Shutter and viewfinder mirror inter-linkage means for a small single-lens reflex camera

Claim 1

In a single-lens reflex camera having a lens system along whose optical axis light reflected from external objects may be directed into the interior of said camera to be directed into a viewfinder observable by a photographer or to expose a film, a guillotine-type shutter comprising a first curtain and a second curtain, each of which is independently moveable, is normallY urged to and remains in a repose position, wherein it permits passage of light directed into said camera by said lens system, and is moveable to and retainable in a cocked position, wherein it permits passage of said light, electronically controlled means which is actuated simultaneously with release of said first curtain from said cocked position and subsequently holds said second curtain in said cocked position for a time that is variable in accordance with ambient light conditions, and a pivotally mounted mirror, which is moveable to first mirror position wherein said mirror permits light directed into said camera by said lens system and passed by said shutter to reach and expose a film, and to a second mirror position wherein said mirror prevents said light from reaching a film and directs said light into said viewfinder, a shutter and mirror interlinkage means comprising a first retention means which, subsequent to release of said first curtain from said cocked position, retains said first curtain in a first curtain intermediate position wherein said first curtain prevents passage of light directed into said camera by said lens system. first mirror pivot means exerting a constant force urging said mirror to move to said first mirror position mirror retention means which may hold said mirror in said second mirror position, and is actuated to disengage said mirror by said first curtain at said first curtain intermediate position first disengagement means which may effect disengagement of said first retention means from said first curtain, whereby said first curtain may be moved from said first curtain intermediate position to said repose position, and permit commencement of a film exposure, and which is actuated by said mirror at said mirror first position second retention means which, subsequent to release of said second curtain from said cocked position, retains said second curtain in a second curtain intermediate position wherein said second curtain prevents passage of light directed into said camera by said lens system, whereby a film exposure is terminated second mirror pivot means which may move said mirror to said second mirror position, and is actuated by said second curtain at said second curtain intermediate position second disengagement means which may effect disengagement of said second retention means from said second curtain, whereby said second curtain may be moved from said second curtain intermediate position to said repose position, and which is actuated by said mirror at said second mirror position.