Terminal, focusing method and apparatus, and computer readable storage medium

Patent metadata

Field	Value
Publication number	US-11516377-B2
Application number	US-202117353403-A
Country	US
Kind code	B2
Filing date	Jun 21, 2021
Priority date	Dec 11, 2018
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

The present disclosure relates to a terminal, a focusing method and apparatus. The terminal includes a ranging radar configured to obtain a reference distance between a target object to be focused and a camera module, wherein an antenna radiation angle of the ranging radar covers a viewing angle of the camera module, and wherein the camera module is configured to adjust a photographing focus of the camera module to a position where the target object is located based on the reference distance.

First claim

What is claimed is:

1. A terminal, comprising:
a ranging radar that determines a target object to be focused in a camera preview image displayed in the terminal and to detect a reference distance between the target object and a camera module provided in the terminal based on a position where the target object is located in the camera preview image,
wherein an antenna radiation angle of the ranging radar covers a viewing angle of the camera module,
wherein the camera module adjusts a photographing focus of the camera module to a position where the target object is located based on the reference distance, and
wherein the ranging radar detects the reference distance by:
determining an azimuthal angle α of the target object relative to plane X and an azimuthal angle β of the target object relative to plane Y based on the position where the target object is located in the camera preview image, wherein the plane X and the plane Y are orthogonal in a central axis of the camera module; and
detecting the reference distance between the target object and the camera module by employing the ranging radar based on the azimuthal angle α and the azimuthal angle β.

2. The terminal of claim 1 , wherein determining the azimuthal angle α of the target object relative to the plane X and the azimuthal angle β of the target object relative to the plane Y based on the position where the target object is located in the camera preview image, and detecting the reference distance between the target object and the camera module by employing the ranging radar based on the azimuthal angle α and the azimuthal angle β comprises:
establishing a coordinate system with an axis X and an axis Y, wherein the plane X is formed by the axis X and the central axis of the camera module, the plane Y is formed by the axis Y and the central axis of the camera module, and the central axis of the camera module is vertical to a plane formed by the axis X and the axis Y;
determining a line S connecting the target object and a center of the camera module;
mapping the line S to the plane X and the plane Y, determining an angle between the plane X and a line mapped to the plane V from the line S as the azimuthal angle β, and determining an angle between the plane Y and a line mapped to the plane X from the line S as the azimuthal angle α;
receiving the azimuthal angle α and the azimuthal angle β by the ranging radar, sending a radar signal to an area covered by an antenna radiation angle according to an instruction of the terminal, and receiving the radar signal reflected from an area defined by the azimuthal angle α and the azimuthal angle β; and
determining the reference distance between the target object and the terminal based on a transmission time of the radar signal and a receiving time of the radar signal reflected from the area defined by the azimuthal angle α and the azimuthal angle β.

3. The terminal of claim 1 , wherein a distance between the ranging radar and the camera module is less than or equal to a preset distance threshold.

4. The terminal of claim 1 , wherein the ranging radar is a millimeter wave radar, and the millimeter wave radar sends a radar signal via a frequency modulation continuous wave.

5. The terminal of claim 4 , wherein a frequency of the radar signal sent by the ranging radar is greater than or equal to 20 Hz, and less than or equal to 70 Hz.

6. The terminal of claim 4 , wherein a bandwidth of the radar signal sent by the ranging radar is less than or equal to 3 Hz.

7. A method for focusing, applied to a terminal, the method comprising:
detecting a reference distance between a target object to be focused and a camera module provided in the terminal by employing a ranging radar provided in the terminal; and
adjusting a photographing focus of the camera module to a position where the target object is located based on the reference distance,
wherein detecting the reference distance comprises:
determining the target object in a camera preview image displayed in the terminal; and
detecting the reference distance between the target object and the camera module by:
employing the ranging radar based on a position where the target object is located in the camera preview image;
determining an azimuthal angle α of the target object relative to plane X and an azimuthal angle β of the target object relative to plane Y based on the position where the target object is located in the camera preview image, wherein the plane X and the plane Y are orthogonal in a central axis of the camera module; and
detecting the reference distance between the target object and the camera module by employing the ranging radar based on the azimuthal angle α and the azimuthal angle β.

8. The method of claim 7 , wherein determining the azimuthal angle α of the target object relative to the plane X and the azimuthal angle β of the target object relative to the plane Y based on the position where the target object is located in the camera preview image, and detecting the reference distance between the target object and the camera module by employing the ranging radar based on the azimuthal angle α and the azimuthal angle β comprise:
establishing a coordinate system with an axis X and an axis Y, wherein the plane X is formed by the axis X and the central axis of the camera module, the plane Y is formed by the axis Y and the central axis of the camera module, and the central axis of the camera module is vertical to a plane formed by the axis X and the axis Y;
determining a line S connecting the target object and a center of the camera module;
mapping the line S to the plane X and the plane Y, determining an angle between the plane X and a line mapped to the plane Y from the line S as the azimuthal angle β, and determining an angle between the plane Y and a line mapped to the plane X from the line S as the azimuthal angle α;
receiving the azimuthal angle α and the azimuthal angle β by the ranging radar, sending a radar signal to an area covered by an antenna radiation angle according to an instruction of the terminal, and receiving the radar signal reflected from an area defined by the azimuthal angle α and the azimuthal angle β; and
determining the reference distance between the target object and the terminal based on a transmission time of the radar signal and a receiving time of the radar signal reflected from the area defined by the azimuthal angle α and the azimuthal angle β.

9. An apparatus for focusing, comprising:
a processor; and
a memory storing instructions executable by the processor,
wherein the processor is configured to:
determine a target object to be focused in a camera preview image displayed in the terminal and to detect a reference distance between the target object and a camera module based on a position where the target object is located in the camera preview image; and
adjust a photographing focus of the camera module to a position where the target object is located based on the reference distance,

wherein the processor detects the reference distance by:
determining an azimuthal angle α of the target object relative to plane X and an azimuthal angle β of the target object relative to plane Y based on the position where the target object is located in the camera preview image, wherein the plane X and the plane Y are orthogonal in a central axis of the camera module; and
detecting the reference distance between the target object and the camera module by employing the ranging radar based on the azimuthal angle α and the azimuthal angle β.

10. The apparatus of claim 9 , wherein the processor is further configured to:
establish a coordinate system with an axis X and an axis Y, wherein the plane X is formed by the axis X

Assignees

• Beijing Xiaomi Mobile Software Co Ltd

Inventors

• Hu Xiankun

Classifications

• H04N23/62 Primary

  Control of parameters via user interfaces · CPC title

• H04N23/671 Primary

  in combination with active ranging signals, e.g. using light or sound signals emitted toward objects · CPC title

• H04N23/63

  by using electronic viewfinders · CPC title

• H04N23/67

  Focus control based on electronic image sensor signals · CPC title

• G01S13/32

  using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated · CPC title