International Business Machines Corporation

John S Beeteson

Andrew Ramsay Knox

Christopher Carlo Pietrzak

Anthony Cyril Lowe

Shaun Carl Kerigan

David Sawdon

Kenneth George Smith

Andrew Ramsey Knox

Peter Beanlands

John Ulrich Knickerbocker

David Leaver

Frederick S Jackson

Adrian Mark Clitheroe

Brian L Holloway

Frank John Martin

Edward D Anwyl

Peter Martinez

Krzystof T Jarzebowski

Ken G Smith

Edward Trevor Shepherd

Griffith John Lewis

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.

Active correction technique for a magnetic matrix display

A magnetic matrix display device has a grid electrode in which differing first grid (G ) and second grid (G ) 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.

Grid electrodes formed on a polyimide substrate for a display device that comprises a permanent magnet

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.

Etched and formed extractor grid

A magnetic matrix display device has a grid electrode in which differing first grid (G,) and second grid (G,) 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.

Grid electrodes for a display device

An auto-stereoscopic display device comprises a plane viewing screen, a plane cathode, and a plane 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 phosphor layer is disposed between the screen and the magnet and having a plurality of pixels each corresponding to a different channel. Grid electrode means is disposed between the cathode and the magnet for selectively controlling flow of electrons from the cathode through each channel to the corresponding pixel in response to input video data. Deflection anode means is disposed on the side of the magnet remote from the cathode for sequentially deflecting, orthogonally to the columns, each electron beam to different parts of the corresponding pixel in response to an input video clock signal. A lenticular lens array is disposed between the phosphor layer and the screen and having a plurality of cylindrical lenses each corresponding to a different column of pixels.

Auto-stereoscopic display device and system

Raster demodulation apparatus for a raster-scanned cathode ray tube display comprises control means (,) for varying the shape of at least one scanned electron beam spot (,) in a direction perpendicular to scan lines of the raster. The control means (,) comprises an electro-magnet (,) for mounting on the neck of the cathode ray tube. The magnet (,) has eight pole pieces (,) spaced around the neck of the cathode ray tube (,). A winding (,) passes around each of the pole pieces (,) in succession in opposite directions so that, when an electrical current (I) is passed through the winding, adjacent pole pieces (,) around the neck of the cathode ray tube have different magnetic polarity to generate, within the neck of the cathode ray tube (,), a magnetic field in which magnetic lines of force (,) pass through the or each electron beam (,) only in a direction parallel to the scan lines of the raster.

Raster demodulation apparatus and method

An electron source comprises a permanent magnet having channels within the plate extending between opposite poles of the magnet. The internal surfaces of the channels are conductive. A cathode means is located at a first pole of the magnet, at one end of the channels. Each channel within the magnet has a plurality of perforations located on a surface of the permanent magnet, the surface extending between opposite poles of the magnet. A potential applied between the cathode and the conductive internal surfaces of the channels causes electrons to be received into the channels and each perforation forms electrons received from the cathode means into an electron beam for guidance towards a target.

Magnetic channel cathode

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.

Current sensing in vacuum electron devices

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.

Self stabilizing non-thermionic source for flat panel CRT displays

An electron source comprises a first permanent magnet having a first channel, extending between first and second poles of the magnet, the internal surfaces of the first channel being conductive. A cathode means is located in the first channel at a first pole of the magnet, a potential being applied between the cathode means and the conductive internal surfaces of the first channel causing electrons to be received into the first channel. A plurality of apertures is located on a wall of the first channel, the wall abutting a second permanent magnet having a plurality of second channels extending between first and second poles of the second magnet. The second pole of the second permanent magnet is adjacent to the aperture located on a wall of the first magnet such that electrons received into the first channel are distributed into the plurality of second channels.

Electron source having a plurality of magnetic channels

A photo-cathode electron source suitable for use in flat panel displays has an extractor grid means (,) 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 (,) of the photo-cathode means (,) by means of evaporation from the extractor grid (,).

Photo-cathode electron source having an extractor grid

A display system for displaying a visual image in response to a video signal (,), comprising; a liquid crystal display panel (,) divided into a plurality of addressable, variable brightness sections (,); address circuit (,) for generating a section address corresponding to a section in response to a timing signal (,); driver circuit (,) for varying the brightness of the section in response to a brightness signal (,) derived from the video signal (,); characterised in that the display system further comprises: a memory (,) for storing a predetermined correction signal (,) corresponding to the section; and control circuit (,) coupled to the driver circuit (,) for varying the brightness signal (,) to reduce brightness non-uniformities in the displayed image in response to the video signal (,) and the correction signal (,) in combination. The control circuit preferably includes a summing circuit for adding the correction signal to the video signal to produce a summed signal for determining the brightness signal. In another preferred embodiment the control circuit includes a voltage control circuit for varying the amplitude of the brightness signal in response to the correction signal.

Display system having section brightness control and method of operating system

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. The apertures are of varying cross-section in the vicinity of the supports such that localized variations in the emission of electrons by the cathode means caused by the one or more supports is compensated. The display also has one or more spacers between the screen and the magnet and anode means disposed on the surface of the magnet remote from the cathode for accelerating electrons through the channels. The anode means is of varying shape in the vicinity of the spacers such that localized variations in the electron beam shape and position caused by the one or more spacers is compensated.

Spacer, support, grid and anode design for a display device compensating for localized variations in the emission of electrons

A display system comprises a display screen and drive means for scanning a picture onto the display screen in response to a video signal. Image scanning apparatus in the display system comprises photo-detection means optically coupled to the display screen for generating an image signal on detection of any light from the scanned picture reflected back into the display screen by an external article and subsequently internally reflected within the display screen. Storage means stores the image signal detected by the photo-detection means.

Growing community of inventors

Skelmorlie, United Kingdom

John S Beeteson