Title:
AUTOMATIC FOCUSING DEVICE
Document Type and Number:
Japanese Patent JP3191885
Kind Code:
B2
Abstract:
PURPOSE: To provide a device which surely and stably performs automatic focusing operation even during zooming without generating slight out-of-focus stopping or hatching even when shutter speed is lowered by controlling the lens driving speed of a focus lens driving means corresponding to shutter speed information from a shutter speed control means.
CONSTITUTION: Shutter speed data selected at a shutter speed selecting means 24 are outputted to a shutter speed controller 25. Corresponding to the shutter speed data, the shutter speed controller 25 sets timing for the charge storage time of a CCD 6, outputs this timing to a CCD drive circuit 26 and sends it to a controller 12 and a video signal processing circuit 8 together with the shutter speed. The controller 12 controls a stepping motor 18 through a motor drive 15 based on the position information of a focus compensation lens 5 and a zoom lens 2 and a sharpness signal extracted from a video signal.
Inventors:
Taeko Tanaka
Application Number:
JP26817592A
Publication Date:
July 23, 2001
Filing Date:
September 10, 1992
Export Citation:
Assignee:
Canon Inc
International Classes:
G02B7/08; G02B7/28; H04N5/232; (IPC1-7): H04N5/232; G02B7/08; G02B7/28
Domestic Patent References:
| JP229172A | ||||
| JP2220573A | ||||
| JP5887863A | ||||
| JP431809A | ||||
| JP419702A | ||||
| JP1101071A | ||||
| JP319475A |
Attorney, Agent or Firm:
Toshihiko Watanabe