Abstract: A cathode ray tube display apparatus having a protection circuit which cuts off supply of a synchronization signal, i.e., the horizontal and/or vertical synchronization signals, to a cathode ray tube driving circuit in response to a state signal indicating when frequencies of the synchronization signals exceed a limited range. The protection circuit prevents the cathode ray tube driving circuit from being damaged by abnormal variations in the frequencies of the synchronization signals.

Abstract: A remote control device is provided that is able to be programmed after initial manufacture to accommodate the control of additional apparatuses. The remote control device includes a multi-functional, interchangeable user interface where the interface is modified such that it is able to control the functions of a variety of different types of apparatuses.

Abstract: A spot is prevented from occurring on the center portion of a cathode ray tube when electric power is turned off by using a voltage charged in a capacitor which are used for outputting a vertical blanking signal in a vertical blanking signal generating circuit of an image display device for displaying an image in use of the cathode ray tube. The present invention is provided with a discharge cut-off element between a negative electric power source and the capacitor for outputting a vertical blanking signal and a discharging element for discharging a charged voltage of the capacitor to the ground. The present invention prevents a charged voltage ofthe capacitor from being discharged until thermoelectrons are not emitted from the cathode so as to supply a negative charged voltage to the first grid of the cathode ray tube continuously, so that a spot is prevented from occurring.

Abstract: A monitor protection system comprise a display power management signaling (DPMS) operating unit for performing a predetermined power control; a horizontal deflection detecting circuit for detecting a horizontal deflection signal from a horizontal deflection circuit; a vertical deflection detecting circuit for detecting a vertical deflection signal from a vertical deflection circuit; and a control circuit for determining whether the horizontal deflection signal and the vertical deflection signal are normal, and generating a predetermine control signal to run the DPMS operating unit in order to observe the conditions of horizontal/vertical synchronization signals continuously, and protect a CRT monitor independently from the horizontal/vertical synchronization input conditions.

Abstract: A method is provided for reducing a residual spot on a cathode ray tube when a power supply is turned off. The method is executed by applying a holding voltage being no less than the value of the voltage enabling to enhance the back raster luminance and a cut-off voltage, or a voltage of a lower value, to a second grid electrode while the anode voltage is lowered to a predetermined voltage value when the main power supply is turned off.

Abstract: A protective circuit and a signal processor for a three-CRT projection TV for preventing CRT burnout, deterioration of luminous characteristics, and damage to lenses by heat. Each CRT beam current detection circuit detects the beam current of each CRT. A state of the video image is predicted based on the detected beam current values and their duration. A microcomputer determines a control voltage for controlling the contrast based on the state of the video image, detected values, and their duration. The contrast is thus controlled by a control signal output to a video control circuit which controls the beam current.

Abstract: A kinescope video driver includes a series connection of a main cascode transistor coupled to a cathode of a cathode ray tube and a video signal amplifying transistor. A second cascode transistor is coupled between the main cascode transistor and the video signal amplifying transistor. The second transistor is coupled to the video signal amplifying transistor through a short wire conductor and to the main cascode transistor through a long wire conductor.

Abstract: A spot killer circuit for a CRT is capable of thoroughly removing any spot persistence and prevents damage to the fluorescent body of the CRT due to inaccurate horizontal and vertical deflection. When the power cord is unplugged, or when the display device is turned off (for example, via remote control key input), the bias voltage of the first grid G1 and the electric potential of the cathode are controlled so as to completely suppress any residual beam current flowing in the CRT. In the case of an inaccuracy (such as total failure) in either the horizontal deflection or the vertical deflection signals, the bias voltage of the first grid and the electric potential of the cathode are controlled to suppress the CRT beam current just as in the case of power shut off. This prevents damage of the fluorescent body in the CRT due to the inaccurate deflection operation.

Abstract: The invention relates to a method and arrangement for managing the power control of a monitor. In the solution according to the invention the monitor synchronizing signals are not monitored continuously in the OFF state but the monitoring is periodic. The solution according to the invention can be applied to all different kinds of display terminals and monitors.

Abstract: An automatic beam current limiting apparatus for limiting beam currents of R, G, and B colors separately without affecting the the CRT drive. In particular, the Average Picture Level (APL) of each of the R, G, and B color video signals at the preceding stage of a video power amplifier is detected and compared with a reference voltage. When the APL of the video signal is higher than the reference voltage, the amplitude of the video signal is controlled to limit the beam current driving the CRT. In addition, the G1 voltage, and G2 voltage may be compared with a reference voltage and a result calculated by the APL calculating circuit. When the result is higher than the reference voltage, the amplitude of the video signal is controlled to limit the beam current driving the CRT.

Abstract: An image display is disclosed, in which a reference signal is superimposed on image signal in a fly-back period for controlling the bias voltage on the cathode of the CRT or the reference signal or the bias voltage on the grid G2 of the CRT such as to make the beam current in the CRT cathode to be constant by detecting the beam current in the reference signal period, while also obtaining brightness control. The image display comprises a stub pulse generator 2 for providing a stub on the black level side more than the image signal pedestal level, and an adder 3 for superimposing the stub pulse on the image signal. It is possible to change the reference signal voltage level to be on the black level side more than the image signal pedestal level, extend the brightness range, and obtain back luster float-up.

Abstract: A display apparatus includes the switching unit for switching between an operating mode and a standby mode. The apparatus generates a picture on a display screen in the standby mode. The apparatus includes, for example a microphone for measuring a sound volume in the vicinity of the apparatus. The microphone is coupled to the picture-generating unit in order to change the picture in the standby mode in response to a change of the measured sound volume.

Abstract: The synchronization signal processing circuit of a monitor for protecting the cathode ray tube includes a rectifying unit for rectifying a synchronization signal supplied from the outside; a first inverting unit for inverting the rectified signal and generating a first inverted signal; a control unit for controlling the output of the first inverted signal according to the synchronization signal by being switched on; a second inverting unit for delaying the rectified signal for a predetermined time period, inverting the delayed rectified signal, and generating a second inverted signal; and a synchronization signal outputting unit for buffering the first and second inverted signals and applying the buffer signal to a microprocessor, a video signal processor and a deflection circuit respectively. Accordingly, even while there is no input from the keyboard for a certain time period, the fluorescent screen of the CRT can be protected since the point of the screen to which the video signal is injected changes.

Abstract: A system and method of compensating for the effects of aging of phosphors and faceplate upon color accuracy in cathode ray tubes, wherein beam current measurements are made upon individual cathodes of a cathode ray tube to sample the individual beam currents at periodic intervals. The sum-totals of the individual beam current measurements are then stored in a non-volatile memory location. Correction factors are calculated for both luminous efficiency degradation and for deviations in hue, based on the stored sum-total beam current measurements in combination with empirically-derived formulae. These correction factors are then used to calculate corrected tristimulus values X, Y, and Z. The corrected tristimulus values are used to calculate the amount of beam current necessary to compensate for color degradation of the cathode ray tube.

Abstract: An improved spot elimination circuit for preventing a spot from occurring on the screen of a cathode ray tube such as a monitor or television receiver at the instant that the deflection circuit is shut off. An input voltage is charged and discharged to supply a high voltage in negative polarity to a first grid of the cathode ray tube. The spot elimination circuit includes a flyback transformer having a separate turns portion additionally provided for generating a high voltage and utilizes the high voltage as an input to thereby supply a cut-off voltage to the first grid. Accordingly, the phosphor screen of the cathode ray tube is protected from excessive cathode luminance at a focused spot which can cause degradation of the screen.

Abstract: Dramatically lower power consumption of a video display to is achieved during standby mode. Using relatively simple sync-energy converting circuitry, the power supply can be switched on/off electronically, without the need to have the main power supply running and without an auxiliary supply. Power consumption of 0 W may thereby be achieved. In accordance with one embodiment of the invention, sync-signal energy is stored in a storage capacitor. During charging, the capacitor is decoupled from any load such that capacitor voltage will reach a peak voltage of the unloaded source signal. Charge and discharge cycles repeat continuously for so long as the power switch is turned off. This charging and discharging allows the display to be turned on using the power switch, even without the momentary presence of AC line voltage. A possible non-retriggable state is avoided using an RC time constant.

Abstract: A system and method achieve and maintain an accurate white point setting of a CRT display in a computing system. The CRT is initially calibrated by individually driving the individual color cathodes and by measuring tristimulus values and cathode beam current for each of the three primary colors. The tristimulus values are normalized by dividing each value by the beam current producing it, and the normalized values are then stored in a calibration memory contained in the display unit. A table of gamma values representing beam current as a function of video drive voltage is measured and also added to the calibration memory. Calibration of the display is implemented by driving the display controller with a white point value and calculating the cathode beam currents from the stored tristimulus values, required to produce an accurate CRT representation of the signal sent to the display controller.

Abstract: A method and apparatus for reducing power consumption by a display device includes monitoring time intervals between successive updates by video update circuitry and time intervals between successive uses by one or more user-interface devices, such as a mouse or keyboard. A first time-elapsed signal is generated if a predetermined time interval is exceeded between successive uses by the user-interface devices. A reset input to a first timer is connected to the user-interface devices to restart the timing with each use. A second time-elapsed signal is generated if the interval between successive video updates exceeds a second predetermined time period. Video updating resets the timer used to monitor the video update circuitry, but once the second time-elapsed signal has been initiated, a video update will not disable the signal. Rather, the second time-elapsed signal is latched until the use of a user-interface device.

Abstract: A video graphics generator 30 is provided for a video system such as an amusement machine which includes a video display device 18, user operable input devices 14, 16, 17 and a system controller 20 which is responsive to the user input devices and outputs video signals for driving the display device. The video graphics generator comprises a control unit responsive to an absence of operation of the user input means for a predetermined length of time to interrupt the video signals output by the system controller for at least a predetermined interval and to substitute alternative video signals for display on the video display device. An intermediate connector 27 for a standard interface between the system controller other elements of the video system can be used to sense signals for determining when to interrupt the normal video signals from the system controller.

Abstract: In order to reduce the effects of discontinuities at the edge of a picture and reduce erosion of the usable picture area caused by a filtering or interpolation operation, the edges of the picture are extrapolated prior to such an operation. This may be achieved by a circuit which receives an input line of active pixel data; forms from the input line a delayed line of the active pixel data; produces at least one additional start pixel data derived from a pixel data at or adjacent the start of the input line; produces at least one additional end pixel data derived from a pixel data at or adjacent the end of the input line; and forms an output sequence of pixel data by selecting for the output sequence the additional start pixel data, then at least part of the delayed line, and then the additional end pixel data. This circuit therefore performs zero-order (repeat) extrapolation at the beginning and end of each line.

Abstract: To avoid burn in a scanning cathode ray tube, the address of the scanning spot at each clock period is recorded in a memory. During each frame period, the logarithms of the number of occurrences of each address are fed to a peak detector. The peak value is used to determine a maximum allowable beam current for the next frame. In another embodiment, the number of occurrences of each address during a line period is monitored and if this number exceeds a given number the CRT is blanked.