Sony Corporation

Kinya Shinkai

Yoshio Ishigaki

Susumu Yoshida

Katsuo Isono

Takao Tsuchiya

Senri Miyaoka

Susumu Akazawa

Kiyonori Tominaga

An aperture compensation circuit which includes a first differentiating circuit for differentiating an input signal to its input terminal to provide a primary differentiated signal, a squaring circuit for squaring the primary differentiated signal to provide a first signal, a second differentiating circuit for differentiating the primary differentiated signal from the first differentiating circuit to provide a secondary differentiated signal as a second signal, and a dividing circuit for dividing the first signal by the second to provide a contour compensation signal which is not affected by the steepness degree of the input signal.

Aperture compensation circuit

Beam index color cathode ray tube with color-identifying patterns of

A beam index type color television receiver having a beam index type color cathode ray tube which includes a screen having a plurality of groups of color phosphor elements and index phosphor elements, an index signal sensing device for detecting index signals from the index phosphor elements and generating index pulses, a frequency multiplier for providing a timing signal with a frequency that is a multiple of the frequency of the index pulses, a gate signal generator supplied with the timing signal from the frequency multiplier and generating a plurality of gate signals, a gate circuit for sequentially selecting, response to the gate signals three primary color signals desired from an input video signal and supplying the selected primary color signals to the cathode ray tube, and a velocity modulating device for modulating the beam scanning velocity of the cathode ray tube. To control the modulation of the beam scanning velocity, a video signal level detecting circuit detects the level of the input video signal, and a velocity modulating signal generating circuit supplies a velocity modulating signal to the velocity modulating circuit in response both to the output of the video signal level detecting circuit and to the timing of the index pulses.

Beam index type color television receiver

A method and apparatus for improving the sharpness of a video picture displayed on the screen of a cathode ray tube. At least one electron beam scans the screen in line-scanning and vertical directions, respectively, the electron beam having its intensity modulated in accordance with a video signal. The scanning velocity of the electron beam is modulated in the line-scanning direction in accordance with transitions of the video signal which correspond to transitions between high and low brightness levels of the displayed video picture. Each electron beam is shaped to have a substantially oval shape whose longer axis is disposed in the line-scanning direction and whose shorter axis is disposed in the vertical direction, whereby the oval-shaped beam impinges upon the display screen and the sharpness of the displayed video picture in the vertical direction is improved.

Method and apparatus for improving the sharpness of a video picture

In a beam index color television receiver having the screen of its color cathode ray tube provided with a repetitive pattern of a plurality of groups of different primary color phosphor elements arranged side-by-side across the image area of the screen to be scanned by a single electron beam as the latter is selectively modulated by respective color signals, index and mode set signals are provided in response to scanning by the beam of respective locations on the screen which are interspersed across the latter with distances therebetween which are non-integrally different from the pitch of the groups of color phosphor elements, and with adjacent locations corresponding to the mode set signal being spaced apart by an integral multiple of such pitch. The index signal can be provided by the scanning with the beam of index elements at the corresponding locations on the screen which emit light or other radiant energy, while the mode set signal may be provided in response to the absence of the index elements at the respective locations or to the presence, at the latter locations, of mode set elements which emit distinctive radiations when scanned by the beam. In any case, a gate pulse generator is responsive to the index signal to provide sequentially repeated gating signals by which the color signals are gated to selectively modulate the electron beam, and the phase and sequence of the gating signals are controlled in response to the mode set signal for ensuring that, as the beam scans each color phosphor element, the beam is modulated by the corresponding color signal.

Beam index color cathode ray tube

In a video signal reproducing apparatus having a cathode ray tube in which at least one electron beam is made to scan a screen in line-scanning and vertical directions while the intensity of the beam is modulated to establish the brightness of a video picture to be displayed on the screen, and in which bright picture portions are represented by respective high level portions of a video signal defined between rising and falling edges extending from low level signal portions representing contiguous dark picture portions; a waveshaping circuit receives the video signal and acts thereon to provide a compensated video signal in which the width of each high level portion between the respective rising and falling edges is increased, the compensated video signal is employed to control the intensity of the electron beam, the rising and falling edges of each high level portion of the video signal are detected to provide a beam velocity modulation signal with respective positive and negative peaks by which the scanning velocity of the beam in the line-scanning direction is modulated, and the positions of such positive and negative peaks are shafted, relative to the corresponding peaks of a differentiation of the video signal, in the directions toward the adjacent low level signal portions of the compensated video signal.

Video signal reproducing apparatus with electron beam scanning velocity

An aperture correction circuit is disclosed in which the first portions of the differentiated signals of input video signals are inverted, and the waveform shaped signals thus obtained and the input video signals are added together whereby the corrected video signals having sharp edged waveforms are obtained.

Growing community of inventors

Yokohama, Japan

Kinya Shinkai