JPS6093741A - Picture display device - Google Patents

Abstract

PURPOSE:To obtain a picture with uniform brightness by a method, in which the amount of an electron beam passing through the through holes drilled in the first electrodes is detected by the second holes drilled in the first electrode is detected by the second electrode, while a detected amount of change is fed-back to the rear electrode and the linear cathode for regulating picture quality. CONSTITUTION:A plate type picture display device has the constitution for obtaining an electron beam of good efficiency while being arranged from the back to the front in order of a rear electrode 31, a linear thermal cathode 32, an electron beam fetch electrode 33 and an electron beam focusing electrode. The electrode 31 and the cathode 32 are arranged at an interval of 2mm., while the cathode 32 and the electrode 33 are arranged at an interval of 3mm., further the electrode 33 and the electrode 34 are arranged at an interval of 0.4mm.. The electrode 33 and the electrode 34 are provided with the through holes 33a and the through holes 34a respectively while having the constitution, in which, for instance, 200 through holes of 0.5mm.phi and 0.8mm.phi are arranged. For instance, the electrode 31 is given -60V, the cathode 32 is given -30V of pulse voltage, while the electrode 33 is given 30V, the electrode 34 is given 0V voltage and the amount of the electron beam passing through the through hole 33a is detected by the electrode 34 and the electrodes subsequent thereto, while the changed amount detected is fedback to the electrode 31 and the cathode 32 thus being able to display a picture having uniform brightness.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image display device for displaying an image of a character, etc., and particularly relates to a specific configuration of an image display device for improving the image quality of the image display device. It is.

Structure of the conventional example and its problems FIG. 1 is a perspective view of a flat panel image display device previously proposed by the present inventors. This image display device includes, in order from the back to the front, a back electrode 1, a linear hot cathode 2 as a beam source,
Vertical focusing electrodes 3, 3', vertical deflection electrodes 4, beam flow control electrodes 5, horizontal focusing electrodes 6, horizontal deflection electrodes 7, beam acceleration electrodes 8, and screen plates 9 are arranged and configured, and these are arranged on a flat surface. It is housed within the evacuated interior of a glass bulb (not shown).

Here, a vertical focusing electrode 3 is used as an electron beam extraction means, a beam flow control electrode 5 is used as an electron beam control means, vertical and horizontal deflection electrodes 4 and 7 are used as electron beam deflection means, and a screen plate 9 is used as a light emitting means. It turns out.

A linear hot cathode 2 serving as a beam source is installed in the direction of the water in order to generate all the electron beams distributed linearly in the water direction. A plurality of them are provided in the direction (here, only four from 2-2 to 2-2 are shown). In this embodiment, it is assumed that 15 pieces are provided.

It will be from 2 to 2 evenings. These linear hot cathodes 2 are, for example, 1
An oxide cathode material is applied to the surface of the 0 to 20 Bφ T/Gester deposit. Then, as will be described later, the electron beams are controlled to be emitted sequentially from the upper linear hot cathode 2a for a fixed period of time.

(The back electrode 1 suppresses the generation of electron beams from other linear hot cathodes 2 other than the linear hot cathodes 2 that are controlled to emit electron beams for a certain period of time, and This back electrode 1 may be formed by a coating of electrically conductive material applied to the inner surface of the rear wall of the glass bulb.

The vertical focusing electrode 3 is a conductive plate 11 having horizontally long slits 10 facing each of the hot cathodes 2a to 2a, and the electron beam emitted from the linear hot cathode 2 is taken out by passing through all of the slits 10. .

and vertically focused. The slits 10 may be provided with beams at appropriate intervals in the middle, or may be a row of many through holes arranged horizontally at small intervals (so that they almost touch each other). It may also be configured as a slit.

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 and 1 are provided on the upper and lower surfaces of the insulating substrate 12, respectively.
3'. 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 hot cathode 2 is vertically deflected to a position corresponding to 16 lines by a pair of conductors 13 and 13'.

Then, the 16 vertical deflection electrodes 4 constitute 16 pairs of conductors corresponding to each of the 16 linear hot cathodes 2, and in the end, the electron beam is drawn so as to draw 240 horizontal lines on the screen 9. to deflect.

Next, each of the control electrodes sFi is constituted by a conductive plate 16 having a vertically long slit 14, and a plurality of control electrodes sFi are arranged in parallel in the horizontal direction at predetermined intervals. In this embodiment, 320 control electrode conductive plates 16a to 15n are provided. (Only 10 electrodes are shown in the figure.) (Each control electrode 5 divides the electron beam horizontally into one pixel and extracts it, and displays the amount of electron beam passing through each pixel.) ) Therefore, if 32,020 control electrodes 5 are provided, 320 picture elements can be displayed per horizontal line. Also,
In order to display images in color, each picture element is displayed using phosphors of three colors, R, G, and B, and the R, G, and B image signals are sequentially applied to each control electrode 6. It will be done. Also, 3
320 sets of video signals for one line are simultaneously applied to the 20 control electrodes 5, and the video for one line is displayed at one time.

The horizontal focusing electrode 6 is connected to the slit 14 and 16 of the control electrode 6.
It is composed of a conductive plate 17 having a conductive plate 17, and focuses the electron beams of each picture element divided horizontally into a narrow electron beam in the horizontal direction.

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 for each picture element. The electron beams are respectively deflected in the horizontal direction, and the R, C, and B phosphors are sequentially irradiated on the screen 9 so that they 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 has a phosphor 20 that emits light when irradiated with an electron beam applied to the back surface of a glass plate 21, and a metal back layer (not shown) is added at 4 to form a phosphor 20 (pattern 14).
1 For one slit 14, that is, for each one electron beam divided in the horizontal direction, phosphors of three colors R2H and B are applied. One pair of each are provided and applied vertically in stripes. The broken lines drawn on the screen 9 in FIG. Indicates the corresponding horizontal division.

Further, in this embodiment, it is of course possible to provide only one pair of R, G, and H phosphors 20 for one picture element for one control electrode 5, that is, for one electron beam. In that case, the control electrode 5 has R, G, B for two or more picture elements.
Video signals are applied sequentially, and horizontal deflection is performed in synchronization with the video signals.

Conventionally, flat panel display devices such as those described above have had the following problems.

The electrons emitted from the linear hot cathode 2 are pushed out by the back electrode 1 provided behind it toward the electron beam extraction means in front of it, and when they pass through the through hole provided in the electron beam extraction means. An electron beam is formed.

Further, the electron beam that has passed through the electron beam extraction means is focused and deflected by various electrodes at the rear and collides with the phosphor to display an image. Due to errors in assembly precision of the hot cathode 2 and electron beam extracting means 3, vibration of the linear hot cathode, etc., differences in brightness occur in each section, resulting in a reduction in image quality.

Therefore, the amount of electron beam reaching the fluorescent surface is determined by each linear hot cathode 2.
It is necessary to make adjustments for each area or each area.

However, the amount of electric current r emitted from the linear hot cathode 2 and the amount of electric f beam passing through the electron beam extracting means are not necessarily correlated. As is clear from Fig. 2, the cross-sectional distribution of the electron beam emitted from the linear hot cathode is bell-shaped, and the emission area of the electron beam changes as the voltage of the back electrode 1 changes. This is because the direct force distribution in the central portion from the linear hot cathode hardly changes.

Therefore, it was insufficient to detect the amount of electrons emitted from the linear hot cathode and adjust the brightness.

OBJECTS OF THE INVENTION An object of the present invention is to provide an image display device having an electrode structure capable of detecting the amount of electron beam in order to solve the above-mentioned problems.

Another object of the present invention is to provide an image display device with excellent image quality and particularly uniform brightness by using the electrode structure for detecting the amount of electron beam.

Structure of the Invention In order to achieve the above object, the present invention is characterized by configuring a display device with the following structure. The present invention adds an electron beam detection function to the conventional electrode configuration without changing its width. A beam passing hole other than the beam passing hole for image display is provided in the first electrode plate of the vertical focusing electrode plate, which is a conventional electron beam extraction means, and the beam passing amount is controlled by the second electrode plate behind it. It detects a voltage of 1° and a voltage corresponding to the detected amount of beam.
and feed current to other electrodes such as the linear hot cathode and the back electrode and the first electrode plate.

This is used to control the amount of beam passage for image quality display.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 3 is a sectional view of an electron source portion showing one embodiment.

In the figure, from the back electrode 31 to the linear hot cathode 32, to the electron beam extraction electrode 33. The electron beam focusing electrode 34 is placed in front of the electron beam focusing electrode 34 so as to obtain an efficient electron beam. In the embodiment, a back electrode 31 and a linear hot cathode 32
Limb 2 linear hot cathode 32 and electron beam extraction electrode 33
are arranged at a spacing of 3mM, and electrode 33 and electrode 3
4 is an interval of 0.4 hearings. The electrode 33 and the electrode 34 each have a through hole 33I! L and 34& are provided.

In the embodiment, 200 pieces of 0.5φ and 200 pieces of 0.8φm were arranged. In this configuration, for example, the back electrode 31 has a voltage of -6OV and the linear hot cathode 32 has a voltage of -50V.
V pulse voltage, 30V to the electron beam extraction electrode 33
When a voltage of 34 keV was applied to the electron beam focusing electrode 34, the current flowing into the electrode 33 and the electrode 34 was measured. Inflowing electrician G
2 was 1tnA.

Figure 4 shows the current IG flowing into the electron beam extraction electrode when the voltage applied to the back electrode is changed, the current flowing into the electron beam focusing electrode G2, and the grid electrode (not shown). current IG5, and the fluorescent surface (
3 shows the state of change in the electric current A flowing into the circuit (not shown).

As can be seen from the figure, the current IG flowing into the electron beam focusing electrode 34 at a voltage lower than the back electrode voltage -55'/
2, and the current flow G3 flowing into the lattice electrode and the current IA flowing into the fluorescent surface show a similar tendency with little change.

For this reason, the brightness of the fluorescent surface can be made uniform by using the electrode after the electron beam focusing electrode as a detection section and detecting the current flowing into the electrode. However, the current 1G2 flowing into the electron beam focusing electrode 34 has a small current value and it is difficult to detect the amount of change, so it is necessary to increase the absolute value of the current to be detected. Furthermore, since the current -3 flowing into the grid electrode changes in response to changes in the voltage applied to the vertical deflection electrode disposed in front of it, it is difficult to detect it as a change in brightness.

Next, other embodiments of the present invention will be described.

FIG. 6 shows through holes 5 formed in the electrodes of the electron beam extraction means in order to increase the amount of detected electron beams.
A through hole s3b for passing another electron beam is disposed between 3a and on the same axis, and the electron beam passing through this electron beam passing hole reaches the fluorescent surface, and the electrode behind it. 54V (detected as the amount of electron beam hitting the through hole 53b. It is desirable that the through hole 53b has a shape that does not affect the shape of the through hole 531L. In the embodiment, a Q2X2■ slit is used.The reason for this is, for example, When the through holes 63a are arranged at 1B pitch,
When the diameter of the through hole 53a is 0.5φ, the diameter of the through hole 53b is 0.5 mm, and the maximum diameter of the through hole 53b is 11?1, and C is 0.2 mm, including etching accuracy. Also, considering the vertical electron emission area, 2ruL is appropriate. The electrode configuration at this time may be the same as that of the previous embodiment, and the current value flowing into the electrode 54 when the driving conditions are the same is 0,
The amount of passage through the 2X2+1171L slit increases, approximately 2
mA, which is a value that can sufficiently detect changes in current value.

FIG. 6 shows another embodiment in which the through hole 63a formed in the electrode 63 of the electron beam +1y extraction means is entirely in the form of a slit. In the example described in n'+J, the through hole was shaped so as not to particularly cast a shadow Vt in the horizontal direction due to the electrode structure, but in this example, this restriction was removed,
The beam characteristics in the horizontal direction depend on other electrodes, and the slit shape was used to focus only on the beam characteristics in the vertical direction. Since the vertical distribution of electrons emitted from the linear hot cathode has a hanging glass distribution as described above, the beam characteristics in the vertical direction largely depend on the slit shape. Shipuha l -7
k 5 to one piece IξJI/7') Daytime spit d/pull? It is thought that the f-beam is incident almost perpendicularly to the electrode 63 of Miyo, and even if the f-beam is incident at a certain angle, the speed of the electrons is slow (eoeV). Characteristics can be maintained sufficiently by electrodes. For this reason, the through hole 63a is made into a q (lull) slit parallel to the linear hot cathode 62. This substantially increases the flow rate of 7μ flowing into the electrode 64, and in the embodiment, the flow rate is approximately smA. became.

Effects of the Invention The present invention uses an electrode for detecting the amount of electron beam as the second electrode of the electron beam extraction means, which has a proportional relationship with the amount of electrons flowing into the fluorescent surface, so that a current value corresponding to the brightness of the screen can be determined. By detecting the current value and feeding back the difference from the average value of the current value, it becomes possible to adjust the brightness, thereby making it possible to create a display device with uniform brightness over the entire screen.

Also, 1) the shell of the 11th electrode of the electron beam detection electrode;
By improving the ff hole shape, detection sensitivity can be substantially increased and brightness adjustment can be easily performed/C3゜

[Brief explanation of drawings]

Figure 1 is a perspective view showing the configuration of a conventional image display device;
The figure is a graph for explaining the distribution of electron beams in the same device, FIG. 3 is a sectional view showing the main parts of an image display device according to an embodiment of the present invention, and FIG. 4 is a graph showing changes in current in the device. 5 is a cross-sectional view showing the main parts of an image display device according to another embodiment of the present invention, and FIG. 6 is a cross-sectional view showing the main parts of an image display device according to still another embodiment of the present invention. . 31.51.61... Back electrode, 32, 62
. 62... Line hot cathode, 33.53.63...
...first electrode, 34.54.64...second
electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Mosquito light type section C Hanto I) Figure 3 Figure 4 Back cover Gokuki pressure EB (-v)

Claims (2)

[Claims] (1) A plurality of linear hot cathodes, a back electrode placed behind the linear hot cathodes, and a first back electrode placed in front of the linear hot cathodes.
and? In an image display device having a J2 electrode,
The second electrode detects the amount of electron beam passing through the through hole formed in the first electrode, and the detected change amount is fed back to the back electrode and the linear hot cathode to adjust the image quality. What to do f: Characteristic image display device. (2) The image display device according to claim 1, wherein the first electrode has an electron beam through hole other than the electron beam through hole for displaying the image 'f.