Abstract: An optical pickup position control device according to the present invention automatically adjusts tracking with precision and in a short time. Two deviation signals, which express deviation of a light beam, projected by a pickup which uses the three-beam method, from a target track of a disk, are digitized by two AD converters. Two high-pass filters extract from the deviation signals AC signals, producing a tracking error signal. Further, two low-pass filters extract from the deviation signals DC signals (offset components). Two other low-pass filters extract from the deviation signals low-band signals containing DC components. Using the various foregoing signals, a control circuit calculates correction values to be applied to two offset correcting circuits and to two gain/balance correcting circuits, and corrections are performed collectively and simultaneously on the basis of these correction values.

Abstract: To reduce a power loss and elongate the service life of a battery in a power supply circuit for a widely variable power-consuming load. In a device with a dry battery and a rechargeable battery, the rechargeable battery supplies the power while its output voltage is higher than a 3.4V-voltage increased voltage by a voltage increasing circuit. When the output voltage of the rechargeable battery decreases lower than 3.4V, the voltage increasing circuit operates and the dry battery works as a power supply. The power voltage increased by the voltage increasing circuit through a choke coil is fed to respective voltage decreasing circuits. The current is also fed to recharge the rechargeable battery when the output voltage of the choke coil is higher than the output voltage of the rechargeable battery. When the load is increased by the operation of a pickup, the power stored in the rechargeable battery together with the power from the dry battery after increased to 3.

Abstract: An optical pickup position control device according to the present invention automatically adjusts tracking with precision and in a short time. Two deviation signals, which express deviation of a light beam, projected by a pickup which uses the three-beam method, from a target track of a disk, are digitized by two AD converters. Two high-pass filters extract from the deviation signals AC signals, producing a tracking error signal. Further, two low-pass filters extract from the deviation signals DC signals (offset components). Two other low-pass filters extract from the deviation signals low-band signals containing DC components. Using the various foregoing signals, a control circuit calculates correction values to be applied to two offset correcting circuits and to two gain/balance correcting circuits, and corrections are performed collectively and simultaneously on the basis of these correction values.

Abstract: An optical pickup position control device according to the present invention automatically adjusts tracking with precision and in a short time. Two deviation signals, which express deviation of a light beam, projected by a pickup which uses the three-beam method, from a target track of a disk, are digitized by two AD converters. Two high-pass filters extract from the deviation signals AC signals, producing a tracking error signal. Further, two low-pass filters extract from the deviation signals DC signals (offset components). Two other low-pass filters extract from the deviation signals low-band signals containing DC components. Using the various foregoing signals, a control circuit calculates correction values to be applied to two offset correcting circuits and to two gain/balance correcting circuits, and corrections are performed collectively and simultaneously on the basis of these correction values.

Abstract: A digital control type volume control circuit is disclosed herein which includes a multivibrator, an UP key, a DOWN key, a pair of binary UP/DOWN counters, a 4-to-16 line decoder, an encoder and an attenuator. The multivibrator is connected to the UP and DOWN keys to furnish pulses to the counter via an actuated one of the UP and DOWN keys. The counter counts the number of the pulses via the UP and DOWN key, with the counter being indicative of the length of actuation of the UP or DOWN key. The encoder responsive to the count of the counter output count provides an output for the attenuator having a plurality of resistors of different resistances for determination as to the amount of attenuation.

Abstract: A tone control circuit for use in audio equipments includes an attenuating high pass filter (typically, a CR filter), an attenuating low pass filter, a boosting high pass filter, a boosting low pass filter and at least an operational amplifier for tone control. The high pass filters extract a treble component from an audio input signal for emphasizing or attenuating treble response, whereas the low pass filter extract a bass component of the audio input signal for emphasizing or attenuating bass response. The mid-range component of the audio input signal prevented from entering the filters by virtue of a bypass circuit interposed between a source of the audio input signal and the operational amplifier.