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Patent Searching and Data


Title:
FLASH DEVICE
Document Type and Number:
Japanese Patent JPS59201028
Kind Code:
A
Abstract:

PURPOSE: To execute exactly an automatic dimming by providing a control means for reducing a peak light quantity value at the time of emitting a flash light, in case an object to be photographed is in a short distance.

CONSTITUTION: A reflected light by an object to be photographed and a luminance signal of an external light component are outputted from a terminal A+B of a differential type CCD SPE. In case the object to be photographed is in a comparatively short distance, and a level of the reflected light or a luminance of the external light is high, a comparator CP11 outputs a signal at H level. Also, an AND gate AN10 outputs a signal at H level until a level of a non- inversion input terminal of a comparator CP13, and divided voltage by resistances R20, R21 and R22 of a capacitor C30 become equal, a transistor TR11 is turned on, and a boosting circuit DCC is operated. When a shutter button is pushed, a light emitting signal turns on a thyristor SR1 through a terminal M1, a flash light whose optical energy is comparatively small is emitted, and an automatic dimming is executed.


Inventors:
TSUNEKAWA TOKUICHI
SATOU YUUICHI
KAWABATA TAKASHI
MATSUMURA SUSUMU
Application Number:
JP7586383A
Publication Date:
November 14, 1984
Filing Date:
April 28, 1983
Export Citation:
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Assignee:
CANON KK
International Classes:
G03B15/05; H05B41/32; (IPC1-7): H05B41/32
Attorney, Agent or Firm:
Marushima Giichi