JP2020034650A - Diffraction optical element, multiple-surfaced body of diffraction optical element, method for managing diffraction optical element, and method for inspecting diffraction optical element - Google Patents

Abstract

To provide a diffraction optical element which can secure the traceability of each manufactured product, a multiple-surfaced body of a diffraction optical element, a method for managing a diffraction optical element, and a method for inspecting a diffraction optical element.SOLUTION: A diffraction optical element 1 includes a base material 1a and a resin layer 1b in the base material 1a, the resin layer 1b having a shaped pattern which fits to a molded pattern, and the shaped pattern having a diffraction grating 10, a pattern identification code 20 for identifying a molded pattern, and a position identification code 30 for identifying the position of the diffraction optical element 1 in the molded pattern.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a diffractive optical element, a multi-faced body of the diffractive optical element, a method for managing the diffractive optical element, and a method for inspecting the diffractive optical element.

  In recent years, applications of sensor systems have been expanding. There are various types of sensors, and information to be detected is also various. As one of the means, there is a method in which light is emitted from a light source to an object, and information is obtained from reflected light. For example, a pattern authentication sensor, an infrared radar, and the like are examples.

  The light source of these sensors has a wavelength distribution, brightness, spread, and the like according to the application. The wavelength of light is often in the range from visible light to infrared light. In particular, infrared rays are widely used because they are hardly affected by external light, are invisible, and can observe a little inside of an object. As the type of the light source, an LED light source, a laser light source, and the like are often used. For example, when detecting a distant place, a laser light source with a small spread of light is preferably used, and when detecting a relatively close place, when irradiating an area having a certain spread, an LED light source is preferable. Used for

By the way, the size, shape, and the like of the target irradiation area do not always match the spread (profile) of the light from the light source, and it is necessary to shape the light with a diffusion plate, a lens, a shielding plate, and the like. is there. Means for shaping light include a diffractive optical element (DOE). This is an application of the diffraction phenomenon when light passes through places where materials having different refractive indices are arranged with periodicity. The diffractive optical element is basically designed for light of a single wavelength, but can theoretically shape the light into almost any shape. Further, in the diffractive optical element, it is possible to control the uniformity of the light distribution in the irradiation area. Such characteristics of the diffractive optical element are advantageous in terms of increasing the efficiency by suppressing the irradiation of unnecessary regions and reducing the size of the apparatus by reducing the number of light sources.
In addition, the diffractive optical element can be used for both a parallel light source such as a laser and a diffuse light source such as an LED, and can be applied to a wide range of wavelengths from ultraviolet light to visible light and infrared light. is there.

  When such a diffractive optical element is applied to a highly accurate sensor, extremely high accuracy is required. In order to achieve high accuracy, traceability that enables tracking of the manufacturing history of a diffractive optical element in which a defect has occurred is important. However, conventionally, traceability has hardly been considered in diffractive optical elements. In the case of manufacturing a diffractive optical element, a multi-faced body in which thousands of diffractive optical elements are multi-faced on a single sheet may be used in a manufacturing process (for example, Patent Document 1). In such a case, since the diffractive optical element is manufactured in a large amount by one molding, it is more difficult to secure traceability.

JP 2018-122384 A

  An object of the present invention is to provide a diffractive optical element, a multi-faced body of a diffractive optical element, a method of managing the diffractive optical element, and a method of inspecting the diffractive optical element, which can ensure traceability of each manufactured product.

  The present invention solves the above problem by the following means. In addition, in order to make it easy to understand, description is given with reference numerals corresponding to the embodiment of the present invention, but the present invention is not limited to this.

  A first invention is a diffractive optical element (1) including a substrate (1a) and a resin layer (1b) formed on the substrate (1a), wherein the resin layer (1b) is And a shaping shape corresponding to the shape formed on the molding die, wherein the shaping shape includes a diffraction grating (10), a type identification code (20) for identifying the molding die, and the molding die. And a position identification code (30) for identifying the position of the diffractive optical element (1).

  According to a second aspect of the present invention, in the diffractive optical element (1) according to the first aspect, the formed shape includes a defect sample (40, 40a, 40b, 40c) formed to a predetermined dimension. This is a diffractive optical element (1).

  According to a third invention, in the diffractive optical element (1) according to the second invention, the defect samples (40, 40a, 40b, 40c) include a plurality of defect samples (40a, 40b, 40c) having different dimensions. The diffractive optical element (1), which is arranged side by side.

  A fourth invention is a multi-faced body (500) of the diffractive optical element (1), wherein the diffractive optical element (1) according to any one of the first invention to the third invention is multi-faced. .

  A fifth invention is a method for managing a diffractive optical element (1) according to any one of the first to third inventions, wherein the multi-faced body (500) of the diffractive optical element (1) is formed. A unique lot ID is set for each, the multi-faced body (500) is cut into individual diffractive optical elements (1), and the cut diffractive optical elements (1) are stored in a plurality of housing members ( 600) is a method for managing the diffractive optical element (1), wherein the lot ID set for each molding is assigned to all of the accommodating members (600).

  A sixth invention is the method for inspecting a diffractive optical element (1) according to any one of the first invention to the third invention, wherein the diffractive optical element (1) is multi-faced. It is molded in the form of a body (500), and at least the optical performance is inspected in the state of the multi-faced body (500), and the multi-faced body (500) is cut into individual diffractive optical elements (1), and cut. The plurality of diffractive optical elements (1) are housed separately in a plurality of housing members (600), and at least inspection of foreign matter adhesion is performed in a state of being housed in the housing members (600). This is the inspection method 1).

  ADVANTAGE OF THE INVENTION According to this invention, the diffractive optical element which can ensure the traceability of each manufactured product, the multi-faced body of a diffractive optical element, the management method of a diffractive optical element, and the inspection method of a diffractive optical element can be provided.

FIG. 2 is a diagram showing an embodiment of the diffractive optical element 1 according to the present invention. It is sectional drawing cut | disconnected in the position of arrow GG in FIG. FIG. 9 is a plan view showing an example of a diffractive optical element in which the unevenness of the diffraction grating viewed from the normal direction of the sheet surface is formed in a regular or irregular pattern in which the boundary between the convex portion and the concave portion includes a curved line. A plan view showing an example of a diffractive optical element in which the concave-convex shape of the diffraction grating viewed from the normal direction of the sheet surface is formed in a lattice-like pattern in which a plurality of unit cells in which the same concave-convex shape are arranged side by side are tiled. It is. FIG. 4 is a perspective view showing an example of a partial periodic structure in the example of the irregular diffractive optical element shown in FIG. 3. FIG. 5 is a perspective view illustrating an example of a partial periodic structure in the example of the GCA type diffractive optical element illustrated in FIG. 4. It is sectional drawing which cut | disconnected the diffractive optical element in the position of arrow G-G 'in FIG. FIG. 3 is a diagram illustrating a diffractive optical element. FIG. 4 is a diagram showing a multi-faced body 500 on which the diffractive optical element 1 is multi-faced. It is the figure which expanded a part of multiple imposition body 500. It is the figure which expanded and showed the area | region in which the type identification code 20 and the defect sample 40 were formed. FIG. 9 is a diagram illustrating a state where the diffractive optical element 1 is housed in a housing member 600. It is a figure explaining a foreign substance inspection.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(1st Embodiment)
FIG. 1 is a diagram showing an embodiment of a diffractive optical element 1 according to the present invention.
FIG. 2 is a cross-sectional view taken along a line GG in FIG.
Each of the drawings shown below, including FIGS. 1 and 2, is a schematic diagram, and the size and shape of each part are exaggerated as appropriate for easy understanding.
In the following description, specific numerical values, shapes, materials, and the like will be described, but these can be changed as appropriate.
Also, in the present invention, shapes and geometric conditions, and terms that specify their degree, for example, such as "parallel", "orthogonal", "same" and the like, and the value of the length and angle, etc. The interpretation is not limited to the strict meaning, but includes a range in which a similar function can be expected.
Further, in the present invention, the term “transparent” means a material that transmits at least light having a wavelength to be used. For example, even if it does not transmit visible light, if it transmits infrared light, it is treated as transparent when used for infrared light.

The diffractive optical element 1 according to the present embodiment includes a base 1a and a resin layer 1b.
The substrate 1a is a layer serving as a base of the diffractive optical element 1, and various transparent resin films, resin sheets, and the like can be used.
As the substrate 1a, for example, polycarbonate (PC) resin, polyethylene terephthalate (PET) resin, methyl methacrylate / butadiene / styrene (MBS) resin, methyl methacrylate / styrene (MS) resin, acrylic / styrene (AS) resin And a transparent resin such as acrylonitrile-butadiene-styrene (ABS) resin. Further, the substrate 1a may be configured using a glass substrate. Although not shown, an adhesive layer may be provided on the base material 1a to enhance the adhesiveness with the applied ultraviolet curable resin or the like.

  The resin layer 1b is formed on the substrate 1a, and has a shaping shape (10, 20, 30, 40, 50, etc.) corresponding to the shape formed in the molding die. The resin layer 1b is formed, for example, by molding a UV-curable resin applied on the base material 1a and transferring the concave-convex pattern using a molding die on which a concave-convex pattern corresponding to each pattern of the above-described shape is formed. It can be formed by irradiating ultraviolet rays to cure.

  As the ultraviolet curable resin, for example, urethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, polythiol, butadiene acrylate and the like can be used. Note that the material for forming the resin layer 1b is not limited to an ultraviolet curable resin. The resin layer 1b may be formed of, for example, an electron beam curing resin. In addition, the resin layer 1b may be configured using a thermosetting or ultraviolet curable SOG (Spin on Glass). Further, each pattern is not limited to the example of transferring from the original by molding, but may be molded using an intermediate plate of a resin produced from an original having the concavo-convex shape of each pattern.

  The resin layer 1 b includes a diffraction grating 10, a type identification code 20, a position identification code 30, a defect sample 40, and a cutting position mark 50 as a shaped shape.

The diffraction grating 10 is arranged at the center of the diffractive optical element 1, and is constituted by a large number of fine irregularities.
FIG. 3 is a plan view showing an example of a diffractive optical element in which the unevenness of the diffraction grating viewed from the normal direction of the sheet surface is formed in a regular or irregular pattern in which the boundary between the convex portion and the concave portion includes a curved line. FIG.
In the present embodiment, as an example, the present invention can be applied to a diffractive optical element having an irregularly-shaped pattern that looks irregular at first glance as shown in FIG. In the following description, the diffractive optical element of the type shown in FIG. 3 will be referred to as an irregular type. However, this irregular pattern may be a regular pattern depending on the intended emission pattern of the diffractive optical element. Therefore, the term “irregular type” is a name for convenience and is limited to irregular. It does not do. Further, in FIG. 3, the irregular pattern is constituted by a curve, but depending on the intended emission pattern of the diffractive optical element, a pattern that is a straight line or a polygonal line connecting the segments formed by the curve. May be included. Therefore, in the pattern of the irregular diffraction grating, the boundary between the convex portion and the concave portion connects a curve and a plurality of line segments when viewed from the normal direction of the surface on which the uneven shape of the high refractive index portion (described later) is formed. It includes at least one of a broken line. Further, a plurality of unit cells may be arranged in a lattice pattern with a specific irregular pattern as a unit cell.

FIG. 4 shows an example of a diffractive optical element in which the concave-convex shape of the diffraction grating viewed from the normal direction of the sheet surface is formed in a lattice-like pattern in which a plurality of unit cells in which the same concave-convex shape are arranged side by side are tiled. FIG.
In the present embodiment, as another example, as shown in FIG. 4, the present invention can be applied to a diffractive optical element in which a plurality of unit cells in which the same concavo-convex shape is arranged are formed in a grid-like pattern in which a plurality of tiles are tiled. it can. In the following description, this type of diffractive optical element shown in FIG. 4 is also referred to as a grating cell array (Grating Cell Array) type or a GCA type. In a grating cell array type diffractive optical element, the direction and angle of light diffracted by a diffraction grating are different for each unit cell, and a diffractive optical element capable of obtaining desired optical characteristics by tiling a number of unit cells. An element is configured. That is, in the grating cell array type diffractive optical element, the high refractive index portion is partitioned in a lattice shape when viewed from the normal direction of the surface on which the uneven shape is formed, and extends in a specific direction within the partition. The convex portions having the same shape are arranged side by side in a direction orthogonal to the specific extending direction, and the width and the extending direction of the convex portions are different for each section.

FIG. 5 is a perspective view showing an example of a partial periodic structure in the example of the irregular diffractive optical element shown in FIG.
FIG. 6 is a perspective view showing an example of a partial periodic structure in the example of the GCA type diffractive optical element shown in FIG.
FIG. 7 is a cross-sectional view of the diffractive optical element taken along a line GG ′ in FIG.
FIG. 8 is a diagram illustrating a diffractive optical element.

In the present invention, “shaping light” refers to controlling the traveling direction of light so that the shape (irradiation region) of light projected on a target object or a target region becomes an arbitrary shape. . For example, as shown in the example of FIG. 8, a light source unit 210 that emits light 201 (FIG. 8B) whose irradiation area 202 becomes circular when directly projected onto a flat screen 200 is prepared. By transmitting the light 201 through the diffractive optical element 1 of the present invention, the irradiation area 204 can be formed into a target shape such as a square (FIG. 8A), a rectangle, a circle (not shown), or the like. "Shaping light".
In addition, by combining the light source unit 210 and at least one diffractive optical element 1 of the present embodiment, which is disposed at a position where light emitted by the light source unit 210 passes, light that can be irradiated in a shaped state It can be an irradiation device.

The diffractive optical element 1 of the present embodiment is a diffractive optical element (DOE) for shaping light. The diffraction grating 10 of the diffractive optical element 1 has a cross shape, specifically, for example, ± 50 degrees and a width of ± 3.3 with respect to the light from the light source unit 210 that emits light with a wavelength of 500 nm. It is designed to spread light in a shape with two light bands that spread at different degrees.
The depth of the diffraction grating 10 of the present embodiment differs at each of the positions A, B, C, and D shown in FIG. That is, the diffraction grating 10 has a multi-step shape having four different heights. The diffraction grating 10 usually has a plurality of regions having different periodic structures (partial periodic structures: for example, the E and F regions in FIG. 3). 5 and 6, an example of the partial periodic structure is extracted and shown.

  As shown in FIG. 7, the diffraction grating 10 includes a high refractive index portion 11 in which a plurality of convex portions 11a are arranged in a sectional shape. In the GCA type diffractive optical element, the high refractive index portion 11 extends in the depth direction of the cross section while maintaining the same cross-sectional shape. On the other hand, in the case of an irregular diffractive optical element, if the cross-sectional position changes, the cross-sectional shape changes, so that a large number of diffraction gratings having various cross-sectional shapes are arranged.

  The upper portion of FIG. 3 including the concave portion 12 formed between the convex portions 11a and the space 13 near the top of the convex portion 11a contains air, and has a higher refractive index than the high refractive index portion 11. Is a low refractive index portion 14 having a low refractive index. The diffraction layer 15 having the function of shaping light is configured by a periodic structure in which the high refractive index portions 11 and the low refractive index portions 14 are alternately arranged.

The convex portion 11a has a multi-stage shape including four step portions having different heights on one side (left side in FIG. 7) of the side surface shape. Specifically, the protruding portion 11a has the most protruding level 3 step portion 11a-3, the level 2 step portion 11a-2 lower than the level 3 step portion 11a-3, and the level 2 step portion 11a-2. Has a level 1 step portion 11a-1 which is lower by one step and a level 0 step portion 11a-0 which is lower by 1 step than the level 1 step portion 11a-1 on one side. The other side (the right side in FIG. 7) of the side surface shape of the convex portion 11a is a side wall portion 11b that extends linearly from the level 3 step portion 11a-3 to the level 0 step portion 11a-0.
The protruding portion 11a of the present embodiment is a shape in which a sawtooth shape is simulated by a multi-step contour shape. Since the four-level shape has been described, the convex portion 11a has a relatively coarse shape. If the number of levels is further increased, the shape can be more accurately imitated.

FIG. 9 is a diagram showing a multi-faced body 500 on which the diffractive optical element 1 is multi-faced.
FIG. 10 is an enlarged view of a part of the multi-faced body 500.
Since the diffractive optical element 1 of the present embodiment is a very small member having an outer shape of, for example, about 3 mm × 3 mm, during the manufacturing process, a large number of diffractive optical elements 1 are formed as shown in FIG. It is manufactured as a multi-faced body 500 arranged side by side to improve the efficiency of the manufacturing process. The diffractive optical element 1 is manufactured by cutting the multi-faced body 500 into individual pieces. In FIG. 9, for easy understanding, a boundary line is drawn by a solid line at a boundary between adjacent diffractive optical elements 1. However, since this boundary line is not formed before cutting, FIG. , Is indicated by a two-dot chain line. Note that FIG. 9 shows a state in which a total of 100 diffractive optical elements 1 of 10 rows × 10 columns are arranged in order to enable illustration and facilitate understanding. However, actually, more diffractive optical elements 1 are arranged. For example, there are cases where thousands to tens of thousands of diffractive optical elements 1 are arranged on one multi-faced body 500.
The following description will be made on the assumption that the diffractive optical element 1 is manufactured by cutting the multi-faced body 500 in this manner.

  Returning to FIGS. 1 and 2, the mold identification code 20 is a code for identifying a molding die, and is described as “900A” in the example shown in FIG. 1. The mold identification code 20 is a code peculiar to the molding die, and it is possible to determine which molding mold the diffractive optical element 1 is formed by using the mold identification code 20. Since the type identification code 20 is a code unique to the molding die, it is the same for all the diffractive optical elements 1 in the multi-faced body 500 (see FIG. 10).

FIG. 11 is an enlarged view of a region where the type identification code 20 and the defect sample 40 are formed.
As shown in FIG. 11, the type identification code 20 is divided into a large number of lines and is configured as an uneven shape. For example, a black portion in FIG. Or, it is formed as a concave portion which is more concave than other portions). The reason why the configuration such that characters and the like are represented by the concavo-convex shape is to improve visibility. It should be noted that the present invention is not limited to the line and space pattern as shown in FIG. 11, but may be an aggregate of at least one pattern such as a line and space pattern, a hole pattern, and a dot pattern. In the diffractive optical element 1 of the present embodiment, not only the type identification code 20 and the defect sample 40 shown in FIG. 11 but also a position identification code 30 and a cutting position mark 50 described later are similarly configured.

The position identification code 30 is a code for identifying the position of the diffractive optical element 1 in the mold. In the example of FIG. 9, since one molding die has 100 portions where the diffractive optical element 1 is molded, it is possible to specify at which of the 100 locations the diffractive optical element 1 is molded. The position identification code 30 is provided as a simple code. The example of FIG. 1 shows an example of “X49, Y53”, which is the 49th column in the X direction (the horizontal direction in FIGS. 9 and 10) and the Y direction (FIG. 9, FIG. 10 indicates the position of the 53rd row (vertical direction). Note that the display is not limited to the display such as the column number and the row number as in this example, and may be a numerical value or the like starting from 1. Further, the configuration may be such that the type identification code 20 and the position identification code 30 are combined and one code has both functions. In the above case, for example, “900A-X49Y53” may be used.
Since the mold identification code 20 and the position identification code 30 are provided, it is possible to easily specify which mold is manufactured and at which position even if the diffractive optical element 1 is singulated. It is.

  The defect sample 40 is a mark formed in a predetermined size, and is provided for an inspector to refer to at the time of a visual inspection. For example, even if an inspection standard is set such that a defect larger than 40 μm is determined as a defective product, it is difficult to determine the size of the defect only by training of an inspector. It is also difficult to unify the criteria for each inspector. Therefore, by making it possible to observe a portion where there is a possibility of a defect by comparing it with the defect sample 40, it is possible to improve the accuracy of the inspection and to facilitate the training of inspectors.

  When one defect sample 40 is provided, it is desirable that its size be a size that is a threshold value for judging a defect or a size that is slightly smaller than the threshold value. For example, when a defect larger than 40 μm is regarded as a defective product as described above, the defect sample 40 may be a square of 40 μm × 40 μm, a circle of 40 μm in diameter, or a square of 30 μm × 30 μm. Or a circle having a diameter of 30 μm. The shape is not limited to a square or a circle, but may be a rectangle or an ellipse. Furthermore, if the tendency of the generated defect is known, the defect sample 40 may be configured to have a shape close to the defect to facilitate comparison at the time of inspection. For example, when the adhesion of hair frequently occurs as a defect, for example, the defect sample 40 may be configured as a rectangle of 2 μm × 2000 μm.

  Further, in the present embodiment, three defect samples 40a, 40b, and 40c having different dimensions are arranged in order of size. In the present embodiment, as described above, it is assumed that a defect larger than 40 μm is regarded as a defective product, and accordingly, the defect sample 40a is a 40 μm × 40 μm square, and the defect sample 40b is A 30 μm × 30 μm square is used, and the defect sample 40 a is a 20 μm × 20 μm square. In this way, by arranging the defect samples 40 whose dimensions gradually change at a constant rate, the inspector can grasp the size of the target object (a part that may have a defect) when observing it. The effect of making it easier can be expected. A number or the like indicating the size of each of the defect samples 40a, 40b, and 40c may be further arranged near each defect sample.

  The cutting position mark 50 is a mark used as a guide of a cutting position when the multi-faced body 500 is cut into individual diffractive optical elements 1. The cutting position mark 50 may remain on the diffractive optical element 1 after cutting as shown in FIG. 1, or may be configured to be removed at the time of cutting and not remain on the diffractive optical element 1.

Next, a method for managing the diffractive optical element 1 of the present embodiment will be described.
As described above, even if the diffractive optical element 1 of the present embodiment is provided with the mold identification code 20 and the position identification code 30 even in the form of individual pieces, Can be easily specified. However, it is not possible to specify the time of manufacture with these alone. Naturally, since the mold is used repeatedly, even if it is manufactured using the same mold, the condition of the molded product depends on various conditions such as differences in various conditions during molding and differences in the number of times the mold is used. Big changes also occur. Therefore, it is important to specify the manufacturing time from the viewpoint of traceability.
Therefore, in the method of managing the diffractive optical element 1 of the present embodiment, each time the multi-faced body 500 is molded, a unique lot ID is set for each molding (molding process, molding operation). This lot ID is assigned to a housing member that houses the individualized diffractive optical element 1 so that the molding time of the diffractive optical element 1 can be specified. In the present embodiment, the type identification code 20, the position identification code 30, and the lot ID are managed so that they can be recognized even after manufacturing, and the diffractive optical element 1 is used to determine which position of which mold, when, and when. It is possible to accurately grasp whether the operation has been performed, and it is possible to secure traceability.

FIG. 12 is a diagram illustrating a state where the diffractive optical element 1 is housed in the housing member 600.
The diffractive optical element 1 of the present embodiment is housed separately in the housing member 600 for each number smaller than the number of the diffractive optical elements 1 provided on the multi-faced body 500. In the example of FIG. 12, the housing member 600 includes nine housing portions 601, and the diffractive optical elements 1 are housed in the housing member 600 separately for every nine. Therefore, when the diffractive optical element 1 is cut from the multi-faced body 500 in which 100 diffractive optical elements 1 are arranged, nine diffractive optical elements 1 are accommodated in 11 accommodating members 600 separately. . In this housing, it is desirable that the diffractive optical elements 1 whose arrangement regions in the multi-faced body 500 are close are housed in the same housing member 600. On the multi-faced body 500, there may be a case where the molding portion is deviated or the like, and it is more convenient to collect the diffractive optical elements 1 that are arranged close together in the event of a defect or the like. is there. The fraction (in this case, one piece) is stored as a sample at the time of manufacture. It is desirable to keep the sample at the time of manufacture even when fractions do not occur.

  Here, the accommodation member 600 is provided with a lot ID display section 602 on which the above-mentioned lot ID is displayed. Since the lot ID displayed on the lot ID display section 602 is a unique ID for each molding, in the above-described example, the same lot ID (“Lot in FIG. -ID20180808-25 ”) is displayed. “Lot-ID20180808-25” illustrated in FIG. 12 indicates that it is the 25th molding on August 8, 2018. Note that this lot ID is merely an example, and may be a complete serial number, a numerical value representing the time at which molding was performed may be added, or information such as molding conditions and a manufacturing factory may be included. The specific form may be any form. Further, the lot ID display unit 602 may have a form in which a label is attached, may be formed by laser printing or the like, may be more simply handwritten, and may have any form. In addition, the same lot ID is given to the above-mentioned stored sample as the lot ID.

  Actually, for example, 200 pieces of the diffractive optical elements 1 cut from the multi-faced body 500 in which 5000 diffractive optical elements 1 are arranged are housed in the housing member 600, for example. From the viewpoint of manufacturing efficiency, it is desirable to manufacture a large number of diffractive optical elements 1 at once using the multi-faced body 500. On the other hand, if a large number of diffractive optical elements 1 are housed in one housing member 600 just because they are in the same lot, it is not easy to handle and it is impractical. After that, the diffractive optical element 1 is often used in combination with a light source or the like, and it is desirable that the diffractive optical element 1 be accommodated in a suitable number for the assembling process. In this embodiment, the diffractive optical element 1 is accommodated in the accommodating member 600 in a predetermined number, and a unique lot ID is assigned to each molding. Traceability can be secured without impairing the performance. In addition, since the same lot ID is assigned to all of the housing members 600 that house the diffractive optical element 1 formed at the same time, even if the housing members 600 are separately handled afterwards, traceability is maintained. Do not lose.

  Further, in a field other than the diffractive optical element, in a case where a lot ID is given in a manufacturing process at the time of mass production, an individual lot ID is conventionally given to each accommodating member. However, if an individual lot ID is assigned to each storage member, in order to ensure traceability at the time of manufacture (in the present embodiment, at the time of molding), the relationship between the time of manufacture (at the time of molding) and each lot ID is required. This necessitates linking, and management becomes complicated. However, in the present embodiment, there is no such need, and management with traceability can be more easily performed.

Finally, a method for inspecting the diffractive optical element 1 will be described.
In the diffractive optical element 1, first, individual optical performances are inspected in the form of the multi-faced body 500. In the state of the multi-faced body 500, the position and the orientation of the diffraction grating 10 in the diffractive optical element 1 are stable, and the inspection of each diffractive optical element 1 can be performed continuously, and the accuracy and efficiency of the inspection are improved. Very good. More specifically, each diffractive optical element 1 is irradiated with inspection light, the projection pattern is photographed, and it is determined by image analysis whether or not the projection pattern is appropriately projected. This is automatically and sequentially performed, so that the optical performance of all the diffractive optical elements 1 is inspected.

  After the inspection of the optical performance, the multi-faced body 500 is cut into individual pieces and further housed in the housing member 600 in a predetermined number. In this process, there is a possibility that a defect that has not occurred during the inspection of the optical performance is generated. In particular, in the cutting step, there is a high possibility that cutting chips and the like generated at the time of cutting adhere to the diffractive optical element 1. Therefore, it is desirable to further inspect the diffractive optical element 1 housed in the housing member 600.

  However, as shown in FIG. 12, the receiving portion 601 of the receiving member 600 is formed slightly larger than the outer shape of the diffractive optical element 1 in order to reliably receive the diffractive optical element 1. Therefore, the position and the orientation of the diffractive optical element 1 in the accommodation section 601 are undefined. Even in such a state, if a dedicated inspection device is developed and manufactured, the inspection can be automatically performed. However, depending on the number of the diffractive optical elements 1 to be manufactured, the development cost of the diffractive optical element 1 may be too high if a dedicated inspection device is developed and manufactured. In addition, an irregular defect that cannot be detected by the inspection pattern set by the inspection device or an exceptional defect may occur. In such a case, a visual inspection by an inspector is often more suitable. Therefore, in the present embodiment, a final visual inspection is performed with the diffractive optical element 1 housed in the housing member 600. In this visual inspection, an inspector performs a magnified observation using a microscope to inspect at least for the presence of foreign matter.

FIG. 13 is a diagram for explaining the foreign substance inspection.
In the diffractive optical element 1 of the present embodiment, when a foreign substance P is observed at the time of foreign substance inspection, for example, as shown in FIG. 13, the defect sample 40 and the foreign substance P can be compared and observed within the same visual field of the microscope. Yes, the visual inspection can be performed accurately and easily.
Here, since the diffractive optical element 1 of the present embodiment is housed in a plurality of housing members 600 in a predetermined number, the inspection can be performed simultaneously (in parallel) by a plurality of inspectors. It is. Therefore, the inspection process can be performed in a short time. When the inspection is performed by a plurality of inspectors, the defect sample 40 is provided, so that a variation in the inspection accuracy by the inspectors can be suppressed, and a stable and high-accuracy inspection can be realized.

As described above, since the diffractive optical element 1 according to the present embodiment includes the type identification code 20 and the position identification code 30, the traceability of each manufactured product can be ensured.
Further, the diffractive optical element 1 is accommodated in the accommodating member 600 in a predetermined number, and a unique lot ID is given for each molding, so that the convenience in using the diffractive optical element 1 is impaired. Without compromising traceability.
Further, since the diffractive optical element 1 includes the defect sample 40, the accuracy of the visual inspection by the inspector can be improved, and the inspection can be easily performed.
Furthermore, since the defect sample 40 has a plurality of defect samples 40a, 40b, and 40c having different dimensions arranged side by side, the size of the observation target can be easily grasped.

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

(1) In the embodiment, the defect sample 40 has been described as an example in which the defect sample 40 is provided at one place. For example, the defect sample 40 may be provided at a plurality of locations. In particular, when the magnification of the microscope is large and the observation visual field is narrow, a plurality of defect samples 40 may be arranged so as to be surely included in the observation visual field.

(2) In the embodiment, the visual inspection has been described as inspecting the adhesion of foreign matter. However, the molding defect may be inspected by comparing it with the defect sample 40.

(3) In the embodiment, the example in which the defect sample 40 has the same shape is described. However, the present invention is not limited to this. For example, a plurality of types of defect samples 40 having different shapes may be arranged. For example, in addition to a square, a rectangular defect sample and a circular defect sample may be arranged. In such a case, it is desirable to unify the area of the defect sample rather than unify the length. This is because, as a defect of the diffraction grating, the area element is more dominant in the optical characteristics than the length element. Therefore, for example, the area of each of the square, rectangular, and circular defect samples may be the same.

  The embodiments and the modified embodiments can be used in appropriate combinations, but detailed description is omitted. Further, the present invention is not limited by the embodiments described above.

Reference Signs List 1 diffractive optical element 1a base material 1b resin layer 10 diffraction grating 11 high refractive index portion 11a convex portion 11b side wall portion 12 concave portion 13 space 14 low refractive index portion 15 diffraction layer 20 type identification code 30 position identification code 40, 40a, 40b, 40c Defect sample 50 Cutting position mark 200 Screen 201 Light 202 Irradiation area 204 Irradiation area 210 Light source section 500 Multi-faced body 600 Housing member 601 Housing section 602 Lot ID display section

Claims (6)

A substrate,
A resin layer formed on the base material,
A diffractive optical element comprising
The resin layer has a shaping shape corresponding to the shape formed in the mold,
The shaped shape,
A diffraction grating;
A type identification code for identifying the molding die,
A position identification code for identifying the position of the diffractive optical element in the mold,
A diffractive optical element comprising: The diffractive optical element according to claim 1,
The shaping shape includes a defect sample formed to a predetermined size,
A diffractive optical element characterized by the above-mentioned. The diffractive optical element according to claim 2,
The defect sample, a plurality of defect samples having different dimensions are arranged side by side,
A diffractive optical element characterized by the above-mentioned.   A multi-faced body of a diffractive optical element, wherein the diffractive optical element according to any one of claims 1 to 3 is multi-faced. A method for managing a diffractive optical element according to any one of claims 1 to 3, wherein
A unique lot ID is set for each molding of the multi-faced body of the diffractive optical element,
Cutting the multi-faced body into individual diffractive optical elements,
The cut diffractive optical element is housed separately in a plurality of housing members,
Applying the lot ID set for each molding to all of the storage members,
How to manage diffractive optical elements. A method for inspecting a diffractive optical element according to any one of claims 1 to 3,
The diffractive optical element is molded in the form of a multi-faced multi-faced body,
Perform at least optical performance inspection in the state of the multi-faced body,
Cutting the multi-faced body into individual diffractive optical elements,
The cut diffractive optical element is housed separately in a plurality of housing members,
Inspection of at least foreign matter is carried out in a state accommodated in the accommodation member,
Inspection method for diffractive optical element.

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