US3779141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling an electronic flash
Assignee: Minolta Co Ltd
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Filing: 1971-12-17
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Granted: 1973-12-18
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Expires: 1991-12-17
Abstract
Abstract An exchangeable lens barrel for use in a photographic camera is provided with a light sensitive element which, when the exchangeable lens barrel has been exactly fitted to the camera, receives the light which is reflected from the light sensitive film surface after it is transmitted through the objective lens and the iris aperture of the exchangeable lens barrel. A control system for an electronic flash tube in the camera or an electronic flash device fitted to the camera comprises a lighting control circuit and includes a timing circuit which controls the lighting of the electronic flash tube. The timing circuit is connected with the light sensitive element to generate a current which is integrated by the timing circuit, and the electronic flash tube is extinguished when the integrated voltage reaches a certain predetermined level, thereby the opening of the iris aperture in the exchangeable lens barrel is transmitted to the control circuit.
Inventors
- 👤 H Ueda
- 👤 K Tsujimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:52
CPC Classifications
G; G03; G03B; G03B15/00; G03B15/02; G03B15/03; G03B15/05; G03B7/00; G03B7/16; G03B9/00; G03B9/70; G03B2215/00; G03B2215/05
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
193 words
Apparatus for controlling an electronic flash comprising: a lens barrel exchangeably mounted on a camera body and having an objective lens and an iris diaphragm; a light receptive element mounted on said lens barrel at the periphery of said objective lens facing the light sensitive film surface with said lens barrel mounted on said camera body whereby said light receptive element receives the light transmitted through said objective lens and the iris aperture and reflected from said light sensitive surface; a power source; means for generating an electronic flash connected in series with said power source; a main capacitor connected with said power source across said means for generating an electronic flash for exciting said means for generating; a trigger circuit including a trigger capacitor and a synchronous shutter switch connected in series with said trigger capacitor; an integrating circuit including an integrating capacitor for integrating the current generated by said light receptive element in accordance with the light received thereon; and an electric timing means for controlling the excitation of said means for generating an electronic flash by extinguishing it when the integrated voltage of said integrating capacitor reaches a predetermined voltage.
Claim 2
Dependent Claim
193 words
Apparatus for controlling an electronic flash comprising: a lens barrel exchangeably mounted on a camera body and having an objective lens and an iris diaphragm; a light receptive element mounted on said lens barrel at the periphery of said objective lens facing the light sensitive film surface with said lens barrel mounted on said camera body whereby said light receptive element receives the light transmitted through said objective lens and the iris aperture and reflected from said light sensitive surface; a power source; means for generating an electronic flash connected in series with said power source; a main capacitor connected with said power source across said means for generating an electronic flash for exciting said means for generating; a trigger circuit including a trigger capacitor and a synchronous shutter switch connected in series with said trigger capacitor; an integrating circuit including an integrating capacitor for integrating the current generated by said light receptive element in accordance with the light received thereon; and an electric timing means for controlling the excitation of said means for generating an electronic flash by extinguishing it when the integrated voltage of said integrating capacitor reaches a predetermined voltage.
Claim 3
Dependent Claim
71 words
Apparatus for controlling an electronic flash as in claim 1, further comprising: a discharge tube having an impedance less than that of said means for generating an electronic flash and connected across said means for generating; a discharge circuit including a capacitor and switching means for triggering said discharge tube; and a switching circuit for enabling said switching means when the integrated voltage of said integrating capacitor reaches said predetermined voltage.
Claim 4
Dependent Claim
36 words
Apparatus for controlling an electronic flash as in claim 1, wherein said means for generating an electronic flash is an annular electronic flash tube mounted in the periphery of said objective lens to face an object.
Claim 5
Dependent Claim
83 words
Apparatus for controlling an electronic flash as in claim 1, further comprising: a condenser lens which is mounted at the periphery of said Objective lens in front of the light receiving surface of said light receptive element and at a position proximate to the optical axis of said objective lens and nearer thereto than said light receptive element for collectively directing a selected portion of the light reflected on the central portion of said light sensitive film surface towards said light receptive element.
Claim 6
Dependent Claim
64 words
Apparatus for controlling an electronic flash as in claim 4, further comprising: a shielding member including an opening therein and mounted at the periphery of said objective lens in front of the light receiving surface of said light receptive element for shielding only such light that is transmitted through said objective lens and said iris aperture and normally reflected on said light sensitive surface.
Claim 7
Dependent Claim
58 words
Apparatus for controlling an electronic flash as in claim 5, wherein said light receptive element includes a number of light sensitive elements and said shielding member includes a number of shielding elements mounted on said exchangeable lens barrel at the periphery of said objective lens and said iris aperture thereof symmetrically with respect to the optical axis thereof.
Claim 8
Dependent Claim
164 words
Apparatus for controlling an electronic flash as in claim 1, further comprising: lead lines respectively connected to both terminals of said light receptive element in said exchangeable lens barrel; a plug including terminals insulated from each other and individually connected with said lead lines; a case enclosing said means for generating an electronic flash; a connecting terminal formed on said case and mounting said plug; a movable pin mounted within said connecting terminal and movable to projected and retracted positions in accordance with said plug being inserted into and taken out of said connecting terminal; a change-over switch having a contact engaging said movable pin; two contacts engaging with said contact; said means for generating an electronic flash including a light sensitive element connected with one of said two contacts and connected with said integrating capacitor; and means connected with the other of said two contacts to connect said light sensitive element in said exchangeable lens barrel to said integrating capacitor in parallel therewith.
Claim 9
Dependent Claim
154 words
Apparatus for controlling an electronic flash as in claim 7, further comprising: a plug including a pin connected via a lead line with one of the terminals of said light sensitive element in said exchangeable lens barrel, and a housing insulated from said pin and connected via a lead line with the other of said terminals of said light sensitive element; a case including a connecting terminal and said case enclosing said means for generating an electronic flash, and including a conductive tube receiving said pin and having a terminal insulated from said conductive tube and connected with said plug housing; an insulative pin engageable with said pin within said conductive tube and slidably shifted to either a protruding or retracted position with respect to said conductive tube; and a change-over switch including a contact movable to come into contact with either one of said two contacts thereof by engagement with said insulative pin.
Claim 10
Dependent Claim
96 words
Photographic apparatus comprising: an objective lens barrel for exchangeable mounting on a photographic camera body adapted to receive a light sensitive film surface, said lens barrel comprising; an objective lens including an iris diaphragm, a light sensitive element mounted around the periphery of said objective lens and facing the light sensitive film surface for receiving the light transmitted through said objective lens and said iris aperture and reflected from said light sensitive film surface, an electronic flash tube controlled by a control circuit, and connecting means for connecting said light sensitive element to said control circuit.
Claim 11
Dependent Claim
96 words
Photographic apparatus comprising: an objective lens barrel for exchangeable mounting on a photographic camera body adapted to receive a light sensitive film surface, said lens barrel comprising; an objective lens including an iris diaphragm, a light sensitive element mounted around the periphery of said objective lens and facing the light sensitive film surface for receiving the light transmitted through said objective lens and said iris aperture and reflected from said light sensitive film surface, an electronic flash tube controlled by a control circuit, and connecting means for connecting said light sensitive element to said control circuit.
Claim 12
Dependent Claim
92 words
Photographic apparatus comprising: an objective Lens barrel for exchangeable mounting on a photographic camera body adapted to receive a light sensitive film surface, said lens barrel comprising; an objective lens including an iris diaphragm, a light sensitive element mounted at said objective lens and facing said light sensitive film surface for receiving the light transmitted through said objective lens and said iris diaphragm and reflected from said light sensitive surface, an electronic flash tube controlled by a control circuit, and connecting means for connecting said light sensitive element to said control circuit.
Claim 13
Dependent Claim
92 words
Photographic apparatus comprising: an objective Lens barrel for exchangeable mounting on a photographic camera body adapted to receive a light sensitive film surface, said lens barrel comprising; an objective lens including an iris diaphragm, a light sensitive element mounted at said objective lens and facing said light sensitive film surface for receiving the light transmitted through said objective lens and said iris diaphragm and reflected from said light sensitive surface, an electronic flash tube controlled by a control circuit, and connecting means for connecting said light sensitive element to said control circuit.
References Cited (Backward Citations)
US3180218A
Cited
US3353462A
Cited
US3474242A
Cited
US3568582A
Cited
US3541387A
Cited
US3601022A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |