Abstract:
An annulus (12) attached adjacent the edge planes (33) of a CRT front panel (13) provides screen area savings, and in the preferred embodiment, panel protection, strengthening, and anti-implosion properties. The annulus (12) is preferably composed of a plurality of sections (18a, 18b, 18c, 18d) and incorporates a shadow mask support (17). The annulus (12) is attached to the front panel (13) before receiving the shadow mask (23) and becomes a part of the CRT envelope. In a preferred embodiment, the annulus (12) is composed of ceramic and is x-ray shielded by an application of lead-based frit (41).
Abstract:
An improved front assembly for a color cathode ray tube having a tension foil shadow mask. The faceplate of the tube has on its inner surface a centrally disposed phosphor screen surrounded by a peripheral sealing area adapted to mate with a funnel. A shadow mask support structure (34) is provided for supporting a shadow mask in tension on the structure and spacing the shadow mask from the screen. The support structure includes an undulated member (60) surrounding the phosphor screen which member can take a number of forms including a strip defining a bottom sinuous edge (64) for securing the support structure to the faceplate and a top sinuous edge (62) for securing the shadow mask to the support structure. A cap (68) may be provided for securement to the top sinuous edge of the undulated strip to provide a land for securing the shadow mask to the support structure. Alternatively, the undulated member can be formed with peaks (66a) and valleys (66b) which are flattened in a common plane and provide means for securing the support structure to the faceplate. The peaks are flattened in a common plane and provide means for securing the shadow mask to the support structure. In a further modification, the support member includes an upper, flattened ridge for securing the shadow mask to the support structure. A plurality of legs depend from the ridge and at least a series of the legs is flared outwardly from one side of the ridge to facilitate securing the support structure to the faceplate and to stabilize the support structure under the tension of the shadow mask. Preferably, the mask support structure physically penetrates the faceplate for permanent, cementless anchoring of the structure to the faceplate. The embedment of the mask support structure is of such depth as to cause the structure to resist tensile forces created by the mask. Also disclosed is a process for securing a support structure for a tensed foil shadow mask to a glass faceplate.
Abstract:
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. 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.
Abstract:
A process is disclosed for use in the manufacture of a color cathode ray tube having a rectangular flat faceplate. The process comprises positioning the faceplate in a predetermined x-y plane by referencing faceplate a-b-c reference areas on two adjacent edges or sides of the faceplate with complementary a-b-c reference points on a faceplate locating fixture; the fixture also has three spaced six-point precision indexing means. With the faceplate a-b-c reference areas and the faceplate locating fixture a-b-c points mutually referenced, six-point precision indexing means are attached to the faceplate in registration with the precision indexing means on the faceplate locating fixture. Using the precision indexing means attached to the faceplate, a shadow mask is registered with the faceplate through the use of complementary precision indexing means to provide a faceplate shadow mask assembly in mutual precise registry. Using the registered faceplate-shadow mask assembly, a pattern of phosphors is photodeposited on the faceplate by photoexposure means. The registry of the pattern of phosphors and the shadow mask is accomplished according to the invention with a precision made possible by the use of the six-point precision indexing means, and the location of the patterns on the faceplate is made possible by the use of the a-b-c referencing of the faceplate and the faceplate locating fixture.