Steerable illumination source for a compact camera
View Patent ↗A subsystem is disclosed providing a steerable-beam light source. An array of micromechanical reflectors may be disposed to selectively direct portions of light from a light source to selected targets in a scene, such as for providing composed illumination for still or video photography. The array of reflectors may be continuously steerable, thereby achieving more than the mere inefficient patterning of illumination light available from prior art projection approaches, but instead efficiently redirecting light to the desired regions of the scene. The subsystem may be sufficiently compact so as to permit integration with a compact camera into a cellular telephone, a tablet computer, a laptop computer, a digital still-image camera, a digital video-image camera, and so on. The array may be operated in conjunction with a camera controller to selectively illuminate one or more targets of focus or zoom, omit illumination of undesirable image regions, etc.
1. An optical compact illumination system comprising:
a two-part substrate comprising a first and second part;
wherein the first part comprises:
a first surface proximate which is disposed a light source for issuing a light beam; and
a second surface over which is disposed an array comprising a plurality of addressable reflectors, each continuously steerable within at least one degree of freedom, disposed such that said light beam is incident upon said array, wherein each said reflector is configured for redirecting a different portion of said light beam into a desired non-convergent light path, wherein said array of addressable reflectors comprises a plurality of rows, each said row comprises a plurality of addressable reflectors, a first of said rows having addressable reflectors of a first physical dimension or a first shape and a second of said rows having addressable reflectors of a second physical dimension or a second shape, the first physical dimension and the second physical dimension being different and the first shape and the second shape being different;
wherein the second part comprises:
a first surface disposed proximate the array;
a second surface over which is formed a reflective surface, and wherein each said addressable reflector is a lens disposed such that a portion of the light from said light source may be independently directed thereby so as to be incident upon said reflective surface; and
a third surface of the second part through which the portion of the light incident upon said reflective surface is selectively directed to or away from a target in a scene to be photographed.
2. The system of claim 1 , wherein each said plurality of addressable reflectors are independently addressable.
3. The system of claim 1 , wherein said light source is disposed to emit light substantially along a first axis, and further wherein said addressable reflectors are disposed such that light from said light source is reflected along a path that is rotated between 45 degrees and 135 degrees out of said first axis.
4. The system of claim 1 , further comprising a magnetic actuator array, wherein each said addressable reflector may be actuated by said magnetic actuator array.
5. The system of claim 4 , wherein each said addressable reflector has a corresponding magnetic actuator in said magnetic actuator array.
6. The system of claim 1 , further comprising a plurality of electrodes associated with each said addressable reflector such that each said addressable reflector may be independently positioned by electrostatic actuation of at least one of said electrodes.
7. The system of claim 1 , wherein said array of addressable reflectors comprises a plurality of rows, each said row comprises a plurality of said addressable reflectors, a first of said rows having a first number of addressable reflectors and a second of said rows having a second number of addressable reflectors, the first number and the second number being different.
8. An optical subsystem for providing a steerable-beam light source, comprising:
a two-part substrate comprising a first and second part;
wherein the first part comprises:
an optically transparent substrate;
a first surface proximate which is disposed a light source for directing light generated thereby into said optically transparent substrate; and
a second surface over which is disposed an array comprising a plurality of independently addressable optical elements disposed such that light from said light source received through said transparent substrate is incident upon said array, each said independently addressable optical element capable of independently redirecting a portion of said light from said light source into a desired light path; and
wherein the second part comprises:
a first surface disposed proximate the array;
a second surface over which is formed a reflector disposed proximate said transparent substrate, and wherein each said independently addressable optical element is a lens disposed such that a portion of the light from said light source may be independently directed thereby so as to be incident upon said reflector; and
a third surface of the second part through which the portion of the light incident upon said reflector is selectively directed to or away from a target in a scene to be photographed.
9. The subsystem of claim 8 , wherein each said independently addressable optical element is a mirror.
10. The subsystem of claim 8 , wherein said light source is disposed to emit light substantially along a first axis, and further wherein said independently addressable optical elements are disposed such that light from said light source is reflected into a path that is rotated between 45 degrees and 135 degrees out of said first axis.
11. The subsystem of claim 10 , wherein at least a first portion of said light is reflected by at least a first of said elements and at least a second portion of said light is reflected by at least a second of said elements.
12. The subsystem of claim 8 , wherein said light source is disposed to emit light substantially along a first axis, and further wherein said independently addressable optical elements are disposed such that light from said light source is collimated around a second axis that is not parallel to said first axis.
13. The subsystem of claim 8 , further comprising a magnetic actuator array, wherein each said independently addressable optical element may be actuated by said magnetic actuator array.
14. The subsystem of claim 13 , wherein each said independently addressable optical element has a corresponding magnetic actuator in said magnetic actuator array.
15. The subsystem of claim 8 , further comprising a plurality of electrodes associated with each said independently addressable optical element such that each said independently addressable optical element may be independently positioned by electrostatic actuation of at least one of said electrodes.
16. The subsystem of claim 8 , wherein said array comprises a plurality of rows, each said row comprises a plurality of said optical elements, a first of said rows having a first number of optical elements and a second of said rows having a second number of optical elements, the first number and the second number being different.
17. The subsystem of claim 8 , wherein said array comprises a plurality of rows, each said row comprises a plurality of said optical elements, a first of said rows having optical elements of a first dimension and a second of said rows having optical elements of a second dimension, the first dimension and the second dimension being different.
18. The subsystem of claim 8 , wherein said array comprises a plurality of rows, each said row comprises a plurality of said optical elements, a first of said rows having optical elements of a first shape and a second of said rows having optical elements of a second shape, the first shape and the second shape being different.
19. The subsystem of claim 8 , further comprising:
an actuator array, whereby said independently addressable optical elements may be actuated by said actuator array;
an array controller, communicatively coupled to said actuator array, for controlling actuation of said independently addressable optical elements;
an image controller for controlling selection of an element of a scene for image capture; and
wherein said array controller is communicatively coupled to said image controller such that a selection of an element by said image controller produces a corresponding actuation of said independently addressable optical elements to selectively illuminate said selected element of said scene.
20. A compact camera including a flash system, comprising:
a steerable illumination housing;
an image capture subsystem disposed within said steerable illumination housing, said image capture subsystem capable of selectively focusing a light beam on one or more targets of a scene for an image capture operation;
wherein the steerable illumination housing comprises:
a light source disposed within said steerable illumination housing;
an optical element for total internal reflection of a light from the light source, wherein the optical element has a first surface proximate the light source;
an array proximate to a second surface of the optical element comprising a plurality of addressable reflectors, each reflector continuously steerable within at least two degrees of freedom, carried by said steerable illumination housing and disposed such that said light beam is incident upon said array, wherein each said reflector is configured for redirecting a different portion of said light beam through a substrate that exists between the second surface and the array into a desired light path of the optical element so as to exit said steerable illumination housing at a third surface and selectively directed toward or away from each of said one or more targets; and
wherein the second surface and third surface are oriented at an angle relative to one another.
21. The compact camera of claim 20 , wherein said compact camera forms a portion of a device selected from the group consisting of: a cellular telephone, a tablet computer, a laptop computer, a digital still-image camera, and a digital video-image camera.
22. The subsystem of claim 20 , wherein each said reflector may independently redirect a portion of said light from said light source into a desired light path such that each said light path is directed to a selected one of said targets.
23. The subsystem of claim 20 , further comprising:
an actuator array, whereby said reflector may be actuated by said actuator array;
an array controller, communicatively coupled to said actuator array, for controlling actuation of said reflectors;
an image controller for controlling selection of an element of a scene for image capture by said image capture subsystem; and
wherein said array controller is communicatively coupled to said image controller such that a selection of an element by said image controller produces a corresponding actuation of said reflectors to selectively illuminate said selected element of said scene.