US4304472A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Camera system
Assignee: Canon Inc
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Filing: 1976-11-01
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Granted: 1981-12-08
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Expires: 1996-11-01
Abstract
Abstract In the disclosed photographic exposure control system, an exposure mechanism generates at least one controllable exposure parameter for regulating the exposure of a photosensitive material. A coding circuit is set to produce digital signals corresponding to at least one photographic value. A control device between the coding circuit and the exposure mechanism calculates the exposure parameter and controls the coding circuit. The coded values are then suitably displayed to the photographer.
Inventors
- 👤 Nobuhiko Shinoda
- 👤 Nobuaki Sakurada
- 👤 Masaharu Kamamura
- 👤 Tadashi Ito
- 👤 Fumio Ito
- 👤 Hiroyashu Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:25
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/091; G03B7/0805; G03B7/081; G03B7/087; G03B7/089; G03B7/16; G03B2217/00; G03B2217/005
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
156 words
A digital exposure parameter indicating device for a camera comprising: (a) a digital signal source for generating a digital data signal corresponding to the digital exposure parameter in the form of a binary number; (b) first means for generating a signal representing the lowest step of the exposure parameter; (c) adder circuit means connected to said digital signal souce and to said first means for adding the signal from the first means representing the lowest step of the exposure parameter to a first bit of the digital data signal; (d) a decoder connected to the adder circuit means for converting a binary number composed of bits from an order next to the first bit to a most significant bit of the added digital data signal into a decimal number; and (e) indicating means connected to said decoder for indicating the digital exposure parameter as a decimal number in response to the output signal of said decoder.
Claim 2
Dependent Claim
156 words
A digital exposure parameter indicating device for a camera comprising: (a) a digital signal source for generating a digital data signal corresponding to the digital exposure parameter in the form of a binary number; (b) first means for generating a signal representing the lowest step of the exposure parameter; (c) adder circuit means connected to said digital signal souce and to said first means for adding the signal from the first means representing the lowest step of the exposure parameter to a first bit of the digital data signal; (d) a decoder connected to the adder circuit means for converting a binary number composed of bits from an order next to the first bit to a most significant bit of the added digital data signal into a decimal number; and (e) indicating means connected to said decoder for indicating the digital exposure parameter as a decimal number in response to the output signal of said decoder.
Claim 3
Dependent Claim
225 words
A digital exposure parameter indicating device according to claim 1, wherein said digital signal source includes: (a) timing pulse generating means which produces a plurality of timing pulses in sequence; (b) a single data output line; (c) a digital data plate provided with a pattern composed of a plurality of conductive marks which represent the exposure parameter; (d) scanning means coupled to said pulse generating means and said plate for receiving said timing pulses and scanning the marks of said digital data plate one after another in synchronism with each timing pulse; (e) means coupled to said scanning means for supplying the output digital signals of said scanning means corresponding to the states of said marks one after another to said single data output line; (f) light sensitive means for producing an electrical signal corresponding to the brightness of an object to be photographed; (g) analog-to-digital converter means connected to said light sensitive means for producing a digital signal in the form of a binary number corresponding to the electrical signal from the light sensitive means; and (h) calculating means coupled to the converter means and said output line for producing a digital signal in the form of a binary number corresponding to a digital signal from said single data output line representing a binary number and to the digital signal from said analog-to-digital coverter.
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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) | 1984-12-07 | 1985-06-08 | 1985-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-07 | 1989-06-08 | 1989-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-07 | 1993-06-08 | 1993-12-08 | $7700.00 | Window Closed / Lapsed |