MUSE-SYSTEM TELEVISION RECEIVER

摘要

PURPOSE:To prevent ghost image from occurring by controlling the entire mixing circuit to operate an animation-area-insertion processing by detecting the unlock of a PLL circuit by means of the phase difference between a horizontal synchronizing signal and a window signal generated by frequency-dividing a system clock. CONSTITUTION:The outputs from insertion filters 21 and 22 are inputted to an animation-adoptive stell-area-animation-area-insertion mixing circuit 27, whose proportion of mixing is controlled by the output from an animation detection circuit 26 using a ROM 24. When the PLL circuit goes out of phase because of disturbance, the phase of the window signal 17a generated by an HD window setting circuit 17 and that of the detection synchronizing signal from an HD detection circuit 12 become different from each other, and a signal 12a is not outputted. Therefore, the output of a retrigger monostable-multi vibrator 18 does not last but turns to 'L'. Then an unlock displayer 19 that includes a photo diode turns on, changing an unlock signal 201 to 'L'. And the ROM 24 is controlled to operate for that all the insertion filters of the mixing circuit 27 are changed to the animation area.