US3742827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shutter control apparatus for photographic cameras
Assignee: Eastman Kodak Co
•
Filing: 1971-03-15
•
Granted: 1973-07-03
•
Expires: 1991-03-15
Abstract
Abstract In a camera having a light-integrating, timing circuit for determining the exposure interval in accordance with the level of scene illumination, a shutter mechanism for uncovering and covering the exposure aperture and means for disabling the covering of the exposure aperture by the shutter mechanism until the shutter mechanism has uncovered the exposure aperture. The timing circuit includes a photosensitive element having an electrical parameter which varies as a function of incident scene illumination and a capacitor or storage element, which is charged as a function of the electrical parameter for providing a signal to effect aperture covering by the shutter mechanism. Further, the timing circuit includes a test circuit operable in a first or measuring mode to be coupled to the photosensitive element for providing an indication of whether there is sufficient scene illumination for film exposure and for varying a signal upon the capacitor element during the test mode in order to reduce the exposure interval and to thereby compensate for any delay that the shutter mechanism may have in effecting aperture covering.
Inventors
- 👤 O Wisst
- 👤 K Haberle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:33
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/083; G03B9/00; G03B9/58
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
268 words
In a camera for exposing film to scene illumination through an exposure aperture, exposure control apparatus comprising: shutter means for uncovering and covering the exposure aperture, said shutter means having a delay period, after actuation, before effecting the covering of the exposure aperture; threshold switch means coupled to said shutter means for actuating said shutter means; a timing and measuring circuit having photosensitive means with an electrical parameter dependent upon incident scene illumination, capacitive means, indicator means, and switch means responsive to the uncovering of the exposure aperture to be disposed from a first position to a second position, said circuit being operable in a first mode wherein said switch means is disposed in said first position for permitting said circuit to energize said indicator means to provide an indication of whether there is sufficient illumination to effect proper film exposure and for disposing a first charge upon said capacitive means, said circuit being operable in a second mode wherein said switch means is disposed in said second position for coupling said photosenstive means to said capacitive means to thereby vary the signal stored upon said capacitive means as a function of scene illumination incident upon said photosensitive means, said capacitance means being coupled to said threshold switch means for activating said threshold switch means when said stored signal reaches said predetermined level; and second switch means for disabling said threshold switch means while said circuit means is operative in its first mode of operation, said second switch means being responsive to the uncovering of the exposure aperture by said shutter means for enabling said threshold switch means.
Claim 2
Dependent Claim
268 words
In a camera for exposing film to scene illumination through an exposure aperture, exposure control apparatus comprising: shutter means for uncovering and covering the exposure aperture, said shutter means having a delay period, after actuation, before effecting the covering of the exposure aperture; threshold switch means coupled to said shutter means for actuating said shutter means; a timing and measuring circuit having photosensitive means with an electrical parameter dependent upon incident scene illumination, capacitive means, indicator means, and switch means responsive to the uncovering of the exposure aperture to be disposed from a first position to a second position, said circuit being operable in a first mode wherein said switch means is disposed in said first position for permitting said circuit to energize said indicator means to provide an indication of whether there is sufficient illumination to effect proper film exposure and for disposing a first charge upon said capacitive means, said circuit being operable in a second mode wherein said switch means is disposed in said second position for coupling said photosenstive means to said capacitive means to thereby vary the signal stored upon said capacitive means as a function of scene illumination incident upon said photosensitive means, said capacitance means being coupled to said threshold switch means for activating said threshold switch means when said stored signal reaches said predetermined level; and second switch means for disabling said threshold switch means while said circuit means is operative in its first mode of operation, said second switch means being responsive to the uncovering of the exposure aperture by said shutter means for enabling said threshold switch means.
Claim 3
Dependent Claim
32 words
Apparatus as claimed in claim 1, including third switch means responsive to the uncovering of the exposure aperture by said shutter means, for applying an energizing potential to said threshold switch means.
Claim 4
Dependent Claim
79 words
Apparatus as claimed in claim 1, wherein said threshold switch means determines the threshold level with respect to a reference potential, said disabling means including a switch for applying to said threshold switch means a first reference signal of a relatively low level and a second reference signal of a relatively high level, said switch means applying the first reference signal to said threshold switch means in response to the opening of the exposure aperture by said shutter means.
Claim 5
Dependent Claim
45 words
Apparatus as claimed in claim 1, wherein said disabling means includes switch means operative from an opened position to a closed position for applying the signal derived from said capacitance means to said threshold switch means in response to the uncovering of the exposure aperture.
Claim 6
Dependent Claim
52 words
Apparatus as claimed in claim 1, wherein said shutter means includes an opening member movable from a first position covering the exposure aperture, to a second position uncovering the exposure aperture; and a closing member movable from a first position uncovering the exposure aperture to a second position covering the exposure aperture.
Claim 7
Dependent Claim
31 words
Apparatus as claimed in claim 5, wherein said disabling means is operative in response to the movement of said opening blade to its second position to enable said threshold switch means.
Claim 8
Dependent Claim
187 words
In combination with a camera for exposing film to scene illumination, exposure control apparatus comprising: energizable indicating means for indicating whether there is sufficient scene illumination for film exposure; actuatable shutter means operable for initiating and terminating film exposure, said shutter means having a delay, after actuatIon to terminate the exposure, before operating to terminate the exposure; a circuit coupled to said indicator and including photosensitive means exposed to receive incident scene illumination and means for storing an electrical signal, said circuit being operable in a first mode for energizing said indicating means and for prestoring an electrical signal upon said storing means in proportion to the intensity of the illumination incident onto said photosensitive means, said circuit being operable in a second mode for providing an actuating signal to actuate said shutter means to terminate film exposure, said actuating signal including said prestored signal for compensating for said delay in operation of said shutter means; and switch means, responsive to the initiation of film exposure, for coupling said circuit to said shutter means after initiation of said exposure to prevent the premature termination of film exposure.
Claim 9
Dependent Claim
187 words
In combination with a camera for exposing film to scene illumination, exposure control apparatus comprising: energizable indicating means for indicating whether there is sufficient scene illumination for film exposure; actuatable shutter means operable for initiating and terminating film exposure, said shutter means having a delay, after actuatIon to terminate the exposure, before operating to terminate the exposure; a circuit coupled to said indicator and including photosensitive means exposed to receive incident scene illumination and means for storing an electrical signal, said circuit being operable in a first mode for energizing said indicating means and for prestoring an electrical signal upon said storing means in proportion to the intensity of the illumination incident onto said photosensitive means, said circuit being operable in a second mode for providing an actuating signal to actuate said shutter means to terminate film exposure, said actuating signal including said prestored signal for compensating for said delay in operation of said shutter means; and switch means, responsive to the initiation of film exposure, for coupling said circuit to said shutter means after initiation of said exposure to prevent the premature termination of film exposure.
Claim 10
Dependent Claim
225 words
In combination with a camera for exposing film to scene illumination, exposure control apparatus comprising: means defining an exposure aperture; actuatable shutter means, operable for uncovering and covering said exposure aperture, said shutter means having a delay after actuation before operating to cover said exposure aperture; at least one energizable, indicator; timing and measuring circuit means coupled to said indicator and including a photosensitive element located to receive scene illumination and means for storing an electrical signal, said circuit being operative in a first mode for energizing said indicator when there is insufficient scene illumination to effect exposure and for providing a first electrical signal proportional to scene illumination intensity for storage upon said storing means, said circuit means being operative in a second mode for providing a second time varying electrical signal upon said storing means, said second electrical signal being combined with said first electrical signal for providing a threshold proportional to the intensity of scene illumination upon said photosensitive means; threshold switch means coupled to said shutter means and said timing circuit means for actuating said shutter means to close said exposure aperture when said combined first and second electrical signals reach said threshold; and disabling means for preventing said switch means from actuating said shutter to close said exposure aperture until after said shutter means effects uncovering of said exposure aperture.
Claim 11
Dependent Claim
225 words
In combination with a camera for exposing film to scene illumination, exposure control apparatus comprising: means defining an exposure aperture; actuatable shutter means, operable for uncovering and covering said exposure aperture, said shutter means having a delay after actuation before operating to cover said exposure aperture; at least one energizable, indicator; timing and measuring circuit means coupled to said indicator and including a photosensitive element located to receive scene illumination and means for storing an electrical signal, said circuit being operative in a first mode for energizing said indicator when there is insufficient scene illumination to effect exposure and for providing a first electrical signal proportional to scene illumination intensity for storage upon said storing means, said circuit means being operative in a second mode for providing a second time varying electrical signal upon said storing means, said second electrical signal being combined with said first electrical signal for providing a threshold proportional to the intensity of scene illumination upon said photosensitive means; threshold switch means coupled to said shutter means and said timing circuit means for actuating said shutter means to close said exposure aperture when said combined first and second electrical signals reach said threshold; and disabling means for preventing said switch means from actuating said shutter to close said exposure aperture until after said shutter means effects uncovering of said exposure aperture.
Claim 12
Dependent Claim
170 words
In combination with a camera for exposing film to scene illumination, exposure control apparatus comprising: energizable indicating means; actuatable shutter means operable for initiating and terminating film exposure, said shutter means having a delay, after actuation to terminate the exposure, before operating to terminate the exposure; and a timing and measuring circuit coupled to said indicating means and including photosensitive means exposed to receive incident scene illumination and means for storing an electrical signal, said circuit being operable in a measuring mode for testing the sufficiency of scene illumination for exposure and for energizing said indicating means when scene illumination is insufficient to expose the film and for storing an electrical signal upon said storing means in porportion to the intensity of scene illumination incident onto said photosensitive means, said circuit being operable in a second mode for providing an actuating signal to actuate said shutter means to terminate film exposure, said actuating signal including said stored electrical signal for compensating for said delay in operation of said shutter means.
Claim 13
Dependent Claim
170 words
In combination with a camera for exposing film to scene illumination, exposure control apparatus comprising: energizable indicating means; actuatable shutter means operable for initiating and terminating film exposure, said shutter means having a delay, after actuation to terminate the exposure, before operating to terminate the exposure; and a timing and measuring circuit coupled to said indicating means and including photosensitive means exposed to receive incident scene illumination and means for storing an electrical signal, said circuit being operable in a measuring mode for testing the sufficiency of scene illumination for exposure and for energizing said indicating means when scene illumination is insufficient to expose the film and for storing an electrical signal upon said storing means in porportion to the intensity of scene illumination incident onto said photosensitive means, said circuit being operable in a second mode for providing an actuating signal to actuate said shutter means to terminate film exposure, said actuating signal including said stored electrical signal for compensating for said delay in operation of said shutter 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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |