ARRANGEMENT FOR RECORDING AND REPRODUCING HOLOGRAMS OF MOVING SUBJECTS

1,204,873. Cinematography; holography. AGFA-GEVAERT A.G. Sept.19, 1967 [Sept.21 1966], No.42532/67. Headings G2C, G2E and G2J. [Also in Divisions G5 and H4] In a process for the recording and reproduction of moving pictures, holographic images of the pictures are recorded on a carrier 10, which may be a rotatable disc or a tape, the images comprising a series of very narrow transverse bands, such that when the carrier is moved continuously past a laser beam illumination and scanning device for reproduction of the moving pictures, no appreciable change in viewpoint is seen. The moving pictures are initially recorded on a conventional cine film 9 whose individual frames are then photographed on to discontinuously moving carrier 10 through a narrow slit in diaphragm 11 using a laser source and reference beam to provide a number of hologram bands for each frame. In an alternative form, film 9 is placed at the focus of a collimating lens such that carrier 10 receives only parallel light, and again no viewpoint change occurs on reproduction. By using different relationships between object and reference waves, multiple separate images may be recorded at the same location on the carrier. These multiple images may each comprise one of a sequence of cine frames, whereby each sequence may be reproduced by adjusting the position of the scanning device. Alternatively, these images may be the colour component images of a full-colour picture and may be reproduced using different wavelength optically superposed laser beams and scanning devices at the necessary inclination to the beam axis. Absorption or phase holograms may be recorded on a transparent carrier, or relief holograms may be formed on a reflective carrier comprising a silvered thermoplastics base. Sound may be recorded on the underside of the carrier as the multi-channel hologram of a laser amplitude which is modulated at the audio-frequency. The sound recording may be in the form of a conventional stylus groove when the picture holograms are in relief on a disc. The scanning device may comprise vidicon tube (19), Fig7 (not shown), of a television camera, the laser (18) and tube being traversed radially across the disc carrier (14) by means of a U-shaped bracket (17) powered by motor (16). The inclination (#) of the vidicon to the laser beam may be varied for each traverse. In place of the vidicon optical scanning means such as mirrors and prisms as fibre-optic elements may be used.