Image capturing device with an auto-focusing method thereof

Patent metadata

Field	Value
Publication number	US-9531945-B2
Application number	US-201514738054-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Sep 1, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An image capturing device includes a first image capturing module, a second image capturing module and a focusing and image processing module. The first image capturing module includes a plurality of first phase focusing detectors, and the field of view of the second image capturing module is smaller than the field of view of the first image capturing module. The plurality of the first phase focusing detectors are used for generating a plurality of first sets of optical sensing signals. When one of the plurality of the first sets of optical sensing signals are selected by the focusing and image processing module to provide a first focal signal according to the selected first set of optical sensing signal, the first image capturing module and the second image capturing module adjust respective focal distances according to the first focal signal.

First claim

What is claimed is:

1. An image capturing device, comprising:
a first image capturing module, comprising:
a first lens module;
a first image sensor disposed corresponding to said first lens module and comprising a plurality of first phase focusing detectors and a plurality of first image sensing pixels to provide respectively a plurality of first sets of optical sensing signals and a first image; and
a first focusing device connected to said first lens module for adjusting a position of said first lens module;
a second image capturing module, comprising:
a second lens module with a field of view smaller than a field of view of said first lens module;
a second image sensor disposed corresponding to said second lens module and comprising a plurality of second phase focusing detectors and a plurality of second image sensing pixels to provide respectively a plurality of second sets of optical sensing signals and a second image; and
a second focusing device connected to said second lens module for adjusting a position of said second lens module; and
a focusing and image processing module electrically connected to said first image capturing module and said second image capturing module;
wherein said first focusing device and said second focusing device adjust respectively a position of said first lens module and a position of said second lens module according to a first focal signal when one of said first sets of optical sensing signals are selected by said focusing and image processing module to correspondingly provide said first focal signal to said first focusing device and said second focusing device; and said first focusing device and said second focusing device adjust respectively said position of said first lens module and said position of said second lens module according to a second focal signal when one of said second sets of optical sensing signals are selected by said focusing and image processing module to correspondingly provide said second focal signal to said first focusing device and said second focusing device;
wherein said first phase focusing detectors are distributed in a first region of said first image capturing module, and said first region corresponds to a non-overlapped region of said fields of view of said first image capturing module and said second image capturing module.

2. The image capturing device of claim 1 , wherein a distribution density of said first phase focusing detectors in the first region of said first image capturing module is higher than a distribution density of said first phase focusing detectors in a second region of said first image capturing module, wherein said first region corresponds to a non-overlapped region of said fields of view of said first image capturing module and said second image capturing module, and said second region corresponds to an overlapped region of said fields of view of said first image capturing module and said second image capturing module.

3. The image capturing device of claim 1 , wherein said focusing and image processing module decides whether a contrast value of said second image being focused within a focal region is a maximal contrast value or exceeds a threshold value when said focusing and image processing module provides said first focal signal according to said one of said first sets of optical sensing signals, and drives said second focusing device to move said second lens module so that said contrast value of said second image being focused within said focal region is said maximal contrast value or exceeds said threshold value when said contrast value of said second image being focused within said focal region is not said maximal contrast value or does not exceed said threshold value, wherein one of said first phase focusing detectors that provides said selected one of said first sets of optical sensing signals corresponds to an overlapped region of said fields of view of said first image capturing module and said second image capturing module; wherein said focusing and image processing module decides whether said contrast value of said first image being focused within said focal region is said maximal contrast value or exceeds said threshold value when said focusing and image processing module provides said second focal signal according to said second sets of optical sensing signals, and drives said first focusing device to move said first lens module so that said contrast value of said first image being focused within said focal region is said maximal contrast value or exceeds said threshold value when said contrast value of said first image being focused within said focal region is not said maximal contrast value or does not exceed said threshold value, wherein one of said second phase focusing detectors that provides said selected one of said second sets of optical sensing signals corresponds to an overlapped region of said fields of view of said first image capturing module and said second image capturing module.

4. An auto-focusing method for use with an image capturing device, said image capturing device comprising a plurality of image capturing modules and a focusing and image processing module, said image capturing modules comprising a first image capturing module and a second image capturing module, a field of view of said first image capturing module being larger than a field of view of said second image capturing module, and said first image capturing module comprising a plurality of first phase focusing detectors, wherein said auto-focusing method comprises steps of:
providing a plurality of first sets of optical sensing signals from said first phase focusing detectors;
selecting one of said first sets of optical sensing signals by said focusing and image processing module to provide a first focal signal;
adjusting respective focal distances of said first image capturing module and said second image capturing module according to said first focal signal;
wherein said first phase focusing detectors are distributed in a first region of said first image capturing module, and said first region corresponds to a non-overlapped region of said fields of view of said first image capturing module and said second image capturing module.

5. The auto-focusing method of claim 4 , wherein said second image capturing module comprises a plurality of second phase focusing detectors, said auto-focusing method further comprises steps of:
providing a plurality of second sets of optical sensing signals from said second phase focusing detectors;
selecting one of said second sets of optical sensing signals by said focusing and image processing module to provide a second focal signal; and
respectively adjusting said focal distances of said first image capturing module and said second image capturing module according to said second focal signal.

6. The auto-focusing method of claim 5 , further comprising steps of:
deciding by said focusing and image processing module whether a contrast value of a second image being focused by said second image capturing module within a focal region is a maximal contrast value or exceeds a threshold value when one of said first sets of optical sensing signals are selected for focusing, wherein one of said first phase focusing detectors that provides said selected one of said first sets of optical sensing signals corresponds to an overlapped region of said fields of view of said first image capturing module and said second image capturing module; and
using contrast detection focusing by said focusing and image processing module to adjust said focal distance of said second image capturing module so that said contrast value in said second image in said focal region is said maximal contrast value or exceeds said threshold value when said contrast value of said second image in said focal region

Assignees

• Lite On Electronics Guangzhou Ltd
• Lite On Technology Corp

Inventors

• Chen Jau-Yu
• Chen Hsing-Hung

Classifications

• H04N23/45 Primary

  for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images · CPC title

• H04N23/672 Primary

  based on the phase difference signals · CPC title

• H04N23/673

  based on contrast or high frequency components of image signals, e.g. hill climbing method · CPC title

• H04N5/225

  Electricity · mapped topic

• H04N5/2258

  Electricity · mapped topic