Miniature Structured Light Illuminator

• US 20160254638A1
• Filed: 02/27/2016
• Published: 09/01/2016
• Est. Priority Date: 02/27/2015
• Status: Active Grant

• Current Assignee: Princeton Optronics Inc (Ams-Osram AG)
• Original Assignee: Princeton Optronics Inc (Ams-Osram AG)
• Inventors: Chen, Tong, Ghosh, Chuni L., Seurin, Jean-Francois, Watkins, Laurence S.
• Granted Patent: US 9,553,423 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01S 5/02345 Wire-bonding
• CPC Class Codes: H01S 5/026 Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers stabilisation of output H01S5/06
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18388 Lenses
• CPC Class Codes: H01S 5/2063 obtained by particle bombardment
• CPC Class Codes: H01S 5/2072 obtained by vacancy induced diffusion
• CPC Class Codes: H01S 5/423 having a vertical cavity
• CPC Class Codes: H04N 13/204 using stereoscopic image cameras stereoscopic photography G03B35/00
• CPC Class Codes: H04N 13/207 using a single 2D image sensor
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof

Abstract

A miniature structured light illuminator is provided. The miniature structured light illuminator uses a semiconductor surface emitting array including VCSEL or RC-LED array and an array of microlens elements to generate a wide range of structured light illumination patterns. The emission beam from a surface emitter array may be selectively directed, steered, focused or expanded, by applying a lateral displacement of the microlens array, such that centers of the emission beam and microlens array are misaligned. Emitted beams may be directed through small optical components to project the structured light pattern to a distant plane. The surface emitting arrays may be configured in addressable form to be activated separately for continuous or pulsed operation with very fast pulses having <100 ps risetime. A compact structured light illuminator module with projection optics is provided in very small physical size (˜6×6×3 mm³) suitable to configure in a handheld device.

Claims

1. A compact structured light optical module comprising:

a structured light source including;

a first array of surface emitting light sources to generate one or more light beams in a pattern determined according to the array geometry and size,

at least one second array of microlenses integrated with the first array, said array of microlenses to modify divergence of said one or more light beams, wherein one or more microlens in the array is positioned with a pre-determined lateral displacement with respect to the emission axis of the one or more light beams being modified by said one or more microlens, such that said one or more light beams is proportionally deflected in a pre-determined direction to generate a structured light illumination pattern of a desired shape and size, and

one or more optical elements for projecting the said structured light illumination pattern at a distant plane.

2. The structured light optical module as in claim 1, wherein the array of surface emitting light source is one selected from a group consisting of a VCSEL array and a RC-LED array.

3. The structured light optical module as in claim 2, wherein a gain region of said surface emitting light source includes more than one gain segment for higher output power and brightness.

4. The structured light optical module as in claim 2, wherein the surface emitting light source are configured with differently shaped current confinement apertures to generate light patterns having different shapes, so as to alter microstructure of the structured light illumination pattern by selectively superimposing said light patterns having different shapes.

5. The structured light optical module as in claim 2, wherein a VCSEL array comprises VCSEL devices that are one selected from the group consisting of two-reflector, integrated three-reflector and external three-reflector VCSEL devices.

6. The structured light optical module as in claim 1, wherein the number of microlenses in the second array is substantially the same as the number of surface emitting light sources in the first array, such that each microlens is registered with a corresponding surface emitting light sources.

7. The structured light optical module as in claim 1, wherein the number of microlenses in the second array is smaller than the number of surface emitting light sources in the first array, such that each microlens in the second array is registered with a pre-determined group of surface emitting light sources in the first array.

8. The structured light optical module as in claim 1, wherein the number of microlenses in the second array is larger than the number of surface emitting light sources in the first array, such that area of the second array covers a larger area than the area of the first array to capture all the light beams emitted from the first array.

9. The structured light optical module as in claim 1, wherein the direction and extent of pre-determined displacement of each microlens in the second array is determined by the direction and extent of deflection to be generated in said one or more light beams, to achieve a desired size and shape of the structured light illumination pattern.

10. The structured light optical module as in claim 1, wherein the direction and extent of pre-determined displacement of each microlens in the second array is determined according to their position relative to the center of the first array, such that the direction and extent of deflection in said one or more light beams changes progressively to generate a desired size and shape of the structured light illumination pattern.

11. The structured light optical module as in claim 1, wherein the second array of microlenses comprise of different types of microlens that is one selected from a group consisting of convex, concave, cylindrical, aspherical, and a combination thereof, to achieve a desired size and shape of the structured light illumination pattern.

12. The structured light optical module as in claim 11, wherein the curvature of the microlenses determines the direction of the deflection of the emission beam.

13. The structured light optical module as in claim 11, wherein the asymmetry of the microlenses determines the tilt of the emission beam.

14. The structured light optical module as in claim 1, wherein the first array of surface emitting light source is integrated with a separately constructed second array of microlenses by bonding or by constructing the second array of microlenses monolithically.

15. The structured light optical module as in claim 1 configured as a sub-assembly on a printed circuit board that is flexible or rigid, to provide electrical connection to the optical module.

16. The structured light optical module as in claim 1, wherein the structured light source is configured on a submount to facilitate surface mounting with electronic components on a common printed circuit board.

17. A method of generating a structured light illumination pattern, said method comprising the steps of:

providing a structured light illumination source by integrating a first array of surface emitting light sources with a second array of microlenses to facilitate;

generating one or more light beams in a pattern determined according to the array geometry and size of the first array,

modifying the divergence of said one or more light beams by positioning one or more microlens in the array by a pre-determined displacement with respect to the emission axis of the one or more light beams being modified by respective one or more microlens, and

deflecting proportionally said one or more light beams in a pre-determined direction for generating a structured light illumination pattern of a desired shape and size.

18. The method as in claim 17, wherein said step of integrating said first array of surface emitting light sources is effected by constructing said second array of microlenses separately and bonding, or constructing the second array of microlenses monolithically.

19. The method as in claim 17, wherein said step of deflecting said one or more light beams is effected through selecting a direction and extent of pre-determined displacement of each microlens in the second array according to their position relative to the center of the first array of surface emitting light sources, thereby achieving a desired size and shape of the structured light illumination pattern.

20. The method as in claim 17, wherein said step of deflecting said one or more light beams in a desired direction is effected through selecting microlenses in the second array, from a group consisting of convex, concave, cylindrical, aspherical, and a combination thereof, to achieve a desired size and shape of the structured light illumination pattern.

21. The method as in claim 20, wherein said step of deflecting said one or more light beams in a desired direction is effected through the curvature of the microlenses in said second array.

22. The method as in claim 20, wherein said step of deflecting said one or more light beams in a desired direction includes a further step of tilting by a desired angle effected through the asymmetry of the microlenses in said second array.

23. The method as in claim 17, wherein said step of generating one or more light beams are effected by selecting a surface emitting light source from a group consisting of a VCSEL array and a RC-LED array.

24. The method as in claim 17, wherein said step of generating the structured light illumination pattern includes a further step of generating a desired microstructure effected through generating and superposing, differently shaped light patterns by configuring differently shaped current confinement apertures in VCSEL devices of said surface emitting light source.

25. The method as in claim 17, wherein said step of generating the structured light illumination pattern includes a further step of projecting said structured light illumination pattern.