# US 12,112,493 B2 · Structured light projector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,112,493 B2 - Document ID: US12112493B2 - Status: Granted - Kind: B2 - Application number: 16/213,634 - Filed: 2018-12-07 - Published: 2020-06-11 - Granted: 2024-10-08 - Earliest claimed: 2018-12-07 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Srikanth Gurrapu; Yangxi Wang; Zhongyan Sheng - Web page: https://patentgrep.com/patent/US12112493B2 ## CPC - G03B 21/005: {Projectors using an electronic spatial light modulator but not peculiar thereto} - G06T 7/521: from laser ranging, e.g. using interferometry; from the projection of structured light - G01B 11/2513: {with several lines being projected in more than one direction, e.g. grids, patterns} - G01B 11/2536: {using several gratings with variable grating pitch, projected on the object with the same angle of incidence} - G03B 17/54: with projector - G03B 21/008: {using micromirror devices} - G06T 7/70: Determining position or orientation of objects or cameras (camera calibration G06T7/80) - G06T 2207/10028: Range image; Depth image; 3D point clouds - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract Described examples include a structured light projector including a light source. The structured light projector also includes a spatial light modulator arranged to modulate light from the light source. The structured light projector also includes a diffractive optical element arranged to modulate the light from the light source. The structured light projector further includes projection optics arranged to project the light modulated by the spatial light modulator and the diffractive optical element to a target. ## Claims ### Claim 1 An apparatus comprising: a spatial light modulator configured to produce first modulated light, wherein the first modulated light has a pixel pattern of dark pixels and bright pixels; a diffractive optical element; a lens optically coupled between the spatial light modulator and the diffractive optical element, the lens configured to focus the pixel pattern of dark pixels and bright pixels towards the diffractive optical element, wherein the diffractive optical element is configured to modulate the pixel pattern of dark pixels and bright pixels, to produce second modulated light, the second modulated light having dark regions and bright regions, the bright regions each having the pixel pattern of dark pixels and bright pixels; a camera configured to receive an image of a reflection of the second modulated light; a controller coupled to the spatial light modulator; and a processor coupled to the controller and to the camera, the processor configured to: process the image, to produce a processed image; and instruct the controller to control the spatial light modulator, based on the processed image. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the spatial light modulator is a digital micromirror device. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the second modulated light is structured light. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the processor and the controller are an integrated circuit. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the processor is a digital signal processor. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the controller is configured to instruct the spatial light modulator to vary modulation of the second modulated light. ### Claim 7 An apparatus comprising: a light source configured to produce light; a spatial light modulator optically coupled to the light source, the spatial light modulator configured to modulate the light, to produce modulated light, wherein the modulated light has a pixel pattern of dark pixels and bright pixels; a diffractive optical element; and a lens optically coupled between the spatial light modulator and the diffractive optical element, the lens configured to focus the pixel pattern of dark pixels and bright pixels towards the diffractive optical element, wherein the diffractive optical element is configured to modulate the pixel pattern of dark pixels and bright pixels, to produce a structured light pattern, the structured light pattern having dark regions and bright regions, the bright regions each having the pixel pattern of dark pixels and bright pixels. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the light source is a laser diode. ### Claim 9 (depends on 7) The apparatus of claim 7, wherein the spatial light modulator is a digital micromirror device. ### Claim 10 (depends on 7) The apparatus of claim 7, further comprising projection optics optically coupled to the diffractive optical element, the projection optics configured to project the structured light pattern, to produce projected light. ### Claim 11 (depends on 10) The apparatus of claim 10, further comprising: a camera configured to receive a reflection of the projected light; and a processor coupled to the camera, the processor configured to determine a digital representation of a target surface based on the reflection of the projected light. ### Claim 12 (depends on 11) The apparatus of claim 11, further comprising: a controller coupled to the processor and to the spatial light modulator. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the controller is configured to vary modulation of the spatial light modulator. ### Claim 14 (depends on 11) The apparatus of claim 11, wherein the camera is a charge coupled device or a complementary metal oxide semiconductor (CMOS) sensor. ### Claim 15 (depends on 11) The apparatus of claim 11, wherein the processor is configured to determine the digital representation of the target surface using epipolar analysis. ### Claim 16 (depends on 7) The apparatus of claim 7, wherein the pattern of the bright regions is shifted with respect to the pixel pattern of dark pixels and bright pixels of the modulated light. ### Claim 17 A method comprising: providing, by a light source, light; modulating, by a spatial light modulator, the light, to produce modulated light, wherein the modulated light has a pixel pattern of dark pixels and bright pixels; focusing, towards a diffractive optical element, the pixel pattern of dark pixels and bright pixels; and modulating, by the diffractive optical element, the pixel pattern of dark pixels and bright pixels, to produce a structured light pattern, the structured light pattern having dark regions and bright regions, the bright regions each having the pixel pattern of dark pixels and bright pixels. ### Claim 18 (depends on 17) The method of claim 17, wherein the spatial light modulator is a digital micromirror device. ### Claim 19 (depends on 17) The method of claim 17, wherein the modulating the light by the spatial light modulator comprises producing a first modulation pattern and producing a second modulation pattern. ### Claim 20 (depends on 17) The method of claim 17, further comprising: receiving, by a camera, a reflection of the structured light pattern, to produce an image; and processing the image to determine target points.