JPH0757648A - Aperture grill for cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide an aperture grill by which halation is not caused in an image in both end parts of an image screen even if it is installed and used in a cathode-ray tube of not less than a 16-inch type and of highly fine density. CONSTITUTION:In an aperture grill for a cathode-ray tube having an image screen of not less than 16 inches and of highly fine density, a thickness of an iron belt part in a slit forming part of the aperture grill is set not more than 15mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture grill for a cathode ray tube having a screen of 16 inches or more.

[0002]

2. Description of the Related Art Conventionally, an aperture grill has a slit layer formed by forming a resist layer on a steel plate, patterning a stripe-shaped slit shape, and then etching the exposed portion of the steel plate with a ferric chloride solution. Is formed and then a so-called etching method of removing the resist is performed. However, in recent years, in the aperture grille that is installed in the color picture tube for the display that requires a high-density and high-precision screen,
In order to meet the above requirements, it has become necessary to form the pitch of slits, which are electron beam passage portions, extremely finely.

However, when an attempt is made to form such an aperture grill with a fine pitch by using a conventional steel sheet by an etching method, many dimensional accuracy defects are produced in the slits, which inevitably reduces the product yield. . Further, when such an etching method is used, there is also a problem that it takes time to process the etching waste liquid.

[0004]

However, a normal aperture grill has a thickness of 30 to 50 μm, and the iron strip portion in the slit portion has a rectangular cross-sectional shape, which is 16 inches or more and has a high fine density. When the aperture grill is attached to the cathode ray tube and an image is captured, there is a problem that halation occurs at the end of the image.

It is an object of the present invention to provide an aperture grill which does not cause halation on an image at both ends of a screen even when used in a 16-inch or larger CRT having a high fine density. .

[0006]

As a result of various studies, the present inventor formed a resist layer on the surface of a conductor substrate, patterned the resist layer, and applied iron plating to the exposed portion of the conductor substrate caused by the treatment. After that, the conductor substrate is distorted by applying external stress or the like to peel off the end portion of the iron plating film, and the whole plating film is peeled off from this portion.
The inventors have found that the so-called "plating method" can be used to reduce the thickness in the slit forming portion and prevent halation, and have completed the present invention. That is, the present invention is an aperture grill for a cathode ray tube having a screen of 16 inches or more and a high fine density, in which the thickness of the iron strip portion in the slit forming portion of the aperture grill is 15 μm or less.

[0007]

In order to obtain a clear image on the screen of a cathode ray tube in a color television, it is necessary to correctly irradiate each of the fluorescent screens with red, green and blue electron beams. Then, the aperture grill has a role of filtering the electron beam so that the electron beam irradiates the fluorescent surface accurately at this time.

However, as described above, the shape of the iron strip portion forming the slit portion in the ordinary aperture grill is generally rectangular, and the thickness thereof is at least 30 to 50 μm.

On the other hand, in the case where the electron beam is irradiated near the center of the aperture grill on the picture screen of a television cathode ray tube, that is, when the incident angle with respect to the aperture grill is small, there is no problem. The angle of incidence of the electron beam on the aperture grill increases, and this tendency increases as the size of the television screen increases. For this reason, the electron beam emitted to the end of the aperture grille is reflected by the side wall surface of the rectangular iron strip formed in the slit as the thickness of the aperture grille increases, so that the conventional thick aperture grille can be used. On the screen used, halation tends to occur in the image, and this tendency becomes remarkable especially when the size of the cathode ray tube of the television becomes 16 inches or more.

According to a study made by the present inventor, an aperture for use as a cathode ray tube of a high-density television with a size of 16 inches or more and which does not cause halation due to reflection of an electron beam. The limit thickness of the grill was 15 μm, and it was found that this problem would hardly occur if the grill was formed with a thickness less than this.

Furthermore, the present inventor has further made a method for precisely controlling the thickness of the aperture grill to a thin film, that is, forming an electric iron plating film on the aperture grill according to a slit pattern provided on a conductor substrate. By adopting the method of peeling off, the present invention succeeded in easily obtaining the aperture grill of the present invention having a wall thickness of 15 μm or less.

As described above, when the aperture grill according to the present invention is used, even a 16-inch high-density television can receive an image without causing halation on the screen and can be manufactured. There are many advantages such as being extremely easy.

[0013]

EXAMPLES Examples of the present invention will be given below.

The conductor board has a length of 300 mm and a width of 400 mm,
A stainless steel plate having a thickness of 0.3 mm is used, a photoresist is applied on the surface of the stainless steel plate to a thickness of 20 μm, and a width of 200 μm, a length of 245 mm, and an interval of 50 are applied on the photoresist.
A patterning treatment was performed by covering with a photomechanical mask having 1300 μm slits, and exposing and developing. The conductor surface exposed by this operation was electroplated with iron under the conditions shown in Table 1 to form an iron plating film having a thickness of 15 μm.

[0015]

TABLE 1 Composition of the plating solution and the plating conditions (plating solution _{composition) FeCl 2 · 4H 2 O:} 2.01 mol CaCl _2: 1.62 molar Saccharin: 9.13 mmol of _{CH 3 (CH 2) 6 CH} 2 OSO 3 Na: 0.30 mmol (plating conditions) Temperature: 90 ° C. Anode current density: 5 A / dm ² positive electrode: Pt Electrolysis time: 18 minutes External stress is applied to one end of the substrate on which the iron plating film is formed by the above operation. Then, the iron plating film was peeled off from the distorted portion to obtain an aperture grill having a desired slit.

When the aperture grill obtained by the above method was mounted on a 16-inch TV in a high-density CRT and an image was displayed, halation did not occur at the edge of the screen.

Next, for comparison, in the above embodiment, the thickness of the photoresist formed was 25 μm, and the plating time in Table 1 was 24 minutes to form an electric iron plating film.
Other than that, an aperture grill having a thickness of 25 μm similar to that of the conventional method was prepared through the same procedure as in the above-mentioned example, and a cathode ray tube image test was conducted in the same manner as in the above-mentioned example. In some parts, the image had halation.

[0018]

As described above, the aperture grill according to the present invention can be used for a picture tube of a large-sized television having a size of 16 or more and a high fine density and can be used without causing halation, and can be manufactured. It can be said that the invention is industrially useful because it is easy.

Claims (1)

[Claims] 1. An aperture grill for a cathode ray tube having a screen of 16 inches or more and a high fine density, wherein the thickness of the iron strip portion in the slit portion of the aperture grill is 15 μm or less.