Patent GB-1157985-A (GB)
Title: Improvements relating to Photographic Apparartus for Processing and Exhibiting Colour Separation Records
IPC: G03D11/00
Filed: 1966-07-06
Abstract: 1,157,985. Photographic apparatus; automatic position control of moving webs. INTERNATIONAL POLAROID CORP. July 6, 1966 [July 16, 1965], No. 11285/69. Divided out of 1, 157, 984. Headings G2A and G3R. Photographic apparatus for processing and exhibiting photographic material which has an overall distribution of silver halides sensitive to light of at least two different colours which has been exposed to a coloured original to produce at least two latent silver image colour separation records and exhibit the records after development to reproduce the original in colour, the apparatus comprising a source of white light, means for positioning the exposed material; a colour filter with different areas which pass colours complementary to the colours to which the silver halides respond, the filter being positioned between the source and the exposed material so that the material can be fogged to produce a late at silver record of the fogging exposure; means for photographically processing the latent silver records by a reversal process to form visible silver image, these silver images together forming the colour separation records and exhibiting means, including an image projector, a screen and colour-selective means having different areas corresponding in arrangement and complementary in colour to the different areas of the colour filter and being so arranged in relation to the projector and the screen that each of the colour seperation records is exhibited in the light of the colour it represents. As shown, a combined processing and projection apparatus consists of a spool 40 of exposed light-sensitive material 42 containing an image-receiving layer which is threaded past a film gate 48 and a window 52 where the exposed film is subjected to a fogging exposure to a cyan, magenta and yellow line screen placed in the window, light being provided by source 44 and passing through condenser lenses 46 and being reflected by mirrors 56 and 58. Alternatively, the exposed material may be fogged by placing the line screen at the film gate 48 and pivoting mirror 56 out of the light path. The material now passes through processing chamber 60 to develop a silver image in the receiving material and then through chamber 66 containing liquid for softening the photo-sensitive layers and a squeegee 68 so that the photo-sensitive layers are stripped off. The image containing layer and support are rolled up on spool 72. For projection the film is threaded round rollers 70 and 54 and is projected at film gate 48 using a red, blue and green line screen through projector lens 50. It is stated that the exposed film may be fogged before winding on to spool 72 and the film is then processed at 60 and projected at 48. Correct projection of an additive colour photograph which consists of a multi-colour line screen and a film containing a silver image is maintained by printing a coloured line down one side of the film so that when this film is projected on to the screen 80 (of Fig. 3), the line is projected through slits 82 in the screen and is sensed by photo-electric cells 84. If there is a misalignment of the line image, this information is fed back to the film gate via the D. C. amplifier 88 and servo 86 so that the film can be correctly aligned. If the top and bottom servos are capable of independent movement both linear and rotational correction to the film can be effected.