Zenith Electronics Corporation

Zenith Radio Corporation

Howard G Lange

Robert J Adler

James R Fendley

Paul Strauss

Charles J Prazak

Johann Steiner

John M Jarosz

Francis M Ray

Yong S Park

Kazimierz Lapinski

Charles J Brazak, Iii

Ronald Schulman

Johan Steiner

An apertured member for use in a CRT screen manufacturing device, or lighthouse, is disclosed as being spaced from the light source and having a light-transmitting slot of approximately parabolic shape. The axis of the parabola which is perpendicular to the CRT screen being made. This apertured member is useful for correcting beam landing misregistration errors resulting from the use of a self-converging yoke with the CRT.

Optical aperture device for manufacturing color cathode ray tubes

A system for standardized printing of CRT screens is disclosed. A preferred embodiment utilizes a standardized photoexposure stencil made without the use of a shadow mask aperture pattern and projection printing. The stencil is then placed in proximity to the screening surface during exposure. Front panel and mask support topography preparation methods and apparatus are disclosed, as are means and methods for compensating for variations among panel assemblies utilized in standardized printing of the screens. The system thereby produces high resolution screens which may accept interchangeable shadow masks.

System of printing standardized cathode ray tube screens

Process and apparatus are disclosed for use in the manufacture of a color cathode ray tube having a shadow mask with a central pattern of apertures mounted in tension on a transparent flat front panel. The mask aperture pattern is registered with a cathodoluminescent screen pattern of corresponding geometry and position on an inner surface of the panel. The shadow masks and front panels are respectively interchangeable. In a preferred arrangement, signals are developed which are indicative of the positions of a mechanically stretched mask aperture pattern and an associated front panel screen pattern relative to a reference or to each other. Responsive to such signals, there is effected a relative positioning of the mask and screen until registration between the patterns is achieved.

Method and apparatus for making flat tension mask color cathode ray tubes

A method is disclosed for use in the manufacture of a color cathode ray tube having a foil tension mask with a central pattern of apertures. A transparent flat front panel has a cathodoluminescent screen pattern on its inner surface. A plurality of mask support means, located on opposed sides of the screen pattern, have respective mask-receiving surfaces for receiving a shadow mask in tension. Q-height error data is developed according to the invention, and the aperture pattern of the mask in expanded and positioned in response to the error data to compensate for errors in Q-height to bring the mask apertures into registry with the screen pattern. Apparatus for measuring Q-height is also disclosed.

Process and apparatus are disclosed for use in the manufacture of a color cathode ray tube having a shadow mask with a central pattern of apertures mounted in tension on a transparent flat front panel. The mask aperture pattern is registered with a catholdoluminescent screen pattern of corresponding geometry and position on an inner surface of the panel. The shadow masks and front panels are respectively interchangeable. Signals are developed which are indicative of the positions of a mechanically stretched mask aperture pattern and an associated front panel screen pattern relative to a reference or to each other. Responsive to such signals, there is effected a relative positioning of the mask and screen until registration between the patterns is achieved.

This disclosure describes method and apparatus useful in the manufacture of shadow mask color cathode ray tubes of the flat tension mask type, wherein the shadow masks and associated glass front panels are respectively interchangeable during mask-panel assembly.

Methods and apparatus for making flat tension mask color cathode ray

This invention is concerned with ultra precise apparatus for forming a complex profiled face on a diamond tool blank. The apparatus comprises an abrading device in the form of a grinding wheel and a spindle means which includes a journal for supporting the grinding wheel. This journal is rotatably supported upon an air bearing. A platform, supported for rotation about a vertical pivot axis, is also supported for displacement in a horizontal plane along an axis perpendicular to the pivot axis. An air bearing supports the platform for rotation about the pivot axis while another air bearing supports the platform for displacement in the horizontal plane perpendicular to that axis. A tool chuck is mounted upon the platform and serves to present the tool blank to the grinding wheel. A cam, mounted adjacent to the platform, is provided with a surface whose contour is related to the complex profiled face to be formed on the tool blank. A cam follower is supported by the platform for engagement with the contoured cam surface. A micrometer device, in response to displacement of the cam follower by the cam surface, selectively positions the platform along an axis intersecting the pivot axis. Finally, means are provided for rotating the platform about its pivotal axis and for simultaneously effecting a relative travel of the cam follower along the cam surface, while the tool blank is presented to the grinding wheel, thus causing the grinding wheel to generate a complex profiled face on the tool blank.

Ultra precise tool forming apparatus

A single-sheet (i.e. two-surface) rear projection screen for television applications is described, in which the front or viewer-facing surface is formed with vertically running lenticules for horizontal image light distribution and the rear or projector-facing surface is formed with horizontally running lenticules for vertical image light distribution. There is no need for a diffuser. The lenticule profiles on both surfaces vary as a function of distance from the projection axis in a manner calculated to accomplish several optical objectives: collimation, cosine power fall-off compensation, and rearward reflection gradient compensation. Computer programs for calculating the profiles are disclosed.

Rear projection screen

In order to reduce changes in color balance which occur as a function of viewing angle, a 3-color projection TV system having one axial and two off-axis image projectors employs a lenticular image screen having a plurality of vertical lenticules for horizontal light distribution, all of which have the same unique optical profile. This profile is derived by starting with a location-dependent shape appropriate for a location directly in line with an off-axis image projector, in order to obtain an asymmetric profile. The minor portion of the asymmetric profile is then discarded, and replaced by a mirror image of the major portion, thus producing a lenticule profile which is symmetrical but of too coarse a pitch. That oversized profile is then scaled down to the proper pitch, and duplicated all across the breadth of the screen. The resulting screen rotates the peak exit angle of the off-axis colors into a normal angle with the screen, producing a marked reduction in color imbalance as seen from off-axis viewing locations.

Image projection screen with decreased color shift as a function of

An apparatus for use in producing an illumination pattern on an electrically conductive mask blank having a photoresist coating thereon for a color cathode ray tube. The apparatus comprises a rigid, transparent substrate which has a first preselected pattern on the substrate, having a preselected optical density. The first pattern has first areas corresponding in distribution to the pattern of apertures to be formed in a mask blank, at least a predetermined group of the first areas being smaller in size than the desired ultimate mask aperture size. The substrate has a second preselected pattern having second areas surrounding the first areas, at least a predetermined group of the second areas corresponding to the first group of areas and having the size and outer configuration of the desired ultimate mask apertures. A third area between the second areas of the second preselected pattern has an optical density substantially different from the optical density of the first areas of the first preselected pattern. The second areas have an optical density intermediate to the optical density of the first areas and the third areas. The first and second patterns are such as to effectively establish, upon exposure of the photoresist coating through the apparatus, a first image corresponding to the first pattern and a second image corresponding to the second pattern, the first and second images being capable of being separately developed in separate photoresist development operations.

Apparatus for making a color selection mask for a color cathode ray tube

This disclosure depicts a novel low cost, high performance color cathode ray tube of the shadow mask type, and methods and apparatus for manufacturing the tube. The tube has a novel envelope on a faceplate portion of which is corner-suspended a lightweight, non-self-rigid shadow mask. The tube has a variety of features and is especially adapted to be made by manufacturing methods which permit the screened faceplates to be interchanged, each with all others, and the shadow masks to be interchanged, each with all others, with consequent economies in manufacture and enhanced tube performance. This disclosure stresses methods of making masters employed in the screening of the tube faceplates and in mask manufacture.

Method for manufacturing a color cathode ray tube and for making

This disclosure depicts a method of forming a pattern of electron-transmissive apertures in a color selection mask for use in a color television cathode ray tube. The method comprises: providing an electrically conductive blank with a substrate layer and an aperture-defining layer; applying a coating of photoresist material on the aperture-defining layer; exposing the photoresist coating in a first preselected illumination pattern with a preselected degree of exposure and in a second preselected illumination pattern with a preselected degree of exposure substantially different from the preselected degree of exposure of the first preselected illumination pattern; developing the exposed photoresist coating corresponding to the first preselected illumination pattern; etching through the blank; developing the exposed areas of the photoresist coating corresponding to the second preselected illumination pattern thereby baring a portion of the aperture-defining layer; and etching the newly bared portion of the aperture-defining layer. Apparatus for use with the above-described method is disclosed.

Growing community of inventors

Prospect Heights, IL, United States of America

Howard G Lange