WO2019181457A1

WO2019181457A1 - Light source system, optical diffraction element manufacturing method, distance measurement system, and optical diffraction element

Info

Publication number: WO2019181457A1
Application number: PCT/JP2019/008353
Authority: WO
Inventors: 勝治木村
Original assignee: ソニーセミコンダクタソリューションズ株式会社
Priority date: 2018-03-19
Filing date: 2019-03-04
Publication date: 2019-09-26

Abstract

This light source system comprises a light source for emitting light and an optical diffraction element including: a diffraction grating part that is formed on one surface of the optical diffraction element, has a prescribed pattern of openings upon which the light from the light source is incident, and generates diffracted light from the incident light, and a zero-order light correction part that is formed in at least a partial region of a region of another surface opposing the one surface, the region corresponding to the openings when viewed in the direction of the incidence of the light from the light source, and reduces the zero-order light generated by the diffraction grating part.

Description

Light source system, optical diffractive element manufacturing method, distance measuring system, and optical diffractive element

The present disclosure relates to a light source system, an optical diffraction element manufacturing method, a ranging system, and an optical diffraction element.

In recent years, solid-state imaging devices and biometric authentication devices that perform biometric authentication such as face authentication using a ranging function in order to prevent impersonation and fraud in electronic payment processing such as mobile terminal devices with cameras and banks, etc. It is becoming popular. In such an apparatus, as a technique for miniaturization, thinning, and high performance, infrared light that is collimated light is irradiated onto an optical diffraction element (DOE), and diffracted light is generated by the optical diffraction element. A method of performing ranging and biometric authentication based on the diffracted light is generally used. For example, a general method is to perform biometric authentication by irradiating a subject with diffracted light, capturing reflected light from the subject, converting the image data into image data, and performing distance measurement by analyzing the reflected light.

JP 2013-190394 A JP2015-115527A JP2015-132546A

In the above apparatus, when the diffracted light is generated by the optical diffractive element, 0th-order light and multi-order light are generated. However, since the light intensity differs between the 0th-order light and the multi-order light, the reflected light is The zero-order light component cannot be accurately analyzed when the image is taken, and the accuracy of ranging and biometric authentication can be reduced.

It is desirable to provide a light source system, a ranging system, and an optical diffractive element that can reduce the intensity of 0th-order light. It is also desirable to provide an optical diffraction element manufacturing method capable of manufacturing an optical diffraction element that reduces the intensity of zero-order light.

A light source system according to an embodiment of the present disclosure includes a light source that emits light, an opening having a predetermined pattern that is formed on one surface and receives light from the light source, and generates diffracted light based on the incident light. The generated diffraction grating portion and the other surface opposite to one surface are formed in at least a part of the region corresponding to the opening when viewed from the incident direction of light from the light source, and generated in the diffraction grating portion. And an optical diffraction element including a zero-order light correction unit that reduces the next light.

An optical diffraction element manufacturing method according to an embodiment of the present disclosure includes a step of forming a light shielding member in a predetermined pattern on one surface of a substrate, and a liquid on the other surface facing the one surface of the substrate. It includes a step of bringing the UV curable resin into contact, a step of irradiating the substrate with UV light from one surface side, and a step of cleaning the other surface of the substrate.

A distance measuring system according to an embodiment of the present disclosure includes a light source that emits light, an opening having a predetermined pattern that is formed on one surface and into which light from the light source is incident, and diffracted light based on the incident light Is formed in at least a part of the region corresponding to the opening when viewed from the incident direction of the light from the light source on the other surface opposite to the one surface. An optical diffractive element including a 0th order light correcting unit for reducing 0th order light, an image capturing unit that captures reflected light of the diffracted light emitted from the optical diffractive element and applied to the subject, and generates image data; A distance calculation unit that calculates a distance to the subject based on the data.

An optical diffractive element according to an embodiment of the present disclosure includes a substrate and a diffraction pattern that is formed on one surface of the substrate, has a predetermined pattern of light incident, and generates diffracted light based on the incident light. Reduced zero-order light generated in the diffraction grating section, formed in at least a part of the area corresponding to the aperture when viewed from the incident direction of light on the other surface of the substrate facing the grating portion and one surface A 0th-order light correction unit.

In the light source system, distance measuring system, or optical diffraction element according to an embodiment of the present disclosure, diffracted light is generated by the diffraction grating unit. The 0th-order light correction unit reduces the 0th-order light generated in the diffraction grating unit.
In the optical diffraction element manufacturing method according to an embodiment of the present disclosure, an optical diffraction element capable of reducing zero-order light is manufactured.

It is a block diagram which shows roughly the example of 1 structure of the light source system which concerns on a 1st comparative example, and a ranging system. It is explanatory drawing which shows roughly an example of the light intensity measured in the ranging system which concerns on a 1st comparative example. It is a block diagram which shows roughly the example of 1 structure of the light source system which concerns on a 2nd comparative example, and a ranging system. It is a lineblock diagram showing roughly the example of 1 composition of the light source system and distance measuring system concerning a 1st embodiment of this indication. It is sectional drawing and the top view which show roughly the example of 1 structure of the optical diffraction element which concerns on 1st Embodiment. It is process drawing which shows an example of the manufacturing method of the optical diffraction element which concerns on 1st Embodiment. It is sectional drawing and a top view which show roughly the example of 1 structure of the optical diffraction element which concerns on the 1st modification of 1st Embodiment. It is sectional drawing and the top view which show roughly the example of 1 structure of the optical diffraction element which concerns on the 2nd modification of 1st Embodiment. It is a block diagram which shows roughly the example of 1 structure of the light source system and distance measuring system which concern on 2nd Embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order.
1. First Embodiment 1.0 Comparative Example (FIGS. 1 to 3)
1.1 Configuration and operation of the light source system and ranging system according to the first embodiment (FIGS. 4 to 5)
1.2 Optical diffraction element manufacturing method according to the first embodiment (FIG. 6)
1.3 Modifications of the optical diffraction element according to the first embodiment (FIGS. 7 to 8)
1.4 Effects Second embodiment (FIG. 9)
3. Other embodiments

<1. First Embodiment>
The technology of the present disclosure irradiates CSP (Chip Size Package) solid-state imaging devices such as CCD (Charged Coupled Devices) sensors, CMOS (Complementary Metal Oxide Semiconductor) image sensors, and diffracted light for measuring the distance between subjects. The present invention relates to a ranging system including a light source system. A light source system and a ranging system of the present disclosure include, for example, a digital camera such as a digital video camera and a digital still camera, an image input camera such as a surveillance camera and an in-vehicle camera, a scanner device, a facsimile device, a television phone device, and a camera. The present invention can be applied to electronic information devices such as attached mobile terminal devices. In addition, the light source system and the distance measuring system of the present disclosure can be applied to a biometric authentication device and an inspection device.

[1.0 Comparative Example]
In Patent Document 2 (Japanese Patent Laid-Open No. 2015-115527) and Patent Document 3 (Japanese Patent Laid-Open No. 2015-132546), examples for performing general distance measurement are disclosed. A technique for solving the problem of light intensity due to the secondary light component is not described. The technique described in Patent Document 1 (Japanese Patent Laid-Open No. 2013-190394) has two solid-state imaging devices and can avoid the light intensity due to the 0th-order light component, but has two solid-state imaging devices. There is a problem that it becomes expensive. Further, in the technique described in Patent Document 1, in order to irradiate light of a random pattern, it takes time for analysis to measure the distance from image data after the reflected light is imaged by two solid-state imaging devices. There is a problem that the immediacy required for authentication is lost.

In Patent Document 1, the pattern illumination device is arranged so that the pattern light irradiated to the measurement object does not include the zero-order light generated by the diffractive optical element, thereby avoiding the degradation of ranging performance due to the zero-order light. The technology to do is described. However, the technique described in Patent Document 1 requires two cameras (stereo cameras) that capture a random pattern for distance measurement, and is expensive. Further, as described in FIG. 8 of Patent Document 1, even in the case of a random pattern, zero-order light is generated, and in order to avoid this, the position of the zero-order light is set to the distance between the cameras of the stereo camera. We take measures by changing.

The technique described in Patent Document 2 is an example of a solid-state imaging device that realizes acquisition of color signals and distance measurement with a single camera, but means for avoiding degradation in distance measurement performance due to zero-order light is described. Absent. For this reason, it is inevitable that the distance measurement performance of the diffractive optical element is reduced by the 0th-order light.

The technique described in Patent Document 3 attempts to increase the accuracy of distance measurement by changing the light emitted from the diffractive optical element to light in two different directions depending on the astigmatism lens. The need for an astigmatism lens is expensive. Also, Patent Document 3 does not describe countermeasures for zero-order light.

FIG. 1 schematically shows a configuration example of a light source system and a distance measuring system according to a first comparative example. FIG. 2 schematically shows an example of the light intensity measured in the distance measuring system according to the first comparative example.

The distance measuring system according to the first comparative example includes a light source system including a light source 1 and an optical diffraction element 200 and an imaging camera 3.

The light source 1 irradiates the optical diffraction element 200 with collimated light including infrared light, for example. The optical diffraction element 200 is formed with a predetermined pattern for generating the diffracted light Ld. The optical diffraction element 200 generates diffracted light Ld from the light emitted from the light source 1. The diffracted light Ld emitted from the optical diffraction element 2 is applied to the subject 10. The reflected light applied to the subject 10 is imaged by the imaging camera 3. The imaging camera 3 has a solid-state imaging device, for example. The imaging camera 3 stores and analyzes imaging data of the diffracted light Ld. In general, the diffracted light Ld is analyzed in the imaging camera 3 to measure the distance to the subject 10, the unevenness of the subject 10, and the like.

However, not only the diffracted light Ld but also light (0th-order light L0) that is not diffracted by the optical diffractive element 200 is emitted from the optical diffractive element 200 and irradiated onto the subject 10. For this reason, the captured image obtained by the imaging camera 3 includes diffracted light Ld and zero-order light L0 as schematically shown in FIG. In general, the light intensity of the 0th-order light L0 is higher than the light intensity of the diffracted light Ld. For this reason, for example, in the imaging camera 3, when exposure adjustment is performed so that diffracted light Ld other than the 0th-order light L0 is optimally imaged data by an electronic shutter, a mechanical shutter, or a diaphragm, as schematically illustrated in FIG. As shown in FIG. 4, there is a problem that the light intensity of the 0th-order light L0 is strong and becomes saturated.

As a distance analysis method in the distance measuring system according to the first comparative example of FIG. 1, as shown in FIG. 2, the center of gravity of the reflected light circle of the diffracted light Ld irradiated to the subject 10 is obtained. There is a method for calculating the distance to the subject 10. At this time, a method is adopted in which the reflected light component of the 0th-order light L0 is not used when calculating the distance. However, it is clear that the resolution of distance measurement deteriorates unless the 0th-order light L0 is used. Further, in the imaging camera 3, when the exposure is adjusted by the electronic shutter, the mechanical shutter, or the aperture so that the 0th-order light L0 is optimally imaged data, the intensity of the diffracted light Ld other than the 0th-order light L0 is high. Obviously, it becomes smaller and it becomes difficult to calculate the distance.

FIG. 3 schematically shows an example of a light source system and a ranging system according to the second comparative example.

The light source system according to the second comparative example includes a 0th-order light correction element 5 as a countermeasure against the 0th-order light with respect to the ranging system according to the second comparative example of FIG. The zero-order light correction element 5 is provided separately from the optical diffraction element 200. The 0th-order light correction element 5 is a pattern that reduces the 0th-order light L0 of the optical diffractive element 200 in order to reduce the 0th-order light L0 from the optical diffractive element 200 (a predetermined pattern formed on the optical diffractive element 200). Has the opposite pattern). However, in this method, since the optical diffraction element 200 and the zero-order light correction element 5 are provided as separate bodies, it is difficult to align the patterns formed with each other, and there is a problem in that the yield decreases. .

[1.1 Configuration and Operation of Light Source System and Ranging System According to First Embodiment]
FIG. 4 schematically illustrates a configuration example of the light source system and the distance measuring system according to the first embodiment of the present disclosure. FIG. 5 schematically shows a cross-sectional configuration example and a planar configuration example of the optical diffraction element 2 according to the first embodiment. In the following description, substantially the same components as those of the light source system and the distance measuring system according to the comparative example are denoted by the same reference numerals, and description thereof is omitted as appropriate.

As shown in FIG. 4, the distance measuring system according to the first embodiment includes a light source system including a light source 1 and an optical diffraction element 2, an imaging camera 3, a distance calculation unit 31, and a shape recognition unit 32. And a biometric authentication unit 33.

The imaging camera 3 captures the reflected light of the diffracted light Ld emitted from the optical diffraction element 2 and applied to the subject 10 to generate image data. The distance calculation unit 31 calculates the distance to the subject 10 based on the image data. Based on the distance data calculated by the distance calculation unit 31, the shape recognition unit 32 discriminates irregularities such as the face of the subject 10 and recognizes the shape of the subject 10. The biometric authentication unit 33 performs biometric authentication such as face authentication based on the recognition result by the shape recognition unit 32.

The optical diffraction element 2 includes a glass substrate 20, a diffraction grating unit 6, and a zero-order light correction unit 24 as shown in FIG. The glass substrate 20 is disposed between the diffraction grating unit 6 and the zero-order light correction unit 24.

The diffraction grating portion 6 is formed on one surface 21 of the glass substrate 20. The diffraction grating unit 6 includes an opening having a predetermined pattern through which light from the light source 1 enters and a light shielding unit 25 as a light shielding member that shields light, and generates diffracted light Ld based on the incident light. In the example of FIG. 5, the predetermined pattern is a circular hole shape, and the diffraction grating portion 6 has a circular hole 23 as an opening.

The zero-order light correction unit 24 is formed on the other surface 22 of the glass substrate 20 facing the one surface 21. The zero-order light correction unit 24 is formed of, for example, a UV curable resin 41 as shown in FIG. The 0th-order light correction unit 24 is formed with an ND (Neutral Density) pattern or a black pattern in order to reduce the 0th-order light L0 generated in the diffraction grating unit 6. Thereby, the optical diffraction element 2 has a function of adjusting the 0th-order light L0 as compared with the optical diffraction element 200 (FIG. 1) in the comparative example. The zero-order light correction unit 24 is formed in at least a part of the region corresponding to the opening (circular hole 23) of the diffraction grating unit 6 when viewed from the incident direction of the light from the light source 1. The size of the 0th-order light correction unit 24 is preferably substantially the same as or larger than the opening of the diffraction grating unit 6 in order to reduce the 0th-order light L0. In addition, the shape of the zero-order light correction unit 24 is preferably substantially the same as the opening of the diffraction grating unit 6 in order to reduce the zero-order light L0. However, even if the size of the 0th-order light correction unit 24 is smaller than the opening of the diffraction grating unit 6, the effect of reducing the 0th-order light L0 can be obtained. For this reason, the size of the zero-order light correction unit 24 may be smaller than the opening of the diffraction grating unit 6. Even if the shape of the zero-order light correction unit 24 is slightly different from the opening of the diffraction grating unit 6, the effect of reducing the zero-order light L0 can be obtained. For this reason, the shape of the zero-order light correction unit 24 may be slightly different from the opening of the diffraction grating unit 6.

In FIG. 5, TOPVIEW indicates a surface on the light source 1 side, and BottomView indicates a surface on the subject 10 side. For example, collimated light including infrared light from the light source 1 is incident on the optical diffraction element 2 from TOPV View. The optical diffraction element 2 emits the diffracted light Ld generated by the diffraction grating unit 6 to the subject 10 from the Bottom View side. When the optical diffraction element 2 has the configuration shown in FIG. 5, the diffraction grating portion 6 has a circular hole 23 as an opening, and thus the subject 10 is irradiated with circular diffracted light Ld. On the other hand, the 0th-order light L0 generated in the diffraction grating unit 6 is adjusted so that the light intensity is reduced by the 0th-order light correction unit 24 formed of an ND pattern or a black pattern.

[1.2 Optical diffractive element manufacturing method according to first embodiment]
FIG. 6 shows an example of a method for manufacturing the optical diffraction element 2.

First, as shown in FIG. 6A, for example, a black light shielding member is applied to one surface 21 of the glass substrate 20 in a predetermined pattern. As a result, the light shielding part 25 and the opening (circular hole 23) to be the diffraction grating part 6 are formed on one surface 21 of the glass substrate 20.

Next, the zero-order light correction unit 24 is formed on the other surface 22 of the glass substrate 20, and the pattern of the zero-order light correction unit 24 is accurately formed at a position facing the opening formed on the one surface 21. It is preferable to do. Therefore, next, as shown in FIG. 6B, a liquid UV curable resin 41 is brought into contact with the other surface 22 of the glass substrate 20 facing the one surface 21. The liquid UV curable resin 41 is colored so as to be ND or black.

Next, as shown in FIG. 6C, the glass substrate 20 is irradiated with UV light from the one surface 21 side to cure the liquid UV curable resin 41 brought into contact with the other surface 22. Let The UV curable resin 41 is cured by the UV light (corresponding to the 0th-order light L0 generated in the diffraction grating portion 6) transmitted through the opening formed on the one surface 21. As a result, the ND pattern or black pattern zero-order light correction unit 24 is formed in a region corresponding to the opening formed in the one surface 21 on the other surface 22. At this time, the UV curable resin 41 may remain semi-fixed on the other surface 22 in a region other than the region corresponding to the opening formed on the one surface 21.

Therefore, finally, as shown in FIGS. 6D and 6E, the other surface 22 of the glass substrate 20 is separated from the liquid UV curable resin 41, and the other surface 22 is cleaned. Thereby, the UV curable resin 41 that remains after being semi-fixed is removed.

(Modification of optical diffraction element manufacturing method)
In the manufacturing method described above, a hybrid curable resin with a thermosetting resin may be used instead of the UV curable resin 41 when the zero-order light correction unit 24 is formed.

Further, in the manufacturing method described above, the zero-order light correction unit 24 may be formed by temporarily fixing with the UV curable resin 41, cleaning, and then fixing with a thermosetting resin. Alternatively, the zero-order light correction unit 24 may be formed by temporarily fixing with the UV curable resin 41, then performing permanent fixing with a thermosetting resin, and then performing cleaning.

[1.3 Modification of Optical Diffraction Element According to First Embodiment]
FIG. 7 schematically shows a cross-sectional configuration example and a planar configuration example of an optical diffraction element 2A according to a first modification of the first embodiment. FIG. 8 schematically shows a cross-sectional configuration example and a planar configuration example of an optical diffraction element 2B according to a second modification of the first embodiment.

FIG. 5 shows a configuration example in which the diffraction grating portion 6 has a circular hole 23 as an opening of a predetermined pattern. However, the predetermined pattern is not limited to a circular hole pattern, for example, a linear pattern or a random pattern. It may be a pattern.

For example, like the optical diffraction element 2A according to the first modification shown in FIG. 7, the diffraction grating portion 6A formed on one surface 21 has a line hole 23A as an opening of a predetermined pattern. Also good. In this case, a 0th-order light correction unit 24A having a linear pattern corresponding to the line hole 23A is formed on the other surface 22.

Further, for example, as in the optical diffraction element 2B according to the second modification shown in FIG. 8, the diffraction grating portion 6A formed on one surface 21 has a random hole 23B as an opening of a predetermined pattern. May be. In this case, a 0th-order light correction unit 24B having a random pattern corresponding to the random hole 23B is formed on the other surface 22.

[1.4 Effect]
As described above, according to the light source system and the distance measuring system according to the first embodiment, since the optical diffraction element having the 0th-order light correction unit is provided, the 0th-order light generated in the diffraction grating unit. It becomes possible to reduce the intensity of L0. Thereby, it is possible to measure the distance with high accuracy by effectively adjusting the intensity of the 0th-order light L0. Thereby, for example, highly accurate biometric authentication can be performed.

It should be noted that the effects described in this specification are merely examples and are not limited, and other effects may be obtained. The same applies to the effects of the other embodiments thereafter.

<2. Second Embodiment>
Next, a light source system and a distance measuring system according to the second embodiment of the present disclosure will be described. In the following description, the same reference numerals are given to substantially the same components as those of the light source system and the ranging system according to the first embodiment, and the description thereof will be omitted as appropriate.

FIG. 9 schematically shows a configuration example of the light source system and the distance measuring system according to the second embodiment.

The light source system and ranging system according to the second embodiment are configured to further include a correction lens 4 with respect to the light source system and ranging system according to the first embodiment. The correction lens 4 is disposed between the light source 1 and the optical diffraction element 2 and corrects the light from the light source 1 to be parallel light.

Generally, infrared light is used for ranging and biometric authentication. The optical diffraction element 2 is preferably irradiated with infrared light that is collimated light. It is generally known that a certain distance is required between the light source 1 and the optical diffraction element 2 in order to emit highly accurate collimated light from the light source 1. By disposing the correction lens 4 between the light source 1 and the optical diffraction element 2, the distance between the light source 1 and the optical diffraction element 2 can be reduced.

Other configurations, operations, and effects may be substantially the same as those of the light source system and the ranging system according to the first embodiment.

<3. Other Embodiments>
The technology according to the present disclosure is not limited to the description of each of the above embodiments, and various modifications can be made.

In each of the above embodiments, the case where the distance data calculated by the distance calculation unit 31 is used for biometric authentication has been described as an example, but the distance data may be used for purposes other than biometric authentication.

For example, this technique can also take the following structures.
According to the present technology having the following configuration, the intensity of the zero-order light can be reduced. In addition, it is possible to manufacture an optical diffraction element that reduces the intensity of zero-order light.

(1)
A light source that emits light;
A diffraction grating portion that is formed on one surface and has a predetermined pattern opening through which light from the light source is incident, and that generates diffracted light based on the incident light, and on the other surface facing the one surface And an optical system including a zeroth-order light correction unit that is formed in at least a part of a region corresponding to the opening when viewed from the incident direction of light from the light source and reduces zeroth-order light generated in the diffraction grating unit. A light source system comprising a diffraction element.
(2)
A correction lens that is disposed between the light source and the optical diffraction element and corrects the light from the light source to be parallel light;
The light source system according to (1), further comprising:
(3)
The light source system according to (1) or (2), wherein the zero-order light correction unit is formed of a UV curable resin.
(4)
The light source system according to any one of (1) to (3), wherein the predetermined pattern is any one of a circular hole shape, a linear shape, and a random shape.
(5)
The light source system according to (3), wherein the UV curable resin is cured by being irradiated with UV light that has passed through the diffraction grating portion.
(6)
The light source system according to any one of (1) to (5), wherein the optical diffraction element includes a substrate disposed between the diffraction grating portion and the zero-order light correction portion.
(7)
Forming a light shielding member in a predetermined pattern on one surface of the substrate;
A step of bringing a liquid UV curable resin into contact with the other surface of the substrate facing the one surface;
Irradiating the substrate with UV light from the one surface side;
Cleaning the other surface of the substrate. An optical diffraction element manufacturing method.
(8)
The step of irradiating the UV light includes
The method for producing an optical diffraction element according to (7), further comprising a step of curing the liquid UV curable resin in contact with the other surface.
(9)
A light source that emits light;
A diffraction grating portion that is formed on one surface and has a predetermined pattern opening through which light from the light source is incident, and that generates diffracted light based on the incident light, and on the other surface facing the one surface And an optical system including a zeroth-order light correction unit that is formed in at least a part of a region corresponding to the opening when viewed from the incident direction of light from the light source and reduces zeroth-order light generated in the diffraction grating unit. A diffraction element;
An imaging unit that captures reflected light of the diffracted light emitted from the optical diffraction element and applied to a subject to generate image data;
A distance measuring system comprising: a distance calculating unit that calculates a distance to the subject based on the image data.
(10)
A substrate,
A diffraction grating portion that is formed on one surface of the substrate and has a predetermined pattern of openings through which light enters, and that generates diffracted light based on the incident light;
Reduced zero-order light generated in the diffraction grating portion formed in at least a part of the region corresponding to the opening when viewed from the light incident direction on the other surface of the substrate facing the one surface. An optical diffraction element comprising: a zero-order light correction unit.

This application is filed with Japanese Patent Application No. 2018-050773 filed on March 19, 2018 at the Japan Patent Office and Japanese Patent Application No. 2018-203709 filed on October 30, 2018. The priority is claimed as a basis, and the entire contents of this application are incorporated herein by reference.

Those skilled in the art will envision various modifications, combinations, subcombinations, and changes, depending on design requirements and other factors, which are within the scope of the appended claims and their equivalents. It is understood that

Claims

A light source that emits light;
A diffraction grating portion that is formed on one surface and has a predetermined pattern of openings through which light from the light source is incident, and that generates diffracted light based on the incident light;
The zero-order light generated in the diffraction grating portion is formed on at least a part of the region corresponding to the opening when viewed from the incident direction of the light from the light source on the other surface facing the one surface. A light source system comprising: an optical diffractive element including a 0th-order light correction unit to reduce.
A correction lens that is disposed between the light source and the optical diffraction element and corrects the light from the light source to be parallel light;
The light source system according to claim 1, further comprising:
The light source system according to claim 1, wherein the zero-order light correction unit is formed of a UV curable resin.
The light source system according to claim 1, wherein the predetermined pattern is any one of a circular hole shape, a linear shape, and a random shape.
The light source system according to claim 3, wherein the UV curable resin is cured by being irradiated with UV light that has passed through the diffraction grating portion.
The light source system according to claim 1, wherein the optical diffraction element includes a substrate disposed between the diffraction grating part and the zero-order light correction part.
Forming a light shielding member in a predetermined pattern on one surface of the substrate;
A step of bringing a liquid UV curable resin into contact with the other surface of the substrate facing the one surface;
Irradiating the substrate with UV light from the one surface side;
Cleaning the other surface of the substrate. An optical diffraction element manufacturing method.
The step of irradiating the UV light includes
The method of manufacturing an optical diffraction element according to claim 7, further comprising: curing the liquid UV curable resin in contact with the other surface.
A light source that emits light;
A diffraction grating portion that is formed on one surface and has a predetermined pattern opening through which light from the light source is incident, and that generates diffracted light based on the incident light, and on the other surface facing the one surface And an optical system including a zeroth-order light correction unit that is formed in at least a part of a region corresponding to the opening when viewed from the incident direction of light from the light source and reduces zeroth-order light generated in the diffraction grating unit. A diffraction element;
An imaging unit that captures reflected light of the diffracted light emitted from the optical diffraction element and applied to a subject to generate image data;
A distance measuring system comprising: a distance calculating unit that calculates a distance to the subject based on the image data.
A substrate,
A diffraction grating portion that is formed on one surface of the substrate and has a predetermined pattern of openings through which light enters, and that generates diffracted light based on the incident light;
Reduced zero-order light generated in the diffraction grating portion formed in at least a part of the region corresponding to the opening when viewed from the light incident direction on the other surface of the substrate facing the one surface. An optical diffraction element comprising: a zero-order light correction unit.