Abstract: A compact color display tube is provided in which a modulated electron beam enters a repelling trajectory control field, formed between a mesh electrode and a planar electrode, at an acute angle .alpha.. The beam follows a parabolic trajectory and approaches a target electrode bearing bands of phosphor stripes at substantially the same angle. The mesh electrode, comprising a plurality of parallel conductors, is disposed adjacent to the target electrode. The conductors of the mesh electrode extend parallel to the stripes and are spaced at a pitch corresponding to the pitch of the repeating bands of phosphor stripes. The target electrode is held at a potential such that the electron beam passing through the space between a pair of the conductors is focused and deflected onto a phosphor line of the target. A colored picture can be produced using a single electron beam by a spot wobbling technique or by scanning each phosphor line sequentially.

Abstract: A channel plate with color selection electrodes and color phosphors for use as an image display screen in a color television tube. This is a division, of application Ser. No. 288,597, filed Sept. 13, 1972, now U.S. Pat. No. 3,860,849, Jan. 14, 1975.This invention relates to colour television display apparatus.In conventional colour television display tubes, complex problems of registration arise. Thus, for example, the shadow-mask tube (in spite of the added cost and complexity of its three gun system) involves accurate alignment between the holes in the shadow-mask and the tri-colour phosphor triads on the display screen. In the case of the Chromatron there is the problem of aligning the colour-selector grid with the phosphor stripes.

Abstract: An electronic solid state device comprising a layer in which the electrical conductivity is controlled by a plurality of isolated discrete regions distributed within the bulk of the layer and forming potential barriers with semi conductor material of the layer surrounding the discrete regions. Electrical charge is stored in the layer by the discrete regions and the charging is obtained by the application of a potential pulse across the discrete regions. In a preferred operational mode the charging potential is applied such that current conduction paths in the layer are blocked by the depletion regions associated with the potential barrier for applied interrogation potentials across the regions of substantially smaller magnitude than the charging pulse. The device may consist of an imaging device having high charges gain and particular embodiments described consist of an image intensifier, an imaging active photocathode and a target plate of a vidicon camera tube.

Abstract: A channel plate with color selection electrodes and color phosphors for use an an image display screen in a color television tube.This is a division of application Ser. No. 288,597 filed Sept. 13, 1972, now U.S. Pat. No. 3,860,849.

Abstract: A channel plate electron multiplier having channels which rapidly decrease in cross-section away from the input aperture and a conductive structure extending across the input aperture to flatten any fringing electrostatic field, resulting in an electrostatic field configuration which causes secondary emitted electrons to collide with the same side of the channel.

Abstract: A flat large-area photocathode intended for use in an intensifier tube is constructed so that a pre-determined potential gradient can be maintained across its surface in operation in order to simplify the electron-optical system of the intensifier. This is done by providing photoemissive material on an electrically resistive layer or sheet on a major surface of which is provided a series of spaced rings of electrically conductive material one inside the other. The spacings and widths of the rings are chosen so that, when a potential difference is applied between the center and the edge of the sheet or layer, the desired potential gradient is set up across the surface of the photocathode. The intensifier tube may be an x-ray image intensifier.