Sharp Kabushiki Kaisha Corporation

Makoto Adachi

Hiroyoshi Toda

Tadami Tanabe

In a system including the first terminal and the second terminal. A communication method at the first terminal includes the steps of preparing its own device name, detecting a request for connection with the second terminal, rewriting the device name in response to the request, and transmitting the changed device name to the second terminal. A communication method at the second terminal includes the steps of receiving device names from a plurality of first terminals, displaying the device names for the user of the second terminal to recognize a changed device name easier than unchanged device names, and communicating with the first terminal specified by a device name selected by the user.

Communication system, terminal, communication method, and recording medium recording communication method program for selecting terminal of communication party

A video signal recording and reproducing apparatus in accordance with the present invention includes A/D converters, a shuffling circuit and magnetic heads. The A/D converters A/D-convert a luminance signal Y and color difference signals P.sub.B and P.sub.R included in a video signal. The shuffling circuit divides each A/D converted data into first and second channels and further divides the first and second channels into data of a first segment including the color difference signal P.sub.R and data of a second segment including the color difference signal P.sub.B. The data of the first segments of the first and second channels are recorded on a magnetic tape with a spacing of one track by the magnetic heads, data of the second segment of the first channel is recorded by the magnetic head on a portion between the tracks where the first segments are recorded, and data of the second segment of the second channel is recorded on a portion adjacent to the track where the first segment of the second channel is recorded. In a hi-vision VTR, it is possible to prevent an image of improper or poor hues due to differences in characteristics between the channels and enhance a capability of dropout compensation.

Apparatus and method of recording and reproducing video signal

A video signal recording-reproduction device is provided with a recording device for applying time base extension of N-times to an input video signal to form a recording signal and recording the signal on a recording medium by dividing it into a plurality of channels the number of which is given by N or integral multiples of N. The recording device includes a line memory control circuit for shifting a phase of a signal such that the phase shift between adjacent channels is a 1/N horizontal scanning period. The video signal recording-reproduction device is also provided with a reproduction device for forming an output video signal by reproducing a recording signal from each channel and by making a separated sync signal of the recording signal of each channel to coincide with a horizontal synchronizing signal of the input video signal. More specifically, the reproduction device includes an OR circuit which conducts a logical OR operation upon the separated sync signals of the respective signals, each reproduced from each channel. Thereby, the separated sync signal obtained by the logical OR operation coincides with the horizontal synchronizing signal of the input video signal.

Video signal recordding-reproduction apparatus for wide band video

A video signal recording apparatus is provided with first and second channels for transmitting an input video signal. The first channel has a line memory for conducting a 1H delay on data and a time-base-extension line memory for conducting time base extension on the data with the 1H delay. The data subjected to the time base extension undergoes D/A conversion to be an output of the first channel. On the other hand, the second channel does not have a line memory for a 1H delay, and the video signal without delay is subjected to time base extension and undergoes D/A conversion to be an output of the second channel. In the arrangement, odd lines and even lines respectively contained in adjoining two frames in each channel are reversed such that in a certain frame, odd lines of the input video signal are transmitted through the first channel with even lines through the second channel. In the next frame, even lines are transmitted through the first channel with odd lines through the second channel. Thus, influences on the reproduced picture due to the difference of circuit characteristics is averaged and the perception to unevenness of color or brightness is avoided.

Method and apparatus for two-channel recording of video signals

A video signal recording apparatus is provided with first and second channels for transmitting an input video signal. The first channel has a line memory for conducting a 1H delay on data and a time-base-extension line memory for conducting time base extension on the data with the 1H delay. The data subjected to the time base extension undergoes D/A conversion to be an output of the first channel. On the other hand, the second channel does not have a line memory for a 1H delay, and the video signal without delay is subjected, to time base extension and undergoes D/A conversion to be an output of the second channel. In the arrangement, odd lines and even lines respectively contained in adjoining two frames in each channel are reversed such that in a certain frame, odd lines of the input video signal are transmitted through the first channel with even lines through the second channel. In the next frame, even lines are transmitted through the first channel with odd lines through the second channel. Thus, influences on the reproduced picture due to the difference of circuit characteristics is averaged and the perception of unevenness of color or brightness is avoided.

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Nikko, Japan

Makoto Adachi