Optical member driving apparatus and projection type image display apparatus

Patent metadata

Field	Value
Publication number	US-2016306269-A1
Application number	US-201615192751-A
Country	US
Kind code	A1
Filing date	Jun 24, 2016
Priority date	Dec 27, 2013
Publication date	Oct 20, 2016
Grant date	—

Abstract

An optical member driving apparatus includes an optical member for changing an optical path, a plurality of actuators each having a movable member which is controlled to move in one direction, a plurality of connecting members which connect edge portions of the optical member positioned on two axes orthogonal to each other and the movable members of the plurality of actuators, respectively, a position detector for detecting a moving amount of the movable member of each actuator and outputting a detection signal indicating the moving amount, and a controller for controlling movement of the movable member of each actuator based on the detection signal from the position detector so as to keep an intersection point of the two axes at constant position.

First claim

1 . An optical member driving apparatus comprising:
an optical member for changing an optical path; a plurality of actuators each having a movable member which is controlled to move in one direction; a plurality of connecting members which connect edge portions of the optical member positioned on two axes orthogonal to each other and the movable members of the plurality of actuators, respectively; a position detector for detecting a moving amount of the movable member of each actuator and outputting a detection signal indicating the moving amount; and a controller for controlling movement of the movable member of each actuator based on the detection signal from the position detector so as to keep an intersection point of the two axes at constant position.

2 . The optical member driving apparatus according to claim 1 , wherein
the plurality of actuators include first to fourth actuators; the first and second actuators are mounted on one of the two axes and on the edge portions of the optical member, facing each other; and the third and fourth actuators are mounted on the other of the two axes and on the edge portions of said optical member, facing each other.

3 . The optical member driving apparatus according to claim 2 , wherein, in initial adjustment of the actuators, the controller controls positions of the movable members of at least three actuators among the first to fourth actuators to the corresponding reference positions, and then set the position of the movable member of one actuator among the first to fourth actuators at which driving power of the one actuator is minimum, as a setting value of the reference position of the movable member for the one actuator.

4 . The optical member driving apparatus according to claim 2 , wherein, in initial adjustment of the actuators, the controller
controls the movable members of the first and second actuators to move in opposite direction to each other by a predetermined amount, determines driving power of the third and fourth actuators while adjusting a gain of the detection signal from the position detector, and detects a value of the gain which minimizes a difference between a total of driving power of the third and fourth actuators before the first and second actuators are moved in the opposite direction to each other by the predetermined amount and a total of driving power of the third and fourth actuators after the first and second actuators are moved in the opposite direction to each other by the predetermined amount, and in normal operation, the controller sets the detected gain to a gain of the detection signal from the position detector.

5 . The optical member driving apparatus according to claim 4 , wherein, in the initial adjustment of the actuators, the controller further
controls the movable members of the third and fourth actuators in opposite direction to each other by a predetermined amount, determines driving power of the first and second actuators while adjusting a gain of the detection signal from the position detector, and detects a value of the gain which minimizes a difference between a total of driving power of the first and second actuators before the third and fourth actuators are moved in the opposite direction to each other by the predetermined amount and a total of driving power of the first and second actuators after the third and fourth actuators are moved in the opposite direction to each other by the predetermined amount, and in the normal operation, the controller sets the detected gain to a gain of detection signal from the position detector.

6 . The optical member driving apparatus according to claim 1 , wherein the actuator is a voice coil motor.

7 . The optical member driving apparatus according to claim 1 , wherein the connecting member is an elastic member.

8 . The optical member driving apparatus according to claim 1 , wherein the controller includes a single microcomputer.

9 . The optical member driving apparatus according to claim 1 , wherein the optical member is a circular parallel plate glass.

10 . The optical member driving apparatus according to claim 1 , wherein the optical member is a square parallel plate glass.

11 . A projection type image display apparatus comprising:
a light source; an optical modulation device for modulating light from the light source with a video signal; a projection optical system for magnifying and projecting the light modulated by the optical modulation device; and the optical member driving apparatus according to claim 1 which is arranged between the optical modulation device and the projection optical system.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Gyoten Takaaki
• Kondo Nobuyuki
• Mashitani Ken

Classifications

• H04N9/3194

  including sensor feedback · CPC title

• G02B26/0875

  by means of one or more refracting elements · CPC title

• G03B21/142

  Adjusting of projection optics · CPC title

• G03B2205/0069

  using electromagnetic actuators, e.g. voice coils · CPC title

• H04N9/3188

  Scale or resolution adjustment (scaling in general G06T3/40; resolution modifying circuits for displays in general G09G5/391) · CPC title