# US 4,396,264 A · Monocular reflex camera

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- Number: US 4,396,264 A
- Document ID: US4396264A
- Status: Granted
- Kind: A
- Application number: 06/338,808
- Filed: 1982-01-11
- Granted: 1983-08-02
- Earliest claimed: 1981-01-28
- Assignees: Veb Pentacon Dresden Kamera und Kinowerke
- Inventors: Herbert Welzel; Lothar Reschke
- Web page: https://patentgrep.com/patent/US4396264A

## CPC

- G03B 19/12: Reflex cameras with single objective and a movable reflector or a partly-transmitting mirror
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)

## Abstract

A monocular reflex camera having a viewfinder mirror and carrier assembly movable between a viewing position of the camera and an exposure taking position comprises a pivoted crank arm of which the pivot shaft is articulated connected with the mirror carrier close to the centre of gravity. The carrier has a lateral stop lug arrange at a distance from the pivot shaft and protruding into the path of the movement of the crank arm. A spring urges the stop lug into abutment with the crank arm. Stops are provided for locating said mirror assembly in the exposure taking position, and also in the viewfinding position. During the viewing position of the mirror and over a substantial portion of its travel into the exposure taking position, the lug is maintained in engagement with said crank arm by said spring and on arrival at the picture taking position the lug disengages the crank arm against the action of the spring.

## Claims

### Claim 1

A monocular reflex camera having a viewfinder mirror and carrier assembly movable between a viewing position of the camera and an exposure taking position, comprising
(a) a pivoted crank arm of which the pivot shaft is articulated connected with the mirror carrier close to the centre of gravity,
(b) a lateral stop lug on said carrier arranged at a distance from the pivot shaft and protruding into the path of the movement of the crank arm,
(c) a spring which seeks to bring the stop lug into abutment with the crank arm,
(d) first stop means for locating said mirror assembly in the exposure taking position, and
(e) second stop means for locating said mirror assembly in the viewfinding position,
wherein during the viewing position of the mirror and over a substantial portion of its travel into the exposure taking position, the lug is maintained in engagement with said crank arm by said spring and on arrival at the picture taking position the lug disengages the crank arm against the action of the spring.

### Claim 2 (depends on 1)

A camera according to claim 1, wherein the pivot shaft is connected with the mirror carrier at a distance from the centre of gravity remote from the mirror pivot axis.

### Claim 3 (depends on 1)

A camera according to claim 1, wherein the pivot shaft is made integral with a pair of crank arms and journals.