Abstract:
A multi-beam color index cathode ray tube (CRT) includes vertically spaced, horizontal phosphor stripes on the inner surface of its display screen. The parallel phosphor bands are arranged in groups of three, with each phosphor stripe in a group providing a respective one of the three primary colors of red, green and blue. An electron gun directs three electron beams onto the display screen, with the three electron beams deflected over the display screen in unison in a raster pattern. The three electron beams are focused in the form of three spots on the display screen, with each spot coincident with a respective horizontal phosphor stripe of a given color. The intensity of each electron beam is independently modulated as it sweeps across the width of the display screen by a respective color video signal in accordance with the displayed image. The three electron beams are each provided with a horizontally elongated cross section, with convergence of the beams provided by a plurality of multi-pole adjustable magnets. By horizontally elongating and vertically offsetting the beams, the vertical spacing between the electron beams as well as between the horizontal phosphor stripes may be reduced for improved video image resolution. The closely spaced electron beams may be focused with a conventional main focusing lens employing a common beam-passing aperture, with electron beam alignment with the horizontal phosphor stripes provided via a beam responsive UV emitter/sensor combination and feedback control arrangement.
Abstract:
Described is a beam index type color cathode ray tube in which at least one of tricolor phosphor stripes, that is the red, blue and green stripes, is different in width from the other color phosphor stripes, and m index stripes are associated with n sets or triplets of the color phosphor stripes. The widthwise center-to-center distance between the adjoining color phosphor stripes is set to a constant value. Each index stripe is of a width lesser than the width of the guard band provided between adjoining ones of the color phosphor stripes, and is provided at the widthwise center of the associated guard band. The arrangement provides index signals of sufficient intensity, while assuring a positive color switching.
Abstract:
A color cathode ray tube includes an automatic convergence unit employing index elements on the reverse surface of a color-selective electrode. The paste used for forming the index elements has a composition consisting essentially of index phosphors, an inorganic adhesive and water to assure the adhesive force of the index elements onto the color selective electrode to prevent peeling of the index elements while facilitating the coating operation for formation of the index elements.
Abstract:
The target of a CRT comprises a single crystal substrate (e.g., YAG) on which are formed a plurality of color stripe triads of epitaxial material. Each stripe triad has three epitaxial layers in a staircase geometry and is overlayed with a metal stripe. The metal stripes are the fingers of a pair of interdigitated electrodes. A single e-beam scans the stripes horizontally, and a sequence of current pulses generated in the electrodes precisely defines the horizontal position of the beam relative to the triads. This information is used to precisely time the beam modulation for introducing color signals. The CRT is particularly suited to miniaturization and application in projection systems.
Abstract:
A beam-indexing color picture tube includes a gun for producing an electron beam that scans across a screen of the tube and a plurality of index phosphor stripes provided on the screen for emitting near-ultraviolet index lights. The near-ultraviolet index lights are transmitted through a window formed in the tube to a detector. The detector is formed by a planar fluorescent collector doped with fluorescent material for absorbing the near-ultraviolet index lights, and at the same time, generating secondary index lights having different wavelength than that of the near-ultraviolet index lights. A silicon p-i-n photodiode is mounted on the planar fluorescent collector for detecting the secondary index lights and for generating electrical signal representing the near-ultraviolet index lights.
Abstract:
In shadow mask color cathode-ray tube apparatus, the shadow mask is provided with slits or rows of slots extending from side to side of the mask and a line raster is constrained so that the lines of the raster are colinear with the slits, there being just one slit to each line of the raster. Open loop control may be used to achieve colinearity, but closed loop control is preferred. Beam position signals may be drived from the shadow mask by sensing secondary emission from different phosphors on the gun side of the mask or be sensing currents generated in the mask. In the preferred embodiment, the beams are dithered as they traverse the raster and the difference in the currents generated by a beam at the mask and at the conductive layer at the tube screen is detected. The first fundamental of the difference current indicates by its amplitude and phase the amount and direction of the misregistration of a beam and a slit. Different beams are distinguished by frequency multiplexing.
Abstract:
Beam-index cathode ray tubes are depicted in combination with elongated strip-like and coiled light pipe-scintillators. Penetrating radiation which impinges upon the side walls of the elongated light pipe-scintillator creates scintillations in the interior region thereof. These scintillations are in the optical frequency range and are accumulated in strength as they travel through the light pipe. They emerge at exit terminals in concentrated form. The concentrated optical scintillations are used for beam indexing purposes in cathode ray tubes including those with multicolor producing target screens. Single, dual, and triple index signal configurations are described.