Abstract: A data processing system is disclosed, which includes a system unit, a display device for displaying data generated by the system unit, data communication means for communicating display data between the display device and the system unit, a peripheral device, and peripheral communication means for communicating data between the peripheral device and the system unit. In accordance with the present invention, data is communicated between the system unit and the peripheral device via the display device. Data is transferred between the display device and the peripheral device utilizing a wireless communication link, thereby eliminating the problems associated with electrical cables. In a preferred embodiment of the present invention, the wireless communication link includes a first transceiver means located in the display device and a second transceiver means located in a peripheral device. In a first embodiment, the first and second transceiver means comprise infrared transceivers.

Abstract: A display device comprises a cathode and a permanent magnet. A two dimensional array of rows and columns of channels extends between opposite poles of the magnet for receiving electrons from the cathode. A screen has a plurality of phosphor pixels each corresponding to a different channel and each comprising a plurality of sub-pixels facing the side of the magnet remote from the cathode. Grid electrode means is disposed between the cathode means and the magnet. A plurality of pairs of anodes are disposed between the magnet and the screen and extending parallel to the columns of channels. Each pair corresponds to a different column of channels and each pair has first and second anodes extending along opposite sides of the corresponding column of channels. Address means supplies control signals to the grid electrode means to selectively control flow of electrons from the cathode through each channel to the corresponding pixel.

Abstract: Cathode ray tube display apparatus comprises a cathode ray display tube (210) in which an electron beam spot is scanned in a raster pattern to produce an output image. Drive means (200) generates drive voltages on the focus electrode, first and second grid electrodes, and a cathode of the cathode ray tube to generate the electron beam spot in the cathode ray tube. Spot size control means (120) simultaneously varyies, in response to a spot control signal, the voltages generated on the focus electrode, first and second gird electrodes and the cathode by the drive means to vary the size of the electron beam spot in the cathode ray tube.

Abstract: Display apparatus comprises a display screen. Drive means generates an image on the display screen in response to a video signal input from an external video source. The drive means comprises a memory for storing a gamma value and gamma correction means for modifying the input video signal as a function of a gamma value. Gamma variation means permits adjustment or the gamma value stored in the memory in response to a control signal input.

Abstract: Display apparatus comprises a display screen and drive means for generating an image on the display screen in response to a video signal input from an external video source. The drive means comprises gamma measurement means having a test signal generator for generating a test signal to produce a test image on the display screen, and output detection means for generating a sense signal as a function of the test image produced on the display screen.

Abstract: A method of bonding faceplates (20) to VDU screens is provided in which an adhesive material is dispensed (80) onto a surface of either the faceplate or the VDU (40), the faceplate and the VDU are brought together (90) to force the adhesive material outwards to fill the gap between the surfaces, and the adhesive material layer (41) which is formed is then cured. In a first curing step (100), curing is carried out around the edges of the faceplate to form a seal around the edges. This first step may be carried out in a dedicated positioning tool. A later curing step (120) ensures that all of the adhesive material layer is eventually cured. Positioning (90) in the dedicated tool may use specific reference points on the faceplate and the VDU rather than relying on physical spacers, and may be carried out under servo control of a system for detecting the onset of undesirable gas entrapment conditions within the adhesive layer.

Abstract: An electron source comprises cathode means and a permanent magnet. A plurality of channels disposed in the magnet in a two dimensional array of rows and columns and extending between opposite poles of the magnet. The magnet generates, in each channel, a magnetic field which forms electrons received from the cathode means into an electron beam for guidance towards a target. Grid electrode means are disposed between the cathode means and the magnet for controlling flow of electrons from the cathode means into each channel. The grid electrode means comprises a plurality of parallel row conductors and a plurality of parallel column conductors arranged orthogonally to the row conductors. Each channel is located at a different intersection of a row conductor and a column conductor. Electric field isolation means reduces leakage of electric fields from each intersection.

Abstract: A display device having a cathode for emitting electrons and a permanent magnet. A two dimensional array of channels extends between opposite poles of the magnet. The magnet generates, in each channel, a magnetic field for forming electrons from the cathode into an electron beam. An electrode grid is disposed between the cathode and the magnet for controlling flow of electrons from the cathode into each channel. A screen has a phosphor coating having a plurality of groups of adjacent pixels facing the side of the magnet remote from the cathode. Each group corresponds to a different channel. A deflector sequentially addresses the electron beam from each channel to each pixel of the corresponding group.

Abstract: A display device having a cathode for emitting electrons and a permanent magnet. A two dimensional array of channels extends between opposite poles of the magnet. The magnet generates, in each channel, a magnetic field for forming electrons from the cathode into an electron beam. A screen receives an electron beam from each channel. The screen has a phosphor coating facing the side of the magnet remote from the cathode. The phosphor coating having a plurality of pixels each corresponding to a different channel and each having a plurality of different color sub-pixels. An electrode grid is disposed between the cathode and the magnet for controlling flow of electrons from the cathode into each channel.

Abstract: A Moire interference detection apparatus for a raster-scanned cathode ray tube display is provided. The apparatus comprises a band-pass filter for generating an output signal in response to a signal indicative of the pixel frequency of a displayed image in a direction of raster scan falling within the pass band of the filter. Control means varies the center frequency of the pass band of the filter in dependence on an active video period of the image in said direction of raster scan, the spacing of adjacent phosphor elements of the cathode ray display tube of the display in said direction of raster scan, and the scan size in said direction of raster scan.

Abstract: A display comprising a cathode ray display tube (1) having an electromagnetic deflection yoke (2) is described. A pair of first deflection coils (7,6) are located symmetrically about the longitudinal axis of the tube (1) on opposite sides of the yoke (2) for producing within the tube (1) a first magnetic deflection field. A pair of second deflection coils (8,20) are similarly located symmetrically about the longitudinal axis on opposite sides of the yoke (2) for producing within the lube (1) a second magnetic deflection field at right angles to the first deflection field. The display is further provided with a pair of first cancellation coils (4,3) connected to the first deflection coils (7,6) for producing a first cancellation field which tends to cancel a first stray field produced by the first deflection coils (7,6). Support means (10,11) secure the first cancellation coils symmetrically about the longitudinal axis.

Abstract: A method of bonding faceplates (20) to VDU screens is provided in which an adhesive material is dispensed (80) onto a surface of either the faceplate or the VDU (40), the faceplate and the VDU are brought together (90) to force the adhesive material outwards to fill the gap between the surfaces, and the adhesive material layer (41) which is formed is then cured. In a first curing step (100), curing is carried out around the edges of the faceplate to form a seal around the edges. This first step may be carried out in a dedicated positioning tool. A later curing step (120) ensures that all of the adhesive material layer is eventually cured. Positioning (90) in the dedicated tool may use specific reference points on the faceplate and the VDU rather than relying on physical spacers, and may be carried out under servo control of a system for detecting the onset of undesirable gas entrapment conditions within the adhesive layer.

Abstract: Display apparatus comprises a display screen (400) and a drive circuit (401) connected to the display screen (400) to generate an image on the display screen (400) in response to an input video signal (R,G,B). A timer (405) generates a count in response to a clock signal. A detector (403,404,402) also receives the input video signal and resets the timer (405) on detection of a change in image content between successive frames of the input video signal (R,G,B). Control means (402) is connected to the timer (405) and to the drive circuit (401) for at least partially disabling the drive circuit (401) in response to the count stored in the timer (405) exceeding a predetermined threshold.

Abstract: A display comprising a cathode ray display tube (1) having an electromagnetic deflection yoke (2) is described. A pair of first deflection coils (7,6) are located symmetrically about the longitudinal axis of the tube (1) on opposite sides of the yoke (2) for producing within the tube (1) a first magnetic deflection field. A pair of second deflection coils (8,20) are similarly located symmetrically about the longitudinal axis on opposite sides of the yoke (2) for producing within the tube (1) a second magnetic deflection field at right angles to the first deflection field. The display is further provided with a pair of first cancellation coils (4,3) connected to the first deflection coils (7,6) for producing a first cancellation field which tends to cancel a first stray field produced by the first deflection coils (7,6). Support means (10,11) secure the first cancellation coils symmetrically about the longitudinal axis.

Abstract: An electric field cancellation system comprises a sensor (30) for generating an input signal (I) indicative of an unwanted electric field (E) radiating from a source (3), a variable gain amplifier (5) for amplifying the input signal (I) to produce an output signal (O), a radiator for generating a cancellation electric field (C) in anti-phase to the unwanted field (E) in response to the output signal (O) to at least partially cancel the unwanted field (E), feedback means (10) for generating an error signal (F) indicative of tile difference between the cancellation field (C) and the unwanted field (E), and control means (40) for varying the gain of the amplifier (4) to vary the output signal (O) in response to the error signal (F).

Abstract: The present electrical apparatus comprises an antenna for directing towards an electric field source to detect the electric field (E) to be reduced. The antenna is connected to amplifier for generating an output signal in response to an input signal from the antenna. The output signal is in anti-phase to the input signal. A radiator is connected to the amplifier for radiating a cancelling electric field (E') in anti-phase to the electric field (E) from the source in response to the output signal from the amplifier to at least partially cancel reduce the electric field from the source. The antenna, when directed towards the source, is positioned relative to the radiator and the source to detect both the cancelling electric field (E') from the radiator and the electric field (E) from the source. The input signal produced by the antenna is thus derived from the sum of the electric field (E) to be reduced from the source and the cancelling electric field (E') from the radiator.

Abstract: A method of bonding faceplates (20) to VDU screens is provided in which an adhesive material is dispensed (80) onto a surface of either the faceplate or the VDU (40), the faceplate and the VDU are brought together (90) to force the adhesive material outwards to fill the gap between the surfaces, and the adhesive material layer (41) which is formed is then cured. In a first curing step (100), curing is carried out around the edges of the faceplate to form a seal around the edges. This first step may be carried out in a dedicated positioning tool. A later curing step (120) ensures that all of the adhesive material layer is eventually cured. Positioning (90) in the dedicated tool may use specific reference points on the faceplate and the VDU rather than relying on physical spacers, and may be carried out under servo control of a system for detecting the onset of undesirable gas entrapment conditions within the adhesive layer.