JPH02309540A - Electronic beam amplification unit, applied electronic beam amplifier using same and plane type display device - Google Patents

Abstract

PURPOSE:To improve brightness, withstand voltage property and productivity by applying material with the secondary electron multiplication factor being 1 or more such as frit glass on almost all faces of a metal thin-plate with open holes. CONSTITUTION:A metal thin-plate 31 is provided with a number of approximately circular open holes. The open holes in provided in number equivalent to the respective fluorescent elements on a fluorescent face in a horizontal direction and in number equivalent to frame scanning lines in a vertical direction. On all faces, i.e., the upper face, the lower face, and the open hole inside face, of the thin plate 31, frit glass 32 with the thickness being 5-30mum is applied. Three to four layers of the metal thin-plate 31 covered by the glass 32 are laminated and integrated and given reduction treatment at 300-400 deg.C in a hydrogen atmosphere to create lead glass. An integrated microchannel plate 9 is made into a high-resistance element to 10<6>-10<12>OMEGA, and at the same time made into a multiplier of high electronic beam amplification factor because the frit glass 32 on the inside face of open hole is material of high secondary electron emission ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of Application The present invention 1 relates to an electron beam amplification unit used in color television receivers, computer terminal displays, etc., and an electron beam amplification device and flat panel display device using the same. It is something.

Conventional technology Chika: Flat-plate image display devices are being actively developed, including liquid crystal displays (LCDs), electroluminescent displays (ELs), and light-emitting diode displays (
LED) etc. have appeared on the market and are inferior to Tecolor cathode ray tubes in terms of full color.

To solve these problems, JP-A-63-228
A flat panel display device using an electron multiplier disclosed in Japanese Patent No. 552 has been proposed.

This display device will be explained below with reference to FIG.

As shown by the broken line in the figure, a low-velocity (approximately 500 eV) and low-density (approximately 1 μA) electron beam (approximately 1 μA) is emitted from the electron gun 32.
The line is deflected by an electrostatic deflector 33. A plane electrode 35 provided on the back side of the divider 31 and a plane electrode 3 provided on the surface of the vacuum container facing the plane electrode 35.
Even if a potential of 1 to 400 V is applied between the line-deflected electron beam 1 and 6, the line-deflected electron beam 1 is fixed near the Ov potential draw-shaped electrode 37 at the upper end of the vacuum chamber (left end in the figure) by an electrostatic periodic lens. Go straight until the draw-shaped electrode 37
Even though an inversion lens is formed due to the potential difference between the plane electrode 35 and the plane electrode 35, the electron beam that has gone straight to the top of the vacuum chamber moves approximately in a circular motion due to this inversion lens. 4 The electron beam that has proceeded to the front part of the vacuum vessel (Friend Splitter 3I)
By changing the potential of a plurality of horizontally elongated and vertically divided electrodes 38 provided on the front side of the microchannel plate 34, which is an electron beam multiplier for frame scanning, The direction of travel can be changed.

6(a) and (b) for addressing the conventional microchannel plate 34.
) will be explained with reference to Figure 6(a)! i Microchannel plate 34
A metal plate with a thickness of 0.15 mm has a plurality of approximately circular holes 4 The cross-sectional shape of the holes is 0.42 mm for the large hole 61 and 0.42 mm for the small hole 62. It has an asymmetrical shape of .3mm. This (mainly uses the shadow mask of the current CRT) 4 The inner wall of the opening is coated with a material 63 with a high secondary electron emission ratio, such as magnesium oxide. Microchannel plate 3
4 (Top) The dynode electrode 64, which is made up of two metal plates facing each other with a large number of holes, is connected to a resistive or insulating 0.15 mm resistive or insulating electrode made of a small glass bulb known as, for example, Barochini. This is a structure in which a plurality of layers are stacked with spacers 66 in between.

philips journal of research
According to h-Vo141 No. 3 (P325-342'), when the dynode electrodes 64 are stacked in seven stages, the applied voltage is as follows: is 300V, and in this case, the potential difference between the first stage and the last stage is about 2k.
The electron beam incident on the desired opening of the microchannel plate 34 is amplified at an amplification factor of 3 to 3.3 times for each stage, and is finally amplified to approximately 500 to 700 times. However, with such a configuration (as a flat panel display device,
It is difficult to solve the problem of withstand voltage and obtain sufficient brightness.

Therefore, in order to obtain sufficient brightness (force to increase the current density of the electron beam emitted from the electron gun 32 \ force to increase the energy of the electron beam and substantially increase the amount of current \ or the current of the microchannel plate 34 Three techniques can be considered to increase the amplification factor: The first technique increases the current density of the electron beam emitted from the electron gun 32, increasing the beam radius of the IT electron beam. When the electron beam passes through an inverting lens, the aberration (spherical aberration) increases, and the shape of the electron beam becomes greatly distorted. ).The distorted electron beam 1 enters into holes other than the desired openings of the microchannel plate 34, causing a decrease in contrast and crosstalk.In addition, a second technique that increases the energy of the electron beam is used to increase the electrostatic charge on ζ. Although this method has the disadvantage of increasing the voltage applied to the type deflector 33 and the inverting lens, a third technique is required to increase the current amplification factor of the ζ microchannel plate 34 in order to improve the overall brightness.

By the way, in order to increase the current amplification factor of the microchannel plate 34 (to increase the number of laminated layers of the microchannel plate 34 ＼ force to increase the potential difference between one layer), there are three methods that increase the secondary electron multiplication factor of the inner wall of the opening. Further techniques can be considered.

However, according to the first technique of increasing the number of layers of the microchannel plate 34, the weight and cost increase, and the manufacturing difficulty also increases. It is clear that alignment of the holes provided in each dynode 64 in several layers over the entire surface of the microplate increases exponentially as the number of stacked layers increases, but it also seems to be the second technique. When the potential difference applied between each layer is increased, the electric field strength between each dynode 64 and 64 increases, and the withstand voltage characteristics deteriorate. In the case of the third technique, which increases the probability of discharge occurring and increases the current amplification factor of the microchannel plate by increasing the secondary electron multiplication factor of the inner wall of the aperture, the limit is the secondary electron multiplication factor. It is sufficient to apply a substance with a high electron emission ratio to the inner wall of the opening (unfortunately, there are currently commonly used substances that have a higher secondary electron multiplication ratio than MgO, are stable in vacuum, and are inexpensive). Flexible ~ Here, the inventors (yo) Microchannel plate 3
Regarding 4, there is a relationship between the size and cross-sectional shape of the opening in the thin metal plate, that is, the size of the large hole and the size of the small hole.Furthermore, there is an optimal value for the distance between the thin metal plates, and these are quadratic. We have come up with the idea that it will greatly contribute to the electron amplification factor.
As shown in Fig. 6(b), the secondary electrons of the electron beam incident on the first stage dynode 64 (a) are emitted from the metal side wall according to the cosine law, and due to the voltage applied between them and the next metal wall. It receives a force due to the determined electric field.
It advances toward the high pressure side while moving approximately in a circular motion.

However, if this continues, the velocity vector of the secondary electrons will have the above-mentioned dispersion, so the second stage dynode electrode 6
4. There are a considerable number of electrons that reach the insulating layer,
However, regarding this point, Japanese Patent Application Laid-Open No. 16392/1983 discloses the use of Tevarotini as a spacer. A new disadvantage of having to undergo a thermal process is the object of the present invention i! A high-brightness electron beam amplification unit that has a simple structure and is easy to manufacture, as well as an electron beam amplifier and a flat panel display using the same, solves the problems with voltage resistance and productivity of the conventional example mentioned above all at once. The purpose is to provide a device.

Means for Solving the Problems The present invention is aimed at increasing the electron beam amplification factor of an electron beam amplification unit and solving the withstand voltage problem. The electron beam amplification device of the present invention is characterized by being coated with one or more materials, preferably frit glass (PbO). A high-resistance electron beam amplification device characterized in that the electron beam amplification device of the present invention is integrated is also a flat panel display device of the present invention (above). The electron beam amplification unit of the present invention (2) has a thin metal plate as its skeleton and is provided with a material such as fritted glass (PBO), so that the entire inside of the aperture that contributes to electron beam amplification is covered with the material. Although it depends on the incident angle of the incident electron beam, and the entire surface of the inner wall of the aperture contributes to electron emission and a constant electron beam amplification factor can be obtained, this book is constructed by integrating the electron beam amplification unit with the above structure. The electrical resistance of the electron beam amplification device of the invention is 106 to 1
With a high resistance of 0t2Ω, a weak current constantly flows, and there is no discharge phenomenon, the problem of withstand voltage characteristics is solved. C Top This shows the main part configuration of a flat plate image display device according to an embodiment of the present invention.Inner plate vacuum container 1 At least one cathode 2 using thermionic radiation
(Even if the bottom edge of the display screen 6 is arranged horizontally, the entire cathode 2
In front of the cathode 2 is a brifocus lens 3 consisting of 43 grid electrodes, which generates electron beams approximately several times the number of dots in the horizontal direction of the phosphor screen and forms a plurality of electron beams 10 in the x-y plane. , a plurality of electron beams 10
is accelerated and converged to 50 to 200 eV. Modulation of the electron beam can be carried out by modulating a predetermined potential on one of the three grid electrodes.Another modulation method is to provide a new electrode behind the cathode 2 and change this potential. Modulation can also be performed by changing the potential of the cathode.The electron beam 10i is accelerated and focused.The electron beam advances to a predetermined position and is deflected by the deflection lens system 8 to deflect the frame.
direction! In the horizontal direction, it is uniformly deflected in two directions, that is, toward the phosphor screen 7 side.As a specific example of the deflection lens system 8, as shown in FIG. This can be done electrostatically using electrodes that are parallel to each other and are elongated in the horizontal direction and divided at a predetermined pitch in the vertical direction, or alternatively, it can be done by magnetic force. The frame-deflected electron beam 10 (upper) enters a desired aperture provided in the microchannel plate 9.

On one side of the microchannel plate 9,
It is fixed from the inner wall of the vacuum container 1 on the side opposite to the phosphor screen 7 by a suitable conductive or insulating support 12 .

The other side of the microchannel is supported by a conductive material 11 such as a conductive material such as duck or an insulating material 11 such as lead glass provided on the fluorescent screen 7.

Hereinafter, the microchannel plate 9 of the present invention will be explained with reference to FIG. 3. FIG. Even if a large number of approximately circular apertures with a diameter of approximately 50 to 200 μm are provided in the horizontal direction, the number of apertures corresponds to each phosphor on the phosphor screen, and in the vertical direction, the number corresponds to the frame scanning line. Even if a corresponding number of holes are provided, even if a 40-inch high-definition TV has approximately circular apertures with a vertical pitch of 0.6 mm and a horizontal pitch of 0.2 to 0.25 mm, the cross section of the aperture It is desirable that the shape is a straight line.A frit glass 32 is applied inside the aperture at the electron beam input or output end of the electron amplifier.The shape of the cross section of the aperture in the thin metal plate 31 affects the electron beam amplification factor. In most cases, other aperture shapes may be rectangular apertures that are long in the horizontal direction and correspond to several trios of phosphors as shown in Fig. 4 (a). As shown in ), it may be long in the horizontal direction and only its terminal end touches the outer shape.
32 is coated, three to four layers of thin metal plates 31 covered with this frit glass 32 are laminated and integrated L3.
A reduction treatment is performed at 00 to 450° C. in a hydrogen atmosphere to produce lead glass.

Integrated Micro Channel Brake) 94 Table 10
At the same time as it becomes a high resistance material of 6~1Q12Ω, the frit glass 32 on the inner surface of the opening is a material with a high secondary electron emission ratio, so it becomes a multiplier with a high electron beam amplification factor. If there is a risk that the microchannel plate 9 may be deformed due to the difference in thermal expansion coefficient between the metal plate 31 and the frit glass 32, the thin metal plate 31 is made of a 42% Ni, 6% Cr alloy.
If you use NVAR material, you can further increase the electron multiplication factor between the surfaces of the frit glass 32. Example of a material with a high secondary electron emission ratio ζ:;! If a high IE pressure of 1 to 4 kV is applied between both ends 33 and 34 of the electron beam multiplier (Fig. 3) configured as above, for example, about 40 type. on high-definition TV (Dai 1)
A current of about 0 to 1000 pA constantly flows. Although the voltage characteristics are resolved and the power consumption due to this is small in the entire display device, the inner wall ζ of the microchannel plate 9 forms a substantially continuous surface. The angle of incidence of the beam also has the advantage of being amplified without depending on the travel distance within the aperture.

Furthermore, the alignment of the openings provided in the thin metal plate 31 before the application of the frit glass 32, and the subsequent alignment of the frit glass 32
(~Effects of the Invention) The electron beam amplification unit 1 of the present invention has a thin metal plate with a plurality of holes as a skeleton, and a material having a secondary electron multiplication factor of 1 or more, such as frit glass. By applying
It is possible to obtain a high electron beam amplification factor without depending on the incident angle or velocity of the incident electron beam, and the electric power of the electron beam amplification device of the present invention is also Resistance is 10'~1
It has a high resistance of QIIΩ, and when a voltage is applied, a small current always flows, which solves the problem of voltage resistance and makes it possible to realize a good flat panel display device with high brightness and no problems with withstanding voltage4. FIG. 2 shows the cross section of a flat panel display device according to an embodiment of the present invention.
The figure is a cross-sectional view of the microchannel plate in the same example. FIG. 4(a) shows the shape of the openings in the microchannel plate. FIG. 4(b) shows a modified example of the shape of the holes in the microchannel plate. Figure 5 shows the configuration of a flat panel display device in a conventional example.
8. Fluorescence i8. ,, polarizing lens &'9. ．． ．． Mylochannel plate, 31. ,, Metal thin K 32.
,,Frit glass agent's name Patent attorney Shigetaka Awano and one other person Figure 6Cb)

Claims (4)

[Claims] (1) A thin metal plate with approximately the same number of openings as the number of scanning lines of the display device or several times that number in the vertical direction has a secondary electron multiplication factor of 1.
An electron beam amplification unit characterized in that the above-mentioned substance is coated so as to cover substantially the entire surface of the thin metal plate. (2) The electron beam amplification unit according to claim 1, wherein the material having a secondary electron multiplication factor of 1 or more is frit glass. (3) An electron beam amplification device characterized in that a plurality of electron beam amplification units according to claim 1 are stacked and integrated, and a voltage is applied to both ends of the unit so that a leakage current flows. (4) At least one electron source, an electron beam focusing means for focusing the electron beam emitted from the electron source, and a fluorescent display screen made of at least one color of phosphor, in a vacuum container; 4. A flat panel display device, comprising: an electron beam amplification device according to claim 3, and configured such that an electron beam incident from the electron source is amplified by the electron beam amplification device.