Abstract: A display system for displaying a visual image in response to a video signal (10,34), comprising; a liquid crystal display panel (1) divided into a plurality of addressable, variable brightness sections (5); address circuit (6) for generating a section address corresponding to a section in response to a timing signal (11); driver circuit (7,8) for varying the brightness of the section in response to a brightness signal (14,15) derived from the video signal (10,34); characterised in that the display system further comprises: a memory (36) for storing a predetermined correction signal (35) corresponding to the section; and control circuit (31) coupled to the driver circuit (7,8) for varying the brightness signal (14,15) to reduce brightness non-uniformities in the displayed image in response to the video signal (34) and the correction signal (35) in combination.

Abstract: A liquid crystal display 10 is backlit by more than one light source 20 which is operated independently. Selective usage of the light sources extends the useful operating time of batteries when the liquid crystal display is used with a portable computer system.

Abstract: A cathode ray tube display having reduced electric field emissions comprising a cathode ray tube 100, an element 200 for detecting modulations in the final anode voltage of the CRT, the signal not being directly dependent on the deflection driving means 115. A matching network 205 provides phase and gain correction to the signal from element 200, amplification means 210 receives the signal from network 205 and an emission means 215 radiates a cancelling electric field dependent on the modulations detected by said element 200.

Abstract: A method and apparatus for bonding faceplates 10 to visual display unit (VDU) screens 20 is described. Adhesive material 170 is dispensed between the faceplate and the VDU and is selectively cured from the center outwards.

Abstract: A conductive coating on the front surface of the display screen is used to determine the position of an object, such as a user's finger, touching the screen. Sensors at the edge of the conductive coating detect changes in the level of the ambient field pickup when the user's finger touches the display screen. The conductive coating may optionally be divided into blocks with separate connections to each block, or may have a resistivity profile so as to allow full X and Y co-ordinate determination of the position of the finger. Also, optionally, a stylus generating an electromagnetic field when in contact with the display may be used in place of the finger.

Abstract: An electrical appliance comprises a power supply cable (70) having a first conductor (200) surrounded by a second conductor (210) for supplying electrical power to the appliance from a domestic electricity mains supply, and a connector (490) connected to cable for detachably connecting the conductors of the cable to first and second voltage signals of the electricity mains supply. In operation, the second conductor (210) is connected to the lower of the voltage signals. The second conductor (210) thus acts as a shield in opposition to electric fields radiating from the cable. The shield improves in efficiency as the lower mains voltage signal approaches Ground potential.

Abstract: This specification concerns cathode ray tube display apparatus comprises a cathode ray tube display screen (10). A beam generator (60,30) is provided for generating at least one electron beam in the cathode ray tube display screen (10) to produce a video image. Also provided is a line timebase circuit (40) for generating a line deflection signal to sequentially address the or each electron beam to successive pixels on the screen (10) in a line of a raster, and a frame timebase circuit (50) for generating an alternating frame deflection signal for sequentially addressing the or each electron beam to successive lines of the raster. The apparatus further comprises a standby circuit (110) connected to the line and frame timebase circuits (40,50).

Abstract: A color cathode ray tube display apparatus is provided with compensation for errors due to interfering magnetic fields in which a deflection yoke causes the electron beams to raster scan across the tube, a convergence assembly on the neck of the cathode ray tube adjusting the beam convergence. Errors in the waveforms suppied to the radial convergence assembly are caused by high frequency magnetic field coupling between the yoke and the convergence assembly via the internal magnetic structure 7 of the cathode ray tube. A compensating coil 11, placed adjacent the convergence coil unit 12, 16 supplies compensating current through resistor 20 to the amplifier 15 driving the convergence coil unit, thus avoiding a fringe on the left-hand side of the screen. Alternatively, compensating current can be derived from the line flyback pulse or the logic signal initiating line flyback.