Thin psd for laser-scanning systems

Patent metadata

Field	Value
Publication number	US-2016265902-A1
Application number	US-201615065904-A
Country	US
Kind code	A1
Filing date	Mar 10, 2016
Priority date	Mar 12, 2015
Publication date	Sep 15, 2016
Grant date	—

Abstract

Embodiments described include a system comprising a position sensing device (PSD) and a light source. The light source is configured to, by passing one or more light beams through the PSD, cause one or more electrical currents to flow through the PSD. The system further comprises a processor, configured to (i) in response to the electrical currents, ascertain an amount of power that is delivered by the light source, and (ii) in response to the amount of power exceeding a threshold amount of power, inhibit the light source from further operation. Other embodiments are also described.

First claim

1 . A system, comprising:
a position sensing device (PSD); a light source, configured to, by passing one or more light beams through the PSD, cause one or more electrical currents to flow through the PSD; and a processor, configured to:
in response to the electrical currents, ascertain an amount of power that is delivered by the light source, and
in response to the amount of power exceeding a threshold amount of power, inhibit the light source from further operation.

2 . The system according to claim 1 , wherein the light source is a laser, and further comprising a laser-scanning module comprising the laser, the PSD being positioned at an exit aperture of the laser-scanning module.

3 . The system according to claim 2 ,
wherein the laser-scanning module is configured to perform a scan by, using the laser, emitting a plurality of light beams that include the one or more light beams, and wherein the processor is configured to inhibit the laser from further operation by aborting the scan.

4 . The system according to claim 3 , wherein the processor is configured to
ascertain the amount of power that is delivered by the laser during each of a plurality of time periods over which the scan occurs, and in response to the amount of power exceeding the threshold amount of power during any one of the time periods, abort the scan before an end of a next one of the time periods.

5 . The system according to claim 2 , wherein the processor is further configured to:
in response to the electrical currents, ascertain a range of the scan, and in response to the range being narrower than a threshold range, inhibit the laser from further operation by inhibiting the laser-scanning module from repeating the scan.

6 . The system according to claim 1 , wherein the processor is configured to ascertain the ascertain the amount of power that is delivered by the light source by ascertaining an amount of power per unit area that is delivered by the light source.

7 . The system according to claim 1 , further comprising a beam-spreading element, wherein the processor is further configured to:
in response to the electrical currents, ascertain a measure of spreading by which the beam-spreading element has spread the light beams, and in response to the measure of spreading being less than a threshold measure of spreading, inhibit the light source from further operation.

8 . The system according to claim 7 , wherein the beam-spreading element is selected from the group consisting of: a diffractive optical element, and an optical diffuser.

9 . The system according to claim 1 , wherein the PSD comprises a photosensitive material comprising a thin region having a thickness of less than 10 μm, the light source being configured to pass the one or more light beams through the thin region of the photosensitive material.

10 . The system according to claim 9 , wherein the photosensitive material comprises a material selected from the group consisting of: silicon, indium gallium arsenide, and germanium.

11 . The system according to claim 9 , wherein the photosensitive material is organic.

12 . The system according to claim 9 , wherein the thin region of the photosensitive material is at least partly surrounded by a thicker region of the photosensitive material having a thickness that is greater than the thickness of the thin region.

13 . The system according to claim 9 , wherein the thickness of the thin region of the photosensitive material is less than 5 μm.

14 . The system according to claim 9 , further comprising an optically transparent support, which is configured to provide structural support to the thin region of the photosensitive material, coupled to the thin region of the photosensitive material.

15 . The system according to claim 14 , wherein the optically transparent support comprises a glass substrate.

16 . The system according to claim 14 , wherein the optically transparent support comprises an epoxy.

17 . A method for operating a light source, the method comprising:
using the light source, by passing one or more light beams through a position sensing device (PSD), causing one or more electrical currents to flow through the PSD; in response to the electrical currents, ascertaining an amount of power that is delivered by the light source; and in response to the amount of power exceeding a threshold amount of power, inhibiting the light source from further operation.

18 . The method according to claim 17 ,
wherein the light source is a laser belonging to a laser-scanning module, wherein ascertaining the amount of power that is delivered by the laser comprises ascertaining the amount of power that is delivered by the laser during at least part of a scan that is performed by the laser-scanning module, and wherein inhibiting the laser from further operation comprises inhibiting the laser from further operation by aborting the scan.

19 . The method according to claim 17 , wherein ascertaining the amount of power that is delivered by the light source comprises ascertaining an amount of power per unit area that is delivered by the light source.

20 . A position sensing device (PSD), comprising:
a photosensitive material, comprising a thin region having a thickness that is less than 10 μm; and an optically transparent support, which is configured to provide structural support to the thin region of the photosensitive material, coupled to the thin region of the photosensitive material.

Assignees

• Apple Inc

Inventors

• Nawasra Jawad
• Waldon Matthew C
• Smith Scott T
• Gregory Thomas M

Classifications

• G02B26/105

  with one or more pivoting mirrors or galvano-mirrors (G02B26/101 takes precedence) · CPC title

• G01B11/00 Primary

  Measuring arrangements characterised by the use of optical techniques · CPC title

• G02B26/127 Primary

  Adaptive control of the scanning light beam, e.g. using the feedback from one or more detectors (G02B27/0031 takes precedence) · CPC title