Patent US3883252A successfully refreshed from Google Patents.
US3883252A
Expired / Lapsed
US
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Exposure meter device
Assignee: Pentax Corp
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Filing: 1973-08-28
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Granted: 1975-05-13
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Expires: 1993-08-28
Abstract
Abstract An exposure meter device indicates which exposure range out of preferably five different indicatable exposure ranges has been selected as the one into which an exposure amount has been regulated. A plurality, preferably three, electrically energizable illuminative elements provide for displaying a visual indication of the selected exposure range. Photosensitive transducing means and circuit means responsive thereto provide for energizing the illuminative elements and are operative to cause at least one of the elements to flicker as an indication of one exposure range and to be continuously illuminated as an indication of another exposure range.
Inventors
- 👤 Hirokazu Ando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:27
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18; G01; G01J; G01J1/00; G01J1/42; G01J1/4209; G01J1/4214; G03B17/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
276 words
An exposure meter device for indicating which one of a plurality of exposure ranges has been selected as the one into which an exposure amount has been regulated, which comprises: a plurality of electrically energizable illuminative elements for displaying a visual indication of the selected exposure range, at least a first one of the elements being exclusively pre-assigned to indicate a pair of exposure ranges that differ slightly and grossly respectively from a normally optimum exposure range, one of the pair being indicated by flickering of the first element, the other of the pair being indicated by continuous illumination of the first element; photosensitive transducing means for providing an electrical signal indicative of the regulated exposure amount, electrical signal varying relative to a plurality of threshold values that define a plurality of electrical signal ranges each of which corresponds to a different one of the exposure ranges; and circuit means coupled to receive the electrical signal and responsive to the electrical signal''s value relative to the threshold values for selectively energizing the illuminative elements so that they display the visual indication, the circuit means including a first circuit having a plurality of output terminals, each of a first plurality of the output terminals being connected to a different one of the elements, the first circuit operating to connect on a one-at-a-time basis any one of the elements into a current flow path, and the circuit Means further including switching means in the current flow path and controllable by the first circuit either to maintain a steady current flow or to cause pulsating current flow and thereby cause either continuous or flickering illumination of the selected element.
Claim 2
Dependent Claim
276 words
An exposure meter device for indicating which one of a plurality of exposure ranges has been selected as the one into which an exposure amount has been regulated, which comprises: a plurality of electrically energizable illuminative elements for displaying a visual indication of the selected exposure range, at least a first one of the elements being exclusively pre-assigned to indicate a pair of exposure ranges that differ slightly and grossly respectively from a normally optimum exposure range, one of the pair being indicated by flickering of the first element, the other of the pair being indicated by continuous illumination of the first element; photosensitive transducing means for providing an electrical signal indicative of the regulated exposure amount, electrical signal varying relative to a plurality of threshold values that define a plurality of electrical signal ranges each of which corresponds to a different one of the exposure ranges; and circuit means coupled to receive the electrical signal and responsive to the electrical signal''s value relative to the threshold values for selectively energizing the illuminative elements so that they display the visual indication, the circuit means including a first circuit having a plurality of output terminals, each of a first plurality of the output terminals being connected to a different one of the elements, the first circuit operating to connect on a one-at-a-time basis any one of the elements into a current flow path, and the circuit Means further including switching means in the current flow path and controllable by the first circuit either to maintain a steady current flow or to cause pulsating current flow and thereby cause either continuous or flickering illumination of the selected element.
Claim 3
Dependent Claim
80 words
A device according to claim 1, wherein the switching means comprises a pair of transistors which are connected in parallel circuit relationship with respect to each other and that are connected in series circuit relationship with respect to the first circuit, an oscillator for driving one of the pair of transistors on and off, the other of the pair of transistors being turned on or off by the first circuit in accordance with the relative value of the electrical signal.
Claim 4
Dependent Claim
93 words
A device according to claim 1, wherein the switching means comprises a resistor and a transistor that are connected in parallel circuit relationship with respect to each other and that are connected in series circuit relationship with respect to the first circuit, an oscillator circuit for controlling the transistor, and means responsive to the first circuit for turning the oscillator circuit on or off so that current in the current flow path either flows steadily unaffected by the transistor or pulses at the cyclical rate of turning on and off of the transistor.
Claim 5
Dependent Claim
118 words
An exposure meter device for indication of regulated exposure amount, which comprises a plurality of electrically energizable illuminative elements, photometric and circuit means adapted to illuminate on a one-at-a-time basis any selected one of the elements, the circuit means including a circuit having a plurality of output terminals, the elements being arranged in parallel and each being connected to a different one of the output terminals, and a relaxation oscillator, wherein the selected element may be steadily illuminated when a regulated exposure amount is excessive or deficient relative to an optimum exposure within a range defined by a predetermined value and may be caused to flicker by placing energization of the element under control of the relaxation oscillator.
Claim 6
Dependent Claim
118 words
An exposure meter device for indication of regulated exposure amount, which comprises a plurality of electrically energizable illuminative elements, photometric and circuit means adapted to illuminate on a one-at-a-time basis any selected one of the elements, the circuit means including a circuit having a plurality of output terminals, the elements being arranged in parallel and each being connected to a different one of the output terminals, and a relaxation oscillator, wherein the selected element may be steadily illuminated when a regulated exposure amount is excessive or deficient relative to an optimum exposure within a range defined by a predetermined value and may be caused to flicker by placing energization of the element under control of the relaxation oscillator.
References Cited (Backward Citations)
US3724955A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |