Victor Company of Japan, Limited

Hitachi, Ltd.

Matsushita Electric Industrial Co., Ltd.

Yuichi Ikemura

Toyotaka Machida

Yasuaki Watanabe

Teruaki Noda

Makoto Furihata

Daisuke Murakami

Yukio Okabe

Mitsuru Hayakawa

Hitoshi Aoike

Toshimasa Kumazaki

Yasuhiro Fujita

Hiroshi Takano

An automatic white balance adjusting circuit comprises a color temperature detecting circuit for producing a detection signal having a voltage in correspondence with a color temperature of an incoming light to an image pickup device, a reference voltage signal generating circuit for generating an A.C. reference voltage signal, a comparing circuit for obtaining a discrimination signal by comparing the detection signal with the reference voltage signal, a plurality of voltage sources for applying different voltages in correspondence with different color temperatures, a selecting circuit for selecting and obtaining voltages from the voltage sources depending on the output discrimination signal of the comparing circuit, and an integrating circuit for integrating output voltage signals of the selecting circuit. Output voltage signals of the integrating circuit are applied to corresponding amplifiers to variably control amplifications thereof so that a white balance of a color video signal produced from an encoder is automatically adjusted.

Automatic white balance adjusting circuit for image pickup device

An automatic white adjusting circuit for a television camera in which a rough adjustment is first performed with an adjustment quantity of large steps, and fine adjustment is secondly performed with an adjustment quantity of small steps, upon automatic adjustment of the white by performing such operations as directing the television camera towards a white surface. According to the automatic white adjusting circuit of the present invention, the adjusting accuracy of the white balance can be improved, and the white adjustment can be performed automatically within a short period of time.

Automatic white adjusting circuit for a television camera

A rotary recording medium reproducing apparatus reproduces a recorded signal from a rotary recording medium by use of a reproducing element. The rotary recording medium is recorded with at least a first carrier signal which is modulated by an information signal having a synchronizing signal of a predetermined frequency. The reproducing apparatus comprises a motor for rotating the rotary recording medium, a reference signal generating circuit for generating a reference signal having a frequency equal to a horizontal scanning frequency of a video signal of a standard television system which is characteristic of the reproducing apparatus and should originally be reproduced, or equal to 1/M (M is an integer) times the above horizontal scanning frequency, a detecting circuit for detecting a signal respective of the rotational speed of the rotary recording medium, and a comparator for comparing the reference signal and the signal respective of the rotational speed of the rotary recording medium, to control the rotational speed of the rotary recording medium by a compared output signal thus obtained, so that the synchronizing signal within the reproduced signal is reproduced at a frequency equal to the horizontal scanning frequency of the above standard television system with which the reproduction should originally be performed.

Means for compatibly reproducing video discs recorded according to

An automatic white adjusting circuit for a television camera having a color image pick-up tube comprises a first and second variable gain amplifiers for amplifying two predetermined primary color signals of the three primary color signals from an output signal of the image pick-up tube, a matrixing circuit for producing a luminance signal and two color difference signals, by being supplied with either said luminance signal from the output of the image pick-up tube or one remaining primary color signal of the three primary color signals, and outputs of the first and second variable gain amplifiers, an averaging circuit for producing a first and second white detection signals by substantially averaging all or a part of the respective video duration time of the output color difference signals from the matrixing circuit, reference level producing circuit in which a reference level equal to a DC current level of the two predetermined color difference signals of the output signal of the image pick-up tube upon image-picking up of a white object by the image pick-up tube is produce, first and second level comparators for respectively comparing the levels of the first and second white detection signals from the averaging circuit with the reference level from the reference level producing circuit,, and first and second control voltage producing circuit for producing a first and second control voltages according to the outputs of the first and second level comparators. The first and second control voltages are supplied respectively to the first and second variable gain amplifiers, and controlling their respective gains so that the two color difference signals from the matrixing circuit upon image-picking up of the white object by the image pick-up tube become to substantially zero.

A synchronizing signal generator device for television includes an oscillator circuit which generates a color subcarrier signal, a voltage-controlled oscillator circuit which includes a counter and whose oscillation frequency is controlled by the output signal of the first-mentioned oscillator circuit, a counter which receives an output of the voltage-controlled oscillator circuit, and a decoder which receives an output of the second-mentioned counter. The decoder provides a synchronizing signal for the NTSC, or SECAM format in such a manner that the count numbers of the respective counters are controlled. The synchronizing signal generator device for television also includes various circuits for receiving external synchronizing signals. As a result, the synchronizing signal generator device for television can be synchronized with another synchronizing signal generator device for television.

Synchronizing signal generator device for television

A signal generating circuit in a color television system comprises a circuit for producing a signal of a frequency of 282 nfh (where n is an integer, and fh is a PAL-system horizontal scanning frequency) or a signal of a frequency closely approximating 282 nfh, a frequency-divider for frequency-dividing to 1/161 the signal of the frequency 282 nfh or a frequency closely approximating 282 nfh, and a circuit for forming, while satisfying the relationship (282.times.162) nfh.apprxeq.161 nfsc (where fsc is the PAL-system chrominance sub-carrier wave frequency), a signal of a frequency closely approximating the frequency fsc or of the frequency fsc and signals of frequencies fh and fv (where fv is the PAL-system vertical scanning frequency) or of frequencies respectively closely approximating the frequencies fh and fv.

Signal generating circuit in a color television system

A variable frequency oscillator comprises an oscillating loop and a variable phase shifter for imparting one of two different phase shifts depending upon the polarities of a DC control voltage to a signal from the oscillating loop. The phase-shifted signal has its amplitude controlled by the amplitude of the control voltage and is combined with the signal in the oscillating loop. The vector sum of the combined signals determines the phase angle of the oscillator signal and hence the frequency thereof.

Growing community of inventors

Nagareyama, Japan

Yuichi Ikemura