Abstract: A video signal input-output circuit and a recording-reproduction apparatus in which a digitally compressed video signal input in packet form can be recorded and reproduced efficiently and in stable fashion. In this apparatus, a clock reference is detected from a packet signal containing the clock reference and a digitally compressed video signal, a time stamp for a packet is generated using a clock signal in phase with the clock reference and added to the particular packet, and the packet signals with the time stamp added thereto are recorded closely to each other in a data storage element such as a magnetic recording medium. At playback, the packet interval is output by being restored to the original length on the basis of the time stamp added to the packet in store.

Abstract: An apparatus and method for transmitting and receiving digital information includes a transmitting part for transmitting digital video information and digital audio information and receiving part for receiving digital video information and digital audio information. The transmitting part includes a first compressor for digital video information, a second compressor for digital audio information, a parity signal adder, a modulator, and a transmitter. The receiving part includes a receiver which receives digital information which is digital video information bit-compressed by a first compression system plus digital audio information bit-compressed by a second compression system, and to which has been added a parity signal for error detecting, phase-modulated and transmitted to a transmission path; a demodulator; an error detector, a first expander which bit-expands video information, and a second expander which bit-expands audio information.

Abstract: A video signal input-output circuit and a recording-reproduction apparatus in which a digitally compressed video signal input in packet form can be recorded and reproduced efficiently and in stable fashion. In this apparatus, a clock reference is detected from a packet signal containing the clock reference and a digitally compressed video signal, a time stamp for a packet is generated using a clock signal in phase with the clock reference and added to the particular packet, and the packet signals with the time stamp added thereto are recorded closely to each other in a data storage element such as a magnetic recording medium. At playback, the packet interval is output by being restored to the original length on the basis of the time stamp added to the packet in store.

Abstract: A method and apparatus is provided for receiving and/or reproducing a digital signal, capable of efficiently recording a compressed, packeted digital signal and inhibiting a copy thereof. An input packet signal is added with a time stamp indicating a relative time of an arrival of the packet, and the packet signals of digital information with the added time stamps are recorded at reduced intervals therebetween. In reproducing, a packet interval adjusting circuit restores the original packet intervals in accordance with the time stamps, and then a time stamp change circuit changes at least one bit of the time stamp and thereafter outputs the digital information.

Abstract: An apparatus and method for transmitting and receiving digital information includes a transmitting part for transmitting digital video information and digital audio information and receiving part for receiving digital video information and digital audio information. The transmitting part includes a first compressor for digital video information, a second compressor for digital audio information, a parity signal adder, a modulator, and a transmitter. The receiving part includes a receiver which receives digital information which is digital video information bit-compressed by a first compression system plus digital audio information bit-compressed by a second compression system, and to which has been added a parity signal for error detecting, phase-modulated and transmitted to a transmission path; a demodulator; an error detector, a first expander which bit-expands video information, and a second expander which bit-expands audio information.

Abstract: A digital information transmitting, receiving and/or recording/reproducing system, provided with the digital information transmitting apparatus for transmitting the digital information to a transmission path, a receiving apparatus for receiving the transmitted digital information and a recording/reproducing apparatus for the recording received digital information to a recording media and reproducing therefrom. The apparatus includes a compressor which compresses the digital information, a transmission parity signal adder which adds a transmission parity signal to the output signal of the compressor in order to correct an error occurring in the transmission path, wherein the transmission parity signal is different from a record parity signal to be added at the recording apparatus and a transmitter which transmits the transmission parity signal added compressed digital information added by the transmission parity signal adder to the transmission path.

Abstract: A DC-DC converter of low ripple voltages which has a bi-directional power conversion means between an input power source and a smoothing capacitor and can quickly change the output voltage independently of the load. Said DC-DC converter comprises a main circuit of a non-insulated step-down DC-DC converter comprising at least two semiconductor elements, a DC reactor, and a smoothing capacitor, means for generating a variable reference voltage, means for comparing a reference voltage generated by said reference voltage generating means by the output voltage and outputting differential voltage information, means for generating a signal to be applied to the control terminals of said semiconductor element according to said differential voltage information, and means for discriminating the direction of a current flowing through said DC reactor.

Abstract: An object of the present invention is to provide a digital signal recording method and a digital signal recording apparatus, capable of readily producing a signal used to reproduce in a trick play mode from a digital compression video signal. The above-described object of the present invention may be achieved by such a digital video signal recording method for recording a first compression frame signal compressed without using a correlation between frames, and a digital compression video signal having preselected bytes of a packet format constituted by a second compression frame signal compressed with using the correlation between the frames, in which a third signal made of a packet containing the first compression frame signal is produced, and then is recorded in combination with the packet of the digital compression signal.

Abstract: An object of the present invention is to provide a digital signal recording method and a digital signal recording apparatus, capable of readily producing a signal used to reproduce in a trick play mode from a digital compression video signal. The above-described object of the present invention may be achieved by such a digital video signal recording method for recording a first compression frame signal compressed without using a correlation between frames, and a digital compression video signal having preselected bytes of a packet format constituted by a second compression frame signal compressed with using the correlation between the frames, in which a third signal made of a packet containing the first compression frame signal is produced, and then is recorded in combination with the packet of the digital compression signal.

Abstract: A communication system has an analog signal broadcasting station for transmitting an analog signal, a digital signal broadcasting station for transmitting a digital signal and a receiving unit for receiving the analog signal from the analog signal broadcasting station and the digital signal from the digital signal broadcasting station. The receiving unit has a recording and reproducing unit for selectively recording one of received analog and digital signals. The recording and reproducing unit has heads for analog signal each having a predetermined azimuth angle and operative to record an analog signal and heads for digital signal each having an azimuth angle larger than that of the analog signal head and operative to record a digital signal, and performs selective recording and reproduction of the analog signal and the digital signal on and from a recording medium.

Abstract: A digital information transmitting, receiving and/or recording/reproducing system, provided with the digital information transmitting apparatus for transmitting the digital information to a transmission path, a receiving apparatus for receiving the transmitted digital information and a recording/reproducing apparatus for the recording received digital information to a recording media and reproducing therefrom. The apparatus includes a compressor which compresses the digital information, a transmission parity signal adder which adds a transmission parity signal to the output signal of the compressor in order to correct an error occurring in the transmission path, wherein the transmission parity signal is different from a record parity signal to be added at the recording apparatus and a transmitter which transmits the transmission parity signal added compressed digital information added by the transmission parity signal adder to the transmission path.

Abstract: A digital information transmitting apparatus includes a first bit-compressor for bit-compressing a digital video information by a system of discrete cosine transform and a second bit-compressor for bit-compressing a digital audio information by a different system from the system of the first bit-compressor. A parity signal adder is provided for adding a parity signal to the bit-compressed digital video information from the first bit-compressor and the bit-compressed digital audio information from the second bit-compressor, in order to correct an error which occurs in a transmission path. A modulator is provided for phase-modulating the bit-compressed digital video information and the bit-compressed audio information, to which the parity signal has been added by the parity signal adder, and a transmitter ig provided for transmitting the modulated and parity signal added bit-compressed digital video information and bit-compressed digital audio information from the modulator, to the transmission path.

Abstract: A method and apparatus is provided for receiving and/or reproducing a digital signal, capable of efficiently recording a compressed, packeted digital signal and inhibiting a copy thereof. An input packet signal is added with a time stamp indicating a relative time of an arrival of the packet, and the packet signals of digital information with the added time stamps are recorded at reduced intervals therebetween. In reproducing, a packet interval adjusting circuit restores the original packet intervals in accordance with the time stamps, and then a time stamp change circuit changes at least one bit of the time stamp and thereafter outputs the digital information.

Abstract: A digital information transmitting, receiving and/or recording/reproducing system, provided with the digital information transmitting apparatus for transmitting the digital information to a transmission path, a receiving apparatus for receiving the transmitted digital information and a recording/reproducing apparatus for the recording received digital information to a recording media and reproducing therefrom. The apparatus includes a compressor which compresses the digital information, a transmission parity signal adder which adds a transmission parity signal to the output signal of the compressor in order to correct an error occurring in the transmission path, wherein the transmission parity signal is different from a record parity signal to be added at the recording apparatus and a transmitter which transmits the transmission parity signal added compressed digital information added by the transmission parity signal adder to the transmission path.

Abstract: A billing system for use in a chargeable program broadcasting is capable of reliably billing a subscriber for program reception while preventing unauthorized reception thereof. A receiving terminal includes a primary terminal 100 and a secondary terminal 150. The primary terminal 100 receives a compressed video signal and confirms by an error checker 113 thereof whether there is a transmission error and bills, by a billing device 114 thereof, the receiving subscriber on the basis of an error information and a program information, etc., separated from the video signal by a separation circuit 112. The compressed video data is time-axis multiplexed with a terminal identifying code and a key signal and transmitted to the secondary terminal 150. In the secondary terminal 150, a bill for the subscriber is confirmed by the terminal identifying code and the compressed data is decoded by a decoder circuit 166 thereof.

Abstract: Method and apparatus for recording and reproducing a digital signal, by which time information specifying to each packet an interval relative to the adjacent packet is added to a digital signal of a format in which packets of a fixed data length are arranged at unfixed intervals, the digital signal added with time information is recorded on a recording medium, a digital signal added with the above-mentioned time information is reproduced from the recording medium, and the digital signal is output in such a manner that the packets of the reproduced digital signal are arranged at intervals as same as recording intervals on the basis of the time information.

Abstract: A method and apparatus is provided for receiving and/or reproducing a digital signal, capable of efficiently recording a compressed, packeted digital signal and inhibiting a copy thereof. An input packet signal is added with a time stamp indicating a relative time of an arrival of the packet, and the packet signals of digital information with the added time stamps are recorded at reduced intervals therebetween. In reproducing, a packet interval adjusting circuit restores the original packet intervals in accordance with the time stamps, and then a time stamp change circuit changes at least one bit of the time stamp and thereafter outputs the digital information.

Abstract: A digital information recording/reproducing apparatus and method thereof including a parity signal adder which receives error corrected compressed information which has been corrected based upon a first parity signal added to the compressed information and in which the parity signal adder adds a second parity signal to the compressed information which is different from the first parity signal.

Abstract: Method and apparatus for recording and reproducing a digital signal, by which time information specifying to each packet an interval relative to the adjacent packet is added to a digital signal of a format in which packets of a fixed data length are arranged at unfixed intervals, the digital signal added with time information is recorded on a recording medium, a digital signal added with the above-mentioned time information is reproduced from the recording medium, and the digital signal is output in such a manner that the packets of the reproduced digital signal are arranged at intervals as same as recording intervals on the basis of the time information.

Abstract: A video signal input-output circuit and a recording-reproduction apparatus in which a digitally compressed video signal input in packet form can be recorded and reproduced efficiently and in stable fashion. In this apparatus, a clock reference is detected from a packet signal containing the clock reference and a digitally compressed video signal, a time stamp for a packet is generated using a clock signal in phase with the clock reference and added to the particular packet, and the packet signals with the time stamp added thereto are recorded closely to each other in a data storage element such as a magnetic recording medium. At playback, the packet interval is output by being restored to the original length on the basis of the time stamp added to the packet in store.