US4372657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for indicating photographic exposure conditions
Assignee: West Electric Co Ltd
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Filing: 1981-06-10
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Granted: 1983-02-08
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Expires: 2001-06-10
Abstract
Abstract In a camera, a device for indicating photographic exposure conditions in which an electrooptic element or window is incorporated in a finder system in such a way that when exposure conditions such as the brightness of an object, the conditions of a battery and the condition of an electronic flash device are unsatisfactory so that an erratic exposure will result, the electrooptic element or window is rendered opaque totally or intermittently so that the image of an object cannot be viewed or is hardly viewed.
Inventors
- 👤 Hiroshi Iwata
- 👤 Tetsuo Yamaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:13
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18; G03B17/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
152 words
A view finder for a camera including means for providing a warning of unsatisfactory exposure conditions, comprising: a window through which a subject may be viewed, said window comprising an electro-optical element having a transparent state and an opaque state, the state of said window being determined by an electrical control signal applied thereto; means responsive to a plurality of exposure-affecting conditions of said camera for setting said electrical control signal at a first value when all of said conditions are satisfactory and at a second value when any one of said conditions is unsatisfactory; and a driving circuit connected to said window and responsive to said electrical control signal for (i) rendering the entire window transparent when said electrical control signal has said first value, and (ii) rendering the entire window continuously or intermittently opaque to block the view of said subject when said electrical control signal has said second value.
Claim 2
Dependent Claim
152 words
A view finder for a camera including means for providing a warning of unsatisfactory exposure conditions, comprising: a window through which a subject may be viewed, said window comprising an electro-optical element having a transparent state and an opaque state, the state of said window being determined by an electrical control signal applied thereto; means responsive to a plurality of exposure-affecting conditions of said camera for setting said electrical control signal at a first value when all of said conditions are satisfactory and at a second value when any one of said conditions is unsatisfactory; and a driving circuit connected to said window and responsive to said electrical control signal for (i) rendering the entire window transparent when said electrical control signal has said first value, and (ii) rendering the entire window continuously or intermittently opaque to block the view of said subject when said electrical control signal has said second value.
Claim 3
Dependent Claim
24 words
The view finder according to claim 1, wherein said exposure-affecting conditions comprise the brightness of said subject and the condition of a camera battery.
Claim 4
Dependent Claim
23 words
The view finder according to claim 1, wherein said exposure-affecting conditions include the condition of locking of a lens door of said camera.
Claim 5
Dependent Claim
23 words
The view finder according to claim 1, wherein said exposure-affecting conditions include the state of readiness of an electronic flash for said camera.
Claim 6
Dependent Claim
39 words
The view finder according to claim 1, wherein said view finder includes a plurality of exposure condition warning lights viewable through said window, said lights being continuously or intermittently blocked when said electrical control signal has said second value.
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) | 1986-02-07 | 1986-08-09 | 1987-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-07 | 1990-08-09 | 1991-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-07 | 1994-08-09 | 1995-02-08 | $7700.00 | Window Closed / Lapsed |