US3728946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching apparatus for exposure control devices
Assignee: Minolta Co Ltd
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Filing: 1971-07-06
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Granted: 1973-04-24
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Expires: 1991-07-06
Abstract
Abstract Switching mechanism in an exposure control device for a photoconductive camera reduces unnecessary battery consumption by disconnecting the power source from a light measuring circuit and a mechanism for actuating shutter closing during those times when either the output of the light measuring circuit and/or the actuation of the shutter are not required. Manually operative individual switches respectively interconnect the light measuring circuit and the shutter actuation mechanism with the power source. A button switch movable between first and second positions engages with a locking member to prevent actuation of the shutter release button to prevent interconnection of the shutter actuating mechanism with the power source when an exposure time setting member is set to an automatic exposure position and the button switch is in the first position for opening the switch interconnecting the light measuring circuit with the battery source. Rotation of the exposure time setting member to any one of a number of positions rotates the locking member enabling the release button to be depressed and the interconnection of the shutter actuating mechanism with the battery source.
Inventors
- 👤 Y Kuramoto
- 👤 K Tsujimoto
- 👤 K Yata
- 👤 M Sahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:50
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/083
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
190 words
An exposure control device for a photographic camera of the type having a photoconductive member for receiving scene light through an objective lens of the camera, comprising: an electric power source; a light measuring circuit for generating an output signal as a function of the light intensity incident on said photoconductive member; a first switch connected between said electric power source and said light measuring circuit; means for storing said output signal; a second switch selectively connecting said means for storing to said light measuring circuit for storing said output signal; means for actuating shutter closing; an electric timing means responsive to said stored output signal for controlling said means for actuating and timing the shutter closing in accordance with said light intensity on said photoconductive member; A third switch connected between said electric Power source and said means for actuating; first means for closing said first switch to connect said light measuring circuit to said electric power source; and second means for closing said third switch to connect said means for actuating to said electric power source, said first and second means being manually independently operable of each other.
Claim 2
Dependent Claim
190 words
An exposure control device for a photographic camera of the type having a photoconductive member for receiving scene light through an objective lens of the camera, comprising: an electric power source; a light measuring circuit for generating an output signal as a function of the light intensity incident on said photoconductive member; a first switch connected between said electric power source and said light measuring circuit; means for storing said output signal; a second switch selectively connecting said means for storing to said light measuring circuit for storing said output signal; means for actuating shutter closing; an electric timing means responsive to said stored output signal for controlling said means for actuating and timing the shutter closing in accordance with said light intensity on said photoconductive member; A third switch connected between said electric Power source and said means for actuating; first means for closing said first switch to connect said light measuring circuit to said electric power source; and second means for closing said third switch to connect said means for actuating to said electric power source, said first and second means being manually independently operable of each other.
Claim 3
Dependent Claim
100 words
An exposure control device as in claim 1, wherein said light measuring circuit includes a constant current generating circuit connectable to the electric power source through said first switch, and said photoconductive member comprises a first photoconductive element connected in series with a fixed resistance and a second photoconductive element connected in parallel with said first photoconductive element and said fixed resistance, and said first and second photoconductive elements are connected to said constant current generating circuit for generating output voltage proportional to the logarithmic value of the intensity of light received on both said first and second photoconductive elements.
Claim 4
Dependent Claim
137 words
An exposure control device as set forth in claim 1, wherein said first means is movable between a first position for opening said first switch and a second position for closing said first switch, and said first means is biased to said first position; said second means is movable between a first position for opening said third switch and a second position for initiating exposure by closing said third switch, and said second means is biased to said first position; and said exposure control device further comprising: an interlocking member engageable with said first means and said second means, and said interlocking member is biased to maintain said engagement for preventing the movement of said second means from said first position thereof to said second position thereof when said first means is in said first position thereof.
Claim 5
Dependent Claim
26 words
An exposure control device as in claim 1, wherein said electric timing circuit includes a switching circuit interconnecting said means for actuating and said third switch.
Claim 6
Dependent Claim
40 words
An exposure control device as in claim 1, further comprising, an interlocking member for preventing said second means from closing said third switch when said first switch is opened to disconnect said light measuring circuit from said electric power source.
Claim 7
Dependent Claim
62 words
An exposure control device as in claim 5, further comprising, an exposure time setting member movable to an automatic exposure position and a selected one of a number of manual exposure setting positions and interconnected with said interlocking member for preventing said second means from closing said third switch when said exposure time setting member is set to said automatic exposure position.
Claim 8
Dependent Claim
34 words
An exposure control device as in claim 6, wherein said electric timing means includes biasing means for adjusting the exposure time, and the movement of said exposure time setting member controls said biasing means.
Claim 9
Dependent Claim
143 words
An exposure control device as in claim 7, wherein said exposure time setting member includes a cam member having a notched portion, said biasing means comprises a contact slidable on a variable resistance, and a member for actuating a fourth switch for selectively connecting said electric timing means to said means for storing and said variable resistance, whereby when said exposure time setting member is positioned at said manual exposure position, said fourth switch connects said electric timing means to said variable resistance and said cam member retains said interlocking member to prevent said second means from closing said third switch, and whereby when said exposure time setting member is positioned at said automatic exposure position, said fourth switch connects said electric timing means to said means for storing and said notched portion releases said interlocking member from engagement with said second means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |