JPH06187924A - Light emitting element - Google Patents

Abstract

PURPOSE:To improve the dimensional accuracy, mechanical strength and image display grade respectively of a light emitting element so as to provide the element with highness in quality and operational reliability by forming a beveled portion of specific curvature in each of edges of a front panel forming a vacuum envelope and forming a fine projected face in the surface of display-face side of the panel. CONSTITUTION:A fine irregular pattern 16 of an extent from 0.1 to 0.5mm in the radius of curvature is formed in the surface of display-face side of a front panel 2A forming a vacuum envelope 1, and a beveled portion 17 of about 0.5mm in the radius of curvature is formed in each of the edges of the panel 2A. The pattern 16 and the beveled portions 17 are formed each through the metallic molding process of putting a plate glass member in a metallic mold made of carbon or the like and then heat-treating the glass member at a temperature of about 700 deg.C to about 950 deg.C for an extent from one to two hours. This plate glass member is prepared by cutting soda glass, potash glass or the like to measure, and simultaneously with this preparation, also the surface of cut face 2a of the glass member is formed in flatness. This process can improve the dimensional accuracy, mechanical strength and image display grade respectively of a light emitting element so that the element may be provided with highness in quality and operational reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting element which constitutes a pixel of a large screen color display device.

[0002]

2. Description of the Related Art FIG. 3 shows a basic structure of a display tube for a light source as a conventional light emitting element of this type.
4A is a plan view, FIG. 4B is a cross-sectional view taken along line AA ′ of FIG.
FIG. 3 is an exploded perspective view of the multi-cell in which a phosphor screen having R (red), G (green) and B (blue) phosphors as one pixel is arranged in a matrix of 3 × 3 pixels with the number of pixels being the number of pixels. The type of light source display tube will be described. In these figures, reference numeral 1 denotes a vacuum envelope as a glass tube which is hermetically sealed by a front panel 2, a rear panel 3 and a tubular side plate 4, and an inner surface of the front panel 2 has a three-color phosphor R. , G, B are applied as a unit pixel in a matrix to form a fluorescent display portion 5 composed of 3 × 3 pixel fluorescent screens 5R, 5G, 5B. Phosphor screen 5 here
The subscripts of R, 5G, and 5B correspond to red (R), green (G), and blue (B), respectively. Reference numeral 6 denotes an anode electrode group composed of a plurality of accelerating anodes 6 ₁ , 6 ₂ ... Arranged correspondingly around the respective fluorescent screens 5R, 5G, 5B of the fluorescent display section 5 and for accelerating these. A high voltage is applied to the anodes 6 ₁ , 6 _2, ... Via the external terminal 13. Reference numeral 7 denotes a cathode electrode group in which electron emission cathodes 7 _{11 to} 7 ₃₃ (not shown) are independently arranged in correspondence with the respective fluorescent screens 5R, 5G and 5B of the fluorescent display section 5. Both ends of each of the cathodes 7 _{11 to} 7 ₃₃ are supported between a pair of supports fixed on the rear panel 3. In the cathodes 7 _{11 to} 7 ₃₃ , the first and second subscripts correspond to the first to third rows and the first to third columns, respectively. In addition,
Each cathode 7 _{11-7 33,} for example, a straight thermal coated with oxide oxide coated indirectly heated or tungsten on the Ni sleeve can be used.
Reference numeral 8 denotes a grid electrode group including row selection control grids 8 ₁ to 8 ₃ arranged between the cathode electrode group 7 and the fluorescent display portion 5, and these control grids 8 ₁ to 8 ₃
Numeral 8 ₃ is an electron passage hole for passing the electron beam 11 from the cathodes 7 _{11 to} 7 ₃₃ as a non-focused beam in the row direction corresponding to each of the fluorescent screens 5R, 5G and 5B of the fluorescent display unit 5. 9 _{1 to} 9 ₃ are provided. Reference numeral 10 indicates the rear surface side of the cathode electrode group 7, that is, on the rear panel 3 forming a part of the vacuum envelope 1, the respective fluorescent screens 5R and 5R of the fluorescent display unit 5.
G, a back electrode group comprising a back electrode 101 to 103 for respectively oppositely disposed striped column selection to the column direction in response to 5B, these back electrode 10 ₁ to 1
0 ₃ is formed of a conductor layer such as Ag. And each back electrode 10 ₁ to 10 described above ₃ each cathode 7 _11-7
By applying a positive potential of the negative and 0V or several V with respect to ₃₃ of the potential, which is intended to control the electron beam 11 to be emitted from their cathode 7 _{11-7 33.} Reference numeral 12 is a lead pin as an external terminal for pulling out the respective electrodes such as the cathode electrode group 7, the grid electrode group 8 and the back electrode group 10 from the back panel 3 to the outside. The lead pin 12 is embedded in the back panel 3. It penetrates and is pulled out. Reference numeral 14 is a frit glass that joins the tubular side plate 4 to the front panel 2 and the rear panel 3 to form the vacuum envelope 1.

[0003]

However, in the conventional light source display tube, the front panel 2 and the rear panel 3 constituting the vacuum envelope 1 are obtained by cutting a large glass plate material into a predetermined size by cutting. Since they were used, a lot of strain is latent in those ridges, and when stress is applied to these portions, minute cracks and cracks are likely to occur, and as a result, the mechanical properties of the vacuum envelope 1 are increased. There are problems such as a decrease in strength, a decrease in manufacturing yield, and an increase in defective rate after commercialization. As a solution to such a problem, as shown in the enlarged cross-sectional view of the main part in FIG. 5, the chamfered portion 15 in which the cutting surface 2a is a flat surface is provided on the ridge portion of the front panel 2 to form the ridge portion. There has been proposed a light-emitting device that has improved mechanical strength by eliminating the occurrence of minute chips and cracks that occur in (Japanese Patent Application No. 3-1
08292). However, as described above, when the front panel 2 having the cutting surface 2a as the flat surface is used,
There was a problem described below. The cutting surface 2a of the front panel 2 is the display surface 2b.
It is difficult to be perpendicular to the above, and the accuracy of the outer dimension of the front panel 2 is reduced. That is, when cutting flat glass with a glass cutter, the surface is scratched with diamond or the like, but the direction of the scratch is slightly different from the vertical surface, and the cut surface is difficult to be perpendicular to the surface. The corner portion 2c of the cutting surface 2a becomes an acute angle, chipping is likely to occur, and the surface strength decreases. Further chamfering is required to prevent the corners 2c of the cutting surface 2a from being chipped. It is difficult to distinguish the display surface 2b side of the front panel 2 from the phosphor screen forming surface 2d side. Since the display surface 2b side of the front panel 2 is a flat glass surface, the light reflectance with respect to external light is high, and the display quality (visibility) is reduced.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to enable a chamfered portion of a front panel to be obtained with high precision and high mechanical strength. It is to provide a light emitting element. Another object of the present invention is to display the side of the front panel,
An object of the present invention is to provide a light emitting element that can be easily distinguished from the side on which a fluorescent screen is formed and that can improve display quality.

[0005]

In order to achieve such an object, a light emitting device according to the present invention is provided with a chamfered portion having a curvature at a ridge portion of a front panel constituting a vacuum envelope and the front surface thereof. A fine projection surface is provided on the display surface side of the panel.

[0006]

In the light emitting device according to the present invention, since the fine projection surface is provided on the display surface side of the front panel,
The external light will be diffusely reflected. Also, by providing a chamfered portion with curvature on the ridge of the front panel,
Changes in the external dimensions of the front panel are reduced.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part showing a configuration according to an embodiment of a light emitting device according to the present invention. The same parts as those in the above-mentioned drawings are designated by the same reference numerals and the description thereof will be omitted. In the figure,
On the surface of the front panel 2A constituting the vacuum envelope 1 on the side of the display surface 2b, as shown in the enlarged cross-sectional view of FIG. 2, for example, a fine uneven pattern 16 having a radius of curvature of about 0.1 to 0.5 mm. Are formed. Further, a chamfered portion 17 having a curvature radius of about 0.5 mm is formed on each ridge of the front panel 2A. These fine concavo-convex pattern 16 and chamfered portion 17 have a predetermined size in a mold made of, for example, carbon and the like on the inner surface of which the concavo-convex surface corresponding to the fine concavo-convex pattern 16 and the chamfered portion 16 is formed. By inserting a plate glass material such as soda glass, potash glass, lead glass, borosilicate glass, etc., which has been cut into, into the mold by heat treatment at about 700 to 950 ° C. for about 1 to 2 hours, Can be formed. In addition, the surface of the cutting surface 2a is also flattened at the same time by the molding of the mold that performs this heat treatment.

According to this structure, the front panel 2A
By forming the fine concavo-convex pattern 16 on the surface of the display surface 2b side, it becomes extremely easy to distinguish between the display surface 2b side of the front panel 2A and the phosphor screen forming surface 2d side, and the workability can be improved. At the same time, the light reflectance with respect to external light can be reduced, and the display quality (visibility) can be improved. Further, by forming the chamfered portion 17 having a curvature at each ridge of the front panel 2A, the cutting surface 2a of the front panel 2 becomes vertical to the display surface 2b thereof, and the outer dimensions of the front panel 2A are high. Can be secured with accuracy. In addition, the corners 2c of the cutting surface 2a are less likely to be chipped and the surface strength can be improved. Further, since the corner portion 2c of the cutting surface 2a becomes a curved surface, the chamfering process is unnecessary.

In the above-described embodiment, the chamfered portion 17 having a curvature at each ridge of the front panel 2A.
Although the case where the above is provided has been described, it goes without saying that the present invention can also be applied to the rear panel 3.

[0010]

As described above, according to the present invention,
The dimensional accuracy and mechanical properties of the front panel are improved by providing a chamfered portion with a curvature at the ridge of the front panel that constitutes the vacuum envelope and providing a fine protruding surface on the display surface side of the front panel. The strength can be significantly improved, diffused reflection due to external light on the display surface of the front panel is eliminated, and the display quality (visibility) can be significantly improved. Therefore, a light emitting element with high quality and reliability can be obtained. Has excellent effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a light emitting device according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of FIG.

3A is a plan view showing the basic structure of a conventional light source display tube, and FIG. 3B is a sectional view taken along the line AA ′.

FIG. 4 is an exploded perspective view of a part of FIG.

FIG. 5 is an enlarged sectional view of an essential part for explaining a problem of the conventional light source display tube.

[Explanation of symbols]

1 Vacuum Envelope 2a Cutting Surface 2b Display Surface 2c Corner 2d Fluorescent Surface Forming Surface 2A Front Panel 3 Rear Panel 4 Cylindrical Side Plate 5 Fluorescent Display 6 Anode Electrode Group 6 ₁ Acceleration Electrode 6 ₂ Acceleration Electrode 6 ₃ Acceleration Electrodes 7 Cathode electrode group 8 Grid electrode group 10 Backside electrode group 11 Electron beam 12 Lead pin 13 External terminal 14 Frit glass 15 Chamfering part 16 Concavo-convex pattern 17 Chamfering part

Front page continuation (72) Inventor Sashiro Uemura 700, Wada, Ueno-cho, Ise-shi, Mie Ise Denshi Kogyo Co., Ltd. (72) Shunichi Futashi, 6-14 Maruo-cho, Nagasaki, Nagasaki Prefecture Company Nagasaki Manufacturing (72) Inventor Zenichiro Hara 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi Electric Corporation Nagasaki Manufacturing (72) Inventor Mitsumasa Umezaki 8-1-1 Tsukaguchihonmachi, Amagasaki, Hyogo Prefecture Electric Device Co., Ltd. Material Device Research Center (72) Inventor Mitsuo Inomochi 8-1-1 Tsukaguchihonmachi, Amagasaki City, Hyogo Sanryo Electric Co., Ltd. Material Device Research Center

Claims (1)

[Claims] 1. A vacuum envelope in which a front panel is attached to a front surface of a tubular side plate and a back panel is attached to a rear surface of the tubular side plate in an airtight manner, and a fluorescent display portion formed by arranging fluorescent surfaces in a matrix on an inner surface of the front panel. An anode electrode group composed of a plurality of accelerating anodes arranged around the phosphor screen, a cathode electrode group in which electron emission cathodes are arranged independently corresponding to the phosphor screen, and the cathode electrode A plurality of electron passage holes, which are arranged between the group and the fluorescent display portion in a row or column direction corresponding to each fluorescent surface of the fluorescent display portion and through which electrons from each cathode pass as an unfocused beam. A grid electrode group consisting of control grids, and a back electrode consisting of a plurality of back electrodes arranged in the column or row direction on the back side of the cathode electrode group corresponding to each phosphor screen of the fluorescent display unit. An electrode group, wherein the intersection of each control grid of the grid electrode group and each back electrode of the back electrode group constitutes a matrix, wherein a ridge portion of a front panel constituting the vacuum envelope is provided. A light emitting device, characterized in that a chamfered portion having a predetermined curvature is provided on the front surface of the front panel and a fine projection surface is provided on the surface of the display surface of the front panel.