Reflex camera view finder

Claim 2

In a reflex camera having an objective lens, a shutter and view finding means including a ground glass and a mirror to intersect the light beam from the lens to reflect an image of the subject onto the ground glass, the improvement comprising: a view finder chamber the mirror and ground glass being fixed parts of a view finder chamber, said chamber being movable between a view finding position at which the chamber intersects the beam of light from the lens to cause the mirror to reflect an image of the subject onto the ground glass and a picture-taking position at which the view finder chamber is clear of the beam of light, said chamber having an opening to admit the beam of light from the camera lens; means to move the view finder chamber to its two positions alternately; and a light shield operative to cover said opening to prevent light from entering the camera through the view finder chamber when the chamber is in the picture-taking position, said light shield being movably mounted on the view finder chamber and being mechanically responsive to movement of the view finder chamber to uncover said opening when the chamber approaches the view finding position and to cover the opening when the chamber approaches the picture-taking position.

Claim 3

An improvement as set forth in claim 1 in which the camera has fixed structure adjacent the view finder chamber; and which includes cooperative means on the chamber and on the fixed structure respectively to move the light shield to its open position in response to approach of the chamber to its view finding position.

Claim 4

An improvement as set forth in claim 2 in which the light shield is spring-biased to seek its closed position when movement of the chamber out of its view finding position retracts the cooperative means on the chamber from said fixed structure.

Claim 5

An improvement as set forth in claim 3 in which said light shield is pivoted to move in its own plane between its two positions.

Claim 6

An improvement as set forth in claim 3 in which the light shield is pivotally mounted and in which the cooperative means on the view finder chamber is a rod pivotally connected to the light shield.

Claim 7

An improvement as set forth in claim 5 in which said rod extends through an aperture in the wall of the view finder chamber.

Claim 8

An improvement as set forth in claim 2 in which the cooperative means on the chamber extends to the exterior of the chamber in a position to encounter said fixed structure for actuation thereby to shift the light shield to its open position in response to approach of the chamber to its view finding position.

Claim 9

In a reflex camera having an objective lens, a shutter and view finding means including a ground glass and a mirror to intersect the light beam from the lens to reflect an image of the subject onto the ground glass, the improvement comprising: a view finder assembly the mirror and ground glass being fixed parts of said view finder assembly for maintenance of constant spatial relationship between the mirror and the ground glass; said view finder assembly being movable as a whole between a view finding position at which the assembly intersects the beam of light from the lens to cause the mirror to reflect an image of the subject onto the ground glass and a picture-taking position at which the view finder assembly is clear of the beam of light; and a power actuated crank movable between two opposite positions and operatively connected to the view finder assembly to move the view finder assembly between its two alternate positions; the crank at each of its two opposite positions being on a diameter of the orbit of the crank that is parallel with the direction of travel of the view finder assembly whereby the movement of the assembly from each of its two alternate positions to the other position is sinusoidal with the assembly accelerating towards the midpoint of its travel and decelerating from the midpoint towards the end of its travel.

Claim 10

In a reflex camera having an objective lens, a shutter and view finding means including a ground glass and a mirror to intersect the light beam from the lens to reflect an image of the subject onto the ground glass, the improvement comprising: a view finder assembly the mirror and ground glass being fixed parts of said view finder assembly for maintenance of constant spatial relationship between the mirror and the ground glass; said view finder assembly being movable as a whole between a view finding position at which the assembly intersects the beam of light from the lens to cause the mirror to reflect an image of the subject onto the ground glass and a picture-taking position at which the view finder assembly is clear of the beam of light; and a power actuated crank movable between two opposite positions and operatively connected to the view finder assembly to move the view finder assembly between its two alternate positions; the crank at each of its two opposite positions being on a diameter of the orbit of the crank that is parallel with the direction of travel of the view finder assembly whereby the movement of the assembly from each of its two alternate positions to the other position is sinusoidal with the assembly accelerating towards the midpoint of its travel and decelerating from the midpoint towards the end of its travel.