Compact multi-zone infrared laser illuminator

• US 10,244,181 B2
• Filed: 02/10/2016
• Issued: 03/26/2019
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: TriLumina Corp
• Inventors: Warren, Mial E.
• Primary Examiner(s): Nguyen, Tuan N
• Application Number:
  US15/040,975
• Publication Number:
  US 20160164261A1
• Time in Patent Office: 1,140 Days
• Field of Search: 372 50124, 372 50122, 372 5012, 348168, 2504951
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 5/0014 Measuring characteristics or properties thereof measuring techniques per se G01J, G01K, G01N, G01R
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/0234 Up-side down mountings, e.g. Flip-chip, epi-side down mountings or junction down mountings
• CPC Class Codes: H01S 5/02345 Wire-bonding
• CPC Class Codes: H01S 5/0237 by soldering
• CPC Class Codes: H01S 5/02469 Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC
• 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 5/04256 characterised by the configuration
• CPC Class Codes: H01S 5/04257 having positive and negative electrodes on the same side of the substrate
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18347 Mesa comprising active layer
• CPC Class Codes: H01S 5/18388 Lenses
• CPC Class Codes: H01S 5/423 having a vertical cavity
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

Methods, devices and systems are described for selectively illuminating different zones of a field of view by a multi-zone illumination device. In one aspect, a multi-zone illuminator may include a plurality of vertical cavity surface emitting lasers (VCSELs), and a plurality of micro-optical devices aligned with apertures of individual or groups of VCSELs, which are configured to be individually activated to provide adjustable illumination to different zones of a field of view of an image sensor. In another aspect, a method of selective illumination may include receiving information specifying a field of view of a camera, and controlling at least two sub arrays or individual illuminators of an illuminating array to output light at independently adjustable illumination powers, wherein each of the at least two sub arrays are independently configurable to illuminate at least one of a plurality of separate zones corresponding to the field of view of the camera.

Claims

1. An infrared illumination system, comprising:

a plurality of infrared illumination sources including a first infrared illumination source and a second infrared illumination source, the first infrared illumination source configured to provide illumination to a first zone of a plurality of zones, the second infrared illumination source configured to provide illumination to a second zone of a plurality of zones, the first zone being different than the second zone, and each of the plurality of zones corresponding to at least part of an angular portion of a field of view of an image sensor, wherein the plurality of infrared illumination sources comprise one or more arrays of a plurality of vertical-cavity surface-emitting lasers (VCSELs);

plurality of microlenses, each microlens among the plurality of microlenses corresponding to each VCSEL among the plurality of VCSELs, wherein each microlens directs illumination from a corresponding VCSEL to at least one of the plurality of separate zones; and

an image processor in communication with the plurality of infrared illumination sources and the image sensor, and configured to define an area of interest in the field of view of the image sensor and separately control each of the plurality of infrared illumination sources to provide an adjustable illumination power to at least one of the plurality of separate zones and alter an illumination of the area of interest, in response to image data indicative of an illumination of one or more areas in the field of view of the image sensor.

2. The system of claim 1, wherein the image processor is configured to:

receive image data from the image sensor; and

adjust the illumination power of at least one of the plurality of infrared illumination sources to avoid saturation of the image sensor or maximize illumination to areas of the field of view having low reflectivity.

3. The system of claim 1, wherein separately controlling each of the plurality of infrared illumination sources to provide an adjustable illumination power to at least one of the plurality of separate zones by the image processor comprises turning on or off at least one infrared illumination source.

4. The system of claim 1, wherein the image processor is configured to turn on or off a number of the plurality of infrared illumination sources sequentially or based on a timing pattern.

5. The system of claim 1, further comprising:

an electronic driver circuit in communication with the image processor and configured to adjust a current supplied to at least one of the plurality of infrared illumination sources to adjust the illumination power provided by the at least one of the plurality of infrared illumination sources.

6. The system of claim 1, wherein each VCSEL or subsets of the plurality of VCSELs have independent electrical connections to the image processor or an electronic driver circuit.

7. The system of claim 6, wherein each microlens defines a separate field of illumination for each VCSEL.

8. The system of claim 1, wherein the image processor is further configured to:

identify an object or area of interest based on image data received from the image sensor; and

turn at least one of the plurality of illumination sources off or on to provide a select illumination power to or around the identified object or area of interest.

9. The system of claim 8, wherein the system further comprises the image sensor, and wherein the image sensor or the image processor is configured to track the object or area of interest.

10. A laser array, comprising:

a plurality of vertical cavity surface emitting lasers (VCSELs) attached to a common submount, wherein individual or groups of the plurality of VCSELs are independently electrically connectable to external driver circuitry; and

a plurality of micro-optical devices aligned with apertures of the individual or the groups of the plurality of VCSELs, wherein the individual or the groups of the plurality of VCSELs are configured to be individually activated through the independent electrical connection to provide adjustable illumination to different zones of the field of view of an image sensor defined by the plurality of micro-optical devices, wherein each of the different zones corresponds to at least part of an angular portion of the field of view;

wherein a first individual or group of the plurality of VCSELs are configured to illuminate a first zone among the different zones, a second individual or group of the plurality of VCSELs are configured to illuminate a second zone among the different zones; and

wherein the illumination of at least one of the different zones of the field of view alters an illumination of an area of interest in the field of view of the image sensor, and the illumination is adjusted in response to image data indicative of an illumination of one or more areas in the field of view.

11. The laser array of claim 10, wherein the plurality of micro-optical devices comprises at least one of a micro-lens or a diffractive optic.

12. The laser array of claim 10, wherein the plurality of micro-optical devices are fabricated into a substrate of the plurality of VCSELs, wherein the plurality of VCSELs and plurality of micro-optical devices form a monolithic array.

13. The laser array of claim 10, wherein the plurality of micro-optical devices are fabricated in a separate transparent substrate.

14. The laser array of claim 10, wherein the plurality of micro-optical devices comprise a plurality of micro-lens elements, and wherein at least one micro-lens element is offset from an aperture of a first individual VCSEL or the apertures of a first subset of VCSELs among the plurality of VCSELs, wherein the offset in part defines a distinct zone or angular spread of the first individual VCSEL or the first subset of VCSELs.

15. The laser array of claim 10, wherein the plurality of VCSELs are divided into groups, and wherein adjacent groups of VCSELS do not form adjacent illumination patterns to enhance eye safety of the laser array.

16. The laser array of claim 10, wherein the plurality of VCSELs are divided into groups, and wherein the groups comprise different numbers of VCSELs to compensate for inefficient transmission from other groups with large micro-optical element offsets for illumination of at least one zone of the different zones that has a larger deviation angle from the different zones.

17. The laser array of claim 10, further comprising an external optic element aligned to the plurality of VCSELs, wherein the external optic element increases an angular separation of each of the different zones.

18. The laser array of claim 10, further comprising an external optic element aligned to the plurality of VCSELs, wherein the external optic element comprises a toroidal optical surface enabling independent adjustment of a vertical and a horizontal angular separation of the different zones.

19. The laser array of claim 10, further comprising an external diffuser aligned to the plurality of VCSELs, wherein the external diffuser increases an apparent size of the VCSELs to provide higher illumination powers within eye safety requirements.

20. A method of infrared illumination, comprising:

receiving illumination information specifying a field of view of a camera and an area of interest in the field of view;

controlling a first sub array or individual illuminator of an illuminating array to output light at independently adjustable illumination powers in a first zone of a plurality of separate zones corresponding to the area of interest in the field of view of the camera based on the received illumination information for one or more areas in the field of view of the camera; and

controlling a second sub array or individual illuminator of the illuminating array to output light at independently adjustable illumination powers in a second zone of the plurality of separate zones corresponding to the area of interest in the field of view of the camera based on the received illumination information for one or more areas in the field of view of the camera;

two or more micro-optical devices aligned with apertures of each of the first sub array individual illuminator and the second sub array or individual illuminator,

wherein the first zone is different than the second zone, wherein each of the first zone and the second zone correspond to at least part of an angular portion of the field of view, and wherein the two or more micro-optical devices direct illumination from a corresponding sub array or individual illuminator to either the first zone or the second zone.

21. The method of claim 20, wherein the two or more micro-optical devices are an offset or a micro-lens, further comprising:

configuring at least one of the offset or the micro-lens of at least one of the first sub array or individual illuminator and the second sub array or individual illuminator to define a first illumination pattern of the illuminating array.

22. The method of claim 21, wherein the configuring the at least one of the offset or the micro-lens further comprises:

configuring at least one of the offset or the micro-lens of the first sub array or individual illuminator and the second sub array or individual illuminator to provide a dispersed illumination pattern.

23. The method of claim 21, further comprising:

turning the first sub array or individual illuminator or the second sub array or individual illuminator on or off to provide the first illumination pattern.

24. The method of claim 20, further comprising:

identifying an object or area of interest based on image data received from an image sensor; and

turning at least one of the first sub array or individual illuminator and the second sub array or individual illuminator off or on to track the identified object or area of interest.