Thomson Consumer Electronics Inc.

Rca Inc.

George M Ehemann, Jr

Edward Richard Garrity, Jr

Richard LaPeruta, Jr

Pabitra Datta

Eugene Samuel Poliniak

Istvan Gorog

Peter M Ritt

John J Moscony

Harry R Stork

Brian Thomas Collins

Robert A Duschl

Thomas L Chase

The present invention relates to a method of electrophotographically manufacturing a phosphor screen 22 comprising a multiplicity of color-emitting screen elements arranged in color groups on an interior surface of a faceplate panel 12 of a color CRT 10. The multiplicity of screen elements is exposed to a source 35 of UV radiation to stimulate the screen elements to emission. The emission from the screen elements is utilized to determine, on a pixel-by-pixel basis, a first emission characteristic of each color group of screen elements. Then, a subsequent manufacturing step (58, 62) is performed that affects the screen elements, and the multiplicity of screen elements is re-exposed to the source of UV radiation to stimulate the screen elements to emission. The resultant emission is utilized to determine, on a pixel-by-pixel basis, a second emission characteristic from each color group of screen elements. The second emission and first emission characteristics are then compared on a pixel-by-pixel basis (60, 64).

Method of manufacturing a phosphor screen for a CRT

The invention relates to a method of determining the quality of an aluminized, luminescent screen 22 for a CRT 10. The luminescent screen 22 is disposed on an interior surface of a faceplate panel 12 with an aluminum layer 23 overlying the screen. The method includes the steps of: exposing the aluminum layer to ultraviolet radiation; and measuring the luminescence emitted by the screen through the aluminum layer.

Method of determining the quality of an aluminized, luminescent screen

The invention relates to a method for determining the thickness of an OPC layer 24 that is strongly absorptive to light at a first wavelength and substantially transmissive to light at a second wavelength. According to the method, the OPC layer is illuminated with light from an array 34 of fluorescent lamps 36 and the light transmitted through the layer is incident on a first filter 42 that is transmissive to light of the first wavelength. A first light intensity pattern transmitted through the first filter is sensed and stored in a first memory frame. Then OPC layer is illuminated again with light and the light transmitted through the layer is incident on a second filter 44 transmissive to light of the second wavelength. A second light intensity pattern transmitted through the second filter is sensed and stored in a second memory frame. The ratio of the first light intensity pattern and the second light intensity pattern is determined and utilized to calculate the thickness of the layer. An apparatus for practicing the method utilizes a CCD camera 38 as a light sensor which receives the filtered light. A computer 50 divides the first memory frame by the second memory frame to calculate the thickness of the OPC layer. A suitable display 52 provides a contour plot of the thickness of the OPC layer.

Method and apparatus for determining thickness of an OPC layer on a CRT

In accordance with the present invention, a method of electro-photographically manufacturing a luminescent screen assembly on an interior surface of a faceplate panel 12 for a color CRT 10 includes the steps of coating the interior surface of the faceplate panel with a volatilizable, organic conductive solution to form an organic conductive (OC) layer 32, and overcoating the OC layer with a volatilizable, organic photoconductive solution to form an organic photoconductive (OPC) layer 34. The step of overcoating the OC layer to form the OPC layer is improved by the substeps of: grounding the OC layer; providing an organic photoconductive (OPC) solution comprising a resin, an electron donor material and electron acceptor material, and a suitable solvent; and spraying electrostatically-charged droplets of the OPC solution onto the OC layer, with at least one electrostatic spray gun 47, to provide an OPC layer, having uniform thickness, overlying the OC layer.

CRT electrophotographic screening method using an organic

A luminescent screen assembly for a CRT is made by first coating the interior surface of a faceplate panel with a photoconductive layer which overlies a conductive layer. A multiplicity of red-, green- and blue-emitting phosphor screen elements are then deposited in color groups, in a cyclic order, onto the interior surface of the panel. A negative charge is then established on the photoconductive layer. The charge is weakened in the areas where the photoconductive layer underlies the phosphor screen elements, but unaffected in the open areas separating the phosphor screen elements. The charged, open areas of the photoconductive layer are discharged by flood illumination and reversal developed by depositing thereon particles of light-absorptive matrix material having a triboelectric charge of the same polarity as the charge established on the photoconductive layer. The novel process provides a high opacity matrix.

Method of electrophotographically manufacturing a screen assembly for a

A luminescent screen assembly for a CRT is made by first coating the interior surface of a faceplate panel with a photoconductive layer which overlies a conductive layer. A multiplicity of red-, green- and blue-emitting phosphor screen elements are then deposited in color groups, in a cyclic order, onto the interior surface of the panel. A substantially uniform charge is established on the photoconductive layer. The charge is weakened in the areas where the photoconductive layer underlies the phosphor screen elements, but unaffected in the open areas separating the phosphor screen elements. The charged open areas of the photoconductive layer are directly developed by depositing thereon particles of light-absorptive matrix material having a triboelectric charge opposite in polarity to the charge established on the photoconductive layer. The attenuation of the charge on the photoconductive layer by the overlying phosphor materials produces a sufficient voltage contrast with the charge on the open areas of the photoconductive layer to provide a high opacity matrix.

Method of forming a matrix for an electrophotographically manufactured

Method comprises producing a pattern of alternate light and dark areas along a particular path on the back surface of a viewing window, scanning the image of the pattern along the projected path with a photodetector in such manner as to produce an alternating image signal, and then deriving the value of MTF (modulation transfer function) from the image signal. The viewability of images transmitted through the viewing window can be then characterized by a combination of values of MTF and SR (specular reflection).

Method for determining the MTF of a viewing window

Method for photodepositing a CRT screen structure including projecting a light field through an IC filter having tailored light transmission, through a photographic master and incident upon a photosensitive layer. The IC filter is a half-tone comprising an array of discrete spaced-apart opaque elements of predetermined sizes arranged along parallel spaced-apart lines.

Photodepositing a CRT screen structure using discrete-element optical

A method for printing a viewing-screen structure including projecting, at least three times, a light field from a light source, through a lens, an optical filter and incident upon a photosensitive layer. During one of the projecting steps, the light source and the nominal axes of the light source, the lens, the filter and the layer (which are substantially parallel to one another) are aligned along a common axis. During each of the other two projecting steps, the light source and the axis of the lens remain aligned along the common axis, and the axes of the filter and the layer are offset prescribed distances on opposite sides of the common axis.

Growing community of inventors

Lancaster, PA, United States of America

George M Ehemann, Jr