JP3041991B2 - Image display device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device in which a pixel is selected by driving an electro-optic material layer using plasma, and more particularly to a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, as a means for increasing the resolution and contrast of a liquid crystal display, a method of providing an active element such as a transistor for each display pixel and driving it (a so-called active matrix addressing method) is known. Generally done. However, in this case,
Since it is necessary to provide a large number of semiconductor elements such as thin film transistors, there is a concern about the yield problem, especially when the area is increased, and there is a serious problem that the cost is increased.

In order to solve this problem, Buzak et al. In Japanese Patent Application Laid-Open No. 1-217396 propose a method in which a discharge plasma is used as an active element instead of a semiconductor element such as a MOS transistor or a thin film transistor. Hereinafter, the configuration of an image display device that drives liquid crystal using discharge plasma will be briefly described.

This image display device is called a plasma-addressed liquid crystal display device (PALC).
As shown in FIG. 5, a liquid crystal layer 101 which is an electro-optical material layer,
The plasma chamber 102 is disposed adjacent to a thin dielectric sheet 103 made of glass or the like.
The plasma chamber 102 is formed by forming a plurality of grooves 105 parallel to each other in a glass substrate 104, in which an ionizable gas is sealed.
Each groove 105 has a pair of electrodes 10 parallel to each other.
6, 107 are provided, and these electrodes 106, 10
Reference numeral 7 functions as an anode and a cathode for ionizing gas in the plasma chamber 102 to generate discharge plasma. On the other hand, the liquid crystal layer 101 is provided on the dielectric sheet 10.
3 and the transparent substrate 108, and a transparent electrode 109 is provided on the surface of the transparent substrate 108 on the liquid crystal layer 101 side.
Are formed. The transparent electrode 109 is provided in the groove 10
5, and the intersection of the transparent electrode 109 and the plasma chamber 102 corresponds to each pixel.

In the above-described image display apparatus, the plasma chamber 102 in which plasma discharge is performed is sequentially switched and scanned, and a signal voltage is applied to the transparent electrode 109 on the liquid crystal layer 101 side in synchronization with the scanning. Is held in each pixel, and the liquid crystal layer 101 is driven. Therefore, each groove 105, that is, each plasma chamber 102 corresponds to one scanning line, and the discharge region is divided for each scanning unit.

[0006]

By the way, it is considered that an image display device using discharge plasma can be easily made larger in area than a device using a semiconductor element as described above. Various problems remain. For example, the protruding ridge portion (that is, the partition wall 110) of the glass substrate separating each plasma chamber 102 is an ineffective portion of an image. However, since the wall surface of the groove 105 is inclined or curved, the direction of transmitted light and Disturbance occurs in the polarization state, which leaks out of this portion and causes deterioration in image quality. In addition, when considering the production of the PALC, the following inconvenience occurs because the glass must be processed by the etching method. That is, although the glass itself is easily dissolved by the hydrogen fluoride acid, there is no problem in the processing itself, but since the adhesion between the photoresist and the glass is poor, the resist peels off before the groove is formed during the processing. There is a possibility that this will occur. Therefore, particularly when a fine pattern or a deep groove has to be formed, it is very difficult to form the groove.

Therefore, the present invention has been proposed to solve the problems of the prior art, and has no extra transmitted light or the like in an ineffective portion, and is capable of obtaining a high-quality image. It is an object to provide a display device. Another object of the present invention is to provide a manufacturing method which can ensure the adhesion between the photoresist and the glass and does not cause inconvenience due to peeling of the resist.

[0008]

In order to achieve the above-mentioned object, an image display device according to the present invention comprises a first substrate having a plurality of first electrodes substantially parallel to each other on one main surface; A plurality of second electrodes substantially orthogonal to the first electrode and substantially parallel to each other
A second substrate having electrodes, wherein the first substrate and the second substrate are arranged substantially parallel to each other such that the first electrode and the second electrode face each other, and a first substrate of the first substrate is provided. The electro-optic material layer is interposed so as to be in contact with the electrode, and a dielectric film is disposed on the second substrate side of the electro-optic material layer, and the space between the dielectric film and the second substrate is glass. A metal film containing Cr is provided between the partition wall dividing the discharge region and the dielectric film, the discharge region being formed by dividing the projecting portion of the second substrate using the ridge portion as a partition and filling an ionizable gas. Is provided.

Further, the manufacturing method of the present invention includes a first substrate having a plurality of first electrodes substantially parallel to each other on one main surface;
A second substrate having a plurality of second electrodes substantially orthogonal to the first electrode and substantially parallel to each other on one main surface, wherein the first substrate and the second substrate are the first electrode and the second substrate; Electrodes are arranged substantially parallel to each other so as to face each other, an electro-optic material layer is inserted so as to be in contact with the first electrode of the first substrate, and an electro-optic material layer is provided on the second substrate side of the electro-optic material layer. A dielectric film is disposed, and a space between the dielectric film and the second substrate is divided by using a convex portion of the second substrate made of glass as a partition, and ionizable gas is sealed therein to form a discharge region. In the method for manufacturing an image display device, the second
Forming a Cr-containing metal film and a photoresist layer on the substrate, and patterning the metal film by photolithography, and etching the second substrate using the photoresist layer on the patterned metal film as a mask And
Forming a partition, and removing the photoresist layer, and laminating an electro-optical material layer via a dielectric film on the metal film remaining on the partition, is there.

[0010]

In the image display device according to the present invention, a metal film containing Cr is formed on the partition wall which divides the discharge region for each scanning unit. This metal film blocks light and functions as a so-called black stripe. Therefore, no extra light leaks out of the partition wall portion, which is an ineffective portion, and the influence on the image is eliminated. In addition, the metal film plays a role in enhancing the adhesion between the glass substrate and the photoresist during the manufacturing process, and fine patterns and deep grooves are formed by etching without causing resist peeling.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below in detail with reference to the drawings. In the image display device of the present embodiment, as shown in FIG. 1, a flat first substrate 1 on which strip electrodes 3 are formed, and a plurality of parallel grooves 4 orthogonal to the strip electrodes 3 are formed. Between the groove 4 and the second substrate 2 having the discharge electrode 5 formed therein,
A liquid crystal layer 6 which is an electro-optical material layer is interposed, and a space between the liquid crystal layer 6 and the second substrate 2, that is, the groove 4 is formed.
The inside becomes a discharge region. These substrates 1 and 2
Is formed of a non-conductive and optically transparent material here, but in consideration of a transmissive display device,
In the case of a direct-view or reflective display device, any one of the substrates may be transparent.

On the first substrate 1, a strip-shaped electrode 3 is formed on one main surface, and a liquid crystal layer 6 made of a nematic liquid crystal or the like is arranged in contact with the electrode 3. The liquid crystal layer 6 is sandwiched between the first substrate 1 and a dielectric film 7 made of glass, mica, plastic, or the like. The first substrate 1, the liquid crystal layer 6, and the dielectric film 7 A so-called liquid crystal cell is configured.
Note that the dielectric film 7 functions as an insulation blocking layer between the liquid crystal layer 6 and the discharge region. Without the dielectric film 7, the liquid crystal material flows into the discharge region (groove 4) or the discharge region does not. The liquid in the liquid crystal material may be contaminated by the gas inside.

On the other hand, a discharge electrode 5 is also formed on the second substrate 2 as a strip-shaped electrode and is attached to the dielectric film 7, and a space between the second substrate 2 and the dielectric film 7 is formed. That is, the space in each groove 4 is a discharge region where discharge plasma is generated. This discharge region is formed by the groove 4
The chambers are partitioned by partition walls 8 formed therebetween, and are formed as independent plasma chambers P ₁ , P ₂ , P _3, ... _Pn . Here, a metal film 9 containing Cr is formed on the upper surface of each partition 8 so as to have the same width as the partition 8, and serves as a black stripe that blocks excess light. This metal film 9 is made of Cr or Cr-Au.
It is made of an alloy or the like, and has a thickness of 1000-1 μm.

The above plasma chambers P ₁ , P ₂ , P ₃ ... P
_{In n} , an ionizable gas is sealed, and plasma is generated by electric discharge. As the ionizable gas, helium, neon, argon, or a mixed gas thereof is used. Also,
The discharge electrodes 5 are formed in a pair in the groove 4 in parallel with each other. Discharge between these electrodes generates discharge plasma in the groove 4. Therefore, each of the plasma chambers P ₁ , P ₂ , P ₃ ... _Pn corresponds to each scanning line.

The schematic configuration of the image display device of the present embodiment has been described above. Each of the substrates 1 and 2 is provided with electrodes for driving the liquid crystal layer 6. Therefore, these electrode configurations will be described next.

First, a plurality of strip-shaped electrodes 3 having a predetermined width are formed on a main surface of the first substrate 1 facing the second substrate 2. These strip electrodes 3 are formed of a transparent conductive material such as indium tin oxide (ITO) and are optically transparent. The strip electrodes 3 are arranged in parallel with each other, for example, arranged vertically to the screen. On the other hand, the groove 4 of the second substrate 2
The discharge electrode 5 is also formed thereon. These discharge electrodes 5 are also parallel linear electrodes, but are arranged in a direction orthogonal to the strip electrodes 3 formed on the first substrate 1. That is, these discharge electrodes 5 are arranged horizontally on the screen. In addition, these discharge electrodes 5
Are the anode electrodes A ₁ , A ₂ , A ₃ ... _{An 1} , _An
A cathode electrode K _1, consists _{K 2, K 3 ··· K n} -1, K n, these are configured discharge electrode in pairs, each plasma chamber _{P 1, P 2, P 3} · .. Are arranged in P _n respectively.

FIG. 2 schematically shows the arrangement of the strip electrodes 3 formed on the first substrate 1 and the discharge electrodes 5 formed on the second substrate. Here, a first signal applying means composed of a data driver circuit 10 and an output amplifier 11 is connected to the strip electrode 3 of the first substrate 1.
Is supplied as a liquid crystal drive signal. On the other hand, the discharge electrode 5 on the second substrate 2
Of the cathode electrodes K ₁ , K ₂ , K ₃ ...
The K _n-1, K n, the second signal applying means comprising a data strobe circuit 12 from the output amplifier 13 is connected, a pulse voltage output from the output amplifier 13 is supplied as a data strobe signal You. In each anode _{A 1, A 2, A 3} ··· A n-1, A n, common reference voltage (ground voltage) is applied. Therefore, the connection structure of the discharge electrodes 5 formed on the second substrate 2 is as shown in FIG. Further, in order to form an image over the entire display surface, a scanning control circuit 14 is connected to the data driver circuit 10 and the data strobe circuit 12 to form an image.
Is provided. The scan control circuit 14 adjusts the functions of the data driver circuit 10 and the data strobe circuit 12, and sequentially addresses all the pixel columns of the liquid crystal layer 6 from row to row.

In the image display device having the above-described configuration, the liquid crystal layer 6 functions as a sampling capacitor for an analog voltage applied to the strip electrode 3 formed on the first substrate 1, and each of the plasma chambers P ₁ , P _2, P ₃ ··· P _n
An image is displayed by the discharge plasma generated in the inside functioning as a sampling switch. FIG. 4 shows a model for explaining this image display operation. In FIG. 4, the liquid crystal layer 6 corresponding to each pixel can be regarded as a capacitor model 15. That is, the capacitor model 15 includes the strip electrode 3 and each of the plasma chambers P ₁ ,
Represents the P _2, P ₃ capacitive liquid crystal cell · · · P _n are formed on the overlapping portion.

Now, it is assumed that an analog voltage is applied to each strip electrode 3 from the data driver circuit 10. Here, when the data strobe signal (pulse voltage) is not applied to the cathode electrode K ₁ of the second substrate 2, that is, in the off state, the anode electrode A ₁ and the cathode electrode K _1
No discharge occurs at ₁ and the gas in the plasma chamber P1 is not ionized. Therefore, the plasma
The switch S ₁ (electrical connection between the strip electrode 3 and the anode electrode A ₁ ) is also turned off, and no matter what analog voltage is applied to the strip electrode 3, each capacitor model 1
There is no change in the potential difference applied to 5.

On the other hand, if the data strobe signal is applied to the cathode electrode K ₂ of the second substrate 2, that is, if the data strobe signal is in the on state, the gas is discharged by the discharge between the anode electrode A ₂ and the cathode electrode K _2. is ionized, the ionization region (discharge plasma) is generated in the plasma chamber P _2.
Then, the strip-shaped electrode 3 and the anode electrode A ₂ are electrically connected by a so-called plasma switching operation.
_This is equivalent to the state where ₂ is turned on. As a result, the column cathode K ₂ is strobed capacitor
The analog voltage supplied to the strip electrode 3 is stored in the model 15. After the strobe to the cathode electrode K ₂ is completed discharge plasma is lost even during (during field period of at least the image) until the next strobe is carried out each analog voltage to the capacitor model 15 Store In this state, the analog voltage applied to the strip electrode 3 is not affected by a subsequent change.

Therefore, the cathode electrodes K ₁ , K ₂ , K
₃ · · · K _n-1, sequentially addressing K _n is applied to the data strobe signal, the plasma chamber _{P 1, P 2, P 3} ·
.. By simultaneously generating a discharge plasma in _Pn and simultaneously applying a liquid crystal drive signal as an analog voltage to each belt-shaped electrode 3 in synchronism therewith, the plasma switch becomes an active element in the same manner as a semiconductor element such as a thin film transistor. And the liquid crystal layer 6 is driven in the same manner as in the active matrix addressing system.

Next, a method of manufacturing the image display device having the above-described configuration will be described, particularly focusing on a step of forming a groove in a glass substrate. First, a glass substrate 21 corresponding to the second substrate 2
Then, as shown in FIG. 5, a Cr film 22 is formed on the entire surface by a technique such as vapor deposition or sputtering. Here, a soda glass substrate having a thickness of 1.6 mm was used as the glass substrate 21. The thickness of the Cr film 22 is 200
0 °.

Next, a photoresist layer 23 is applied and formed on the Cr film 22, and as shown in FIG. 6, light of a predetermined wavelength is irradiated through a photomask 24 having an opening corresponding to a partition wall, thereby exposing the light. I do. The photoresist layer 23
May have a thickness of about several μm, but it is 2 μm here. The photoresist used was a cyclized rubber-based negative resist (OMR-83, manufactured by Tokyo Ohka Co., Ltd.).

After developing the photoresist layer 23, FIG.
As shown in (1), the Cr film 22 is etched with a selective etchant of Cr such as cerium nitrate.

Next, the photoresist layer 2 is heated by heat.
After fixing 3 on the Cr film 22, the glass substrate 21 is etched with a hydrofluoric acid to form a groove 24, as shown in FIG. The etching condition of the glass substrate 21 is arbitrary, but here, the glass substrate 21 was etched using hydrofluoric acid of 25% for about 30 minutes. Further, the depth of the formed groove 24 is 150 μm, the interval between the grooves 24 is 50 μm,
The pitch is 300 μm.

Finally, the photoresist layer 23 is peeled off and a discharge electrode is formed in the groove 24. Then, an electro-optic material layer is laminated on the Cr film 22 via a dielectric film, and the image display device is manufactured. Complete.

Although specific embodiments to which the present invention is applied have been described above, the present invention is not limited to these embodiments, and the material, shape, dimensions, and the like are arbitrary.

[0028]

As is clear from the above description, in the image display device of the present invention, since the metal film is formed on the partition walls, this metal film plays the role of a black stripe and provides high quality. Image display is possible. Further, according to the production method of the present invention, the adhesion between the photoresist and the glass can be improved by the metal film containing Cr, and the resist can be prevented from peeling off during etching with hydrofluoric acid. Therefore, a fine groove or a deep groove having a depth of 50 μm or more can be easily formed, and the productivity of an image display device having a plasma chamber can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of an image display device to which the present invention is applied.

FIG. 2 is a schematic diagram showing an electrode configuration for driving a liquid crystal layer.

FIG. 3 is a schematic diagram showing an arrangement and connection states of discharge electrodes.

FIG. 4 is an equivalent circuit diagram for explaining an image display operation.

FIG. 5 is a schematic cross-sectional view of a main part showing a step of forming a Cr film.

FIG. 6 is a schematic cross-sectional view of a principal part showing a step of exposing a photoresist layer.

FIG. 7 is a schematic cross-sectional view of a main part showing a step of etching a Cr film.

FIG. 8 is a schematic cross-sectional view of a main part showing a step of etching a glass substrate.

FIG. 9 is a schematic cross-sectional view of a main part showing a step of removing and removing a photoresist layer.

FIG. 10 is a schematic sectional view showing an example of a conventional image display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st board | substrate 2 ... 2nd board | substrate 3 ... Strip electrode 5 ... Discharge electrode 6 ... Liquid crystal layer (electro-optic material layer) 8 ... Partition 9 ... Metal film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1333 G02F 1/1335 G09F 9/30 G09G 5/00 G09G 3/28

Claims (2)

(57) [Claims] 1. A first substrate having a plurality of first electrodes substantially parallel to each other on one main surface, and a plurality of second electrodes substantially orthogonal to the first electrodes and substantially parallel to each other on one main surface. The second with
The first substrate and the second substrate are the first substrate.
An electrode and a second electrode are disposed substantially in parallel with each other so as to face each other, and the electro-optical material is contacted with the first electrode of the first substrate.
A second layer of the electro-optic material layer
A dielectric film is disposed on the substrate side, and the dielectric film and the second substrate
The space between the plates separates the ridges of the second substrate made of glass.
Separated as a wall and filled with ionizable gas and discharged
Region between the partition wall dividing the discharge region and the dielectric film.
An image display device comprising a metal film containing r. 2. A first substrate having a plurality of first electrodes substantially parallel to each other on one main surface, and a plurality of second electrodes substantially orthogonal to the first electrodes and substantially parallel to each other on one main surface. The second with
The first substrate and the second substrate are the first substrate.
An electrode and a second electrode are disposed substantially parallel to each other so as to be opposed to each other, and are electrically connected to the first electrode of the first substrate.
An optical material layer is interposed and the electro-optical material layer
A dielectric film is disposed on the second substrate side of the dielectric film.
The space between the second substrates is a projection of the second substrate made of glass.
The strip is divided into partitions and ionizable gas is sealed.
In the method of manufacturing an image display device which is
There are, a metal film and a photoresist layer containing Cr on the second substrate made of glass was deposited, masked and a step of patterning the metal film by photolithography, the photoresist layer on the patterned metal film Etching the second substrate to form a partition
The photoresist layer is removed and the metal film remaining on the partition walls
And a step of laminating an electro-optic material layer via a dielectric film .