US3678828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exposure control device for a camera
Assignee: Canon Inc
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Filing: 1970-10-22
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Granted: 1972-07-25
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Expires: 1990-10-22
Abstract
Abstract An exposure control device for a camera comprising: an electronic shutter control device for shutter actuation, a brightness indicator circuit for indicating and warning insufficient brightness of an object being photographed, and exposure measuring circuit connectable to said brightness indicator circuit and flash ready indicator for a flash exposure, whereby an indicator in said brightness indicator circuit instructs a camera operator to use a flash device and said flash indicator assures camera operator to get a correct flash exposure.
Inventors
- 👤 Yukio Mashimo
- 👤 Mitsuo Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:08
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/083
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
132 words
An apparatus for indicating satisfactory operating conditions for a camera, comprising indicating means for producing indication that distinguish between sufficient and insufficient light, said indicating means including light sensing means and an indicator responsive to said light sensing means, auxiliary light producing means capable of producing auxiliary light, said auxiliary light producing means having a lIght source, said auxiliary light producing means having actuable and variable power means for energizing said source when said power means reaches a given power state and when said power means is actuated, said power means generating a given electrical value when said power means reaches the given power state, and control means connected to said indicating means for varying the response of said indicating means and rendering said indicating means responsive to the given electrical value.
Claim 2
Independent Claim
132 words
An apparatus for indicating satisfactory operating conditions for a camera, comprising indicating means for producing indication that distinguish between sufficient and insufficient light, said indicating means including light sensing means and an indicator responsive to said light sensing means, auxiliary light producing means capable of producing auxiliary light, said auxiliary light producing means having a lIght source, said auxiliary light producing means having actuable and variable power means for energizing said source when said power means reaches a given power state and when said power means is actuated, said power means generating a given electrical value when said power means reaches the given power state, and control means connected to said indicating means for varying the response of said indicating means and rendering said indicating means responsive to the given electrical value.
Claim 3
Dependent Claim
35 words
An apparatus, as in claim 1, wherein the camera includes variable settings, and wherein said control means include regulating means responsive to said setting for operating said indicating means in response to said regulating means.
Claim 4
Dependent Claim
44 words
An apparatus, as in claim 1, wherein said control means includes a lamp connected to said power means to respond to the indication, said sensing means being exposed to said lamp so as to effect the variation in the response of said indicating means.
Claim 5
Dependent Claim
37 words
An apparatus, as in claim 1, wherein said control means includes a magnet responsive to said power means and a switch connected to said sensing means for varying the response of said indicator to said sensing means.
Claim 6
Independent Claim
133 words
An apparatus for indicating satisfactory operating conditions for a camera, comprising a photoconductive member exhibiting varying impedance values in response to variation in the light to which it is exposed, an exposure alarm control circuit having an input circuit connected to said photoconductive means, alarm indicating means connected to respond to said exposure alarm control circuit, said control circuit being actuated by a predetermined actuating level depending upon the impedance of said photoconductive means, an auxiliary light, a power source for said auxiliary light, said power source producing a voltage to indicate readiness to operate said source, a detecting circuit for indicating proper operating conditions of said source, and coupling means in said detecting circuit connected to said input circuit for varying the effective input to a level lower than the actuating level.
Claim 7
Independent Claim
133 words
An apparatus for indicating satisfactory operating conditions for a camera, comprising a photoconductive member exhibiting varying impedance values in response to variation in the light to which it is exposed, an exposure alarm control circuit having an input circuit connected to said photoconductive means, alarm indicating means connected to respond to said exposure alarm control circuit, said control circuit being actuated by a predetermined actuating level depending upon the impedance of said photoconductive means, an auxiliary light, a power source for said auxiliary light, said power source producing a voltage to indicate readiness to operate said source, a detecting circuit for indicating proper operating conditions of said source, and coupling means in said detecting circuit connected to said input circuit for varying the effective input to a level lower than the actuating level.
Claim 8
Dependent Claim
72 words
An apparatus, as in claim 5, wherein said coupling means includes a transistor having a base circuit responsive to said detecting circuit and emitter-collector circuit, a lamp in series with said emitter-collector circuit and positioned to expose said photoconductive member to the light therefrom, said transistor being poled to reduce the impedance of said emitter-collector path in response to an indication from said detecting circuit of proper operating conditions for said source.
Claim 9
Dependent Claim
56 words
An apparatus, as in claim 5, wherein said coupling means includes resistance means connected to said input circuit so as to vary the effect of said photoconductive member upon the operation of said input circuit, switch means in series with said resistance means, and electromagnetic means responsive to said indicating means for operating said switch means.
Claim 10
Dependent Claim
39 words
An apparatus, as in claim 5, wherein said coupling means includes luminous means optically coupled with said photoconductive member and responsive to said detecting circuit so as to be actuated thereby and reduce the impedance of the photoconductive member.
Claim 11
Dependent Claim
64 words
An apparatus, as in claim 5, further comprising setting means for said camera, said detecting circuit including a variable impedance element responsive to said setting means, said setting means being effective to change the focus of said camera, said element being effective to change said detecting circuit to indicate an inoperative condition when said element is moved by said setting means to extreme positions.
Claim 12
Dependent Claim
24 words
An apparatus, as in claim 7, wherein said resistance means and said switching means form a series circuit connected parallel to said photoconductive member
Claim 13
Dependent Claim
40 words
An apparatus, as in claim 7, wherein said resistance means includes a high resistance element and a low resistance element, said switching means being connected alternately in series with each of said resistance elements in response to saiD electromagnetic means.
Claim 14
Dependent Claim
29 words
An apparatus, as in claim 8, wherein said luminous means comprises an electric lamp serving as an indication member for indicating a proper operating condition for said auxiliary light.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |