JPH02273442A - Lamination type fluorescent display panel - Google Patents

Abstract

PURPOSE:To easily draw out electrons from a cathode through the transmission hole of a control electrode portion and cause them to reach the anode by disposing an electron drawing electrode kept in positive electric potential on the side of the anode of the control electrode portion. CONSTITUTION:An electron drawing electrode 34 kept in positive electric potential is disposed on the side of the anode 14 of a control electrode portion 22 equipped with a control electrode 32, 32' located between a cathode portion 24 and the anode 14 which is located on the side of a pipe light layer 18, and electrons from the cathode portion 24 are easily drawn out through the transmission hole of the electrode portion 22 and are allowed to reach the anode 14. Thus the fluorescent display panel is easily formed without necessity of applying high positive electric potential to the anode nor forming the control electrode into a thin film, and in addition, current modulation is enabled while the control electrode is provided with negative electric potential.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to terminals for displaying figures and characters such as computers, and for displaying multi-digit characters and numbers such as message boards. The present invention relates to improvements in cathode parts for stacked fluorescent display panels.

[Conventional technology]

Recently, a stacked fluorescent display panel has been proposed (Japanese Patent Application No. 1.11,633), which can be driven at low voltage even when the number of pixels increases, and which can be made larger. This fluorescent display panel is made of -11
an anode substrate on which a fluorescent layer is provided via an anode, and a control electrode section and a cathode section that are sequentially laminated on the anode substrate via a spacer substrate having a large number of openings such as through holes or slits. , and a back substrate laminated on top of the cathode portion and having a conductive thin film formed on its inner surface. The laminate of these substrates is coated on the peripheral edge with a sealing material such as Fry-I glass, and then hot-pressed at a temperature of 400 to 450°C to integrate them, and the inside is evacuated to form a fluorescent display panel. or formed.

In this fluorescent display panel, the cathode section is made by integrally forming a cathode conductor on an insulating substrate including a number of frames that also serve as supports to prevent the inside from being crushed. It is constantly heated to 600 to 700°C. - The force control electrode part consists of two control electrodes (scanning electrode and signal electrode) formed in a stripe shape and provided orthogonally to each other, and is arranged close to the cathode part. This control electrode section has mesh-like or through-hole-like openings at the intersections of the electrodes to pass or block electrons emitted from the cathode section, and the potential of each electrode is controlled line-sequentially. The light-emitting state and non-light-emitting state of the fluorescent layer on the anode are controlled by applying voltage from The voltage applied to control electrons in this way varies depending on the shape of the cathode part and the control electrode part, and the positional relationship between the cathode part, control electrode part, and anode, but in order for the electrons to pass, a positive voltage is required. Alternatively, a low negative voltage is applied, a negative voltage is applied to block electrons, and a voltage with an intermediate value between these is applied to display an intermediate gray scale. In this stacked fluorescent display panel, the anode and two controls have a thickness of 0.1 mm, an anode potential of 150 V, and a first control electrode, a second control electrode, and a cathode.
The distance to the anode is 0.2 mm and 0.25 mm, respectively.
．． When the potential of the first control electrode is set to Ov as 6 mm,
It has been found that electrons cannot be extracted unless the potential of the second control electrode is set to +30 V or more with respect to the potential of the cathode section. On the other hand, when the second control electrode is removed to create a three-pole structure, the on-potential is Ov, which is the same as the cathode potential, and the off-potential is -20V.

The reason why the potentials applied to the control electrodes are different is as follows. That is, in order to extract electrons from the cathode through the through holes in the control electrode and direct them to the anode coated with the fluorescent layer, electrons are generated from the anode in the area from the anode to the cathode through the through holes in each control electrode. However, in the case of a stacked fluorescent display panel, unlike conventional fluorescent display panels, the distance between the cathode section and the control electrode section is different from that between the cathode section and the control electrode section. Is it possible to control the electrodes, which are small with respect to the distance between the control electrode section and the anode, using high positive and negative voltages to turn electrons on and off at lower voltages than in conventional fluorescent display panels? When a positive voltage is applied to the control electrode, which is located close to the cathode, electrons emitted from the cathode and not accelerated toward the anode due to the electric field easily flow into the control electrode, making them ineffective for light emission. Since a lit current is generated, it is necessary to drive the control electrode at a negative potential with respect to the potential of the cathode portion or with a positive potential lower than the potential around the control electrode.

[Problem to be solved by the invention]

However, the conventional stacked fluorescent display panel has the following drawbacks. That is, if the control electrode section is formed by overlapping two control electrodes made of thin plates such as 426 alloy,
Since these two control electrodes have different positional relationships with respect to the cathode section, different potentials are applied to the respective control electrodes in order to turn on/off electrons emitted from the cathode section and directed toward the anode. For example, since the diameter of the through holes provided in the first and second control electrodes is 0.4 mm, it is difficult for the positive equipotential line from the anode to enter the through holes provided in the control electrode part. The phenomenon is noticeable at the first control electrode located away from the anode, which causes the potentials applied to the control electrodes to be different.

In the case of the triode structure, the positive equipotential surface from the anode passes through one control electrode with a thickness of 0.1 mm and reaches the vicinity of the cathode, so that the potential of the control electrode or the potential of the cathode is different from that of the control electrode. TeO
Even if the electrons reach the anode by passing through a part of the central part of the hole that has a positive potential compared to the potential of the cathode part, or in the case of a tetrode structure, the equivalent thickness of the control electrode or (the equipotential surface from the anode is 0.25 mm), the positive potential from the anode cannot reach the cathode through the through hole provided in this control electrode. Electrons cannot be extracted from the cathode unless a positive equivalent potential surface is generated from the through hole provided in the first control electrode toward the cathode by applying a high positive potential.

Similarly, when the potential of the cathode part of the second control electrode or the natural potential is set, the potential of the first control electrode is set to 2 to 5.
If v is set to positive, it becomes an on state, but in this case, the grid current flowing to the control electrode becomes very large.

An equipotential surface is formed from the anode to the cathode due to the positive potential applied to the anode, which is higher than the potential at the cathode, or a positive equipotential surface from the anode to the cathode is Since the electron beam sequentially penetrates from the through hole of the second control electrode to the through hole of the first control electrode, in the ON state of the electron beam, which is brought to a negative potential slightly lower than the potential of both control electrodes or the cathode part, The first and second electrodes have an interval corresponding to the thickness of the electrode and the thickness of the insulating film.
Due to the gap between the first control electrode and the first control electrode, a positive equipotential surface higher than the potential of the cathode part is difficult to enter the upper part of the first control electrode. 1st
If the control electrode is at a slightly positive potential with respect to the second control electrode, the equipotential surface can easily enter the through hole of the second control electrode, making it easier to extract electrons. Since the spacing between the cathode and the control electrode is narrow, a current that is ineffective for light emission flows, which is preferable because the hollow film is in the direction of the film thickness and is easily broken in the longitudinal direction of the thin film control electrode, reducing reliability. Due to its low cost, it is not suitable for general display devices that require a large area and large capacity.

Therefore, it is difficult to improve the control electrode in the tetrode structure, and therefore, in order to efficiently allow the positive equipotential surface from the anode to reach the cathode, it is necessary to increase the potential of the anode. However, compared to the triode structure, in which on/off is controlled by a negative potential, in the tetrode structure, it is necessary to apply several times the positive potential to the anode to penetrate the positive equipotential surface into the through hole. In this case, it is necessary to apply a potential of several hundred to several kilovolts to the anode, which increases the cost of the power supply, and has the disadvantage that the reliability of the insulated portion between the anode and the spacer substrate decreases.

An object of the present invention is to avoid the above-mentioned drawbacks, to efficiently extract electrons from the cathode without increasing the potential of the anode, and without having to make the control electrode thinner, by forming it as a normal thin plate. We would like to provide a laminated fluorescent display panel that has sharp edges.

Therefore, in order to avoid such disadvantages, the thickness of the control electrode is adjusted so that the positive equipotential surface from the anode can reach the cathode through the transparent holes in the first and second control electrodes. It is desirable to make it smaller. However, for example, if the control electrode is made from a thin metal plate, the thickness of the control electrode is 0.05 mm in consideration of ease of handling during etching, and the thickness of the frit glass is 0.005 mm in consideration of reliability of the fixed part.
Since it is not possible to do the following, it is not possible to expect to reduce the thickness of the control electrode portion. For this reason, the first
It is also difficult to operate the second control electrode at a potential that is negative with respect to the potential of the cathode portion or below the natural potential.

On the other hand, in order to reduce the thickness of the control electrode, the control electrode is formed of a material such as nickel or aluminum or an alloy thereof with a thickness of 1 to 21 Lm with a thin film insulating layer interposed therebetween, and then the area directly below this thin film is etched. The crystal growth direction of the metal thin film is in the same direction.

(Means for Solving the Problems) In order to solve the problems set forth in item 2, the present invention provides an anode substrate having a fluorescent layer provided through an anode, and a control electrode section provided on the anode substrate. and a cathode section, and the control electrode section includes two control electrodes arranged intersectingly in the X and Y directions, and the on/off operation of the control electrode near the cathode section is based on the potential of the cathode section. In a stacked fluorescent display panel that is driven at a negative potential, the control electrode section further includes an electron extraction electrode that is disposed on the anode side of the two control electrodes and is maintained at a positive potential with respect to these control electrodes. The present invention provides a laminated fluorescent display panel with the following characteristics.

[Effect]

In this way, when an electron extracting electrode maintained at a positive potential is placed on the anode side of the control electrode, a positive equivalent potential surface is created that reaches the cathode through the control electrode's transparent hole, so that the electrons from the cathode are The two control electrodes can be easily pulled out through the perforations to reach the anode.

〔Example〕

Embodiments of the wood panel Ill will be described in detail with reference to the drawings. FIG. 1 shows a fluorescent display panel 10 according to the present invention, and this fluorescent display panel lO is mounted on a transparent insulating substrate 12 such as a glass substrate. An anode substrate 18 having a fluorescent layer 16 provided through an anode 14, a control electrode section 22 provided on this anode substrate 18 via a spacer substrate 20, and a control electrode section 22 provided on this control electrode section 22. It consists of a cathode section 24 and a back substrate 26 provided on the cathode section 24.

In FIG. 1, reference numeral 26a is a conductive thin film provided on the inner surface of the back substrate 26.

A glass substrate is used as the transparent insulating substrate 12 of the anode substrate 18, and the anode 14 is made of I To (I n203) formed on this glass substrate by sputter link method.
: S n 02 ) can be used as a transparent conductor. Further, the fluorescent layer 16 is composed of 1 to 2i made of ZnO:Zn.
It further includes an electron extraction electrode 34 that is kept at a positive potential with respect to the scattering electrodes 32 and 32' having a thickness of Lm. This electron extraction electrode 34, like the control electrode 32, 32',
The control electrode 32 is made of a 426 alloy plate with a thickness of 0.1 mm.
．． A through hole 34a is provided by etching to match the openings 32a, 32'a at the intersection of the holes 32'. The control electrodes 32, 32' and the electron extraction electrodes 34 are integrally fixed to each other by a frit glass 36 formed between them by screen printing, pressure bonding and firing.

The anode substrate 18, the spacer substrate 20, the control electrode section 22, and the cathode section 24 are hermetically fixed together using frit glass, and the inside of the device is heated to 10-6 To
The fluorescent display panel is completed by evacuating to a high vacuum of about RR and performing sealing, ridge and ivy treatments.

Next, describing the operation of the fluorescent display panel of the present invention, the cathode section 24 can be provided with first and second control electrodes 32, 32', an electron extracting electrode 34, and a negative film.

The cathode section 24 consists of a cathode conductor 28 made of a tungsten filament coated with an emissive oxide, which is fixed to the back substrate 26 by a support 30 .

As shown in FIG. 2, the control electrode section 22 has through-hole or mesh-shaped openings 32a, 32"a (32") at the intersection so as to pass through and block electrons emitted from the cathode section 24.
two control electrodes 3 in the x and y directions with a (not shown)
2.32". The control electrode 32.32" is
For example, 0, 1 etched in a stripe pattern.
Made of mm-thick 426 alloy plate, openings 32a, 32'a
For example, it consists of a mesh having a large number of through holes with a diameter of approximately 0.3 mm. In this control electrode section 22, the cathode section 2
The control electrode 32 close to 4 is driven at a negative potential with respect to the potential of the cathode portion 24 in either on/off operation. This control electrode section 22 is arranged on the anode 14 side of the two control electrodes 32, 32', and the intervals between the control electrodes 14 are set to 0.2 mm, 0.255 m'm, 0.31 mm, and 1.0 mm, respectively.
6 mm, the control electrode 32, 32' is made of 426 alloy with a thickness of 0.05 mm, and the electron extraction electrode 34 is made of 426 alloy with a thickness of 0.1 mm.
It was made from 426 alloy with a thickness of mm. This fluorescent display panel was driven by always applying a positive bias potential to the electron extraction electrode 34 and controlling the two control electrodes 32 and 32'' by line sequential driving. In this case, the first control electrode 32 was scanned. electrode, and the second control electrode 32' was used as a signal electrode.
The voltage applied between the control electrode 32, the second control electrode 32', the electron extraction electrode 34, and the anode I4 can be changed by changing the potential of the electron extraction electrode 34, or by changing the potential of the cathode part 24. 0■, respectively, and 0 when Ov.
Anode current values of 5 mA/mm2 were obtained for the intersection pixels.

On the other hand, when the scanning electrode is on (0V potential) and the signal electrode is off (-20V potential), the anode current is O in the pixel on the scanning electrode, and the scanning electrode is off (-2ov potential).
Even if the current was applied to the pixel (potential), the anode current did not flow and the pixel did not emit light. The electron extraction electrode 3 to which a positive potential is applied in this way
It is clear that the effect of No. 4 is significant.

When the potential of the first control electrode 32 is maintained at OV and a negative potential is modulated to 20V and 10V and applied to the second control electrode 32', the anode current is linearly 0°2mA and 0.1mA. The luminance of the light emitted varies, and the luminance decreases monotonically. Therefore, it can be seen that by controlling the voltage with a relatively large width, it is possible to obtain a large number of gradations.

In the prior art, it was difficult to take out the lead terminals from the center of the envelope from the thin control electrode 32. When the extraction electrode 34 is used,
Since the control electrode 32.32° can be integrated with the electron extraction electrode 34 and taken out, the lead terminal can be easily extracted.

In addition, an electron extraction electrode that is kept at a positive potential is arranged on the positive anode side on the back side of the electron extraction electrode 34, so that electrons from the cathode can be easily extracted through the through holes of the two control electrodes and reach the anode. Therefore, the control electrode can be easily formed because there is no need to apply a high positive potential to the anode and there is no need to make the control electrode thin. There are practical benefits to being able to modulate the current.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a fluorescent display panel according to the present invention, FIG. 2 is an exploded perspective view of a control electrode section used in the present invention, and FIG. 3 is an enlarged sectional view showing the operation of the control electrode section. 10-1111 fluorescent display panel, 12 transparent insulating substrate, 14----1 anode, 18 fluorescent layer, 18
-1111 anode substrate, 2 1-1111 control electrode section, 24--1 cathode section, 32.3
2'-1111 control electrodes, 34 potentials are always exposed or the electrons extracted from the first and second control electrodes 32.32' are sufficiently accelerated as they pass through the apertures 32a, 32'a. Therefore, there is no need to provide an electrode for applying a negative potential to the back surface. FIG. 3 shows the electron extraction state of the electron extraction electrode 34. When a positive potential is applied to the electron extraction electrode 34 and the potential of the second control electrode 32' is Ov, the first
When the potential is set to negative as shown in the control electrode 32 shown in FIG. The reason why electrons can be easily extracted through the openings of the control electrodes 32 and 32' is that the potential of the electron extraction electrodes creates a positive equipotential surface that reaches the cathode through the control electrode's transparent holes. . (Effect of the invention)

Claims (1)

[Claims] It consists of an anode substrate having a fluorescent layer provided through an anode, a control electrode part and a cathode part provided on the anode substrate, and the control electrode part is arranged intersectingly in the X and Y directions. In a stacked fluorescent display panel including two control electrodes, the control electrode near the cathode section is driven at a negative potential with respect to the potential of the cathode section when turning on/off, the control electrode section is connected to the two control electrodes. 1. A stacked fluorescent display panel, further comprising an electron extraction electrode disposed on the anode side of the control electrode and kept at a positive potential with respect to the control electrode.