Pickup arm driving device in linear tracking pickup apparatus

Claim 2

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.

Claim 3

A pickup arm driving device according to claim 1, further comprising: 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; and 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.

Claim 4

A pickup arm driving device according to claim 1, in which: said offset angle detector comprises an angle-optical converting means for converting any horizontal offset angle of the pickup arm to an optical variation, and a photo electricity converting element for converting the optical variation to an electrical amount.

Claim 5

A pickup arm driving device according to claim 3, in which: said photo-electricity converting element comprises: 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; and a third lead extending from said electrode, and in which: said angle-optical converting means comprises: a light-emitting source; a slit-carrying plate having a slit for passing therethrough as beam-like light rays the light emitting from the light-emitting source and being mechanically coupled to the pickup arm for moving in correspondence with the offset angle of the pickup arm, and in which: the position at which the beam-like light rays which have passed through said slit impinge onto the photoconductr of the photo-electricity converting element moves between the opposite ends of said resistor in accordance with the variation of said offset angle.

Claim 6

A pickup arm driving device according to claim 4, in which: said offset signal generating circuit comprises: a bridge circuit formed with said resistor of said photo-electricity converting element and at least two resistors, and a direct current voltage source coupled to said bridge circuit, and in which: said offset signal is derived from said third lead of the photo-electricity converting element.

Claim 7

A pickup arm driving device according to claim 1, in which: said movable supporting mechanism comprises: a movable frame having rotatable rollers; a supporting mechanism for allowing the pickup arm to freely make horizontal as well as vertical swinging movement, on said movable frame; and guide rails provided in parallel with a radial direction of the disc, said movable frame being supported on said guide rails by said rotatable rollers for free movement radially of the disc, and in which: said motive force transmitting means comprises: pulley provided on one end of said guide rails and rotatable jointly with the rotary shaft of said motor; a second pulley rotatably provided at a position of the other end of said guide rails so as to face said first pulley; and a belt applied between said first and second pulleys and coupled, intermediately thereof, to said movable frame.

Claim 8

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.

Claim 9

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.

Claim 10

A pickup arm driving device according to claim 7, further comprising: a quick return signal generating circuit; a delay circuit; and a reset circuit for generating a reset signal when the pickup arm is at an arm rest position, and arranged so that said quick return signal generating circuit delivers to said amplifier a quick return signal whenever this circuit receives said groove end detection signal delayed by said delay circuit, said quick return signal being an electric signal having a value and a polarity enough for the amplifier to generate an output necessary for rotating said motor at a high speed in a direction in which said movable supporting mechanism is driven to move the pickup arm at a toward the arm rest position at a speed substantially higher than said motor drives said pickup arm supporting mechanism away from said rest position, said quick return signal generating circuit ceasing the generation of said quick return signal upon its receipt of said reset signal, said signal groove end detecting circuit ceasing the generation of said groove end detection signal upon its receipt of said reset signal.

Claim 11

A pickup arm driving device according to claim 7, further comprising: 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 preventing generation of a signal groove detection signal at the absence of a detection signal from said position detecting means.

Claim 12

A pickup arm driving device according to claim 7, in which: the signal which varies in its level in association with said offset signal is an output signal of said amplifier.

Claim 13

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;

Claim 14

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;

Claim 15

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.

Claim 16

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.

Claim 17

A pickup arm driving device according to claim 11, further comprising: a quick return signal generating circuit; a delay circuit; and a reset circuit for generating a reset signal when the pickup arm is at arm rest position, said quick return signal generating circuit, upon its receipt of the groove end detection signal after being delayed by said delay circuit, delivering a quick return signal to said amplifier, said quick return signal being an electrical signal having a value and a polarity enough for said amplifier to generate an output necessary for rotating said motor at a high speed in a direction in which said movable supporting mechanism is driven to move the pickup arm at a high speed toward the arm rest position, said quick return signal generating circuit ceasing the generation of said quick return signal upon its receipt of said reset signal, said signal groove end detecting circuit generating said groove end signal upon its receipt of said reset signal.

Claim 18

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.

Claim 19

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.

Claim 20

A pickup arm driving device according to claim 13 wherein said magnetically sensitive switch is a reed switch.

Claim 21

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.

Claim 22

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.

Claim 23

A pickup arm driving device according to claim 15, further comprising: a signal groove end detecting circuit for detecting the arrival of the pickup arm at the signal-carrying groove end position 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 driving said arm lifter when it receives said groove end detection signal.

Claim 24

A pickup arm driving device according to claim 16, further comprising: a first relay; a delay circuit to which said groove end detection signal is inputted; and a reset circuit for generating a reset signal when the pickup arm is at an arm rest position, the contact of said first relay being connected to said bridge circuit, said relay contact being closed or opened by the delayed output of said delay circuit when the latter circuit receives said groove end detection signal, thereby destroying the balanced state of said bridge circuit, whereby the resulting non-balanced output of said bridge circuit is inputted to said amplifier as a quick return signal, said delay circuit opening or closing said relay contact when it receives said reset signal, whereby said bridge circuit becomes balanced and the generation of said quick return signal ceases, said quick return signal being an electrical signal having a value and a polarity enough for said amplifier to generate an output necessary for causing said motor to make a high speed rotation in a direction in which said movable supporting mechanism is driven to effect a high speed feed of the pickup arm toward the arm rest position.

Claim 25

A pickup arm driving device according to claim 15, in which: said potentiometer has spring means, the slider tap of said potentiometer, when this tap is not manually operated, being held by the spring force of said spring means at a position in which said bridge circuit is balanced when said offset angle is zero.