Registration apparatus for television film projection system

Claim 1

In a television film projection system, registration apparatus for accurately positioning on a storage-type photosensitive electrode of a camera tube during each vertical blanking interval a momentary light replica, produced by light from a stroboscopic light source, of each of a series of imagebearing frames of an image recording film also having, in a marginal strip adjacent said image-bearing frames, lateralposition-identifying indicia having a precise spacing from respective ones of said image-bearing frames, said registration apparatus comprising: a series arrangement in a main light transmission path from said stroboscopic light source to the photosensitive electrode of said camera tube of a first dichroic mirror, said film and a second dichroic mirror, each of said dichroic mirrors being angularly positioned relative to said main light transmission path and functioning (1) to direct light of a first color emanating from said stroboscopic light source through the image-bearing frames of said film and along said main light transmission path to said camera tube electrode and (2) to direct light of a second color along that part of said main light transmission path between said dichroic mirrors and also along first and second auxiliary light transmission paths branching respectively from said first and second dichroic mirrors; light-producing means located in one of said auxiliary light transmission paths for continuously supplying light of said second color to the dichroic mirror associated with said one auxiliary light transmission path; photodetecting means located in the other one of said auxiliary light transmission paths and responsive to light of said second color received from the dichroic mirror associated with said other auxiliary light transmission path and derived from said lateral-position-identifying indicia to develop triggering pulses for momentarily actuating said stroboscopic light source to produce short duration flashes of light of said first color for projection through respective ones of said image-bearing frames of said film; and light-direction-changing means located in said main light transmission path between said film and said dichroic mirror associated with the auxiliary light path including said photodetecting means for producing lateral movement relative to said camera tube electrode of a light replica of each of said image-bearing frames of said film, whereby said stroboscopic light source is actuated only when the light replica of each image-bearing frame is accurately positioned on said camera tube electrode.