PURPOSE: To reduce remaining jitters and color dislocation by generating a writing clock by a horizontal synchronizing signal and a burst signal overlapped at every time-base-compression multiplex signal. CONSTITUTION: A burst signal of single frequency is overlapped at a front porth in a horizontal blanking period of plural video signals. Image signals applied with time-base-compression supplied to an input terminal 21 of a time-base corrector 15' at the time of reproduction are taken out at their horizontal synchronizing signals by a horizontal signal separation circuit 22, and a frequency fM of a master clock is generated in a PLL27. On the other hand, only burst information of said video signals is taken out by a burst gate BG37. An 1/i divider 36 is a circuit to divide the frequency fM of the master clock into 1/4 so as to write and generate the frequency f c of a writing clock; and by resetting signals by burst information, the rise of a burst signal and that of a writing clock of the output of the divider 36 are set closest in phase. Moreover, a phase comparator PC38 detects their fine dislocation in phase and coincides a writing clock with that of a burst from a phase shift circuit 39 in phase. COPYRIGHT: (C)1985,JPO&Japio

Recording/reproducing device

PURPOSE: To decrease the jitter of a reloading signal at the time of reproduction by compressing with a time base and arranging two color difference signal and luminance signal in one horizontal period and inserting a synchronizing signal for expanding between a horizontal synchronizing signal and time based- compressed signal CONSTITUTION: Input signals C1', C2' and Y' are respectively converted to the digital data by A/D converters 11∼13 and simultaneously written to memory circuits 21∼23 On the other hand, from the horizontal synchronizing pulse of a synchronizing separating device 8, a clock pulse for reading of the 5/7 period of a writing clock pulse is generated by a clock generating device 62, and from an address generating device 72, a reading address is generated, and the data are read from the memories 21∼23 At such a time, a pattern memory 3 is prepared in which a horizontal synchronizing signal HS, a pedestal level PD, an achromatic color level DB and a burst signal BS, a syncronizing signal for expanding are pattern data, and read while a multiplexer 4 is changed over in the order of a memory 3 and memories 21∼23, and through a D/A converter 5, the time base compressed multiplexed signal TC shown in the figure is obtained COPYRIGHT: (C)1986,JPO&Japio

Video signal processing system

PURPOSE:To improve S/N of a video signal and to detect securely an identifying signal by overlapping a single wave signal having frequency lower than that of a carrier signal subjected to frequency modulation with an identifying signal part of a time division multiplex time base compression signal subjected to frequency modulation. CONSTITUTION:A time division multiplex time base compression signal D, that is, output signal of a time base compression circuit 2, is frequency-modulated by a frequency modulation circuit 3 and supplied to one input terminal of an adder circuit 4. A fixed contact point 5s of a changeover switch 5 is grounded, and simultaneously a single wave signal fI having a frequency sufficiently lower than that of a carrier signal subjected to frequency modulation is supplied to other fixed contact point 5i. Moreover, a movable contact point 5a connected to the other input terminal of the adder circuit 4 is synchronized with a luminance signal identifying signal IDY and a color difference signal discrimination signal IDC, both of which are obtained in the time base compression circuit 2, and connected to the fixed contact point 5i only when there are the IDY and IDC. At the time of reproduction, an identifying signal gate signal for going to a high level ''1'' only when the single wave signal fI exists is supplied as a gate signal to an identifying signal separator circuit 13 through a comparator circuit 15 and low pass filter 14 used for fetching the signal fI.

System for transmitting video signal

Transceiver system of color video signal

PURPOSE:Color signals are time compressed and are transmitted after being inserted in horizontal flyback periods.

Mita Seiichi

Papers

Color tv signal process system