JPS60185343A - Planar display device - Google Patents

Abstract

PURPOSE:To take out an uniform electron beam from a linear cathode by forming the back face electrode for emitting the electron beam forward while holding the linear cathode with a resistor and stripe electrodes crossing perpendicularly with the linear cathode. CONSTITUTION:A planar display device is formed with a back face electrode 31, a linear cathode 35, an electron beam take-out electrode 36 and vertical deflection electrode, horizontal focus electrode, other control electrode group and light emission means. Here, the back face electrode 31 is formed by depositing In2O3 film uniformly onto the surface of a glass substrate as a resistor film 32 while providing the stripe electrodes 34 crossing perpendicularly with the cathode 35 on the resistor film 32. Then proper voltage is applied respectively onto the lead electrode 33 of the resistor film 32 and the stripe electrode 34. Consequently, the potential distribution in the longitudinal direction under operation of the linear cathode 35 is corrected to produce uniform electron beam thus to improve the display quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of Industry-4= The present invention relates to a flat panel display device using an electron beam.

An example of a basic configuration of an image display device used here will be described in detail with reference to FIG. 1, in detail the configuration of the conventional example and its problems.

This display element includes, in order from the back to the front, a back electrode 1, a line cathode 2 as a beam source, and vertical focusing electrodes 3, 3'.
, a vertical deflection electrode 4, a beam flow control electrode 5, a horizontal focusing electrode 6, a horizontal deflection electrode 7, a beam acceleration electrode 8, and a screen plate 9. ) is housed inside a vacuum chamber.

Here, a vertical focusing electrode 3 is used as an electron beam extraction means and a beam flow control electrode 6 as an electron beam control means.
vertical and horizontal deflection electrodes 4 and 7 as electron beam deflection means;
The screen plate 9 corresponds to each light emitting means.

A line cathode 2 as a beam source is stretched in the horizontal direction so as to generate an electron beam distributed linearly in the horizontal direction, and a plurality of such line cathodes 2 are arranged vertically at appropriate intervals. In the figure, only four wires, 2i to 22 (indicated by 1 to 2) are provided. In this embodiment, 15 wires are provided. It will be from 2 to 2 evenings. These line cathodes 2I
For example, an oxide cathode material is coated on the surface of a tungsten wire having a diameter of 10 to 20 /jφ.As will be described later, electron beams are emitted sequentially from the upper wire cathode 2a for a fixed period of time. (The back electrode 1 suppresses the generation of electron beams from other line cathodes 2 other than the line cathode 2 which is controlled not to emit electron beams for a certain period of time, (The back electrode 1 is attached to the inner surface of the rear wall of the glass bulb and is formed of a coating film of a conductive material.) That's fine. Instead of these back electrode 1 and line cathode 2, a planar electron beam emitting cathode may be used.

The vertical focusing electrode 3 is a conductive plate 11 having a horizontally long thread 1o facing each of the line cathodes 2a to 2b.
The electron beam emitted from the line cathode 2 is taken out through the slot 71-10 and focused in the vertical direction. (The slit 10 may be provided with crosspieces at appropriate intervals in the middle, or at small intervals in the horizontal direction (
The slits may be formed by rows of through holes provided on multiple sides at intervals of almost touching each other). The vertical focusing electrode 3' is also similar.

A plurality of vertical deflection electrodes 4 are arranged horizontally at intermediate positions of the slits 10, and conductors 13, 13 are provided on the upper and lower surfaces of the insulating substrate 12.
' is provided. Then, a vertical deflection voltage is applied between the opposing conductors 13 and 13' to deflect the electron beam in the vertical direction. In this embodiment, the electron beam from one line cathode 2 is vertically deflected to a position corresponding to 16 lines by a pair of conductors 13, 13'. The 16 vertical deflection electrodes 4 constitute 16 pairs of conductors corresponding to each of the 15 line cathodes 2, so that 240 horizontal lines are drawn on the screen 9. Deflect the electronic beano.

Next, the control electrode 6 is composed of a conductive plate 15 having a vertically long slit 14, and a plurality of conductive plates 15 are arranged in parallel in the horizontal direction at predetermined intervals. In this embodiment, 320 control electrode conductive plates 16a to 16n are provided (only 10 are shown in the figure). (This control electrode 5 extracts the electron beam horizontally by dividing it into one picture element at a time, and controls the amount of electron beam passing through it according to the video signal for displaying each picture element.)
Therefore, if 320 control electrodes 6 are provided, 320 picture elements can be displayed per horizontal line. In order to display images in color, each picture element is displayed with phosphors of three colors, R, G, and H, and each control electrode 6 is provided with the R, G, and H phosphors.
G and B video signals are sequentially added. Unfortunately, 320 sets of video signals for one line are applied to the 320 profit electrode plates 6 at the same time, and the video for one line is displayed at the same time.

The horizontal focusing electrode 6 is composed of a conductive plate 17 that covers a plurality of vertically long slits 16 of 320 mm opposite to the slits 14 of the control electrodes. are focused horizontally into a narrow electron beam.

The horizontal deflection electrode 7 is composed of a plurality of conductive plates 18 arranged vertically in the middle of each of the slits 16, and a horizontal deflection voltage is applied between each conductive plate 18. The electron beams for each picture element are deflected in the horizontal direction, and the R, G, and B phosphors are sequentially irradiated on the screen 9 to cause them to emit light. In this embodiment, the deflection range is the width of one picture element for each electron beam.

The acceleration electrode 8 is composed of a plurality of conductive plates 19 provided horizontally at the same position as the vertical deflection electrode 4.
The electron beam is accelerated to collide with the screen 9 with sufficient energy.

The screen 9 is composed of a phosphor 20 that emits light when irradiated with an electron beam is coated on the back surface of a glass plate 21, and a metal back layer (not shown) is added thereto. The phosphors 20 are divided into sections in the horizontal direction for one slit 14 of the control electrode 5, and the phosphors of the three colors R2O and B respond to each one electron beam struck. They are provided in pairs and applied vertically in stripes.The broken lines drawn on the screen 9 in FIG. 1 correspond to each of the plurality of wire cathodes 2, and are The two-dot chain line indicates the division in the vertical direction, and the two-dot chain line indicates the division in the horizontal direction where the plurality of control electrodes 6 are displayed correspondingly. As shown in the enlarged view in Figure 2, in the horizontal direction, the R and G of one picture element are
, B, and covers a width of 16 lines in the vertical direction. The size of one section is, for example, 1 mm in the horizontal direction and 16 mm in the vertical direction.

Please note that in FIG. 1, the horizontal length is greatly expanded relative to the vertical direction for clarity.

Further, in this embodiment, only one pair of R, G, and H phosphors 20 for one picture element is provided for one control electrode 6, that is, one electron beam, but for two or more picture elements. Of course, two or more pairs of picture elements may be provided, and in that case, the control electrode 6 has two or more pairs of picture elements R, , G.

B IS @signs are added sequentially, and horizontal deflection is performed in synchronization with it.

The flat panel display device described above has the following problems. Since the plurality of wire cathodes 2 are coated with oxide cathode material, the wire cathodes 2 must be maintained at a high temperature of about 600°C to ○0°C when taking out the electron beam. is necessary.

For this reason, a voltage is applied to both ends of the wire cathode to flow a current (heater current) to maintain the wire cathode 2 at a high temperature. When an electron beam is extracted with this ox\, since a voltage is applied to both ends of the line cathode 2, the voltage value differs for each part in the length direction of the line cathode, and the electron beam is uniform across the length. It becomes difficult to obtain beam current. Unfortunately, only when taking out the electron beam, even if the voltage value at both ends of the line cathode is equalized without passing the heater current temporarily, the length of the line cathode will be reduced due to the electron beam current emitted from the line shade (event). Similar to the above, it is difficult to obtain a uniform electron beam current because a potential difference occurs partially in the direction, and there is a problem in that it is difficult to obtain a non-homogeneous image quality.

OBJECTS OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by forming a resistor on the back electrode means for emitting the electron beam forward, obtain a uniform electron beam current, and provide uniform image quality. It's about doing.

Furthermore, by forming a part of the resistor with a metal part, and by forming the resistor so that the resistor has a different area resistance, a more uniform electron beam current can be obtained. This makes it possible to provide even more uniform image quality.

DESCRIPTION OF THE INVENTION In order to achieve the object of the invention, the present invention is characterized in that a flat panel display device is configured as follows.

A flat panel display device includes a plurality of wire cathodes as an electron beam source, a back electrode means for driving the electron beam forward,
It is composed of an electron beam extraction means, an electron beam control means, and a light emitting means, and the back electrode means is composed of a resistor. Incidentally, a part of the resistor may be constructed of a metal part or a part having different sheet resistance.

As a result, a uniform electron beam current of 1.1 can be obtained.

DESCRIPTION OF EMBODIMENTS A detailed embodiment of the present invention will be described with reference to FIG. The configuration of this embodiment is as follows.

The back electrode means usually uses a glass plate 31 as a substrate. An I n 203 film is formed on the surface of the glass plate 310 by evaporation or the like to a uniform thickness using about 100 to 6000 people to form the resistor film 32 . This resistor film 32 does not necessarily have to be an In2O3 film.

For example, even if Au is deposited extremely thinly, a resistor film with extremely high resistance can be obtained. Well, on both ends of this resistor film 32,
The lead terminal electrode 33 is made of a thick film of Au or the like and is attached as a conductor. Assuming that the effective display area of this flat panel display device is 200 x 160 tri, stripe-shaped electrodes 34 made of a metal film such as Au or Ni are placed on the surface of the resistor film 320 of the back electrode means at intervals of about 70 edges, and are made of a metal film such as Au or Ni. The back electrode means is formed by adhering to the throat with a film thickness of about 3,000 people. Furthermore, a wire cathode 35 is arranged on the front surface at a distance of about 2 mm. This wire cathode 36 has a length of about 210 mm and is formed by placing an oxide cathode coating material on a tungsten wire of 20 to 26 lrmφ and placing a chair on it. 1, this line cathode 3
An electrode 36 for electron beam extraction means is arranged further in front of the electrode 5 . This electrode 36 has a plate thickness of 0.2 m, a diameter of the electron beam passage hole 37 of 0.37 g, φ, and a pitch of 1.
．． ○It is formed by Qi.

Hereinafter, an example of the electrode configuration in a size that reaches the light emitting means and 1
7 is the same as the conventional example.

Next, an example of operation in this configuration will be described. line cathode 35
A heater current of 30 to 4.0 mA is constantly applied to maintain the temperature at a high temperature of about 600 to 700°C. A voltage of 160 V is applied to one electrode of the lead terminal electrodes 33 at both ends of the resistor film 32 of the back electrode means, and 157 V to the other electrode. 1. One side of the striped electrode made of metal film is -6
8.5V and -67.5V to the other, and +soV to the electron beam extraction means electrode 36 (().

In this state, when a negative pulse voltage of -30 .mu. At this time, the emitted beam current density is approximately the same along the length of the line cathode, so that a uniform electron beam current is obtained.

As a result, the linear electron beam can always obtain a uniform current density after passing through the electron beam extraction means electrode 36 and further passing through other electrode means until it reaches the light emitting means.

The following 1- can be understood from the various models shown in FIG. 4a. The length of the line cathode 36 is L1 with the point A as the origin and the direction of point B as the X direction, the unit length is dx, and the diode 41
is connected after point B, and pulse voltage 42 is applied from the direction toward point B. If the resistance per length of the wire cathode 36 is Rx, and the emission current is E, then the potential difference (1) applied to the X point of the wire cathode 36 can be approximately expressed by the following equation.

Here, it is assumed that the direction in which the emission current flows through the wire cathode 36 is from point B to point A, and that a constant potential vA (negative pulse voltage) is applied to point A.

At this time, the =L notation can be expressed as a curve 43 in Figure 4. The vertical axis is the potential, and the horizontal axis is the length of the wire cathode, which is expressed as X. When the length x = L, the difference in electrons is VL, so the potential is vA-IvL.

Therefore, the potential difference between the electron beam extraction means electrode 36 and the line cathode 35 is not constant along the length of the line cathode 35, but differs by VL. Therefore, in order to compensate for this, by varying the potential of the back electrode means along the length direction in accordance with vL, it is possible to uniformly extract the electron beam current. Still another example is shown in Figure 6 (,)
, (1)) and (C).

51 in FIG. 5(-) is an In
A resistor film 32 of 2O3 or the like is deposited by continuously changing the film thickness in accordance with the curve 43, and by continuously changing the sheet resistance along the length direction of the linear cathode 35. This is an example of a back electrode means.

52 in Figure 5 (1), like 51, has a film thickness of 1 in the Soviet Union.
4 - Vapor deposition is performed by continuously changing the resistance, but by depositing another resistor film 38, such as an extremely thin film of Al, in the second layer, the sheet resistance changes significantly, and the potential difference between the line cathodes becomes significant. This is an example of a back electrode means that can be used in cases where the adhesion strength between the electrode substrate and the vapor deposition material is weak. When a semiconductor element such as a diode is connected to both ends of the wire cathode 36, the potential difference due to the emitted current in the length direction of the wire cathode 35 is as follows.
The distribution is nearly symmetrical around the center of the line cathode.

In this case, the resistor film of the back electrode means corresponding to the potential difference has a concave thickness distribution as shown at 63 in FIG. 6(C).

By continuously changing the film thickness of the resistor film and partially varying the area resistance as shown in the following, a sufficient force J can be applied to the continuous change in potential difference due to the emission current of the wire cathode. Accordingly, a more uniform electron beam current can be obtained. In this case, in order to always ensure the same potential in the direction perpendicular to the line cathode in the potential distribution of the resistor film H, a narrow strip (for example, 100 μm width) is formed on the metal part in the direction perpendicular to the line cathode. 15 type r (gain gain) has the effect that a more uniform distribution can be obtained and a more uniform electron beam current can be obtained even between the line cathodes.

From the above embodiment, the relationship between the potential of the back electrode means and an arbitrary point in the X direction is shown in FIG. Here, the two-dot chain line 61 shows the potential distribution using the conventional back electrode means, and shows that the potential is the same everywhere. In other words, a non-uniform electron beam current is obtained. The one-dot chain line 62 shows the case where a resistor is attached to the back electrode means and a potential difference is applied.
Compared to the conventional example, the electron beam becomes a straight line that is closer to the curve shown in FIG. 43, and a uniform electron beam current can be obtained. In addition, the dotted line 63 indicates a case where a resistor is attached to the back electrode means 1~, and a part of the metal part is placed between both ends of the resistor to mark the potential: Iyn L, and it is more than 62 above. Furthermore, a more uniform electron beam current can be obtained. The broken solid line 64 indicates that when a resistor is attached by partially varying the area resistance of the back electrode means and continuously changing the film thickness, a more uniform electron beam current can be obtained in a continuous manner. I can do it. From the above, there is an effect that uniform image quality can be obtained.

As mentioned in 1. As mentioned above, by arranging the metal parts in a striped pattern, the parts are always maintained at the same potential, so a uniform potential distribution can be obtained, and even between each line cathode. This has the effect of making it possible to obtain a high electron beam current.

Effects of the Invention As described above, the flat panel display device of the present invention provides a more uniform electron beam than a linear cathode, and a more homogeneous image can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a basic configuration example of a flat panel display device as a conventional example, FIG. 2 is an enlarged view of a screen plate of the same device, and FIG. 3 is a partial view of a device according to an embodiment of the present invention. External view, No. 4
5 is a partial cross-sectional view of an apparatus according to another embodiment of the present invention, and FIG. 6 is a diagram for explaining the effects of various embodiments of the present invention. This is a diagram. 31 ・Glass plate as substrate for back electrode means, 7 32 ・Resistor film, 33 Electrode for lead terminal, 34
・Metal part, 35 Line cathode, 36... Electrode for electron beam extraction means.

Claims (3)

[Claims] (1) A plurality of line cathodes as an electron beam source, back electrode means for emitting the electron beam forward across the line cathodes, electron beam extraction means for extracting the electron beam, and 1. A flat panel display device comprising an electron beam control means for controlling a beam, and a light emitting means for emitting light upon impact of the electron beam, and wherein the back electrode means is formed of a resistor. (2) A flat panel display device according to claim 1, characterized in that the resistor of the back electrode means is partially provided with a metal portion. (3) A flat panel display device according to claim 1, wherein the resistor of the back electrode means is formed so that one portion thereof has a different sheet resistance.