JPH06406B2 - Optical drawing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention irradiates a spot pattern with light, projects the obtained light spots on a photosensitive material, and continuously moves them relative to a ruled line. The present invention relates to an optical drawing device such as a phototypesetting machine or an optical plotter designed to draw.

[Prior Art and Problems] Conventionally, in order to draw a line such as a ruled line with a phototypesetting machine or the like, recording is performed by relatively moving the photoconductor and the light spot while projecting the light spot on the photoconductor. The spot pattern used to create the light spot used at this time was generally rectangular or square, as indicated by 11 in FIG. This is because the conventional apparatus was mainly configured to process only straight lines in the X and Y directions, but it was also for reproducing the start and end line ends of the ruled line at right angles.

Further, in the rectangular spot pattern, the rectangular light spot obtained by irradiating light on the rectangular spot pattern is arranged in two directions (that is, X
Direction, Y direction) to draw a line, the lengths of the sides parallel to the traveling direction of the pattern are the same, so that the amount of light received by the photosensitive member is substantially uniform over the entire area.
The image exposed on the photosensitive material has an advantage that it becomes a uniform line without density unevenness.

Therefore, if a plurality of such patterns 11 are prepared in advance according to the thickness of the ruled line, the ruled line having the required thickness can be drawn by selectively using them.

By the way, in such a rectangular pattern 11, in the X direction,
It is suitable for drawing straight lines in the Y direction, but not suitable for drawing curves. FIG. 1 is a view showing a state in which a rectangular light spot is drawn in a curve by changing the direction in which the light spot advances little by little.
In the figure, the alternate long and short dash line indicates the traveling direction of the pattern 11,
Reference numerals 11a, 11b, and 11c show patterns in which the light spots formed by this pattern move. Pattern 1
If 1 moves in parallel to its side, its line width is W ₁ and W ₂ , but when moving diagonally, the thickness of the line changes to W ₃ as shown by the dotted line in the figure. (W
₃ > W ₁ ).

Therefore, it is conceivable to use a circular spot pattern 21 as shown in FIG. 2A so that a line can be drawn with the same width in any direction. However, this spot pattern 21
Of exposure dose when moving to draw a straight line or curve 22
As shown in FIG. 2B, the exposure amount in the central portion of the line becomes significantly larger than the exposure amount in the peripheral portion when viewed from the direction in which the pattern advances (the direction of the arrow in the figure). The contour is blurred.

When the brightness of the light beam that illuminates the pattern is increased,
The exposure amount at the center becomes strong and a phenomenon of fogging occurs, and the line becomes thicker than the diameter W of the pattern.

Furthermore, in order to change the thickness of the ruled line, it is necessary to prepare a plurality of types in which the diameter W of the pattern is changed as in the case of the rectangular spot pattern. If the diameter of the light changes, the amount of light passing through also changes. If the moving speed of the light spot is constant, the exposure amount is proportional to the area of the pattern.Therefore, if the light amount is adjusted to a pattern having a small diameter, the light amount becomes excessive in a pattern having a large diameter, and the density of the line to be exposed rises excessively. The fog phenomenon occurs. That is, if the size of the pattern is changed, the intensity of the light beam must be changed accordingly.

Therefore, it may be considered that the spot pattern itself has an exposure amount adjusting function. As such, for example, as disclosed in Japanese Examined Patent Publication No. 47-39886, there is known an annular spot pattern in which the central portion of the pattern is shielded so as not to transmit light. In this annular pattern, the exposure amount can be made constant by making the width of the annular opening band constant regardless of the diameter of the circle.

FIG. 3 shows how ruled lines are drawn by such an annular pattern. At the start point and the end point 31 of the shaded line, only half the exposure amount can be obtained as compared with the intermediate portion 32 shown by the double shaded line. Therefore, it is unavoidable that the density at the end of the line becomes low and the image becomes visually blurred.

A method of adjusting the light quantity by providing a filter having an appropriate transmittance at the center of the circular spot pattern shown in FIG. 2 is also conceivable. If the diameter of the pattern is large, a filter with a low transmittance is provided to reduce the exposure amount.If the diameter of the pattern is small, a filter with a high transmittance is provided to increase the light amount. The quality of ruled lines can be standardized. However, providing a filter having a different transmittance depending on the diameter of the circular spot pattern is a difficult process and is not preferable in manufacturing.

[Object of the Invention] The present invention is an optical drawing device that draws a line on a photosensitive material by projecting a light spot on the photosensitive material and moving the both relatively, and a ruled line of a constant quality is recorded on the photosensitive material. It is an object of the present invention to provide an optical drawing device.

A second object is to provide an optical drawing device having a spot pattern that allows a predetermined work to be performed under a constant condition without adjusting the light amount according to the size of the spot pattern to be used. .

Furthermore, the third purpose is to adjust the width of the circular ring according to the thickness of the ruled line or to provide a filter with different density,
An object is to provide an optical drawing apparatus having a spot pattern that can be easily manufactured by a simple method.

In order to achieve such an object, the present invention irradiates a spot pattern with light to project a light spot on a photoconductor, and continuously moves the light spot to draw a ruled line. It is characterized in that the light spots are formed by irregularly distributing light dots in a predetermined circular area.

[Embodiment of the Invention] FIG. 4 shows the principle of a spot pattern used in the present invention. In the spot pattern 41, a large number of light-transmissive dots 42 are arranged uniformly and irregularly. There is.
(B) The shaded portion indicated by 43 in the figure shows the distribution 43 of the exposure amount when the pattern 41 is irradiated.

When such a pattern 41 is irradiated with light, the light passes through the translucent dots 42 to expose the photosensitive material. A ruled line can be drawn by moving the photoconductor and the light spot relatively. Therefore, if the dots are randomly distributed (number and size) according to the diameter of the spot pattern, the exposure amount can be kept constant regardless of the thickness of the ruled line. That is, a small number of translucent dots per unit area may be irregularly distributed in a spot pattern with a large diameter, and a large number of translucent dots per unit area may be irregularly distributed in a spot pattern with a small diameter. The same.)

By drawing a ruled line with such a spot pattern, for example, it is possible to suppress the peak lower than the peak of the exposure distribution 22 of FIG. 2B, as shown by the distribution 43 of FIG. The phenomenon of fogging can be greatly reduced. Further, at the starting point and the ending point of the ruled line, the exposure amount can be evenly distributed over the entire pattern as compared with the annular pattern illustrated in FIG. 3, so that the decrease in density can be suppressed.

FIGS. 4C and 4D explain the reason why the dots are arranged irregularly. If the dots are regularly arranged as shown in (c) and the light spots obtained thereby are moved in the direction of the arrow, as shown in (d), depending on the position where the dots are arranged. The difference in the amount of exposure occurs in the exposure distribution 44, resulting in unevenness in the exposure distribution 44.

Therefore, in the present invention, no matter how the light spot moves,
In order to create a ruled line without unevenness in density, dots are arranged irregularly as shown in (a). Such dot arrangement can be easily obtained by a random number table or the like.

FIG. 5 shows a case where the starting end portion of the line is started to be drawn by the pattern 52 in which the translucent dots 51 are uniformly and irregularly distributed, and the hatched portion 53 is exposed by the pattern 52 and becomes a ruled line. It is a part. In this embodiment, FIG. 2 and FIG.
Although the problems described in FIGS. 4 (c) and 4 (c) and (d) are solved, unevenness occurs in the shape of the end portion depending on the presence or absence of the dot arranged at the leftmost end (the rightmost end at the end portion). Sisters,
The roughness when the dots are arranged is directly exposed on the photosensitive material.

FIG. 6 shows an embodiment which solves this drawback. This is configured such that the dots 62 in the peripheral portion of the pattern 61 are distributed with high density, and the dots are coarser in the central portion. This allows the quality at the beginning and end of the line to approach that of a circular pattern, for example. Also, as shown in FIG. 6 (b), the exposure amount at the center can be suppressed, so that the boundary of the ruled line can be made clear.

FIG. 7 shows an embodiment which is a further development of that shown in FIG. 6, in which dots 72 are densely arranged on the outer periphery of the pattern 71 so that density unevenness due to the roughness of the dots can be ignored, and at the center. The dots 73 are irregularly roughened compared to the peripheral portion.
Are distributed. The regular dots 72 arranged in the peripheral portion of the pattern can be operated to align the quality of the end faces at the beginning and end of the line, that is, to eliminate the density unevenness due to the roughness of the dots. Prevent the visual confirmation of the presence or absence of.

Therefore, as shown in FIG. 8, a ring 81 having a narrow width is provided at the outermost peripheral portion, and dots 82 regularly arranged are arranged inside thereof.
If the pattern 84 in which the dots 83 arranged irregularly in the central portion are distributed, a ruled line having a smoother contour can be obtained.

In each of the above examples, the dots arranged in the predetermined circular area are translucent, but conversely, when the light shielding dots are arranged in the translucent circular area, the exposure amount on the spot pattern itself is increased. It is possible to have an adjusting function.

FIG. 9 illustrates an apparatus for drawing ruled lines on a photosensitive material by using a phototypesetting machine as an example, using a dial containing a plurality of spot patterns having different diameters as described above.
Reference numeral 91 is a light source, and light is condensed by a condenser lens 92, and an optical path is changed by a prism or a mirror 93. A plurality of spot patterns as described above are accommodated in a dial of 94 together with characters and symbols. A desired pattern is selected by moving the dial in the XY directions and set at the optical axis position. The set pattern is irradiated with the light from the light source, passes through the main lens 95 and the deforming lens 96, undergoes optical path conversion by the prisms 97 and 98, and forms an image on the photosensitive material 99. A shutter 100 controls exposure. Further, the light spot is moved by the horizontal movement of the prism 98 in the drawing and the rotation of the drum holding the photosensitive material 99. Although this movement is performed by the pulse motor 101 or the like, various control devices 102 for constant speed movement may be publicly known.

In order to draw a straight line on the photosensitive material with such an apparatus, the coordinates of the start point and the end point or the length of the ruled line are input from an input unit (not shown), and an instruction to start the exposure releases the shutter 100. The prism 98 or the drum holding the photosensitive material 99 operates to move the light spot according to the set spot pattern. The light spot at this time is affected by the magnification of the optical system such as the main lens 95 and the deformable lens 96, but the desired straight line can be recorded arbitrarily.

When drawing a curve, if the radius r designating the size of the curve and the coordinates of the start and end points are input, the shutter 100 operates in the same way as in the case of a straight line, and the prism 98 and the photosensitive member 99 are operated.
Can be simultaneously driven to reproduce a curve having a curvature corresponding to the designated radius r on the photosensitive material.

Of course, it is obvious that the effect of the present invention is greater when the diameter of the spot pattern is larger than when it is small. Further, as described above, since the dial 94 contains not only the spot pattern but also the character symbols,
If they are used together and exposed on the photosensitive material, it is possible to create a printed material with characters and ruled lines together as specified.

Furthermore, if a spot pattern is used not only with a phototypesetting machine having an optical system as shown in FIG. 9 but also with an arbitrary optical plotter, it is possible to record ruled lines on the photosensitive material in the same manner.

EFFECTS OF THE INVENTION As described above, the present invention uses a spot pattern in which translucent dots or light-shielding dots are randomly distributed in a predetermined circular area. Contours can be drawn sharply with a constant quality on the photosensitive material without being restricted by the width and with uniform density. Since the necessary light amount adjustment is also performed on the spot pattern, it is possible to proceed with the work of different ruled lines under certain conditions without adjusting the light amount from the light source according to the thickness of the ruled line. Also, instead of providing a filter with an analog density change in the spot pattern, it is possible to handle it with dots of a binary image, so it does not take time to produce, and stable quality can be produced. .

[Brief description of drawings]

FIG. 1 shows an example of the implementation of the present invention.
FIG. 3 is a conventional explanatory diagram, FIG. 4 is a diagram for explaining the principle of the spot pattern used in the present invention, FIG. 5, FIG. 6, FIG.
FIG. 8 is a diagram for explaining an embodiment of a spot pattern used in the present invention, and FIG. 9 is a diagram showing an example of a phototypesetting machine. 11 spot pattern 21 spot pattern 41 spot pattern 42 translucent dot 52 spot pattern 61 spot pattern 72 regular dot 73 irregular dot 81 circular ring 94 dial 99 photosensitive material

Claims (3)

[Claims] 1. An optical drawing apparatus for irradiating a spot pattern with light to project a light spot on a photosensitive material and continuously moving the light spot and the photosensitive material to draw a ruled line, wherein the spot pattern is a light shield. An optical drawing device using a light beam, characterized in that the transparent dots or the transparent dots are irregularly distributed in a predetermined circular area. 2. The spot pattern is such that light-transmitting dots (or light-shielding dots) in a peripheral portion of the predetermined circular region are distributed at a higher density (or a lower density) than the central portion of the region. The optical drawing device according to claim 1, wherein the optical drawing device is configured as follows. 3. The spot pattern is such that the dots in the peripheral portion of the predetermined circular region are evenly distributed so that density unevenness due to dot roughness can be ignored, and the dots in the central portion are irregular compared to the peripheral portion. The optical drawing device according to claim (1), characterized in that the optical drawing device is configured to be distributed in the following manner.