US-12618665-B2 - Non-zero angle orientation of an emitter array relative to a rectilinear axis of a submount

Abstract

A structured light system includes a camera module and a dot projection module. The dot projection module includes a submount, an emitter array disposed on the submount, and a diffractive optical element (DOE) disposed over the emitter array. The emitter array includes a plurality of emitters arranged in a periodic emitter pattern and the emitter array is oriented at a non-zero angle relative to a rectilinear axis of the submount.

Inventors

• Lei Yang
• John Michael Miller
• Lijun Zhu

Assignees

• LUMENTUM OPERATIONS LLC

Dates

Publication Date

20260505

Application Date

20220121

Claims (20)

1. 1 . A structured light system, comprising: a camera module; and a dot projection module that includes: a submount, an emitter array disposed on the submount, and a diffractive optical element (DOE) disposed over the emitter array, wherein: the emitter array includes a plurality of emitters arranged in a periodic emitter pattern, and the emitter array is oriented at a first non-zero angle relative to a rectilinear axis of the submount.
2. 2 . The structured light system of claim 1 , wherein the DOE is oriented at a second non-zero angle relative to the rectilinear axis of the submount, wherein a difference between the first non-zero angle of the emitter array and the second non-zero angle of the DOE is less than a tolerance.
3. 3 . The structured light system of claim 1 , wherein a first emitter pitch of the periodic emitter pattern in an x-direction of rectilinear axes of the emitter array differs from a second emitter pitch of the periodic emitter pattern in a y-direction of the rectilinear axes of the emitter array.
4. 4 . The structured light system of claim 1 , wherein a first emitter pitch of the periodic emitter pattern in an x-direction of rectilinear axes of the emitter array matches a second emitter pitch of the periodic emitter pattern in a y-direction of the rectilinear axes of the emitter array.
5. 5 . The structured light system of claim 1 , wherein the periodic emitter pattern includes at least one of: an oblique two-dimensional emitter pattern; a rectangular two-dimensional emitter pattern; a centered rectangular two-dimensional emitter pattern; a square two-dimensional emitter pattern; or a hexagonal two-dimensional emitter pattern.
6. 6 . The structured light system of claim 1 , wherein the first non-zero angle is between 2 degrees and 30 degrees.
7. 7 . The structured light system of claim 1 , wherein the dot projection module is configured to generate a dot projection from light emitted by the plurality of emitters of the emitter array, wherein: the dot projection includes a plurality of dots that corresponds to the periodic emitter pattern; and the dot projection is oriented at a second non-zero angle relative to a rectilinear axis of a field of view of the camera module.
8. 8 . The structured light system of claim 1 , wherein the dot projection module is configured to generate a dot projection from light emitted by the plurality of emitters of the emitter array, wherein: the dot projection comprises a plurality of tiles; and each tile, of the plurality of tiles, includes a plurality of dots that conforms to a dot pattern that corresponds to the periodic emitter pattern, wherein the dot pattern is oriented at a second non-zero angle relative to a rectilinear axis of a field of view of the camera module.
9. 9 . A structured light system, comprising: a camera module; and a dot projection module configured to generate a dot projection, wherein: the dot projection includes a plurality of dots that corresponds to a periodic emitter pattern of a plurality of emitters of an emitter array of the dot projection module; and the dot projection is oriented at a first non-zero angle relative to a rectilinear axis of a field of view of the camera module.
10. 10 . The structured light system of claim 9 , wherein the first non-zero angle is between 2 degrees and 30 degrees.
11. 11 . The structured light system of claim 9 , wherein the dot projection module includes the emitter array and a submount, wherein: the emitter array is disposed on the submount; and the emitter array is oriented at a second non-zero angle relative to a rectilinear axis of the submount.
12. 12 . The structured light system of claim 11 , wherein the first non-zero angle of the dot projection matches the second non-zero angle of the emitter array.
13. 13 . The structured light system of claim 11 , wherein the dot projection module further includes a diffractive optical element (DOE) disposed over the emitter array, wherein: the DOE is oriented at approximately a zero angle relative to a rectilinear axis of the emitter array.
14. 14 . The structured light system of claim 9 , wherein: the dot projection comprises a plurality of tiles; each tile, of the plurality of tiles, includes a subset of dots of the plurality of dots; and each tile, of the plurality of tiles, is oriented at a second non-zero angle relative to the rectilinear axis of the field of view of the camera module.
15. 15 . The structured light system of claim 14 , wherein: the subset of dots conforms to a dot pattern that corresponds to the periodic emitter pattern; and the dot pattern is oriented at a second non-zero angle relative to the rectilinear axis of the field of view of the camera module.
16. 16 . A method, comprising: generating, by a dot projection module of a system, a dot projection, wherein: the dot projection includes a plurality of dots that corresponds to a periodic emitter pattern of a plurality of emitters of an emitter array of the dot projection module; and the dot projection is oriented at a first non-zero angle relative to a rectilinear axis of a field of view of a camera module of the system.
17. 17 . The method of claim 16 , wherein the first non-zero angle is between 2 degrees and 30 degrees.
18. 18 . The method of claim 16 , wherein the dot projection module includes the emitter array and a submount, wherein: the emitter array is disposed on the submount; and the emitter array is oriented at a second non-zero angle relative to a rectilinear axis of the submount.
19. 19 . The method of claim 18 , wherein the first non-zero angle of the dot projection matches the second non-zero angle of the emitter array.
20. 20 . The method of claim 16 , wherein the dot projection module further includes a diffractive optical element (DOE) disposed over the emitter array, wherein: the DOE is oriented at approximately a zero angle relative to a rectilinear axis of the emitter array.

Description

RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application No. 63/263,201, filed on Oct. 28, 2021, and entitled “DOT PROJECTOR PATTERN RANDOMNESS BY INTRODUCING A ROTATION ANGLE RELATIVE TO CAMERA AXES,” the content of which is incorporated by reference herein in its entirety. TECHNICAL FIELD The present disclosure relates generally to a structured light system and to a dot projection module of the structured light system. BACKGROUND A structured light system may include an emitter array (e.g., a vertical-cavity surface-emitting laser (VCSEL) array), a lens, and a diffractive optical element (DOE). In operation, light emitted by emitters of the emitter array is collimated by the lens, and beams of collimated light (each corresponding to a respective emitter) are directed to the DOE. The DOE distributes the collimated beams of light in order to create a dot projection (e.g., a projection of the collimated beams). More specifically, the DOE diffracts a given beam of light such that diffracted orders of the given beam are transmitted by the DOE at different angles. An angular extent of the diffraction occurs over a range of angles relative to a surface of the DOE referred to as a field of view (FOV). The FOV can be, for example, a 60 degree FOV, a 90 degree FOV, or the like. These differently directed diffracted orders form a dot projection (e.g., that includes thousands or tens of thousands of spots) in the FOV. SUMMARY In some implementations, a structured light system includes a camera module; and a dot projection module that includes: a submount, an emitter array disposed on the submount, and a diffractive optical element (DOE) disposed over the emitter array, wherein: the emitter array includes a plurality of emitters arranged in a periodic emitter pattern, and the emitter array is oriented at a first non-zero angle relative to a rectilinear axis of the submount. In some implementations, a dot projection module includes a submount; and an emitter array disposed on the submount, wherein: the emitter array includes a plurality of emitters arranged in a periodic emitter pattern, and the emitter array is oriented at a first non-zero angle relative to a rectilinear axis of the submount. In some implementations, a structured light system includes a camera module; and a dot projection module configured to generate a dot projection, wherein: the dot projection includes a plurality of dots that corresponds to a periodic emitter pattern of a plurality of emitters of an emitter array of the dot projection module; and the dot projection is oriented at a first non-zero angle relative to a rectilinear axis of a field of view of the camera module. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of an example structured light device described herein. FIG. 2 is a diagram of an example configuration of a dot projection module described herein. FIG. 3 is a diagram of an example configuration of a dot projection herein. DETAILED DESCRIPTION The following detailed description of example implementations refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. A three-dimensional (3D) sensing time of flight (ToF) device, such as a ToF camera, may include an emitter array (e.g., a vertical-cavity surface-emitting laser (VCSEL) array), a lens, and a diffractive optical element (DOE). In operation, light emitted by emitters of the emitter array (e.g., infrared (IR) light) is collimated by the lens, and beams of collimated light (each corresponding to a respective emitter) are directed to the optical element. The optical element distributes the collimated beams of light to create a dot projection (e.g., a projection of the collimated beams) on a subject. More specifically, the optical element diffracts a given beam of light such that diffracted orders of the given beam are transmitted at different angles. The 3D sensing ToF device may include one or more additional elements (e.g., one or more sensors and/or processors) to sense the dot projection and make one or more measurements concerning the subject based on the dot projection. In many cases, non-uniformity of dots of the dot projection in x and y directions of a field of view (FOV) of a ToF camera facilitates the one or more additional elements in obtaining accurate measurements concerning the subject. For example, a spacing between dots and/or a placement of a dots along (or parallel to) an axis of the FOV of the ToF camera should be non-uniform. Typically, this is achieved by randomizing locations of emitters within the emitter array. However, to obtain a particular dot count, an optical element (e.g., a DOE and/or a diffuser) is required to generate multiple high order tiles of a zero-order pattern (e.g., a projection of dots associated with the emitter array when no DOE and/or diffuser is present). Repeat tiling of the zero-order pattern reduces a non-uniformity of