| 摘要 |
PURPOSE:To attain vertical resolution correction in double speed conversion without narrowing the band of a luminance signal by using a band limit circuit so as to limit the band of one of two luminance signals having different bands so as to add both the signals. CONSTITUTION:A double speed luminance signal Y5 given to a transistor (TR) 18 is subject to band limit up to the same band of a double speed luminance signal, inverse of Y6 inputted to a TR 19 by a band limit circuit 31 (filter) comprising resistors 32, 33 and a capacitor 34. Then the signal is added to the signal, inverse of Y6, and only the rewriten signal of double speed is extracted by a blanking circuit 16 and the result goes to a correction signal D2. Since no high frequency is supplied to the correction signal D2 generated in such a way, even when a difference is operated between the double speed luminance signal Y5 and the correction signal D2 by using a differential amplifier comprising TRs 20, 21, a resistor 28 and a constant current source 30, the luminance signal is corrected without decreasing the characteristic of high frequencies.
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