Abstract: A color synchronizing circuit (120) of a color television receiver includes a PLL circuit having a phase detector circuit (12b), an LPF (12c), a VCO (12d) and a 1/4 frequency divider (12f). Color bursts extracted from a composite chrominance signal by a burst gate circuit (12a) are directly applied to an input of the above described PLL circuit through an adder (12g) in a burst period while being circulated through a loop including a delay circuit (12h) by a switch (12i). The delay circuit has a delay time which is equal to a period of the back porch of a horizontal synchronizing signal having the color burst inserted thereinto and is equal to integer multiples of a cycle of a chrominance subcarrier. Thus, the repetition frequency of the color burst sequentially supplied to the PLL circuit while being circulated through the above described loop becomes 16 times a horizontal frequency f.sub.H. As a result, the sidebands which appear at the intervals of f.sub.

Abstract: A television signal converter includes a CATV tuner having a channel converting function, a gain changing circuit for descrambling the output from the CATV tuner and the like, in order to convert a television signal such as a CATV signal formed by a scrambled video signal into a descrambled television signal of channel 3, for example. The descrambled channel 3 CATV signal outputted from the gain changing circuit includes noise in the reproduced audio signal since the audio carrier is influenced by gain changing. In the present invention, therefore, the audio signal is reproduced from an audio carrier extracted from the front stage of a gain changing circuit. Thus, the reproduced audio signal is released from noise caused by gain changing.

Abstract: A delay circuit for delaying an FM video signal is disclosed. The delay circuit includes an input for supplying the FM video signal, an output for producing a delayed FM video signal, and a delay line connected between the input and output for delaying FM video signal. The delay line is defined by a plurality of I.sup.2 Ls connected in cascade. The delay circuit further includes a phase comparator provided for comparing a phase between FM video signal at the input and the delayed FM video signal at the output and for producing a difference signal representing the phase difference. The difference signal is used for changing and injection current to be applied to the I.sup.2 Ls such that the delay effected in the delay line is made substantially equal to the required delay.

Abstract: A scrambling system of television signal includes a circuit for eliminating vertical sync pulses in a vertical sync pulse period and equivalent pulses in first and second equivalent pulse periods at opposite ends of said vertical sync pulse period. In place of the eliminated pulses, substitute pulses having a frequency equal to an integer times the frequency of horizontal sync pulses are deposited. A framing code inserting circuit is provided for inserting at least one framing code in the substituted pulses. The framing code is carrying information how the television signal is scrambled.

Abstract: An amplitude modulation circuit wherein a resonant circuit for the determination of the carrier-wave frequency is connected to the collector of one transistor forming a differential pair of transistors forming a differential amplifier having its ground terminal connected to a constant current source while an output terminal of the resonant circuit is coupled to the base of the other transistor forming the differential pair so as to apply a positive feedback to the other transistor thereby forming a carrier wave oscillating circuit, and a constant current adjusting means for dividing by switching the current to be supplied to one of the transistors of the differential pair is connected between the differential amplifier and the constant current source, such that, by supplying a modulating signal to the constant current adjusting means to vary the oscillating level of the carrier wave, a modulated signal at a constant modulation degree can be obtained from the base of the other of the transistors forming the di

Abstract: In a television image receiver provided with a vertical synchronizing circuit of a count-down system, a down counter to be reset in the an even number of pulse section among the pulses to be partitioned off by the undercuts in the vertical synchronizing signal during the synchronizing operation through the count inputs of the horizontal synchronizing pulses, and a decoder for selectively guiding the output of a plurality of flip-flop circuits constituting the down counter to generate given line selection pulses are provided in said vertical synchronizing circuit to provide a line selector at lower cost and free from error actions even at the weak electric field, etc.

Abstract: A color gain control circuit for use in a color television receiver set comprises manual and automatic gain controls which are connected in cascade fashion between a power source and a reference potential. The automatic gain control is positioned upstream of the manual gain control. By connecting the manual and automatic gain controls in cascade fashion as described above, these controls can be integrated together and the color gain control circuit can be simplified in its circuit construction, enabling the color amplification system to be integrated.

Abstract: A horizontal synchronizing circuit for use in a television receiver set comprises a horizontal AFC circuit so designed that an output from a voltage controlled oscillator oscillating at a frequency higher than a horizontal frequency is frequency-divided to provide a frequency-divided output which is then compared in phase with a horizontal synchronizing signal, the oscillating frequency of the oscillator being controlled by a signal indicative of the result of such comparison, and a horizontal APC circuit for driving a horizontal deflection circuit in response to the phase controlled, frequency-divided output. Various pulses for control and gating functions are synthesized by combining outputs of different frequencies from a frequency divider.

Abstract: A synchro separation circuit for use in a television receiver set comprises an amplitude separation circuit and a frequency separation circuit and is so simple in construction as to render it to be suited for the fabrication into an integrated circuit. In order to increase the separation sensitivity relative to the vertical synchronizing signal, the amplitude separation circuit is so designed that a discharge circuit adapted to conduct during at least the vertical synchronizing signal period of the composite video signal is connected in parallel to a discharge resistor for a capacitor connected between the input transistor of the amplitude separation circuit and an emitter-follower circuit for supplying the composite video signal to the input transistor after the impedance conversion has been effected.

Abstract: A saturation and contrast adjusting circuit for a color television receiver set comprises a chroma processing circuit branched off from a contrast adjusting circuit connected to a video detector circuit of the color television receiver set. A control signal of the contrast adjusting circuit is released during the burst period to enable the contrast and saturation adjustment to be carried out by such control signal. The saturation and contrast can be adjusted by a single gain adjusting circuit and the respective control characteristic curves of the contrast adjusting circuit and the chroma processing circuit can be brought into coincidence with each other.

Abstract: A picture stabilizing circuit in a color television receiver decodes a count value in a counter comprising a vertical synchronizing circuit of a pulse count system for generating an ineffective-rendering pulse covering a period including a vertical synchronizing period and an equalizing pulse period. The circuit is responsive to the ineffective-rendering pulse to render ineffective or mask for the pulse period a composite synchronizing signal being applied to a picture associated circuit, such as a horizontal automatic frequency circuit, a horizontal automatic phase control circuit, a synchronization detecting circuit or the like while a burst gate-pulse-generating circuit and a direct current restoring circuit are rendered ineffective during the period of the ineffective-rendering pulse. The circuit comprises a flip-flop for generating an ineffective-rendering pulse which is set responsive to one decoder coupled to the counter and is reset responsive to the other decoder coupled to the counter.

Abstract: A video tone control circuit is implemented in an integrated circuit and comprises a sharpness control for differentiating a rise and fall of a video signal for controlling the amplitude of a high frequency component in the thus obtained video signal with a variable gain amplifying circuit for providing a video signal with the differentiated output superimposed thereon, and a softness control for changing an attenuation amount of a high frequency component in the video signal with a low pass filter. Either of the variable gain amplifying circuit and the low pass filter is enabled responsive to the level between a first range or a second range of the direct current bias voltage, while the other is disabled.

Abstract: A color synchronizing circuit comprises a phase locked loop which includes a voltage controlled oscillator including a ceramic vibrator. Phase comparison is made of an intermittent color burst and the output of the voltage controlled oscillator and the phase comparison output is applied to a low pass filter. The low pass filter provides a control voltage associated with the phase difference of these two signals to the voltage controlled oscillator. The frequency variable range .DELTA.f of the voltage controlled oscillator is selected such that a relation .DELTA.f<.+-.f.sub.H is met with respect to the repetition frequency f.sub.H of the color burst. The low pass filter comprises a dual time constant circuit, which sufficiently attenuates a beat signal from the phase comparator, thereby to make narrow the pull-in range of the phase locked loop.

Abstract: A horizontal scanning circuit constituting a self-oscillation circuit, by providing a winding for feedback in a flyback transformer, and by positively feeding back the output signal from said winding to the base of horizontal power transistor. Since this constitution does not require transformer for impedance conversion, the circuitry is simplified.

Abstract: A video signal obtained through detection by a video intermediate frequency circuit is applied to a luminance signal circuit and a chrominance signal circuit. The luminance signal circuit comprises a luminance signal amplifier which does not include a delay line. A delay characteristic of a tuner and/or the video intermediate frequency circuit is selected a delay characteristic on the part of a transmitter, to offset a delay time difference between the luminance signal circuit and the chrominance signal circuit, whereby a delay line can be omitted in the luminance signal circuit, as described previously. Preferably, a surface acoustic wave device is provided in the tuner and/or the video intermediate frequency circuit, so that a group delay characteristic of the surface acoustic wave device and the delay characteristic on the part of the transmitter can offset the delay time difference between the luminance signal and the chrominance signal without employing a delay line in the luminance signal circuit.

Abstract: The present invention relates to an improved circuit arrangement for use in color television receivers for generating color level automatic control signal through utilization of VIR (Vertical interval reference) signal included in the vertical retrace interval of the television signal being transmitted, in which circuit arrangement, video signal and B-Y demodulation signal are each subjected to D.C. restoration, and further compared by a comparator to utilize the difference therebetween as the color level automatic control signal.

Abstract: A chrominance signal processing circuit in a color television receiver which comprises a bandpass amplifier, a burst gate pulse source, a subcarrier generator, a 90.degree. phase shifter for phase shifting the generated subcarrier, a B - Y demodulator and an R - Y demodulator both coupled to the bandpass amplifier and separately coupled to the subcarrier generator and the 90.degree.

Abstract: A switching regulated constant voltage power supply apparatus, wherein a direct current voltage obtained through rectification and smoothing of a commercial alternate current power supply input is applied to a direct current/alternate current converting circuit implemented by a blocking oscillator such that the oscillator makes self oscillation upon turning on of the commercial alternate current power supply to provide an output from the converting circuit, the oscillator is adapted to operate in synchronism with the output from a driver circuit which is energized with the output from the converting circuit, and an error detecter is provided to detect an error fluctuation after rectification and smoothing of the output voltage from the converting circuit such that the detected output controls the converting circuit, thereby to provide a direct current constant voltage.

Abstract: An input transformer arrangement includes an unbalanced signal suppress transformer for suppressing unbalanced signal carried in a feeder line extending between a television receiver and an antenna therefor, and an impedance transformer for dropping the impedance. These two transformers are arranged on one core for unifying and simplifying the arrangement.

Abstract: A tint control signal generator for a color television receiver for generating a tint control signal to be applied to a tint control for adjustment of the tint of the reproduced television image by the utilization of a reference signal included in the transmitted television information only during the time of predetermined vertical intervals, which reference signal is generally known as a VIR signal. The tint control signal generator comprises a zero clamping circuit for sampling a direct current component out of an appropriate output of the color demodulator during the vertical synchronizing interval, a zero level comparator for comparing a reference voltage level with the level of the appropriate color demodulator output during the chroma reference interval of the VIR signal and for generating the tint control signal if any difference exists as a result of the comparison.