JPS6041357B2 - electro-optic display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electro-optical display device including an electrode plate provided on an arbitrary substrate such as glass or plastic in an electrode portion having a variable area.

Currently, electrode plates, which are made by forming a conductive film on a substrate such as glass or plastic, are used not only in electronic engineering fields such as electro-optical elements and heating elements, but also in various fields such as drip-proof and anti-fog glass. It is becoming widely used.

When such an electrode plate is used as an electro-optical display element, or when a decorative effect is intended, it is preferable that the energized display area is variable.

Conventionally, such a requirement has been met by providing a plurality of separate electrode sections on the electrode slope, connecting each of them with wires, and changing the energized points. For example, the dial of a wristwatch or an electronic desk calculator is equipped with a "''-shaped electrode section consisting of seven separate electrode sections, and numbers from 0 to 9 can be displayed by changing the energized points. However, this In this case, the individual electrode sections only turn on and off repeatedly, and there is no change in the display area.Therefore, there is a limit to the changes in display that can be made by changing or combining the energized points of multiple electrode sections. Needless to say, the present invention provides an electrode plate in which the area of each electrode portion changes, thereby enabling more diverse displays.

These objectives are achieved through the combination of variable electrode properties of certain materials and the location of permanent electrodes. That is, the electro-optical display device of the present invention includes an electrode portion partially provided on one surface of a substrate, and a variable electrode film provided on the substrate in contact with the electrode portion and extending to a non-electrode portion. and a counter electrode plate facing the electrode plate are narrowly arranged with an electro-optic material interposed therebetween, the variable electrode film being non-conductive in the highest oxidation state but in the lower oxidation state. It is characterized by being composed of a transition element oxide that exhibits conductivity in an oxidized state and a completely green substance. Hereinafter, the present invention will be explained in more detail with reference to the drawings. 1 to 6 are cross-sectional views conceptually showing the laminated structure of the electrode plate in the present invention.

In FIG. 1, an electrode plate 1 includes a substrate 2, an electrode section 3 partially provided on one surface thereof, and an electrode section 3 provided on the substrate in contact with the electrode section 3 and extending to a non-electrode section. A film-like material (hereinafter referred to as variable electrode film) made of a material whose conductivity changes upon application of a DC voltage (hereinafter referred to as variable electrode material) 4
It consists of Although the substrate 2 can be made of any non-conductive material such as glass, plastic, ceramic, paper, cloth, etc., transparent materials such as glass, plastic etc. can provide particularly attractive display elements.

The substrate may be a flat plate or a curved plate. Electrode part 3
is formed by, for example, pasting, spraying, or vapor deposition a thin film of metal or conductive metal oxide on a substrate. Preferred examples of conductive film materials include Au,
Metals such as Ag and Cu, Sn02, In203, etc., are preferably formed into a transparent electrode film with a thickness of about 0.01 to 1.0 mm, or formed into a film with a thickness of about 0.01 to 10 mm to make it opaque. Use as an electrode film. Further, it is desirable that the redox potential of the electrode film is higher than the redox potential of the variable electrode material. An electrode plate in which a thin film of Sn02 is deposited on a glass substrate or a gold paste is printed and fired on a ceramic substrate to form a film is a preferred combination of a substrate and an electrode in the present invention. The electrode portion is partially provided in a desired pattern on one surface of the substrate. Such patterning is easily achieved by means such as photoetching. The variable electrode material constituting the variable electrode film 4 is a transition element oxide, which is non-conductive in the highest oxidation state but conductive in the lower oxidation state, such as Mo, Cy, V, Ti, Re, Nb,
An oxide of one or more elements selected from Cr, Mn, Fe, Co, Ni, Cu, Pb, etc., preferably an oxide of one or more elements selected from Mo, W and V, and Si○×(
x=1~2), MgF2, Mg0, AI203, &03
, Ba○, Be○, Bi203, Ca○, Ce02, L
i20, S^]2, Ta2〇.

, Zr02, CeF2, etc. The reason why the variable electrode material of the present invention, which is obtained in the coexistence of such a transition element oxide and the above-mentioned insulating material, changes its conductivity upon application of a DC voltage is as follows.
It's not always obvious.

However, it is mainly the transition element oxide that contributes to the change in conductivity, and the presence of the insulating material is thought to be related to stabilization of the charge state when a DC voltage is applied. If this insulating material does not exist, there is a drawback that the dew conductivity change in the present invention is difficult to reach in the direction parallel to the variable electrode film surface, and the desired effect is weakened. There is a preferable state in which the transition element oxide and the insulating material coexist in the variable electrode film 4.

It is a layered distribution rather than a uniform distribution;
According to FIG. 2, the transition element oxide layer 4b is located on the substrate side and in contact with the electrode portion 2, and the insulating material layer 4a is located on the opposite side to the substrate and exposed to the outside. Such a distribution, for example, makes the transition element oxide layer 4b approximately 0.01
After being deposited to a thickness of ~1.0 μm, the insulating material layer 4a is then deposited.
It can be obtained by vapor depositing to a thickness of about 0.005 to 1.0 cm. In this case, the boundary between layers 4a and 4b is not sharp as shown in FIG. 2, but rather has a continuous change in concentration due to the diffusion of both substances. The thickness of the variable electrode film can be increased by repeating the deposition of both materials alternately. However, in either case, it is preferable to ensure that the insulating material is preferentially present in the outermost layer. Furthermore, when the insulating material is more volatile than the transition element oxide, the arrangement substantially as shown in FIG. 2 can also be obtained by simultaneously depositing a mixture of both materials using the same deposition source.

The positional relationship between the electrode portion 3 and the variable electrode film 4 is such that the variable electrode film 4 is provided on the substrate 2 in electrical contact with the electrode portion 3 and extending to the non-electrode portion. , which is quite arbitrary and includes the arrangements shown in FIGS. 3 to 6 in addition to the arrangements shown in FIGS. 1 and 2.

For example, the arrangement shown in FIG. 3 can be obtained by providing the variable electrode film 4 and then forming the electrode section 3 by, for example, vapor deposition. In the cases of FIGS. 3 to 6 as well, it is preferable that the transition element oxide and the insulating material in the variable electrode film are arranged such that the insulating material is preferentially arranged in the outer layer. Note that the first
It is also possible to provide an outermost layer of an insulating material on the electrode plate shown in Figures 6 to 6, which is particularly preferred in the case of AC drive. Further, the layer 4a in FIG. 2 can be replaced with such a full-surface insulating material layer, and in the arrangement shown in FIG. 3, a transition element oxide layer 4b is provided in place of the variable electrode film 4, and then a permanent electrode film 3 is provided. It is also possible to provide such an entire insulating material layer after application. The most suitable method for forming the variable electrode film 4 on the substrate is a vapor deposition method including vacuum heating vapor deposition, sputtering, and ion plating.

As the conditions for these vapor depositions, the conditions known for each of the transition metal oxide or the insulating material can be used as they are. For example, as an example of the former, Moo3 is 2×
10-5Ton by vacuum heating evaporation at 900 to 1300 pm; or by sputtering at 10-1 to 10-Ton; as an example of the latter, Si0 is 2 x 10-5T
On, vacuum heating at 800 to 120,000 tons, or sputtering at 10-1 to 10-3 tons can be easily deposited. The electro-optical display device of the present invention can be obtained by making the electrode plate of the present invention thus formed (hereinafter referred to as a variable electrode plate) facing a counter electrode at a distance.

FIGS. 7 to 10 are cross-sectional views showing the conceptual structure of various examples of the electro-optic display device of the present invention obtained in this way, including the wiring state. Here, explanation will be given mainly taking a twist type liquid crystal display device as an example. In FIG. 7, a variable electrode plate 1 and a counter electrode plate 6, both of which are substantially flat plates, are placed facing each other with their respective electrode surfaces facing inwards and spaced apart so that their alignment processing directions intersect. A medium 7 made of a dielectric or a non-conductor, in this case a nematic liquid crystal having positive dielectric anisotropy, is interposed.

The substrate 2' of the counter electrode plate 5 and the electrode section 3' provided on the entire surface of the substrate 2' are selected from the same material as that of the variable electrode plate 1, and the electrode plates 1 and 5 are transparent. A pair of polarizing plates (not shown) having a plane of polarization parallel to the orientation direction of the adjacent electrode plate is arranged on the outside of the electrode plate, and a light source (not shown) is arranged on the opposite side of the viewing direction. . Such a configuration is very common for twist-type liquid crystal display devices, and provides a display in which the portion where the electrode portions of both electrode plates overlap becomes a dark portion. However, in the example of Figure 7,
The only difference is that a variable electrode plate 1 is used instead of a normal electrode plate (not having a variable electrode film 4). Now, in the apparatus shown in FIG. 7 constructed in this manner, a DC voltage is applied by a DC power source 6 between the electrode portions 3 and 3' of both electrode plates. When the negative electrode is connected to the permanent electrode part 3 of the variable electrode plate 1 as shown in the figure, even if a display corresponding to the permanent electrode part 3 is initially obtained, the variable electrode film 4 also becomes electrically conductive. Finally, a display corresponding to the electrodes 34 can be obtained (since the counter electrode plate 5 is a full-surface electrode, a display corresponding to the electrodes of the variable electrode plate 1 can be obtained). Therefore, a display that is larger than the original one can be obtained. On the other hand, if the polarity of the DC power supply 6 is reversed in the enlarged display state obtained in this way (this can be easily done by using a polarity conversion switch), the variable electrode film 4 gradually changes. It is oxidized and loses its conductivity, and finally the display corresponding to electrode 3,
In other words, there will be 4 stripes on the original display. The above enlargement-reduction display cycle is repeatable. and,
It is easy to understand that the display using such an enlarged/reduced display cycle can be used in combination with the conventional changing of the energized parts of the plurality of separate electrode sections and the display combination. Figure 8 is the 7th
The figure shows an example in which a variable electrode plate 1' is used in place of the counter electrode plate 5, and in this case, two completely different displays are possible. For example, as shown in FIG. 5, the variable electrode plate 1 includes two variable electrode plates consisting of a partial permanent electrode part 3 and a variable electrode film 4 that completely fills the remaining part. The character "GO" is formed by the permanent electrode part 3, and the character "S" is formed by the permanent electrode part 3' on the other electrode plate 1'.
If you form the letters TOP' and connect the wires as shown,
In the electrode plate 1, the entire surface changes into an electrode castle due to the negative unit, and in the electrode plate 1', only the permanent electrode portion 3' functions as an electrode, resulting in the display of "STOP" corresponding to the 3' portion.
Here, if the polarity of the DC power source 6 is reversed, the display of "GO" corresponding to the permanent electrode portion of the electrode plate 1 can be obtained for exactly the same reason. In FIG. 9, in place of the DC power supply 6 in FIG.
As a drive power source, an AC power source 9 biased with a DC power source 6
In this case, the display can be changed gradually compared to the case of the connection shown in FIG.

In FIG. 10, a variable electrode 4 is provided by contacting both of two spaced apart permanent electrode parts 3 in the variable electrode 1, a DC bias voltage is applied between these two permanent electrodes, and an AC voltage is applied between the opposing electrodes. In this case, a display extending from the negative electrode side to the positive electrode side is possible.

In the explanation of FIGS. 7 to 10 above, an example of a twist type liquid crystal display was used.

However, in the electro-optical display device of the present invention, all conventional liquid crystal displays are possible within the scope of its basic configuration. For example, in the above-mentioned twist type liquid crystal display device, a memory type liquid crystal display can be created by adding cholesteric liquid crystal in addition to a nematic liquid crystal having positive dielectric anisotropy as a liquid crystal, and a nematic liquid crystal composition having negative dielectric anisotropy. By using a DS type liquid crystal display (in this case, there is no need to align the electrode plates or use a polarizing plate, the basic configuration is very similar to the electro-optic display device of the present invention), as well as other DAP type, Displays of HAN type, guest host type, etc. are possible, and charge transfer added type liquid crystal can also be used. Furthermore, instead of liquid crystal, a solid thin film such as a PL film that utilizes the electro-optic effect of a dielectric material may be maintained, or only the electrode film portion of the electrode plate of the present invention may be attached to the surface of this thin layer of PLZT. It is also possible to use it with
For example, it is also possible to use organic electrochromic substances such as dipyridium salt solutions in place of liquid crystals;
Electroluminescence (EL) display is possible by using a dielectric material in which phosphor powder such as zinc sulfide is dispersed as the medium 7, and plasma display is possible by filling dilute gas such as argon as the medium.

In either case, the display change in the case of AC drive is based on the 0 applied DC bias voltage. Furthermore, in FIGS. 7 to 10, both the variable electrode plate 1 and the counter electrode 5 are flat plates.

However, the variable electrode plate is a curved plate (e.g. cylinder, hollow sphere)
The counter electrode may be a curved plate or a comb-like electrode. As mentioned above, according to the present invention, a novel variable electrode plate is created by skillfully combining variable electrode characteristics obtained by a combination of a certain transition metal oxide and an insulating material with a normal normal-conducting permanent electrode. provided,
Furthermore, by providing an electro-optic display device including this, it becomes possible to perform electro-optic displays with far more variety than conventional displays.

The present invention will be explained in more detail below with reference to Examples. Example 1 An electrode according to the present invention having a laminated structure conceptually shown in FIG. 2 was obtained by the following procedure.

Etch Nesa glass with a Sn02 electrode film of 0.04# skin thickness on a glass substrate and 3×I with a spacing of 2 fences.
The rectangular electrode membrane 3 of the Q cough was left behind.

A 15 x 10 rectangular, 0.05mm thick Mo
o3 film was formed by vacuum heating evaporation (deposition conditions 2×1
0-5Ton, 100000).

Next, a Si○ film with the same shape and thickness of 0.1 is deposited on the Moo3 film.
0 Buddha (evaporation conditions 2×10-5Ton, 110
00C), the electrode plate shown in FIG. 2 was obtained. The electrode plate 1 obtained in this way and the counter electrode plate 5 made of Nesa glass are combined into one
They were held in parallel with a liquid crystal in between with a distance of 0 degrees apart, and a silk wire was applied as shown in FIG. 7, and a DC voltage of 15 V was applied for 5 minutes.

After applying a DC voltage, the resistance between two points taken one distance apart in a direction perpendicular to the tangent to the electrode part 3 on the variable electrode film 4 on the electrode plate 1 to which a negative voltage was applied was measured and found to be 3000. It was recognized that the material was substantially conductive.

Next, the polarity of the DC power supply 6 was reversed, and a reverse voltage of 15 V was applied for 10 minutes.

Similarly to the above, when we measured the resistance between two points one distance apart on the variable electrode film, it was 5×1.

ohm and was found to be substantially insulated. After repeating the above cycle 20 times, it was confirmed that the above cycle was reversible.

In addition, in the above, the SiO film was provided not only on the MoQ film but also on the entire surface of the electrode plate, and the
Similar results were obtained when driving with a rectangular wave AC voltage of V.

Example 2 Using the same procedure as Example 1, each plan view is shown in Figure 11a.
After forming a pair of electrode plates A and B having patterns as shown in plan views in , b, A and B are subjected to nodal treatment so that their orientation directions are perpendicular to each other to obtain positive dielectric anisotropy. An electro-optical display device was fabricated by sandwiching nematic liquid crystals having the following properties between A and B (from the arrangement shown in the drawing, B was turned over and stacked on A) and placed between mutually orthogonal polarizing plates.

Next, when I applied DC 15V to lead 3a of A at 10 potential and to lead 3a of B at negative potential, a 0 display was obtained in about 1 minute, and by switching the polarity of leads A and B, after 1.5 minutes. The display gradually changed from 0 to 1. Example 3 Similar to Example 1, the results obtained for different combinations of transition element oxides and insulating materials are shown in the table below.

The resistance when insulated is between the boundary between the permanent electrode and the variable electrode, and 1 from the boundary.
The resistance during conduction was measured in the same way between a point on the variable electrode located far away from the ship, and after applying 15 V DC for 10 minutes through the liquid crystal. Transition element Vapor deposition method Insulator Resistance during insulation Resistance during conduction Acid material Thickness (ohm)? Kumoru W03 Electron Beam Mg0 8xlol0
2500.1 m o. 05〃mV2○5 〃
MgF2 3×1011 500Ti02
CeF2 3xlo12 1,oooRe20
7 〃 Ta205 5xlol1 800 Transition Element Vapor Deposition Method Insulator Resistance during Insulation Resistance during Conductivity Thickness of Thickness of Thickness of Thickness of Sulfuric Atom) Junro Nb205
8203 2xlol1 57oCr03
〃 A Buddha 203 5×1012 830Mn
02 〃 Si02 3xloll l
,2ooFe203 〃 Si0 7xloll
130oC.

O 〃 MgF2 6xlo12 1
,5ooNi○ 〃 Si0 8xlol
l l,3ooCuo 〃 Sio 9xlol
l 9ooPb02 〃 MgR2 1
xlo12 1,4oo

[Brief explanation of the drawing]

FIGS. 1 to 6 are cross-sectional views conceptually showing the laminated structure of the electrode plate in the present invention, and FIGS. 7 to 10 conceptually show the structure of the electro-optic display device of the present invention together with the wiring state. The cross-sectional view and FIGS. 11a and 11b are plan views showing an example of a planar pattern provided on a pair of electrode plates A and B. DESCRIPTION OF SYMBOLS 1... Variable electrode plate, 2... Substrate, 3... Electrode part, 4... Variable electrode film, 5... Counter electrode, 6...
...DC power supply. Many Z diagrams Many Z diagrams Many La diagrams Tsutomugo diagrams Many diagrams Many diagrams Many diagrams

Claims (1)

[Claims] 1. An electrode consisting of an electrode portion partially provided on one surface of a substrate and a variable electrode film provided on the substrate in contact with the electrode portion and extending to a non-electrode portion. A device in which a plate and a counter electrode plate facing the electrode plate are narrowly arranged with an electro-optic material interposed therebetween, and the variable electrode film is non-conductive in the highest oxidation state but non-conductive in the lower oxidation state. An electro-optical display device comprising an oxide of a transition element exhibiting conductivity and an insulating material. 2 The variable electrode film is made of Mo, W, V, Ti, Re, N
oxide of one or more elements selected from b, Cr, Mn, Fe, Co, Ni, Cu and Pb, and SiOx (x=1
~2), MgO, MgF_2, MgO, Al_2O_3
, B_2O_3, BaO, BeO, Bi_2O_3, C
aO, CeO_2, Li_2O, SrO_2, Ta_2
and an insulating material selected from O_5, ZrO_2 and CeF_2.