Integrated optical modules with enhanced reliability and integrity

Patent metadata

Field	Value
Publication number	US-2016356484-A1
Application number	US-201514941689-A
Country	US
Kind code	A1
Filing date	Nov 16, 2015
Priority date	Jun 3, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

An optical module includes a transparent substrate and a refractive optical element mounted on the substrate. A conductive heating trace is deposited on the substrate around the refractive optical element. A temperature sensor senses a temperature of the substrate. Control circuitry is coupled to the temperature sensor so as to measure a difference between the temperature of the substrate and a target operating temperature of the module, and to drive a current through the conductive heating trace, responsively to the difference, so as to heat the substrate to the target operating temperature.

First claim

1 . An optical module, comprising:
a transparent substrate; a refractive optical element mounted on the substrate; a conductive heating trace deposited on the substrate around the refractive optical element; a temperature sensor, configured to sense a temperature of the substrate; and control circuitry, which is coupled to the temperature sensor so as to measure a difference between the temperature of the substrate and a target operating temperature of the module, and to drive a current through the conductive heating trace, responsively to the difference, so as to heat the substrate to the target operating temperature.

2 . The module according to claim 1 , wherein the temperature sensor comprises a resistive trace deposited on the substrate in a vicinity of the refractive optical element, and wherein the control circuitry is configured to measure a resistance of the resistive trace in order to find the difference between the temperature of the substrate and the target operating temperature.

3 . The module according to claim 2 , and comprising an optical output element, which is connected to the substrate by a mechanical seal, wherein the resistive trace is deposited on the substrate beneath the mechanical seal so that the resistive trace will break upon disruption of the mechanical seal, and wherein the control circuitry is configured to inhibit operation of the optical module upon detecting, based on the resistance, that the resistive trace has broken.

4 . The module according to claim 1 , and comprising an optical output element, which is connected to the substrate by a mechanical seal, wherein the conductive heating trace is deposited on the substrate beneath the mechanical seal so that the conductive heating trace will break upon disruption of the mechanical seal, and wherein the control circuitry is configured to measure a resistance of the conductive heating trace and to inhibit operation of the optical module upon detecting, based on the resistance, that the conductive heating trace has broken.

5 . The module according to claim 1 , wherein the substrate comprises a plate having opposing first and second sides, wherein the conductive heating trace is formed on the first side and the temperature sensor is located on the second side.

6 . The module according to claim 1 , wherein the module comprises a plurality of refractive optical elements having respective optical powers, and wherein the conductive heating trace is deposited on the substrate around the refractive optical element having the greatest optical power within the plurality.

7 . The module according to claim 1 , and comprising:
an optical patterning element; and an emitter, which is configured to direct light through the module, wherein the refractive optical element focuses the light from the emitter through the optical patterning element so as to produce a pattern of structured light.

8 . An optical module, comprising:
a transparent substrate; an optical output element, which is connected to the substrate by a mechanical seal; a conductive trace deposited on the substrate beneath the mechanical seal so that the conductive trace will break upon disruption of the mechanical seal; and control circuitry, which is coupled to measure a resistance of the conductive trace and to inhibit operation of the optical module upon detecting, based on the resistance, that the conductive trace has broken.

9 . The module according to claim 8 , wherein the optical output element comprises an optical patterning element, and wherein the module comprises an emitter, which is configured to direct light through the module, which focuses the light from the emitter through the optical patterning element so as to produce a pattern of structured light.

10 . The module according to claim 9 , wherein the control circuitry is configured to shut off the emitter upon detecting that the conductive trace has been broken.

11 . A method for producing an optical module, the method comprising:
mounting a refractive optical element in a location on a transparent substrate; depositing a conductive heating trace on the substrate around the location of the refractive optical element; coupling a temperature sensor to sense a temperature of the substrate; and coupling control circuitry to the conductive heating trace and to the temperature sensor so as to measure a difference between the temperature of the substrate and a target operating temperature of the module and to drive a current through the conductive heating trace, responsively to the difference, so as to heat the substrate to the target operating temperature.

12 . The method according to claim 11 , wherein coupling the temperature sensor comprises depositing a resistive trace on the substrate in a vicinity of the refractive optical element, and wherein the method comprises measuring a resistance of the resistive trace in order to find the difference between the temperature of the substrate and the target operating temperature.

13 . The method according to claim 12 , and comprising connecting an optical output element to the substrate by a mechanical seal, wherein the resistive trace is deposited on the substrate beneath the mechanical seal so that the resistive trace will break upon disruption of the mechanical seal, and wherein the method comprises inhibiting operation of the optical module upon detecting, based on the resistance, that the resistive trace has broken.

14 . The method according to claim 11 , and comprising connecting an optical output element to the substrate by a mechanical seal, wherein the conductive heating trace is deposited on the substrate beneath the mechanical seal so that the conductive heating trace will break upon disruption of the mechanical seal, and wherein the method comprises measuring a resistance of the conductive heating trace and inhibiting operation of the optical module upon detecting, based on the resistance, that the conductive heating trace has broken.

15 . The method according to claim 11 , wherein the substrate comprises a plate having opposing first and second sides, wherein the conductive heating trace is formed on the first side and the temperature sensor is located on the second side.

16 . The method according to claim 11 , wherein the module comprises a plurality of refractive optical elements having respective optical powers, and wherein the conductive heating trace is deposited on the substrate around the refractive optical element having the greatest optical power within the plurality.

17 . The method according to claim 11 , and comprising directing light from an emitter via the optical module to an optical patterning element, wherein the refractive optical element focuses the light from the emitter through the optical patterning element so as to produce a pattern of structured light.

18 . The method according to claim 11 , and comprising:
depositing a conductive circuit trace on the substrate; connecting an optical output element to the substrate by a mechanical seal formed over the conductive circuit trace on the substrate beneath the mechanical seal so that the conductive trace will break upon disruption of the mechanical seal; and coupling control circuitry to measure a resistance of the conductive circuit trace and to inhibit operation of the optical module upon detecting, based on the resistance, that the conductive circuit trace has broken.

19 . The method according to claim 18 , wherein the optical output element comprises an optical patterning element, and whe

Assignees

• Apple Inc

Inventors

• Sawyer Kevin A
• Alnahhas Yazan Z

Classifications

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• G02B13/0065 Primary

  having a beam-folding prism or mirror · CPC title

• H04N9/3161

  using laser light sources (using laser beams scanning the display screen H04N9/3129) · CPC title

• F21V29/90 Primary

  Heating arrangements · CPC title

• G03B3/10

  Power-operated focusing · CPC title