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: 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 FM multiplex broadcasting receiving apparatus includes a decoder for decoding multiplexed data from the received multiplex broadcasting, a CPU for writing the decoded content to RAM, a display unit for displaying the content stored in the RAM, an auto-mode switch for switching method of display of the information displayed on the display unit, and an audio signal reproducing circuit for selectively reproducing only the audio information from FM multiplex broadcasting. When the auto-mode switch is off, display corresponding to the audio sound reproduced by the audio signal reproducing circuit is given on the display unit. If the auto-mode switch is on, the display unit successively displays the contents of the information stored in the RAM, regardless of the audio sound reproduced by the audio signal reproducing circuit. Namely, by turning on the auto-mode switch, the user can see all the information stored, without any operation.

Abstract: The invention is directed to simultaneously implement display by using the first and second liquid crystal display sections. While a voltage (1/2 V.sub.L) which is a half of a drive voltage V.sub.L supplied from the second drive power supply by the second liquid crystal driver is taken as a virtual ground, a voltage (1/4 V.sub.L) resulting from positively and negatively dividing by 4 the drive voltage V.sub.L is applied to each of electrodes of the second liquid crystal display section defined in the liquid crystal display panel. In a selected waveform, by applying a voltage which exceeds the saturation voltage of liquid crystals, to selected portions of the waveform, the liquid crystals are turned on. In a non-selected waveform, such a voltage is not applied. In the second liquid crystal display section, direct current component of the waveform of a signal supplied by the second liquid crystal driver is cut off by the direct current cutoff circuit. A bias voltage (1/2 V.sub.