Motor drive system for camera
First Claim
1. A motor drive system for a camera, comprising a reversible electric motor, a drive shaft for film advancement, means responsive to operation of said motor in one direction for turning said shaft from an initial position in a direction to advance film in said camera and responsive to subsequent operation of said motor in the opposite direction for turning said shaft back to said initial position, means for energizing said motor to operate in said one direction, and motor torque responsive means including means for detecting the current drawn by said motor for sensing when said film has been advanced to a predetermined extent and for thereupon energizing said motor to operate in said opposite direction.
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Accused Products
Abstract
A motor drive system for a camera, including a reversible motor, means for transmitting the revolutions of the motor to a film advance and shutter charge shaft, a control circuit for selecting the operating condition of the motor including forward revolution, reverse revolution and stop, means for delivering a film advance start signal to the control circuit, and torque detector means for detecting a torque applied to the rotary shaft of the motor indicating completion of the film advance, the control circuit being responsive to the torque detector means to initiate reverse revolution of the motor. The control circuit includes at least one flip-flop circuit, a gate circuit having an input coupled to an output of the flip-flop circuit, and two relays connected with the output terminals of the gate circuit and the flip-flop circuit to control the motor. There is further provided a switch which is responsive to the rotation of the film advance and shutter charge shaft to open when the shaft is in a predetermined position and close in all other positions of the shaft. The switch de-energizes the motor when the operation cycles are completed.
25 Citations
9 Claims
- 1. A motor drive system for a camera, comprising a reversible electric motor, a drive shaft for film advancement, means responsive to operation of said motor in one direction for turning said shaft from an initial position in a direction to advance film in said camera and responsive to subsequent operation of said motor in the opposite direction for turning said shaft back to said initial position, means for energizing said motor to operate in said one direction, and motor torque responsive means including means for detecting the current drawn by said motor for sensing when said film has been advanced to a predetermined extent and for thereupon energizing said motor to operate in said opposite direction.
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3. In a motor drive system for a camera having a shutter charge member, shutter release means, and drive shaft means rotatable in one direction to effect film advance and to move said shutter charge member to charge the shutter and rotatable in the reverse direction to a fixed position to return the shutter charge member to its original position so that the shutter may be released after completion of the film advance and shutter charge, the improvement comprising:
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a. a reversible electric motor, b. means for transmitting the forward or reverse revolutions of the motor to the drive shaft means to rotate said shaft means in said one direction or said reverse direction, respectively, c. means for sensing when film has been advanced to a predetermined extent and for thereupon producing a signal, and d. control circuit means for controlling the motor in order to rotate said drive shaft means in said one direction after shutter release, thus effecting film advance and shutter charge, and to rotate said drive shaft means in the reverse direction in response to said signal and thus return said drive shaft means to said fixed position. - View Dependent Claims (4, 5, 6, 7, 8, 9)
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Specification