Abstract: A capacitor for outputting a reference signal is formed by using a part of an envelope. A reference signal according to an anode voltage is output from the capacitor for outputting a reference signal. An unnecessary signal component included in an index-detection signal which is output via the capacitor for outputting an index signal is eliminated on the basis of the reference signal. With the configuration, only the required index-information signal is extracted from the index detection signal with high accuracy at a high SN ratio.

Abstract: A display apparatus according to the present invention includes an electron beam landing pattern correction coil disposed at the rear side of a deflection yoke provided on a cathode-ray tube and a correction current generating device for generating a correction current corresponding to an electron beam landing pattern and supplying the current to this electron beam landing pattern correction coil. This correction current is obtained by selectively combining a plurality of waveform current components (e.g., DC current component, a saw-tooth wave component, a parabolic waveform component, a sine waveform component, etc.) which can respectively correct a plurality of fundamental electron beam landing patterns in response to a difference in beam-landing position. Thus, after the display apparatus has been manufactured, the difference in beam-landing position of the manufactured display apparatus can be corrected to the details on the whole screen.

Abstract: An image display correcting apparatus of the invention comprises, broadly, a correction data forming apparatus and an image display apparatus. Correction data for correcting a display state of an image is formed by the correction data forming apparatus on the basis of an image as a reference displayed on the screen of a CRT. Further, on the basis of the correction data, an operation of correcting image data is executed so that an image is accurately displayed on the image display apparatus. The corrected image data is outputted to the CRT. Thus, a defective display state such as image distortion, misconvergence, or the like can be corrected at low cost and a high quality image can be displayed.

Abstract: An image control device and method, and image display device, capable of producing an image of high quality by joining a plurality of divided frames with the joint areas made inconspicuous. An index electrode is provided in an over-scan region on the side of the joint area of the right and left divided frames. The index electrode outputs a detection signal in response to an electron beam scanning in the over-scan region. Based on the detection signal, obtained is data on a pixel position in the joint area of the divided frames. Further, based on the data on the pixel position thus obtained, estimated is data on a pixel position in an area other than the joint area of the divided frames. Meanwhile, using data obtained based on the detection signal outputted from the index electrode, control of image data is exerted so that the left and right divided frames are joined properly.

Abstract: A capacitor for outputting a reference signal is formed by using a part of an envelope. A reference signal according to an anode voltage is output from the capacitor for outputting a reference signal. An unnecessary signal component included in an index detection signal which is output via the capacitor for outputting an index signal is eliminated on the basis of the reference signal. With the configuration, only the index information signal required is extracted from the index detection signal with high accuracy at a high SN ratio.

Abstract: With the cathode ray tube and image correcting method of the invention, inside the cathode ray tube, an index electrode for outputting an electric detection signal according to an incidence of electron beams is provided in an over-scan region of the electron beams on the side of the joint of neighboring left and right divided screens. Based on a detection signal outputted from the index electrode, image display control is performed so that the left and right divided screens are joined in an appropriate positional relationship. Also, based on the detection signal outputted from the index electrode, brilliance modulation control at the joint area of the left and right divided screens is performed and thus image display control is performed so that changes in brilliance at the joint area remains inconspicuous.

Abstract: A cathode ray tube apparatus can accurately, easily and automatically correct influences exerted on both of a beam landing drift and an image distortion drift by terrestrial magnetism applied to a cathode ray tube (CRT). A correction current based on an output of a terrestrial magnetism sensor (45) is supplied to a Z-axis correction coil (41) and an X--X axis correction coil (42). A terrestrial magnetism component (B.sub.H cos.theta.) of Z-axis direction is canceled by a correction magnetic flux generated by the Z-axis correction coil (41), and a terrestrial magnetism component (B.sub.H sin.theta.) of X-axis direction is canceled by the X--X axis correction coil (42), whereby a beam landing drift and a image distortion drift are corrected automatically.

Abstract: A dynamic convergence device in a color cathode-ray tube has two pairs of confronting high- and low-voltage electrode plates disposed in a color cathode-ray tube bulb and arranged such that a central electron beam will pass between the high-voltage electrode plates and side electron beams will pass between the high-voltage electrode plates and the low-voltage electrode plates. A first parallel-connected circuit is composed of a first resistor and a first diode which are connected between the low-voltage electrode plates and a high DC voltage source. A second parallel-connected circuit is composed of a second resistor and a second diode which are connected between the high-voltage electrode plates and the high DC voltage source.

Abstract: A dynamic convergence apparatus of a simplified arrangement can reduce a distortion of a beam spot on a periphery of a picture screen and improve a focusing, wherein a parallel circuit of a high resistance value resistor (R) and a diode (D) is connected between low voltage side electrode plates (3), (4) and high voltage side electrode plates (1), (2) to which an anode voltage (HV) is applied, a capacitor (C) is formed by coating a conductive layer on the inside and outside of a tube envelope of a color CRT while glass of the tube envelope is used as a dielectric material, and a convergence voltage which results from adding a vertical parabolic wave voltage to the horizontal blanking period of a modulated voltage provided by amplitude-modulating a DC voltage very slightly lower than the anode voltage (HV) by horizontal and vertical parabolic waves is commonly supplied from one end side (outside of the tube envelope) of the capacitor (C) to the low voltage side electrode plates (3), (4).

Abstract: An electronic circuit automatically corrects the convergence of an electron beam of a color cathode ray tube. Light reflected upon scanning by the electron beam of an index pattern disposed at a predetermined position on the shadow mask of the color cathode ray tube is detected by a photodetector. A detected signal representative of the scanning position of the electron beam is obtained, and convergence error information is obtained based on the detected signal. The correcting circuit comprises an integrator for integrating the detected signal produced during a plurality of traverses of the index pattern by the electron beam. The convergence error information is based on the result of the integration. The effect of noise included in the detected signal is thereby reduced, and convergence correction with increased accuracy is obtained.

Abstract: A dynamic white uniformity correcting apparatus for a three-color display for displaying a color picture in response to three primary color signals and includes a cathode ray tube which has means for emitting a plurality of electron beams and a display screen divided into a plurality of incremental areas and the display also includes deflection means for scanning the plurality of electron beams across the display screen to produce the color picture in response to three primary color signals and wherein a correction signal generating means generates at least two correction signals for each incremental area of the display screen and the correction signal generating means includes a correction signal storage means for storing the correction signals.