OPTICAL PROJECTOR WITH BEAM MONITOR

• US 20110114857A1
• Filed: 11/15/2010
• Published: 05/19/2011
• Est. Priority Date: 11/15/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: PrimeSense Ltd (Apple Inc.)
• Inventors: Akerman, Ronen, Arieli, Yoed, Voschina, Dudu, Mor, Zafrir, Segev, Tomer, Shpunt, Alexander, Galezer, Niv
• Granted Patent: US 8,492,696 B2
• Time in Patent Office: Days
• US Class Current: 250/550
• CPC Class Codes: G02B 5/1842 Gratings for image generation G02B5/1847 takes precedence
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 31/02325 the optical elements not being integrated nor being directly associated with the device
• CPC Class Codes: H01L 31/14 the light source or sources being controlled by the semiconductor device sensitive to radiation, e.g. image converters, image amplifiers or image storage devices

Abstract

Optical apparatus includes a device package, with a radiation source contained in the package and configured to emit a beam of coherent radiation. A diffractive optical element (DOE) is mounted in the package so as to receive and diffract the radiation from the radiation source into a predefined pattern comprising multiple diffraction orders. An optical detector is positioned in the package so as to receive and sense an intensity of a selected diffraction order of the DOE.

Claims

1. Optical apparatus, comprising:

a device package;

a radiation source, contained in the package and configured to emit a beam of coherent radiation;

a diffractive optical element (DOE), mounted in the package so as to receive and diffract the radiation from the radiation source into a predefined pattern comprising multiple diffraction orders; and

an optical detector, which is positioned in the package so as to receive and sense an intensity of a selected diffraction order of the DOE.

2. The apparatus according to claim 1, wherein the optical detector is configured to output a signal that is responsive to the intensity, and comprising a controller, which is coupled to receive and process the signal so as to monitor a performance of the apparatus.

3. The apparatus according to claim 2, wherein the controller is configured to inhibit an operation of the apparatus when the signal is outside a predefined range.

4. The apparatus according to claim 1, wherein the radiation source comprises a laser diode.

5. The apparatus according to claim 1, wherein the selected diffraction order is a zero order of the DOE.

6. The apparatus according to claim 5, wherein the optical detector is positioned so as to receive the zero order that is reflected back from the DOE.

7. The apparatus according to claim 6, wherein the DOE is tilted relative to an axis of the beam emitted by the radiation source so as to direct the back-reflected zero order toward the optical detector.

8. The apparatus according to claim 1, wherein the selected diffraction order is a high order of the DOE.

9. The apparatus according to claim 8, wherein the apparatus is configured to project the pattern over a predefined angular range, and wherein the optical detector is positioned to receive the radiation transmitted through the DOE at an angle that is outside the angular range.

10. An optical method, comprising:

transmitting a beam of coherent radiation through a diffractive optical element (DOE), mounted in a package, so as to diffract the radiation into a predefined pattern comprising multiple diffraction orders; and

monitoring a performance of the DOE by sensing an intensity of a selected diffraction order of the DOE using an optical detector positioned in the package.

11. The method according to claim 10, wherein monitoring the performance comprises generating a signal that is responsive to the intensity, and processing the signal so as to monitor the performance.

12. The method according to claim 11, and comprising inhibiting the beam when the signal is outside a predefined range.

13. The method according to claim 10, wherein the radiation source comprises a laser diode.

14. The method according to claim 10, wherein the selected diffraction order is a zero order of the DOE.

15. The method according to claim 14, wherein monitoring the performance comprises receiving and measuring the zero order that is reflected back from the DOE.

16. The method according to claim 15, wherein the DOE is tilted relative to an axis of the beam emitted by the radiation source so as to direct the back-reflected zero order toward the optical detector.

17. The method according to claim 10, wherein the selected diffraction order is a high order of the DOE.

18. The method according to claim 17, wherein the DOE is configured to project the pattern over a predefined angular range, and wherein monitoring the performance comprises receiving and measuring the radiation transmitted through the DOE at an angle that is outside the angular range.

19. Mapping apparatus, comprising:

a projection subassembly, comprising;

a device package;

a radiation source, contained in the package and configured to emit a beam of coherent radiation;

a diffractive optical element (DOE), mounted in the package so as to receive and diffract the radiation from the radiation source into a predefined pattern comprising multiple diffraction orders; and

an optical detector, which is positioned in the package so as to receive a selected diffraction order of the DOE and to output a signal that is response to an intensity of the selected diffraction order;

an imaging subassembly, which is configured to capture an image of the pattern that is projected onto an object; and

processing circuitry, which is configured to process the image in order to produce a three-dimensional (3D) map of the object, and to process the signal in order to monitor a performance of the DOE.