Patent GB-1283933-A (GB)
Title: Improvements relating to photographic apparatus
IPC: G03B19/18
Filed: 1969-10-31
Abstract: 1283933 Self-processing cassettes POLAROID CORP 31 Oct 1969 [1 Nov 1968] 53577/69 Heading G2A and G2E A motion picture apparatus includes a cassette 10 containing film strip which may be wound on or off reels 16, 18, and an applicator 52 for applying processing liquid to the film strip 14, the applicator being movable between an operative and a non-operative position. It is mounted between guide plates 48, 50, and can slide from the operative position shown in Fig. 1 to its non- operative position by moving in a right-hand direction. The film is initially wound on reel 16, and the cassette is mounted in a camera (not shown) for the picture-taking operation, during which the film is driven from reel 16 to reel 18. The cassette is now removed from the camera, and mounted in a projector 12. The projector includes a motor 46 which can drive either reel 16 or reel 18. One edge of applicator 52 has a rack 58, which engages with a pinion 60 connected to an arm 62 which is external of the cassette. By means of a handle 64 at the end of arm 62, the pinion can be rotated so as to move the applicator towards or away from the film. An arm 70 is mounted on a pin 68 which extends through the door of the projector and ends in a knob (74), Fig. 2 (not shown). Arm 70 is tensioned by an over-the-centre spring 72. Thus, after applicator 52 has been moved to the left by pinion 60, into its operative position, the projector door may be closed and the knob (74) turned anti-clockwise, so that arm 70 is urged against handle 64 by spring 72, so maintaining the applicator in its operative position. The viscous processing material 53 can be expelled through an orifice 54 so as to be applied to the film strip. The orifice has a knife edge (84) to minimise streaking, and is normally covered by a strip of vinyl 86 permanently attached at one end to the cassette. When the applicator is moved into its operative position, this strip is automatically peeled away to uncover the orifice. The projector includes a rod 98 slidably positioned in a mount 100 and having at its rearward end a block 102 which can slide along a guide track 106. The block has a spring-loaded knob (118), Figs. 4, 5, 6 (not shown) which extends exteriorly of the projector through a slot 116 therein. When the knob (and hence block 102 and also rod 98) is moved to its extreme right-hand position, it seats in a recess (122) and is locked by its spring in this position. A "Negator" (Trade Mark) spring 138 is attached at one end to block 102 and at its other end to a fixed bracket 136. Thus, as the block is retained in its extreme righthand position, it is being urged to the left by spring 138. The other end of rod 98 is aligned with apertures 140 and 141 in the cassette 10 and applicator 52 respectively. When block 102 is released by disengaging its knob (118) from its recess (122), the block is pulled to the left by spring 138, until the end of rod 98 enters aperture 141 and engages against a plunger 56 in the applicator. Motor 46 is now energized, and drives spool 16 to take up the film which is wound on spool 18. As the film passes the orifice 54, the processing material 53 is metered out under constant pressure by means of the constant force of spring 138 acting on plunger 56. As the film wound on spool 16 increases in diameter, the film tends to move more quickly past the applicator. This is counteracted by the action of a lever 154, one end 158 of which is linked to a pin 162 on block 102, and the other end 156 of which is linked to a slider 152 of a potentiometer 150. Thus as lever 154 gradually pivots clockwise as the material 53 is expelled from applicator 52, the resistance of potentiometer 150 alters and so reduces the speed of motor 46. When the processed film has been completely wound onto spool 16, motor 46 is reversed, and the film once more winds from spool 16 to spool 14. This time an illuminating system 32, 34 is switched on, and the apparatus is now used as a projector.