Abstract: A method of producing a tracking control signal in a rotary head type magnetic recording and reproducing apparatus and a rotary head type magnetic recording and reproducing apparatus capable of a proper tracking by the use of the tracking control signal.

Abstract: A digital signal reproducing apparatus in which the frequency of a basic clock signal generated from a clock generator having a fixed oscillation frequency is divided to produce a clock signal used for processing a digital signal, and, when the transmission speed of the digital signal is changed, the frequency division ratio is also changed to produce a clock signal synchronous with the digital signal transmitted at the changed transmission speed.

Abstract: An integration type D/A and A/D converter having improved linearity and low power consumption. Logic circuits such as ECL counters consuming a major part of power of the D/A and A/D converters are realized through CMOS process. Current source circuits, current switch circuit and comparator circuit of the integration type A/D converter are realized in IC through bipolar process ensuring high accuracy and low noise. Logic parts such as counter is realized through CMOS process.

Abstract: In a recording operation by a rotary head type PCM recording/reproducing apparatus including at least two magnetic heads, the odd-numbered sample data and the even-numbered sample data are discriminatively extracted and stored. The stored data corresponding to an amount of data outputted from the A/D converter within a predetermined time is selectively read out and supplied to the two heads to thereby record the data in such a manner that the odd-numbered data and the even-numbered data are recorded separately on a track basis or alternatively recorded separately on a preceding half and a succeeding half of each track. The error detecting and correcting code is prepared on the basis of the data to be recorded in each track. In reproduction of the recorded data, upon detection of a drop-out of the data from one of the two heads, the drop-out data is corrected through interpolation procedure to thereby reconstitute the original analog signal.

Abstract: This invention relates to an error correction upon reproduction of digital signals. The error correction is performed by decoding code words such as cross-interleaved Reed Solomon codes, in which first code blocks are formed by a plurality of information words which are in the first arrangement state and a plurality of first check words which are produced by codes associated with the plurality of information words with a Hamming distance of d.sub.1, and second code blocks are formed by a plurality of information words and a plurality of first check words which are in the second arrangement state and which consist of the said plurality of information words and the said plurality of first check words which are respectively included in the different first code blocks, and by a plurality of second check words which are produced by codes associated with the plurality of information words and the plurality of first check words with a Hamming distance of d.sub.2.

Abstract: A method of transmitting a digital signal in the form of successive signal frames containing codes for detecting and correcting errors of the digital signal for reducing degradation in the quality of the reproduced sound due to generation of the code errors in a digitized audio signal transmission system. An analog signal such as an audio signal is sampled and subjected to A/D conversion. The sample word thus obtained is divided into a plurality of symbol elements. Parity words for detecting and correcting code errors are added to every group of a predetermined number of the information symbols through an interleave procedure before being transmitted.

Abstract: A digital signal recording/reproducing apparatus capable of recording and reproducing digital signals having differences in respect to sampling frequency thereof and the number of quantization bits per sample by means of a common circuit arrangement includes means for varying revolution speed of rotating heads for recording and reproduction or traveling speed of a recording medium as a function of different sampling frequencies. A signal processing circuit for processing the digital signals so as to be suited for the recording on the recording medium is controlled by a clock signal of which frequency is changed in dependence on the different sampling frequencies. The signal processing circuit is arranged so that PCM data contained in a frame is constituted by a number of bits which is equal to a common multiple of the different quantization bit numbers and added with a common frame synchronizing signal and common error detection and correction codes to thereby prepare the PCM signal of the frame arrangement.

Abstract: In a magnetic recording and reproducing apparatus of 2-head helical scan type, an overlapping portion is formed at one end of each video track on a magnetic tape, and a PCM audio signal is recorded on this overlapping portion. Video/audio selective switching circuits are disposed on the input or output side of video and audio recording amplifiers, and video/audio selective switching circuits and video/audio playback equalizer circuits are disposed on the output side of video and audio playback amplifiers. Each of the heads acts as both of a video head and an audio head.

Abstract: A stereo demodulation system for an FM stereo broadcast receiver having frequency dividing means receiving the output of the voltage controlled oscillator in the phase locked loop and producing the first and the second switching signals which are supplied to the first and the second switch and decoder circuit for switching and decoding the stereo composite signal, wherein said first and second switching signals are produced with the fixed phase relationship therebetween.

Abstract: An integration type D/A and A/D converter having improved linearity and low power consumption. Logic circuits such as ECL counters consuming a major part of power of the D/A and A/D converters are realized through CMOS process. Current source circuits, current switch circuit and comparator circuit of the integration type A/D converter are realized in IC through bipolar process ensuring high accuracy and low noise. Logic parts such as counter is realized through CMOS process.