Patent GB-1478399-A (GB)
Title: Motor driving device for a camera
IPC: G03B17/00
Filed: 1974-12-20
Abstract: 1478399 Cameras KONISHIROKU PHOTO INDUSTRY CO Ltd 20 Dec 1974 [28 Dec 1973] 55289/74 Heading G2A A motor driving device for a camera selectively operable in single frame or successive photographing modes comprises a motor M for releasing a shutter to effect exposure and for winding a film, a relay RL2 controlling a switch RL2-1 for switching the motor on and off, a change-over switch SW2 for connecting RL2 alternatively to a film winding control circuit when shutter release is completed and to a parallel shutter release control circuit when film winding is completed, the winding control circuit including a transistor TR2 (or a thyrister D4) Fig. 3 (not shown), and a normally closed switch SW5', the release control circuit being operative to release the shutter after a predetermined time interval and including a normally open release switch SW5 and a mode switch SW4, shown in the single shot position, in parallel with SW5' for selecting single shot or successive photographing modes, the arrangement being such that in the single shot mode, with SW4 in the position shown, depression of a release button to open SW5' and close SW5 to render TR2 non-conductive and shutter release is effected, and when the release button is released TR2 is conductive and winding is effected, and in the successive photographing mode SW4 is moved from the position shown and when the release button is depressed, shutter release and winding are alternately effected as SW2 switches alternately between the control circuits, TR2 being continuously conductive independently of SW5 and SW5', and the mode continuing until the release button is released. The mode switch SW4 operates in conjunction with a further switch SW3 connected with a second transistor TRI controlling the interval of shutter release by means of a timing circuit D1, VRI, R1, C1 connected through a switching circuit SC to TR1. In use, starting from the condition shown in Fig. 1 with SW3, SW4 in the single shot position and the film wound, switch SW9 is closed, release button is pressed to close SW5, open SW5', and turn off TR2, hence RL2 operates to move RL2-1 to position h. Thus M starts, exposure is initiated by conventional release mechanism, and SW10 is opened by a conventional diaphragm mechanism. RL2 becomes inoperative after a period determined by the time constant circuit, RL2-1 moves to a to short-circuit M which is braked and stopped. As SW10 opens, SW2 moves to B. Exposure is effected with SW2 at A, and film is wound with SW2 at B. If release button remains pressed, SW5' stays open, TR2 is non-conductive, RL2 is inoperative, and M remains stopped. If the release button is released, SW5' closes, TR2 conducts, RL2 causes operation of M to wind film. When one frame is wound, SW2 moves to A, RL2 becomes inoperative, M stops and the shutter is ready for the next frame. For successive photographing SW3 and SW4 are moved to contacts C1, C2, thus the short-circuit of TR1 is broken. Also the base of TR2 remains connected to the -Ve line 2 via R5 and SW4 regardless of the position of SW5', i.e. position of release button. When SC1 is operated, i.e. for a fixed time determined by time constants set by Cl and R1+VR1, current flows through R4 to render TR1 conductive for release operation. When the release button is pressed, SW5 closes, SC1 becomes operative, TRI conducts, RL2 operates, M starts and exposure is effected as for single shot operation. After exposure SW2 moves to B, TR2 conducts, through R5 and SW4, RL2 remains inoperative, film is wound, then SW2 moves to A. As SW2 moves to A, SW1 closes briefly in conventional manner to allow C1 to discharge. SC I becomes operative, TR1 becomes non-conductive, M stops so that release is not immediately effected even if SW5 is kept closed. After a period determined by the time constant circuit, SC1 is actuated, TR1 conducts and M operates to effect a further exposure and the cycle is continuously repeated. Other, modified control circuits are described Figs. 2, 3 (not shown). In a further modified circuit, Fig. 4, switch SW5' of Fig. 1 is replaced by a relay switch RL1-2 operated by a relay RL1 which is actuated by closing SW5. Also. a remote control switch SWR is included in parallel with SW5.