JP7225756B2 - Inspection device, inspection method - Google Patents

Description

The present invention relates to an inspection apparatus and an inspection method for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged within the surface of the sheet.

A diffractive optical element (DOE) has attracted attention as an optical element for shaping the light from the light source of various sensors into the size, shape, etc. of a target irradiation area.
This applies the diffraction phenomenon when light passes through a place where materials with different refractive indices are arranged periodically. DOEs are designed primarily for light of a single wavelength, but theoretically they can shape light into almost any shape. In addition, the DOE can control the uniformity of the light distribution within the irradiation area. Such characteristics of the DOE are advantageous in terms of high efficiency by suppressing irradiation to unnecessary areas, miniaturization of the apparatus by reducing the number of light sources, and the like.
In addition, DOEs can be used with both parallel light sources such as lasers and diffuse light sources such as LEDs, and can be applied to a wide range of wavelengths from ultraviolet light to visible light and infrared light.

A DOE requires microfabrication on the order of nm, and in particular, in order to diffract long-wavelength light, it is necessary to form a microscopic shape with a high aspect ratio. Therefore, an electron beam lithography technique using an electron beam can be used for manufacturing the DOE. Furthermore, in order to improve productivity, a substrate made of quartz or the like produced by electron beam lithography is used as an original plate, and a mold is formed on a resin, whereby a large number of duplicate substrates can be produced and productivity can be improved.
In addition, by mounting multiple optical elements of the DOE on a single substrate, a large number of optical elements can be manufactured from a single substrate.
An optical element such as a DOE mounted on multiple surfaces on a substrate is individualized by a method such as dicing or punching, and mounted on an electrical component such as a holder.

As described above, since the DOE shapes light with a fine shape, even a slight change in shape tends to cause a large change in optical characteristics. Therefore, it is desirable to inspect whether or not the optical characteristics after manufacturing are appropriate for DOEs used in sensors and the like that require particularly high detection accuracy.

Goniometers and integrating spheres are measuring instruments that measure the luminous intensity distribution (light distribution) in each direction in the far-field space through light sources and optical elements.
Since the goniometer performs measurement by moving or rotating the light-receiving sensor or the light source, the measurement takes time. On the other hand, the integrating sphere can measure all at once, but the luminous intensity distribution is unknown and only the integrated value can be measured.
Patent Document 1 proposes an inspection apparatus for a hologram body that projects light onto a screen or a camera and measures the light distribution all at once.

However, recent sensors are becoming smaller, and DOEs used in sensors are also becoming smaller. Therefore, when each DOE is set in an inspection apparatus for measurement, the work may be difficult, or the DOE may not be properly set in the inspection apparatus, resulting in an inability to perform a correct inspection.

Further, as described above, in the case of a diffractive optical element sheet in which multiple DOE optical elements are mounted on a single substrate, the size of the diffractive optical element sheet is larger than that of each DOE. However, there is no established method for inspecting individual DOEs with multiple faces, and a simple and highly accurate inspection method has been desired.

Japanese Patent No. 4598915

SUMMARY OF THE INVENTION An object of the present invention is to provide an inspection apparatus and an inspection method that can easily and highly accurately inspect a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged within the sheet surface.

The present invention solves the above problems by means of the following solutions. In order to facilitate understanding, reference numerals corresponding to the embodiments of the present invention are used for explanation, but the present invention is not limited to these.

A first invention is an inspection apparatus (1, 201) for inspecting a diffractive optical element sheet (500) in which a plurality of unit diffractive optical elements (501) are arranged in the sheet surface, the diffractive optical element sheet A holding part (10) which holds (500) and is movably provided, and a driving part ( 20), a light projecting unit (30) for projecting inspection light onto the diffractive optical element sheet (500) held by the holding unit (10), and the inspection transmitted through the diffractive optical element sheet (500). an imaging unit (40) for imaging light; ) and an imaging control section (80) for sequentially imaging the inspection light by controlling the driving section (20).

A second invention is the inspection apparatus (1, 201) according to the first invention, wherein the diffractive optical element sheet ( An inspection apparatus (1, 201) characterized by comprising an optical system (43) for deflecting the optical path of the inspection light transmitted through the inspection light (500).

A third invention is the inspection apparatus (1, 201) according to the first invention, further comprising a screen (50) onto which the inspection light transmitted through the diffractive optical element sheet (500) is projected, wherein the photographing A unit (40) is an inspection apparatus (1, 201) characterized by capturing an image of the inspection light projected onto the screen (50).

A fourth invention is the inspection apparatus (1, 201) according to any one of the first invention to the third invention, wherein the holding part (10) is a sheet surface of the diffractive optical element sheet (500). The inspection device (1, 201) is characterized in that the diffractive optical element sheet (500) is held so that the direction is along the vertical direction.

A fifth invention is the inspection apparatus (1, 201) according to any one of the first invention to the fourth invention, wherein at least the light projecting section (30), the holding section (10), and the photographing section (40) with a distance measuring unit (37) capable of measuring any distance between them at a plurality of points; and an adjusting unit (11, 31, 41, 51) capable of adjusting an angle of intersection between the optical axis of the inspection light and the sheet surface of the diffractive optical element sheet (500). (1,201).

A sixth aspect of the invention is the inspection apparatus (1, 201) according to any one of the first to fourth aspects of the invention, wherein a A mark (M) provided on a part of the held diffractive optical element sheet (500) is provided, and the photographing unit (40) directly passes through the mark (M) or passes through the mark (M). At least the intersection angle between the optical axis of the inspection light and the imaging surface of the imaging unit (40), and the optical axis of the inspection light and the diffractive optical element sheet (500) The inspection apparatus (1, 201) further comprises adjusting units (11, 31, 41, 51) capable of adjusting the crossing angles of the sheet surfaces of the two.

A seventh invention is the inspection apparatus (1, 201) according to any one of the first invention to the sixth invention, wherein the light projecting section (30) comprises a laser light source (33) and a collimator lens. (34), and a variable aperture (35), and further comprising a light source rotating section (36) capable of rotating at least the laser light source (33) about the optical axis of the laser light. An inspection device (1, 201).

According to an eighth invention, in the inspection apparatus (1, 201) according to any one of the first invention to the seventh invention, the imaging control unit (80) moves and stops the holding unit (10). and are repeated, and an image is taken by the photographing unit (40) while the holding unit (10) is stopped.

In a ninth invention based on the inspection apparatus (1, 201) according to any one of the first invention to the eighth invention, the imaging control section (80) comprises the unit diffractive optical elements arranged in at least one direction. The inspection apparatus (1, 201) is characterized in that the photographing of (501) is performed by the photographing unit (40) while the holding unit (10) continues to move.

In a tenth aspect of the invention, in the inspection apparatus (1, 201) according to the eighth aspect or the ninth aspect, the imaging control unit (80) uses preset imposition information and alignment information to , calculating the position of the unit diffractive optical element (501) and determining the timing of photographing.

According to an eleventh invention, in the inspection apparatus (1, 201) according to the tenth invention when citing the ninth invention, the imaging control section (80) controls the inspection light to be the unit diffractive optical element ( 501) is projected onto the diffractive optical element region (502) in which the pattern is formed, the inspection device (1, 201) is characterized in that the imaging is continued or the imaging is performed multiple times. be.

According to a twelfth invention, in the inspection apparatus (1, 201) according to any one of the first invention to the eleventh invention, based on information obtained by imaging by the imaging unit (40), the An inspection apparatus (1, 201) comprising an evaluation section (90) for evaluating light distribution characteristics of a unit diffractive optical element (501).

In a thirteenth invention based on the inspection apparatus (1, 201) according to the twelfth invention, the unit diffractive optical element (501) divides the incident light into a plurality of beams and distributes the light to a plurality of different positions. characterized in that the evaluation unit (90) quantifies at least one of brightness, size, and position at each position of the projected image of the split light. is an inspection device (1, 201).

According to a fourteenth invention, in the inspection apparatus (1, 201) according to the thirteenth invention, the evaluation unit (90) quantifies the uniformity of all projected images of the split light. An inspection device (1, 201) characterized.

A fifteenth aspect of the invention is an inspection apparatus (301) for inspecting a singulated unit diffractive optical element (501), comprising: a holder (310) for holding the unit diffractive optical element (501); a light projecting unit (330) for projecting inspection light onto the unit diffractive optical element (501) held by the unit (310); and an imaging unit for photographing the inspection light transmitted through the unit diffractive optical element (501). (340); driving units (321, 322) for moving at least one of the holding unit (310), the light projecting unit (330), and the photographing unit (340); and at least the unit diffractive optical element ( 501), the imaging unit (340) and the driving units (321, 322) are controlled so that the imaging unit (340) performs imaging with the inspection light projected thereon, and the inspection light and an imaging control unit (380) that performs imaging.

In a sixteenth invention based on the inspection apparatus (301) according to the fifteenth invention, the holding part (310) is a unit diffractive optical element (501) viewed from a direction along the optical axis of the inspection light. An inspection device (301) that restricts the rotation of the unit diffractive optical element (501) around the optical axis of the inspection light by holding at least part of the outer diameter shape.

A seventeenth invention is the inspection apparatus (301) according to any one of the first invention to the sixteenth invention, wherein the unit diffractive optical element (501) and the light projecting section (330) Relative position changing units (311a, 312) capable of changing the positional relationship in a rotational direction about the optical axis of the inspection light are provided, and the imaging control unit (380) controls the unit diffractive optical element (501) and the light projecting unit (311a, 312). An inspection apparatus (301) characterized by performing imaging in a plurality of states with different relative positional relationships with a unit (330).

An eighteenth invention is the inspection apparatus (301) according to any one of the first invention to the fifteenth invention, wherein the photographing control unit (380) detects noise light other than a predetermined light distribution in the photographing result. An inspection characterized by controlling the driving units (321, 322) to change the position at which the inspection light is irradiated onto the unit diffractive optical element (501) and performing imaging again when the inspection light is detected. A device (301).

A nineteenth invention is an inspection method for inspecting a diffractive optical element sheet (500) in which a plurality of unit diffractive optical elements (501) are arranged in the sheet plane, wherein an inspection apparatus (1, 201) comprises: A holding part (10) which holds a diffractive optical element sheet (500) and is movably provided, and inspection light is projected onto the diffractive optical element sheet (500) held by the holding part (10). and a photographing unit (40) for photographing the inspection light transmitted through the diffractive optical element sheet (500), wherein the holding unit (10) is held by the diffractive optical element sheet (500). ), and the imaging unit (40) performs imaging while the inspection light is projected onto at least the unit diffractive optical element (501). a photographing control unit (80) for controlling the photographing unit (40) and the driving unit (20) and sequentially photographing the inspection light, wherein the photographing control unit (80) controls the holding unit The inspection method is characterized in that the movement and stop of (10) are repeated, and imaging is performed by the photographing unit (40) while the holding unit (10) is stopped.

In a twentieth aspect based on the nineteenth aspect, in the inspection method according to the nineteenth aspect, the photographing control section (80) controls the holding section (10) to photograph the unit diffractive optical elements (501) arranged in at least one direction. The inspection method is characterized in that the photographing unit (40) performs photographing while continuing the movement of the body.

In a twenty-first invention based on the inspection method according to the nineteenth invention or the twentieth invention, the photographing control section (80) uses preset imposition information and alignment information to determine the unit diffraction optics. This inspection method is characterized by calculating the position of the element (501) and determining the timing of photographing.

In a twenty-second invention based on the inspection method according to the twenty-first invention when citing the twentieth invention, the imaging control unit (80) controls the inspection light so that the pattern of the unit diffractive optical element (501) is The inspection method is characterized by continuing photographing or photographing a plurality of times while being projected onto the formed diffractive optical element region (502).

In a twenty-third aspect of the invention, in the inspection method according to any one of the nineteenth aspect to the twenty-second aspect, the evaluation section (90), based on the information obtained by the imaging section (40) , and evaluating the light distribution characteristics of the unit diffractive optical element (501).

In a twenty-fourth aspect of the invention, in the inspection method according to the twenty-third aspect of the invention, the unit diffractive optical element (501) divides the incident light into a plurality of beams and distributes the light beams to a plurality of different positions, An inspection method characterized in that the evaluation unit (90) quantifies at least one of brightness, size, and position at each position of the projection image of the split light. be.

According to a twenty-fifth invention, in the inspection method according to the twenty-fourth invention, the evaluation unit (90) quantifies the uniformity of all projected images of the split light. is.

A twenty-sixth aspect of the invention is an inspection method for inspecting a singulated unit diffractive optical element (501), wherein an inspection apparatus (301) includes a holding part (310) for holding the unit diffractive optical element (501). a light projecting section (330) for projecting inspection light onto the unit diffractive optical element (501) held by the holding section (310); A photographing unit (340) for photographing, and a driving unit (321, 322) for moving at least one of the holding unit (310), the light projecting unit (330), and the photographing unit (340), The photographing control unit (380) controls the photographing unit (340) and the and controlling driving units (321, 322).

In a twenty-seventh aspect, in the inspection method according to any one of the nineteenth to twenty-sixth aspects, the imaging control unit (380) detects noise light other than a predetermined light distribution in the imaging result. (3) is an inspection method characterized by controlling the drive units (321, 322) to change the position at which the inspection light is irradiated onto the unit diffractive optical element (501), and performing imaging again. .

According to the present invention, it is possible to provide an inspection apparatus and an inspection method that can easily and highly accurately inspect a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged within the sheet surface.

1 shows a first embodiment of an inspection device according to the invention; FIG. 4 is an enlarged view of the holding portion 10. FIG. 3 is a side view of the light projecting section 30; FIG. 3 is a front view of a light projecting section 30; FIG. 3 is a block diagram showing a control configuration of the inspection device 1; FIG. FIG. 10 is a diagram for explaining a situation at the time of photographing; FIG. 10 is a diagram showing a state in which an area other than the center of the chip 501 is also photographed. 5 is a diagram showing an example of a photographed image obtained by photographing an image projected on a screen 50 through a chip 501 of the present embodiment by the photographing unit 40. FIG. FIG. 10 is a diagram schematically illustrating an intermediate process of performing arithmetic processing on one of spots P1 to P9 within an evaluation unit; FIG. 9 is a diagram showing an example of the calculation result of the brightness evaluation value side by side in correspondence with the arrangement in FIG. 8 ; 1 shows a first embodiment of an inspection device according to the invention; FIG. Fig. 3 shows a third embodiment of an inspection device according to the invention; It is a perspective view which shows only the principal part of the inspection apparatus of 3rd Embodiment. FIG. 10 is a perspective view showing the holding part in more detail; 3 is a block diagram showing a control configuration of an inspection device 301; FIG. 5 is a diagram showing a state in which inspection light is properly projected onto a chip 501; FIG. 5 is a diagram showing an example of a projected image (image captured by an imaging unit) projected from the chip 501 in a state in which inspection light is appropriately projected onto the chip 501; FIG. FIG. 5 is a diagram showing a state in which inspection light is projected at a position shifted from an appropriate position with respect to a chip 501; 5 is a diagram showing an example of a projection image (image captured by an imaging unit) projected from the chip 501 in a state in which inspection light is projected onto the chip 501 at a position shifted from an appropriate position; FIG. It is the figure which expanded the central spot P part, and showed how the unnecessary light R generate|occur|produced. FIG. 4 is a diagram for explaining multiple times of imaging and handling of the data; FIG. 4 is a diagram showing an example in which a mark M is provided on a part of the holding portion 10; 5 is a diagram showing an example in which a mark M is provided on a part of the diffractive optical element sheet 500; FIG. FIG. 10 is a diagram showing an example of a movable block capable of holding multiple chips;

BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a first embodiment of an inspection apparatus according to the present invention.
In addition, each figure shown below including FIG. 1 is a schematic diagram, and the size and shape of each part are shown exaggerated appropriately for easy understanding.
Also, in the following description, specific numerical values, shapes, materials, and the like are shown and described, but these can be changed as appropriate.
In this specification, terms specifying shapes and geometrical conditions, such as parallel and orthogonal terms, have strict meanings, as well as similar optical functions to the extent that they can be regarded as parallel or orthogonal. It also includes states with errors.
In this specification, terms such as plate, sheet, and film are used, and as a general usage, they are used in the order of thickness, plate, sheet, and film. I use it in my book as well. However, since there is no technical meaning in such proper use, these words can be replaced as appropriate.
In this specification, the sheet surface refers to a surface of each sheet that is in the plane direction of the sheet when the sheet is viewed as a whole. It should be noted that the plate surface and the film surface are assumed to be the same.
In the present invention, the term "transparent" refers to a material that transmits at least the light of the wavelength used. For example, even if a material does not transmit visible light, if it transmits infrared light, it is treated as transparent when used for infrared applications.

The inspection apparatus 1 is an apparatus for inspecting a diffractive optical element sheet 500 in which a plurality of unit diffractive optical elements (chips 501) are arranged within the sheet surface.
The inspection apparatus 1 includes a holding section 10 , a driving section 20 , a light projecting section 30 , an imaging section 40 and a screen 50 .

The holding section 10 detachably holds the diffractive optical element sheet 500 . The holding part 10 is provided so as to be movable in the X-axis direction and the Y-axis direction in FIG. 1 by the driving part 20 .
FIG. 2 is an enlarged view of the holding portion 10. As shown in FIG.
The holding part 10 has an opening 13, and holds the diffractive optical element sheet 500 at the position where the opening 13 is provided by, for example, a compression spring 12 as shown in FIG. Here, the holding section 10 holds the diffractive optical element sheet 500 so that the sheet surface of the diffractive optical element sheet 500 is oriented along the vertical direction. As a result, it is possible to prevent the diffractive optical element sheet 500 from bending due to its own weight, and it is possible to perform accurate inspection without adverse effects due to the bending of the diffractive optical element sheet 500 .

Here, the diffractive optical element sheet 500 will be described. A diffractive optical element sheet 500 to be inspected when set to the inspection apparatus of the present embodiment is a so-called multi-surface sheet in which a plurality of chips (unit diffractive optical elements) 501 are arranged before being cut off. (or film, plate). The chip 501 is used by being attached to, for example, a light source part of a sensor or the like in an individualized state. A diffractive optical element region 502 is formed substantially in the center of each chip 501 . This diffractive optical element region 502 is formed with a fine concave-convex pattern, and has the function of diffracting, deflecting, and emitting light of a predetermined wavelength to shape the light. Function. In FIG. 2, the chips 501 are arranged in three rows and three columns on the diffractive optical element sheet 500 for ease of understanding and visibility, but in reality, more chips are arranged. It is

Further, the holding portion 10 is attached to the drive portion 20 via the holding portion adjustment portion 11 . Since the holding portion adjusting portion 11 supports the holding portion 10 rotatably around two axes around the X axis and the Y axis, the direction (inclination) of the sheet surface of the diffractive optical element sheet 500 attached to the holding portion 10 can be changed. ) can be adjusted. The holding portion adjustment portion 11 of the present embodiment includes a drive source that operates under the control of an adjustment control portion 70, which will be described later.

The drive unit 20 incorporates a drive source and is a moving stage (orthogonal robot) capable of plane movement in two orthogonal directions, and moves the holding unit 10 in a direction along the surface of the diffractive optical element sheet 500. .

The light projecting section 30 projects inspection light onto the diffractive optical element sheet 500 held by the holding section 10 .
FIG. 3 is a side view of the light projecting section 30. FIG.
FIG. 4 is a front view of the light projecting section 30. FIG.
The light projecting section 30 is attached to a base 32 via a light projecting section adjustment section 31 . The light projecting unit adjustment unit 31 supports the light projecting unit 30 so as to be rotatable about two axes around the X axis and the Y axis, so the direction (inclination) of the inspection light emitted by the light projecting unit 30 can be adjusted. is. The light projection unit adjustment unit 31 of this embodiment includes a drive source that operates under the control of an adjustment control unit 70 described later.
The light projecting section 30 also includes a laser light source 33 , a collimator lens 34 , a variable diaphragm 35 and a light source rotating section 36 .

The laser light source 33 emits laser light having a wavelength diffracted by the diffraction grating formed in the diffractive optical element region 502 of the diffractive optical element sheet 500 .

The collimator lens 34 is a lens for correcting the laser light emitted by the laser light source 33 into parallel light.

The variable diaphragm 35 is a diaphragm whose aperture diameter can be varied. The variable aperture 35 can restrict the laser light that has passed through the collimator lens 34 to adjust the light amount, and can also block the light that spreads out without being corrected by the collimator lens 34 .

The light source rotator 36 attaches the laser light source 33, the collimator lens 34, and the variable aperture 35 to the frame 38 in a rotatable state around the optical axis of the laser light. The reason why the laser light source 33 is rotatable is that the polarization direction of the laser light emitted by the laser light source 33 can be adjusted in a predetermined direction. When polarized light is applied to a diffraction grating, the state of emitted light (light distribution direction and light intensity) may change depending on the polarization state (polarization direction) of the light. , the light source rotation unit 36 is effective.

Furthermore, the light projecting section 30 is provided with a distance measuring section 37 . The distance measuring units 37 are provided at three locations on the frame 38 of the light projecting unit 30 at intervals. A laser displacement meter, for example, can be used for the distance measuring unit 37 . The distance measuring unit 37 measures the distance between the light projecting unit 30 and the holding unit 10, the distance between the light projecting unit 30 and the screen 50, and the distance between the light projecting unit 30 and the photographing unit 40. can be done. Since these distances can be measured at three spaced points, the relative inclinations of the light projecting section 30, the holding section 10, the screen 50, and the photographing section 40 can be known, and the relationship between them can be determined. can be adjusted to proper placement. This adjustment will be described later.

Furthermore, the light projecting section 30 includes a filter holding section 39 . Various optical filters can be arranged in the filter holding portion 39 as required. For example, a polarizing filter can be arranged on the filter holding portion 39 . By arranging the polarizing filter in the filter holding portion 39, the polarization state of the light projected by the light projecting portion 30 can be changed.

The photographing unit 40 is a camera that photographs the inspection light that has passed through the diffractive optical element sheet 500 . In this embodiment, the photographing unit 40 photographs the inspection light that is projected onto the screen 50 and passes through the screen 50 from the side opposite to the light projecting unit 30 . The photographing unit 40 is configured by a camera having an imaging device capable of photographing the light projected by the light projecting unit 30 . For example, when the diffractive optical element sheet 500 to be inspected is for infrared light, the light projecting section 30 projects infrared light. In that case, the photographing unit 40 is configured to include an imaging device capable of photographing infrared light.
Also, the imaging unit 40 may be provided with a bandpass filter (not shown). By arranging the band-pass filter, unnecessary wavelength bands can be cut depending on the wavelength of the laser used, and the influence of light other than the inspection light in the environment where the inspection apparatus 1 is installed can be suppressed.
Also, the photographing unit 40 is attached to a pedestal 42 via a photographing unit adjustment unit 41 . The photographing unit adjusting unit 41 supports the photographing unit 40 so as to be rotatable about two axes around the X-axis and the Y-axis, so that the orientation (inclination) of the optical axis of the photographing unit 40 can be adjusted. The imaging unit adjustment unit 41 of the present embodiment includes a drive source that operates under the control of an adjustment control unit 70, which will be described later.

The screen 50 is a translucent transmissive screen onto which inspection light transmitted through the diffractive optical element sheet 500 is projected. The screen 50 is attached to a pedestal 52 via a screen adjusting section 51 . Since the screen adjustment unit 51 supports the screen 50 rotatably about two axes around the X axis and the Y axis, the orientation (inclination) of the projection surface of the screen 50 can be adjusted. The screen adjustment unit 51 of the present embodiment includes a driving source that operates under the control of an adjustment control unit 70, which will be described later.

The base 60 is a base portion of the inspection apparatus 1 . In FIG. 1, the base 60 is shown as a single plate, but it may be configured by a plurality of members, or may be configured in a frame shape by combining rectangular lumbers such as aluminum. The driving unit 20, the light projecting unit 30, the photographing unit 40, and the screen 50 are arranged along the direction in which inspection light is projected from the light projecting unit 30, that is, along the Z-axis direction in FIG. It is attached to a base 60 via a rail 61, and its position can be adjusted along the Z-axis direction in FIG.

FIG. 5 is a block diagram showing the control configuration of the inspection apparatus 1. As shown in FIG.
In addition to the holding unit 10, the driving unit 20, the light projecting unit 30, the imaging unit 40, the screen 50, and the like, the inspection apparatus 1 includes an adjustment control unit 70, an imaging control unit 80, and and an evaluation unit 90 .

The adjustment control section 70 drives the holding section adjustment section 11 , the light projection section adjustment section 31 , the photographing section adjustment section 41 , and the screen adjustment section 51 based on the measurement result of the distance measurement section 37 . Then, the adjustment control unit 70 controls the intersection angle between the optical axis of the inspection light and the screen surface of the screen 50, the intersection angle between the optical axis of the inspection light and the imaging surface of the imaging unit 40, and the optical axis of the inspection light and diffraction. Automatic adjustment is performed so that the intersection angles with the sheet surface of the optical element sheet 500 are all right angles.

The imaging control unit 80 controls the imaging unit 40 and the driving unit 20 so that the imaging unit 40 performs imaging while the inspection light is projected onto the chip 501, and sequentially performs imaging with the inspection light. Here, the term "sequential" also means a continuous operation, and may be a form in which the holding unit 10 is temporarily stopped and the photographing is performed, or a form in which the photographing is continuously performed while the holding unit 10 continues to move. There may be. Further, here, the meaning of the phrase "taking pictures sequentially" is not limited to taking still pictures, but also includes taking moving pictures. Moving image shooting is also a series of still image shooting, and in the present invention, there is no need to separate them.
For example, in a certain photographing mode, the photographing control unit 80 repeats moving and stopping of the holding unit 10 so that the photographing unit 40 can photograph while the holding unit 10 is stopped.
FIG. 6 is a diagram for explaining the situation at the time of photographing.
For example, the photographing control unit 80 performs control so that photographing is performed in the state shown in FIG. After that, as described above, the imaging control unit 80 repeats the movement and stopping of the holding unit 10 and successively images other adjacent chips 501 .
Here, the imaging control unit 80 calculates the position of the chip 501 using preset imposition information and alignment information, and determines the timing of imaging.

As another imaging mode, the imaging control unit 80 can perform imaging by the imaging unit 40 while continuing the movement of the holding unit 10 for imaging of the chips 501 arranged in at least one direction (for example, the X-axis direction). At this time, only the center of the chip 501 may be photographed as shown in FIG.
FIG. 7 is a diagram showing a state in which an area other than the center of the chip 501 is also photographed.
For example, while the inspection light is projected onto the diffraction optical element region 502 in which the pattern of the chip 501 is formed, the imaging control unit 80 may continue imaging or may perform imaging multiple times. . That is, when the diffractive optical element sheet 500 moves leftward in FIG. Shooting may be performed at the position of S2 and the position of the projected light spot S3.
Alternatively, while the inspection light is being projected onto the diffractive optical element region 502, photographing (exposure) may be continued. In a diffractive optical element (DOE), even if the position of the incident light (inspection light) changes, the image projected from the diffractive optical element does not change, so inspection by such continuous exposure is possible. .

The evaluation unit 90 evaluates the light distribution characteristics of the chip 501 based on the image information obtained by the photographing unit 40 . Regarding the specific contents of the evaluation performed by the evaluation unit 90, depending on what kind of light distribution characteristics the chip 501 of the diffractive optical element sheet 500 to be inspected is seeking, an appropriate optimum algorithm is used as an evaluation method. good. Below, an example of the evaluation method by the evaluation part 90 is shown.

FIG. 8 is a diagram showing an example of a captured image captured by the imaging unit 40 and projected onto the screen 50 through the chip 501 of the present embodiment.
The chip 501 of this embodiment splits incident light into a plurality of beams and distributes the split beams to a plurality of different positions. In the example of FIG. 8, the light is branched into nine spots P1 to P9 arranged in three rows and three rows, and distributed so as to be arranged in a square shape. In this example, it is assumed that the light distribution state is such that the brightness of each spot is uniform and the brightness difference is small.

FIG. 9 is a diagram schematically illustrating an intermediate process in which one of the spots P1 to P9 is subjected to arithmetic processing within the evaluation section.
The evaluation unit 90 extracts the position where the brightness is maximum for each of the spots P1 to P9, and regards the range from the position of the maximum brightness to the range where the brightness is reduced by a predetermined amount as the range of the spots P1 to P9. handle. In FIG. 9, the white position is the maximum luminance position, and the luminance decreases as the hatching increases. The area outside the area shown in FIG. 9 is an area where the brightness is lower than the predetermined amount, and is outside the spot area. Therefore, the evaluation unit 90 treats the illustrated range as a spot area. Here, as for the predetermined amount when determining the range in which the luminance is lowered by a predetermined amount from the maximum luminance position, various methods such as half the maximum luminance, 80%, etc. are conceivable. A luminance area below the value obtained by dividing the luminance by the natural logarithm e (value of 1/e) was assumed to be outside the spot area.

After extracting the spot area as described above, the evaluation unit 90 calculates a brightness evaluation value for evaluating the brightness of the spot area. Regarding this brightness evaluation value, for example, the position of the maximum brightness may be used, or an integrated value may be used, and various methods are conceivable. In the present embodiment, the evaluation unit 90 uses the average luminance value within the spot area as the brightness evaluation value. By using the average value, it is possible to make an evaluation close to human appearance.

FIG. 10 is a diagram showing an example of the calculation result of the lightness evaluation value side by side in correspondence with the arrangement in FIG. 8 . It should be noted that the example of the brightness evaluation value shown in FIG. 10 is shown as a dimensionless value expressed as a ratio (%) to 100, which is the target value.
The evaluation unit 90 further calculates a uniformity evaluation value for evaluating the uniformity from the obtained lightness evaluation values of all the spots (9 spots in the above example) using the following formula.
Uniformity evaluation value = (maximum brightness evaluation value - minimum brightness evaluation value) / (maximum brightness evaluation value + minimum brightness evaluation value)
This formula is the same as the arithmetic formula for obtaining a contrast value for evaluating contrast in general. However, in this embodiment, uniformity is desirable, so the smaller the uniformity evaluation value, the better, and it is 0 in the best condition. Thus, the evaluation unit 90 quantifies the uniformity of all projected images of the split light.
The evaluation unit 90 obtains this uniformity evaluation value, and if it is lower than the threshold, it determines that the product is good, and if it is higher than the threshold, it determines that the product is defective. The position of the chip 501 is stored or output for notification. For the evaluation value of the evaluation unit 90, in addition to the uniformity evaluation value, for example, a numerical value for evaluating brightness may be added to the evaluation items, and furthermore, the position of the spot may be within the allowable range. You may add a numerical value to evaluate whether or not

As described above, according to the inspection apparatus 1 of the first embodiment, it is possible to easily and highly accurately inspect a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged within the sheet plane. is.

(Second embodiment)
FIG. 11 is a diagram showing a second embodiment of an inspection device according to the present invention.
The inspection apparatus 201 of the second embodiment does not include the screen 50 of the first embodiment. It is different from the first embodiment in that a meter lens 43 is provided, but other parts have the same configuration as the first embodiment. Therefore, portions that perform the same functions as those of the above-described first embodiment are denoted by the same reference numerals, and overlapping descriptions are appropriately omitted.

In the inspection apparatus 201 of the second embodiment, the detection light transmitted through the diffractive optical element sheet 500 is directly captured by the imaging unit 40 without going through a screen. By not providing a screen, the influence of scattering and regular reflection of the inspection light on the screen can be suppressed, and more accurate inspection can be performed.
Also, the imaging unit 40 is provided with a collimator lens 43 . As a result, it is possible to accurately deliver the inspection light to the imageable area of the small imaging device.

(Third Embodiment)
FIG. 12 is a diagram showing a third embodiment of an inspection device according to the present invention.
FIG. 13 is a perspective view showing only the main parts of the inspection device of the third embodiment. In FIG. 13, the frame structure 302 and the like for holding each part are omitted.
In the inspection apparatuses 1 and 201 of the first and second embodiments, an example of inspecting each chip 501 in the form of the diffractive optical element sheet 500 has been described. On the other hand, the inspection apparatus 301 of the third embodiment is configured to inspect the state of the chip 501 after being singulated. 201 is different.
The inspection apparatus 301 of the third embodiment includes a holding section 310 , a first driving section 321 , a second driving section 322 , a light projecting section 330 , an imaging section 340 and an optical path defining section 350 .

The holding unit 310 is configured to hold one individualized chip 501 .
FIG. 14 is a perspective view showing the holding part in more detail.
The holding portion 310 includes a body portion 311 and a movable block portion 312 .

The main body portion 311 has a substantially plate shape and is fixed to the frame structure 302 so that the plate surface thereof is substantially horizontal. The body portion 311 has a counterbore portion 311a formed substantially in the center thereof in a square shape when viewed from a direction along an optical axis O of a laser beam projected by a light projecting portion 330 described later, that is, a direction substantially along the vertical direction. have.
A through hole 311b is opened in the direction along the optical axis O at the center of the counterbore 311a.

The movable block portion 312 is formed in a substantially square shape when viewed from the direction along the optical axis O, and is fitted to the outer shape of the counterbore portion 311a so as not to generate a substantially gap. Although not shown, the movable block portion 312 and the counterbore portion 311a are fitted with an appropriate gap, and the movable block portion 312 is brought into contact with the counterbore portion 311a in one direction for positioning. A biasing mechanism using force members or screws may be provided.
The movable block portion 312 has a chip mounting counterbore portion 312a formed in the center thereof so as to have an external shape (square in this embodiment) in which the chip 501 can be mounted with substantially no gap when viewed from the direction along the optical axis O. there is The individualized chip 501 is mounted and held in the chip mounting counterbore portion 312a. In addition, a groove shape or the like may be formed around the chip mounting counterbore portion 312a for facilitating attachment and detachment of the mounted chip 501. FIG.
A through hole 312b is opened in the direction along the optical axis O at the center of the chip mounting counterbore 312a.
In addition, the movable block portion 312 has two knob portions 312c projecting in the direction along the optical axis O. As shown in FIG.

With such a configuration of the holding portion 310, it is possible to easily change the mounting direction of the movable block portion 312 with respect to the counterbore portion 311a. can function as a relative position changer that can be changed in the rotational direction around the optical axis O.

The first driving unit 321 is provided between the light projecting unit 330 and the frame structure 302, and moves the light projecting unit 330 to control the direction and position of the optical axis O of the laser beam projected by the light projecting unit 330. is changed (adjusted). In the present embodiment, the first driving section 321 has a configuration in which a gonio stage, a rotating stage, and an XY stage are combined, and can perform adjustment operations with a high degree of freedom.

The second driving unit 322 is provided between the imaging unit 340 and the frame structure 302, and moves the imaging unit 340 so that the optical axis O of the laser beam projected by the light projecting unit 330 is correctly directed to the imaging unit 340. Driving is performed to change (adjust) the position of the photographing unit 340 so that the position of the photographing unit 340 is reached. In this embodiment, the second driving section 322 has a configuration in which a gonio stage, a rotating stage, and an XY stage are combined, and can perform adjustment operations with a high degree of freedom.
Both the first driving section 321 and the second driving section 322 incorporate an electrically driven driving source, and the driving thereof is controlled by an imaging control section 380 which will be described later.
Note that the stages for driving provided in the first driving section 321 and the second driving section 322 do not include all of the above-described stages, and may be partially omitted depending on the device configuration, or may be manually operated.

The light projecting section 330 is a laser light source and is held by the first driving section 321 and attached to the frame structure 302 .

The imaging unit 340 is a camera that captures the inspection light that has passed through the chip 501 , and is held by the second driving unit 322 and attached to the frame structure 302 . In this embodiment, the photographing unit 340 does not have a lens, and the inspection light (laser light) that has passed through the chip 501 is projected directly onto the imaging element and photographed.

The optical path regulating portions 350 are arranged at positions through which the optical axis O of the laser beam projected by the light projecting portion 330 passes. Each of the optical path regulating units 350 has a through hole 351. By arranging the light projecting unit 330 so that the laser beam passes through these two through holes, the optical path of the inspection light can be adjusted. .

FIG. 15 is a block diagram showing the control configuration of the inspection device 301. As shown in FIG.
The inspection apparatus 301 includes the holding unit 310, the light projecting unit 30, the imaging unit 40, the first driving unit 321, the second driving unit 322, and the like, as well as an imaging control unit 380 and an evaluation unit 380 for controlling operations. 390.

The imaging control unit 380 controls the imaging unit 40, the first driving unit 321, and the second driving unit 322 so that the imaging unit 340 performs imaging while the inspection light is appropriately projected onto the chip 501. , the inspection light is photographed. Here, the state in which the inspection light is appropriately projected onto the chip 501 refers to the state in which all the inspection light (laser light) is projected onto the diffractive optical element region 502 on the chip 501 .

FIG. 16 is a diagram showing a state in which inspection light is properly projected onto the chip 501. As shown in FIG.
FIG. 17 is a diagram showing an example of a projection image (image captured by the imaging unit) projected from the chip 501 in a state in which inspection light is appropriately projected onto the chip 501. FIG.
As shown in FIG. 16 , when the inspection light is properly projected onto the chip 501 , the projected light spot S from the light projecting section 330 is in the center of the chip 501 and out of the diffractive optical element region 502 . not In this case, for example, as shown in FIG. 17, there is no projection of unnecessary light other than the projection image made up of nine spots P. As shown in FIG.

FIG. 18 is a diagram showing a state in which the inspection light is projected onto the chip 501 at a position shifted from the proper position.
FIG. 19 is a diagram showing an example of a projection image (image captured by the imaging unit) projected from the chip 501 in a state in which the inspection light is projected onto the chip 501 at a position shifted from an appropriate position.
In the example shown in FIG. 18, the inspection light is not properly projected onto the chip 501, and the projected light spot S from the light projecting section 330 is located on the right side of the center of the chip 501, causing diffraction. It includes a portion that deviates to the right from the optical element region 502 . In this case, for example, as shown in FIG. 19, in addition to the projection image made up of nine spots P, unnecessary light R, which is originally unintended unnecessary light, is projected near the right side of the central spot P. will occur.
Here, the position where the unnecessary light R is generated corresponds to the direction in which the projected light spot S is shifted. That is, when the projected light spot S shifts to the left from the diffractive optical element region 502, the unnecessary light R shifts to the left of the spot P. FIG. Also, the larger the displacement of the projected light spot S, the larger the unwanted light R tends to be generated.
FIG. 20 is an enlarged view of the central spot P portion showing how the unnecessary light R is generated. In FIG. 20, the diagram at the center indicates a state in which the projected light spot S is not displaced, and the more leftward and rightward directions, the more the projected light spot S is displaced in that direction.

Utilizing such characteristics when the unnecessary light R is generated, the photographing control unit 380 of the present embodiment controls the driving of the first driving unit 321 and the second driving unit 322 as necessary to perform light projection. The spot S is projected onto a proper position on the diffractive optical element area 502 . That is, the image taken during the inspection is constantly monitored, and when the generation of the unnecessary light R is detected, the shift amount of the projected light spot S is estimated from the position and size of the generated unnecessary light R. Then, the driving amount of the first driving section 321 and the second driving section 322 is determined, and the driving of the first driving section 321 and the second driving section 322 is controlled based on the determined driving amount, so that the projected light spot S is The light projecting unit 330 and the photographing unit 340 are moved (adjustment drive) so that the light is projected at an appropriate position. Note that the units to be moved may be both the light projecting section 330 and the photographing section 340, or may be one of them.
After the adjustment drive is automatically performed, the inspection is performed again, and if the unnecessary light does not exist, the result of the reinspection is adopted. repeat the action. Further, in the above description, the shift in the left-right direction was exemplified, but the shift in any direction, such as the vertical direction or the oblique direction, can be appropriately adjusted.

In addition, in the inspection of one chip 501, the imaging control unit 380 of the present embodiment can be configured in a plurality of states in which the relative positional relationship between the chip 501 and the light projecting unit 330 differs in the rotation direction around the optical axis of the inspection light. take a picture. In this embodiment, imaging is performed in a direction in which the orientation of the chip 501 differs by 90° around the optical axis O of the inspection light. The operation of changing the orientation of the chip 501 can be easily performed by rotating the mounting direction of the movable block 312 with respect to the counterbore 311a by 90 degrees, as described above.
Here, the reason why the orientation of the chip 501 is changed by 90° and the photographing is performed is to prevent variation in the inspection result due to the influence of the polarization direction of the inspection light. In the diffractive optical element, the emitted light emitted from the diffractive optical element also changes depending on the polarization state of the projected light, so the influence thereof can be eliminated.

21A and 21B are diagrams for explaining multiple times of photographing and handling of the data.
In FIG. 21, the chip 501 is also marked with a triangular mark to indicate the direction of the chip 501 . The photographed image (projected image) photographed in the upper left state in FIG. 21 is assumed to be the upper right one in FIG. Here, the projected spots were numbered from 1 to 11.
Next, a photographed image (projected image) photographed in the state shown in the lower left of FIG. 21 is shown in the lower right of FIG. Thus, the position of the projection spot also rotates corresponding to the rotation of the chip 501 .
The evaluation unit 390, which will be described later, evaluates the amount of projected light based on the average value of the projected spot before rotation and the projected spot after rotation. . That is, the first projected spot before rotation is averaged with the first projected spot after rotation, and the second projected spot before rotation is averaged with the second projected spot after rotation. As a result, stable inspection can be performed without being affected by the polarization state of the laser light from the light projecting section 330 .
In the above example, the rotation is performed by 90°, but the measurement may be performed many times at a finer angular pitch. Further, in this embodiment, the rotation of the chip 501 itself is manually operated by the operator, but this may also be configured to be performed automatically.

Returning to FIG. 15 , the evaluation unit 390 evaluates the light distribution characteristics of the chip 501 based on the image information obtained by the imaging unit 340 . In this embodiment, as described above, the chip 501 is rotated by 90° and the average value is obtained for each projection spot before and after rotation to evaluate the light amount. As for the orientation characteristics, it is preferable to use an optimal algorithm as an evaluation method depending on what kind of light distribution characteristics the chips 501 of the diffractive optical element sheet 500 to be inspected are seeking.

As described above, according to the third embodiment, the imaging control unit 380 detects the presence of unnecessary light, and when the unnecessary light is detected, the first driving unit 321 and the second driving unit 322 are activated. It is driven and controlled so that the inspection light is projected at an appropriate position. Therefore, correct inspection can always be performed.
In addition, the photographing control unit 380 changes the direction of the chip 501 and photographs a plurality of times. Correct inspection can be performed without being affected by Therefore, even if the light source of the light projecting section 330 is replaced, it is possible to perform correct inspection.

(deformed form)
Various modifications and changes are possible without being limited to the embodiments described above, and they are also within the scope of the present invention.

(1) In each embodiment, the distance measuring unit 37 has been described by citing an example provided in the light projecting unit 30 . For example, the distance measuring section may be provided in the photographing section or may be provided in the holding section, and the position thereof may be changed as appropriate.

(2) In each embodiment, an example has been described in which the adjustment control unit 70 automatically adjusts the orientation (inclination) of each part. Alternatively, for example, the inclination of each part may be manually adjusted based on the measurement result of the distance measuring part 37 .

(3) In each embodiment, the diffractive optical element sheet 500 has been described, but the object to be inspected is not limited to the sheet, and may be a film or a plate.

(4) In each embodiment, an example has been described in which a distance measurement unit is provided and the orientation (inclination) of each part is adjusted based on the measurement result. Not limited to this, for example, a mark M (see FIGS. 22 and 23) is provided on a part of the holding part 10 or a part of the diffractive optical element sheet 500, and the direction (tilt) of each part is used by using this. ) may be adjusted.
FIG. 22 is a diagram showing an example in which a mark M is provided on part of the holding portion 10. As shown in FIG.
FIG. 23 is a diagram showing an example in which a mark M is provided on a portion of the diffractive optical element sheet 500. As shown in FIG.
The mark M shown in FIGS. 22 and 23 is a diffraction grating that diffracts light of the same wavelength as the inspection light projected by the light projecting section 30 . Therefore, by projecting inspection light onto the mark M, a pattern is projected from the diffraction grating of the mark M at a predetermined position. The direction and inclination of each part may be adjusted using this projected pattern.

(5) In the third embodiment, an example has been described in which the chips 501 are held one by one by the movable block portion 312 and inspected. Alternatively, for example, a plurality of chips 501 may be held by the movable block.
FIG. 24 is a diagram showing an example of a movable block capable of holding multiple chips.
The example of FIG. 24 shows a movable block 412 capable of holding nine chips 501 . The movable block 412 is provided with six chip mounting counterbore portions 312a and six through holes 312b. When arranging a plurality of chips 501 in this way, for example, if an XY stage that can be driven and controlled is provided also in the holding unit, inspection can be performed efficiently.

(6) In the third embodiment, by rotating the movable block 312, the relative direction between the polarization direction of the inspection light and the chip 501 is changed. For example, the configuration may be such that the light projecting section side is rotated.

In addition, although each embodiment and modification can also be combined and used suitably, detailed description is abbreviate|omitted. Moreover, the present invention is not limited to each embodiment described above.

1 inspection device 10 holding part 11 holding part adjustment part 12 compression spring 13 opening 20 drive part 30 light projection part 31 light projection part adjustment part 32 base 33 laser light source 34 collimator lens 35 variable aperture 36 light source rotation part 37 distance measurement part 38 frame 39 filter holding unit 40 imaging unit 41 imaging unit adjustment unit 42 pedestal 43 collimator lens 50 screen 51 screen adjustment unit 52 pedestal 60 base 61 straight rail 70 adjustment control unit 80 imaging control unit 90 evaluation unit 201 inspection device 301 inspection device 302 Frame structure 310 Holding portion 311 Body portion 311a Counterbore portion 311b Through hole 312 Movable block portion 312a Chip mounting counterbore portion 312b Through hole 312c Knob portion 321 First drive portion 322 Second drive portion 330 Light Projector 340 Photographer 350 Optical path definition Part 351 Through hole 380 Imaging control part 390 Evaluation part 412 Movable block 500 Diffractive optical element sheet 501 Chip 502 Diffractive optical element region M Mark

Claims (22)

An inspection apparatus for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface,
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
a distance measuring unit capable of measuring at least one of the distances between the light projecting unit, the holding unit, and the photographing unit at a plurality of locations;
an adjusting unit capable of adjusting at least an intersection angle between the optical axis of the inspection light and the imaging surface of the imaging unit, and an intersection angle between the optical axis of the inspection light and the sheet surface of the diffractive optical element sheet;
inspection device. An inspection apparatus for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface,
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
a mark provided on the holding portion or provided on a portion of the diffractive optical element sheet held by the holding portion;
with
The photographing unit is capable of photographing the mark directly or the inspection light transmitted through the mark,
An adjusting unit capable of adjusting at least an intersection angle between the optical axis of the inspection light and the imaging surface of the imaging unit and an intersection angle between the optical axis of the inspection light and the surface of the diffractive optical element sheet. Inspection equipment provided. An inspection apparatus for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface,
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
with
The light projecting unit
a laser light source;
a collimator lens;
variable aperture;
with
An inspection apparatus further comprising a light source rotating section that can rotate at least the laser light source about an optical axis of the laser light. An inspection apparatus for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface,
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
a relative position changing section capable of changing the relative positional relationship between the unit diffractive optical element and the light projecting section in a rotational direction about the optical axis of the inspection light;
with
The imaging control section performs imaging in a plurality of states with different relative positional relationships between the unit diffractive optical element and the light projecting section. In the inspection apparatus according to any one of claims 1 to 4 ,
an optical system disposed between the imaging unit and the diffractive optical element sheet for deflecting an optical path of the inspection light transmitted through the diffractive optical element sheet;
An inspection device characterized by: In the inspection apparatus according to any one of claims 1 to 4 ,
further comprising a screen onto which the inspection light transmitted through the diffractive optical element sheet is projected;
the imaging unit imaging the inspection light projected onto the screen;
An inspection device characterized by: In the inspection apparatus according to any one of claims 1 to 6 ,
the holding section holds the diffractive optical element sheet such that the sheet surface of the diffractive optical element sheet is oriented along the vertical direction;
An inspection device characterized by: In the inspection apparatus according to any one of claims 1 to 7,
The imaging control unit repeatedly moves and stops the holding unit, and performs imaging by the imaging unit while the holding unit is stopped;
An inspection device characterized by: In the inspection apparatus according to any one of claims 1 to 8,
With respect to photographing the unit diffractive optical elements arranged in at least one direction, the photographing control unit performs photographing by the photographing unit while continuing the movement of the holding unit;
An inspection device characterized by: In the inspection device according to claim 8 or claim 9,
The imaging control unit uses preset imposition information and alignment information to calculate the position of the unit diffractive optical element and determine the timing of imaging;
An inspection device characterized by: In the inspection device according to claim 10 when citing claim 9,
While the inspection light is projected onto the diffractive optical element region in which the pattern of the unit diffractive optical element is formed, the imaging control unit continues imaging or performs imaging a plurality of times;
An inspection device characterized by: In the inspection device according to any one of claims 1 to 11,
comprising an evaluation unit that evaluates the light distribution characteristics of the unit diffractive optical element based on information obtained by photographing by the photographing unit;
An inspection device characterized by: In the inspection device according to claim 12,
The unit diffractive optical element splits incident light into a plurality of beams and distributes the light beams to a plurality of different positions,
The evaluation unit quantifies at least one of brightness, size, and position at each position of the projected image of the split light;
An inspection device characterized by: In the inspection device according to claim 13,
The evaluation unit quantifies the uniformity of all projection images of the split light;
An inspection device characterized by: An inspection apparatus for inspecting individualized unit diffractive optical elements,
a holding section that holds the unit diffractive optical element;
a light projecting unit that projects inspection light onto the unit diffractive optical element held by the holding unit;
an imaging unit that captures the inspection light that has passed through the unit diffractive optical element;
a driving unit that moves at least one of the holding unit, the light projecting unit, and the photographing unit;
an imaging control unit that controls the imaging unit and the driving unit so that the imaging unit performs imaging while the inspection light is projected onto at least the unit diffractive optical element, and performs imaging of the inspection light; and,
a relative position changing section capable of changing the relative positional relationship between the unit diffractive optical element and the light projecting section in a rotational direction about the optical axis of the inspection light;
with
The imaging control section performs imaging in a plurality of states with different relative positional relationships between the unit diffractive optical element and the light projecting section. In the inspection device according to claim 15,
The holding section holds at least a portion of an outer diameter shape of the unit diffractive optical element viewed in a direction along the optical axis of the inspection light, thereby allowing the unit diffractive optical element to rotate around the optical axis of the inspection light. An inspection device that regulates the rotation of elements. In the inspection device according to any one of claims 1 to 16,
When noise light other than the predetermined light distribution is detected in the photographing result, the photographing control unit controls the driving unit to change the position at which the inspection light is irradiated to the unit diffraction optical element, and to take pictures,
An inspection device characterized by: An inspection method for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface, comprising:
The inspection device
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
a distance measuring unit;
an adjustment unit;
with
the distance measuring unit measures at least one of the distances between the light projecting unit, the holding unit, and the photographing unit at a plurality of locations;
The adjustment unit adjusts at least an intersection angle between the optical axis of the inspection light and the imaging surface of the imaging unit, and an intersection angle between the optical axis of the inspection light and the sheet surface of the diffractive optical element sheet. matter,
An inspection method characterized by An inspection method for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface, comprising:
The inspection device
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
a mark provided on the holding portion or provided on a portion of the diffractive optical element sheet held by the holding portion;
an adjustment unit;
with
The photographing unit photographs the mark directly or the inspection light transmitted through the mark,
The adjustment unit adjusts at least an intersection angle between the optical axis of the inspection light and the imaging surface of the imaging unit, and an intersection angle between the optical axis of the inspection light and the sheet surface of the diffractive optical element sheet. matter,
An inspection method characterized by An inspection method for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface, comprising:
The inspection device
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
a light source rotating part;
with
The light projecting unit
a laser light source;
a collimator lens,
variable aperture;
with
The light source rotating unit rotates at least the laser light source about the optical axis of the laser light;
An inspection method characterized by An inspection method for inspecting a diffractive optical element sheet in which a plurality of unit diffractive optical elements are arranged in the sheet surface, comprising:
The inspection device
a holding portion that holds the diffractive optical element sheet and is movably provided;
a driving unit that moves the holding unit in a direction along the sheet surface of the diffractive optical element sheet;
a light projecting unit that projects inspection light onto the diffractive optical element sheet held by the holding unit;
an imaging unit that captures the inspection light that has passed through the diffractive optical element sheet;
photographing control for sequentially photographing the inspection light by controlling the photographing unit and the driving unit so that the photographing unit photographs with the inspection light being projected onto at least the unit diffractive optical element; Department and
a relative position changer;
with
The relative position changing section changes the relative positional relationship between the unit diffractive optical element and the light projecting section in a rotational direction about the optical axis of the inspection light,
The imaging control section performs imaging in a plurality of states in which the relative positional relationship between the unit diffractive optical element and the light projecting section is different;
An inspection method characterized by An inspection method for inspecting a singulated unit diffractive optical element, comprising:
The inspection device
a holding section that holds the unit diffractive optical element;
a light projecting unit that projects inspection light onto the unit diffractive optical element held by the holding unit;
an imaging unit that captures the inspection light that has passed through the unit diffractive optical element;
a driving unit that moves at least one of the holding unit, the light projecting unit, and the photographing unit;
an imaging control unit that controls the imaging unit and the driving unit so that the imaging unit performs imaging while the inspection light is projected onto at least the unit diffractive optical element, and performs imaging of the inspection light; and,
a relative position changer;
with
The relative position changing section changes the relative positional relationship between the unit diffractive optical element and the light projecting section in a rotational direction about the optical axis of the inspection light,
The imaging control section performs imaging in a plurality of states in which the relative positional relationship between the unit diffractive optical element and the light projecting section is different;
An inspection method characterized by

Images