Patent US4397534A successfully refreshed from Google Patents.
US4397534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for displaying bulb photographing operation time in a photographic camera
Assignee: Canon Inc
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Filing: 1982-05-19
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Granted: 1983-08-09
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Expires: 2002-05-19
Abstract
Abstract A display device for displaying the time of a bulb photographing operation is arranged so that a counter for counting the clock pulses starts to operate when the bulb photographing mode is set in the camera and the release operation of the camera is started. A decoder incorporated in the camera decodes the content of the counter and a display instrument displays the output of the decoder in such a manner that the photographer can visually recognize the bulb photographing operation time. Several embodiments of the circuitry for controlling the nature of the display, including timing charts therefor, are set forth.
Inventors
- 👤 Nobuaki Sakurada
- 👤 Nobuaki Date
- 👤 Masami Shimizu
- 👤 Hiroshi Aizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:19
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
A display device for a photographic camera, comprising: (a) means for producing a release signal in response to a release operation of the camera; (b) means for producing a bulb phtographing setting signal in response to setting of a bulb photographing mode of camera operation; (c) a counter for counting a number of input pulses and providing a counter output; (d) a decoder for decoding the output of the counter; (e) display means for displaying the output of the counter; and (f) control means for enabling the display means to display the output of the counter the content of which varies successively, when both of the release signal and the bulb photographing setting signal are applied to input terminals of the control means.
Claim 2
Dependent Claim
123 words
A display device for a photographic camera, comprising: (a) means for producing a release signal in response to a release operation of the camera; (b) means for producing a bulb phtographing setting signal in response to setting of a bulb photographing mode of camera operation; (c) a counter for counting a number of input pulses and providing a counter output; (d) a decoder for decoding the output of the counter; (e) display means for displaying the output of the counter; and (f) control means for enabling the display means to display the output of the counter the content of which varies successively, when both of the release signal and the bulb photographing setting signal are applied to input terminals of the control means.
Claim 3
Dependent Claim
42 words
A display device according to claim 1, wherein the control means comprises of a gate circuit including a first input terminal connected to the release signal producing means and a second input terminal connected to the bulb photographing setting signal producing means.
Claim 4
Dependent Claim
45 words
A display device according to claim 2, wherein the gate circuit includes an AND gate coupled to a reset terminal of the counter for initiating the counting operation of the counter upon receipt of both of the release signal and the bulb photographing setting signal.
Claim 5
Dependent Claim
117 words
A display device for a photographic camera, comprising: (a) means for producing a release signal in response to a release operation of the camera; (b) means for producing a bulb photographing setting signal in response to setting of a bulb photographing mode of camera operation; (c) a counter for counting a number of input pulses and providing a counter output; (d) a decoder for decoding the output of the counter; (e) display means for displaying the output of the counter; and (f) control means for enabling the display means to display the output of the counter the content of which varies successively, after both of the release signal and the bulb photographing setting signal have been produced.
Claim 6
Dependent Claim
117 words
A display device for a photographic camera, comprising: (a) means for producing a release signal in response to a release operation of the camera; (b) means for producing a bulb photographing setting signal in response to setting of a bulb photographing mode of camera operation; (c) a counter for counting a number of input pulses and providing a counter output; (d) a decoder for decoding the output of the counter; (e) display means for displaying the output of the counter; and (f) control means for enabling the display means to display the output of the counter the content of which varies successively, after both of the release signal and the bulb photographing setting signal have been produced.
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) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |