# US 11,307,431 B2 · Laser projection modules and methods for detecting fracture thereof, depth cameras and electronic devices

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- Number: US 11,307,431 B2
- Document ID: US11307431B2
- Status: Granted
- Kind: B2
- Application number: 16/546,880
- Filed: 2019-08-21
- Published: 2020-01-02
- Granted: 2022-04-19
- Earliest claimed: 2018-02-27
- Assignees: Guangdong Oppo Mobile Telecommunications Corp., Ltd.
- Applicants: Guangdong Oppo Mobile Telecommunications Corp., Ltd.
- Inventors: Jian Bai; Jie Lyu; Xueyong Zhang
- Web page: https://patentgrep.com/patent/US11307431B2

## CPC

- G02B 27/4205: {having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant}
- G03B 21/2033: {LED or laser light sources}
- G02B 27/30: Collimators
- 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)}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

A laser projection module (100) and a method for detecting a fracture thereof, a depth camera (1000) and an electronic device (3000). The laser projection module (100) includes a laser emitter (10) and an optical assembly (80). The laser emitter (10) is configured to emit laser light. The laser light passes through the optical assembly (80) to form a laser pattern.

## Claims

### Claim 1

A laser projection module, comprising:
a laser emitter, configured to emit laser light;
an optical assembly, wherein the laser light passes through the optical assembly to form a laser pattern, comprising: a collimating element, configured to collimate the laser light; and a diffractive element, configured to diffract the laser light collimated by the collimating element to form the laser pattern, wherein the diffractive element is provided with a transparent conductive film, a plurality of conductive electrodes is disposed on the transparent conductive film, and the plurality of conductive electrodes is configured to output an electrical signal after being energized; and
a processor coupled to the plurality of conductive electrodes, the processor is configured to obtain the electrical signal, to determine whether the electrical signal is within a preset range, and to determine fracture of the diffractive element in response to the electrical signal being not within the preset range;
wherein the diffractive element comprises a diffractive incident surface and a diffractive exit surface which are opposed, and the transparent conductive film is disposed on the diffractive incident surface or on the diffractive exit surface;
wherein, the plurality of conductive electrodes comprises a plurality of first diffraction conductive electrodes arranged in parallel, a plurality of second diffraction conductive electrodes arranged in parallel, and a plurality of bridging diffraction conductive electrodes;
wherein each of the plurality of first diffraction conductive electrodes is continuous without interruption;
wherein each of the plurality of second diffraction conductive electrodes is interrupted with the plurality of first diffraction conductive electrodes at crisscross points, and insulated from the plurality of first diffraction conductive electrodes;
wherein each of the plurality of bridging diffraction conductive electrodes is coupled to a corresponding and interrupted second diffraction conductive electrode at breakpoints;
wherein a diffraction insulator is provided at a crisscross position between the bridging diffraction conductive electrode and the first diffraction conductive electrode; and
wherein both ends of each of the plurality of first diffraction conductive electrodes are coupled to the processor to form a conductive loop, and both ends of each of the plurality of second diffraction conductive electrodes are coupled to the processor to form a conductive loop.

### Claim 2 (depends on 1)

The module of claim 1, further comprising:
a substrate assembly comprising a substrate and a circuit board carried on the substrate, wherein the circuit board is provided with a via, and the laser emitter is carried on the substrate and accommodated in the via;
a lens barrel provided with an accommodating cavity, wherein the lens barrel comprises a first top wall and a first annular peripheral wall extending from the first top wall, the first peripheral wall is disposed on the circuit board, the first top wall is provided with a through hole communicating with the accommodating cavity, and the collimating element is accommodated in the accommodating cavity; and
a protective cover disposed on the first top wall, wherein the protective cover comprises a second top wall having a through hole for emitting and a second annular peripheral wall extending from the second top wall, the diffractive element is carried on the first top wall and accommodated in the protective cover.

### Claim 3 (depends on 1)

The module of claim 1, wherein the optical assembly is disposed on an outgoing optical path of the laser emitter, and the optical assembly is provided with a detection element; and
the laser projection module further comprises:
a circuit board assembly, comprising a circuit board and a conductive element, wherein the detection element is electrically coupled to the circuit board by the conductive element, the laser emitter is disposed on the circuit board assembly; and
a processor coupled to the circuit board; the processor being configured to receive an electrical signal output by the detection element to determine whether the optical assembly is fractured;
wherein the module further comprises a lens barrel, wherein the lens barrel is disposed on the circuit board and encloses an accommodating cavity with the circuit board, the laser emitter is accommodated in the accommodating cavity, the optical assembly comprises a diffractive element and a collimating element accommodated in the accommodating cavity, and the collimating element and the diffractive element are sequentially disposed along the outgoing optical path of the laser emitter.

### Claim 4 (depends on 3)

The module of claim 3, wherein the circuit board assembly comprises a plurality of conductive elements, the detection element comprises a transparent diffraction conductive film disposed on the diffractive element, a diffraction conductive electrode is disposed on the transparent diffraction conductive film, the diffraction conductive electrode comprises a diffraction input end and a diffraction output end, the diffraction input end is coupled to the circuit board through one of the plurality of conductive elements, and the diffraction output end is coupled to the circuit board by another one of the plurality of conductive elements; or
the circuit board assembly comprises a plurality of conductive elements, the detection element comprises diffraction conductive particles doped in the diffractive element, the diffraction conductive particles form a diffraction conductive path, the diffraction conductive path comprises a diffraction input end and a diffraction output end, the diffraction input end is coupled to the circuit board through one of the plurality of conductive elements, and the diffraction output end is coupled to the circuit board by another one of the plurality of conductive elements.

### Claim 5 (depends on 4)

The module of claim 4, wherein the plurality of conductive elements are attached to an inner surface of a peripheral wall of the lens barrel, one end of each of the plurality of conductive elements is electrically coupled to the diffraction input end or the diffraction output end, and the other end is electrically coupled to the circuit board; or
a peripheral wall of the lens barrel is provided with an annular hole in an axial direction, the plurality of conductive elements are disposed in the annular hole, and one end of each of the plurality of conductive elements is electrically coupled to the diffraction input end or the diffraction output end, and the other end is electrically coupled to the circuit board; or
a peripheral wall of the lens barrel is provided with a plurality of grooves corresponding to the plurality of conductive elements, the plurality of conductive elements are disposed in the plurality of corresponding grooves, one end of each of the plurality of conductive elements is electrically coupled to the diffraction input end or the diffraction output end, and the other end is electrically coupled to the circuit board.

### Claim 6 (depends on 3)

The module of claim 3, wherein the laser emitter comprises an edge-emitting laser, the edge-emitting laser comprises a light-emitting surface, and the light-emitting surface faces the collimating element.

### Claim 7 (depends on 6)

The module of claim 6, further comprising a fixing member, wherein the circuit board assembly further comprises a substrate, the circuit board is carried on the substrate, and the fixing member is configured to fix the edge-emitting laser on the substrate,
wherein the fixing member comprises a sealant disposed between the edge-emitting laser and the circuit board and comprising a thermal conductive adhesive, or
wherein the fixing member comprises at least two elastic support members disposed on the circuit board assembly, the at least two support members collectively form an accommodating space for accommodating the laser emitter, and the at least two support members are configured to support the laser emitter.

### Claim 8

An electronic device, comprising:
a laser projection module comprising:
a laser emitter, configured to emit laser light;
an optical assembly, wherein the laser light passes through the optical assembly to form a laser pattern, wherein the optical assembly comprises: a collimating element, configured to collimate the laser light; and a diffractive element, configured to diffract the laser light collimated by the collimating element to form the laser pattern, wherein the diffractive element is provided with a transparent conductive film, a plurality of conductive electrodes is disposed on the transparent conductive film, and the plurality of conductive electrodes is configured to output an electrical signal after being energized;
an image collector, configured to collect the laser pattern projected by the laser projection module into a target space; and
a processor, configured to obtain the electrical signal, to determine whether the electrical signal is within a preset range, and to determine fracture of the diffractive element in response to the electrical signal being not within the preset range, and to process the laser pattern to obtain a depth image;
wherein the diffractive element comprises a diffractive incident surface and a diffractive exit surface which are opposed, and the transparent conductive film is disposed on the diffractive incident surface or on the diffractive exit surface;
wherein the plurality of conductive electrodes comprises a plurality of first diffraction conductive electrodes arranged in parallel, a plurality of second diffraction conductive electrodes arranged in parallel, and a plurality of bridging diffraction conductive electrodes;
wherein each of the plurality of first diffraction conductive electrodes is continuous without interruption;
wherein each of the plurality of second diffraction conductive electrodes is interrupted with the plurality of first diffraction conductive electrodes at crisscross points, and insulated from the plurality of first diffraction conductive electrodes;
wherein each of the plurality of bridging diffraction conductive electrodes is coupled to a corresponding and interrupted second diffraction conductive electrode at breakpoints;
wherein a diffraction insulator is provided at a crisscross position between the bridging diffraction conductive electrode and the first diffraction conductive electrode; and
wherein both ends of each of the plurality of first diffraction conductive electrodes are coupled to the processor to form a conductive loop, and both ends of each of the plurality of second diffraction conductive electrodes are coupled to the processor to form a conductive loop.

### Claim 9

A method for detecting a fracture of a laser projection module, wherein the laser projection module comprises a laser emitter, a collimating element and a diffractive element, the laser emitter is configured to emit laser light, the collimating element is configured to collimate the laser light, the diffractive element is configured to diffract the laser light collimated by the collimating element to form a laser pattern;
a transparent conductive film is formed on the diffractive element, and a plurality of conductive electrodes is disposed on the transparent conductive film, and the plurality of conductive electrodes is configured to output an electrical signal after being energized;
wherein the diffractive element comprises a diffractive incident surface and a diffractive exit surface which are opposed, and the transparent conductive film is disposed on the diffractive incident surface or on the diffractive exit surface;
wherein the plurality of conductive electrodes comprises a plurality of first diffraction conductive electrodes arranged in parallel, a plurality of second diffraction conductive electrodes arranged in parallel, and a plurality of bridging diffraction conductive electrodes,
each of the plurality of first diffraction conductive electrodes is continuous without interruption,
each of the plurality of second diffraction conductive electrodes is interrupted with the plurality of first diffraction conductive electrodes at crisscross points, and insulated from the plurality of first diffraction conductive electrodes;
each of the plurality of bridging diffraction conductive electrodes is coupled to a corresponding and interrupted second diffraction conductive electrode at breakpoints;
a diffraction insulator is provided at a crisscross position between the bridging diffraction conductive electrode and the first diffraction conductive electrode; and
both ends of each of the plurality of first diffraction conductive electrodes are coupled to a processor to form a conductive loop, and both ends of each of the plurality of second diffraction conductive electrodes are coupled to the processor to form a conductive loop,
the method comprises:
obtaining a plurality of electrical signal outputs by the conductive electrodes after being energized;
determining whether each of the plurality of electrical signals is within a preset range; and
determining the fracture of the diffractive element in response to at least one of the plurality of electrical signals being not within the preset range;
wherein in response to two or more of the plurality of electrical signals being not within the preset range, determining whether the conductive electrodes corresponding to the two or more of the plurality of electrical signals are crisscrossed;
wherein in response to that the conductive electrodes corresponding to the two or more of the plurality of electrical signals are crisscrossed, determining a position of the fracture based on the conductive electrodes corresponding to the two or more of the plurality of electrical signals.