US 6,636,700 B2 · Flash device, lens-fitted photo film unit, camera, light measuring device, and method of producing lens-fitted photo film unit

Abstract

A lens-fitted photo film unit is pre-loaded with photo film, and is a flash built-in type. A booster circuit boosts power source voltage to obtain high voltage. A main capacitor stores charge at the high voltage. A flash discharge tube is connected with the main capacitor, and emits flash light by discharge at the high voltage. A trigger circuit triggers the discharge of the flash discharge tube in response to an exposing operation. A main circuit board has the booster circuit and the trigger circuit mounted thereon. A subsidiary circuit board is connected with the main circuit board, and has a flash quenching circuit mounted thereon. The flash quenching circuit operates in an auxiliary manner, and automatically adjusts the amount of the flash light.

Claims27

Dependent claims

A flash device for emitting flash light toward a photographic object, comprising:

a main circuit board, having a main circuit element mounted thereon for emission of said flash light;
and
a subsidiary circuit board, having a subsidiary circuit element mounted thereon for adjusting an amount of said flash light being emitted;
wherein the main circuit element comprises:
a booster circuit for boosting a power source voltage to a high voltage;
and
a main capacitor, connected with said booster circuit, for being charged at said high voltage;
wherein said main capacitor includes a pair of capacitor terminal pins by which said main and subsidiary circuit boards are connected with one another.

5 more elements

A producing method of producing a lens-fitted photo film unit, said lens-fitted photo film unit including:

a main body, having a cassette holder chamber and a photo film chamber, said cassette holder chamber being loaded with a cassette, said photo film chamber being loaded with photo film drawn from said cassette in a roll form;
front and rear covers for covering respectively a front and a rear of said main body;
an externally operable charger button disposed in said front cover;
a photometric window formed in said front cover;
a flash window formed in said front cover;
a shutter blade, incorporated in said main body, for providing said photo film with an exposure;
and
a flash device, secured to said main body, and including:
(A) a charger power switch, disposed behind said charger button, for being turned on by operation of said charger button;
(B) a booster circuit for boosting power source voltage to obtain high voltage in turning on of said charger power switch;
(C) a main capacitor, connected with said booster circuit, for being charged at said high voltage;
(D) a flash discharge tube for emitting flash light upon a flow of a current of discharging said main capacitor;
(E) a flash emitter for containing said flash discharge tube;
(F) a sync switch for being turned on in synchronism with actuation of said shutter blade;
(G) a trigger circuit for triggering said flash discharge tube, to discharge said main capacitor;
(H) a main circuit board having said booster circuit and said trigger circuit mounted thereon;
(I) a photometric element, disposed behind said photometric window, for measuring reflected light from a photographic field illuminated by said flash light, and for outputting a photometric signal;
(J) a flash quenching circuit for obtaining a light amount by integration of said photometric signal, and for discontinuing operation of said flash discharge tube upon a reach of said light amount at a predetermined level;
(K) a subsidiary circuit board, connected with said main circuit board, having said photometric element and said flash quenching circuit mounted thereon;
said producing method comprising steps of:
securing said flash device to said main body to dispose said sync switch in a path of moving said shutter blade;
securing said front cover to said main body to dispose said charger button in front of said charger power switch, and dispose said flash window in front of said flash emitter;
after securing said front cover, inserting said cassette into said cassette holder chamber and said photo film into said photo film chamber;
after inserting said photo film, securing said rear cover to said main body;
said method further comprising the steps of:
attaching a middle of a pair of terminal pins of said main capacitor to said subsidiary circuit board by insertion through holes or grooves in said subsidiary circuit board and by soldering;
and
attaching an end of said terminal pins to said main circuit board by soldering, to combine said main and subsidiary circuit boards with one another by said terminal pins.

25 more elements

A producing method of producing a lens-fitted photo film unit, said lens-fitted photo film unit including:

a main body, having a cassette holder chamber and a photo film chamber, said cassette holder chamber being loaded with a cassette, said photo film chamber being loaded with photo film drawn from said cassette in a roll form;
front and rear covers for covering respectively a front and a rear of said main body;
an externally operable charger button disposed in said front cover;
a photometric window formed in said front cover;
a flash window formed in said front cover;
a shutter blade, incorporated in said main body, for providing said photo film with an exposure;
and
a flash device, secured to said main body, and including:
(A) a charger power switch, disposed behind said charger button, for being turned on by operation of said charger button;
(B) a booster circuit for boosting power source voltage to obtain high voltage in turning on of said charger power switch;
(C) a main capacitor, connected with said booster circuit, for being charged at said high voltage;
(D) a flash discharge tube for emitting flash light upon a flow of a current of discharging said main capacitor;
(E) a flash emitter for containing said flash discharge tube;
(F) a sync switch for being turned on in synchronism with actuation of said shutter blade;
(G) a trigger circuit for triggering said flash discharge tube, to discharge said main capacitor;
(H) a main circuit board having said booster circuit and said trigger circuit mounted thereon;
(I) a photometric element, disposed behind said photometric window, for measuring reflected light from a photographic field illuminated by said flash light, and for outputting a photometric signal;
(J) a flash quenching circuit for obtaining a light amount by integration of said photometric signal, and for discontinuing operation of said flash discharge tube upon a reach of said light amount at a predetermined level;
(K) a subsidiary circuit board, connected with said main circuit board, having said photometric element and said flash quenching circuit mounted thereon;
said producing method comprising steps of:
securing said flash device to said main body to dispose said sync switch in a path of moving said shutter blade;
securing said front cover to said main body to dispose said charger button in front of said charger power switch, and dispose said flash window in front of said flash emitter;
after securing said front cover, inserting said cassette into said cassette holder chamber and said photo film into said photo film chamber;
after inserting said photo film, securing said rear cover to said main body;
the method comprising the further steps of:
connecting said subsidiary circuit board with said main capacitor, to constitute a main capacitor unit together therewith;
and
connecting said main capacitor unit with said main circuit board, to constitute said flash device together therewith.

25 more elements

A producing method of producing a lens-fitted photo film unit, said lens-fitted photo film unit including:

a main body, having a cassette holder chamber and a photo film chamber, said cassette holder chamber being loaded with a cassette, said photo film chamber being loaded with photo film drawn from said cassette in a roll form;
front and rear covers for covering respectively a front and a rear of said main body;
an externally operable charger button disposed in said front cover;
a photometric window formed in said front cover;
a flash window formed in said front cover;
a shutter blade, incorporated in said main body, for providing said photo film with an exposure;
and
a flash device, secured to said main body, and including:
(A) a charger power switch, disposed behind said charger button, for being turned on by operation of said charger button;
(B) a booster circuit for boosting power source voltage to obtain high voltage in turning on of said charger power switch;
(C) a main capacitor, connected with said booster circuit, for being charged at said high voltage;
(D) a flash discharge tube for emitting flash light upon a flow of a current of discharging said main capacitor;
(E) a sync switch for being turned on in synchronism with actuation of said shutter blade;
(F) a trigger circuit for triggering said flash discharge tube, to discharge said main capacitor;
(G) a main circuit board having said booster circuit and said trigger circuit mounted thereon;
(H) a discharge tube case, secured to said main circuit board, for containing said flash discharge tube;
(I) a photometric element for measuring reflected light from a photographic field illuminated by said flash light, and for outputting a photometric signal;
(J) a flash quenching circuit for obtaining a light amount by integration of said photometric signal, and for discontinuing operation of said flash discharge tube upon a reach of said light amount at a predetermined level;
and
(K) a subsidiary circuit board, secured to said discharge tube case, and having said photometric element, said flash quenching circuit and said main capacitor mounted thereon;
said producing method comprising steps of:
securing said flash device to said main body;
securing said front cover to said main body to cover said flash device;
inserting said cassette with said photo film into said main body;
and
securing said rear cover to said main body.

23 more elements

Dependencies are inferred from the claim text.

Flash device, lens-fitted photo film unit, camera, light measuring device, and method of producing lens-fitted photo film unit

Life of this patent

Flash device, lens-fitted photo film unit, camera, light measuring device, and method of producing lens-fitted photo film unit

Life of this patent

Abstract

Claims27