the position correction shift amount are different. Therefore, in the image recording apparatus 1, when a plurality of pixel columns are drawn by the movement of the substrate holding unit 3 in the (−Y) direction and the other plurality of pixels by the movement of the substrate holding unit 3 in the (+ Y) direction. At the time of drawing a column, a different number of additional pixels, a pixel processing table 6301, and a modified shift amount table 6171 are used for each light modulation element 461, so that both the forward and backward movements of the substrate holder 3 can be performed. Thus, an image is recorded on the substrate 9 with high accuracy.

  As described above, in the image recording apparatus 1 in FIG. 1, the amount of positional deviation in the main scanning direction between the reference position and each irradiation region, and α times the unit width (where α is a positive integer) The number of dummy pixels increased or decreased from the reference number by α corresponding to the difference of less than the unit width is added to the head of the pixel column corresponding to the irradiation region to generate an added pixel column, and the difference is determined to be the irradiation Obtained as the position correction shift amount for the region. Then, the light modulation elements 461 are controlled by the control unit 6 based on the added pixel row and the position correction shift amount in synchronization with the holding unit moving mechanism 2. As a result, it is possible to easily realize the correction of the positional deviation in the scanning direction that greatly exceeds the distance (unit width) corresponding to one pixel in the plurality of irradiation regions. As a result, each component of the image recording apparatus can be corrected. The mechanical adjustment is performed extremely strictly, so that the positions of the plurality of irradiation areas in the main scanning direction are not substantially matched (that is, the required accuracy of the mechanical adjustment is relaxed) or by the warp of the base plate Even when it is impossible to match the positions of the plurality of irradiation areas in the main scanning direction, a highly accurate image can be easily recorded on the substrate 9.

  Further, the image recording apparatus 1 generates a correction table indicating the line width correction shift amount and the position correction shift amount for each light modulation element 461, and the total shift amount for each combination of two pixel values in the correction table. Is obtained by substantially shifting the transition position of the output light amount from the light modulation element 461 in order to correct the drawing deviation of the pixel group at each change point of the added pixel row corresponding to each light modulation element 461. The amount of shift to be performed (shift amount before correction) is obtained. When the shift amount for each change point exceeds the unit width during actual image recording, the change point moves in the column direction by the number of pixels in the integer part of the value obtained by dividing the shift amount by the unit width. As described above, the pixel value of the pixel included in the added pixel column is changed, and the shift amount corresponding to the change point is corrected to a value corresponding to the decimal part. The light modulation element 461 is controlled based on the shift amount. Thereby, when an image is recorded on the substrate 9, it is possible to record the image with high accuracy while shifting the transition position of the output light amount from the light modulation element 461 beyond the distance corresponding to one pixel.

  Further, in the image recording apparatus 1, a plurality of pixel processing tables 6301 indicating the movement amount of the change point for each combination of two pixel values, and a shift in which the correction table value is corrected for each combination of two pixel values A plurality of correction shift amount tables 6171 indicating amounts (correction shift amounts) are generated from the plurality of correction tables by the main calculation unit 62. Then, by referring to the corresponding pixel processing table 6301 using the combination of two pixel values at each change point of the added pixel column in the pixel column processing unit 632, the movement amount of the change point is acquired and the change point is obtained. By referring to the corresponding correction shift amount table 6171 using a combination of two pixel values at each change point of the added pixel column in the correction shift amount acquisition unit 618 A process of acquiring the correction shift amount at the change point is performed. Thereby, in the image recording apparatus 1, when an image is recorded on the substrate 9, the shift of the transition position exceeding the distance corresponding to one pixel can be easily realized.

  Here, in the main arithmetic unit 62, if the positional deviation amount with respect to each light modulation element 461 is handled as it is as the position correction shift amount, the range that the total shift amount can take is wide, and the range that the pixel processing number can take is wide. Become. As a result, the combination of “the number of pixel processing for DATA (n−1)” and “the number of pixel processing for DATA (n)” in the correction condition of the pixel column data in Table 5 significantly increases. The size of the correction condition increases, and the logic for realizing the function of the pixel column processing unit 632 becomes complicated (larger).

  On the other hand, in the actual main calculation unit 62, the positional deviation amount is divided into the number of additional pixels and the positional correction shift amount, and the positional correction shift amount is made smaller than the distance corresponding to one pixel (that is, unit width). This prevents the combination of “the number of pixel processings for DATA (n−1)” and “the number of pixel processings for DATA (n)” from significantly increasing in the correction condition of the pixel column data. The size of the data correction condition can be reduced, and the logic for realizing the function of the pixel column processing unit 632 can be simplified (downsized).

  As described above, in the image recording apparatus 1, since one element driving element 61 and one FPGA control element 63 are provided for each of a plurality (all) of light modulation elements 461, in the present embodiment, A set of memories 630 in the plurality of FPGA control elements 63 is regarded as a first table storage unit that stores a plurality of pixel processing tables 6301 respectively corresponding to the plurality of light modulation elements 461, and the memory 617 in the plurality of element driving elements 61. Is a second table storage unit that stores a plurality of correction shift amount tables 6171 respectively corresponding to the plurality of light modulation elements 461. A set of pixel column processing units 632 in the plurality of FPGA control elements 63 is regarded as an image change unit that acquires the movement amount of each change point and moves the change point in the column direction. A set of the corrected shift amount acquisition unit 618 in FIG. 5 is regarded as a shift amount acquisition unit that acquires a corrected shift amount for each change point.

  FIG. 25 is a diagram showing a configuration of an image recording apparatus 1a according to the second embodiment of the present invention. The image recording apparatus 1a includes one optical head 41a that emits light for image recording and a holding drum 70 that is a holding unit that holds a recording medium 9a on which an image is recorded on an outer surface. An image is recorded on the recording medium 9a by drawing by light irradiation (exposure) from the optical head 41a. As the recording medium 9a, for example, a printing plate, a film for forming a printing plate, or the like is used. Note that a photosensitive drum for plateless printing may be used as the holding drum 70. In this case, the recording medium 9a corresponds to the surface of the photosensitive drum, and the holding drum 70 integrally holds the recording medium 9a. Can be considered.

  The holding drum 70 is rotated around the central axis of the cylindrical surface by the motor 81, whereby the optical head 41a irradiates the recording medium 9a in the main scanning direction (light from a plurality of light modulation elements described later). It moves at a relatively constant speed (in a direction perpendicular to the arrangement direction of the plurality of irradiation areas). The optical head 41a can be moved in the sub-scanning direction (perpendicular to the main scanning direction) parallel to the rotation axis of the holding drum 70 by the motor 82 and the ball screw 83, and the position of the optical head 41a is an encoder (not shown). Is detected. As described above, the moving mechanism including the motors 81 and 82 and the ball screw 83 causes the outer surface of the holding drum 70 and the recording medium 9a to move in the main scanning direction at a constant speed with respect to the optical head 41a having the spatial light modulator. It relatively moves and also moves relatively in the sub-scanning direction intersecting the main scanning direction. The motors 81 and 82 and the encoder are connected to the control unit 6a, and the control unit 6a controls the emission of the signal light from the spatial light modulators in the motors 81 and 82 and the optical head 41a, thereby recording on the holding drum 70. Image recording by light is performed on the medium 9a.

  FIG. 26 is a diagram showing an outline of the internal configuration of the optical head 41a. In the optical head 41a, a light source 43a, which is a bar-type semiconductor laser having a plurality of light emitting points in a row, and a spatial light modulator 46 having a plurality of diffraction grating type light modulation elements arranged in a row are arranged. Then, the light from the light source 43a is guided to the spatial light modulator 46 via the lens 471 (actually constituted by a condensing lens, a cylindrical lens, etc.) and the prism 472. At this time, the light from the light source 43a is converted into linear light (light having a linear cross section) and is irradiated onto a plurality of light modulation elements arranged in a line.

  Each light modulation element of the spatial light modulator 46 is controlled by the modulator control unit 60 (see FIG. 25) of the control unit 6a having the same configuration as that of the first embodiment. In FIG. 26, the element driving element 61 of the modulator control unit 60 is shown as a block. The zero-order light emitted from the light modulation element is returned to the prism 472, and the first-order diffracted light is guided in a direction different from that of the prism 472. In order to prevent stray light from being generated, the first-order diffracted light is shielded by a light shielding unit (not shown).

  The zero-order light from each light modulation element is reflected by the prism 472 and guided to the recording medium 9a outside the optical head 41a via the zoom lens 473 so that the images of the plurality of light modulation elements are arranged in the sub-scanning direction. Formed on the recording medium 9a. The magnification of the zoom lens 473 is variable by a zoom lens drive motor 474, whereby the resolution of the recorded image is changed.

  Also in the image recording apparatus 1a of FIG. 25, an image is recorded on the recording medium 9a by the same operation as the image recording apparatus 1 of FIG. At this time, the difference α between the amount of positional deviation with respect to each light modulation element and the unit width α times (where α is a positive integer) is less than the unit width, and the difference is determined by the light modulation element. Is obtained as a position correction shift amount for. As a result, an appropriate number (additional pixels) of dummy pixels is added to each pixel row, and drawing in the main scanning direction is started with a plurality of light modulation elements using a position correction shift amount smaller than the unit width. The positions can be matched.

  Further, in the image recording apparatus 1a, by obtaining a total shift amount for each combination of two pixel values in a correction table indicating a line width correction shift amount and a position correction shift amount, a pixel column corresponding to the light modulation element. With respect to each change point, a shift amount for shifting the transition position of the output light amount from the light modulation element in order to correct the drawing deviation of the pixel group is substantially obtained, and the shift amount corresponds to one pixel. When the width of the region on 9a in the main scanning direction (that is, unit width) is exceeded, the change point moves so that the change point moves by the number of pixels in the integer part of the value obtained by dividing the shift amount by the unit width. And the shift amount corresponding to the change point is corrected to a value corresponding to the decimal part. Thereby, when recording an image on the recording medium 9a, it is possible to shift the transition position of the output light amount from the light modulation element beyond the distance corresponding to one pixel, and it is possible to record the image with high accuracy. It becomes.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In the example of FIG. 18, the example in which the distance at which the target drive voltage is set to the second gradation drive voltage V2 corresponding to the pixel value 2 in the light modulation element 461 is shortened (see the fourth stage from the top in FIG. 27) has been described. However, as shown in the third row from the top in FIG. 27, the line width correction shift amount in the correction table may be determined so that the distance at which the target drive voltage is set to the second gradation drive voltage V2 becomes long. . Further, in the image recording apparatuses 1 and 1a, in addition to shifting the transition position of the light modulation element 461 to the front side in the traveling direction of the irradiation position (see the fifth stage from the top in FIG. 27), as shown in the bottom stage in FIG. In addition, the irradiation position may be shifted to the rear side in the traveling direction.

  Even in such a case, the standard shift amount, which is the shift amount when the correction of the drawing deviation is not performed, is set to ½ times the unit width T, and the substrate 9 or the recording medium 9a corresponding to one pixel. A value obtained by increasing / decreasing the distance (in the above embodiment, the line width correction shift amount and the position correction shift amount) based on the drawing deviation of the pixel group from the half of the width in the main scanning direction of the upper region (according to pixel processing) ) By setting the shift amount before correction, the transition position of the output light amount of the light modulation element 461 can be easily moved to both sides in the main scanning direction, and as a result, the image can be recorded with high accuracy. It becomes.

  In the image recording apparatuses 1 and 1a accompanied by the pixel column processing in the pixel column processing unit 632, if the number of pixels between the initial base clocks is set to 1, FIG. In the process of step S12 of A, the number of pixels between base clocks cannot be determined to be smaller than the number of pixels between initial base clocks, and the presence of a plurality of change points during the base clock period cannot be prevented. Therefore, in the image recording apparatuses 1 and 1a that involve processing of the pixel rows, the number of pixels between the initial base clocks must be 4 or 2, as shown in the middle and lower stages of FIG. 28, that is, 2 or more. It becomes.

  In the first and second embodiments, by using the pixel processing table 6301 and the correction shift amount table 6171, it is possible to easily shift the transition position exceeding the distance corresponding to one pixel. When the shift amount of each change point exceeds a distance corresponding to one pixel, the change point moves so that the change point moves by the number of pixels in the integer part of the value obtained by dividing the shift amount by the distance. If the pixel value is changed and the shift amount corresponding to the change point is corrected to a value corresponding to the decimal part, image recording is performed without using the pixel processing table 6301 and the corrected shift amount table 6171. It may be broken.

  In addition, when there is no need to consider the line width correction shift amount, such as variations in line width drawn in the plurality of light modulation elements 461 are within an allowable range, the pixel processing table is used in the image recording apparatuses 1 and 1a. The generation of 6301 and the correction shift amount table 6171 (and the shift amount excess detection unit 621, the table generation unit 622, the pixel column processing unit 632, and the correction shift amount acquisition unit 618) may be omitted. In this case, the position correction shift amount less than the unit width acquired together with the number of additional pixels from the position shift amount is stored in the memory 617 of the element driving element 61 instead of the correction shift amount table 6171, and two pixels at each change point are stored. Regardless of the combination of values, a value obtained by adding the reference position address and the position correction shift amount is obtained as the shift delay number, and the transition position of the output light amount is shifted. In such an image recording apparatus, the number of pixels between the base clocks can be set to 1 (that is, the logical minimum line width is set to a width corresponding to 1 pixel). The amount is the number of shift delays.

  In the spatial light modulator 46 in the above embodiment, switching between activation and deactivation is possible only for all the light modulation elements 461 as a unit, that is, driving to only some of the light modulation elements 461. Therefore, the lengths of the added pixel columns corresponding to all of the light modulation elements 461 are equal. However, depending on the design of the spatial light modulator, a spatial light modulator is configured by a plurality of element groups each of which is two or more light modulation elements 461, and activation and deactivation are performed for each element group. Switching may be possible. In this case, in the main calculation unit 62, the lengths of the corresponding added pixel columns are made equal in each of the plurality of element groups.

  As described above, in the image recording apparatus, a plurality of (all) light modulation elements 461 of the spatial light modulator are configured by at least one element group, each of which is two or more light modulation elements 461. By adding a dummy pixel to the end of each pixel row, the length of the added pixel row corresponding to each element group is made equal, so that an image can be appropriately recorded on the substrate 9 It becomes. Note that the light modulation elements 461 included in each element group do not necessarily have to be continuously arranged. For example, every other light modulation element 461 is included in one element group, and the remaining light modulation elements 461 are included in the other element groups. The light modulation element 461 may be included in another element group. Of course, in the image recording apparatus, a spatial light modulator that can be switched between activation and deactivation for each light modulation element 461 may be used.

  In the image recording apparatuses 1 and 1a, the signal light for drawing does not necessarily have to be zero-order light, and the first-order diffracted light may be signal light. Further, the relative positional relationship between the flexible ribbon 461a and the fixed ribbon 461b that is not bent differs from the above embodiment, and the light modulation element that emits zero-order light when the flexible ribbon 461a is bent. 461 may be used. Even in these cases, appropriate image recording is realized by shifting the operation timing of the light modulation element 461.

  The flexible ribbon 461a and the fixed ribbon 461b do not need to be in a ribbon shape in a strict sense as long as they can be regarded as a belt-like reflecting surface. For example, the block-shaped upper surface may serve as a reflecting surface of the fixed ribbon. Further, the emission of the 0th-order light or the emission of the 1st-order diffracted light may be performed by bending both ribbon pairs included in the light modulation element 461 by different amounts.

  The light modulation element 461 is not limited to the diffraction grating type, and may be a liquid crystal shutter, for example. Furthermore, the light modulation element 461 is not limited to one that reflects light. For example, a laser array may serve as the light modulation element 461. Even in these cases, appropriate image recording is realized by correcting the positional deviations of the plurality of irradiation regions respectively corresponding to the plurality of elements.

  In addition, a two-dimensional spatial light modulator may be employed. In this case, the correction for the plurality of light modulation elements in the above embodiment is applied to each one-dimensional array of light modulation elements.

  In the image recording apparatuses 1 and 1a of FIGS. 1 and 25, the number of additional pixels and the position correction shift amount are obtained from the amount of displacement with respect to each light modulation element 461, and the shift is performed while moving the change point where the total shift amount exceeds the unit width. The arithmetic unit for correcting the amount is realized by the main arithmetic unit 62, the plurality of FPGA control elements 63, and the plurality of element driving elements 61. However, when it is not necessary to record an image at high speed, the function of the arithmetic unit is It may be realized only by calculation in the main calculation unit 62 (in software).

  The plurality of irradiation areas on the substrate 9 and the recording medium 9a may be moved by other methods as long as they can move relative to the substrate 9 and the recording medium 9a in the scanning direction intersecting the arrangement of the irradiation areas. Good. The recording medium for holding image information (may be in a shape other than a plate or sheet) is coated with a photosensitive material such as a printed wiring board or a semiconductor substrate, or is photosensitive. It may be another material that has or may be a material that reacts to heat by light irradiation.

DESCRIPTION OF SYMBOLS 1,1a Image recording apparatus 2 Holding | maintenance part moving mechanism 3 Substrate holding | maintenance part 6,6a Control part 9 Substrate 9a Recording medium 46 Spatial light modulator 61 Element drive element 62 Main operation part 63 FPGA control element 71,71a Pixel 72,720 Dummy Pixel 81 Motor 92a to 92c Irradiation area 460 Base plate 461 Light modulation element 461a Flexible ribbon 461b Fixed ribbon 617,630 Memory 618 Correction shift amount acquisition unit 632 Pixel column processing unit 691a to 691c Pixel column 6171 Correction shift amount table 6301 Pixel processing table

Claims (6)

An image recording apparatus for recording an image on a recording medium by light irradiation,
A light modulator having a plurality of light modulation elements;
Lights from the plurality of light modulation elements are respectively irradiated, and a plurality of irradiation regions arranged approximately linearly on the recording medium are relative to the recording medium in a scanning direction intersecting the array of the plurality of irradiation regions. A moving mechanism that moves automatically,
A plurality of pixels arranged in a column direction corresponding to the scanning direction in a target image to be recorded on a recording medium are defined as a pixel column, and the plurality of light modulation elements are respectively associated with a plurality of pixel columns included in the target image. The reference position and each irradiation area fixed relative to the plurality of irradiation areas on the recording medium with the width in the scanning direction of the area on the recording medium corresponding to one pixel as a unit width The number of non-drawings that are increased or decreased from the predetermined number by α, where the difference between the amount of positional deviation in the scanning direction and α times the unit width (where α is a positive integer) is less than the unit width A calculation unit that adds a dummy pixel indicating a pixel column corresponding to each irradiation region to generate an added pixel column, and acquires the difference as a position correction shift amount for each irradiation region;
A control unit that controls each light modulation element based on the added pixel row and the position correction shift amount in synchronization with the moving mechanism;
An image recording apparatus comprising: The image recording apparatus according to claim 1,
Each pixel column of the target image is a set of a plurality of pixel groups each having the same pixel value continuously in the column direction,
The arithmetic unit shifts the transition position of the output light amount from the light modulation element for each change point that is a position between two adjacent pixel groups in each added pixel column in order to correct the drawing deviation of the pixel group. The shift amount to be obtained is calculated based on the position correction shift amount and the line width correction shift amount for correcting the drawing width of the pixel group, and the number of pixels in the integer part of the value obtained by dividing the shift amount by the unit width. The pixel value of the pixel included in each added pixel column is changed so that each change point moves in the column direction, and the shift amount corresponding to each change point is equivalent to the decimal part of the value Modify the value to
The image recording apparatus, wherein the control unit controls each of the light modulation elements based on each of the added pixel columns after the change and the corrected shift amount. The image recording apparatus according to claim 2,
In the calculation unit, for each change point, the shift amount before correction is obtained based on a combination of pixel values of the two adjacent pixel groups,
The computing unit is
A first table storage unit that stores a pixel processing table indicating a moving amount of a change point with respect to each of a plurality of combinations of two pixel values for each of the light modulation elements;
By referring to the pixel processing table using a combination of two pixel values at each change point of each added pixel column, a movement amount of each change point is obtained, and each change point is set in the column direction. An image changer to move to,
A second table storage unit that stores a correction shift amount table indicating a shift amount after correction for each of the plurality of combinations of two pixel values for each of the light modulation elements;
A shift amount acquisition unit that acquires the corrected shift amount for each change point by referring to the correction shift amount table using a combination of two pixel values at each change point of each added pixel column When,
An image recording apparatus comprising: The image recording apparatus according to claim 3,
A holding unit for holding the recording medium;
The holding unit moves relative to the optical modulator in the scanning direction by the moving mechanism, so that the plurality of light modulation elements perform drawing of the plurality of pixel columns included in the target image and the holding. The portion is relatively moved in a direction perpendicular to the scanning direction and along the recording medium, and then is relatively moved in a direction opposite to the drawing time of the plurality of pixel columns, whereby the plurality of light modulation elements are moved to the target image. Draw multiple other pixel columns included,
Image recording, wherein different pixel processing tables and modified shift amount tables are used for the respective light modulation elements at the time of drawing the plurality of pixel columns and at the time of drawing the other plurality of pixel columns. apparatus. The image recording apparatus according to any one of claims 1 to 4,
The plurality of light modulation elements are each composed of at least one element group that is two or more light modulation elements, and switching between activation and deactivation is possible for each element group,
The arithmetic unit adds a dummy pixel to the end of the pixel column corresponding to each irradiation region, so that the length of the corresponding added pixel column is equalized in each of the at least one element group. An image recording apparatus. An image recording apparatus according to any one of claims 1 to 5,
Each of the plurality of light modulation elements is a diffraction grating type light modulation element having at least one ribbon pair, and the plurality of light modulation elements are arranged in one direction on the same base plate. The image recording apparatus, wherein the amount of displacement in the scanning direction between the reference position and each irradiation region is caused by warpage of the base plate in the normal direction.

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