JP2019101442A - Light irradiation device, manufacturing method of light irradiation device, diffraction optical element polygon assembly, manufacturing method of diffraction optical element polygon assembly, diffraction optical element, and manufacturing method of diffraction optical element - Google Patents

Abstract

To provide a light irradiation device easy to manufacture and capable of improving optical characteristics, and also to provide a manufacturing method of a light irradiation device, a diffraction optical element polygon assembly, a manufacturing method of a diffraction optical element polygon assembly, a diffraction optical element, and a manufacturing method of a diffraction optical element.SOLUTION: A light irradiation device 1 includes: a light source part 20; and a diffraction optical element 10 arranged at a location to be irradiated with light from the light source part 20 and including a unit cell 17 of a rectangular shape having a plurality of diffraction gratings to obtain specific light distribution characteristics. The diffraction optical element 10 includes a plurality of the unit cells 17 periodically arranged. The diffraction gratings are formed to an end part of the diffraction optical element 10.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a light irradiation apparatus, a method of manufacturing a light irradiation apparatus, a diffractive optical element polyhedron, a method of manufacturing a diffractive optical element polyhedron, a diffractive optical element, and a method of manufacturing a diffractive optical element.

  Conventionally, in the field of camera modules and the like, technologies such as WLO (Wafer Level Optics) and WLP (Wafer Level Package) have been developed. The technologies such as WLO and WLP are based on a refractive lens as an optical element, and if the optical axis alignment with the light source and the sensor unit is not performed, the performance is not sufficiently exhibited and the module chip size does not function properly. It is common practice to make multiple interviews each time.

  In the above-mentioned prior art, since multiple faces are provided for each module chip size, positioning of the light source or sensor member with the optical element becomes important. In particular, when the light source or the sensor member and the optical element are bonded to each other, if there is a pitch deviation from one end to the other of the polyhedron, there is a possibility that a part where the optical axis is not aligned is generated, which may lead to yield deterioration.

  In addition, when there is a positional deviation between the lens area formed in the optical element and the light source, light from the light source is in the area where there is no lens deflection action or in the area having a deflection action different from the original lens deflection action. There was a case where the desired light distribution characteristic could not be obtained for the light which has been irradiated and passed through the optical element.

  Therefore, it is necessary to make the process of positioning complicated, or to improve the dimensional accuracy of each member. These are factors of cost increase, and improvement has been desired.

In addition, in WLO, WLP, etc., cutting is performed in order to singulate into chip sizes. The dust generated at the time of cutting degrades the performance of the optical element, and it has been desired to suppress the generation of the dust. In particular, in the case of a diffractive optical element (DOE) which is an optical element provided with a diffraction grating, if the diffraction grating is constituted by a fine asperity shape, dust may be generated at the time of cutting and adhere to the asperity shape, Since removal is difficult and the influence on optical properties is large, there has been a demand for a method that can be easily manufactured by suppressing the generation of dust at the time of cutting.
Also, in recent years, PLP (Panel Level Package) technology has been developed as a technical method to replace WLO, WLP, etc. However, as with WLO, WLP, etc., cutting to separate into chip sizes is necessary. There is a need to control dust generation as well.

JP 2003-302526 A

  The object of the present invention is to provide a light irradiation apparatus which can be easily manufactured and whose optical characteristics can be improved, a method of manufacturing the light irradiation apparatus, a diffractive optical element polyhedron, a diffractive optical element polyhedron, a diffraction An optical element and a method of manufacturing a diffractive optical element are provided.

  The present invention solves the above problems by the following solution means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached and demonstrated, it is not limited to this.

  According to the first aspect of the present invention, a light source (20, 21) and a position where light from the light source (20, 21) is irradiated are disposed to form a plurality of diffraction gratings to obtain specific light distribution characteristics. And a diffractive optical element (10) having a rectangular unit cell (17), wherein the diffractive optical element (10) is configured by arranging a plurality of the unit cells (17) periodically. It is a light irradiation device (1, 1B) in which the diffraction grating is formed up to the end of the diffractive optical element (10).

  A second invention is characterized in that, in the light irradiation apparatus (1, 1B) according to the first invention, the diffraction grating pattern is continuous at the boundary portion where the unit cells (17) are adjacent to each other. Light irradiator (1, 1B).

  A third invention is the light irradiation device (1, 1B) according to the first invention or the second invention, wherein the diffractive optical element (10) is a mark (16) distinguishable from a diffraction grating. And a light irradiator (1, 1B).

  A fourth invention is characterized in that, in the light irradiation device (1, 1B) according to the third invention, the mark (16) is disposed so as to overlap a region where the diffraction grating is disposed. It is a light irradiation device (1, 1 B).

  In a fifth aspect of the present invention, in the light irradiation device (1, 1B) according to any one of the first to fourth aspects, the unit cell (17) is irradiated from the light source (20, 21). It is a light irradiator (1, 1B) characterized in that it has a size that can be arranged in a plurality in the irradiation range of light.

  A sixth invention is the light irradiation apparatus (1, 1B) according to any one of the first invention to the fifth invention, wherein the unit cell (17) has a normal to the surface on which the concavo-convex shape is formed. A light irradiation device (1, 1) characterized in that a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments is formed when viewed from the direction, the boundary between the convex portion and the concave portion 1B).

  A seventh invention is the light irradiation apparatus (1, 1B) according to any of the first invention to the sixth invention, wherein at least the diffraction grating is formed in the diffractive optical element (10). It is a light irradiator (1, 1B) characterized by having a chamfer (18) at an end on the surface side.

  An eighth invention is the light irradiation apparatus (1, 1B) according to the seventh invention, wherein the diffractive optical element (10) includes a base material (12) made of glass, and the chamfered portion (18) ) Is a light irradiation device (1, 1B) characterized in that it is formed to at least a position where it reaches the base material (12).

  A ninth invention is the light irradiation apparatus (1, 1B) according to the seventh invention or the eighth invention, wherein the chamfered portion (18) is provided on both surfaces of the diffractive optical element (10). A light emitting device (1, 1B) characterized by

  The tenth invention is a light source multifaceted body (200) in which a plurality of light sources (20, 21) are arranged side by side, and a rectangle configured such that a plurality of diffraction gratings are formed to obtain a specific light distribution characteristic. A plurality of unit cells (17) of a shape are arranged side by side, and a plurality of the unit cells (17) are periodically arranged, and the unit cells (17) are to be cut and separated into pieces A bonding step of bonding the diffractive optical element polyhedral body (100) continuously arranged regardless of the region, the light source polyhedral body (200) bonded in the bonding step, and the diffractive optical element polyhedron And a cutting step of cutting the body (100).

  In an eleventh aspect of the present invention, in the method of manufacturing a light irradiation device (1, 1B) according to the tenth aspect, the diffraction grating pattern is continuous at the boundary portion where the unit cells (17) are adjacent to each other. It is a manufacturing method of the light irradiation apparatus (1, 1B) characterized by these.

  The twelfth invention is the method for manufacturing a light irradiation device (1, 1B) according to the tenth invention or the eleventh invention, wherein the diffractive optical element polyhedron (100) is recognized separately from a diffraction grating. It is a method of manufacturing a light emitting device (1, 1B) characterized in that it comprises possible marks (16).

  In a thirteenth aspect of the present invention, in the method of manufacturing a light irradiation device (1, 1B) according to the twelfth aspect, the mark (16) is disposed so as to overlap the region where the diffraction grating is disposed. It is a manufacturing method of the light irradiation device (1, 1B) which is characterized.

  A fourteenth invention is characterized in that, in the method of manufacturing the light irradiation device (1, 1B) according to the thirteenth invention, the cutting step determines the cutting position using the mark (16). It is a manufacturing method of the light irradiation device (1, 1B) which

  The fifteenth invention is the method for manufacturing a light irradiation device (1, 1B) according to any of the tenth invention to the fourteenth invention, wherein the unit cell (17) comprises the light source (20, 21) It is a manufacturing method of the light irradiation apparatus (1, 1B) characterized by being a size which can be arranged in multiple numbers in the irradiation range of the light irradiated from.

  The sixteenth invention is the method of manufacturing a light irradiation device (1, 1B) according to any of the tenth invention to the fifteenth invention, wherein the unit cell (17) has a surface on which a concavo-convex shape is formed. A light irradiation apparatus characterized in that a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments is formed when viewed from the normal direction of It is a manufacturing method of (1, 1 B).

  The seventeenth invention is the manufacturing method of the light irradiation device (1, 1B) according to any one of the tenth invention to the sixteenth invention, wherein the cutting step is a surface on which at least the diffraction grating is formed. It is a manufacturing method of the light irradiation apparatus (1, 1B) characterized by including the chamfering part formation process of forming a chamfering part (18) in the side.

  The eighteenth invention is the manufacturing method of the light irradiation device (1, 1B) according to the seventeenth invention, wherein the diffractive optical element multifaceted body (100) includes a base material (12) made of glass. In the chamfered portion forming step, the chamfered portion (18) is formed to a position at least reaching the base (12), which is a manufacturing method of the light irradiation device (1, 1B).

  The nineteenth invention is the method for manufacturing a light irradiation device (1, 1B) according to the seventeenth invention or the eighteenth invention, wherein in the chamfered portion forming step, the joined light source multifaceted body (200) and A light irradiation apparatus characterized in that processing is performed from both sides of the diffractive optical element polyhedron (100) so as to form the chamfers (18) on both sides of the diffractive optical element polyhedron (100). It is a manufacturing method of (1, 1 B).

  The twentieth invention is the method according to any one of the seventeenth invention to the nineteenth invention, wherein in the chamfered portion forming step, the light source polyhedron (200) And at least one side of the diffractive optical element polyhedral body (100) is connected without being separated, and the light source polyhedral body (200) and the diffractive optical element polyhedral body ( 100) is a manufacturing method of the light irradiation device (1, 1B) characterized by including a main cutting step of cutting into pieces.

  In the twenty-first invention, a plurality of rectangular unit cells (17) configured to obtain a specific light distribution characteristic by forming a plurality of diffraction gratings are arranged side by side, and the unit cell (17) is A plurality of the diffractive optical element polyhedrons (100) are periodically arranged and configured, and the unit cells (17) are continuously arranged irrespective of the area to be cut and separated into pieces It is.

  The twenty-second invention is characterized in that, in the diffractive optical element polyhedron (100) according to the twenty-first invention, the pattern of the diffraction grating is continuous at the boundary portion where the unit cells (17) are adjacent to each other. It is a diffractive optical element polyhedron (100).

  The twenty-third invention is the diffractive optical element multifaceted body (100) according to the twenty-first invention or the twenty-second invention, comprising a mark (16) distinguishable from the diffraction grating, and the mark (16) Is a diffractive optical element multifaceted body (100) characterized in that the diffractive optical element is disposed so as to overlap the area where the diffraction grating is disposed.

  The twenty-fourth invention is characterized in that, in the diffractive optical element polyhedron (100) according to the twenty-third invention, the marks (16) are arranged for every planned cutting straight line where cutting is scheduled. Diffractive optical element polyhedron (100).

  The twenty-fifth invention is the diffractive optical element multifaceted body (100) according to the twenty-third invention or the twenty-fourth invention, wherein the mark (16) is arranged for each area to be cut and separated into pieces It is a diffractive optical element polyhedron (100) characterized in that

  According to a twenty-sixth aspect, in the diffractive optical element multifaceted body (100) according to any one of the twenty-first to twenty-fifth aspects, a unit cell (17) has a surface with a concavo-convex shape formed thereon. A diffractive optical element multifaceted characterized in that a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments is formed as viewed from the linear direction. It is a body (100).

  In a twenty-seventh aspect of the present invention, a plurality of rectangular unit cells (17) configured such that a plurality of diffraction gratings are formed to obtain a specific light distribution characteristic are arranged side by side, and the unit cell (17) is A manufacturing method of a diffractive optical element polyhedral body (100) for manufacturing a diffractive optical element polyhedral body (100) which is periodically arrayed and configured, and a region in which a diffraction grating is formed is divided into a plurality of areas. Forming a diffraction grating by using a mold preparing step of preparing a mold (300, 401, 402, 403) corresponding to the divided area, and using the mold (300, 401, 402, 403) A process for producing a diffractive optical element polyhedron (100) comprising the steps of:

  The twenty-eighth invention is a manufacturing method of a diffractive optical element polyhedron (100) according to the twenty-seventh invention, wherein the shaping step uses the same molding die (300, 401, 402, 403). A method of manufacturing a diffractive optical element multifaceted body (100), comprising the step of sequentially forming different regions.

  The twenty-ninth invention is the manufacturing method of a diffractive optical element multifaceted body (100) according to the twenty-seventh invention or the twenty-eighth invention, wherein the unit cell (17) has a normal to a surface on which a concavo-convex shape is formed. A diffractive optical element having a pattern in which a boundary between a convex portion and a concave portion includes at least one of a curved line and a broken line connecting a plurality of line segments as viewed from the direction is formed. It is a manufacturing method of (100).

  The thirtieth invention has a rectangular unit cell (17) configured to have a plurality of diffraction gratings formed to obtain a specific light distribution characteristic, and the diffraction gratings are formed up to the end. It is a diffractive optical element (10) having a chamfered portion (18) at least at the end on the side where the diffraction grating is formed.

  According to a thirty-first aspect of the present invention, in the diffractive optical element (10) according to the thirtieth aspect, the unit cell (17) has a boundary between the convex portion and the concave portion when viewed from the normal direction of the surface on which the concave and convex shape is formed A diffractive optical element (10) is characterized in that a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments is formed.

  The thirty-second invention comprises the substrate (12) made of glass in the diffractive optical element (10) according to the thirtieth invention or the thirty-first invention, and the chamfered portion (18) comprises at least the base It is a diffractive optical element (10) characterized in that it is formed to a position where it reaches the material (12).

  The thirty-third invention is the diffractive optical element (10) according to any of the thirtieth invention to the thirty-second invention, wherein the chamfered portion (18) is provided on both surfaces of the diffractive optical element (10). It is a diffractive optical element (10) characterized by being.

  The thirty-fourth invention is a method of manufacturing the diffractive optical element (10) according to any of the thirtieth invention to the thirty-third invention, wherein a plurality of diffraction gratings are formed to obtain a specific light distribution characteristic. A plurality of unit cells (17) of a rectangular shape configured to be arranged side by side, and a plurality of the unit cells (17) are periodically arranged, and the unit cells (17) are cut And a cutting step of cutting the diffractive optical element multifaceted body (100) continuously arranged regardless of the area to be singulated, the cutting step forming at least the diffraction grating This is a method of manufacturing a diffractive optical element (10) including a chamfered portion forming step of forming a chamfered portion (18) at an end portion on the side where the lens is located.

  According to the present invention, it is possible to provide a light irradiation device which can be easily manufactured and whose optical characteristics can be improved, a method of manufacturing the light irradiation device, a diffractive optical element polyhedron, and a method of manufacturing the diffractive optical element polyhedron. can do.

It is a disassembled perspective view of the light irradiation apparatus 1 of 1st Embodiment. FIG. 2 is a perspective view of the light irradiation device 1; FIG. 2 is a cross-sectional view of the light irradiation device 1; FIG. 4 is a plan view of the diffractive optical element 10 as viewed from above in FIG. 3. It is the figure which abbreviate | omitted and showed the pattern of the diffraction grating from FIG. It is the figure which showed only the pattern of the diffraction grating from FIG. It is a perspective view which shows an example of the partial period structure in the example of the unit cell 17 of FIG. FIG. 2 is a cross-sectional view schematically showing a diffractive optical element. FIG. 2 is a view showing a diffractive optical element wafer 100 and a light source wafer 200 used for manufacturing the light irradiation device 1. FIG. 6 is a view showing a state in which the diffractive optical element wafer 100 and the light source wafer 200 are bonded as a cross section. It is a figure explaining an example of imprint formation. It is a figure explaining the other example of imprint molding. It is sectional drawing of light irradiation apparatus 1B of 2nd Embodiment. It is a figure which shows the cutting process which cut | disconnects in the state which joined the diffractive optical element wafer 100 and the light source wafer 200. FIG. It is a figure which shows the cutting process which cut | disconnects in the state which joined the diffractive optical element wafer 100 and the light source wafer 200. FIG. It is sectional drawing of the diffraction optical element 10 of 3rd Embodiment. It is a figure which shows the cutting process which cut | disconnects the diffractive optical element wafer 100. FIG. It is a figure which shows the example which performs formation and singulation of the chamfering part 18 using only the rotary blade whose V-shaped tip. It is a figure which shows the test condition of a 4 point | piece bending test. It is sectional drawing which cut | disconnected three types of test pieces in the position of arrow AA in FIG. It is the figure which put together and showed experimental conditions and an experimental result. It is a graph which shows the relationship between the angle of the chamfer and the maximum bending stress obtained from the experimental result. It is a figure which shows the photograph which image-photographed the end surface which actually cut | disconnected the diffractive optical element. It is a figure explaining the dimension of the chamfer 18.

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

First Embodiment
FIG. 1 is an exploded perspective view of the light irradiation device 1 of the first embodiment.
FIG. 2 is a perspective view of the light irradiation device 1.
FIG. 3 is a cross-sectional view of the light irradiation device 1.
Note that each of the drawings shown below including FIGS. 1 to 3 is a schematic view, and the size and shape of each part are appropriately exaggerated for easy understanding.
Moreover, in the following description, although a specific numerical value, a shape, a material, etc. are shown and demonstrated, these can be changed suitably.

In the present specification, terms specifying shape and geometrical conditions, such as parallel and orthogonal terms, in addition to strictly meaning, have similar optical functions and can be regarded as parallel or orthogonal. It also includes conditions with errors.
In this specification, the terms plate, sheet, film, etc. are used, but as a general usage, these are used in the order of thickness, in order of plate, sheet, film I use it according to it even in writing. However, there is no technical meaning to such proper use, and these terms can be replaced as appropriate.
In the present invention, the term "transparent" refers to one that transmits light of at least the wavelength to be used. For example, even if it does not transmit visible light, if it transmits infrared light, it shall be treated as transparent when used for infrared applications.

As shown in FIG. 1, the light irradiation device 1 includes a diffractive optical element 10 and a light source unit 20.
The light irradiation apparatus 1 of the present embodiment may, for example, irradiate and use an irradiation pattern representing a barcode, or may irradiate an irradiation pattern representing various information from a vehicle or the like to a road surface or the like. Further, the light irradiation device 1 may be used for irradiation of detection light in distance measurement, human body detection, three-dimensional object recognition or the like. In addition, the light irradiation device 1 may be integrated with a device that takes in reflected light from an object with a camera or the like, in which case distance measurement, 3D recognition, human body measurement, object recognition, and bar recognition are possible.

The diffractive optical element (optical element) 10 is an element called DOE that shapes light by controlling the traveling direction of light by diffraction phenomenon, and is formed in a plate shape.
In the present invention, “to shape the light” means that the shape (irradiation pattern) of the light projected onto the object or the target area becomes an arbitrary shape by controlling the traveling direction of the light. It means to flatten the intensity distribution in the irradiation pattern, or to make the intensity distribution as a whole or partially. For example, when the light source is directly projected onto a planar-shaped diffractive optical element, light whose illumination spot is circular is emitted. By transmitting this light through a diffractive optical element, it is called “shaping the light” to make the irradiation pattern a desired shape such as a combination of squares, a rectangle, a circle and the like.

The diffractive optical element 10 includes a high refractive index portion 11, a base 12, and an adhesive layer 13, and is disposed at a position where light from the light source portion 20 is irradiated.
The high refractive index portion 11 uses, for example, an ultraviolet curable resin coated on a base material to form a concavoconvex shape by using an original plate on which a concavoconvex shape corresponding to a diffraction grating is formed, transfers the concavoconvex shape, and irradiates ultraviolet light. It can be formed by curing.

  As an ultraviolet curing resin, urethane acrylate type, polyester acrylate type, epoxy acrylate type, polyether acrylate type, polythiol type, butadiene acrylate etc. can be used, for example. In addition, the material for forming the high refractive index part 11 is not limited to an ultraviolet curing resin. The high refractive index portion 11 may be formed of, for example, an electron beam curable resin. Further, the high refractive index portion 11 may be configured using a thermosetting or ultraviolet curable SOG (Spin on Glass). Further, the concavo-convex shape corresponding to the diffraction grating is not limited to the example of transferring from the original plate by molding, and the concavo-convex shape may be shaped using an intermediate plate of a resin manufactured from the original plate having the concavo-convex shape.

The base 12 is a member serving as a base when forming the high refractive index portion 11. For example, glass can be used as the substrate 12. Further, the substrate 12 is not limited to glass, and polycarbonate (PC) resin, polyethylene terephthalate (PET) resin, methyl methacrylate butadiene styrene (MBS) resin, methyl methacrylate styrene (MS) resin, acrylic Transparent resins such as styrene (AS) resin and acrylonitrile butadiene styrene (ABS) resin can be used. In the present embodiment, glass is used as the substrate 12 and thus the plate 12 is formed, but a resin sheet or a resin film may be used.
The adhesion layer 13 is a primer layer which is applied on the substrate 12 to enhance the adhesion to the ultraviolet curable resin or the like. The adhesion layer 13 may be omitted.
Details of the diffractive optical element 10 will be described later.

The light source unit 20 includes a light emitting element (light source) 21, a substrate 22, and a holder 24.
The light emitting element (light source) 21 emits infrared light, blue light or the like, and projects the light onto the diffractive optical element 10. As the light emitting element 21, for example, a laser light source such as a vertical cavity surface emitting laser (VCSEL) may be used, or an LED (light emitting diode) may be used. The light emitting element 21 is mounted on the substrate 22. Note that, depending on the form of the light-emitting element 21, the wiring 23 can be used to connect to the substrate. In the present embodiment, the light emitting element 21 is a vertical cavity surface emitting laser that emits light having a wavelength of 850 nm.

The holder 24 is formed in a frame shape for mounting the diffractive optical element 10. The holder 24 is formed of, for example, an engineering plastic such as polyamide or polycarbonate. In order to make the holder 24 difficult to deform, it is possible to contain glass fiber in polycarbonate or the like.
The center of the holder 24 is an opening that penetrates. The holder 24 has a top 24 a on which the peripheral edge of the diffractive optical element 10 is placed. Then, the diffractive optical element 10 is mounted on and fixed to the top 24 a via the adhesive 60. In addition, although the top part 24a of the holder 24 of this embodiment is comprised by the plane, you may provide a groove | channel further.
The holder 24 is attached to the substrate 22 on the back side (the lower side in FIG. 3) using an adhesive (not shown) or the like.

FIG. 4 is a plan view of the diffractive optical element 10 as viewed from above in FIG.
FIG. 5 is a view in which the pattern of the diffraction grating is omitted from FIG.
Marks 16 are arranged at a plurality of places on the surface of the diffractive optical element 10. In the present embodiment, the mark 16 is disposed so as to overlap the area where the pattern of the diffraction grating is disposed.

The mark 16 is used as, for example, various marks or references for detection using an optical detection device.
The mark 16 is formed of a collection of patterns having a plurality of concavo-convex shapes, and can be easily recognized optically by reflection of light by the edges of the concavities and the like. As the concavo-convex shape, for example, a line and space pattern, a hole pattern, a dot pattern or the like can be used. With regard to the concavo-convex shape, one of them may be used to form a set of patterns, or a plurality of types may be used to form a set of patterns. The irregular shape of these patterns can have a certain periodicity.

Assuming that the combined width of a pair of adjacent concave and convex portions forming the mark 16 is a pitch, the pitch of the concave and convex shape forming the mark 16 is particularly limited as long as detection is easy by the optical detection device. It is not done. For example, by making the pitch of the concavo-convex shape wider than the pitch of the pattern of the diffraction grating described later, the manufacturing of the diffractive optical element 10 is not hindered. In addition, the smaller the pitch, the easier the detection due to the reflection of light at the edge portion of the uneven shape. For example, it may be set at a pitch of about 500 nm to 10 μm, more preferably 1 μm to 5 μm. Moreover, multiple types of pitch may be included.
The duty ratio, which is the ratio of the width of each set of concave and convex portions, may be 1: 1 which is easy to detect in the optical detection device, but may be changed within the range that can be manufactured.
In the present embodiment, the marks 16 are all formed as line and space patterns in the same direction in accordance with the direction of molding. The pitches of the concave and convex portions are all constant, and the duty ratio is 1: 1.
Further, the maximum depth of the recess of the mark 16 is preferably equal to or deeper than the maximum depth of the diffraction grating. As the recess of the mark 16 is made deeper, identification becomes easier.
If the detection accuracy of the mark 16 is reduced due to the specifications of the device forming the diffractive optical element 10, the mark 16 may be made of another reflective or light-shielding material instead of the concavo-convex structure. Although a general method such as photolithography can be employed, photolithography is preferably used when metal or the like is used. The diffractive optical element 10 is formed on the front surface or the back surface of the substrate 12.

Next, the pattern of the diffraction grating provided in the diffractive optical element 10 will be described in more detail.
FIG. 6 is a view showing only the pattern of the diffraction grating from FIG.
In the diffractive optical element 10, a plurality of unit cells 17 are periodically arranged. The unit cell 17 is configured such that a plurality of diffraction gratings are formed to shape specific light distribution characteristics, that is, light into a desired pattern. For this reason, a diffraction grating configured in a concavo-convex shape is designed and arranged on the high refractive index portion 11 so that desired light distribution characteristics can be obtained with only the unit cell 17. The plurality of unit cells 17 all have the same configuration of the diffraction grating, and a plurality of unit cells 17 having the same concavo-convex shape (diffraction grating) are arranged side by side.
Further, the unit cells 17 are arranged without a gap, and the diffraction grating pattern is set to be continuous at the boundary where the unit cells are adjacent to each other.
Furthermore, the diffraction grating is formed without providing a margin and the like up to the end of the diffractive optical element 10.
In the present embodiment, one diffractive optical element 10 is formed in a square of 3 mm × 3 mm, and the unit cell 17 is set in a square of 0.6 mm × 0.6 mm. Thus, 25 unit cells 17 are arranged on the surface of the diffractive optical element 10.

  The light emitting element 21 emits light to the diffractive optical element 10, and the irradiated area may be the entire surface of the diffractive optical element 10, but usually, for example, about 50% of the element area of the diffractive optical element 10 About 80%. A plurality of unit cells 17 are arranged in the irradiation area of the light. For example, even if the irradiation area of light is 50% of the element area of the diffractive optical element 10, in the example of the present embodiment, 12.5 unit cells 17 are arranged. Further, in the diffractive optical element 10 of the present embodiment, the diffraction gratings are arranged on the entire surface. Therefore, even if there is a relative positional deviation between the diffractive optical element 10 and the light emitting element 21, the light irradiation device 1 of the present embodiment can always emit light shaped appropriately.

  In FIG. 6, the unit cell 17 is shown to be large for easy understanding, and an example in which nine unit cells 17 are disposed in one diffractive optical element 10 is shown. In addition, although the boundaries of the unit cells 17 are intentionally expressed in an easy-to-understand manner so that the unit cells 17 can be easily understood, in fact, in the boundaries of the unit cells 17, the diffraction grating pattern is continuous. Because it is difficult to distinguish.

  The unit cells 17 of the present embodiment have different depths at the positions of the different hatching regions shown in FIG. That is, the unit cell 17 is comprised by the multistep shape from which the height of four steps differs. The unit cell 17 usually has a plurality of regions (partial periodic structures) having different periodic structures.

FIG. 7 is a perspective view showing an example of a partial periodic structure in the example of the unit cell 17 of FIG.
FIG. 8 is a cross-sectional view schematically showing the diffractive optical element.
The pattern of the diffraction grating formed in the unit cell 17 is formed by a curve, but it is a broken line in which straight line segments or curved line segments are connected depending on the target emission pattern of the diffractive optical element. May contain patterns. Therefore, in the diffraction grating pattern of the present embodiment, the boundary between the convex portion and the concave portion has a curve and a plurality of line segments when viewed from the normal direction of the surface on which the concavo-convex shape of the high refractive index portion 11 (described later) is formed. Includes at least one of the connected polygonal lines.
Although the diffractive optical element 10 has a complicated shape as shown in FIG. 7, when simplified and schematically shown, as shown in FIG. 8, a plurality of convex portions 11a are arranged side by side in the cross sectional shape The high refractive index portion 11 is provided.

The high refractive index portion 11 may be formed by processing a shape by etching quartz (SiO ₂ , synthetic quartz), for example. Further, the high refractive index portion 11 is obtained by forming a mold from a product obtained by processing quartz or a silicon wafer to form a mold, and curing the ionizing radiation curable resin composition using the mold. It is also good. Various methods are known for producing such a periodic structure using an ionizing radiation curable resin composition, and the high refractive index portion 11 of the unit cell 17 (diffractive optical element 10) is It can produce suitably using the method of.

  Further, air exists in the upper part of FIG. 8 including the recess 14 a formed between the protrusions 11 a and the space 14 b near the top of the protrusions 11 a, and the refractive index is higher than that of the high refractive index portion 11. Is a low refractive index portion 14. The periodic structure in which the high refractive index portions 11 and the low refractive index portions 14 are alternately arranged, constitutes a diffraction layer 15 having an action of shaping light.

The convex part 11a of this embodiment has a multistep shape provided with four step parts from which height differs on one side (left side in FIG. 8) of side shape. Specifically, the convex portion 11a has a level 1 step portion 11a-1 that protrudes the most, a level 2 step portion 11a-2 that is one step lower than the level 1 step portion 11a-1, and a level 2 step portion 11a-2 A level 3 step 11a-3, which is lower by one step, and a level 4 step 11a-4, which is lower by one step than the level 3 step 11a-3, are provided on one side. Moreover, the other side (right side in FIG. 8) of the side surface shape of the convex part 11a is the side wall part 11b connected linearly from level 1 step part 11a-1 to level 4 step part 11a-4.
In the light irradiation apparatus of the present embodiment, since the light emitting element 21 is a laser light source having a wavelength of 850 nm, the diffraction grating of the unit cell 17 is optimum for diffracting light having a wavelength of 850 nm. Is configured to be

  The partial periodic structure composed of the multistep shape as described above is mainly formed with the arrangement pitch and the arrangement direction being different for each partial periodic structure. In each partial periodic structure, light is diffracted, deflected in a predetermined direction, and emitted, and thus, in one partial periodic structure, light is irradiated as a very small point (dot). A large number of such partial periodic structures, each configured to deflect light in a desired direction, are disposed in each unit cell 17, and as a whole, it becomes possible to project an irradiation pattern in which light is shaped into a desired shape. ing.

Next, the manufacturing method of the light irradiation apparatus 1 of this embodiment is demonstrated.
In this embodiment, the light source unit 20 and the diffractive optical element 10 are not joined to each light irradiation apparatus 1, and a method called WLO (Wafer Level Optics) or WLP (Wafer Level Package) is further improved. Use.
FIG. 9 is a view showing a diffractive optical element wafer 100 and a light source wafer 200 used for manufacturing the light irradiation device 1.
FIG. 10 is a view showing a state in which the diffractive optical element wafer 100 and the light source wafer 200 are bonded as a cross section.
In the present embodiment, a diffractive optical element wafer 100 and a light source wafer 200 as shown in FIG. 9 are respectively manufactured.
Here, the diffractive optical element wafer 100 is a diffraction grating polyhedron with a plurality of unit cells arranged, and the light source wafer 200 is a light source polyhedron with a plurality of light sources arranged side by side. In the following description, the diffractive optical element wafer 100 and the light source wafer 200 of wafer shape (circular shape) generally used in WLO, WLP, etc. are described as an example. The shape of the body is not limited to the wafer shape (circular shape), and may be a square panel shape used in PLP (Panel Level Package) or the like.

In the manufacture of the diffractive optical element wafer 100 of the present embodiment, first, the adhesive layer 13 is applied on a circular glass substrate 12 having a diameter of 8 inches. Then, an uncured ultraviolet curable resin to be the high refractive index portion 11 is applied onto the adhesion layer 13, and an original plate (molding die) described later is pressed against this to irradiate ultraviolet rays in a state of forming the uneven shape. Then, the diffractive optical element wafer 100 is completed by curing.
Here, the diffraction grating formed on the diffractive optical element wafer 100 is configured by arranging a plurality of unit cells 17 periodically. The unit cells 17 on the diffractive optical element wafer 100 are continuously arranged regardless of the area to be cut and separated. That is, on the diffractive optical element wafer 100, with regard to the diffraction grating formed in the high refractive index portion 11, there is no distinction of the region to be cut and divided into pieces. However, the mark 16 is provided for each area to be cut and separated into pieces.
In the present embodiment, as in the region A indicated by hatching on the diffractive optical element wafer 100 of FIG. 9, the concavo-convex shape of the diffraction grating is formed only in the necessary region. However, the concavo-convex shape of the diffraction grating may be formed on the entire surface of the diffractive optical element wafer 100.

  For manufacturing the diffractive optical element wafer 100, as described above, an original plate having a concavo-convex shape of a diffraction grating is prepared in advance, imprint molding is performed using this original plate, and the concavo-convex shape is transferred to an ultraviolet curing resin ) To do. Since preparation of this original plate is very time-consuming and expensive, the preparation of the 8-inch original plate as described above is inefficient and impractical. Therefore, in the present embodiment, the 8-inch-sized diffractive optical element wafer 100 is divided into a plurality of regions, and a large-sized diffractive optical element wafer 100 is efficiently manufactured by using an original plate smaller than the entire size.

FIG. 11 is a view for explaining an example of imprint molding. The hatched area in FIG. 11 indicates the area in which the concavo-convex shape of the diffraction grating is disposed, and the original plate corresponding thereto.
In the example shown in FIG. 11, the surface of the diffractive optical element wafer 100 is divided into four regions, and an original plate (molding die) 300 corresponding to one of the regions is prepared (molding die preparation step). Then, using this original plate 300, a shaping step of shaping the diffraction grating is performed. This original plate 300 can be used for all four areas if it is rotated to change its orientation. Therefore, in this example, if one original plate 300 is prepared and the different regions are sequentially shaped using the same original plate 300, it is possible to manufacture the diffractive optical element wafer 100 larger than the original plate 300. In addition, four original plates 300 may be prepared and the entire shaping may be completed in one shaping step.
Note that although a slight gap is provided between the four divided regions in FIG. 11, this gap may be eliminated.

FIG. 12 is a view for explaining another example of imprint molding. The hatched area in FIG. 12 indicates the area in which the concavo-convex shape of the diffraction grating is arranged, and the original plate corresponding thereto.
In the example shown in FIG. 12, the surface of the diffractive optical element wafer 100 is divided into three types and twelve areas, and originals (forming molds) 401, 402, 403 corresponding to the types of the areas are prepared (forming mold preparation Process). Then, using this original plate 401, 402, 403, a shaping step of shaping the diffraction grating is performed. Since there are four regions corresponding to the originals 401, 402, and 403, respectively, each shaping may be sequentially performed, or four originals 401, 402, and 403 may be prepared to perform one application. It may be a mold process.
In FIG. 12, the 12 divided regions are closely arranged, but a slight gap may be provided between the respective regions.

  Returning to FIG. 9 and FIG. 10, the light source wafer 200 has a configuration in which the components to be the light source unit 20 are closely arranged. With respect to the boundaries of the portions to be the individual light source units 20 by being cut and separated, in the state of the light source wafer 200, there are no clear boundaries which are connected and a portion to be the wall of the holder 24 is configured ing.

Once the diffractive optical element wafer 100 and the light source wafer 200 described above are manufactured and prepared, a bonding step of bonding the both is performed. Specifically, an adhesive 60 is applied onto the top 24 a to bond the diffractive optical element wafer 100 and the light source wafer 200.
Next, a cutting process of cutting the diffractive optical element wafer 100 and the light source wafer 200 bonded in the bonding process is performed to singulate the light irradiation apparatus 1.

  Here, in the cutting step, cutting is performed at the position indicated by the arrow in FIG. 10, but it is very advantageous that the diffraction gratings formed on the diffractive optical element wafer 100 be arranged without distinction of the regions. work. That is, with regard to the cutting position of the diffractive optical element wafer 100, even if there is a slight positional deviation, the light shaping characteristic, that is, the light distribution characteristic of the light emitted from the light irradiation device 1 is not affected at all. . This is provided with a light shaping effect that can obtain the necessary light distribution characteristic only with the unit cell 17, and the unit cell 17 is sufficiently smaller than the irradiation area of the light from the light emitting element 21, and the irradiation area This is because a large number of unit cells 17 are arranged inside.

  Such a configuration is difficult to realize with a refractive lens, and when a conventional refractive lens is used, it is required that the optical axis of the lens be accurately aligned with the light emitting element 21. In addition, even if a diffractive optical element is used, in the conventional configuration in which the diffraction grating is provided only in the irradiation area, the occurrence of leaked light in unnecessary directions unless the alignment is made accurately, the reduction of the light utilization efficiency, etc. The phenomenon was happening. Therefore, conventionally, it has been necessary to accurately align the relative positions of the light emitting element side and the optical element (lens) side. For that purpose, the dimensions of both the diffractive optical element wafer 100 and the light source wafer 200 have to be very strictly controlled, and both have to be manufactured as high-precision parts.

  These problems are solved by the light irradiation device 1 of the present embodiment. Basically, with regard to relative positional deviation in the in-plane direction between the diffractive optical element wafer 100 and the light source wafer 200, only rough alignment is sufficient. Since the mark 16 is present on the diffractive optical element wafer 100, it is only necessary to prevent the mark from being largely deviated. Then, at the time of cutting, it is sufficient to adjust only the cutting position with respect to the light source wafer 200, and the labor of dimensional control required at the time of manufacturing can be greatly reduced. And although it is a structure which manufacture is easy in this way, deterioration of the optical characteristic by position shift does not occur easily, and as a result, the optical characteristic obtained can be improved.

In addition, unlike the positional deviation in the in-plane direction, the in-plane angular deviation needs to be adjusted in consideration of the required specifications, but it is usually sufficient to just match at least two marks at distant positions. Accuracy can be ensured. Also, physical alignment using a guide or the like is possible, and the management effort is small.
In addition, when using combining with another collimating lens element between a diffractive optical element and a light source, precise alignment with a lens and a light source (or light source wafer) is needed. Rough alignment of the diffractive optical element can be performed on elements for which precise alignment between the lens and the light source has already been made. If the diffractive optical element and the lens are aligned and combined first, they are formed on the lens Since the alignment mark thus obtained may be used for alignment with the light source, the alignment of the diffractive optical element and the lens can be roughly performed. In the latter case, the diffractive optical element and the lens can also be formed on both sides of the substrate.
When a pattern layer having a function other than diffraction is formed on either the front or the back of the base of the diffractive optical element 10, the pattern layer is viewed to design alignment with the light source or the collimating lens element. This enables rough alignment in the formation of the diffractive optical element. Examples of the pattern layer include a light shielding layer, an identification layer, and a wiring layer.

According to such a characteristic configuration of the present embodiment, in the cutting process, basically, the light source wafer 200 is used as a positioning reference to perform cutting at an equal pitch. The cutting may be performed based on the mark provided on the diffractive optical element wafer 100 or the light source wafer 200. In that case, the diffractive optical element wafer 100 may be further provided with a cutting mark. In this case, the mark may be arranged for each area to be cut and separated into pieces, or may be arranged for each planned cutting straight line for which cutting is scheduled. Also, this mark may be provided overlapping with the diffraction grating like the mark 16 shown above, or may be provided in the margin where the diffraction grating is not formed.
Even when marks are provided on the diffractive optical element wafer 100 and the cutting step is performed based on the marks, the advantageous effects of the above-described embodiment can be sufficiently exhibited. This is because the mark provided on the diffractive optical element wafer 100 may be used to indicate the position of the light source wafer 200 which is difficult to see when the diffractive optical element wafer 100 is bonded. In that case, it is preferable to grasp how much the mark provided on the diffractive optical element wafer 100 is deviated from the reference position of the light source wafer 200 at the time of bonding or before cutting.

  As described above, in the diffractive optical element 10 of the light irradiation apparatus 1 of the present embodiment, a plurality of unit cells 17 are periodically arranged, and a diffraction grating is formed up to the end of the diffractive optical element 10. ing. The unit cells 17 on the diffractive optical element wafer 100 are continuously arranged regardless of the area to be cut and separated. Therefore, high accuracy is not required for relative alignment between the diffractive optical element wafer 100 and the light source wafer 200 in the in-plane direction. In addition, alignment in the cutting process can be performed roughly. Thus, the manufacture can be facilitated, and the optical characteristics can be improved.

Second Embodiment
FIG. 13 is a cross-sectional view of the light irradiation device 1B of the second embodiment.
The light irradiation device 1B of the second embodiment differs from the light irradiation device 1 of the first embodiment in that the base material 12 is made of glass and in that the chamfered portion 18 is provided, It has the same form as the light irradiation device 1 of the first embodiment. Therefore, the same code | symbol is attached | subjected to the part which fulfill | performs the function similar to 1st Embodiment mentioned above, and the overlapping description is abbreviate | omitted suitably.

The base 12 of the light irradiation device 1B of the second embodiment is made of glass. By using glass as a base material, it is difficult to bend even if the thickness of the diffractive optical element 10 is reduced, and a diffractive optical element with high accuracy can be provided. On the other hand, since glass is generally brittle compared to a resin material, there is a high possibility that fine chips or the like may occur at the cut portion in the cutting step. If a missing portion occurs in the base 12, the strength of the diffractive optical element 10 may be degraded.
Moreover, as illustrated previously, the diffraction grating (high refractive index portion 11) of the diffractive optical element 10 has a very complicated shape, and this shape is very fine. Then, when cutting this complex and fine diffraction grating with a rotary blade, the high refractive index portion is peeled off due to the frictional force with the rotary blade or the like to become fine dust and adheres to the diffractive optical element 10 in large quantities. There is a fear. In particular, in the case where the base 12 is made of glass, when the glass is chipped, the risk of peeling off the diffraction grating is further increased.

  Therefore, in the light irradiation device 1B of the second embodiment, in the cutting step, the chamfered portion forming step of forming the chamfered portion 18 is performed to suppress the chipping of the glass base 12, and the diffraction grating (high refractive index The generation of dust caused by the part 11) is suppressed.

The chamfered portion 18 is on the surface side where the diffraction grating is formed, that is, on the surface side where the high refractive index portion 11 is provided, and in FIG. 13, the ridgeline of the end portion on the upper surface side (light emitting surface side) It has a C-chamfered shape. Accordingly, the chamfered portion 18 is configured as a slope. The chamfered portion 18 is formed on the entire periphery of the surface on which the high refractive index portion 11 is provided. In addition, the chamfered portion 18 is formed to a position where it reaches the base 12.
In the present embodiment, the chamfered portion 18 is a slope inclined 45 degrees with respect to the sheet surface of the diffractive optical element 10. Therefore, the bevel angle θ (half of the angle of the entire cutting edge, see FIG. 13) of the rotary blade B1 described later was 45 degrees.
The chamfered portion 18 is not limited to the C-chamfered but may be configured as a R-chamfered. In that case, the corresponding R-shaped one may be used also for the rotary blade B1.

FIG. 14 and FIG. 15 are views showing a cutting process of cutting in a state where the diffractive optical element wafer 100 and the light source wafer 200 are bonded.
In the cutting step of the second embodiment, first, as shown in FIG. 14, V-cut (bevel cut) is performed from the side where the high refractive index portion 11 is provided, using the rotary blade B1 having a V-shaped tip. , Forming the chamfered portion 18 (chamfered portion forming step). In this chamfered portion forming step, V cutting is performed to a position where the rotary blade B1 reaches the base material 12. At this stage, singulation is not performed, and the light source wafers 200 are in a connected state.

  Next, as shown in FIG. 15, a main cutting step is performed to cut the light source wafer 200 and the diffractive optical element wafer 100 into pieces using the rotary blade B2 narrower than the V-cut width. Thus, the light irradiation device 1B in which the chamfered portion 18 shown in FIG. 13 is formed in the diffractive optical element 10 is manufactured.

  As described above, first, the chamfered portion forming step of forming the chamfered portion 18 is performed, and then the main cutting step is performed, as compared with the case where the main cutting step is performed at one time as in the prior art. Effect is obtained.

  First, by forming the chamfered portion 18, generation of dust at the time of cutting can be significantly suppressed. In particular, it is possible to suppress the generation of dust due to part of the high refractive index portion 11 constituting the diffraction grating coming off and falling off. This is because, by using the rotary blade B1 having a V-shaped tip, the force of scraping from the deep part does not act on the high refractive index portion 11, and the force of pressing the high refractive index portion 11 from the cutting side acts It is presumed that the effect is obtained by

  Moreover, the chipping of the base 12 can be suppressed by forming the chamfered portion 18. This effect is particularly great when the substrate 12 is made of glass. This is because the chamfered portion 18 is formed to reach the base material 12 so that the end face becomes oblique even if a force to scrape from a deep part of the depth at the time of cutting of the base material 12 is generated on the end face of the base material 12 It is guessed that it is hard to lose it.

  Furthermore, by forming the chamfered portion 18, it is possible to improve the bending strength in the case where a force for bending the side on which the chamfered portion 18 is formed is applied to the base 12. This is an effect due to the fact that stress concentration does not occur because the above-described chipping of the substrate 12 is reduced.

Third Embodiment
FIG. 16 is a cross-sectional view of the diffractive optical element 10 of the third embodiment.
The diffractive optical element 10 according to the third embodiment includes the chamfered portion 18 and has the same configuration as the diffractive optical element 10 stacked in the light irradiation apparatus 1B according to the second embodiment described above.
In 2nd Embodiment, the example which formed the chamfer 18 in the light irradiation apparatus 1B was mentioned and demonstrated. The effect obtained by forming the chamfered portion 18 described in the second embodiment can not be obtained only when cutting a bonded piece of the diffractive optical element wafer 100 and the light source wafer 200. For example, also in the case of manufacturing the diffractive optical element 10 by cutting in the state of only the diffractive optical element wafer 100, the same effect as the second embodiment can be obtained as an effect by providing the chamfered portion 18 described above. .
The diffractive optical element 10 of the third embodiment is manufactured by performing a chamfered portion forming step in the cutting step of cutting from the diffractive optical element wafer 100 as in the second embodiment and then performing a main cutting step. It is possible. Then, the diffractive optical element 10 according to the third embodiment can significantly suppress the generation of dust at the time of cutting by providing the chamfered portion 18, and can suppress chipping of the base material 12. The strength can be improved.

Fourth Embodiment
FIG. 17 is a view showing a cutting step of cutting the diffractive optical element wafer 100. As shown in FIG.
In the fourth embodiment, a diffractive optical element 10 provided with chamfers 18 on both surfaces and a cutting process for manufacturing the same will be described.
In the fourth embodiment, the layer configurations of the diffractive optical element 10 and the diffractive optical element wafer 100 are different from those of the first to third embodiments. In the diffractive optical element 10 and the diffractive optical element wafer 100 of the fourth embodiment, the adhesive layer 13 provided in the first to third embodiments is omitted. In the diffractive optical element 10 and the diffractive optical element wafer 100 according to the fourth embodiment, the guarantee function layer 19 is provided on the surface of the base 12 on which the diffraction grating is not provided. The guarantee function layer 19 is a generic name of various layers to which an additional function can be given. The guarantee function layer 19 may be, for example, a protective film such as SiO _x or SION, may be an antireflective film, may be an ITO film, or any function may be added. In addition, the guarantee function layer 19 is not limited to a single layer, and a plurality of layers may be stacked.

In the example shown in FIG. 17, first, V-cut (bevel cut) is performed from the surface side where the high refractive index portion 11 is provided using the rotary blade B1-1 having a V-shaped tip, and the chamfered portion on the upper surface side 18 are formed (FIG. 17A: chamfered portion forming step).
Next, V-cut (bevel cut) is performed from the side where the guarantee function layer 19 is provided, using the rotary blade B1-2 having a V-shaped tip, to form a chamfered portion 18 on the lower side (FIG. 17). (B): Chamfered part formation process).
Next, a main cutting step (FIG. 17C) is performed in which the diffractive optical element wafer 100 is cut into pieces using the rotary blade B2 narrower than the V-cut width, and the chamfered portion 18 is formed on both sides The diffractive optical element 10 having the above is formed (FIG. 17D).
In addition, after performing V cut (bevel cut) from the side where the guarantee function layer 19 is provided, V cut is performed from the side where the high refractive index portion 11 is provided, and then the main cutting step is performed. May be

Alternatively, the cutting may be performed using only a V-shaped rotary blade without using the rotary blade B2.
FIG. 18 is a view showing an example in which the chamfered portion 18 is formed and singulated using only a rotary blade having a V-shaped tip.
In the example illustrated in FIG. 18, the rotary blades B1-3 and B1-4 having a narrower bevel angle (the angle of the cutting edge) than the rotary blades B1-1 and B1-2 illustrated in FIG. 17 are used.
First, V-cut (bevel cut) is performed from the surface side where the high refractive index portion 11 is provided using a rotary blade B1-3 having a V-shaped tip, to form a chamfer 18 on the upper surface (FIG. 18) (A): Chamfered part formation process).
Next, V-cut (bevel cut) is performed from the surface side on which the guarantee function layer 19 is provided using the rotary blade B1-4 having a V-shaped tip to form a chamfered portion to form the chamfered portion 18 on the lower surface side. The process and the main cutting process for cutting the diffractive optical element wafer 100 into pieces are simultaneously performed (FIG. 18B), and the diffractive optical element 10 having the chamfered portions 18 formed on both sides is manufactured (FIG. 18 (c).
In addition, after performing V cut (bevel cut) from the surface side in which the guarantee function layer 19 is provided, V cut may be performed from the surface side in which the high refractive index part 11 is provided, and it may cut | disconnect.

  According to the fourth embodiment described above, the chamfered portion 18 can be configured on both sides. Therefore, it is possible not only to suppress the generation of dust at the time of cutting and the generation of chipping of the base 12, but also to improve the bending strength in both directions. Although not shown, in the case of a diffractive optical element provided with diffraction gratings on both sides of a substrate, it is particularly desirable to provide chamfers 18 on both sides as in this embodiment.

(Confirmation of bending strength)
As described above, in the second to fourth embodiments, by providing the chamfered portion 18, it is described that the bending strength can be improved when the side on which the chamfered portion 18 is provided is bent as the outer side. . Since the experiment which demonstrated this was done, the experimental method and experimental result are shown below.
In this experiment, the bending strength was evaluated by a four-point bending test.
FIG. 19 is a view showing the test situation of the 4-point bending test.
As shown in FIG. 19, the test piece length Ls = 60 mm, the distance between supporting points L = 45 mm, and the distance between load points Li = 15 mm.

FIG. 20 is a cross-sectional view of three types of test pieces cut at the position of arrow A-A in FIG.
The test piece is the test piece without the chamfer shown in FIG. 20 (a), the test piece provided with the chamfer on the upper side shown in FIG. 20 (b), and the lower side shown in FIG. 20 (c) A test piece provided with a chamfered portion, a test piece provided with a chamfered portion on both sides cut after being chamfered on both sides shown in FIG. 20 (d), and V shown in FIG. 20 (e) There were prepared five types of test pieces provided with chamfers on both sides which were singulated using only rotating teeth of a shape. Further, since the high refractive index portion 11 and the like hardly affect the bending strength, only the glass base material 12 is used as the test piece. Each of these test pieces is produced by being cut by the same cutting process as that exemplified in the above embodiment.
The above-mentioned test pieces were subjected to a load test by an Instron-made electromechanical universal material tester 5900 series.

FIG. 21 summarizes the experimental conditions and the experimental results.
FIG. 22 is a graph showing the relationship between the angle of the chamfered portion and the maximum bending stress obtained from the experimental results.
The maximum load Fmax-ave was 15.87 N, and the maximum bending stress was 176.33 MPa when the maximum bending stress was determined from the maximum load Fmax-ave in the test piece without the chamfered portion.
The maximum load Fmax-ave is 13.12 N for the bevel angle θ = 30 °, 14.87 N for the θ = 45 °, and 14.82 N for the θ = 50 ° for the test piece with a chamfer on the top side. When θ = 60 °, it is 15.94 N. When the maximum bending stress is obtained from the maximum load Fmax-ave, 145.91 MPa when θ = 30 °, 165.32 MPa when θ = 45 °, θ = 50 ° In the case of 164.75 MPa, in the case of θ = 60 °, it is 177.18 MPa, and a clear difference with a test piece not equipped with a chamfer is not observed or a slight tendency to decrease.
On the other hand, in the case of a test piece with a chamfer on the lower surface side, the maximum load Fmax-ave is 16.13 N for θ = 30 °, 19.27 N for θ = 45 °, and θ = 50 °. In the case of 18.09 N, θ = 60 °, it is 17.30 N, and when the maximum bending stress is obtained from the maximum load Fmax-ave, it is 179.38 MPa in the case of θ = 30 °, 214.24 MPa in the case of θ = 45 ° 201.11MPa for = 50 °, 192.30MPa for θ = 60 °, and there is an improvement in bending strength for a test piece without a chamfer and a test piece with a chamfer on the top side It could be confirmed.
In addition, in the case of a test piece with chamfers on both sides, in the case of θ = 30 ° (two-step processing with only V-shaped rotary blades) 16.27 N, θ = 30 ° (main cutting after both-side chamfering processing) 19 When 43.N, θ = 45 °, 19.65 N, θ = 50 °, 19.87 N, θ = 60 °, 16.96 N, and the maximum bending stress is obtained from the maximum load Fmax-ave, θ = In the case of 30 ° (2 step machining with V-shaped rotary blade only) 181.18MPa, in the case of θ = 30 ° (main cutting after double-sided chamfering) 216.12MPa, in the case of θ = 45 ° 218.51MPa, θ = 50 Single-layer bending strength for test pieces without chamfers and test pieces with chamfers on the upper or lower surface side, which is 220.93 MPa for θ and 188.57 MPa for θ = 60 ° Improvement was confirmed.
This result is a result that the chipping which arises in glass at the time of cutting is controlled by preparation of a chamfer, and it is hard to produce stress concentration.
As described above, when the side on which the chamfered portion 18 is provided is bent outward, the bending strength can be improved by providing the chamfered portion 18.

(Observation confirmation of the cut end)
FIG. 23 is a view showing an enlarged photograph of an end face of the diffractive optical element actually cut. Fig.23 (a) shows the photograph which image | photographed the cut part cut | disconnected without providing a chamfer from the direction perpendicular | vertical to the diffraction grating surface of a diffractive optical element, FIG.23 (b) provided and cut the chamfer. The photograph which image | photographed the cutting part from the direction perpendicular | vertical to the diffraction grating surface of the diffractive optical element is shown. On the right side of FIG. 23, a reference cross-sectional view is also shown to facilitate understanding of the cutting position. Note that while the thickness of the substrate 12 made of glass is 300 μm (0.3 mm) while the thickness of the high refractive index portion 11 is 5 μm or less, this diffractive optical element is high in the photograph. The details of the refractive index layer 11 can not be confirmed.
In FIG. 23 (a), it can be confirmed that the end is rough since a large number of glass chips are generated at the end. On the other hand, in FIG. 23 (b), chipping of the glass is slightly suppressed, and roughening of the end can hardly be confirmed, resulting in a clean cutting line.
Further, in FIG. 23A, the presence of dust that is considered to be fragments of the high refractive index portion 11 can also be confirmed.

(Preferred form of chamfer 18)
FIG. 24 is a diagram for explaining the dimensions of the chamfered portion 18.
Here, with reference to FIG. 24, a preferable dimension as the chamfer 18 will be described.
The thickness t of the substrate 12 is preferably 0.2 mm or more and 1.0 mm or less. In the glass base 12 having this thickness t, it is preferable that the dimensions of each part of the chamfer 18 be in the following range in terms of suppression of dust generation and chipping of the base 12. .
It is desirable that the bevel angle θ be in the range of not less than 20 degrees and not more than 70 degrees.
The bevel width W is preferably in the range of t × 5% or more and t × 35% or less.
This should be as wide as possible without causing chipping and contamination due to the straight blade, and as narrow as not affecting the chip size and various functional layers on the chip (DOE pattern, ITO wiring, various marks, etc.) Is desirable.
The groove depth D is preferably in the range of t × 5% or more and t × 35% or less.
Further, it is preferable that the thickness of the high refractive index portion 11 and the thickness of the guarantee function layer 19 be 5% or less of the thickness t of the base 12.
In addition, although the range mentioned above is a preferable range, it is not limited to the value of this range.

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

(1) In each embodiment, the diffraction grating provided in the diffractive optical element 10 has been described by giving an example in which the multilevel shape of four levels is used. Not limited to this, the diffraction grating provided in the diffractive optical element 10 may have a multistep shape of eight levels or sixteen levels, a two-level uneven shape, a slunted shape in which two levels of uneven shapes are inclined, or The blazed shape may be such that the multi-step shape portion is a continuous slope. In addition, the slopes of the slanted shape and the blazed shape are not limited to flat surfaces, and may be curved shapes including free curved surfaces.

(2) In each embodiment, although the diffractive optical element is configured to include the base material, the diffractive optical element may be a simple form configured only by the high refractive index portion, or the low refractive index portion 14 is configured by resin You may provide and the coating layer which coats a diffraction layer may be provided.

(3) In each embodiment, the diffractive optical element has been described with an example designed to diffract light having a wavelength of 850 nm. For example, the present invention may be applied to a diffractive optical element that diffracts light of any wavelength, such as visible light, as well as infrared light.

(4) In each embodiment, the light irradiation device has been described by way of an example designed to irradiate light having a wavelength of 850 nm. Not limited to this, for example, the light source may emit light with a wavelength of 500 nm, and it is not limited to infrared light, and a light source that emits light of any wavelength such as visible light may be applied to the light irradiation device. May be

(5) In each embodiment, the light irradiation apparatus gave and demonstrated the example provided with one piece of the diffractive optical element 10. Not limited to this, a plurality of diffractive optical elements may be stacked. In that case, a plurality of diffractive optical element wafers may be stacked on a light source wafer, and then cutting may be performed. Alternatively, chamfers may be formed on the diffractive optical elements, and then individual pieces may be combined with light sources. May be When a plurality of such diffractive optical elements are stacked, the effect of the present invention works more effectively.

(6) In each embodiment, the light source part 20 showed and demonstrated an example of the specific structure provided with the light emitting element (light source) 21, the board | substrate 22, and the holder 24. FIG. Not only this but the structure of a light source part can apply a well-known various structure suitably. For example, in the embodiment, the light emitting element (light source) 21 is mounted on the substrate 22 and the space between the light emitting element 21 and the holder 24 is a space. It is good also as composition filled up, and it is good also as composition which serves as the function of holder 24 with filled resin (sealing material). Further, the function of the substrate 22 may be included in the light emitting element wafer to make the configuration simpler.
Further, in the case of forming a chamfered portion in the diffractive optical element and dividing the diffractive optical element in advance, the form of the holder 24 is not limited to the configuration of only the simple wall as exemplified in the embodiment. Alternatively, it may be configured as a stepped portion in which the portion for containing the diffractive optical element is lowered by one step. Further, the chamfered portion may be disposed toward the light source side. As for the position of the chamfered portion, an optimal arrangement can be selected as appropriate assuming a direction in which bending may occur due to stress.
Further, although the example in which the concavo-convex shape of the diffraction grating provided in the diffractive optical element is disposed on the emission side (the side far from the light source) has been described, the invention is not limited thereto. For example, the concavo-convex shape of the diffraction grating is incident It may be disposed toward the side (the side closer to the light source).
In addition, a plurality of diffractive optical elements may be stacked.
Further, not limited to the above-described configuration, the specific configuration or manufacturing method of the light source unit may be appropriately replaced with a known configuration.

  In addition, although embodiment and a deformation | transformation form can also be combined and used suitably, detailed description is abbreviate | omitted. Further, the present invention is not limited by the embodiments described above.

1, 1B light irradiation device 10 diffractive optical element 11 high refractive index portion 11a-1 level 1 step portion 11a-2 level 2 step portion 11a-3 level 3 step portion 11a-4 level 4 step portion 11b sidewall portion 12 base material 13 Adhesive layer 14 Low refractive index portion 14a Concave portion 14b Space 15 Diffractive layer 16 Mark 17 Unit cell 18 Chamfered portion 19 Guaranteed function layer 20 Light source portion 21 Light emitting element 22 Substrate 23 Wiring 24 Holder 24a Top portion 60 Adhesive material 100 Diffractive optical element wafer 200 Light source Wafer 300, 401, 402, 403 Original version

Claims (34)

Light source,
A diffractive optical element having a rectangular unit cell, which is disposed at a position where light from the light source is irradiated, and a plurality of diffraction gratings are formed to obtain a specific light distribution characteristic;
Equipped with
The light irradiator according to claim 1, wherein the diffractive optical element includes a plurality of unit cells periodically arranged, and a diffraction grating is formed up to an end of the diffractive optical element. In the light irradiation device according to claim 1,
At the boundary where the unit cells are adjacent, the diffraction grating pattern is continuous,
A light irradiation device characterized by In the light irradiation device according to claim 1 or 2,
The diffractive optical element is provided with a mark that can be distinguished from the diffraction grating.
A light irradiation device characterized by In the light irradiation device according to claim 3,
The mark is disposed so as to overlap the area where the diffraction grating is disposed.
A light irradiation device characterized by The light irradiation apparatus according to any one of claims 1 to 4.
The unit cell has a size capable of being arranged in a plurality within the irradiation range of the light irradiated from the light source,
A light irradiation device characterized by In the light irradiation device according to any one of claims 1 to 5,
The unit cell is formed with a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments when viewed from the normal direction of the surface on which the uneven shape is formed. is being done,
A light irradiation device characterized by In the light irradiation device according to any one of claims 1 to 6,
The diffractive optical element has a chamfered portion at least at the end on the side where the diffraction grating is formed,
A light irradiation device characterized by In the light irradiation device according to claim 7,
The diffractive optical element is
Equipped with a substrate made of glass,
The chamfered portion is formed to at least a position reaching the base,
A light irradiation device characterized by In the light irradiation device according to claim 7 or 8,
The chamfers are provided on both surfaces of the diffractive optical element,
A light irradiation device characterized by A light source polygon having a plurality of light sources arranged side by side,
A plurality of rectangular unit cells configured to obtain a specific light distribution characteristic by forming a plurality of diffraction gratings are arranged side by side, and a plurality of the unit cells are periodically arranged, and the unit is configured The cell is a diffractive optical element polyhedron which is continuously arranged regardless of the area to be cut and separated.
Bonding step of bonding
The light source polyhedron bonded in the bonding step and a cutting step of cutting the diffractive optical element polyhedron;
Method of manufacturing a light irradiation apparatus comprising: In the method of manufacturing a light irradiation device according to claim 10,
At the boundary where the unit cells are adjacent, the diffraction grating pattern is continuous,
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to claim 10 or 11,
The diffractive optical element polygon is provided with a mark that can be distinguished from a diffraction grating.
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to claim 12,
The mark is disposed so as to overlap the area where the diffraction grating is disposed.
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to claim 13,
The cutting step determines the cutting position using the mark.
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to any one of claims 10 to 14,
The unit cell has a size capable of being arranged in a plurality within the irradiation range of the light irradiated from the light source,
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to any one of claims 10 to 15,
The unit cell is formed with a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments when viewed from the normal direction of the surface on which the uneven shape is formed. is being done,
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to any one of claims 10 to 16,
The cutting step includes a chamfered portion forming step of forming a chamfered portion at least on the side where the diffraction grating is formed;
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to claim 17,
The diffractive optical element polyhedron is
Equipped with a substrate made of glass,
Forming the chamfered portion to a position at least reaching the base material in the chamfered portion forming step;
A method of manufacturing a light irradiation device characterized by In the manufacturing method of the light irradiation device according to claim 17 or 18,
In the chamfered portion forming step, processing is performed from both sides of the diffractive optical element polyhedron so as to form the chamfers on both sides of the joined light source polyhedron and the diffractive optical element polyhedron.
A method of manufacturing a light irradiation device characterized by In the method of manufacturing a light irradiation device according to any one of claims 17 to 19,
In the chamfered portion forming step, at least one of the light source polyhedron and the diffractive optical element polyhedron are connected without being separated.
After the chamfered portion forming step, the method further includes a main cutting step of cutting the light source polyhedron and the diffractive optical element polyhedron into pieces.
A method of manufacturing a light irradiation device characterized by A plurality of rectangular unit cells formed by forming a plurality of diffraction gratings to obtain a specific light distribution characteristic are arranged side by side, and a plurality of the unit cells are periodically arranged.
The unit cell is a diffractive optical element multifaceted body which is continuously arranged regardless of a region to be cut and separated. In the diffractive optical element polyhedron according to claim 21,
At the boundary where the unit cells are adjacent, the diffraction grating pattern is continuous,
A diffractive optical element multifaceted body characterized by In the diffractive optical element polyhedron according to claim 21 or 22,
It has marks that can be distinguished from diffraction gratings,
The mark is disposed so as to overlap the area where the diffraction grating is disposed.
A diffractive optical element multifaceted body characterized by In the diffractive optical element polyhedron according to claim 23,
The mark is disposed at each planned cutting straight line where cutting is scheduled,
A diffractive optical element multifaceted body characterized by In the diffractive optical element polyhedron according to claim 23 or 24,
The mark is arranged for each area to be cut and separated.
A diffractive optical element multifaceted body characterized by In the diffractive optical element polyhedron according to any one of claims 21 to 25,
The unit cell is formed with a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments when viewed from the normal direction of the surface on which the uneven shape is formed. is being done,
A diffractive optical element multifaceted body characterized by A diffraction in which a plurality of rectangular unit cells configured to obtain a specific light distribution characteristic by forming a plurality of diffraction gratings are arranged side by side, and a plurality of unit cells are periodically arranged. A method of manufacturing a diffractive optical element polyhedral body for manufacturing an optical element polyhedral body, comprising:
A forming die preparing step of preparing a forming die corresponding to divided regions obtained by dividing a region in which a diffraction grating is formed into a plurality of parts;
A forming step of forming a diffraction grating using the forming die;
A method of manufacturing a diffractive optical element multifaceted body comprising: 28. A method of manufacturing a diffractive optical element polyhedron according to claim 27, wherein
The forming step includes the step of sequentially forming different regions using the same forming die,
The manufacturing method of the diffractive optical element polyhedron body characterized by these. In the method of manufacturing a diffractive optical element polyhedron according to claim 27 or 28
The unit cell is formed with a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments when viewed from the normal direction of the surface on which the uneven shape is formed. is being done,
The manufacturing method of the diffractive optical element polyhedron body characterized by these.   A plurality of diffraction gratings are formed to have a rectangular unit cell configured to obtain a specific light distribution characteristic, the diffraction grating is formed up to the end, and at least the diffraction grating is formed. A diffractive optical element having a chamfered portion at the end on the side where the lens is located. In the diffractive optical element according to claim 30,
The unit cell is formed with a diffraction grating having a pattern including at least one of a curved line and a broken line connecting a plurality of line segments when viewed from the normal direction of the surface on which the uneven shape is formed. is being done,
A diffractive optical element characterized by 32. The diffractive optical element according to claim 30, wherein
Equipped with a substrate made of glass,
The chamfered portion is formed to at least a position reaching the base,
A diffractive optical element characterized by The diffractive optical element according to any one of claims 30 to 32,
The chamfers are provided on both surfaces of the diffractive optical element,
A diffractive optical element characterized by A method of manufacturing a diffractive optical element according to any one of claims 30 to 33, wherein
A plurality of rectangular unit cells formed by forming a plurality of diffraction gratings to obtain a specific light distribution characteristic are arranged side by side, and a plurality of the unit cells are periodically arranged. The unit cell comprises a cutting step of cutting the diffractive optical element multifaceted body continuously arranged irrespective of the area to be cut and separated into pieces.
The method of manufacturing a diffractive optical element, wherein the cutting step includes a chamfered portion forming step of forming a chamfered portion at least on an end portion on a side where the diffraction grating is formed.