Patent US4253756A successfully refreshed from Google Patents.
US4253756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three operational mode camera
Assignee: Pentax Corp
•
Filing: 1980-01-17
•
Granted: 1981-03-03
•
Expires: 2000-01-17
Abstract
Abstract A camera having an automatic exposure control mechanism wherein aperture priority, shutter speed priority and manual modes of operation can be set without the possibility of the switching mechanism being set to inoperable positions. The aperture ring of the camera lens is provided with a protrusion which interlocks with a corresponding protrusion on a ring of the camera body through which aperture information is transmitted. The shutter dial of the camera is provided on its reverse side with plural semicircular conductive pads which selectively engage with contact brushes as the dial is rotated to set the various modes of operation. A variable resistance contact portion is also provided on the dial for manually setting the shutter speed.
Inventors
- 👤 Hiroshi Kurei
- 👤 Tahei Morisawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:09
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/0805; G03B7/081; G03B7/087
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
126 words
A camera including an automatic exposure control mechanism for aperture-priority and shutter-speed-priority and a manual exposure control mechanism for manually setting an aperture value and a shutter speed comprising: a three-photographing mode switching means having an indication member operated in association with a photographing mode switching member, said indication member having a series of control regions including an aperture-priority automatic exposure control region, a shutter-speed-priority automatic exposure control region divided into parts corresponding to available shutter speed values, and a manual exposure region divided into parts corresponding to said available shutter speed values, said manual exposure region confronting a stationary index means so that said camera is set in an operational mode corresponding to an indication obtained by continuous displacement of said photographing mode switching member.
Claim 2
Dependent Claim
126 words
A camera including an automatic exposure control mechanism for aperture-priority and shutter-speed-priority and a manual exposure control mechanism for manually setting an aperture value and a shutter speed comprising: a three-photographing mode switching means having an indication member operated in association with a photographing mode switching member, said indication member having a series of control regions including an aperture-priority automatic exposure control region, a shutter-speed-priority automatic exposure control region divided into parts corresponding to available shutter speed values, and a manual exposure region divided into parts corresponding to said available shutter speed values, said manual exposure region confronting a stationary index means so that said camera is set in an operational mode corresponding to an indication obtained by continuous displacement of said photographing mode switching member.
Claim 3
Dependent Claim
24 words
The camera of claim 1 wherein said manual exposure region comprises a resistance member for providing different resistance values indicative of different shutter speeds.
Claim 4
Dependent Claim
14 words
The camera of claim 1 wherein said indication member comprises a rotatable disc-shaped member.
Claim 5
Dependent Claim
19 words
The camera of claim 3 further comprising means for stopping rotation of said disc-shaped member at predetermined rotational positions.
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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |