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Patent Searching and Data


Title:
LIGHTING DEVICE FOR PHOTOGRAPHY
Document Type and Number:
Japanese Patent JP2002258363
Kind Code:
A
Abstract:

To improve the use efficiency of a power source by simple constitution by supplying a high voltage by using a low-voltage power source and making a light emitting diode which has a high forward voltage emit sufficient light for photographic lighting.

Before a shutter is released, the source voltage of a DC power source BP1 is boosted by a boosting circuit DD1 with a boosting control switch CSW1 ON and a main capacitor C1 is charged through a 1st diode D1. While the shutter is driven, the boosting control means CSW1 is turned off to inhibit the boosting circuit DD1 from operating and a shutter switch SSW1 is turned on to turn off a 2nd transistor Q2 and turn transistor Q1 and Q3 on, thereby supplying the voltage obtained by adding the charging voltage of the main capacitor to the voltage of the DC power source BP1 to light emitting diodes for lighting LW1, LB1, LG1, and LR1.


Inventors:
IGUCHI SUSUMU
Application Number:
JP2001060965A
Publication Date:
September 11, 2002
Filing Date:
March 05, 2001
Export Citation:
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Assignee:
RICOH KK
International Classes:
G03B15/03; G03B15/05; H02J1/00; H05B41/32; (IPC1-7): G03B15/05; G03B15/03; H02J1/00; H05B41/32
Attorney, Agent or Firm:
Shuji Sanada