JPS5810358A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To reduce the stipping phenomenon on a resin layer greatly, and realize a clear picture surface which can be easily seen by decreasing the degree of the curvature on face part of a panel glass. CONSTITUTION:The outer surface of a face part 1a of a panel glass 1 is made to have a large radius of curvature so that the thickness difference between a peripheral part 4b and a central part 4a of a transparent resin layer 4 within an effective picture surface becomes below 2.5mm.. Accordingly, the radius of curvature of an outer surface 1b of the face part 1a is 2,500mm., and that of an inner surface 1c of the face part 1a is 560mm.. Here, the difference in thickness between the central part 4a of the layer 4 and the peripheral part 4b which is apart from the part 4a by a gap of 98mm. is 1.9mm.. Therefore, when a filter glass 3 is attached so that it is apart from the center of the face part 1a by a gap of 1.8mm., the thickness of the peripheral part 4b is around 3.7mm.. Consequently, any striping phenomenon caused due to the thickness of the layer 4 is almost prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube in which a flat glass plate, such as a filter glass, is attached to the outer surface of a panel glass.

A conventional cathode ray tube of this type will be explained with reference to FIG. In the figure, (1) is panel glass, (2)
H funnel glass, (3) TI'i panel glass (1
) is coated on the outer surface (1b) of the filter glass with a transparent resin layer (4) made of unsaturated polyester resin or the like interposed therebetween. In such a cathode ray tube, the degree of curvature of the inner surface (io) of the face portion (1a) of the panel glass (1) is generally about 550 to 570W in radius of curvature, and that of the outer surface (1b) is about 560-560W. It was about 600 tax. Therefore, there is a large difference in thickness between the central part (4a) and the peripheral part (4b) of the transparent resin layer (4) to which the filter glass (3) is attached, resulting in uneven curing during the curing process of the resin. There was a problem that striae phenomenon was likely to occur due to this. This striae phenomenon generally tends to occur when the thickness of the resin layer (4) exceeds 5 mm, and as a result of the refractive index of the generated portion being extremely different from the surrounding area by VC, the screen becomes distorted when a raster is displayed on the cathode ray tube. It's so hard to even look at it.

For example, in an 8-inch cathode ray tube in which the outer surface (1b) of the face portion (1B) of the panel glass (1) has a radius of curvature of 560 wJI, the center portion (4a) of the resin layer (4) and the periphery 98 mm away from this The difference in the thickness of the part (4b) is 8.6 square meters, and the flat filter glass (3) is placed in the central part (4b).
When the thickness of a) is 18 m, the thickness of the peripheral part (4b) becomes 10.4 m, causing a remarkable striae phenomenon.

This invention was made to improve the above-mentioned conventional drawbacks, and aims to provide a cathode ray tube in which the striae phenomenon is less likely to occur by reducing the degree of curvature of the face portion of the panel glass. .

In order to achieve the above object, the present invention provides that the outer surface of the face portion of the panel glass has a large radius of curvature such that the difference in thickness between the peripheral portion and the central portion of the transparent resin layer within the effective screen is λ5 or less. It is characterized by having the following. That is, if the difference in the thickness of the resin layer is less than a5+mw, the thickness of the center part of the resin layer is set to be sufficient to adhere and hold a flat glass plate such as a filter glass. Also, the thickness of the peripheral portion of the resin layer within the effective screen can be set to a thickness of 5 tones or less where no striae phenomenon occurs.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows the invention applied to the 8-type cathode ray tube. In the figure, the face portion (1a) of the glass panel (1) has an outer surface (1b) with a radius of curvature of 2500 m.
The m-inner surface (10) is in 560th tone. in this case,
The difference in thickness between the central part (4a) of the transparent resin layer (4) and the periphery 1 (4b) 98 m away from this is 19 mm, so the filter glass (3) is attached to the face of the panel glass (1). When the center collar L 8 m li of the part (1&) is applied, the thickness of the peripheral part (4'b)11') is 3.7
It is about m. Therefore, the striae phenomenon due to the thickness of the resin layer (4) hardly occurs, and even if it occurs very rarely, it is very slight and cannot be visually recognized, and there is no problem at all in practical use.

As described above, in the implicit wire tube of the present invention, since the curvature of the outer surface of the face of the panel glass is set to be very small, the above-mentioned resin layer, which was difficult to avoid in the past, As a result, the striae phenomenon can be eliminated or greatly reduced, and as a result, an easy-to-read and clear screen can be provided.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing a conventional cathode ray tube, and FIG. 2 is a partially cutaway side view showing a cathode ray tube according to an embodiment of the present invention. (1)...Glass panel, (1a)...Face portion, (ib)...Outer surface, (3)...Filter glass,
(4)...Transparent resin layer, (4a)...Central part, (4
b) ... peripheral area. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1 4 Figure 2

Claims (1)

[Claims] (1) In a cathode ray tube in which a flat glass plate is attached to the outer surface of the face of the panel glass through a transparent resin layer, the outer surface of the face of the panel glass is the same as the transparent resin layer within the effective screen. A cathode ray tube characterized in that it is formed with a curved surface such that the difference in thickness between the peripheral part and the central part is 2.5W or less.