Abstract: An improved orientation system includes a lens pre-distorting an image generated by imaging apparatus such that a non-linearity, the degree of which is dependent on the off-axis distance of an imaged object, is generated so as to increase the strength of a signal indicating said non-linearity.

Abstract: A matrix addressed display device having a cathode means and grid electrode means comprising an orthogonal array of parallel row conductors and parallel column conductors in which means are providing for selectively applying cut-off and gain correction information to the row conductors and the column conductors. The cut-off and gain correction information may be applied so as to affect all of the display area equally and correct for warm up drift, or it may be applied so as to correct for the effect of a discrete number of hot cathode filaments being used or it may be applied on a pixel by pixel basis.

Abstract: An improved head-up display enables a user to view a light emitting display and an ambient environment simultaneously. The improved display comprises a light-transmissive block allowing the transmission of light from the ambient environment to the user's eye through the block from a first surface to a second surface opposing the first surface. A light emitting display is located on a third surface of the block, the third surface being substantially perpendicular to the first and second surfaces. A beam splitter has a plane surface arranged at substantially 45 degrees to the first and second surfaces, so as to reflect light from the light emitting display through the second surface. A shutter is located on the first surface and is adapted to block the transmission of light from the ambient environment to the user's eye. This provides a dark background for the light emitting display.

Abstract: An improved orientation system includes a lens pre-distorting an image generated by imaging apparatus such that a non-linearity, the degree of which is dependent on the off-axis distance of an imaged object, is generated so as to increase the strength of a signal indicating said non-linearity.

Abstract: A magnetic matrix display device has a grid electrode in which differing first grid (G1) and second grid (G2) apertures are used. A sensor element and a second grid electrode are combined as a single structure. Other aspects of the invention relate to a deflection anode having reduced capacitance, the use of a polyimide coating for the grid electrodes, the use of a compliant mounting and adjustment for a grid assembly and the provision of an illuminated border on a magnetic matrix display.

Abstract: A client computer system is suitable for connection to a data processing network having a controlling system. The controlling system is operable to issue a wake-up request to the client computer system. The wake-up request is issued by means of a wireless connection between the controlling system and the client computer system. The client computer system, on receipt of the wake-up request, powers itself on so as to allow normal operation of the client computer system.

Abstract: A computer system includes a communication means for connection to a remote computer and a position determination system for determining the physical position of the computer system. The communications means receives a request from the remote computer for the computer system to provide the physical position of the computer to the remote computer system via the communications means. The request from the remote computer may originate because the computer system has been stolen or mislaid by a user or it may originate because the computer system has inadvertently been allocated the same network identifier as another computer and the physical location of the computer system needs to be known so that the network identifier can be changed.

Abstract: A magnetic matrix display device has a grid electrode in which differing first grid (G1) and second grid (G2) apertures are used. A sensor element and a second grid electrode are combined as a single structure. Other aspects of the invention relate to a deflection anode having reduced capacitance, the use of a polyimide coating for the grid electrodes, the use of a compliant mounting and adjustment for a grid assembly and the provision of an illuminated border on a magnetic matrix display.

Abstract: An electron source comprises at least one cathode means, and at least one extractor grid which is used to extract electrons from the cathode means. The extractor grid is a substantially planar sheet having at least one aperture and also has at least one spacing member for spacing the extractor grid at a constant, predetermined spacing from the cathode. Each of the spacing members are formed by removing material around a substantial portion of the periphery of the aperture and folding the remaining portion of the periphery of the aperture at substantially a right angle to the planar sheet.

Abstract: A magnetic matrix display device has a grid electrode in which differing first grid (G1) and second grid (G2) apertures are used. A sensor element and a second grid electrode are combined as a single structure. Other aspects of the invention relate to a deflection anode having reduced capacitance, the use of a polyimide coating for the grid electrodes, the use of a compliant mounting and adjustment for a grid assembly and the provision of an illuminated border on a magnetic matrix display.

Abstract: A metal/ferrite laminate magnet has perforations forming apertures in the magnet. The magnet is formed of outside metal plates surrounding a sandwich of two layers of ferrite material. The outside metal plates allow the perforations to be made in the magnet before sintering of the magnet and maintain the alignment of the holes during sintering. The metal plates also provide the magnet with mechanical robustness and rigidity and prevent cracking occurring between adjacent apertures.

Abstract: A vacuum electron device comprises an evacuated envelope containing a cathode for supplying electrons to form an electron beam, an anode spaced from the cathode for receiving the electron beam, and a sensor electrode located between the cathode and the anode.

Abstract: A vacuum electron device comprises an evacuated envelope containing a cathode for supplying electrons to form an electron beam, an anode spaced from the cathode for receiving the electron beam, and a sensor electrode located between the cathode and the anode.

Abstract: A virtual non-thermionic cathode has the position of a space charge cloud associated with it fixed by the geometry of a fixed insulating layer. The layer can be made to accurate dimensions and hence the cathode to control grid dimension can be accurately controlled and will not change as a result of any mechanical, electrical or physical changes in the construction. The fixed insulating layer is located on a surface of the control grid facing the cathode. A space charge layer is built up on the surface of the insulating layer facing the cathode, and thus emission from the cathode is stabilized.

Abstract: A photo-cathode electron source suitable for use in flat panel displays has an extractor grid means (104) maintained, in use, at a positive potential with respect to the photo-cathode surface. The extractor grid may be used as a carrier for unfired photoemissive material which forms the emission surface of the photo-cathode. The material is deposited on the surface (103) of the photo-cathode means (102) by means of evaporation from the extractor grid (104).

Abstract: A display device comprises a substrate, cathode means for emitting electrons, a permanent magnet and one or more supports between the substrate and the magnet. A two dimensional array of channels extends between opposite poles of the magnet, the magnet generating, in each channel, a magnetic field for forming electrons from the cathode means into an electron beam. A screen receives an electron beam from each channel, the screen having a phosphor coating facing the side of the magnet remote from the cathode, the phosphor coating comprising a plurality of pixels each corresponding to a different channel. Grid electrode means is disposed between the cathode means and the magnet for controlling flow of electrons from the cathode means into each channel, the grid electrode means having a plurality of apertures, each aperture corresponding to one of the channels.

Abstract: Area cathode device for generating free electrons in a first evacuated chamber comprises a back plate; a silica glass substrate peripherally sealed to the back plate to produce a second chamber; a gas contained in the second chamber; a layer of photo-sensitive material disposed on the surface of the substrate external to the first chamber; a cathode phosphor layer disposed between the back plate and the substrate; and a pair of electrodes facing each other from opposite sides of the second chamber for energizing the gas to generate a plasma for exciting the cathode phosphor layer to generate light energy for producing electron emissions from the photo-sensitive material.

Abstract: A display device comprises a cathode means for emitting electrons and a permanent magnet having a two dimensional array of channels extending between opposite poles of the magnet. The magnet generates, in each channel, a magnetic field for forming electrons from the cathode means into an electron beam. A screen receives an electron beam from each channel, the screen having a phosphor coating facing the side of the magnet remote from the cathode, the phosphor coating comprising a plurality of areas, each area being capable of illumination, at least one of the areas being capable of illumination by a plurality of the electron beams. 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 comprising a plurality of elements each element corresponding to a different area of the phosphor capable of illumination.

Abstract: A display device includes 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 comprises a plurality of pixels each corresponding to a different channel. A grid electrode is disposed between the cathode and the magnet for controlling flow of electrons from the cathode into each channel. A deflection sequentially addresses the electron beam from each channel to each pixel of the corresponding group. Rotational alignment APPARATUS aligns electron beams from the channels with corresponding pixels of the phosphor coating.

Abstract: A metal/ferrite laminate magnet has perforations forming apertures in the magnet. The magnet is formed of outside metal plates surrounding a sandwich of two layers of ferrite material. The outside metal plates allow the perforations to be made in the magnet before sintering of the magnet and maintain the alignment of the holes during sintering. The metal plates also provide the magnet with mechanical robustness and rigidity and prevent cracking occurring between adjacent apertures.