Adjusting method of camera module, lens position control device, control device of linear movement device, and controlling method of the same

Patent metadata

Field	Value
Publication number	US-10154189-B2
Application number	US-201415037410-A
Country	US
Kind code	B2
Filing date	Nov 28, 2014
Priority date	Dec 4, 2013
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

An adjusting method of a camera module, a lens position control device, a control device of a linear movement device, and a controlling method of the same are provided in a state of the cameral module in which an imaging element and an actuator are combined. The camera module includes a position sensor ( 53 ) that detects a position of a lens ( 50 ) to output a detection position signal, a storage unit ( 541 ) that stores and rewrites a position code value corresponding to the position of the lens, a target position signal generation unit ( 542 ) that outputs a target position signal based on the position code value and the target position code value, and a control unit ( 543 ) that generates a control signal based on the target position signal and the detection position signal.

First claim

The invention claimed is:

1. A calibrating method of a camera module,
the camera module comprising a lens, an imaging element that outputs an image signal of an object;
a signal processing circuit that outputs a target position code value of the lens from the image signal;
a position sensor that detects positions of the lens and outputting a detection position signal;
a lens position control circuit comprising
a storage unit that stores relationships of the lens positions and position code values to be capable of rewriting the position code values,
a target position signal generation unit that outputs a target position signal based on the position code values and the target position code value, and
a control unit that generates a control signal based on the target position signal and the detection position signal; and

a drive unit that moves the lens based on the control signal,
the method comprising:
a first step of moving the lens to a first lens position to focus on the object located at a first position for a first focus distance; and
a second step of rewriting the position code values stored in the storage unit to other position code values such that a moving range of the lens is limited based on the first focus distance to adjust a moving distance of the lens per at least one of the position code values.

2. The method of the camera module according to claim 1 , wherein the second step comprises rewriting the position code values stored in the storage unit to the other position code values such that the lens moves between the first position for a proximate focus distance and the second position for an infinite focus distance.

3. The method of the camera module according to claim 1 ,
wherein the position code values comprise a conversion code to convert the target position code to the target position signal, and the second step comprises rewriting the conversion code stored in the storage unit to limit the moving range of the lens, or
wherein the position code values comprise a matrix to convert the target position code to the target position signal, and the second step comprises rewriting the matrix stored in the storage unit to limit the moving range of the lens.

4. The method of the camera module according to claim 1 , wherein the position code values stored in the storage unit beforehand comprise a position code value corresponding to the position of the lens that moves from one end of a movable range of the lens to another end in the camera module.

5. The method of the camera module according to claim 1 , further comprising a third step of moving the lens to a second lens position to focus on the object located at a second position for a second focus distance,
wherein the second step comprises rewriting the position code value stored in the storage unit to the other position code values such that the moving range of the lens is limited based on the first focus distance and the second focus distance.

6. The method of the camera module according to claim 5 , wherein the second step comprises rewriting the position code values stored in the storage unit to the other position code values corresponding to a plurality of the positions between the first lens position and the second lens position.

7. The method of the camera module according to claim 5 ,
wherein the first focus distance is a proximate focus and the second focus distance is an infinite focus, and
wherein the second step comprises rewriting the position code values stored in the storage unit to the other position code values such that the lens moves between a plurality of the positions between the first lens position and the second lens position.

8. A calibrating method of a camera module, the camera module comprising:
a lens;
an imaging element outputting an image signal of an object;
a storage unit storing a conversion factor that can be rewritten;
a conversion unit converting the image signal with the conversion factor into a target position signal that moves the lens to a target position;
a position sensor detecting a position of the lens and outputting a detection position signal;
a control unit generating a control signal based on the target position signal and the detection position signal; and
a drive unit moving the lens based on the control signal,
the method comprising:
a first step of moving the lens to a first lens position to focus on the object located at a first position for a first focus distance;
a second step of moving the lens to a second lens position to focus on the object located at a second position for a second focus distance; and
rewriting the conversion factor stored in the storage unit to limit a moving range of the lens based on the first focus distance and the second focus distance,
wherein an adjustment signal stored in the storage unit beforehand adjusts the conversion factor such that the lens moves from one end of a movable range of the lens to another end in the camera module.

9. A calibrating method of a camera module, the camera module comprising:
a lens;
an imaging element outputting an image signal of an object;
a signal processing circuit outputting a target position code value of the lens from the image signal;
a position sensor detecting a position of the lens and outputting a detection position signal;
an adjustment unit adjusting the detection position signal with an adjustment signal that is rewritable and outputting an adjusted detection position signal;
a lens position control circuit comprising a target position signal generation unit outputting a target position signal based on the target position code value, and a control unit generating a control signal based on the target position signal and the adjusted detection position signal; and
a drive unit moving the lens based on the control signal,
the method comprising:
a first step of moving the lens to a first lens position to focus on the object located at a first position of a first focus distance;
a second step of moving the lens to a second lens position to focus on the object located at a second position for a second focus distance; and
a third step of rewriting the adjustment signal of the adjustment unit to limit a moving range of the lens based on the first focus distance and the second focus distance,
wherein the adjustment signal stored in the storage unit beforehand adjusts the detection position signal such that the lens moves from one end of a movable range of the lens to another end in the camera module.

10. A lens position control device, comprising:
a position sensor configured to detect positions of a lens, and to output a detection position signal;
a storage unit configured to store relationships of the lens positions and position code values, to be capable of rewriting the position code values;
a target position signal generation unit configured to output a target position signal based on the position code values and a target position code value representing a target position of the lens,
a control unit configured to generate a control signal to move the positions of the lens based on the target position signal and the detection position signal, and
a position code setting unit configured to rewrite the position code values stored in the storage unit so as to adjust a moving distance of the lens per at least one of the position code values.

11. The lens position control device according to claim 10 , wherein the position code values convert the target position code value into the target position signal such that the lens moves between a first position of a proximate focus distance and a second position of an infinite focus distance.

1

Assignees

• Asahi Kasei Microdevices Corp

Inventors

• Kasamatsu Arata
• Isogai Kazuomi

Classifications

• H04N23/673 Primary

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

• H04N23/57

  Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices · CPC title

• H04N5/23212 Primary

  Electricity · mapped topic

• H04N5/2257

  Electricity · mapped topic

• G02B7/08

  adapted to co-operate with a remote control mechanism · CPC title