| 摘要 |
PURPOSE:To attain color reproduction with fidelity, by providing a correction circuit detecting the missing of index pulses and interleaving a prescribed number of index pulses, between a pulse forming device and a frequency converter. CONSTITUTION:In a color TV receiver using an index picture tube, a correction circuit 17 is provided between a pulse forming device 8 and a frequency converter 9. A monostable multivibrator 13 of the correction circuit 17 detects the missing of index pulses and the period of a detection signal of low level of the vibrator 13 produced due to this missing can be extended with a monostable multivibrator 14. This signal is inputted to an FF15 an NAND gate 16 obtains the NOT of outputs of the FF15 and of the device 8, and when the number of missings is 1-3, three index pulses are interleft and inputted to the frequency converter 9 to coincide the input with a time point of the output of a reference pulse upon no missing is realized. Thus, even if the missing is produced, the color synchronism can be executed for color reproduction with fidelity. |
