Videosignalverarbeitungsgerät

• Main Author: IKUHARA, HIDEYUKI, SUITA-SHI OSAKA, JP
• Format: Patent
• Language: German
• Published: 17.08.1995
• Edition: 6
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

A video signal processing apparatus for processing a video signal including SYNC pulses, a time-compressed color difference and luminance signal, compression factors of these signals being different from each other, the color difference signal and the luminance signal being transmitted sequentially for one horizontal line for simultaneously outputting time-reproduced color difference and luminance signals comprises: first (12) and second (14) time-expansion circuits for producing the time-reproduced luminance and color difference signals in response to first and second clocks respectively; a switching circuit (32) for selectively outputting the time-reproduced color difference signal in response to a control signal; a PLL (330) responsive to the video signal including a frequency dividing circuit (316) for producing the first and second clocks, and a synthesized SYNC pulse; and a phase detecting circuit (313) for detecting a phase relation between the video signal and the synthesized SYNC pulse to produce the control signal. When the PLL (330) is out of phase with the SYNC pulse, i.e., not locked, the switch (32) does not transfer the color difference signal from the second time-expansion circuit (14), preventing time-reproduced signals from producing a double image on a display (18).