Abstract: A system stores and reads out a musical tone signal.

Abstract: A tape reproducing system selectively reproduces programs recorded on a recording tape wound on supply and takeup reels and drives the reels at selected fast forward and rewind speeds so that the rotation speed of said reels varies nonlinearly as a function of tape diameter wound on one of said reels. To detect inter-program pauses between programs to replay the recorded programs, the duration of each sensed pause is detected. A memory stores a set of data so each datum of the set represents tape speed as a function of the varying speed of one of the reels. The stored data are read out of the memory in response to the detected rotational speed of one reel. The detected duration is corrected in response to data readout of the memory. The corrected duration is compared with a reference value to generate a control signal for replaying the recorded programs at a playback speed.

Abstract: An automatic skipping control circuit includes a voltage controlled, variable frequency filter having a passband frequency variable in accordance with the voltage of a frequency control signal applied thereto. This filter is responsive to an output signal from a transducer head representative of materials recorded in a tape where a skip-mark signal is recorded in selected portions. The filter is normally tuned to the frequency of the skip mark signal when the tape is transported at normal playing speed. Upon the leading edge of a skip-mark recorded portion reaching the transducer head, the filter provides an output signal which causes the tape to be driven in the fast-forward mode, resulting in an increase in the frequency of the skip-mark signal detected by the transducer head. The frequency control signal is generated during this fast-forward mode to vary the passband frequency of the filter to correspond to the increased frequency of the detected skip-mark signal.

Abstract: A pickup arm is equipped with a photo sensor assembly for detecting non-recorded portions on a disk. The sensor is located in such a position that horizontal distance between the stylus tip and the detecting point of the sensor measured in the direction of the radius of the turntable is substantially constant throughout the possible rotational angle of the arm. The rotational angle of the arm is measured and is modified by a given angle corresponding to the above mentioned distance. When this distance deviates from a standard value on replacement of the same with another, the variation may be readily corrected by manipulating a potentiometer. Prior to performing an automatic playback, the disk is scanned by the sensor and signals indicative of the arm angles corresponding to the non-recorded portions are stored.

Abstract: A tone arm control system includes first and second manually operated keys for providing input signals to a control circuit. The control circuit detects which one of the keys is operated and drives a vertical motor in the tone-arm upward direction and subsequently drives a horizontal motor in a tone-arm horizontal direction depending on which one of the keys is detected as being operated. The control circuit includes a counter which starts counting clock pulses to detect when a predetermined count is reached. During the predetermined count period the horizontal motor is energized at a low voltage to move the tone arm at a relatively low speed. When the clock count exceeds the predetermined value the speed of the tone arm is increased to allow it to speedily approach a desired position located relatively remote from the tone arm.

Abstract: A record disc playing apparatus comprises a horizontal drive motor for imparting a horizontal rotational force to a tone arm an address signal generating device for generating an address signal corresponding to a horizontal rotational angle position of the tone arm and a control device including a memory device for storing the magnitude of an inside force to be produced on the tone arm in correspondence with the horizontal rotational angle position of the tone arm. The address signal generating device supplies the generated address signal to the control device. The control device reads out the magnitude of the inside force from the memory device corresponding to the supplied address signal, produces a signal for cancelling the inside force at the rotational angle position of the tone arm corresponding to the read out magnitude of the inside force and supplies the same to the horizontal drive motor.

Abstract: In order to compensate for differences in magnetic properties of recording tapes, a first and second audio test signals of different frequencies are generated by a variable frequency test signal source, recorded on a magnetic tape and reproduced to represent the magnetic properties of the tape at the different frequencies. The reproduced first test signal is stored in a microcomputer for comparison with the level of the subsequently reproduced second test signal to detect the difference therebetween for making an adjustment of the level of the second test signal in accordance with the detected difference through the use of a level adjusting device. The latter is thereafter held adjusted to the value at which the two test signals have an equal level of reproduction.

Abstract: An automatic attenuation circuit comprises a variable loss attenuation circuit that drives circuitry for detecting the level of the output signal of the variable loss attenuation circuit. The level detector drives a periodically reset integrator, which in turn feeds a signal to a comparator, also responsive to a reference. A control circuit responsive to the output signal of the comparator controls the attenuation factor of the variable loss attenuation circuit. The control circuit, which may be a microcomputer, is so programmed that the attenuation factor of the variable loss attenuation circuit is stepwisely increased until the level of the output signal of the variable loss attenuation circuit becomes equal to or below a predetermined level.

Abstract: An automatic recording level controlling circuit comprises an audio test signal oscillator, a variable loss attenuation circuit, level detecting circuitry and a control circuit for controlling the attenuation factor of the variable loss attenuation circuit in accordance with the output of the level detecting circuitry. The level of a reproduced signal corresponding to the test signal is detected to see the deviation from a reference level so that the attenuation factor of the variable loss attenuation circuit is controlled in such a manner that the level of the reproduced signal is as close to the reference level as possible.

Abstract: An automatic bias level setting circuit for tape recorders includes a variable loss attenuator for stepwisely increasing the level of a high frequency bias signal which is superposed on a constant amplitude audio test signal. The recorded signal is detected by means of an envelope detector coupled to the playback head and fed into a resettable integrator for integrating the input signal in response to each stepwise variation of the signal to generate a series of sawtooth waves. The output of the integrator is coupled to a maximum peak detector to detect the maximum peak point of the recorded test signal to determine an optimum bias level in relation to the detected peak point.

Abstract: A multichannel record disc reproducing system and apparatus comprises a phase-locked loop for demodulating an angle-modulated wave signal in a multiplexed signal picked up from a multichannel record disc. A synchronous detector compares the phases of the angle-modulated wave signal and an output signal of a voltage-controlled oscillator in the phase-locked loop. The detector produces an output signal when there is a noise component in the angle-modulated wave signal. A circuit, controlled by the output of the synchronous detector, provides a demodulated output signal having at least one attenuated frequency band, in which a noise component is greatly reduced.