Mitsubishi Denki Kabushiki Kaisha

Takahiro Nakai

Yoshiko Hatano

Masato Nagasawa

Yoshinobu Ishida

Yoshinori Asamura

Hidetoshi Mishima

Tadashi Kasezawa

Hiroyuki Oohata

Satoshi Kurahashi

Shuji Sotoda

Keiji Hatanaka

A digital video signal record and playback device for recording on a recording medium a digital video signal coded by using a motion compensation prediction and an orthogonal transform and playing back data from the recording medium. In a data arrangement of a digital video signal, an I picture which can be independently represented in a picture is divided into n areas in the vertical direction, and the data is arranged from the front of one GOP in the unit of area by giving a priority to an area located at the center of the screen. A playback picture is outputted by playing back the I picture read from the recording medium in the unit of area unit. In the case where the whole I picture area cannot be read within a definite time, the area which cannot be read are interpolated by the use of the data of the preceding screen.

Digital video signal record and playback device and method for selectively reproducing desired video information from an optical disk

Digital video signal record and playback device and method for giving priority to a center of an I frame

Digital video signal record and playback device and method for giving

A frequency demodulator which comprises a digital FM demodulating circuit for demodulating an inputted FM signal and outputting a digital demodulated signal, a discriminator for discriminating whether or not the value of the digital demodulated signal from the digital FM demodulating circuit deviates from an upper limit value or a lower limit value set for a normal demodulating range, and a circuit operable on the basis of a result of the discrimination performed by the discriminator for replacing the value of the demodulated signal deviating from the upper limit value or the lower limit value with a compensation value set to a value approximating the upper limit value in the case where the inputted FM signal which has been demodulated is of a type having upper and lower side-bands suppressed and emphasized, respectively, or with a compensation value set to a value approximating the lower limit value in the case where the inputted FM signal which has been demodulated is of a type having upper and lower side-bands emphasized and suppressed, respectively.

Frequency demodulator with reversal phenomenon compensation

A frequency demodulator includes an analog-to-digital converter for converting an inputted FM signal into a digital signal. A 90.degree. phase shifter is used to phase shift the converted digital signal. The phase shifted signal and the converted signal are utilized to determine the results of tan.sup.-1 (X/Y). X represents the converted signal, and Y represents the phase shifted signal. The result from the calculation is delayed for a period of time equal to one sampling cycle. The frequency demodulator also includes a subtractor for subtracting the delayed signal from the calculation result. A discontinuity corrector corrects any discontinuity in an output from the subtractor, and a reversal phenomenon compensator compensates the output from the discontinuity corrector when the output from the discontinuity corrector exceeds a predetermined range of levels. These levels correspond to an appearance of discrete lines of black or white color on a reproduced picture.

Digital FM demodulator with distortion correction

Growing community of inventors

Nagaokakyo, Japan

Takahiro Nakai