JPH053005A - Light-emitting element - Google Patents

Abstract

PURPOSE:To provide a uniform color balance by making different the opening diameters of electron passage sections in a control grid in accordance with the light emitting efficiency of the fluorescent surface. CONSTITUTION:The electron passage section of a control grid 82A constituting a grid electrode group 8A is bored with a large number of meshes which are radially projected substantially with the same diameter toward the side of a fluorescent display section 5, whereby dome-shaped mesh sections 91A, 92A and 93A are integrally formed. As compared with the opening diameter of the mesh 93A corresponding to a fluorescent surface 5R, the opening diameter of the mesh 92A of a fluorescent surface 5B is large and the opening diameter of the mesh 91A of a fluorescent surface 5G is made small. With this construction, when substantially the same control voltages are applied to the control grids 81A, 82A, and 83A, the amount of the electron beam passing through the meshes 91A, 92A, and 93A can be controlled corresponding to the emitted light brightness of each fluorescent surface 5G, 5B, and 5R. This makes it possible to obtain a uniform color balance.

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. 2 shows a basic structure of a display tube for a light source as a conventional light emitting device of this type.
Is a plan view, FIG. 3 (b) is a cross-sectional view taken along the line AA ', and FIG.
FIG. 3 is an exploded perspective view thereof, 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 1 pixel. A cell type 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. The 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. Here, the phosphor screen 5R,
The subscripts of 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 corresponding to the periphery of each of the fluorescent screens 5R, 5G, 5B of the fluorescent display unit 5, and for accelerating these. A high voltage is applied to the anodes 6 ₁ , 6 _2, ... Through 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, 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. Here, the cathodes 7 _{11 to} 7 ₃₃ have the first and second subscripts corresponding 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
Corresponding to each of the fluorescent screens 5R, 5G, 5B of the fluorescent display unit 5, the electron passage holes 9 ₁ to pass the electron beams 11 from the cathodes 7 _{11 to} 7 ₃₃ as unfocused beams in the row direction. to 9 ₃ is provided. 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 phosphor screens 5R, 5G, 5B of the phosphor display section 5.
Is a back electrode group consisting of strip-shaped column-selecting back electrodes 10 ₁ to 10 ₃ which are arranged to face each other in the column direction, and these back electrodes 10 ₁ to 10 ₃ are conductor layers such as Ag. Are formed from. And the back electrode 10 ₁ to 10 ₃ as described above by applying a positive potential of the negative and 0V or several V relative to the potential of the cathode 7 _{11-7 33,} releasing from their cathode 7 _{11-7 33} The electron beam 11 is controlled. In addition, 12 is a lead pin as an external terminal for pulling out each electrode of the cathode electrode group 7, the grid electrode group 8 and the back electrode group 10 from the back panel 3, and 14 is the cylindrical side plate 4, the front panel 2 and the back panel 3. It is a frit seal that joins and.
In addition, the electron passage holes 9 _{1 to} 9 ₃ formed in the respective control grids 8 ₁ to 8 ₃ forming the grid electrode group 8 described above are shown in FIG.
With domed mesh portion 9 _1A to 9 _3A as shown in, the cathode 7 _{21-7 23} evenly spread in the phosphor screen 5G electrons emitted from, 5B, like the dome is possible uniformly irradiate the 5R The spread of the electron beam 11 can be arbitrarily adjusted according to the curvatures of the mesh portions 9 _{1A to} 9 _3A . Moreover divergence of the electron beam is increased the larger the curvature of the dome-shaped mesh portion 9 _1A to 9 _3A, the light source display tube tube length can be shortened in the display tube has been proposed (JP 62- No. 2412256).

[0003]

However, in the conventional display tube for a light source, the dome-shaped mesh portions 9 _1A , 9 which diffuse the electron beam 11 from the cathodes 7 _{21 to} 7 ₂₃ to the fluorescent screens 5G, 5B, 5R. because _2A, 9 _3A mesh opening diameter has been formed in a predetermined size, to obtain a color image of a desired hue, the phosphor screen 5G, 5B, controlled so as to correspond to the emission color of 5R grid 8 By changing the voltage applied to ₁ to 8 ₃ etc., each dome-shaped mesh part 9 _1A , 9 _2A ,
It is necessary to control the amount of the electron beam 11 passing through 9 _3A ,
There is a problem that the control circuit becomes complicated.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its object is to:
An object of the present invention is to provide a light emitting device capable of adjusting the amount of an electron beam passing therethrough according to the emission color of the phosphor screen.

[0005]

In order to achieve such an object, the light emitting device according to the present invention is such that the aperture diameter of the electron passage portion of the control grid is made different according to the luminous efficiency of each phosphor screen. is there.

[0006]

In the present invention, the amount of electron beams passing through the electron passage portion of the control grid is controlled.

[0007]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view of a main part of a display tube for a light source for explaining the structure of an embodiment of a light emitting device according to the present invention. FIG. 1A is a sectional view, and FIG. It is a principal part plan view of a grid electrode, and the same portions as those in the above-mentioned drawings are denoted by the same reference numerals and the description thereof will be omitted. In the figure, for example, the control grid 8 _2A that constitutes the grid electrode group 8A has a large number of meshes for passing electrons and has a diameter substantially equal to that of the fluorescent display 5 side. Domed mesh parts 9 _1A , 9 _2A protruding in a hemispherical shape,
9 _3A is integrally formed. And it is formed by increasing the opening diameter of the dome-shaped mesh portion 9 _2A corresponding to the fluorescent surface 5B with respect to the mesh opening size of the dome-shaped mesh portion 9 _3A corresponding to the phosphor screen 5R, domed corresponding to the phosphor screen 5G It is formed by reducing the opening diameter of the mesh portion 9 _1A .
That is, as shown in FIG. 6B, the luminous efficiency of the phosphor is higher in the order of the phosphor screen 5G, the phosphor screen 5R, and the phosphor screen 5B. Accordingly, the mesh opening diameter is correspondingly changed to the dome-shaped mesh portion 9 _1A and the dome-shaped mesh. The portion 9 _3A and the dome-shaped mesh portion 9 _2A are formed in the order of increasing size. Although not shown, the other control grids 8 _1A and 8 _3A are also formed to have exactly the same configuration. The dome-shaped mesh portions 9 _1A , 9 _2A , 9 _3A and their mesh openings are
The control grid 8 _2A can be formed in the same process as the press forming process.

According to this structure, the electron beams passing through the dome-shaped mesh portions 9 _1A , 9 _2A , and 9 _3A by applying substantially the same control voltage to the control grids 8 _1A , 8 _2A , and 8 _3A , respectively. Can be adjusted according to the emission brightness of each of the fluorescent screens 5G, 5B, 5R, so that a uniform color balance can be obtained.

In the above-described embodiment, the mesh openings of the dome-shaped mesh portions 9 _1A , 9 _2A and 9 _3A formed in the electron passage portions of the control grids 8 _1A , 8 _2A and 8 _3A are circular. Although the case has been described, the present invention is not limited to this, and it is needless to say that the same effect as described above can be obtained even if it is formed in a polygonal shape such as a triangular shape, a quadrangular shape, or a hexagonal shape.

Further, in the above-mentioned embodiment, the case where the dome-shaped mesh portions 9 _1A , 9 _2A and 9 _3A are provided in the electron passage portions of the control grids 8 _1A , 8 _2A and 8 _3A respectively has been described. The invention is not limited to this, and FIG.
It goes without saying that the same effect as described above can be obtained even if the opening diameters of the electron passage holes 9 ₁ , 9 ₂ and 9 _{3 shown} by are changed depending on the luminous efficiency of the phosphor screen.

[0011]

As described above, according to the present invention,
By making the aperture diameter of the electron passage portion of the control grid different according to the luminous efficiency of each phosphor screen, the amount of electron beams passing through the electron passage portion of the control grid is controlled, and a uniform color balance can be obtained. The conventional control circuit for changing the voltage applied to each control grid is unnecessary or simplified, and a large screen color display device can be realized at low cost, which is an extremely excellent effect.

[Brief description of drawings]

FIG. 1A is an enlarged plan view of an essential part showing a configuration according to an embodiment of an electronic device according to the present invention, and FIG. 1B is a line A- in FIG.
It is the top view seen from the A'line.

FIG. 2A is a plan view showing a basic structure of a conventional light source display tube, and FIG. 2B is a sectional view taken along line AA ′.

FIG. 3 is an exploded perspective view of a part of FIG.

4A is an enlarged cross-sectional view of an essential part showing the configuration of a conventional light source display tube, and FIG. 4B is a plan view taken along the line AA ′ of FIG.

[Explanation of symbols]

1 Vacuum Enclosure 2 Front Panel 3 Rear Panel 4 Cylindrical Side Plate 5 Fluorescent Display 5G Fluorescent Surface 5B Fluorescent Surface 5R Fluorescent Surface 6 Anode Electrode Group 7 Cathode Electrode Group 8A Grid Electrode Group 8 _1A Grid Electrode 8 _2A Grid Electrode 8 _3A Grid electrode 9 _1A Dome mesh part 9 _2A Dome mesh part 9 _3A Dome mesh part 10 Back electrode group 11 Electron beam 12 Lead pin 13 External terminal 14 Frit seal

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Zenichiro Hara 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi Electric Corporation Nagasaki Works (72) Inventor Shunichi Futashi 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi Electric Co., Ltd. Nagasaki Works (72) Inventor Kozaburo Shibayama 6-14 Maruo-cho, Nagasaki City, Nagasaki Prefecture Mitsubishi Electric Co., Ltd. Nagasaki Works

Claims (1)

Claim: What is claimed is: 1. A vacuum envelope in which a front panel is attached to the front surface of a tubular side plate, and a back panel is attached to the back surface of the tubular side plate in an airtight manner, and fluorescent screens are arranged in a matrix on the inner surface of the front panel. Fluorescent display unit, an anode electrode group composed of a plurality of accelerating anodes arranged around each of the fluorescent screens, and a cathode electrode in which an electron emission cathode is independently arranged for each of the fluorescent screens. Group, the cathode electrode group and the fluorescent display unit are arranged in the row (or column) direction corresponding to each fluorescent screen of the fluorescent display unit, and the electrons from each cathode pass as an unfocused beam. A grid electrode group including a plurality of control grids each having an electron passage portion, and a plurality of grid electrode elements arranged in the column (or row) direction on the back surface side of the cathode electrode group corresponding to each phosphor screen of the fluorescent display portion. Back of Each of the control grids of the grid electrode group and the back surface, the back electrode group including electrodes, and a lead pin having one end connected to each of the electrode groups and the other end penetrating the back panel and being pulled out to the outside. In a light emitting device in which each back electrode of an electrode group forms a matrix, the opening diameter of an electron passage portion of the control grid is made different according to the luminous efficiency of each of the fluorescent screens.