AUTOMATIC FOCUSING APPARATUS - CITIZEN WATCH CO LTD

Title:

AUTOMATIC FOCUSING APPARATUS

Document Type and Number:

WIPO Patent Application WO/2006/054562

Kind Code:

A1

Abstract:

A liquid crystal lens driver is used to apply a predetermined voltage to a liquid crystal lens. An image signal is generated based on an optical image having passed through the liquid crystal lens operating in transient response because of the application of the predetermined voltage. The generated image signal is sampled at predetermined intervals to extract a plurality of autofocus signals. A comparison is made among the levels of the extracted autofocus signals to determine the maximum value of the autofocus signals. In this way, the liquid crystal lens and the transient response operation thereof are used to detect a focus point with sufficient rapidity.

Inventors:

SUZUKI KAZUO (JP)
KATO YUICHI (JP)
KAWADA TAKAHIRO (JP)
KAGEYAMA YASUHIRO (JP)
ANDO TOMOHIRO (JP)

Application Number:

PCT/JP2005/020973

Publication Date:

May 26, 2006

Filing Date:

November 15, 2005

Export Citation:

Click for automatic bibliography generation Help

Assignee:

CITIZEN WATCH CO LTD (JP)
SUZUKI KAZUO (JP)
KATO YUICHI (JP)
KAWADA TAKAHIRO (JP)
KAGEYAMA YASUHIRO (JP)
ANDO TOMOHIRO (JP)

International Classes:

G02B7/28; G02B7/36; G02F1/13; G03B13/36; H04N5/232

Foreign References:

JPS61140908A	1986-06-28
JPH0553089A	1993-03-05
JP2001154085A	2001-06-08
JPS6236632A	1987-02-17
JPS61156228A	1986-07-15
JP2002122784A	2002-04-26
JP2004191893A	2004-07-08
JP2002228816A	2002-08-14
JP2008044248A	2008-02-28
JP2742741B2	1998-04-22
JPS6415188A	1989-01-19
JP2008011068A	2008-01-17

Other References: