| 摘要 |
<p>PURPOSE: To simplify the circuit configuration by connecting two stages of frequency 2-multiple circuits each provided with a multiplier means that outputs a 2-multiple signal and generating a clock signal to generate a blue image. CONSTITUTION: The circuit is made up of a frequency 2-multiple circuit 10 that receivers a color subcarrier signal fsc and multiplies the signal by a multiple of two and a frequency 2-multiple circuit 20 at receives the signal multiplied by a multiple of two and provides an output of a signal 4 fsc being a multiple of 4. Then an original period wave and a delay wave are rectangle-converted by a means such as a saturation amplifier and the result is given to a 2-input EXOR circuit or an EXNOR circuit, then a waveform having two pulses for each period is obtained. That is, this is equivalent to 2-multiple. However, in order to maximize the multiple efficiency in terms of the energy, it is desirable that each pulse width has 0.25 period in the waveform having the two pulses and the interval of the pulses is 0.25 period. Thus, a 90 deg. phase shift means is included to maximize the conversion efficiency.</p> |
