摘要:
A colour display tube (10) which has a channel plate electron multiplier (22) for multiplying a low voltage, low current electron beam (18) and thereby obtaining an amplified output beam (60) for producing an image on a screen (24) formed of a plurality of different phosphors arranged as dots, each of which is surrounded by at least one ring. In order to form the output beam (60) into well defined dots and rings to obtain good colour purity, the source-to-screen distance of the output beam (60) is varied in a predertermined manner. A means for doing this comprises additional electrodes (50), (52) and (54) mounted on the output side of the electron multiplier (22).
摘要:
A colour cathode ray tube including a screen (16) comprising at least two sets of phosphor stripes luminescing in different primary colours. A channel plate electron multiplier (44) is mounted parallel to, but spaced from, the screen (16). The electron multiplier (44) comprises a stack of juxtaposed substantially planar apertured dynodes (DI to Dn) with the apertures therein aligned to form channels. An apertured extractor electrode (48) is mounted on the output side of the electron multiplier (44). Preferably two or more foraminous deflector electrodes (50, 52) are mounted on the extractor electrode. The apertures in the foraminous deflector electrodes (50, 52) have the same pitch as the channels of the electron multiplier but are offset laterally relative to each other and to the axes (A) of the channels by amounts which allow the emergent electron beam from each channel to pass through to the screen (16) without impinging upon the deflector electrodes (50, 52). By applying a potential difference between the deflector electrodes (50, 52) an electron beam emerging from its respective channel is deflected laterally onto a respective one of its associated group of phosphor stripes. The apertures in the deflector electrodes (50, 52) may be circular, elliptical or polygonal for example square, rectangular or hexagonal.
摘要:
An active matrix liquid crystal video display system comprises a display panel (10) having a row and column matrix array of liquid crystal picture elements (12) with respective controlling switching devices (11) for displaying video information such as TV pictures, and a drive circuit for driving the picture elements to which a video, e.g. TV, signal of given field frequency is supplied (25). In order to reduce the response time of the picture elements, the display panel is driven at a field rate higher than that of the supplied video signal. To this end, the drive circuit includes a field rate conversion circuit (28,30,31,32) comprising field stores.
摘要:
A colour cathode ray tube including a screen (16) comprising at least two sets of phosphor stripes luminescing in different primary colours. A channel plate electron multiplier (44) is mounted parallel to, but spaced from, the screen (16). The electron multiplier (44) comprises a stack of juxtaposed substantially planar apertured dynodes (DI to Dn) with the apertures therein aligned to form channels. An apertured extractor electrode (48) is mounted on the output side of the electron multiplier (44). Preferably two or more foraminous deflector electrodes (50, 52) are mounted on the extractor electrode. The apertures in the foraminous deflector electrodes (50, 52) have the same pitch as the channels of the electron multiplier but are offset laterally relative to each other and to the axes (A) of the channels by amounts which allow the emergent electron beam from each channel to pass through to the screen (16) without impinging upon the deflector electrodes (50, 52). By applying a potential difference between the deflector electrodes (50, 52) an electron beam emerging from its respective channel is deflected laterally onto a respective one of its associated group of phosphor stripes. The apertures in the deflector electrodes (50, 52) may be circular, elliptical or polygonal for example square, rectangular or hexagonal.
摘要:
A cathode ray tube comprising a channel plate electron multiplier structure disposed between a source of electrons and a cathodoluminescent screen, the electron multiplier comprising a stack of n apertured dynodes. The dynodes are separated from each other and are arranged in cascade with the apertures in adjacent dynodes aligned to form channels. When designing dynodes an aspect ratio is generally adopted that the axial length of the aperture, which length corresponds to the thickness of the dynode, is the same as the input and output cross-sections of the apertures, which are of re-entrant form. If this aspect ratio is maintained for high resolution dynodes then the dynodes would be so thin as to make them difficult to handle. This problem is mitigated by changing the axial profile of the aperture in at least the second to the (n-1)th dynodes such that it comprises a re-entrant portion (24) within the thickness of the dynode (10) with the axially spaced ends (26,28) of the re-entrant portion (24) being spaced from the respective opposite surfaces of the dynode (10) by a convergent or cylindrical input portion (20) and a divergent or cylindrical output portion (22). i The axial length of the re-entrant portion (24) corres-[ponds substantially to the cross-section of the input (or ;output) portion at a point where it communicates with the re-entrant portion (24).