Distance sensor, display device, electronic device and distance detection method

Patent metadata

Field	Value
Publication number	US-10991298-B2
Application number	US-201916695144-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Aug 19, 2019
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

A distance sensor includes: a shell; and at least two infrared light emission devices, a light sensor and a light wall structure, which are arranged within a space enclosed by the shell. Each of the at least two infrared light emission devices emits light to a set range, and the set ranges corresponding to respective infrared light emission devices have an overlapping region beyond a preset height, a luminous flux density in the overlapping region exceeds a set density threshold value, and a luminous flux density outside the overlapping region is less than the set density threshold value. The light sensor is arranged in a preformed groove of the light wall structure. The light wall structure can be made from a light absorption material and configured to prevent incidence of light around to the light sensor.

First claim

The invention claimed is:

1. A distance sensor, comprising: a shell; and at least two infrared light emission devices, a light sensor and a light wall structure, which are arranged within a space enclosed by the shell,
wherein each of the at least two infrared light emission devices emits light to a set range, and the set ranges corresponding to respective infrared light emission devices have an overlapping region beyond a preset height, wherein a luminous flux density in the overlapping region exceeds a set density threshold value, and a luminous flux density outside the overlapping region is less than the set density threshold value, wherein the set density threshold value is a critical value corresponding to a luminous flux density of the light emitted by the infrared light emission device that excites a pixel to emit light;
the light sensor is arranged in a preformed groove in the light wall structure; and
the light wall structure is made from a light absorption material and configured to prevent incidence of ambient light to the light sensor and prevent the light emitted by the at least two infrared light emission devices from directly entering the light sensor without being reflected.

2. The distance sensor of claim 1 , further comprising a controller, wherein the controller is configured to turn on or turn off the light sensor and the at least two infrared light emission devices according to an external control signal.

3. The distance sensor of claim 1 , wherein an arrangement manner for the at least two infrared light emission devices comprises one of: arrangement in rows, arrangement in columns, or arrangement according to a set pattern.

4. The distance sensor of claim 1 , wherein the at least two infrared light emission devices are powered by a same power supply.

5. The distance sensor of claim 1 , wherein a wavelength of the light emitted by the at least two infrared light emission devices is within a range from 940 nm to 1,000 nm.

6. The distance sensor of claim 1 , wherein the light sensor is configured to, after being turned on, perform photoelectric conversion to obtain a photovoltage and calculate a distance between an object and the distance sensor according to the photovoltage and a preset relationship curve between photovoltages and distances.

7. The distance sensor of claim 1 , wherein the light sensor is configured to, after being turned on, perform photoelectric conversion to obtain a photovoltage, calculate a grayscale result corresponding to the photovoltage according to the photovoltage and a preset table of correspondences between photovoltages and grayscale results, and output the grayscale result to a processor so that the processor can calculate a distance between an object and the distance sensor based on a relationship curve between the grayscale results and distances.

8. A display device, comprising an Organic Light-Emitting Diode (OLED) display screen and the distance sensor of claim 1 , wherein the distance sensor is arranged on a substrate of the OLED display screen and on a side far away from a light output direction of the OLED display screen.

9. The display device of claim 8 , wherein the OLED display screen comprises a driving circuit of the display screen, wherein the driving circuit is configured to, after outputting a driving signal to a specified row of pixels, send a synchronization signal to a controller of the distance sensor, the synchronization signal being taken as an external control signal of the controller.

10. The display device of claim 8 , wherein the preset height is more than or equal to a thickness of the OLED display screen.

11. The display device of claim 8 , wherein a protective layer is arranged between the OLED display screen and the distance sensor, the protective layer is provided with one or more holes at positions corresponding to the distance sensor, and the holes are configured to transmit light emitted by and light received by the distance sensor.

12. An electronic device, comprising the display device of claim 8 .

13. The electronic device of claim 12 , further comprising:
a processor; and
memory configured to store an instruction executable by the processor,
wherein the processor is configured to execute the executable instruction in the memory to perform operations of:
acquiring a synchronization signal sent by a driving circuit of a display screen; and
controlling a distance sensor for distance detection,
wherein controlling the distance sensor for distance detection comprises:
responsive to the acquiring the synchronization signal, starting timing;
after a first set duration elapses since the starting of the timing, controlling the distance sensor to be turned on, emitting light by an infrared light emission device in the distance sensor, and detecting reflected light by a light sensor in the distance sensor;
after a second set duration elapses since the distance sensor is turned on, controlling the distance sensor to be turned off, and acquiring result data output by the distance sensor; and
determining an actual distance of a detected object according to the result data based on a preset relationship curve between result data and distances.

14. A mobile phone, comprising the distance sensor of claim 1 , wherein each of the at least two infrared light emission devices is prevented from exciting the display screen to display a light spot.

15. A distance detection method, comprising:
acquiring a synchronization signal sent by a driving circuit of a display screen; and
controlling a distance sensor for distance detection,
wherein controlling the distance sensor for distance detection comprises:
responsive to the acquiring the synchronization signal, starting timing;
after a first set duration elapses since the starting of the timing, controlling the distance sensor to be turned on, emitting light by an infrared light emission device in the distance sensor, and detecting reflected light by a light sensor in the distance sensor;
after a second set duration elapses since the distance sensor is turned on, controlling the distance sensor to be turned off, and acquiring result data output by the distance sensor; and
determining an actual distance of a detected object according to the result data based on a preset relationship curve between result data and distances.

16. The distance detection method of claim 15 , wherein the first set duration Dt is acquired through the following formula:
Dt =( L 2/ L 1)/ F,
where L2 represents a distance between the infrared light emission device in the distance sensor and a top edge of the OLED display screen, L1 represents a length from the top edge to a bottom edge of the OLED display screen, and F represents a refresh rate of the OLED display screen.

17. The distance detection method of claim 15 , wherein the second set duration At is acquired through the following formula:
At =( L 3/ L 1)/ F,
where L3 represents a width of the distance sensor in a direction from a top edge to a bottom edge of the OLED display screen, L1 represents a length from the top edge to the bottom edge of the OLED display screen, and F represents a refresh rate of the OLED display screen.

18. A non-transitory computer-readable storage medium having stored thereon computer-executable instructions that, when executed by a processor, cause the processor to implement the method of claim 15 .

Assignees

• Beijing Xiaomi Mobile Software Co Ltd

Inventors

• Chen Chaoxi
• Xie Fei
• Wang Yanteng

Classifications

• Y02B20/40

  Control techniques providing energy savings, e.g. smart controller or presence detection · CPC title

• G06F2203/04101

  2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup · CPC title

• G01S7/4813

  Housing arrangements · CPC title

• G06F2203/04108

  Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction · CPC title

• H05B47/115

  by determining the presence or movement of objects or living beings · CPC title