JP2001056747A - Input device and display device with input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve handwriting input ability concerning an input device in a structure sealing a liquid between a pair of mutually confronted substrates. SOLUTION: Concerning the input device having a pair of mutually confronted substrates 8a and 8b, surface electrodes 12a and 12b provided between these substrates and a liquid 21 charged between these substrates 8a and 8b, plural silicon particles 19 are provided at mutual intervals between the substrates 8a and 8b. When input operation is performed by pressing one substrate 8a with an input instrument 3, although the substrate 8a tends to hardly recover into original flat state because of the viscosity of the liquid 21, that substrate 8a can be speedily recovered into initial state by the elastic recovery force of silicon particles so that handwriting input ability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input device provided with a position detecting element such as a thin film resistance layer between a pair of substrates.

[0002]

2. Description of the Related Art In recent years, with the spread of small-sized information electronic devices such as personal digital assistants (PDAs) and palmtop computers, transparent contact input called a touch panel or the like is input to a display device such as a liquid crystal device. A display device with an input function having a structure in which devices are overlapped is known.

As an input device as described above, a liquid is sealed between a pair of substrates each having a transparent electrode as a position detecting element, as disclosed in Japanese Patent Application Laid-Open No. 9-185457. Is known. In this input device, by pressing one of the substrates using an input device such as a pen, the pressed position can be input as position information. The liquid sealed between the substrates in the input device is mainly used to prevent a decrease in brightness of the display device by maintaining a high light transmittance.

[0004]

However, in the above-mentioned conventional input device, since one of the substrates is pressed by using an input device because the liquid sealed between the substrates has viscosity, the substrate is difficult to be moved. There is a problem that handwriting input performance is poor because it is not restored to the initial position.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in a conventional input device, and has an object to improve handwriting input in an input device having a structure in which a liquid is sealed between substrates. .

[0006]

(1) In order to achieve the above object, an input device according to the present invention comprises a pair of substrates facing each other, a position detection element provided between the substrates, And a liquid filled between the substrates, wherein a plurality of elastic members are provided between the pair of substrates.

In the above structure, the "elastic member" is a member having such an elasticity that a substrate which has been locally deformed by being pressed by an input device can be restored to an initial state in a short time. For example, it does not include a member that is hard and has no restorability, such as a dot-shaped protrusion formed by a process based on a photolithography method using a photoresist as a material.

The "position detection element" is an element used for reading a position in an input device. For example, when a resistive touch panel is considered,
A surface electrode provided between a pair of substrates and having a uniform sheet resistance corresponds to the position detecting element.

According to the input device having the above structure, since the elastic member is provided between the pair of substrates, even when the liquid is sealed between the substrates, the pressed substrate can be quickly initialized. It can be restored to a flat state, that is, the handwriting input performance can be improved.

(2) In the input device having the above configuration, the elastic member may be configured to also serve as a spacer for maintaining a space between the pair of substrates. This configuration can be realized, for example, by providing the elastic member at a predetermined density in the plane of the substrate. The method of forming the elastic member is not limited to a specific method. For example, the elastic member can be formed into a predetermined pattern by a process based on a photolithography method, or can be arranged between substrates by dispersion.

The elastic member can be bonded to both of the pair of substrates, can be bonded to only one of the substrates, or can be simply disposed between the two substrates without bonding. . However, for the purpose of improving the resilience of the substrate, it is considered that it is desirable to bond the elastic member to both substrates.

(3) In the input device having the above structure, the elastic member has a Young's modulus of 1 × 10 ⁻⁴ N / m ² to 1 ×.
It is desirable to set to 10 ⁻⁸ N / m ² . This allows
Desirable resilience can be imparted to the substrate.

(4) In the input device having the above-described configuration, the elastic member may be formed of a member exhibiting rubber elasticity, such as, for example, silicon particles, acrylic particles, or urethane particles. This makes it possible to impart desirable restoring properties to the substrate.

(5) The display device with an input device according to the present invention is a display device with an input device, comprising: a display element capable of displaying an image; and an input device provided on the display element. A pair of substrates facing each other, a position detection element provided between the substrates, and a liquid filled between the substrates, and a plurality of elastic members are provided between the pair of substrates. It is characterized by having been done.

According to the display device with the input device of the present invention, since the elastic member is provided between the pair of transparent substrates constituting the input device, even if the liquid is sealed between the substrates, The pressed substrate can be restored to the initial flat state in a short time, that is, the handwriting input to the input device can be improved.

[0016]

FIG. 1 illustrates a case where an embodiment of the input device according to the present invention is mounted on a liquid crystal device as a display device to form a liquid crystal device with an input function. The liquid crystal device with an input function 1 shown here has a liquid crystal panel 2 for displaying a visible image such as a character or a number, and an input device 4 for inputting data by bringing an input device 3 into contact. The input device 4 is provided on the image display side of the liquid crystal panel 2.

A polarizing plate 6a is provided between the liquid crystal panel 2 and the input device 4, a polarizing plate 6b is provided on the opposite surface of the liquid crystal panel 2, and a light reflecting plate is further provided outside the polarizing plate 6b. 7 are provided. This light reflecting plate 7 is a polarizing plate 6
It can also be formed integrally with b. The polarizing axis of the polarizing plate 6a and the polarizing axis of the polarizing plate 6b are opposed to each other at a predetermined angle in order to obtain a polarization transmittance necessary for displaying a visible image.

The input device 4, the polarizing plate 6a, the liquid crystal panel 2,
The components of the polarizing plate 6b and the light reflecting plate 7 that overlap each other are adhered by an adhesive or adhered by an adhesive.

The input device 4 includes a first substrate 8a and a second substrate 8
b are adhered to each other around their periphery by a frame-shaped sealing material 9 formed on the second substrate 8b. The first substrate 8a is made of a first substrate material 11a.
The surface electrode 12a is formed on the inner surface of the liquid crystal panel 2, that is, the surface facing the counterpart substrate, in a range corresponding to the liquid crystal display area of the liquid crystal panel 2 (range indicated by oblique lines in the drawing), and further, the surface electrode 12a is formed. It is manufactured by forming low resistance electrodes 13 at both ends in the Y direction.

The second substrate 8b has planar electrodes 12b formed on the inner surface of the second substrate material 11b in a plane corresponding to the liquid crystal display area of the liquid crystal panel 2 (the area indicated by oblique lines in the figure). It is manufactured by forming low resistance electrodes 14 at both ends in the X direction of the plane electrode 12b. The low resistance electrode 14 is directly led to the terminal portion 16 provided at the end of the second substrate 8b. On the other hand, the low resistance electrode 13 on the first substrate 8a is conductively connected to the auxiliary electrode 18 on the second substrate 8b via the conductive material 17, and further the terminal portion 16 is connected via the auxiliary electrode 18.
It is led to.

On the surface electrode 12b of the second substrate 8b, a plurality of soft silicon particles 19 as an elastic member are provided in a dispersed state with a predetermined plane density. Here, the planar density means that when the first substrate 8a is pressed by the input device 3, the surface electrode 12a on the first substrate 8a bends and deforms at the pressed portion and faces the surface electrode on the second substrate 8b. The plane density is such that it can locally come into contact with the corresponding portion 12b, and the first board 8a can exhibit a restoring force that can restore the original plane state in a short time when the pressing of the input device 3 is released. Is the planar density of

The silicon particles 19 are formed on the first substrate 8a.
And the second substrate 8b may be provided in a state where they are not adhered to those substrates.
It is desirable that the film is in a state where it is not easily moved from side to side because it is adhered to. Such an adhesive state can be realized, for example, by applying a heat-meltable resin around the particles, spraying the particles on the substrate, and then heating the substrate.

The silicon particles 19 mainly apply a restoring force to the first substrate 8a pressed by the input device 3. In the present embodiment, the silicon particles 19 are used as the first particles.
It also functions as a spacer for maintaining a constant interval between the substrate 8a and the second substrate 8b. Then, as shown in FIG. 2, the first substrate 8a and the second substrate 8 maintained at a constant interval.
The liquid 21 is sealed between the liquid 21 and b.

The method of enclosing the liquid 21 is not limited to a specific method. For example, a liquid injection port (not shown) is formed at an appropriate position of the sealing material 9 and the liquid is injected through the liquid injection port by a vacuum injection method. , And then the liquid 21 is sealed by sealing the injection port with a resin or the like.

First substrate material 11a and second substrate material 11
b are both flexible materials such as polycarbonate (P
C), a plastic film made of polyacrylate (PAr), polyethersulfone (PES) or the like. The surface electrodes 12a and 12b are made of a transparent conductive material such as ITO (Indium Tin Oxide), for example, and have a uniform sheet resistance over the entire surface. Further, the low-resistance electrode 13, the low-resistance electrode 14, the auxiliary electrode 18, and the terminal portion 16 are formed, for example, by applying a silver paste.

The refractive index n1 of ITO forming both the surface electrode 12a formed on the inner surface of the first substrate 8a and the surface electrode 12b formed on the inner surface of the second substrate 8b is 1.7.
〜1.9. Now, the first substrate 8a
Considering that there is an air layer between the second substrate 8b and
Since the refractive index n0 of air is 1.0, light is refracted at the interface between each of the surface electrodes 12a and 12b and the air layer, and as a result, the image displayed on the liquid crystal panel 2 is moved outside the first substrate 8a. When viewed from above, it is conceivable that light is generated at the substrate interface due to the difference in the refractive index between the substrate and air, and the display becomes dark.

In this embodiment, the liquid 21 to be filled between the first substrate 8a and the second substrate 8b has a refractive index n
Is selected within the range of 1.0 to 1.7, the difference in the refractive index of ITO forming the surface electrodes 12a and 12b becomes smaller than the difference in the refractive index of ITO in the air layer. When the image displayed on the panel 2 is viewed from the outside of the first substrate 8a, the reflectance at the substrate interface can be reduced, whereby the display looks bright.

In FIG. 1, the liquid crystal panel 2 has a third substrate 22a and a fourth substrate 22b facing each other, and a sealing material 23 formed in a frame shape on one of the substrates.
The liquid crystal panel 2 is formed by bonding the substrates to each other around them.

In FIG. 2, the third substrate 22a has a third electrode 26a formed on the liquid crystal side surface of the third substrate material 24a, that is, a surface facing the fourth substrate 22b, and an overcoat layer 27a formed thereon. And an alignment film 28 thereon.
It is made by forming a. The alignment film 28a is subjected to a rubbing treatment for giving the alignment film an orientation.

The fourth substrate 22b facing the third substrate 22a
Forms a fourth electrode 26b on the liquid crystal side surface of the fourth substrate material 24b, that is, a surface facing the third substrate 22a, forms an overcoat layer 27b thereon, and further forms an alignment film 28b thereon. It is produced by doing. The alignment film 28b is subjected to a rubbing treatment for giving the alignment film an orientation.

The third substrate material 24a constituting the third substrate 22a, which is the substrate close to the input device 4, is formed of a hard material, for example, glass, hard plastic, or the like.
On the other hand, a fourth substrate 22 which is a substrate far from the input device 4
The fourth substrate material 24b constituting b is formed of a flexible material, for example, relatively thin plastic or relatively thin glass.

The third electrode 26a and the fourth electrode 26b
Is made of, for example, 10 by a transparent conductive material such as ITO.
It is formed to a thickness of about 00 Å. Also,
The overcoat layers 27a and 27b are made of, for example, silicon oxide, titanium oxide, or a compound thereof, for example, for 8 hours.
It is formed to a thickness of about 00 Å. Also,
The alignment films 28a and 28b are formed of, for example, a polyimide resin to a thickness of, for example, about 800 angstroms.

As shown in FIG. 1, the third electrode 26a is formed in a so-called stripe shape by arranging a plurality of linear patterns in parallel with each other, while the fourth electrode 26b crosses the third electrode 26a. By arranging a plurality of linear patterns in parallel to each other as described above, they are also formed in a stripe shape. A plurality of points where the electrodes 26a and the electrodes 26b intersect in a dot matrix form pixels for displaying a visible image. And
The area defined by the group of the plurality of pixels is a liquid crystal display area for displaying a visible image such as a character.

The third substrate 22 formed as described above
As shown in FIG. 2, a plurality of spacers 29 are dispersed on one of the liquid crystal side surfaces of the first substrate 22a and the fourth substrate 22b.
Further, a sealing material 23 is provided on the liquid crystal side surface of one of the substrates.
Is provided in a frame shape as shown in FIG. 1 by, for example, printing. As shown in FIG. 2, a conductive material 31 is dispersed inside the seal material 23. A liquid crystal injection port 23a is formed in a part of the sealing material 23 as shown in FIG.

A uniform dimension, for example, a gap of about 5 μm, that is, a so-called cell gap, which is held by the spacer 29, is formed between the two substrates 22a and 22b, and the liquid crystal 32 is injected into the cell gap by a vacuum injection method through the liquid crystal injection port 23a. Is injected, and after the injection is completed, the liquid crystal injection port 23 is formed.
a is sealed with a resin or the like.

In FIG. 1, the third substrate 22a has a substrate overhang portion 22c which extends outside the fourth substrate 22b, and the third electrode 26a on the third substrate 22a is connected to the substrate overhang portion 2c.
The terminal portion pattern 33 extends directly to 2c. The fourth electrode 26b on the fourth substrate 22b is connected to a terminal pattern 33 on the substrate overhang 22c via a conductive material 31 (see FIG. 2) dispersed inside the sealing material 23. The terminal pattern 33 is provided with an external liquid crystal drive circuit (not shown) for electrically driving the liquid crystal panel 2.
This is a wiring pattern for making an electrical connection between the wiring pattern and the wiring pattern.

In practice, a large number of the electrodes 26a and 26b and the terminal pattern 33 extending therefrom are formed at very narrow intervals over the entire surface of each of the substrates 22a and 22b. For the sake of illustration, these electrodes and the like are schematically illustrated at intervals wider than the actual intervals, and further illustration of some of the electrodes and the like is omitted. Further, the electrodes 26a and 26b formed in the region where the liquid crystal is sealed are not limited to being formed in a linear shape as shown in FIG. 1, but may be formed in an appropriate graphic pattern as required. Sometimes.

In the input device 4 shown in FIG.
6 is connected to a control circuit (not shown), and at a certain time, a predetermined voltage is applied between the low-resistance electrodes 14 located at both edges of the second substrate 8b in the X direction. No voltage is applied between the low-resistance electrodes 13 located at both edges of the first substrate 8a in the Y direction, and the first substrate 8a is connected to a voltage measuring element (not shown) in the control circuit. Becomes

Accordingly, a uniform voltage drop occurs in the surface electrode 12b of the second substrate 8b in which the voltage changes linearly at each position in the X direction, and positions having the same position in the X direction are equal to each other. A voltage distribution that becomes a potential is formed. At this time, when one point of the first substrate 8a is pressed by the input device 3 in a region corresponding to the liquid crystal display region of the liquid crystal panel 2, the surface electrodes 12a of the first substrate 8a and the surface electrodes 12b of the second substrate 12b are pressed. Are in contact with each other, via the surface electrode 12a of the first substrate 8a connected to the voltage measuring element,
The voltage of the surface electrode 12b of the second substrate 8b at the position corresponding to the part pressed by the input device 3 can be measured. Since this voltage corresponds to the position in the X direction of the part to be pressed, the control circuit can detect the position in the X direction of the point pressed by the input device 3.

On the other hand, the control circuit connected via the terminal section 16 of the input device 4 causes the low-resistance electrodes 13, 1 located at both edges in the Y direction of the first substrate 8a at another point in time.
3, a voltage is applied to the low-resistance electrodes 14 and 14 located on both edges in the X direction of the second substrate 8b without being applied to the voltage measuring element. Become.

Accordingly, a uniform voltage drop occurs at the surface electrode 12a of the first substrate 8a in accordance with the position in the Y direction,
A voltage distribution in which the voltage changes linearly is formed. The control circuit described above controls the voltage of the surface electrode 12a of the first substrate 8a at the position corresponding to the portion pressed by the input
By detecting through the surface electrode 12b of the substrate 8b, the position in the Y direction can be detected in the same manner as the position in the X direction described above.

Then, by repeating the above control, the above-described control circuit allows the input device 4 to
To detect the position in the X and Y directions of the point being pressed.

Next, in the liquid crystal panel 2, the light reflected by the light reflection plate 7 passes through the liquid crystal layer of the liquid crystal panel 2 and is observed by an external observer. Further, an external control circuit (not shown) for driving liquid crystal is connected to the terminal portion pattern 33 of the liquid crystal panel 2, and the external control circuit controls one of the third electrode 26a and the fourth electrode 26b. A scanning voltage is applied for each row, and a data voltage based on a display image is applied to the other of the electrodes for each pixel. The light reflected by the light reflecting plate 7 and passing through each pixel portion selected by the application of both voltages is modulated by the application of the voltage, whereby the third substrate 22a
A visible image such as a character or a number is displayed outside the box.

In the liquid crystal device with input function 1 of the present embodiment,
An appropriate input screen is displayed on the liquid crystal display area of the liquid crystal panel 2, and when an operator who views the screen desires to input data, a desired portion of the first substrate 8 a of the input device 4 is pressed by the input device 3. I do. Then, the pressed portion is read as, for example, a coordinate position by a control circuit connected to the input device 4, whereby it is recognized which of the plurality of input data displayed on the input screen has been selected by the operator.

In the input device 4 of the present embodiment, as described above, the liquid 21 is sealed between the first substrate 8a and the second substrate 8b, so that the image displayed on the liquid crystal panel 2 can be displayed on the first substrate 8a. The reflectance at the substrate interface when viewed from the outside of 8a can be reduced, whereby the display on the liquid crystal panel 2 looks bright.

When the liquid 21 is sealed between the pair of substrates 8a and 8b, the first substrate 8 locally pressed by the input device 3 due to the viscosity of the liquid 21.
a cannot be easily restored to the original flat state after the pressing is released. However, in the input device 4 of the present embodiment, since the silicon particles 19 as the elastic member for restoring elasticity are provided between the pair of substrates 8a and 8b, even when the liquid 21 is sealed between the substrates. Thus, the pressed first substrate 8a can be restored to the initial flat state in a short time, and as a result, the handwriting input performance can be improved.

(Other Embodiments) The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications may be made within the scope of the invention described in the claims. Can be modified.

For example, instead of silicon particles, another member having rubber elasticity, for example, acrylic particles can be used as the elastic member.

Further, in FIG. 1, the second substrate 8b opposed to the first substrate 8a pressed by the input device 3 is formed by using a flexible material such as plastic or the like. Can be formed using a hard material, such as glass, that is, an inflexible material.

In FIG. 1, the input device 4 is exemplified by a resistive film type input device in which terminal electrodes connected to a low resistance electrode are gathered in one terminal portion 16, but the input device 4 has another structure. Can be used. Further, the present invention can be applied to an input device having a structure using an arbitrary element other than the thin film resistance layer as the position detecting element.

FIG. 1 shows an example in which the input device 4 is used by being mounted on the liquid crystal device 2 as a display device, but the input device 4 is used by being mounted on any device other than the liquid crystal device 2. Alternatively, the input device 4 can be used alone.

[0052]

According to the input device of the present invention, since the elastic member for restoring elasticity is provided between the pair of substrates, even if the liquid is sealed between the substrates, the pressed substrate is pressed. Can be restored to the initial flat state in a short time, and as a result, handwriting input performance can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an input device according to the present invention and an example of a liquid crystal device using the input device.

FIG. 2 is a cross-sectional view illustrating a cross-sectional structure of the input device and the liquid crystal device of FIG.

[Explanation of symbols]

 Reference Signs List 1 liquid crystal device with input function 2 liquid crystal panel 3 input device 4 input device 8a first substrate 8b second substrate 9 sealing material 11a first substrate material 11b second substrate material 12a, 12b surface electrodes (position detection elements) 13,14 low Resistance electrode 16 Terminal 17 Conductive material 18 Auxiliary electrode 19 Silicon particles (elastic member) 21 Liquid

Claims (5)

[Claims] An input device comprising a pair of substrates facing each other, a position detecting element provided between the substrates, and a liquid filled between the substrates, wherein a plurality of substrates are disposed between the pair of substrates. An input device comprising an elastic member. 2. The input device according to claim 1, wherein the elastic member also serves as a spacer for maintaining a space between the pair of substrates. 3. The elastic member according to claim 1, wherein the elastic member has a Young's modulus of 1 × 10 ⁻⁴ N / m ² to 1 × 10 ^4.
An input device which is a ^-8 N / ^{m 2.} 4. The input device according to claim 1, wherein the elastic member is selected from silicon particles, acrylic particles, and urethane particles. 5. A display device with an input device, comprising: a display element capable of displaying an image; and an input device provided on the display element, wherein the input device comprises: a pair of substrates facing each other; And a liquid filled between the substrates, and a plurality of elastic members are provided between the pair of substrates. .