GB1285943A - Photographic camera - Google Patents

Abstract

1285943 Film advancing mechanism EASTMAN KODAK CO 22 Aug 1969 [23 Aug 1968] 41991/69 Heading G2A A camera in which an electric motor advances across the exposure aperture of a film strip having coded indicia has sensing means responsive to the coded indicia controlling the motor, so that when, according to the indicia, a full film frame has been advanced, the motor is de-energized and braked. As shown in Fig. 1, the film strip 12 winds across from supply spool 11 to take-up spool 2 under the action of the electric motor 1 energized by a battery 10. The film has indicator perforations 4, spaced apart the distance of one frame. Fixed to the camera housing are spring arms 13, 14, having respective contacts 6, 9 at their free ends. A further spring arm 5 is normally biased downwards so when an extension pawl 3 enters a perforation 4, arm 5 is biased into contact with contact 6. Fig. 1 shows the mechanism just prior to completion of the exposure, the motor being shorted and the film stationary. After completion of the exposure a cam 7 is rotated anti-clockwise, lifting arm 5 from contact 6 to contact 9 Fig. 2 (not shown) and bringing pawl 3 out of the perforation 4. The battery is now in series with the motor, which is energized to drive spool 2 and transport the film. When the shutter is set, pawl 7 rotates clockwise, so disengaging from arm 5, which is still maintained against contact 9 since pawl 3 rests on the surface of the moving film 12. It enters the next perforation 4 on aligning with it, so that the position of Fig. 1 is reached again and the motor is braked and the film transport stopped. In the arrangement of Fig. 5 the indicia are in the form of a conductive stripe 16, having an additional coated area 17 and an uncoated area 15. A series of contacts 3<SP>1</SP>, 6<SP>1</SP>, 9<SP>1</SP> and 21 are arranged so that the areas 15 and 17 act as means for controlling the motor to act in the same way as in the Fig. 1 arrangement.