Matsushita Electric Industrial Co., Ltd.

Teruo Kitani

Takayuki Sagishima

Takaaki Baba

Reiichi Sasaki

Tatsuo Fujita

Yasuo Nakajima

Eiichi Tsuboka

Masanobu Tanaka

Takashi Nagata

Hirokazu Yoshino

Toshiro Ishikawa

Masao Nakazawa

An apparatus is provided for synchronizing left-and right-eye images and for providing a composite video signal for a stereoscopic television system. The synchronization operation at a field-by-field rate is assured by detecting the phase-difference between a first vertical sync pulse which is derived from the vertical sync signal which is sampled by a horizontal sync signal and a second vertical sync pulse which is constantly delayed from the vertical sync signal of the composite video signal. As a result, the left eye image is always associated with the left eye lens of the viewer and the right eye image is always associated with the right eye lens of the viewer.

Field recognition circuit

A color signal demodulating device designed so that a local subcarrier oscillator generates a demodulating signal which is both synchronized and inverted in phase with respect to a color signal at each horizontal scanning period so as to demodulate an R-Y signal and which reverses phase with each horizontal scanning period; a bust signal and a signal inverted in phase therefrom are alternately switched therebetween and used to drive the local subcarrier oscillator. The output of this local subcarrier oscillator can be used for both the demodulation signal for the R-Y carrier and as the demodulation signal for the B-Y demodulator.

Color demodulating apparatus

In the PAL system, the demodulating axis for one of the two color difference signals, i.e. the R-Y signal, is transmitted switched in phase 180.degree. at each horizontal scanning period. In order to reproduce this signal, a demodulator circuit for color television signals is provided for producing a R-Y signal of the correct polarity, using a line switching signal not controlled by the phase of the transmission signal, and having a frequency half that of the horizontal frequency.

PAL Demodulator having non-synchronized line switch

A television receiver including: television signal receiving means for simultaneously receiving two different television signals to produce two different image signals, a first and a second image signal corresponding to the television signals; synchronous signal producing means for producing vertical synchronous signals and horizontal synchronous signals from the two image signals; memory means for sampling and storing the second image signal; driving pulse producing means for producing driving pulses to drive the memory means in accordance with the synchronous signals supplied to the driving pulse producing means from the synchronous signal producing means; mixing means for producing a mixed image signal by inserting, into the first image signal under the control of the driving pulses, the second image signal read out from the memory means by the driving pulses; and display means for displaying the output of the mixing means; wherein the second image signal of each horizontal synchronous period is sampled by the memory means into N.sub.H sampled signals, and n sampled signals which are sampled from n adjacent horizontal lines of the second image signal, respectively, and which correspond to each other in vertical direction on a TV screen are summed and integrated into one sampled image signal element whereby N.sub.H sampled image signal elements for one horizontal synchronous period upon read-out are formed from n.times.N.sub.H sampled signals of n adjacent horizontal lines and stored by the memory means. Since the information of all of the n adjacent horizontal lines is utilized for the displayed image, the displayed image can be of high quality.

Television receiver

A color television receiver receiving two television signals of different channels, compressing the time axis of one of the television signals, and inserting this compressed television signal in a portion of the other television signal for displaying the pictures of the two channels on the same screen. In the receiver, the luminance signal, chrominance signal and synchronizing signal are derived from each of the received two television signals. A writing clock pulse signal is produced on the basis of one of the synchronizing signals for writing the luminance signal and chrominance signal in the corresponding television signal in a memory circuit, while a reading clock pulse signal is produced on the basis of the other synchronizing signal to read out the luminance signal and chrominance signal from the memory circuit in a relation in which these signals are compressed in the time axis. After the luminance signal and chrominance signal read out from the memory circuit are adjusted in their signal levels relative to the luminance signal and chrominance signal in the other television signal, a portion of the luminance signal and chrominance signal in the other television signal is replaced by the luminance signal and chrominance signal read out from the memory circuit so that the pictures of the two channels can be displayed on the same screen.

Color television receiver for simultaneous display of plural programs

An image display apparatus has an: image signal receiver for simultaneously receiving two different image signals, a first image signal and a second image signal; a memory for writing therein the second image signal; controlling means for controlling the writing position, writing frequency, writing sequence, reading-out sequence, reading-out frequency and start-timing of reading-out of the second image signal; a display for displaying full picture information or partial picture information of the second image signal a part of a displayed picture of the first image signal by selectively reading-out the second image signal under the control of the controller; and zoom-up device for stepwisely or continuously varying the writing position and reading-out position of the second image signal controlled by the controller so as to zoomwisely display the full or partial picture of the second image signal on the picture of the first image signal.

Composite image display apparatus

A frequency discriminating apparatus is constituted by a piezoelectric ceramic resonator, a reference capacitor, a pre-amplifier including a broad tuning circuit, a pair of amplitude detectors, and a differential amplitude limiter. The piezoelectric ceramic resonator is made of a piezoelectric lead titanate ceramic plate having a pair of electrodes covering the entire area of the major surfaces thereof, and the plate is poled with a poling field of not less than 50 kV/cm in the thickness direction. The thickness of the plate is chosen so as to cause the plate to vibrate in the thickness-extensional vibration of the 3rd harmonic overtone at a preselected frequency when an electrical signal is applied to the pair of electrodes. The differential amplitude limiter differentially adds the two signals detected by the two amplitude detectors and limits the peak output voltage amplitudes to a predetermined amplitude. The center frequency for the frequency discrimination by this apparatus can be stably maintained according to this apparatus, and the apparatus can be easily manufactured in the form of integrated circuits without necessitating many value adjustments of circuit elements.

Frequency discriminating apparatus

A VTR signal discriminating apparatus for a television receiver generates discriminating signals when the receiver having this apparatus is receiving signals e.g. from a home use video tape recorder (VTR). This apparatus detects video head switching noises mixed in signals from the VTR having two video heads which are alternately switched every field of the signals by counting the number of apparent sync signals received within a given period of time. Thus, video signals originating from a broadcast station are distinguished from video signals originating from the VTR and the invention output denotes the presence of the appropriate signal. A television receiver can be modified in response to the invention output to accommodate the characteristics of the particular video signal received.

Growing community of inventors

Takatsuki, Japan

Teruo Kitani