Patent ID: 6091898
Filing Date: 2000-07-18
Classification: G03B

Abstract:
A lens-fitted photo film unit, including a photo film housing, a photo film roll chamber formed in said photo film housing and pre-loaded with photo film in a roll form, and a cassette holder chamber, formed in said photo film housing, for incorporating a photo film cassette, to wind said photo film therein after being exposed, said photo film housing incorporating a flash-emission main capacitor, a flash discharge tube and a flash circuit, said main capacitor storing charge by a charging operation, said flash discharge tube emitting flash light by a discharging operation of said charge, and said flash circuit controlling said main capacitor and said flash discharge tube for effecting said charging operation and said discharging operation, said lens-fitted photo film unit comprising:a memory IC;a write control IC, incorporated in said photo film housing, for writing information to said memory IC, and for inhibiting said flash circuit from effecting said charging operation at least while said information is written; a battery for supplying said flash circuit, said write control IC, and said memory IC with power;a shutter mechanism, incorporated in said photo film housing, for taking an exposure on said photo film; andan exposure detector circuit for detecting operation of said shutter mechanism, to generate an exposure detection signal, wherein said write control IC starts writing said information in response to said exposure detection signal;wherein said flash circuit includes:a trigger capacitor charged by said charging operation;a trigger switch for discharging said trigger capacitor, said trigger switch being turned on by an opening actuation of said shutter mechanism, to cause said exposure detector circuit to generate said exposure detection signal; anda trigger transformer for generating a trigger voltage upon discharge of said trigger capacitor, to start said discharging operation of said main capacitor.