MXPA97003014A - Cromocinesco front plate panel - Google Patents

Abstract

The present invention relates to an improved chromocinescope (10) including a glass envelope (11) comprising a front plate panel (12), a funnel (15) and a neck (14). The front panel panel has four sides (L, S) and four corners and includes a transparent rectangular front plate (18), which has a cathodic luminescence screen (22) on an internal surface thereof and a side wall (20) which extends peripherally from the front plate. The end of the side wall facing the funnel has a junction surface (21) that is sealed to the funnel. The improvement comprises the sidewall joining surface (21, 31) having a variable width around the periphery of the panel, wherein the wider portions of the sidewall joining surface (21) are located along the length of the wall. the sides of the panel and the narrower portions of the side wall joining surface (31) are located at the corners of the panel. The width of the side wall joining surface is from 5% to 17% less than the corners of the panel than in the centers of the bread sides

Description

CROMOCIIMESCOPE FRONT PLATE PANEL This invention relates to chromocopinescopes and, particularly, to variations in the designs of faceplate panels to accommodate extended panels and to reduce the weight of the panels, while retaining sufficient panel strength to withstand atmospheric pressures. A cromocinescope has a glass envelope comprising a neck, a funnel and a rectangular face plate panel. The faceplate panel includes a front faceplate that is surrounded by a peripheral side wall. The side wall of the faceplate panel is sealed to a large end of the funnel by a glass frit. The surfaces of the opposite ends of the side wall of the panel and the funnel are referred to as joining surfaces. Between the side wall of the panel and the faceplate of the panel, there is a transition zone that includes a joint radius. Recently, an effort has been made to extend or enlarge the size of an electronic tube screen by reducing the joint radius, at least at the corners of a tube, while not increasing the overall size and external dimensions of the tube. . One of the problems that occurs when changing the joint radius of a panel is that the inner surface of the side wall of the panel becomes less inclined relative to the joint surface of the side wall (i.e., O in the FIG. 3 becomes smaller This shallow inclination creates a problem in the removal of the panel forming plunger from the panel during the formation of the same in the glass factory This problem can not be solved by thinning the side wall of the panel complete, as the thickness of the sidewall of the panel affects the strength of the panel, and the resistance of the panel must be maintained so that the kinescope supports the atmospheric load on it and to meet the safety criteria. of a new panel design that will maintain the strength and a large inclination (O) necessary for easy removal from a mold during fabrication. It provides an enhancement in a chromo-kinescope of a type that includes a glass envelope comprising a faceplate panel, a funnel and a neck. The front panel panel has four sides and four corners and includes a transparent rectangular front plate, having a screen with cathodic luminescence on an internal surface thereof and, a side wall extending peripherally from the front plate. The end of the side wall facing the funnel has a joint surface that has a variable width around the periphery of the panel, where the wider portions of the joint surface of the side wall are located along the sides of the panel and the narrower portions of the joining surface of the side wall are located at the corners of the panel. The width of the joining surface of the side wall is 5% up to 17% less at the corners of the panel than at the centers on the sides of the panel. In the drawings: FIGURE 1 is a side view, partially in axial section, of a chromocinescope. FIGURE 2 is a plan view of the back of the faceplate taken on lines 2-2 of FIGURE 1. FIGURES 3, 4 and 5 are cross-sectional views of the side walls of the faceplate panels and the funnel portions, which illustrate the prior art, the development problems and the present invention. FIGURES 6 and 7 are cross-sectional views of the junctions between the side walls of the faceplate panel and the funnels. FIGURES 1 and 2 show a rectangular chromocinescope having a glass bulb or envelope 11 comprising a rectangular faceplate panel 12 and a tubular neck 14 connected by a rectangular funnel 15. The funnel 15 has an internal conductive coating (not shown) extending from a button of anode 16 towards the neck 14. The panel 12 comprises a transparent rectangular viewing front plate 18 and a peripheral flange or side wall 20 including a joining surface 21 which is sealed to the funnel 15 by a glass frit 17. A phosphorescent screen of three colors 22 is transported by the inner surface of the faceplate 18. The screen 22 is, preferably, a line screen with the phosphor lines connected in triads, each triad including a phosphor line of each of the three colors. Alternatively, the screen may be a dot screen and may or may not include a light absorption matrix. A multi-aperture color selection electrode or shadow mask 24 is removably mounted in a predetermined separate relationship to the screen 22. An electronic cannon 26, shown schematically by dotted lines in FIGURE 1, is centrally mounted within the neck 14 to generate and directing three electronic beams along converging paths through mask 24 and screen 22.

As shown in FIGURE 2, the rectangular faceplate panel 12 includes two centrally located orthogonal axes, a major axis X and a minor axis Y and two diagonals D extending from corner to corner. The two long sides L of the periphery of the faceplate panel 12 substantially parallel to the major axis X and the two short sides S substantially parallel to the minor axis Y. FIGURE 3 shows a cross section of the panel 12 at the end of a diagonal D The dotted line 28 indicates a revised form of the inner surface of the panel, where the screen area is enlarged by reducing the radius of curvature or bonding radius between the faceplate 18 and the side wall 20, as long as maintains the width of the side wall or the joining surface of the panel 21. The requirements for a larger screen include a change in the contour of the inner surface and a change in the inclination of the inner surface of the side wall by an angle O In a kinescope where the radius of union, designated RO and Rn, respectively, is changed from 12 7 mm to 2 54 mm, the angle O is approximately 1 ° The angle of inclination changes cr a problem during the manufacture of the panel, since the stepped inclination causes difficulties in the removal of a forming plunger (not shown) from the panel during the manufacture thereof In FIGURE 4 it is shown by the dotted line 30 and in the FIGURE 5 through continuous line 32 a modality that solves the glass manufacturing problem In this solution, the bond radius is changed the same as it was in FIGURE 3, although the side wall of panel 31 is narrower, maintain the same angle of inclination of the inner surface of the side wall. However, another problem, related to resistance, is caused by a narrower panel joining surface around the entire perimeter of the panel. This last problem is illustrated by the comparison of FIGURE 6 and FIGURE 7. FIGURE 6 shows a panel mode where the joining surface 21 of the panels substantially the same width as the attachment surface of the funnel In this case, the frit material forms complete fillets 33 and 35 on the inside and outside of the kinescope However, in the embodiment of panel shown in FIGURE 7, where the width of the bonding surface 31 of the panel is substantially less than the width of the attachment surface of the funnel, the frit material forms a complete fillet 37 on the outside of the kinescope, although a partially distorted fillet 39 on the inside of the kinescope. When this condition occurs along the side of the panel, it results in a greatly weakened union between the panel and the funnel. Typically, in the prior art kinescopes, the width of the bonding surface on the panel is relatively uniform around the perimeter of the panel, varying less than 5%. However, it has been found that, when the glass cover is dislodged, the mechanical stresses in the front panel panel, caused by the vacuum load, are greater at the ends of the major and minor axes, in the centers of the four sides and smaller at the corners of the panel, at the ends of the diagonals. In addition, it has been found that an appropriate amount of mechanical strength can be maintained within a kinescope that has a reduction in the width of the bonding surface, at the corners of the panel only, from 5% to 17%. Therefore, in the novel kinescope of the present invention, the bonding surface of the panel is wider along the L and S sides of the panel, as shown in FIGURE 6, and narrower at the corners of the panel , as shown in FIGURE 7.

Claims (1)

1. A chromocinescope including a glass envelope comprising a faceplate panel, a funnel and a neck, the faceplate panel having four sides and four corners and including a transparent rectangular faceplate and a peripheral side wall, the side wall having a joining surface that is sealed to the funnel, characterized by the sidewall joining surface (21, 31) having a variable width around the periphery of the panel (12), wherein the wider portions of the surface side wall junction (21) are located along the sides of the panel (L, S) and the narrower portions of the sidewall joining surface (31) are located in the corners of the panel, and in where the width of the joining surface of the side wall of the panel is from 5% to 17% lower in the corners of the panel than in the centers of the sides of the panel.