Sony Corporation

Mitsubishi Rayon Company, Limited

Fumio Ishikawa

Kuninobu Tanaka

Shinichi Kitazono

Shinichi Tsutsumi

Naoyasu Gamou

Akira Sato

Nobuyuki Ishikawa

Tetsuo Yamamoto

Hiroshi Higuchi

Shinichi Tanabe

Hisaaki Narahara

Yukio Tsuda

Hiroshi Numata

Shinchi Kitazono

Kazuhiro Zenba

Keiji Yagi

Yukihiro Sekiguchi

Takayuki Aoki

Tamotsu Kogo

A system to easily detect defective portions of a transmission line in a short time, wherein the optical signal which has been generated on the basis of the transmission pulse which is outputted in synchronization with the horizontal synchronized signal is transmitted via the transmission line, and the reflected-light component which has been reflected by the defective portion in the transmission line is received, and the gain of the reflected-light component is increased by one step for each predetermined number of a horizontal lines on the basis of the horizontal synchronized signal and then compared with the reference voltage, so that the binary data is obtained. The binary data is displayed, along with the axis of the abscissa which represents the distance of the transmission line corresponding to the time difference between the optical signal and the reflected-light component, and the axis of the ordinate which represents the signal level of the reflected-light component.

Defective portion detecting device with a horizontal synchronized signal

An integrated oscillation circuit used for frequency conversion circuit in which UHF frequency conversion and VHF frequency conversion are selectively energized to use a common IF amplifier. The integrated oscillation circuit is used for a local oscillation circuit. The integrated oscillation circuit including a connection terminal connected to an external resonance circuit and an input line of a mode switching signal which is set at a different level in response to an operation mode, an oscillation element, a bias terminal of which is connected to the connection terminal, a detection circuit detecting the level of the mode switching signal applied to the bias terminal of the oscillation element, and a switching circuit turning on and off a power source for driving the oscillation element in response to the level detected at the detection circuit.

Integrated oscillation circuit used for frequency conversion circuit

Frequency conversion circuit with UHF/VHF common PLL buffer

Light-emitting diode drive circuit with fast rise time and fall time

A Digital Phase Comparator has a simplified logic circuit in which Nand Circuits provide UP and DOWN signals containing phase information about E and F signals.

Digital phase comparator for use in a phase lock loop

An RF modulator comprising an FM modulator supplied with an audio signal, and AM modulator supplied with the FM modulator output and a video signal, an oscillator for generating a sound subcarrier signal, and an oscillator for generating a main carrier signal. Each of the oscillators consists of a VCO with a PLL circuit, and the entire components are composed of a single IC chip so as to be formed into a compact miniature structure. A modified RF modulator includes a PLL circuit for varying the oscillation frequency of a VCO by a variable frequency divider, and a modulation circuit supplied with a modulating signal and the oscillation output of the VCO. The division ratio (integer) of the variable frequency divider is continuously varied, and the reference frequency of a reference oscillator is set to be less than a predetermined channel interval frequency, thereby reducing the frequency error in the modulated signal output.

Audio-video modulator system on IC chip

A two phase voltage signal generating circuit for generating a pair of trapezoidal wave signals of phases opposite to each other is disclosed which includes an input terminal supplied with an input pulse signal, a capacitor, a pair of voltage limiting circuits connected to both ends of the capacitor respectively and for limiting the voltage at each end of the capacitor within a predetermined voltage range, a current control circuit controlled by the input pulse signal and for supplying a charge or discharge current to the capacitor to generate the pair of trapezoidal wave voltage signals at the both ends of the capacitor, a detecting circuit for detecting the change of the intermediate voltage of the trapezoidal wave voltage signals and a symmetry control circuit controlled by an output of the detecting circuit and for controlling the charge or discharge current such that the pair of trapezoidal wave voltage signals become substantially symmetrical to each other.

Two phase trapezoidal signal generating circuit

A buffer circuit includes a main buffer circuit section formed of a pair of complementary input side transistors the bases of which are connected together to an input, a dummy circuit section having the same circuit construction as the main buffer circuit section, and a feedback signal section compares the output from the dummy circuit section with a predetermined value to provide a feedback signal which is supplied to the dummy circuit section and the main buffer circuit section so as to make the output of the dummy circuit section equal to that predetermined value.

High speed buffer circuit particularly suited for use in sample and hold

A sample and hold circuit is disclosed, in which first and second terminals to which are supplied drive currents for turning ON and OFF a diode bridge are respectively connected through capacitors to a connection point between output electrodes of switching elements, a diode is connected between the first and second terminals for short-circuiting the capacitors when the diode bridge is made OFF, and input electrodes of the switching elements are respectively connected to first and second points of a reference potential whereby said diode bridge is made ON by a drive current flowing from the first point to the second point of the reference potential.

Sample and hold circuit

A high frequency wide band resonant circuit is formed of a lump capacitor, a lump inductor and a voltage controlled variable capacitor. The resonant circuit is suitable to be used in a receiving circuit which selectively receives a signal in the UHF band.

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Kanagawa, Japan

Fumio Ishikawa