Roof-type reflecting mirror for viewfinder of single lens reflex camera

Claim 1

A viewfinder structure for a single lens reflex camera having a rectangular horizontal focusing plate comprising: first and second opposed parallel lateral walls spaced apart a distance substantially equal to one side of the focusing plate, said walls having bottom edges adapted to contact the camera body on opposite sides of the focusing plate and parallel front edges extending upward and forward from the bottom edges; a roof-type wall extending inwardly and upwardly from each lateral wall, each said roof-type wall having a flat reflecting internal surface, said internal surfaces meeting at a desired angle less than 180* along a line of intersection, said line of intersection extending forward and upward at an acute angle relative to the plane of the focusing plate; a triangular front wall extending between the roof-type walls and having a bottom edge extending between the lines of intersection between the roof-type walls and the lateral walls; a mirror frame formed by said bottom edge of the front wall cooperating with the front edges of the lateral walls; a plane reflecting mirror positioned within said mirror frame, said reflecting mirror extending upward and forward from the forward edge of the focusing plate when said viewfinder structure is in place on the camera body; an eyepiece-holding frame extending between the lateral walls adjacent the lower edges thereof at the rear of said lateral walls; said first and second lateral walls, roof-type walls, front wall, and eyepiece-holding frame being integrally formed of plastic.