JPH05299041A - Fluorescent display device - Google Patents

Abstract

PURPOSE:To correct a difference in a corresponding positional relationship between phosphor picture elements and opening parts by providing step parts in the peripheral parts continuing to the central part of a platelike shield electrode, and providing the opening parts in the inclined parts of these step parts. CONSTITUTION:In cathodes 2 formed on a substrate and an oppositely arranged platelike shield electrode 7A, step parts 71 formed of the projecting parts 7c and the inclined parts 7d being inclined continuously to these projecting parts 7c are formed integrally on the peripheral parts containing the lead pullout side opening parts 8 so as to surround the central part 7a. In this constitution, since a distance D between the cathodes 2 and the opening parts 8 of the plate like shield electrode 7A becomes almost equal to each other in the central part 7a and the peripheral parts 7b, a corresponding positional relationship between phosphor picture elements 9 and the opening parts 8 can be corrected in a condition where a quantity of electrons emitted from the opening parts 8 is still uniform. Thereby, a quantity of thermoelectrons colliding with the respective phosphor picture elements 9 can be uniformized.

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-shaped shield electrode for controlling the brightness of light emitting pixels. is there.

[0002]

2. Description of the Related Art FIG. 3 is an exploded perspective view showing a structure of a fluorescent display device of this type, showing a case where one cathode is arranged corresponding to two pixels. In addition, a cathode may be arranged orthogonally 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 coating, 1b is a frame-shaped glass spacer, 1c is a substrate on which control electrodes are arranged, The display unit 1a, the spacer 1b and the substrate 1c constitute a unit body 1 which is a vacuum container.

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

[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-out portion of the data electrodes 4 which are commonly connected in the column direction. Timings of signals applied to the lead-out portions S _{1 to} S ₄ and D _{1 to} D ₄ are shown in FIG. FIG. 6 shows the relationship between S _{1 to} S ₄ and D _{1 to} D ₄ and the pixels P _{11 to} P ₄₄ .

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

(1) The scanning electrodes 3 connected in the row direction (for example, the extraction portion S _{1 of the} scanning electrode) and the data electrodes 4 connected in the column direction (for example, the extraction portion D of the data electrode)
₁ ) both have a positive potential with respect to the cathode 2 and the other scanning electrode 3 (for example, the scanning electrode lead-out portion S ₂ ) has a negative potential, the positive potential of the data electrode 4 causes the cathode 2
The thermoelectrons emitted from the device are deflected by the potential of the scanning electrode 3 as shown by the symbol in FIG. 7 (a), pass through a predetermined opening 8 and reach the display unit 1 a that is an anode, and the phosphor 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 which is closer to the cathode 2 than the scanning electrode 3. Therefore, the emission of thermoelectrons is suppressed (see FIG. 7B).

(3) When the scan electrode 3 (for example, the lead-out portion S _{2 of the} scan electrode) has a negative potential and the data electrode 4 has a positive potential, there are the following two cases. (A) When the other scanning electrode (the lead-out portion S _{1 of the} scanning electrode sandwiching the data electrode 4 with respect to the scanning electrode 3) is positive, the thermoelectrons emitted from the cathode 2 generate the other scanning electrode. The phosphor pixel 9 (for example, as shown in FIG.
Pixel P ₂₁ ) does not emit light (a in FIG. 7A). (B) When the other scanning electrode is also at a negative potential (for example, the relationship between the scanning electrode lead-out portion S ₃ and the scanning electrode lead-out portion S _{4 in the} figure), the potential of the data electrode 4 is positive, but the data 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 are negative in the vicinity of the cathode due to the influence of the negative potential, the emission of thermoelectrons is suppressed, and the phosphor pixel 9 emits light. No (b in FIG. 7A).

(4) When both the scan electrode 3 and the data electrode 4 have a negative potential (the scan electrode lead-out portion S ₃ , the scan electrode lead-out portion S ₄ 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 pixel 9 does 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.

In FIG. 6, for example, when a signal is applied to the scan electrode lead-out portion S ₁ , the pixels P _{11 to} P ₁₄ are selected, and one or all of these pixels are read through the data electrode lead-out portions D _{1 to} D _4. It emits light according to the potential applied to the electrode 4. Since signals are sequentially applied to the scan electrode lead-out portions S _{1 to} S ₄ , an arbitrary display can be obtained by giving an arbitrary signal pattern to the data electrode lead-out portions D _{1 to} D ₄ at that time.

[0011]

However, when a large-screen display device is constructed, since a large number of fluorescent display devices are arranged, the lead-outer external electrodes 30 provided on the substrate 1c are prevented from coming into contact with each other. As shown in (3), the spacers 1b of the unit main body 1 are tapered so as to secure a space between the substrates 1c of the adjacent unit main bodies 1. Therefore, in the peripheral portion on the lead lead-out side, the positional relationship between the opening 8 of the cathode 2 or the flat plate shield electrode 7 and the phosphor pixel 9 of the anode is displaced by an amount corresponding to the taper of the spacer 1b, and the phosphor pixel 9 is formed. On the other hand, there is a problem in that the position where the thermoelectrons collide with is shifted, and each pixel does not emit light with uniform brightness, resulting in a display in which variations are noticeable.

As a solution to such a problem,
The deviation of the corresponding positional relationship between the phosphor pixel 9 and the opening 8 of the flat shield electrode 7 due to the taper of the spacer 1b is corrected by tapering the peripheral portion of the flat shield electrode 7. Has proposed a fluorescent display device in which the brightness of each phosphor pixel 9 is made uniform (Japanese Patent Application No. 2-244533).

However, when the peripheral portion of the flat plate shield electrode is tapered, the distance between the cathode and the opening portion of the flat plate shield electrode is different between the central portion and the peripheral portion, and the distance from the opening portion to the anode side is increased. There is a problem that a difference occurs in the amount of electrons traveling, the amount of electrons emitted from the opening in the peripheral portion increases, and the pixel in the peripheral portion becomes brighter than other pixels. Further, when the pixel array has a high density, it is necessary to perform the above-described position correction not only on one peripheral row but also on a plurality of peripheral rows. In this case, there is a problem that the phenomenon that the surrounding pixels become brighter is further emphasized.

Therefore, the present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to prevent non-uniformity in luminance due to variations in electron collision positions with respect to each pixel and display quality. Another object of the present invention is to provide a fluorescent display device capable of further improving the above.

[0015]

In order to achieve such an object, the fluorescent display device according to the present invention is provided with a step portion in the peripheral portion continuous with the central portion of the plate-shaped shield electrode, and the inclined portion of the step portion. It is provided with an opening.

[0016]

In the plate-shaped shield electrode according to the present invention, the distance between the opening and the cathode is substantially equal in the opening and the peripheral portion, and the shift in the corresponding positional relationship between the phosphor pixel and the opening is corrected. ..

[0017]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an enlarged cross-sectional view of an essential part showing the configuration of an embodiment of the fluorescent display device according to the present invention, and the same parts as those in the above-mentioned figures are designated by the same reference numerals. In the figure, the plate-shaped shield electrode 7A disposed on the substrate 1c so as to face the cathode 2 has a peripheral portion 7b including a lead lead-out side opening 8 surrounding the central portion 7a, and a flat portion of the central portion 7a. The stepped portion 7 ₁ is integrally formed with a projecting portion 7c projecting upward from the upper portion and an inclined portion 7d that is continuous with the projecting portion 7c and inclines downward toward the lower portion. The inclined portion 7d of the step portion 7 ₁ has a central portion 7a.
Distance D which is almost equal to the distance from the cathode 2 of the opening 8 of
And the opening 8 is formed.

In such a configuration, the distance D between the cathode 2 and the opening 8 of the plate-shaped shield electrode 7A is substantially the same in the central portion 7a and the peripheral portion 7b, so that the opening 8
While the amount of electrons emitted from the fluorescent substance pixel 9 remains uniform, the shift in the corresponding positional relationship between the phosphor pixel 9 and the opening 8 is corrected, and the amount of thermoelectrons that collide with each phosphor pixel 9 is made uniform. Therefore, it is possible to obtain substantially the same brightness without variation in the emission brightness of each phosphor pixel 9.

FIG. 2 is an enlarged sectional view of an essential part showing the structure of another embodiment (when the phosphor pixels 9 are arranged in an 8 × 8 array) of the fluorescent display device according to the present invention. Are given the same reference numerals. 1 is different from FIG. 1 in that the central portion 7 is provided in the peripheral portion 7b of the plate-shaped shield electrode 7B.
A two-step step portion including a first step portion 7 ₁ and a second step portion 7 ₂ is integrally formed continuously with a.
The stepped portion 7 ₁ and the second stepped portion 7 ₂ are respectively formed with protrusions 7c ₁ 7C ₂ and inclined portions 7 _d1 and 7 _d2 , and these inclined portions 7 _d1 and 7 _d2 have an opening 8 respectively. Has been formed.

The plate-shaped shield electrode 7 thus constructed
In B, even when the position correction for the shift of the corresponding positional relationship is performed over a plurality of columns of the openings 8 facing each phosphor pixel 9, the position correction can be performed while the amount of electrons remains uniform.

[0021]

As described above, according to the present invention,
Since it is possible to correct the shift in the corresponding positional relationship between the phosphor pixel and the plate-shaped shield electrode opening while keeping the distance between the cathode and the plate-shaped shield electrode constant, a fluorescent display with excellent display quality without brightness variations. It has an extremely excellent effect that the device can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a fluorescent display device according to the present invention.

FIG. 2 is a diagram showing the configuration of another embodiment of the fluorescent display device 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.

[Explanation of symbols]

1 unit body 1a display part 1b spacer 1c substrate 2 linear cathode 3 scanning electrode 4 data electrode 7A plate-shaped shield electrode 7B plate-shaped shield electrode 7a central part 7b peripheral part 7c projecting part 7c ₁ projecting part 7c ₂ projecting part 7d inclined part 7 _d1 inclined part 7 _d2 inclined part 7 ₁ first step part 7 ₂ second step part 8 opening 9 phosphor pixel 10 exhaust part 30 lead extraction external electrode S ₁ scan electrode extraction part S ₂ scan electrode extraction Part S ₃ Scan electrode lead-out part S ₄ Scan electrode lead-out part D ₁ Data electrode lead-out part D ₂ Data electrode lead-out part D ₃ Data electrode lead-out part D ₄ Data electrode lead-out part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Zenichiro Hara 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi Electric Corporation Nagasaki Works (72) Inventor Kozaburo Shibayama 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Prefecture Mitsubishi Electric Corporation Nagasaki Works

Claims (1)

[Claims] 1. A cathode disposed on a substrate in such a manner that each pixel or one of a plurality of pixels is disposed on a substrate in a vacuum container having a display unit in which pixels made of a phosphor are arranged in a matrix. In 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 the flow of thermoelectrons emitted by the cathode, A step portion protruding toward the pixel side and having an inclined portion is provided in a peripheral portion continuous with the central portion of the plate-shaped shield electrode,
The peripheral portion side opening is provided in the inclined portion, the distance between each opening of the plate-shaped shield electrode and the cathode is kept constant, and the positional relationship corresponding to the pixel and the opening is shifted. A fluorescent display device characterized in that