JPH06305756A - Production of glass panel - Google Patents

Abstract

PURPOSE:To prevent the conspicuousness of the nodal lines of a glass panel stuck to a cathode ray tube by a moire phenomenon. CONSTITUTION:The glass panel 6 is stuck to the outer flank of a screen 8 of the cat;hode ray tube 8 and a shadow mask 9 is disposed within the cathode ray tube 7. Slits 9a for striking the electron beam from an electron gun against phosphors 8a formed on the inner flank of the screen 8 are formed on this shadow mask 9. The nodal lines 6a, reams, etc., if any, on the glass panel 6, do not overlap in parallel on the phosphors 8a and the slits 9a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass panel attached to the surface of a cathode ray tube using a shadow mask.

[0002]

2. Description of the Related Art In a cathode ray tube, a beam from an electron gun is applied to a phosphor inside the screen of the cathode ray tube through a hole of a shadow mask so that a predetermined color is emitted. There are slit-shaped (trinitron) or dot-shaped holes in the shadow mask.

On the other hand, an explosion-proof glass panel is attached to the outside of the screen of the cathode ray tube. A method of manufacturing this glass panel will be described with reference to FIGS. FIG. 5 shows a blank material 100 obtained by cutting a float glass into a predetermined size, and a portion 101 to be a glass panel from the blank material 100.
A plurality of pieces are cut out and bent to form a glass panel 102 as shown in FIG. 6, and the glass panel 102 is attached to the outside of the screen of the cathode ray tube 103.

[0004]

By the way, the float glass can be obtained by casting glass melted in a melting furnace onto a horizontal tin bath and forming it into a ribbon shape. When a part of the furnace material is dropped into the glass base material and melted during the production of the float glass, this becomes the knuckles 104 in the flow direction of the float glass. Reams also occur as a drawback similar to the ganglion 104. The knotting streak 104 and the ream are different from the other parts only in refractive index, and therefore cannot be visually identified.

On the other hand, when a plurality of portions 101 to be glass panels are cut out from the blank material 100, the flow direction of the float glass and the short side direction of the glass panel are set to increase the yield as shown in FIGS. 5 and 6. Trying to match. Then, when the glass panel 102 thus obtained is attached to the outside of the screen of the cathode ray tube 103 provided with a slit-shaped or dot-shaped shadow mask, the knuckles 104 overlap the slits or dot-shaped phosphors of the cathode ray tube 103, The ganglion muscle 104 that has been invisible until now due to the moire phenomenon becomes apparent.

[0006]

In order to solve the above problems, the present invention is obtained by cutting a float glass into a predetermined size from a glass panel attached to a cathode ray tube using a slit type or dot type shadow mask. When cutting a plurality of blank materials, the slit hole direction or dot hole arrangement direction of the shadow mask and the flow direction at the time of manufacturing the float glass in the state of being adhered to the cathode ray tube were made non-parallel.

[0007]

Even if the glass panel has nodal lines, it does not overlap the slits or dot rows of the cathode ray tube shadow mask, so that the moire phenomenon does not occur.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, in the method of the present invention, float glass is manufactured by the float glass manufacturing apparatus shown in FIG.

In the float glass manufacturing apparatus, a melting furnace 1 for melting glass raw materials is arranged on the upstream side (the left side in the figure), and a tin bath 2 is arranged on the downstream side of the melting furnace 1 so as to be continuous from the melting furnace 1. The glass base material 3 is poured onto the tin bath 2 and formed into a ribbon-shaped float glass 4 while flowing over the tin bath 2. The float glass 4 is cut into a predetermined size to obtain a blank material 5.

Next, as shown in FIG. 2, a plurality of glass panels 6 ... Is cut out from the blank material 5. When the glass panel 6 is cut out, the positioning is such that the slit direction of the shadow mask when the glass panel 6 is attached to a cathode ray tube and the flow direction during float glass production are non-parallel, for example, orthogonal to each other.

When a part of the furnace material falls into the glass base material 3 and melts when the float glass 4 is manufactured, it is transparent to a part of the glass panel 6 but has a refractive index different from that of the other parts. 6a is formed, but since the knuckles 6a coincide with the flow direction at the time of manufacturing the float glass, the knuckles 6a and the slit direction of the shadow mask are not parallel (generally orthogonal).

FIG. 3 is a perspective view of a CRT having the glass panel 6 attached thereto, and FIG. 4 is an exploded perspective view showing an enlarged main part of the CRT, and the glass panel 6 is provided on the outer surface of the screen 8 of the CRT 7. Is attached, and a shadow mask 9 is arranged inside the cathode ray tube 7. The shadow mask 9 is provided with a slit 9a for applying an electron beam from an electron gun to a phosphor 8a formed on the inner surface of the screen 8. Has been done.

Since the glass panel 6 is cut out from the blank 5 with the above-described directionality, even if the glass panel 6 has the knots 6a, the reams, etc., the phosphor 8a and the slits are formed. 9a does not overlap in parallel.

In the embodiments, the shadow mask has a slit shape (trinitron system; including slot shape) in which a moire phenomenon is prominent, but a dot shape (dot shape) is also shown. The present invention can be applied.
Further, in the example, two glass panels are taken so that the longitudinal direction of the glass panel is parallel to the flow direction of the float glass, but the width of the float glass may be adjusted in order to increase the yield.

[0015]

As described above, according to the present invention,
When cutting out multiple glass panels to be attached to a cathode ray tube using a slit type or dot type shadow mask from a blank material obtained by cutting float glass to a predetermined size, the shadow mask attached to the cathode ray tube Since the slit direction or the dot array direction and the flow direction during float glass manufacturing were made non-parallel (substantially orthogonal), even if a glass panel with knuckles is attached to a CRT. Also, since the slits or dot rows of the cathode ray tube shadow mask do not overlap the knotting lines, the moire phenomenon does not occur and it is possible to prevent the deterioration of the commercial value.

[Brief description of drawings]

FIG. 1 is a plan view of a float glass manufacturing apparatus.

FIG. 2 is a plan view illustrating cutting out of a glass panel from a blank material.

FIG. 3 is a perspective view of a CRT equipped with a glass panel obtained by the method according to the present invention.

FIG. 4 is an exploded perspective view showing an enlarged main part of the CRT.

FIG. 5 is a plan view illustrating cutting of a glass panel from a conventional blank material.

FIG. 6 is a perspective view of a glass panel obtained by a conventional method.

FIG. 7 is a perspective view of a cathode ray tube to which a glass panel obtained by a conventional method is attached.

[Explanation of symbols]

4 ... Float glass, 6 ... Glass panel, 6a ... Node bar,
7 ... CRT, 8 ... Screen, 8a ... Phosphor, 9 ... Shadow mask, 9a ... Slit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01J 31/20 A 8326-5E

Claims (1)

[Claims] 1. A method of manufacturing a glass panel to be attached to a cathode ray tube using a slit type or dot type shadow mask, wherein a plurality of glass panels are cut out from a blank material obtained by cutting a float glass to a predetermined size. At the time of this cutting, the slit hole direction or dot hole arrangement direction of the shadow mask in the state of being adhered to the cathode ray tube and the flow direction at the time of manufacturing the float glass are made non-parallel to each other. Production method.