JP3136550B2 - Fluorescent display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display device constituting a large-screen display device used in, for example, a stadium, and more particularly to an electrode structure of a plate-like shield electrode for controlling the luminance of a light emitting pixel. is there.

[0002]

2. Description of the Related Art FIG. 3 is an exploded perspective view showing the structure of this kind of fluorescent display device, in which one cathode is arranged corresponding to two pixels. In addition, a cathode may be arranged orthogonal to each pair of control electrodes, and one cathode may correspond to two pixels. In the figure, 1a is a glass display unit having phosphor pixels 9 formed by applying a phosphor paint, 1b is a frame-shaped glass spacer, 1c is a substrate on which a control electrode is disposed, The display unit 1a, the spacer 1b, and the substrate 1c constitute a unit main body 1 as a vacuum container.

In FIG. 1, reference numeral 2 denotes a linear cathode formed on a substrate 1c, 3 denotes a scanning electrode as a first control electrode, 4 denotes a data electrode as a second control electrode,
These scanning electrodes 3 and data electrodes 4 are arranged as shown in FIG. Wirings 5 and 6 electrically connect the scanning electrodes 3 and the data electrodes 4 in the row direction or the column direction. Reference numeral 7 denotes a flat plate shield electrode in which an opening 8 corresponding to the phosphor pixel 9 is formed, and reference numeral 10 denotes an exhaust unit.

[0004] Incidentally, the lead portions of S ₁ to S ₄ scanning electrodes 3 in the row direction is connected in common in Fig. 4, D ₁ to D ₄
Is a lead portion of the data electrode 4 commonly connected in the column direction. FIG. 5 shows timings of signals applied to these lead portions S _{1 to} S ₄ and D _{1 to} D ₄ . FIG. 6 shows the relationship between S _{1 to} S ₄ and D _{1 to} D ₄ and pixels P _{11 to} P ₄₄ .

In such a configuration, the thermoelectrons emitted from the cathode 2 behave in accordance with the combination of the potentials of the scanning electrode 3 and the data electrode 4. The behavior of the thermoelectrons will be described with reference to FIGS.

(1) The scanning electrodes 3 (for example, the lead-out portions S _{1 of the} scanning electrodes) connected in the row direction and the data electrodes 4 (for example, the lead-out portions D of the data electrodes) connected in the column direction.
₁ ) are both at a positive potential with respect to the cathode 2 and the other scanning electrode 3 (for example, the lead portion S _{2 of the} scanning electrode) is at a negative potential.
7A are deflected by the potential of the scanning electrode 3 as shown by reference numerals in FIG. 7A, pass through a predetermined opening 8 and reach the display section 1a serving as an anode, and the fluorescent pixel 9 (For example, the pixel P _{11 in} FIG. 6) is caused to emit light.

(2) When the scanning electrode 3 has a positive potential and the data electrode 4 has a negative potential, the potential near the cathode becomes negative due to the negative potential of the data electrode 4 closer to the cathode 2 than the scanning electrode 3. Thus, emission of thermoelectrons is suppressed (FIG. 7B).

(3) When the scanning electrode 3 (for example, the lead portion S _{2 of the} scanning electrode) has a negative potential and the data electrode 4 has a positive potential, there are the following two cases. (A) When the other scan electrode (the lead portion S _{1 of the} scan electrode sandwiching the data electrode 4 with respect to the scan electrode 3) is positive, the thermoelectrons emitted from the cathode 2 emit the other scan electrode. The fluorescent pixel 9 is deflected to the side (for example, FIG.
The pixel P ₂₁ ) does not emit light (a in FIG. 7A). (B) When the other scan electrode is also at a negative potential (for example, the relationship between the lead portion S ₃ of the scan electrode and the lead portion S ₄ of the scan electrode in the figure), the potential of the data electrode 4 is positive, Since the area of the electrode 4 is smaller than the area of the scanning electrode 3, the scanning electrodes 3 on both sides of the data electrode become negative near the cathode due to the negative potential, thereby suppressing the emission of thermoelectrons. No (b in FIG. 7A).

(4) When both the scan electrode 3 and the data electrode 4 are at a negative potential (the lead portion S _{3 of} the scan electrode, the lead portion S ₄ of the scan electrode and the data electrode 4 are negative (FIG. 7B)
)), The potential near the cathode becomes negative, the emission of thermoelectrons is suppressed, and the phosphor pixels 9 do not emit light.
Therefore, the phosphor pixel 9 located at the boundary between the scanning electrode 3 to which the positive potential is applied and the data electrode 4 to which the positive potential is applied emits light.

[0010] In FIG. 6, for example, signal to the scan electrode lead portion S ₁ is applied, the selected pixel P ₁₁ to P ₁₄ is the data one of these or all through data electrode lead portions D ₁ to D ₄ Light is emitted according to the potential applied to the electrode 4. Since signals are sequentially applied to the scan electrode lead portions S _{1 to} S ₄ , an arbitrary display can be obtained by giving an arbitrary signal pattern to the data electrode lead portions D _{1 to} D ₄ .

[0011]

Incidentally, since the spacer 1b constituting the unit body 1 is a glass insulator, the surface is charged up by the collision of thermoelectrons. Generally, when the surface of the glass is kept at an anode potential of about 10 KV, the secondary electron emission rate is larger than 1, so that the inner surface of the vacuum vessel where thermal electrons collide is positively charged as shown in FIG.

The flat plate shield electrode 7 physically shuts off the anode side and the cathode side and prevents the potential on the anode side (about 10 KV) from directly reaching the cathode side (about 10 KV). The behavior (control) of electrons described above from the emission of electrons to the opening 8 of the flat plate shield electrode 7 and the behavior (acceleration) of electrons after passing through the opening 8 are functionally separated. Become.

For this reason, as shown in FIG.
When b is positively charged, a difference is generated in the electric field near the opening 8 (opening near the spacer) 8 at the periphery of the flat plate shield electrode 7 and the opening 8 at the center, and goes from the opening 8 toward the anode. There will be a difference in the amount of electrons. In the case of FIG. 8, the vicinity of the spacer 1b is equivalent to the state in which the anode approaches the cathode side. Therefore, the amount of electrons emitted from the opening in the vicinity of the spacer 1b increases. It emits light brighter than the phosphor pixels.

As described above, in the conventional structure, the influence of the anode potential on the vicinity of the opening of the flat plate shield electrode is different between the peripheral wall portion of the vacuum vessel and the central portion side. There is a problem in that the brightness with the pixels varies, thereby deteriorating the display quality.

As a solution to such a problem,
As shown in FIG. 9, by making the area of the opening 8 at the center of the flat plate shield electrode 7 different from the area of the opening 81 at the periphery, variation in the luminance of each phosphor pixel is prevented. A fluorescent display device has been proposed (Japanese Patent Application No. 2-244533).

However, since there is a correlation between the area of the opening of the flat plate shield electrode 7 and the spread area of the electron beam, the light emission of the phosphor pixel corresponding to the portion where the opening of the flat plate shield electrode 7 is small. There was a problem that the size became smaller. Also, since there is a correlation between the area of the opening and the amount of electrons emitted from the opening, the design is such that the area and brightness (depending on the amount of electrons) of the phosphor pixels cannot be independently varied. There were restrictions.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to reduce the influence of a change in the electric potential of the inner surface of a vacuum vessel and obtain a stable fluorescent display device. Is to provide. It is another object of the present invention to provide a fluorescent display device capable of preventing a non-uniformity of luminance due to a variation in an electron collision position with respect to each phosphor pixel and further improving a display quality. .

[0018]

In order to achieve the above object, a fluorescent display device according to the present invention forms an opening of a plate-shaped shield electrode in a mesh shape and arranges the mesh-shaped opening in a matrix arrangement . From the center
The mesh opening ratio of the portion is reduced .

[0019]

The plate-shaped shield electrode according to the present invention equalizes the amount and diffusion of electrons from the opening toward the corresponding phosphor pixel.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an enlarged perspective view of a main part showing the configuration of a plate-shaped shield electrode according to an embodiment of the fluorescent display device according to the present invention.
In the same figure, a plate-shaped shield electrode 7A arranged to face the cathode 2 formed on the substrate 1c has openings 8A facing the phosphor pixels 9 formed in a mesh shape.
The four openings 8a at the center are formed with a larger mesh opening ratio, and the twelve openings 8b at the periphery are formed with a smaller mesh opening ratio than the center opening 8a. ing. Note that, in this case, the line width of the mesh forming each opening 8A has substantially the same size.

In such a configuration, by forming each opening 8A of the plate-shaped shield electrode 7A in a mesh shape, the effect of blocking the anode electric field of the plate-shaped shield electrode 7A is increased, and the potential of the outer surface of the vacuum vessel is reduced. The amount of thermionic electrons does not change even when the potential of the inner surface changes due to the change in, and a stable operation can be obtained.

In such a configuration, the plate-shaped shield electrode 7A is formed such that the opening 8b in the peripheral portion is formed to have a smaller mesh opening ratio than the opening 8a in the central portion, so that the opening in the peripheral portion is formed. Since the amount of the thermoelectrons emitted from 8b and its diffusion are suppressed, the amount of the thermoelectrons toward the corresponding phosphor pixel and the diffusion thereof are substantially equalized to the opening 8a at the center, so that each Phosphor pixel 9
As a result, almost the same brightness without variation in light emission luminance can be obtained.

FIG. 2 is a plan view of an essential part for explaining a configuration of a plate-like shield electrode according to another embodiment of the fluorescent display device according to the present invention. 2A, the opening 8A formed in the periphery of the plate-shaped shield electrode 7A has the same numerical aperture as the central opening 8a shown in FIG. 2A, as shown in FIG. 2B. An opening 8c having a small aperture ratio may be formed by increasing the line width of the mesh, and an opening having a small aperture ratio by reducing the mesh pitch while maintaining the same line width as shown in FIG. also form a part 8d not good.

In such a configuration, the same effect as described above can be obtained, and the amount of electron emission and electron diffusion passing through each opening 8A toward the anode can be reduced by the central opening 8a and the peripheral opening. 8c, 8d and 8e can be freely selected independently.

In the above-described embodiment, the case where the mesh shape of the opening 8A is formed in a lattice shape has been described. However, the present invention is not limited to this shape, and for example, a polygonal shape such as a hexagonal shape. Alternatively, the same effect as described above can be obtained even if the shape is circular or elliptical.

[0026]

As described above, according to the present invention,
Since the opening of the plate-shaped shield electrode is formed in a mesh shape, the amount of thermoelectrons due to a change in the potential of the inner surface of the vacuum vessel does not change, and a stable operation can be obtained. In addition, since the mesh aperture ratio is different between the central portion and the peripheral portion in the matrix arrangement of the mesh-shaped openings, the amount of thermoelectrons from each opening to the corresponding pixel and the diffusion thereof can be equalized, so that the luminance variation This is an extremely excellent effect that a fluorescent display device having no display quality and excellent in display quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a plate-shaped shield electrode showing a configuration according to an embodiment of a fluorescent display device according to the present invention.

FIG. 2 is a plan view showing another embodiment of the opening of the plate-shaped shield electrode according to the present invention.

FIG. 3 is an exploded perspective view showing a configuration of a conventional fluorescent display device.

FIG. 4 is a plan view showing a substrate in a conventional fluorescent display device.

FIG. 5 is a diagram showing a signal time chart in the fluorescent display device.

FIG. 6 is a plan view of the fluorescent display device as viewed from the front side.

FIG. 7 is a diagram for explaining the behavior of thermoelectrons in the fluorescent display device.

FIG. 8 is a diagram illustrating a problem of a conventional display unit.

FIG. 9 is a perspective view showing a configuration of a plate-shaped shield electrode proposed in recent years.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Unit main body 1a Display part 1b Spacer 1c Substrate 2 Linear cathode 3 Scan electrode 4 Data electrode 7A Plate shield electrode 8A Opening 8a Opening 8b Opening 8c Opening 8d Opening 9 Phosphor pixel 10 Exhaust part 30 Lead out External electrode S ₁ Leader of scan electrode S ₂ Leader of scan electrode S ₃ Leader of scan electrode S ₄ Leader of scan electrode D ₁ Leader of data electrode D ₂ Leader of data electrode D ₃ Leader of data electrode Part D ₄ Leader of data electrode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-995 (JP, A) JP-A-1-235148 (JP, A) JP-A-63-125352 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) H01J 31/12

Claims (1)

(57) [Claims] A cathode disposed on a substrate in such a manner that each pixel or a plurality of pixels is disposed on a substrate in a vacuum vessel having a display section in which pixels made of a phosphor are arranged in a matrix. A fluorescent display device including a plate-shaped shield electrode having an opening formed at a position corresponding to each of the pixels between the display unit and the substrate and a control electrode for controlling a flow of thermoelectrons emitted by the cathode, The openings of the plate-like shield electrode are formed in a mesh shape, and the mesh arrangement of the mesh-like openings is arranged in a matrix .
Fluorescent display device comprising this <br/> and having a small mesh opening ratio of the peripheral portion from the center portion are.