Optical module and distance measuring device

Abstract

The present application improves resolution while suppressing the number of light emitting elements arranged in an optical module. The optical module includes an optical element that makes a light beam emitted from a light emitting element a substantially collimated light beam or a light beam having a prescribed angular width, and a diffractive element that diffracts the light beam and separates the light beam into a plurality of light beams. The diffractive element generates diffracted light in n directions, and an angle θx formed by one of the directions of diffraction and an edge of the direction of arrangement of the light emitting element is tan ‑1 (b / 3a). A diffraction angle of the diffracted light is and an angle difference between two light beams caused by a distance between the light emitting elements of a and b is. n is a natural number, and m is a natural number that does not include an integral multiple of 2n+1.

Description

Technical Field

[0001] This technology relates to optical modules. Specifically, the present invention relates to an optical module that illuminates an object with a light beam and a distance measuring device using the optical module. Background Technology

[0002] An optical module that illuminates an object with a light beam is used to measure distances by means of time-of-flight (ToF) and object shape recognition. When such an optical module emits light in a spot shape, its resolution depends on the number of spots. Conversely, multipath correction techniques are known for correcting the effects of reflected light from objects outside the object itself. For example, a camera system has been proposed that performs multipath correction by switching between uniform illumination and spot illumination (see, for example, Patent Document 1).

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: U.S. Patent Application Publication No. 2013 / 0148102 Summary of the Invention

[0006] The problem to be solved by the present invention

[0007] As described above, when the number of light-emitting elements is increased to improve resolution, the contribution rate of the laser oscillation threshold current increases, and the electro-optical conversion efficiency decreases. Furthermore, there are limitations to arranging light-emitting elements with narrow spacing, and the area of ​​the light-emitting unit increases. Additionally, as the number of light spots increases, it becomes difficult to perform the aforementioned multipath correction.

[0008] Given this situation, this technology has been implemented, and its purpose is to improve resolution while reducing the number of light-emitting elements arranged in the optical module.

[0009] Problem Solving Methods

[0010] This technology was developed to address the aforementioned problems, and its first aspect is an optical module and a distance measuring device, comprising: a light-emitting unit including light-emitting elements arranged in a two-dimensional manner; and a diffraction element that diffracts a light beam emitted from each of the light-emitting elements and splits the light beam into multiple beams, wherein the light-emitting unit has a plurality of array structures constructed as follows: the light-emitting elements are arranged at the vertices of a quadrilateral and at the points where the diagonals of the quadrilateral intersect, the mutually facing sides of the quadrilateral are parallel to each other, wherein the distance between the light-emitting elements on the sides in a first direction is set as a, and the distance between the light-emitting elements on the sides in a second direction orthogonal to the sides in the first direction is set as b, the diffraction element generates diffracted light in n directions (n ​​is a natural number), wherein an angle θx formed between a diffraction direction and the sides in the first direction satisfies

[0011] θx=tan -1 (b / 3a), and

[0012] When the angular differences between the two beams generated by the distances a and b between the light sources are set to φa and φb respectively, and m is set to a natural number that is not an integer multiple of 2n+1, the diffraction angle φx of the diffracted light satisfies

[0013] φx=m·sqrt((3φa)^2+φb^2) / (2(2n+1)). This results in the diffraction element producing diffracted light in the n direction.

[0014] Furthermore, the first aspect may further include an optical element that converts the light beam emitted from the light-emitting element into a substantially parallel light beam or a light beam having a predetermined angular width. Even if the light beam emitted from the light-emitting element is not a substantially parallel light beam or a light beam having a predetermined angular width, this still provides the effect of providing a suitable light beam to the diffraction element.

[0015] Furthermore, the first aspect may further include a light detection unit that detects reflected light from the object relative to the beam. This results in the detection of reflected light from the object relative to the emitted beam.

[0016] Furthermore, in the first aspect described above, the light-emitting unit has a switching unit that switches the light-emitting elements that should emit light at every set of at least two. This results in the effect of switching the illumination pattern.

[0017] Furthermore, in the first aspect, each light-emitting element may include at least two active layers in the longitudinal direction. This results in an increase in the intensity of light emitted from each light-emitting element. Attached Figure Description

[0018] Figure 1This is a block diagram illustrating an example of the overall configuration of the ranging device 10 in an embodiment of the present technology.

[0019] Figure 2 This is a cross-sectional view showing an example of the configuration of the lighting unit 100 in an embodiment of the present technology.

[0020] Figure 3 This is a diagram illustrating an example of light emitted from the light-emitting unit 110 of an embodiment of the present technology.

[0021] Figure 4 This is a cross-sectional view showing an example of the configuration of the light-emitting unit 110 in an embodiment of the present technology.

[0022] Figure 5 This is a cross-sectional view showing a first construction example of the light-emitting element 111 in an embodiment of the present technology.

[0023] Figure 6 This is a cross-sectional view showing a second construction example of the light-emitting element 111 in an embodiment of the present technology.

[0024] Figure 7 This is a diagram illustrating an example of the illumination pattern of the diffraction element 114 in an embodiment of the present technology.

[0025] Figure 8 This is a diagram illustrating a construction example of the diffraction element 134 in the first embodiment of the present technology.

[0026] Figure 9 This is a diagram illustrating an example of the arrangement of light-emitting elements 111 in the light-emitting unit 110 of an embodiment of the present technology.

[0027] Figure 10 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 according to a first embodiment of the present technology.

[0028] Figure 11 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 in a first embodiment of the present technology.

[0029] Figure 12 This is a diagram illustrating a specific example of the light illumination spot pattern (without the diffraction element 134) in the first embodiment of the present technology.

[0030] Figure 13 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=1) in the first embodiment of the present technology.

[0031] Figure 14 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=2) in the first embodiment of the present technology.

[0032] Figure 15 This is a diagram illustrating a construction example of the diffraction element 134 in the second embodiment of the present technology.

[0033] Figure 16 This is a diagram illustrating an example of diffracted light through a light-emitting element 111 in a second embodiment of the present technology.

[0034] Figure 17 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 in a second embodiment of the present technology.

[0035] Figure 18 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=1) in the second embodiment of the present technology.

[0036] Figure 19 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=2) in the second embodiment of the present technology.

[0037] Figure 20 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=3) in the second embodiment of the present technology.

[0038] Figure 21 This is a diagram illustrating a specific example of a light-irradiated spot pattern (m=4) in the second embodiment of the present technology.

[0039] Figure 22 This is a diagram illustrating an example of diffracted light through a light-emitting element 111 in a modified embodiment of the second embodiment of the present technology.

[0040] Figure 23 This is a diagram illustrating an example of diffracted light through a plurality of light-emitting elements 111 in a modified example of the second embodiment of the present technology.

[0041] Figure 24 This is a diagram illustrating a specific example of a light irradiation spot pattern (m=2) in a modified example of the second embodiment of the present technology.

[0042] Figure 25 This is a diagram illustrating a specific example of a light-irradiated spot pattern (reversed 180 degrees) in a variation of the second embodiment of the present technology.

[0043] Figure 26 This is a diagram illustrating an example of diffracted light through a light-emitting element 111 in a third embodiment of the present technology.

[0044] Figure 27 This is a diagram illustrating an example of diffracted light through a plurality of light-emitting elements 111 in a third embodiment of the present technology.

[0045] Figure 28 This is a diagram illustrating a specific example of a light-irradiated spot pattern (m=1) in the third embodiment of this technology.

[0046] Figure 29 This is a diagram illustrating a specific example of a light-irradiated spot pattern (m=2) in the third embodiment of the present technology.

[0047] Figure 30 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=3) in the third embodiment of this technology.

[0048] Figure 31 This is a diagram illustrating a specific example of a light-irradiated spot pattern (m=4) in the third embodiment of the present technology.

[0049] Figure 32 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=5) according to the third embodiment of the present technology.

[0050] Figure 33 This is a diagram illustrating a specific example of a light-illuminating spot pattern (m=6) according to the third embodiment of the present technology.

[0051] Figure 34 This diagram illustrates an example of diffracted light through a light-emitting element 111 in the fourth embodiment of the present technology.

[0052] Figure 35 This diagram illustrates an example of diffracted light from a plurality of light-emitting elements 111 in the fourth embodiment of the present technology.

[0053] Figure 36 This diagram illustrates a specific example of a light-illuminating spot pattern (m=3) in the fourth embodiment of the present technology.

[0054] Figure 37 This diagram illustrates a specific example of a light-illuminating spot pattern (m=6) in the fourth embodiment of the present technology.

[0055] Figure 38 This is a diagram illustrating an example of the diffracted light of the light-emitting element 111 in a first variation of an embodiment of the present technology.

[0056] Figure 39 This is a diagram illustrating a specific example of a light-illuminating spot pattern in a first variation of an embodiment of the present technology.

[0057] Figure 40 This is a diagram illustrating an example of diffracted light through the light-emitting element 111 in a second variation of an embodiment of the present technology.

[0058] Figure 41 This is a diagram illustrating a specific example of a light-illuminating spot pattern in a second variation of an embodiment of the present technology.

[0059] Figure 42 This is a diagram illustrating a configuration example of the light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0060] Figure 43 This diagram illustrates a first example of a laser driver 118 that drives the light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0061] Figure 44 This is a diagram illustrating a second example of a laser driver 118 for a light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0062] Figure 45 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 on the X side in a first application example of an embodiment of the present technology.

[0063] Figure 46 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 on the X side in a first application example of an embodiment of the present technology.

[0064] Figure 47 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 on the Y side in a first application example of an embodiment of the present technology.

[0065] Figure 48 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 on the Y side in a first application example of an embodiment of the present technology.

[0066] Figure 49 This is a diagram illustrating a specific example of a light-illuminating spot pattern (light is emitted only on the X side) in a first application example of an implementation of the present technology.

[0067] Figure 50 This diagram illustrates a specific example of a light-illuminating spot pattern (light emitted only on the Y side) in a first application example of an embodiment of this technology.

[0068] Figure 51 This is a diagram illustrating a specific example of a light-illuminating spot pattern (emitting light on the X and Y sides) in a first application example of an embodiment of the present technology.

[0069] Figure 52 This is a diagram illustrating an example of the timing of the operation of the light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0070] Figure 53 This is a diagram illustrating a first example of a grouping of light-emitting elements 111 in a first application example of an embodiment of the present technology.

[0071] Figure 54 This is a diagram illustrating a second example of the grouping of light-emitting elements 111 in a first application example of an embodiment of the present technology.

[0072] Figure 55 This is a diagram illustrating a third example of the grouping of light-emitting elements 111 in a first application example of an embodiment of the present technology.

[0073] Figure 56 This is a diagram illustrating a fourth example of the grouping of light-emitting elements 111 in a first application example of an embodiment of the present technology.

[0074] Figure 57 This is a diagram illustrating an example of the configuration of the irradiation unit 100 in a second application example of an embodiment of the present technology.

[0075] Figure 58 This diagram illustrates an example of the behavior of a light beam in a second application example of an embodiment of the present technology.

[0076] Figure 59 This is a diagram illustrating a first configuration example of the light-emitting unit 110 in a second application example of an embodiment of the present technology.

[0077] Figure 60 This is a diagram illustrating a second configuration example of the light-emitting unit 110 in a second application example of an embodiment of the present technology.

[0078] Figure 61 This is a schematic diagram illustrating an example of an illumination pattern in a second application example of an embodiment of the present technology. Detailed Implementation

[0079] The modes for implementing this technology (hereinafter referred to as implementation methods) will be described below. The descriptions will be given in the following order.

[0080] 1. First Embodiment (Example of splitting light into three by a diffraction element)

[0081] 2. Second implementation method (example of splitting light into five by means of a diffraction element)

[0082] 3. Third implementation method (example of splitting light into seven segments using a diffraction element)

[0083] 4. Fourth Implementation (Example of splitting light into nine segments using a diffraction element)

[0084] 5. Fifth Implementation Method (Modified Example)

[0085] 6. Sixth Implementation Method (Application Example)

[0086] <1. First Implementation Method>

[0087] [Composition of the distance measuring device]

[0088] Figure 1 This is a block diagram illustrating an example of the overall configuration of the ranging device 10 in an embodiment of the present technology.

[0089] The distance measuring device 10 is a device that measures the distance to the illuminated object 20 by illuminating the object 20 with illumination light and receiving the reflected light. The distance measuring device 10 is provided with an illumination unit 100, a light receiving unit 200, a control unit 300, and a distance measuring unit 400.

[0090] The illumination unit 100 generates illumination light synchronously with a rectangular wave light emission control signal CLKp from the control unit 300. The light emission control signal CLKp only needs to be a periodic signal, and it is not limited to a rectangular wave. For example, the light emission control signal CLKp can be a sine wave.

[0091] The light receiving unit 200 receives reflected light from the illuminated object 20 and detects the amount of light received during each period of the vertical synchronization signal VSYNC. Multiple pixel circuits are arranged in a two-dimensional grid within the light receiving unit 200. The light receiving unit 200 provides image data (frames) corresponding to the amount of light received by these pixel circuits to the ranging unit 400. Note that the light receiving unit 200 is an example of the light detection unit described in the claims.

[0092] The control unit 300 controls the lighting unit 100 and the light receiving unit 200. The control unit 300 generates a light emission control signal CLKp and supplies it to the lighting unit 100 and the light receiving unit 200.

[0093] The ranging unit 400 measures the distance to the illuminated object 20 based on image data using a Time-of-Flight (ToF) method. The ranging unit 400 measures the distance for each pixel circuit and generates a depth map indicating the distance to the object as a layer value for each pixel. This depth map can be used, for example, for image processing that performs blurring based on the degree of distance, or for autofocus (AF) processing that obtains the focal point of a focusing lens based on distance.

[0094] [Composition of the lighting unit]

[0095] Figure 2 This is a cross-sectional view showing an example of the configuration of the lighting unit 100 in an embodiment of the present technology.

[0096] The illumination unit 100 includes a light-emitting unit 110, a collimating lens 113, and diffraction elements 114 and 134. The collimating lens 113 and the diffraction elements 114 and 134 are arranged in this order in the optical path of the light emitted from the light-emitting unit 110. Note that the order of arrangement is not limited to this.

[0097] Collimating lens 113 is an optical element that collimates the light beam emitted from light-emitting unit 110 into a substantially parallel light beam or a light beam with a predetermined angular width. Collimating lens 113 is not limited to a general optical lens, as long as it is an element with a collimating function. For example, a Fresnel lens or a superlens can also be arranged. Furthermore, if the light emitted from light-emitting unit 110 is substantially parallel and emitted in the desired direction, the optical components for collimation can be omitted. Note that collimating lens 113 is an example of the optical element described in the claims.

[0098] Diffraction elements 114 and 134 are elements that diffract a beam to separate it into multiple beams. Diffraction element 114 is tiled in a 3×3 pattern as described later. Diffraction element 134 produces diffracted light of a predetermined order as described later. Note that in this example, it is assumed that diffraction elements 114 and 134 are integrated as front and rear sides, but they could also be separate components. Note that diffraction element 114 can be omitted. Furthermore, the functions of diffraction elements 113 and 134 can be formed on the same plane. The orientation of the diffraction grating can be reversed by 180 degrees. That is, the diffraction direction described in this embodiment can be reversed by 180 degrees.

[0099] The light-emitting unit 110 is held by the holding unit 121, and the collimating lens 113, the diffraction element 114, and the diffraction element 134 are held by the holding unit 122. The holding unit 121 has, for example, a cathode electrode unit 123 and two anode electrode units 124 and 125 on the surface opposite to the surface holding the light-emitting unit 110.

[0100] For example, the light-emitting unit 110 is a surface-emitting semiconductor laser comprising multiple light-emitting elements. The multiple light-emitting elements are arranged in an array on a substrate. In this example, the optical path of light emitted from three light-emitting elements is schematically shown as representative, but in reality, as... Figure 3 As shown, light from a large number of light-emitting elements is emitted toward the object 20 being irradiated.

[0101] [Composition of the light-emitting unit]

[0102] Figure 3 This is a diagram illustrating an example of light emitted from the light-emitting unit 110 of an embodiment of the present technology.

[0103] For example, the light-emitting unit 110 has a size of approximately 1 square centimeter. In the light-emitting unit 110, for example, approximately 300 to 600 light-emitting elements 111 are arranged. For example, the light-emitting unit 110 has a light output of 1W to 5W. For example, assuming a wavelength of 940nm, but as another example, it could also be 850nm or 1.5μm.

[0104] Figure 4 This is a cross-sectional view showing an example of the configuration of the light-emitting unit 110 in an embodiment of the present technology.

[0105] For example, the light-emitting unit 110 is a front-emitting vertical-cavity surface-emitting laser (VCSEL) including a plurality of light-emitting elements 111. The plurality of light-emitting elements 111 are formed on an n-type substrate 130. The substrate 130 is mounted on a component 119 containing the substrate. The component 119 containing the substrate may include a laser driver 118 for driving the light-emitting unit 110. Note that the substrate 130 is not limited to n-type and may be p-type or a high-impedance substrate.

[0106] It should be noted that although an example of a front-emitting VCSEL is shown in this article, a back-emitting VCSEL can also be used. Furthermore, the application is not limited to VCSELs and can also be applied to configurations that arrange multiple end-face emitting lasers.

[0107] [Structure of a light-emitting element]

[0108] Figure 5 This is a cross-sectional view showing a first construction example of the light-emitting element 111 in an embodiment of the present technology.

[0109] Multiple light-emitting elements 111 are arranged in an array on a substrate 130. Each light-emitting element 111 includes a semiconductor layer 140, which, on the front side of the substrate 130, sequentially includes a lower distributed Bragg reflector (DBR) layer 141, a lower spacer layer 142, an active layer 143, an upper spacer layer 144, an upper DBR layer 145, and a contact layer 146. Specifically, a portion of the lower DBR layer 141, lower spacer layer 142, active layer 143, upper spacer layer 144, upper DBR layer 145, and contact layer 146 forms a columnar mesa 147 on the upper part of the semiconductor layer 140. Within the mesa 147, a light-emitting region 143A is formed at the center of the active layer 143. Furthermore, the upper DBR layer 145 is provided with a current concentration layer 148 and a buffer layer 149.

[0110] Substrate 130 is, for example, an n-type GaAs substrate. Examples of n-type impurities include, for example, silicon (Si), selenium (Se), etc. For example, semiconductor layer 140 includes various AlGaAs-based compound semiconductors. Here, AlGaAs-based compound semiconductors are compound semiconductors that contain at least aluminum (Al) and gallium (Ga) among the group 3B elements in the short-period periodic table and at least arsenic (As) among the group 5B elements in the short-period periodic table. Note that other materials may also be used depending on the wavelength.

[0111] An annular upper electrode 151, including a light-emitting port 151A, is formed on the upper surface of the contact layer 146, which serves as the upper surface of the mesa 147. Furthermore, an insulating layer is formed on the side and peripheral surfaces of the mesa 147. The upper electrode 151 is connected via lead wires to an electrode unit disposed on the front side of the holding unit 121, and is electrically connected to anode electrode units 124 and 125 disposed on the back side of the holding unit 121.

[0112] The lower electrode 152 is disposed on the back side of the substrate 130. The lower electrode 152 is electrically connected to the cathode electrode unit 123 disposed on the back side of the holding unit 121.

[0113] Note that although this example describes an instance in which the cathode electrode is made as a common electrode and the anode electrode is separately disposed, depending on the structure of the light-emitting element 111, the anode electrode can also be made as a common electrode and the cathode electrode can be separately disposed.

[0114] Figure 6 This is a cross-sectional view showing a second construction example of the light-emitting element 111 in an embodiment of the present technology.

[0115] The light-emitting element 111 in the second embodiment is a multi-junction VCSEL, and has a structure in which a P-DBR layer 171, an active layer 172, a tunnel junction 173, an active layer 174, and an N-DBR layer 175 are stacked sequentially from the emitting side. That is, two pn junctions are connected, and active layers (active regions) 172 and 174 emitting laser oscillation wavelengths are stacked in the vertical direction between them. By arranging multiple active layers 172 and 174 in this way, the light output of each light-emitting element 111 can be improved (see Zhu Wenjun et al., “Analysis of the operation point of a Novel Multiple-Active Region Tunneling-Regenerated vertical-Cavity Surface-Emitting Laser”, Proc. of International Conference on Solid-State and Integrated Circuit Technology, Vol. 6, pp. 1306-1309, 2001). According to this multi-junction VCSEL, the size and cost of the device can be reduced. Note that although omitted in the second construction example, similar to the first construction example, spacer layers, buffer layers, current concentration layers, mesas, light-emitting ports, upper electrode layers, and lower electrode layers can be set near the active layer.

[0116] In this embodiment of the technology, because the spot light is divided by the diffraction element 134, the number of spots can be increased while maintaining or enhancing the light intensity of the spot light by combining it with a multi-junction VCSEL. Therefore, both ranging accuracy and ranging resolution can be satisfied.

[0117] [Flat Tile]

[0118] Figure 7 This is a diagram illustrating an example of the illumination pattern of the diffraction element 114 in an embodiment of the present technology.

[0119] The diffraction element 114 separates each beam emitted from the light-emitting unit 110 and then collimated by the collimating lens 113 into multiple beams. In this example, for each beam in the central quadrilateral, copies are generated in eight directions—vertical, horizontal, and inclined—and a 3×3 tiling is performed.

[0120] Conversely, diffraction element 134 generates diffracted light of a predetermined order for each beam tiled by diffraction element 114, as described later.

[0121] [Structure of a diffraction element]

[0122] Figure 8This is a diagram illustrating a construction example of the diffraction element 134 in the first embodiment of the present technology.

[0123] In the first embodiment, it is assumed that the light is split into three by the diffraction element 134. Therefore, the diffraction element 134 uses a diffraction grating obtained by providing fine parallel slits on a plane such as glass. Thus, the diffraction element 134 generates diffracted light in one direction relative to the illumination pattern of the diffraction element 114.

[0124] [Arrangement of light-emitting elements]

[0125] Figure 9 This is a diagram illustrating an example of the arrangement of light-emitting elements 111 in the light-emitting unit 110 of an embodiment of the present technology.

[0126] As described above, a plurality of light-emitting elements 111 are arranged in the light-emitting unit 110. The light-emitting unit 110 has a structure of multiple arrays based on the arrangement of the light-emitting elements 111 at the vertices A, B, C, and D of a quadrilateral and at the point O where the diagonals of the quadrilateral intersect, with the opposite sides of the quadrilateral being parallel to each other. Assume that the distance between the light-emitting elements 111 on the side AB (DC) in one direction is set as a, the distance between the light-emitting elements 111 on the side AD (BC) orthogonal to it is set as b, and the angle AOB formed by the two diagonals is set as θo.

[0127] [Diffraction light]

[0128] Figure 10 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 in a first embodiment of the present technology. Figure 11 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 in a first embodiment of the present technology.

[0129] In the first embodiment, it is assumed that n = 1, that is, diffracted light is generated in one direction. The diffraction element 134 generates positive first-order diffracted light 711 and negative first-order diffracted light 712 for light emitted from a light-emitting element 111 at the aforementioned point C. Therefore, a total of two diffracted lights are generated for one light-emitting element 111.

[0130] The angle θx formed between the diffraction direction and an edge AB(CD) in one direction satisfies:

[0131] θx=tan -1 (b / 3a).

[0132] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0133] φx=m·sqrt((3φa)^2+φb^2) / (2(2n+1)).

[0134] Note that the diffraction unit *m* is a unit defining the diffraction angle, and it is a natural number excluding integer multiples of 2n+1. Ideally, this diffraction unit *m* is:

[0135] m < 2n + 1.

[0136] Figures 12 to 14 This is a diagram illustrating a specific example of the light illumination spot pattern in the first embodiment of the present technology. Here, the light-emitting elements 111 are arranged in an 11×21 configuration. Figure 12 An example without diffraction element 134 is shown. Figure 13 An example is shown where the diffraction element 134 is set and the diffraction unit m is set to 1. Figure 14 An example is shown where the diffraction element 134 is set and the diffraction unit m is set to 2.

[0137] In this way, since two diffracted beams are generated for one light-emitting element 111, the number of light spots is tripled, consisting of the zero-order light generated by the light-emitting element 111 itself and the positive and negative first-order diffracted beams generated by the diffracting element 134. Furthermore, the distance between the light spots remains consistent. Therefore, the ranging resolution can be improved.

[0138] Furthermore, as the value of the diffraction unit m increases, the number of light spots in the peripheral region decreases, making it desirable for the value of the diffraction unit m to be even smaller. A diffraction unit m = 1 is particularly ideal. Conversely, when the diffraction angle is small and it is difficult to control the diffraction angle and efficiency of the diffraction element 134, the diffraction unit m can also be designed to be larger.

[0139] Note that when the diffraction element 134 is provided, a small amount of higher-order diffraction light is not generated. However, in the first embodiment of this technology, because the higher-order diffraction light overlaps with the 0th-order light or the positive first-order diffraction light and the negative first-order diffraction light from another light-emitting element, it is effectively used as a spot light.

[0140] <2. Second Implementation Method>

[0141] In this second embodiment, an example of splitting light into five parts by means of the diffraction element 134 is described. Note that the configuration other than the diffraction element 134 is similar to that of the first embodiment described above, and therefore its detailed description will be omitted.

[0142] [Structure of a diffraction element]

[0143] Figure 15 This is a diagram illustrating a construction example of the diffraction element 134 in the second embodiment of the present technology.

[0144] In the second embodiment, it is assumed that the light is split into five by the diffraction element 134. Therefore, a diffraction optical element (DOE) obtained by forming a fine grating shape on a plane such as glass is used as the diffraction element 134. Thus, the diffraction element 134 generates diffracted light in two directions in response to the illumination pattern of the diffraction element 114.

[0145] [Diffraction light]

[0146] Figure 16 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 in a second embodiment of the present technology. Figure 17 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 in a second embodiment of the present technology.

[0147] In the second embodiment, it is assumed that n = 2, that is, diffracted light is generated in two directions. The diffraction element 134 generates positive first-order diffracted light and negative first-order diffracted light in each of the two directions for light emitted from a light-emitting element 111 at the aforementioned point C. Therefore, a total of four diffracted lights are generated for one light-emitting element 111.

[0148] The angle θx formed between a diffraction direction and sides AB(CD) in that direction satisfies:

[0149] θx=tan -1 (b / 3a).

[0150] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0151] φx=m·sqrt((3φa)^2+φb^2) / (2(2n+1)).

[0152] The angle θx formed between the other diffraction direction and the side AB(CD) in one direction satisfies:

[0153] θx=tan -1 (-3b / a).

[0154] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0155] φx=m·sqrt(φa^2+(3φb)^2) / (2(2n+1)).

[0156] Note that, as mentioned above, the diffraction unit m is a natural number that does not include integer multiples of 2n+1.

[0157] Figures 18 to 21This is a diagram illustrating a specific example of a light-illuminating spot pattern in the second embodiment of the present technology. Figure 18 An example is shown where the diffraction unit m is set to 1. Figure 19 An example is shown where the diffraction unit m is set to 2. Figure 20 An example is shown where the diffraction unit m is set to 3. Figure 21 An example is shown where the diffraction unit m is set to 4.

[0158] In this way, since four diffracted beams are generated for a single light-emitting element 111, the number of light spots increases fivefold due to the use of zero-order, positive first-order, and negative first-order diffracted beams. Furthermore, the distances between the light spots remain consistent. Therefore, the ranging resolution can be further improved.

[0159] Furthermore, as the value of the diffraction unit m increases, the number of light spots in the peripheral region decreases, making it desirable for the value of the diffraction unit m to be even smaller. A diffraction unit m = 1 is particularly ideal. Conversely, when the diffraction angle is small and it is difficult to control the diffraction angle and efficiency of the diffraction element 134, the diffraction unit m can also be designed to be larger.

[0160] [Variation Example]

[0161] Figure 22 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 in a modified example of the second embodiment of the present technology. Figure 23 This is a diagram illustrating an example of the diffracted light from a plurality of light-emitting elements 111 in a modified example of the second embodiment of the present technology.

[0162] In this variation, the angle θx formed by a diffraction direction and a side AB(CD) in that direction satisfies:

[0163] θx=tan -1 (b / 2a).

[0164] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0165] φx=m·sqrt((2φa)^2+φb^2) / (2(2n+1)).

[0166] The angle θx formed between the other diffraction direction and the side AB(CD) in one direction satisfies:

[0167] θx=tan -1 (-2b / a).

[0168] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0169] φx=m·sqrt(φa^2+(2φb)^2) / (2(2n+1)).

[0170] Note that the diffraction unit m is a natural number that is a multiple of 2, excluding integer multiples of 2n+1. Ideally, this diffraction unit m is:

[0171] m < 2n + 1.

[0172] Figures 24 to 25 This is a diagram illustrating a specific example of a light-irradiated spot pattern in a variation of the second embodiment of the present technology. Figure 24 An example is shown where the diffraction unit m is set to 2. Figure 25 It shows in Figure 24 An example of what happens when it is reversed 180 degrees. Figure 25 A similar embodiment to the second one described above is shown. Figure 18 The pattern.

[0173] <3. Third Implementation Method>

[0174] In this third embodiment, an example of splitting light into seven segments by means of the diffraction element 134 is described. Note that the configuration other than the diffraction element 134 is similar to that of the first embodiment described above, and therefore its detailed description will be omitted.

[0175] [Diffraction light]

[0176] Figure 26 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 in a third embodiment of the present technology. Figure 27 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 in a third embodiment of the present technology.

[0177] In the third embodiment, assuming n = 3, that is, diffracted light is generated in three directions. The diffraction element 134 generates positive first-order diffracted light and negative first-order diffracted light in each of the three directions for light emitted from a light-emitting element 111 at the aforementioned point C. Therefore, a total of six diffracted lights are generated for one light-emitting element 111.

[0178] The angle θx formed between a diffraction direction and an edge AB (CD) in a direction satisfies:

[0179] θx=tan -1 (b / 3a).

[0180] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0181] φx=m·sqrt((3φa)^2+φb^2) / (2(2n+1)).

[0182] The angle θx formed between the other diffraction direction and the side AB(CD) in one direction satisfies:

[0183] θx=tan -1 (5b / a).

[0184] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0185] φx=m·sqrt(φa^2+(5φb)^2) / (2(2n+1)).

[0186] The angle θx formed between another diffraction direction and side AB(CD) in one direction satisfies:

[0187] θx=tan -1 (-4b / 2a).

[0188] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0189] φx=m·sqrt((2φa)^2+(4φb)^2) / (2(2n+1)).

[0190] Note that, as mentioned above, the diffraction unit m is a natural number that does not include integer multiples of 2n+1.

[0191] Figures 28 to 33 This is a diagram illustrating a specific example of a light-irradiated spot pattern according to a third embodiment of the present technology. Figure 28 An example is shown where the diffraction unit m is set to 1. Figure 29 An example is shown where the diffraction unit m is set to 2. Figure 30 An example is shown where the diffraction unit m is set to 3. Figure 31 An example is shown where the diffraction unit m is set to 4. Figure 32 An example is shown where the diffraction unit m is set to 5. Figure 33 An example is shown where the diffraction unit m is set to 6.

[0192] In this way, since six diffracted beams are generated for a single light-emitting element 111, the number of light spots increases sevenfold through the zero-order diffraction, positive first-order diffraction, and negative first-order diffraction. Furthermore, the distances between the light spots remain consistent. Therefore, the ranging resolution can be further improved.

[0193] Furthermore, as the value of the diffraction unit m increases, the number of light spots in the peripheral region decreases, making it desirable for the value of the diffraction unit m to be even smaller. A diffraction unit m = 1 is particularly ideal. Conversely, when the diffraction angle is small and it is difficult to control the diffraction angle and efficiency of the diffraction element 134, the diffraction unit m can also be designed to be larger.

[0194] <4. Fourth Implementation Method>

[0195] In this fourth embodiment, an example of splitting light into nine segments by means of the diffraction element 134 is described. Note that the configuration other than the diffraction element 134 is similar to that of the first embodiment described above, and therefore its detailed description will be omitted.

[0196] [Diffraction light]

[0197] Figure 34 This diagram illustrates an example of diffracted light from a light-emitting element 111 in a fourth embodiment of the present technology. Figure 35 This diagram illustrates an example of diffracted light from a plurality of light-emitting elements 111 in a fourth embodiment of the present technology.

[0198] In the fourth embodiment, it is assumed that n = 4, that is, diffracted light is generated in four directions. The diffraction element 134 generates positive first-order diffracted light and negative first-order diffracted light in each of the four directions for light emitted from a light-emitting element 111 at the aforementioned point C. Therefore, a total of eight diffracted lights are generated for one light-emitting element 111.

[0199] The angle θx formed between a diffraction direction and an edge AB (CD) in a direction satisfies:

[0200] θx=tan -1 (b / 3a).

[0201] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0202] φx=m·sqrt((3φa)^2+φb^2) / (2(2n+1)).

[0203] The angle θx formed between the other diffraction direction and the side AB(CD) in one direction satisfies:

[0204] θx=tan -1(4b / 2a).

[0205] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0206] φx=m·sqrt((2φa)^2+(4φb)^2) / (2(2n+1)).

[0207] The angle θx formed between the other diffraction direction and the side AB(CD) in one direction satisfies:

[0208] θx=tan -1 (-3b / a).

[0209] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0210] φx=m·sqrt((φa)^2+(3φb)^2) / (2(2n+1)).

[0211] The angle θx formed between the other diffraction direction and the side AB(CD) in one direction satisfies:

[0212] θx=tan -1 (-2b / 4a).

[0213] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0214] φx=m·sqrt((4φa)^2+(2φb)^2) / (2(2n+1)).

[0215] Note that the diffraction unit m is a natural number that is a multiple of 3, excluding integer multiples of 2n+1. Ideally, this diffraction unit m is:

[0216] m < 2n + 1.

[0217] Figure 36 and Figure 37 This diagram illustrates a specific example of a light-illuminating spot pattern according to the fourth embodiment of the present technology. Figure 36 An example is shown where the diffraction unit m is set to 3. Figure 37 An example is shown where the diffraction unit m is set to 6.

[0218] In this way, since eight diffracted beams are generated for a single light-emitting element 111, the number of light spots is increased ninefold through the use of zero-order light, positive first-order diffracted light, and negative first-order diffracted light. Furthermore, the distances between the light spots remain consistent. Therefore, the ranging resolution can be further improved.

[0219] Furthermore, as the value of the diffraction unit m increases, the number of light spots in the peripheral region decreases, making it desirable for the value of the diffraction unit m to be even smaller. A diffraction unit m = 3 is particularly ideal. Conversely, in cases where the diffraction angle is small and it is difficult to control the diffraction angle and efficiency of the diffraction element 134, the diffraction unit m can also be designed to be larger.

[0220] <5. Variations>

[0221] Here, a variation of the fourth embodiment described above will be described. That is, another example in which light is split into nine by the diffraction element 134 will be described. Note that the configuration other than the diffraction element 134 is similar to that of the first embodiment described above, and therefore its detailed description will be omitted.

[0222] [First Variation]

[0223] Figure 38 This is a diagram illustrating an example of the diffracted light of the light-emitting element 111 in a first variation of an embodiment of the present technology.

[0224] In the first variation, assuming n = 4, that is, diffracted light is generated in four directions. The diffraction element 134 generates positive first-order diffracted light and negative first-order diffracted light in each of the four directions for light emitted from a light-emitting element 111 at the aforementioned point C. Therefore, a total of eight diffracted lights are generated for one light-emitting element 111.

[0225] The angle θx formed between a diffraction direction and an edge AB (CD) in a direction satisfies:

[0226] θx=tan -1 (b / a).

[0227] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0228] φx=3·sqrt(φa^2+φb^2) / (2(2n+1)).

[0229] Figure 39 This is a diagram illustrating a specific example of a light-illuminating spot pattern in a first variation of an embodiment of the present technology.

[0230] In this way, since eight diffracted beams are generated for a single light-emitting element 111, the number of light spots is increased ninefold through the use of zero-order light, positive first-order diffracted light, and negative first-order diffracted light. Furthermore, the distances between the light spots remain consistent. Therefore, the ranging resolution can be further improved.

[0231] [Second variation]

[0232] Figure 40 This is a diagram illustrating an example of the diffracted light of the light-emitting element 111 in a second variation of an embodiment of the present technology.

[0233] In the second variation, assuming n = 4, that is, diffracted light is generated in four directions. The diffraction element 134 generates positive first-order diffracted light and negative first-order diffracted light in each of the four directions for light emitted from a light-emitting element 111 at the aforementioned point C. Therefore, a total of eight diffracted lights are generated for one light-emitting element 111.

[0234] The angle θx formed between a diffraction direction and an edge AB (CD) in a direction satisfies:

[0235] θx=tan -1 (b / 2a).

[0236] When the angle difference between the two beams generated by the distances a and b between the light sources after collimation by collimating lens 113 is denoted as φa and φb respectively, the diffraction angle φx of the diffracted light satisfies:

[0237] φx=6·sqrt((2φa)^2+φb^2) / (2(2n+1)).

[0238] Figure 41 This is a diagram illustrating a specific example of a light-illuminating spot pattern in a second variation of an embodiment of the present technology.

[0239] In this way, since eight diffracted beams are generated for a single light-emitting element 111, the number of light spots is increased ninefold through the use of zero-order light, positive first-order diffracted light, and negative first-order diffracted light. Furthermore, the distances between the light spots remain consistent. Therefore, the ranging resolution can be further improved.

[0240] <6. Application Examples>

[0241] [First Application Example]

[0242] In the above embodiment, the number of light spots is increased by dividing the light spot using the diffraction element 134. In this first application example, the light-emitting elements 111 are grouped (aggregated), and the light-emitting elements 111 are switched in a time-division manner. Therefore, the emission pattern can be changed as needed. That is, switching the emission achieves multipath countermeasures while improving resolution.

[0243] [Composition of the light-emitting unit]

[0244] Figure 42 This is a diagram illustrating a configuration example of the light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0245] In this application example, the light-emitting unit 110 divides the light-emitting elements 111 arranged in columns into an X side (light-emitting element groups X1 to X9) and a Y side (light-emitting element groups Y1 to Y9). Then, the X-side electrode pad 161 and the Y-side electrode pad 162 are separately provided. Therefore, the X-side and Y-side of the light-emitting element 111 can be driven independently.

[0246] In this example, light-emitting element groups X1 to X9 and light-emitting element groups Y1 to Y9 are alternately arranged on a substrate 130 having a rectangular shape. Note that an example of alternating arrangement of light-emitting element groups X1 to X9 and light-emitting element groups Y1 to Y9 is described herein, but there is no limitation. For example, the number of multiple light-emitting elements 111 can be optionally arranged according to the desired number and position of light-emitting points and the desired light output.

[0247] Figure 43 This diagram illustrates a first example of a laser driver 118 that drives the light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0248] In the first example, the laser driver 118 is disposed on both the X and Y sides of the light-emitting element 111, and the light emission from the light-emitting element 111 is controlled by turning the switch 117 on and off. That is, by turning on one of the two switches 117 and turning off the other, the light-emitting element 111 can be switched between the X and Y sides. Note that the switch 117 is an example of the switching unit described in the claims.

[0249] Figure 44 This is a diagram illustrating a second example of a laser driver 118 for a light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0250] In this second example, the laser drivers 118 are separately configured to drive each of the X and Y sides of the light-emitting elements 111. That is, one of the two laser drivers 118 is used to drive the light-emitting element 111 on the X side, while the other is used to drive the light-emitting element 111 on the Y side. By configuring the laser drivers 118 separately in this way, driving conditions such as current and voltage can be controlled individually.

[0251] Note that in this case, switching the light emission between the X and Y sides of the light-emitting element 111 can also be performed via switch 117. Although the configuration of the cathode common circuit is described in this example, the anode common circuit is also possible, and the laser driver 118 can be arranged in each anode and switched by the operation of each laser driver.

[0252] [Diffraction light]

[0253] Figure 45 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 on the X side in a first application example of an embodiment of the present technology. Figure 46 This is a diagram illustrating an example of diffracted light from a plurality of light-emitting elements 111 on the X side in a first application example of an embodiment of the present technology. Figure 47 This is a diagram illustrating an example of diffracted light from a light-emitting element 111 on the Y side in a first application example of an embodiment of the present technology. Figure 48 This is a diagram illustrating an example of diffracted light from multiple light-emitting elements 111 on the Y side in an application example of an embodiment of this technology.

[0254] In this example, similar to the second embodiment described above, the diffraction element 134 generates positive first-order diffraction light and negative first-order diffraction light in each of the two directions for light emitted from a light-emitting element 111. Therefore, a total of four diffraction lights are generated for one light-emitting element 111. When the light-emitting element 111 on the X side and the light-emitting element 111 on the Y side alternately switch to emit light, their diffraction lights also switch simultaneously.

[0255] Figures 49 to 51 This is a diagram illustrating a specific example of a light-illuminating spot pattern in a first application example of an embodiment of the present technology. Figure 49 An example is shown where only the light-emitting element 111 on the X side is allowed to emit light. Figure 50 An example is shown where only the light-emitting element 111 on the Y side is allowed to emit light. Figure 51 An example is shown where the light-emitting element 111 on both the X and Y sides is allowed to emit light.

[0256] [operate]

[0257] Figure 52 This is a diagram illustrating an example of the timing of the operation of the light-emitting unit 110 in a first application example of an embodiment of the present technology.

[0258] In this example, assume the frame display frequency is 30Hz. That is, the display time of each frame is 33.3ms. Each frame is divided into multiple blocks. The header of each block is the period of an Automatic Power Control (APC) test pulse of 180μs, and then illumination is performed according to the signal of the corresponding block.

[0259] Regarding the control of light emission from the light-emitting element 111, three methods can be mentioned, for example. In the first method, light emission is performed alternately on the X and Y sides for each frame. Therefore, the power consumption per frame can be reduced. Furthermore, the light output in a frame can be increased to extend the ranging distance and improve ranging accuracy. In this way, ranging with improved resolution can be performed using two frames.

[0260] In the second method, light emission is performed alternately on the X and Y sides for each block. Furthermore, in the third method, which serves as an intermediate method between the first and second methods described above, light emission is performed alternately on the X and Y sides for each plurality of blocks in a switching manner.

[0261] By switching the light emission, the area not illuminated by the light spot on one side is used to detect irregularly reflected light (multipath light) returning from objects other than the target object. Then, the ranging error caused by multipath can also be corrected by subtracting the effect of the detected multipath light from the ranging value obtained by the light spot illumination.

[0262] In this example, it is assumed that the X side and Y side are switched alternately, but it is also possible to switch sequentially between only the X side, only the Y side, and between both the X and Y sides, between only the X side and both the X and Y sides, or between only the Y side and both the X and Y sides. For example, considering power consumption, it is conceivable that both emit light when the light output of each light-emitting element 111 may be low at short distances, and only when the light output of each light-emitting element 111 is expected to be high at long distances. This allows for ranging with high resolution to be performed at short distances and ranging with high distance accuracy to be performed at long distances.

[0263] [Switching between regions]

[0264] Figures 53 to 55 This is a diagram illustrating an example of a grouping of light-emitting elements 111 in a first application example of an embodiment of the present technology.

[0265] exist Figure 53 In this example, we assume a region is formed for each multiple columns (two columns in this example), and a switch is performed for each region. Figure 54 In this example, suppose a frame is further divided vertically into two to form quadrilateral regions and a switch is performed on each region. Figure 55 In the example, suppose it is vertically divided into three parts and a switch is performed on each part.

[0266] As the number of light spots increases and the light intensity of each spot is maintained, there is a possibility that power consumption will increase to the point of exceeding safety standards for eye protection. In this regard, flexible adjustments can be made by switching illumination on a region-by-region basis. Illumination switching can be performed for each frame, or for each block within a frame, etc. Furthermore, the expected location for object ranging can be identified, and illumination can be allowed in that region.

[0267] Figure 56 This is a diagram illustrating another example of the grouping of light-emitting elements 111 in a first application example of an embodiment of the present technology.

[0268] This example illustrates grouping every two columns, with one column nested between the other two. For instance, the first and third columns form region A1, the second and fourth columns form region A2, the fifth and seventh columns form region A3, the sixth and eighth columns form region A4, the ninth and eleventh columns form region A5, and the tenth and twelfth columns form region A6. Therefore, the switching of light emission can be controlled for every two columns. Thus, while employing multipath countermeasures, switching according to region can reduce power consumption and increase light output within laser safety standards.

[0269] [Second Application Example]

[0270] In this second application example, in the above embodiment, the beam shaping function is provided between the light-emitting unit 110 and the collimating lens 113.

[0271] [Composition of the lighting unit]

[0272] Figure 57 This is a cross-sectional view showing an example of the configuration of the lighting unit 100 in a second application example of an embodiment of the present technology.

[0273] In this second application example, the illumination unit 100 is provided with a light-emitting unit 110, a microlens array 116, a collimating lens 113, and diffraction elements 114 and 134. The microlens array 116, obtained by arranging multiple lenses in an array, has a beam-shaping function.

[0274] A microlens array 116 is formed on the upper surface of the light-emitting unit 110. The plurality of light-emitting elements 111 of the light-emitting unit 110 include light-emitting elements with lenses formed on their upper surface by the microlens array 116 and light-emitting elements without lenses formed on their upper surface. When the lenses of the microlens array 116 are formed on the upper surface, the illumination light from the light-emitting elements 111 becomes uniform illumination. Conversely, when the lenses of the microlens array 116 are not formed on the upper surface, the illumination light from the light-emitting elements 111 becomes spot illumination.

[0275] Figure 58 This diagram illustrates an example of the behavior of a light beam in a second application example of an embodiment of the present technology.

[0276] For example, when the lenses of the microlens array 116 are formed on its upper surface, the laser beam emitted from each of the plurality of light-emitting elements 111 is refracted by the lens surface of the microlens array 116, and a virtual light emission point is formed in the microlens array 116. In this case, the light emission points of the plurality of light-emitting elements 111 are offset and defocused in the optical axis direction, and are superimposed on the beams emitted from adjacent light-emitting elements 111, thereby performing uniform illumination. Conversely, when the lenses of the microlens array 116 are not formed on its upper surface, refraction through the lenses of the microlens array 116 does not occur, and the illumination light from the light-emitting elements 111 becomes spot illumination. Therefore, in the illumination unit 100, spot illumination and uniform illumination can be switched by switching between the light emission of one of the lenses on which the microlens array 116 is formed and the light emission of the one on which no lens is formed.

[0277] Figure 59 This is a diagram illustrating a first configuration example of the light-emitting unit 110 in a second application example of an embodiment of the present technology.

[0278] In the first configuration example, when each of the X and Y light-emitting elements emits light, a point where the four corners and opposite corners intersect each other emits light.

[0279] Figure 60 This is a diagram illustrating a second configuration example of the light-emitting unit 110 in a second application example of an embodiment of the present technology.

[0280] In this second configuration example, the number of light-emitting elements in the two groups differs from that in the first configuration example described above. In this second configuration example, the length between the light-emitting elements on the X side is twice the length on the Y side. In this case, it is desirable to form a diffraction grating pattern based on the period on the X side with a wide spacing between the light-emitting elements.

[0281] In this example, the number of light-emitting elements on the illumination side is small, the spacing between the light spots illuminating the object is widened, and the non-illumination area between the light spots used for multipath countermeasures can be sufficiently ensured. That is, when the same power is supplied to the light-emitting unit 110, the light output of each of the light-emitting elements 111 can be increased, and the number of light-emitting elements 111 on the uniform illumination side is large, thereby obtaining a more uniform light intensity distribution.

[0282] Figure 61 This is a schematic diagram illustrating an example of an illumination pattern in a second application example of an embodiment of the present technology.

[0283] In the figure, a shows the illumination pattern on the spot side. In the figure, b shows the illumination pattern on the uniformly illuminated side.

[0284] In this way, according to the embodiments of the present technology, by using the diffraction element 134 to divide the light spot, the resolution can be improved while suppressing the number of light-emitting elements 111 arranged in the optical module. Furthermore, the spacing of the light spot can be made uniform. In addition, the influence of higher-order diffracted light can be reduced.

[0285] It should be noted that the above embodiments describe examples embodying the present technology, and there is a correspondence between the matters in the embodiments and the matters specified in the claims. Similarly, there is a correspondence between the matters specified in the claims and the matters with the same names in the embodiments of the present technology. However, the present technology is not limited to the embodiments and can be embodied using various modifications of the embodiments without departing from its spirit.

[0286] Note that the effects described in this specification are merely examples and are not limited to them; other effects may also exist.

[0287] It should be noted that this technology may also have the following configurations.

[0288] (1) An optical module, comprising:

[0289] A light-emitting unit, comprising light-emitting elements arranged in a two-dimensional pattern; and

[0290] A diffraction element diffracts the light beam emitted from each of the light-emitting elements and splits the light beam into multiple beams, wherein...

[0291] The light-emitting unit has a structure of multiple arrays based on the following configuration: the light-emitting elements are arranged at the vertices of a quadrilateral, the opposite sides of the quadrilateral are parallel to each other, and the diagonals of the quadrilateral intersect at the point where they meet; the distance between the light-emitting elements on the sides in a first direction is set as 'a', and the distance between the light-emitting elements on the sides in a second direction orthogonal to the sides in the first direction is set as 'b'.

[0292] The diffraction element generates diffracted light in n directions (n ​​is a natural number), wherein the angle θx formed between a diffraction direction and the side in the first direction satisfies

[0293] θx=tan -1 (b / 3a), and

[0294] The diffraction angle φx of the diffracted light satisfies

[0295] φx=m·sqrt((3φa)^2+φb^2) / (2(2n+1))

[0296] When the angular difference between the two beams generated by the distances a and b between the light sources is set to φa and φb respectively, and m is set to a natural number that does not include integer multiples of 2n+1.

[0297] (2) The optical module according to (1) above further includes:

[0298] An optical element that converts a beam of light emitted from the light-emitting element into a generally parallel beam or a beam with a predetermined angular width.

[0299] (3) The optical module according to (1) or (2) above further includes:

[0300] The light detection unit detects reflected light from the object relative to the light beam.

[0301] (4) The optical module according to any one of (1) to (3) above, wherein

[0302] The light-emitting unit includes a switching unit, which switches the light-emitting element to emit light between at least two groups.

[0303] (5) The optical module according to any one of (1) to (4) above, wherein

[0304] Each of the light-emitting elements comprises at least two active layers in the longitudinal direction.

[0305] (6) A distance measuring device, comprising:

[0306] A light-emitting unit, comprising light-emitting elements arranged in two dimensions;

[0307] A diffraction element that diffracts the light beam emitted from each of the light-emitting elements and splits the light beam into multiple beams;

[0308] A light detection unit that detects reflected light from an object relative to the light beam; and

[0309] The ranging unit measures the distance from the beam and reflected light to the object, whereby...

[0310] The light-emitting unit has a structure of multiple arrays based on the following configuration: the light-emitting elements are arranged at the vertices of a quadrilateral, the opposite sides of the quadrilateral are parallel to each other, and the diagonals of the quadrilateral intersect at the point where they meet; the distance between the light-emitting elements on the sides in a first direction is set as 'a', and the distance between the light-emitting elements on the sides in a second direction orthogonal to the sides in the first direction is set as 'b'.

[0311] The diffraction element generates diffracted light in n directions (n ​​is a natural number), wherein the angle θx formed between a diffraction direction and the side in the first direction satisfies

[0312] θx=tan -1 (b / 3a), and

[0313] The diffraction angle φx of the diffracted light satisfies

[0314] φx=m·sqrt((3φa)^2+φb^2) / (2(2n+1))

[0315] When the angular difference between the two beams generated by the distances a and b between the light sources is set to φa and φb respectively, and m is set to a natural number that does not include integer multiples of 2n+1.

[0316] Reference Symbol List

[0317] 10 Distance measuring device

[0318] 20 Irradiated objects

[0319] 100 lighting units

[0320] 110 light-emitting units

[0321] 111 Light-emitting element

[0322] 113 Collimating Lens

[0323] 114 Diffraction element

[0324] 117 switch

[0325] 118 Laser Driver

[0326] 119 Components including a substrate

[0327] 121, 122 Holding Units

[0328] 123 Cathode Electrode Unit

[0329] 124, 125 Anode electrode units

[0330] 130 base

[0331] 134 Diffraction element

[0332] 161, 162 electrode pads

[0333] 200 optical receiving units

[0334] 300 Control Unit

[0335] 400 ranging units.

Claims

1. An optical module, comprising: A light-emitting unit includes light-emitting elements arranged in a two-dimensional direction; as well as A diffraction element that diffracts the light beam emitted from each of the light-emitting elements and separates the light beam into multiple beams, wherein... The light-emitting unit is based on a plurality of array structures constructed in which the light-emitting elements are arranged at the vertices of quadrilaterals and at the points where the diagonals of the quadrilaterals intersect, the facing sides of the quadrilaterals being parallel to each other, wherein the distance between the light-emitting elements on the sides in a first direction is set as 'a', and the distance between the light-emitting elements on the sides in a second direction orthogonal to the sides in the first direction is set as 'b'. The diffraction element generates diffracted light in n directions, where n is a natural number, and an angle θx formed between a diffraction direction and an edge in the first direction satisfies... θx=tan -1 (b / 3a), and When the angular difference between the two beams generated by the distances a and b between the light sources is set to... a and b, and m is set to a natural number that is not a multiple of 2n+1, the diffraction angle of the diffracted light. x satisfies x=m sqrt((3 a)^2+ b^2) / (2(2n+1))。 2. The optical module according to claim 1, further comprising: An optical element that converts a beam of light emitted from the light-emitting element into a generally parallel beam or a beam with a predetermined angular width.

3. The optical module according to claim 1, further comprising: The light detection unit detects the reflected light from the object relative to the light beam.

4. The optical module according to claim 1, wherein, The light-emitting unit includes a switching unit that switches the light-emitting element that should emit light at every two sets.

5. The optical module according to claim 1, wherein, Each of the light-emitting elements comprises at least two active layers in the longitudinal direction.

6. A distance measuring device, comprising: A light-emitting unit includes light-emitting elements arranged in a two-dimensional direction; A diffraction element that diffracts the light beam emitted from each of the light-emitting elements and separates the light beam into multiple light beams; A light detection unit detects the reflected light from the object in relation to the light beam; as well as The ranging unit measures the distance to the object based on the light beam and the reflected light, wherein... The light-emitting unit is based on a plurality of array structures constructed in which the light-emitting elements are arranged at the vertices of quadrilaterals and at the points where the diagonals of the quadrilaterals intersect, the facing sides of the quadrilaterals being parallel to each other, wherein the distance between the light-emitting elements on the sides in a first direction is set as 'a', and the distance between the light-emitting elements on the sides in a second direction orthogonal to the sides in the first direction is set as 'b'. The diffraction element generates diffracted light in n directions, where n is a natural number, and an angle θx formed between a diffraction direction and an edge in the first direction satisfies... θx=tan -1 (b / 3a), and When the angular difference between the two beams generated by the distances a and b between the light sources is set to... a and b, and m is set to a natural number that is not a multiple of 2n+1, the diffraction angle of the diffracted light. x satisfies x=m sqrt((3 a)^2+ b^2) / (2(2n+1))。

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