US3737240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exposure indicator in a photographic camera
Assignee: Agfa Gevaert AG
•
Filing: 1971-12-23
•
Granted: 1973-06-05
•
Expires: 1991-12-23
Abstract
Abstract A photoelectric element furnishes a signal corresponding to the light available for an exposure. The photoelectric element is connected to a plurality of threshold stages. A plurality of indicator elements which glow when energized are arranged in space and connected to the threshold stages in such a manner that glowing indicator elements form a figure signifying the particular exposure time range.
Inventors
- 👤 K Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:07
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/44; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/083
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
163 words
In a photographic camera an indicator arrangement furnishing a plurality of symbols each signifying a predetermined exposure range, comprising, in combination, photosensitive means mounted to receive light available for an exposure and furnishing a first signal corresponding thereto; a plurality of threshold means corresponding in number to said plurality of symbols connected to said photosensitive means, each for furnishing a threshold signal in response to a corresponding predetermined amplitude of said first signal; a plurality of indicator elements for furnishing visual outputs constituting said symbols when energized; first connecting means connecting said plurality of indicator elements into a plurality of groups, at least one of said groups having at least two of said indicator elements; and secOnd connecting means connecting each of said groups of indicator elements to a corresponding one of said threshold means in such a manner that all of the indicator elements of group are energized in response to said threshold signal of said corresponding one of said threshold means.
Claim 2
Dependent Claim
163 words
In a photographic camera an indicator arrangement furnishing a plurality of symbols each signifying a predetermined exposure range, comprising, in combination, photosensitive means mounted to receive light available for an exposure and furnishing a first signal corresponding thereto; a plurality of threshold means corresponding in number to said plurality of symbols connected to said photosensitive means, each for furnishing a threshold signal in response to a corresponding predetermined amplitude of said first signal; a plurality of indicator elements for furnishing visual outputs constituting said symbols when energized; first connecting means connecting said plurality of indicator elements into a plurality of groups, at least one of said groups having at least two of said indicator elements; and secOnd connecting means connecting each of said groups of indicator elements to a corresponding one of said threshold means in such a manner that all of the indicator elements of group are energized in response to said threshold signal of said corresponding one of said threshold means.
Claim 3
Dependent Claim
15 words
An arrangement as set forth in claim 1, wherein said indicator elements are semiconductor elements.
Claim 4
Dependent Claim
15 words
An arrangement as set forth in claim 2, wherein said semiconductor elements are glow diodes.
Claim 5
Dependent Claim
27 words
An arrangement as set forth in claim 1, further comprising connecting means connecting the inputs of all of said threshold means in common to said photosensitive means.
Claim 6
Dependent Claim
21 words
An arrangement as set forth in claim 4, wherein all of said indicator elements together form the shape of a tripod.
Claim 7
Dependent Claim
34 words
An arrangement as set forth in claim 5, wherein all of said indicator elements are energized and luminescent when said first signal has a magnitude below the threshold of any of said threshold means.
Claim 8
Dependent Claim
53 words
An arrangement as set forth in claim 6, wherein said plurality of threshold means comprise a first threshold stage having a threshold corresponding to a maximum required exposure time; and wherein the indicator elements remaining energized after said first signal exceeds the threshold of said first threshold stage form a straight line band.
Claim 9
Dependent Claim
45 words
An arrangement as set forth in claim 7, wherein said plurality of threshold means comprise a plurality of threshold stages; and wherein the number of luminescent indicator elements is a function of the number of threshold stages whose threshold is exceeded by said first signal.
Claim 10
Dependent Claim
33 words
An arrangement as set forth in claim 8, wherein the number of luminescent indicator elements is inversely proportional to the number of said threshold stages whose threshold is exceeded by said first signal.
Claim 11
Dependent Claim
90 words
An arrangement as set forth in claim 4, further comprising a source of electrical energy; and wherein each of said threshold means comprise transistor means having an emitter-collector circuit connected to said source of electrical energy and a base, and thyristor means having a gate connected to said photosensitive means and an anode-cathode circuit connected to said base of said transistor means; and wherein said second connecting means connect each of said groups of indicator elements in series with said emitter-collector circuit of a corresponding one of said transistor means.
Claim 12
Dependent Claim
57 words
An arrangement as set forth in claim 10, further comprising a plurality of first resistors, each connected between said cathode of a corresponding one of said thyristor means and said source of electircal energy, for creating a threshold value in each of said threshold means differing from the threshold value of the others of said threshold means.
Claim 13
Dependent Claim
78 words
An arrangement as set forth in claim 11, wherein each of said bases of said transistor means is directly connected to said anode of said corresponding one of said thyristor means; further comprising a plurality of second resistor means each connected from the base of a corresponding one of said transistors to said source of electrical energy in such a manner that each of said transistors is conductive when the corresponding one of said thyristor means is non-conductive.
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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |