JPH07105879A - Flat image display device - Google Patents

Abstract

PURPOSE:To prevent the image quality deterioration around a screen end part in a flat image display device, and provide a homogeneous image display. CONSTITUTION:An insulating material 27 is interposed between a L-shaped sectional electrode support plate 28 with which an electron beam drawing electrode 3 makes contact and the electron beam drawing electrode 3, and a proper field correcting voltage is applied to the L-shaped sectional electrode support plate 28. Thus, the field correcting voltage is applied to the L-shaped sectional electrode support plate, whereby sufficiently effective electron beams are drawn from the electron beams on a screen end part through a prescribed electron beam drawing hole, and all the beams on the whole screen can be homogenized to improve the quality of image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel type image display device used for a television receiver, a computer terminal display device and the like.

[0002]

2. Description of the Related Art In recent years, active developments have been made on thinning of color image display devices, and in particular, conventional cathode ray tubes (CR
A flat panel image display device of the beam scanning system in which the distance from the cathode to the anode of the T) system is remarkably shortened is disclosed in JP-A-3-674.
Proposed by No.44 and others. This is to divide the screen on the screen into a plurality of sections in the vertical direction, deflect the electron beam in the vertical direction for each section to display a plurality of lines, and further divide the section in the horizontal direction into a plurality of sections. The R, G, and B phosphors are made to sequentially emit light for each section, and the amount of electron beam irradiation to the R, G, and B phosphors is controlled by a color image signal that is received. To display a television image.

For this reason, such a flat panel image display device includes an electrode unit in which a distance from a cathode to an anode is extremely shortened in a flat box type vacuum container and a linear hot cathode (hereinafter referred to as a line hot cathode) serving as an electron beam generation source. It is called a cathode). This electrode unit is provided with small-diameter holes or slits for controlling, focusing, and deflecting the electron beam emitted from the line cathode, and the electron beam is controlled by the holes and slit portions of each of the electrodes. The image is displayed by passing through and acceleratingly hitting the anode part to cause the phosphor coated on the anode part to emit light.

FIG. 2 is an exploded perspective view showing the internal structure of the flat panel image display device. In FIG. 2, 1 is a back electrode, 2 is a horizontally extended line cathode (only four are illustrated here), 3 is an electron beam extraction electrode, 4 to 8
Is an electrode group that performs signal control, focusing, deflection, and the like. By stacking these plate-shaped surface electrodes 3 to 8 with an insulator interposed therebetween,
The electrode unit 11 is configured. Reference numeral 12 is an electron beam extraction hole in the electron beam extraction electrode, and 13 is a line cathode 2.
The electron beam emitted from the electron beam is directed to a single electron beam by the hole 12 of the electron beam extraction electrode, and is focused and deflected by the electrodes 4 to 8 while being deflected. Small section of screen 14
To scan. Reference numeral 9 is the flat box type front glass container.
R on the inner screen portion 15 of the front glass container 9,
The G and B phosphors are printed and applied, and the metal back layer is formed and a high voltage is applied, and the electron beam is accelerated to high energy to excite the projecting phosphor to emit light to the metal back layer. . The electron beam 13 projects a portion of the image on the small section 14 of the screen portion in a luminescent manner, and similarly, another electron beam causes all the small sections such as the other small section 16 to project on a luminescent surface. An image is displayed. A back container 10 is united and sealed with the front glass container 9 and then evacuated to form a flat panel image display device.

FIG. 3 is an external perspective view of the sealed flat panel image display device. 9 is a front glass container, 10 is a back container,
This is baked and sealed with frit glass. Reference numeral 17 is an exhaust pipe for evacuating the inside of the container, 18 is a high voltage terminal of the anode, and 19 is an external extraction terminal for control of various electrodes constituting the electrode unit. By externally connecting a driving circuit, a signal processing circuit and the like to these terminal groups, the flat panel image display device exerts its function as a television receiver or a display device.

FIG. 4 is an external perspective view of a flat panel image display device in which a part of the front container of FIG. 3 is cut out to expose the internal assembled state.

The electrode unit 11 is fixed to the back container by a fixing screw 20 and a screw seat 21 for fastening the fixing screw 20 provided at a predetermined position of the back container 10.

[0008]

As shown in FIG. 2, the electron beam emitted from the linear cathode 2 is caused to pass through the electron beam extraction holes 12 of the electron beam extraction electrode 3 at the highest density so that the image quality of an image is improved. , Is an important issue in securing brightness.

However, the electron beam passing through the electron beam extraction hole around the end of the electron beam extraction electrode is at the end because it is inevitably different from the central part of the electrode plate in shape and electric field. It was easily affected and it was difficult to homogenize the beam amount and the beam directivity over the entire surface of the electrode plate.

FIG. 5 is a side sectional view showing an electrode supporting structure of a conventional flat panel image display device. Back container 1
The conductive plate coated on the inner surface of 0 constitutes the back electrode 1. The back electrode 1 serves to direct the electron beam emitted from the line cathode 2 to the front screen side. Therefore, a negative voltage V1 is applied to the back electrode.

Also, an electrode unit 11 (not shown in FIG. 5) including an electron beam extraction electrode 3 which is parallel to the back electrode 1 in a plane.
For mounting, the electrode unit 11 is fixed by a tightening screw seat 21, a space support base 22, an electrode support plate 23 having an L-shaped cross section, and a fixing screw 20, which are fixed to a predetermined position of the back container 10 by an adhesive frit 24. Is retained.

On the other hand, in the space between the electron beam extraction electrode 3 located at the lower end of the electrode unit 11 and the back electrode 1, a wire cathode 2 as an electron emission source is stretched in a plane parallel manner and the electron emission is facilitated. In order to make the line cathode 2 higher than the back electrode 1,
By applying an appropriate voltage lower than that of the electron beam extraction electrode 3, the electric field on the surface of the linear cathode 2 becomes positive and electrons are emitted, and the electrons are attracted toward the electron beam extraction electrode 3 to generate an electron beam source. Becomes

Contrary to the above, when a voltage higher than that of the electron beam extraction electrode 3 is applied to the line cathode 2, the line cathode 2
The electric field on the surface of becomes negative and the emission of electrons can be suppressed. Therefore, by individually controlling the voltage of the line cathodes, for example, an electron beam is repeatedly emitted from the upper part for a certain period of time repeatedly, and each line cathode has a sheet-like shape having a uniform current density in the horizontal direction. An electron beam can be generated.

The sheet-shaped electron beam is decomposed into a large number of beam rows in the horizontal direction by the electron beam extraction holes 12 to 12 "of the electron beam extraction electrode 3 and the like, and a large number of electrons are similarly extracted from other line cathodes. Beam row is electron beam extraction hole 1
It is generated by passing through 2. When these electron beams further proceed and pass through the through hole of the next signal electrode 4, the signal electrode 4
The passing amount of the electron beam is controlled by the pulse width modulation signal voltage that changes according to the video signal applied to the. The electron beam further proceeds to be focused, deflected, and accelerated to irradiate and emit the phosphor on the screen surface, thereby subdividing (1 in FIG. 2).
4) is emitted by one electron beam, and similarly, all electron beams are digitally combined to display a television image.

In the above operation principle, as described above, the quality of each electron beam generated at the electron beam extraction electrode, which is the earliest stage of the electron beam, has the greatest influence on the image quality of the image on the screen at the final stage. Will be received.

As shown in FIG. 5, the electron beam 13A passing through the end of the electron beam extraction electrode surface is in an environment different from that of other electron beam 13C, for example, in the shape and configuration around the end line cathode. Also, due to the edge effect, the electron beam extraction electrode tends to be drawn to the end side of the electrode, and the generated electron beam 13A is affected by the force attracted to the outside of the end through hole to There is a problem that a sufficient effective electron beam does not pass through the electron beam extraction hole 12 and the electron beam is inferior in quality to the electron beams at other positions, and eventually the image quality of the entire screen becomes uneven. Was.

[0017]

In order to solve the above problems, a line cathode as an electron beam source and a plurality of electrode plates are provided between a back electrode and a screen, and these are stacked and enclosed in a flat glass container. After that, the inside is evacuated, the electron beam is drawn out from the linear cathode, and among the plurality of electrode plates of the flat-panel image display device that controls and illuminates / colors the phosphor on the screen to display an image, An electron beam extraction electrode disposed closest to the wire cathode, an electrode support plate having an L-shaped cross section that abuts the electron beam extraction electrode with an insulator interposed, and a fixing screw that fixes the plurality of electrode plates. And an electrode support structure comprising a space support base fixed to the rear side container of the glass container having a fastening screw portion of the fixing screw with an adhesive frit, the electric field correction is performed on the electrode support plate having an L-shaped cross section. Know applying a voltage to bring the results.

[0018]

A negative voltage is applied to the electrode supporting plate having an L-shaped cross section to cause the electron beam, which is generated from the end line cathode and tends to be attracted to the outside, to be pushed back, and the electron beam extraction hole at the end part. It can perform the function of passing a sufficient amount of electron beam.

[0019]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, a space for supporting the back electrode 1, the electron beam extraction electrode 3, and the electron beam extraction electrode 3 which are installed so as to sandwich the line cathode 2A and the line cathode 2A, which are positionally extended at the ends. Electron beam extraction electrode with a support base 22, an electrode support plate 28 having an L-shaped cross section provided on the space support base 22, and an insulator 27 laid on the upper surface of the electrode support plate 28 having an L-shaped cross section. Electrode unit 11 assembled together with 3
(Not shown) is fastened and fixed by the fixing screw 20.
By applying a negative voltage to the electrode support plate 28 having an L-shaped cross section in the above configuration, an electric field for pushing back the attracted electron beam is generated, and the end electron beam is emitted from the predetermined electron beam extraction hole 12 in a sufficient amount. An effective electron beam can be extracted. In this embodiment, the insulator 27 is formed by spraying an alumina paint.

[0020]

EFFECTS OF THE INVENTION Since the electron beam that carries the image at the edge of the screen can be made into an effective electron beam which is qualitatively sufficient, it is possible to solve the luminance and color unevenness of the image and to homogenize the image quality of the entire screen. Can be done.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an electrode support structure in an embodiment of a flat panel image display device of the present invention.

FIG. 2 is an exploded perspective view of the device.

FIG. 3 is an external perspective view of the device.

FIG. 4 is a perspective view in which a front container of the device is partially cut away and an internal assembly state is exposed and displayed.

FIG. 5 is a side sectional view showing an electrode supporting structure of a conventional flat panel image display device.

[Explanation of symbols]

 1 Back Electrode 2 Wire Cathode 3 Electron Beam Extraction Electrode 10 Back Container 12 Electron Beam Extraction Hole 13 Electron Beam 22 Space Support Stand 27 Insulator 28 Electrode Support Plate with L-shaped Cross Section

Claims (2)

[Claims] 1. A line cathode as an electron beam source and a plurality of electrode plates are provided between a back electrode and a screen, these are laminated and sealed in a flat glass container, and then the inside is evacuated to obtain the line cathode. In a flat panel image display device that draws an electron beam from the substrate and controls it to irradiate and color the phosphor on the screen to display an image, the flat plate image display device is arranged closest to the linear cathode among the plurality of electrode plates. An electron beam extraction electrode, an electrode support plate having an L-shaped cross section that abuts on the electron beam extraction electrode with an insulator interposed, a fixing screw for fixing the plurality of electrode plates, and a tightening screw portion for the fixing screw. A flat plate type image display device, comprising a space support fixed to the back side container of the glass container having an adhesive frit by an adhesive frit, and applying a voltage to the electrode support plate having an L-shaped cross section. 2. The flat panel image display device according to claim 1, wherein the insulator is an alumina-based paint spray-coated on the electrode support plate having an L-shaped cross section.