US3950765A — Exposure control devices for photographic cameras

Claim 1

Independent Claim 148 words

An exposure control device for a photographic camera having an objective lens and an adjustable diaphragm, comprising: a light measuring circuit for measuring the scene light transmitted through said objective lens and said diaphragm and for generating a measured light output commensurate with the brightness of said scene light; a first circuit for generating a first output signal to control shutter speed commensurate with said measured light output; means for manually selecting shutter speed; a second circuit for generating a second output signal commensurate with the shutter speed selected by said manual shutter speed selecting means; a timing circuit for controlling the shutter speed; means for selectively connecting said first and second output signals to said timing circuit; detecting means for detecting the difference between said first and second output signals; and means for controlling the diaphragm aperture in response to the difference detected by said detecting means.

Claim 2

Dependent Claim 148 words

An exposure control device for a photographic camera having an objective lens and an adjustable diaphragm, comprising: a light measuring circuit for measuring the scene light transmitted through said objective lens and said diaphragm and for generating a measured light output commensurate with the brightness of said scene light; a first circuit for generating a first output signal to control shutter speed commensurate with said measured light output; means for manually selecting shutter speed; a second circuit for generating a second output signal commensurate with the shutter speed selected by said manual shutter speed selecting means; a timing circuit for controlling the shutter speed; means for selectively connecting said first and second output signals to said timing circuit; detecting means for detecting the difference between said first and second output signals; and means for controlling the diaphragm aperture in response to the difference detected by said detecting means.

Claim 3

Dependent Claim 32 words

An exposure control device as in claim 1, further comprising: means for triggering said timing circuit after operation of said means for controlling the diaphragm aperture in association with the release operation.

Claim 4

Dependent Claim 40 words

An exposure control device as in claim 1, wherein said means for manually selecting shutter speed includes an automatic exposure mode position, whereby selection of said automatic exposure mode causes said second output signal to be at a reference potential.

Claim 5

Dependent Claim 78 words

An exposure control device as in claim 1, further comprising: a diaphragm operating member for stopping-down the diaphragm from its fully open position; an arresting member for arresting said diaphragm operating member to maintain the diaphragm in the fully open position; and means for releasing said diaphragm operating member from arrest by said arresting member after said first and second circuits have operated in association with the release operation to generate said first and second output signals, respectively.

Claim 6

Dependent Claim 42 words

An exposure control device as in claim 4, wherein said first circuit includes means for storing said first output signal prior to the release of said diaphragm operating member from its arrested condition and the operation of said means for selectively connecting.

Claim 7

Dependent Claim 37 words

An exposure control device as in claim 4, further comprising: manual diaphragm aperture adjusting means for locking the diaphragm in a set position after said diaphragm operating member has been released from arrest by said arresting member.

Claim 8

Dependent Claim 56 words

An exposure control device as in claim 4, wherein said detecting means includes a meter for detecting the difference between said first and second output signals, said diaphragm aperture controlling means locks the diaphragm after the release of said arresting member from its arrested condition commensurate with the deflected angle of a pointer of said meter.

Claim 9

Dependent Claim 66 words

An exposure control device as in claim 4, wherein said detecting means includes a differential amplifier circuit, said first and second output signals are input to said differential amplifier circuit, and wherein with said differential amplifier circuit detecting that said first and second output signals are substantially equal, said diaphragm operating member is stopped by locking said diaphragm in position to thereby control the diaphragm aperture.

Claim 10

Dependent Claim 80 words

An exposure control device as in claim 6, further comprising means for storing said first output signal and wherein said manual diaphragm adjusting means is adjusted to a diaphragm aperture for photographing, said means for selectively connecting connects said means for storage to said timing circuit, said means for manually selecting the shutter speed is set to automatic exposure control, thereby controlling the shutter speed with the diaphragm aperture to be adjusted by means of said manual diaphragm adjusting means.

Claim 11

Dependent Claim 85 words

An exposure control device as in claim 6, wherein said means for manually selecting shutter speed selects a shutter speed for photographing, said manual diaphragm adjusting means is adjusted to the minimum diaphragm aperture, said means for selectively connecting connects said second signal circuit to said timing circuit, and said diaphragm aperture controlling means controls the diaphragm aperture for the selected shutter speed commensurate with the brightness of the scene light, and said timing circuit is operated at said selected shutter speed for exposure control.

Claim 12

Dependent Claim 90 words

An exposure control device as in claim 1, further comprising means for generating a constant voltage, a third circuit for generating a second output signal representative of the sum of said constant voltage and at least a portion of said first output signal, and switch means for alternatively connecting said second circuit or said third circuit to said detecting means, whereby when said third circuit is connected to said detecting means said means for controlling controls the diaphragm aperture in response to the difference between said first and third signals.

Claim 13

Dependent Claim 81 words

An exposure control device as in claim 11 further comprising a diaphragm operating member for stopping-down the diaphragm from its fully open position; an arresting member for arresting said diaphragm operating member to maintain the diaphragm in the fully open position; means for releasing said diaphragm operating member from said arresting member; means for storing said first output signal before the stopping-down of said diaphragm is commenced; and means for generating a voltage commensurate with a portion of the stored signal.

Claim 14

Dependent Claim 70 words

An exposure control device as in claim 12 further comprising a variable resistor common to said second and third circuits and including a tap at which said second and third output signals are generated, said switch means being disposed between said variable resistor and said means for generating a voltage commensurate with a portion of the stored signal, whereby said constant voltage can be varied by adjusting the variable resistor.

Claim 15

Dependent Claim 56 words

An exposure control device as in claim 13 wherein said detecting means includes a meter for detecting the difference between said first and second output signals, said diaphragm aperture controlling means locks the diaphragm after the release of said arresting member from its arrested condition commensurate with the deflected angle of a pointer of said meter.

Claim 16

Dependent Claim 65 words

An exposure control device as in claim 13, wherein said detecting means includes a differential amplifier circuit, said first and second output signals are input to said differential amplifier circuit, and wherein with said differential amplifier circuit detecting that said first and second signals are substantially equal, said diaphragm operating member is stopped by locking said diaphragm in position to thereby control the diaphragm aperture.

Claim 17

Dependent Claim 197 words

An exposure control device for a photographic camera having an objective lens and an adjustable diaphragm, comprising: a light measuring circuit for measuring scene light transmitted through said objective lens and said diaphragm to generate a measured light output commensurate with the brightness of said scene light; a first circuit for generating a first output signal commensurate with said measured light output; a second circuit for generating a constant output signal; means for storing said first output signal prior to the release of the diaphragm operating member from its arrested condition in response to releasing operation; converting means for producing a second output signal by adding a portion of the signal in said storage means to said constant output signal; means for detecting the difference between said first output signal and said second output signal; a diaphragm aperture control member for controlling the diaphragm aperture by locking said diaphragm operating member according to the difference detected by said means for detecting; a timing circuit for controlling the shutter speed; means applying said second output signal to said timing circuit; and means for triggering said timing circuit after said diaghragm aperture control member has controlled the diaphragm aperture.

Claim 18

Dependent Claim 197 words

An exposure control device for a photographic camera having an objective lens and an adjustable diaphragm, comprising: a light measuring circuit for measuring scene light transmitted through said objective lens and said diaphragm to generate a measured light output commensurate with the brightness of said scene light; a first circuit for generating a first output signal commensurate with said measured light output; a second circuit for generating a constant output signal; means for storing said first output signal prior to the release of the diaphragm operating member from its arrested condition in response to releasing operation; converting means for producing a second output signal by adding a portion of the signal in said storage means to said constant output signal; means for detecting the difference between said first output signal and said second output signal; a diaphragm aperture control member for controlling the diaphragm aperture by locking said diaphragm operating member according to the difference detected by said means for detecting; a timing circuit for controlling the shutter speed; means applying said second output signal to said timing circuit; and means for triggering said timing circuit after said diaghragm aperture control member has controlled the diaphragm aperture.

Claim 19

Dependent Claim 27 words

An exposure control device as in claim 16, wherein said means for applying selectively connects said converting means and said means for storing to said timing circuit.

Claim 20

Dependent Claim 28 words

An exposure control device as in claim 16, wherein said converting means includes means for manually varying said portion of the signal stored in said means for storing.

Claim 21

Dependent Claim 20 words

An exposure control device as in claim 16, wherein said converting means includes means for converting said constant output signal.

Claim 22

Dependent Claim 38 words

An exposure control device as in claim 19, wherein said means for applying selectively connects said converting means, said means for converting said constant output signal, said means for storing and said second circuit to said timing circuit.

Claim 23

Dependent Claim 59 words

An exposure control device as in claim 16, wherein an exposure control is effected by a pre-programmed relationship between the diaphragm aperture and shutter speed by triggering said timing circuit after said means for detecting has controlled the diaphragm aperture by said diaphragm aperture control member with said means for applying connecting said converting means to said timing circuit.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-04-13	1979-10-13	1980-04-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-04-13	1983-10-13	1984-04-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-04-13	1987-10-13	1988-04-13	$7700.00	Window Closed / Lapsed

Exposure control devices for photographic cameras

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