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US 4,039,195 AGranted
Pickup arm driving device in linear tracking pickup apparatus
AssigneeNippon Gakki Seizo Kabushiki Kaisha
InventorMotoi Iyeta
Life of this patent
Estimating the term…
Abstract
A pickup arm driving device in a linear tracking apparatus. The offset angle of the pickup arm is photoelectrically detected to produce a corresponding offset angle signal for driving a motor to move the pickup arm. Completion of the reproduction of sound from a disc causes a groove end detection signal which operates an electromagnetic lifter causing upward swinging of the pickup arm and a quick return of the pickup arm to an arm rest position.
Claims18
A pickup arm driving device in a linear tracking pickup apparatus with a pickup arm traceable on a disc, comprising:
- support means including a movable supporting mechanism for supporting the pickup arm for vertical as well as horizontal movements and permitting the pickup arm to make linear travel radially of a disc in a horizontal direction;
- a motor designed so that its rotation speed and direction of rotation are determined by the value and the polarity of the voltage applied;
- a motive power transmitting means for converting the rotation force of said motor to a linear movement force and transmitting the latter force to said movable supporting mechanism;
- an offset angle detector for detecting a horizontal offset angle of the pickup arm;
- an offset signal generating circuit associated with said offset angle detector for generating an offset signal having a variable value and polarity corresponding to the variable magnitude and direction of the offset angle detected;
- an amplifier for receiving, as an input thereof, said offset signal and for driving said motor, by the output of this amplifier, to rotate in a direction corresponding to the direction of movement of said movable supporting mechanism in which the offset angle decreases;
- a signal groove end detecting circuit for detecting the face that the pickup arm has arrived at the end position of the signal-carrying groove of the disc by detecting when the said value of said offset signal exceeds a predetermined level of magnitude for generating a groove end detection signal;
- a finished position detecting means for detecting the arrival of the whole pickup arm into a required range of distance from the center of the disc to produce a finish position detection signal, and
- means coupling said position detecting means to said signal groove end detecting circuit for preventing generation of a signal groove end detection signal in the absence of a said finish position detection signal from said position detecting means.
6 more elements
A pickup arm driving device in a linear tracking pickup apparatus with a pickup arm traceable on a disc, comprising:
- support means including a movable supporting mechanism for supporting the pickup arm for vertical as well as horizontal movements and permitting the pickup arm to make linear travel radially of a disc in a horizontal direction;
- a motor designed so that its rotation speed and direction of rotation are determined by the value and the polarity of the voltage applied;
- a motive power transmitting means for converting the rotation force of said motor to a linear movement force and transmitting the latter force to said movable supporting mechanism;
- an offset angle detector for detecting a horizontal offset angle of the pickup arm;
- an offset signal generating circuit associated with said offset angle detector for generating an offset signal having a value and polarity corresponding to the magnitude and direction of the offset angle detected;
- an amplifier for receiving, as an input thereof, said offset signal and for driving said motor, by the output of this amplifier, to rotate in a direction corresponding to the direction of movement of said movable supporting mechanism in which the offset angle decreases;
- a signal groove end detecting circuit for detecting the fact that the pickup arm has arrived at the end position of the signal-carrying groove of the disc by detecting when the said value of said offset signal exceeds a predetermined level of magnitude for generating a groove end detection signal;
- an electrically-controlled arm lifter provided in said movable supporting mechanism for moving the pickup arm to and away from the disc;
- and
- a lifter control circuit coupled to said arm lifter and to said signal groove end detecting circuit to receive said groove end detection signal to drive said arm lifter in a direction that the pickup arm moves away from the surface of the disc.
7 more elements
A pickup arm driving device in a linear tracking pickup apparatus with a pickup arm traceable on a disc, comprising:
- support means including a movable supporting mechanism for supporting the pickup arm for vertical as well as horizontal movements and permitting the pickup arm to make linear travel radially of a disc in a horizontal direction;
- a motor designed so that its rotation speed and direction of rotation are determined by the value and the polarity of the voltage applied;
- a motive power transmitting means for converting the rotation force of said motor to a linear movement force and transmitting the latter force to said movable supporting mechanism;
- an offset angle detector for detecting a horizontal offset angle of the pickup arm;
- an offset signal generating circuit associated with said offset angle detector for generating an offset signal having a value and polarity corresponding to the magnitude and direction of the offset angle detected;
- an amplifier for receiving, as an input thereof, said offset signal and for driving said motor, by the output of this amplifier, to rotate in a direction corresponding to the direction of movement of said movable supporting mechanism in which the offset angle decreases;
- an electrically driven arm lifter provided in said movable supporting mechanism for moving the pickup arm to and away from the disc;
- a lifter control circuit;
- a manual control signal generating circuit for generating, by manual operation, a lifter control signal and a manual control feed signal,
- said lifter control circuit, upon its receipt of said lifter control signal, driving the arm lifter, whereby the pickup arm is moved away from the disc, said amplifier, upon its receipt of said manual control feed signal, driving by its output said motor at a rotation speed and in a direction of rotation corresponding to the value and the polarity, respectively, of said manual control feed signal;
- and
- a signal-carrying groove end detecting circuit for detecting the arrival of the pickup arm at the signal-carrying groove end of the disc by detecting when the said value of said offset signal exceeds a predetermined level of magnitude for generating a groove end detection signal,
- said lifter control circuit, upon its receipt of said groove end detection signal via said manual-automatic mode changeover circuits, driving said arm lifter.
10 more elements
A pickup arm driving device in a linear tracking pickup apparatus with a pickup arm traceable on a disc, comprising:
- support means including a movable supporting mechanism for supporting the pickup arm for vertical as well as horizontal movements and permitting the pickup arm to make linear travel radially of a disc in a horizontal direction;
- a motor designed so that its rotation speed and direction of rotation are determined by the value and the polarity of the voltage applied;
- a motive power transmitting means for converting the rotation force of said motor to a linear movement force and transmitting the latter force to said movable supporting mechanism;
- an offset angle detector for detecting a horizontal offset angle of the pickup arm;
- an offset signal generating circuit associated with said offset angle detector for generating an offset signal having a value and polarity corresponding to the magnitude and direction of the offset angle detected;
- an amplifier for receiving, as an input thereof, said offset signal and for driving said motor, by the output of this amplifier, to rotate in a direction corresponding to the direction of movement of said movable supporting mechanism in which the offset angle decreases;
- a signal groove end detecting circuit for detecting the fact that the pickup arm has arrived at the end position of the signal-carrying groove of the disc by detecting when the said value of said offset signal exceeds a predetermined level of magnitude for generating a groove end detection signal;
- an electrically-controlled arm lifter provided in said movable supporting mechanism for moving the pickup arm to and away from the disc;
- a lifter control circuit coupled to said arm lifter and to said signal groove end detecting circuit to receive said groove end detection signal to drive said arm lifter in a direction that the pickup arm moves away from the surface of the disc;
- and
- a position detecting means for detecting the arrival of the pickup arm from the center of the disc into a required range of distance,
- said signal groove end detecting circuit including means for preventing generation of a signal groove detection signal in the absence of a detection signal from said position detecting means;
- said position detecting means comprising a permanent magnet provided on that portion of said movable supporting mechanism which is adapted to move together with the pickup arm, and a magnetically sensitive switch adapted to be closed and opened by the magnetic field of said permanent magnet when the pickup arm is within said required range of distance.
10 more elements
A pickup arm driving device in a linear tracking pickup apparatus with a pickup arm traceable on a disc, comprising:
- support means including a movable supporting mechanism for supporting the pickup arm for vertical as well as horizontal movements and permitting the pickup arm to make linear travel radially of a disc in a horizontal direction;
- a motor designed so that its rotation speed and direction of rotation are determined by the value and the polarity of the voltage applied;
- a motive power transmitting means for converting the rotation force of said motor to a linear movement force and transmitting the latter force to said movable supporting mechanism;
- an offset angle detector for detecting a horizontal offset angle of the pickup arm;
- an offset signal generating circuit associated with said offset angle detector for generating an offset signal having a value and polarity corresponding to the magnitude and direction of the offset angle detected;
- an amplifier for receiving, as an input thereof, said offset signal and for driving said motor, by the output of this amplifier, to rotate in a direction corresponding to the direction of movement of said movable supporting mechanism in which the offset angle decreases;
- an electrically driven arm lifter provided in said movable supporting mechanism for moving the pickup arm to and away from the disc;
- a lifter control circuit;
- a manual control signal generating circuit for generating, by manual operation, a lifter control signal and a manual control feed signal,
- said lifter control circuit, upon its receipt of said lifter control signal, driving the arm lifter, whereby the pickup arm is moved away from the disc, said amplifier, upon its receipt of said manual control feed signal, driving by its output said motor at a rotation speed and in a direction of rotation corresponding to the value and the polarity, respectively, of said manual control feed signal;
- in which said offset angle detector comprises:
- a photo-electricity converting element comprised of:
- a resistor;
- a first and a second lead extending from the opposite ends of said resistor;
- an electroconductive electrode provided to face said resistor and electrically contacting said resistor via a photoconductor having the characteristic that its conductivity increases when exposed to light rays;
- a third lead extending from said electrode,
- a light-emitting source, and
- a slit-carrying plate having a slit for passing therethrough as beam-like light rays the light rays emitting from said light-emitting source and mechanically coupled to the pickup arm for moving in correspondence with the offset angle of the pickup arm,
- the position at which the beam-like light rays having passed through said slit impinge onto the photoconductor of the photo-electricity converting element moving between the opposite ends of said resistor in accordance with the variation of the offset angle, and in which:
- the offset signal generating circuit and said manual control signal generating circuit both are comprised of a common bridge circuit and a direct current voltage source connected to this bridge circuit, said manual control signal generating circuit further comprising a manual-automatic mode changeover circuit,
- said bridge circuit comprising said resistor of said photo-electricity converting element and a manually operable potentiometer having a slider tap,
- the non-balanced output of said bridge circuit which appears in correspondence with that position on said photoconductor of the photo-electricity converting element onto which the beam-like light rays impinge being inputted to said amplifier as said offset signal,
- the non-balanced output of said bridge circuit which appears in correspondence with that position assumed by the slider tap of said potentiometer being inputted to said amplifier as said manual control feed signal,
- said manual-automatic mode changeover circuit generating said lifter control signal when it is set to the manual operation mode.
21 more elements
Dependencies are inferred from the claim text.