Title:
オートフォーカス装置
Document Type and Number:
Japanese Patent JP3547777
Kind Code:
B2
Abstract:
PURPOSE:To quickly and surely execute focusing, even when a movable range of a focus lens is large. CONSTITUTION:A signal obtained from a CCD sensor 4 is allowed to pass through a first band pass filter 8 for allowing it to pass through extending from a low band component to a high band component, and a second band pass filter 9 for allowing it to pass through the band parts higher than the above-mentioned filter, a first and a second evaluation values f(x), g(x) are generated by a first and a second evaluation value generating parts 10, 11 from outputs of each band pass filter 8, 9, and a ratio s(x)=f(x)/g(x) of these evaluation values is differentiated by a differential arithmetic part 12a, by which in the case the differential value is plus or zero, it is decided not to be in the vicinity of a focused position and a focus control part 12b operates a focus driver 13 at high speed, and in the case its value is minus, it is decided to be in the vicinity of the focused position and its driver is operated at a low speed.
Inventors:
Shigeo Fujishi
Toshihiko Kubo
Toshihiko Kubo
Application Number:
JP29026893A
Publication Date:
July 28, 2004
Filing Date:
November 19, 1993
Export Citation:
Assignee:
Fuji Photo Film Co., Ltd.
International Classes:
H04N5/232; (IPC1-7): H04N5/232
Domestic Patent References:
| JP5145827A | ||||
| JP368280A | ||||
| JP263275A | ||||
| JP2280579A | ||||
| JP2268572A |
Attorney, Agent or Firm:
Toshiro Mitsuishi
Tadahiro Mitsuishi
Yasuyuki Tanaka
Tadahiro Mitsuishi
Yasuyuki Tanaka