JPH06342332A - Transparent drawing pad - Google Patents

Abstract

PURPOSE:To improve light transmissivity by forming an insulating transparent elastic layer between transparent electrodes. CONSTITUTION:The transparent drawing pad 10 has a couple of transparent substrates 2a and 2b, and the transparent electrodes 3a and 3b are formed on one-side surfaces of the respective transparent substrates 2. Then the couple of transparent substrates 2a and 2b are arranged having the transparent electrodes 3a and 3b opposite each other. The insulating transparent elastic layer 4 is formed between the transparent electrodes 3a and 3b, which are adjusted to a certain interval through the insulating elastic layer 4. The Young's modulus of the insulating transparent elastic layer 4 is preferably 1X10<2>-1X10<6> dyne/cm<2>. Consequently, the transparent drawing pad 10 has the spacer only between the transparent electrodes 3a and 3b and is made superior to a conventional transparent drawing pad which has an air layer present between transparent electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent drawing pad suitable for inputting a handwritten image, and more particularly to a transparent drawing pad excellent in light transmittance.

[0002]

2. Description of the Related Art Conventionally, a transparent drawing pad as shown in FIG. 3 has been known. The transparent drawing pad 1 has transparent substrates 2a and 2b, and transparent electrodes 3a and 3b are formed on one surface of each of the transparent substrates 2a and 2b. Then, the pair of transparent substrates 2a and 2b is formed by the transparent electrode 3
The a and 3b surfaces are arranged so as to face each other. Further, a plurality of dot spacers 5 having substantially the same height are scattered and fixed on at least one of the surfaces of the transparent electrodes 3a, 3b, and the transparent electrodes 3a, 3b are spaced at regular intervals via the dot spacers 5. Has been adjusted. As the transparent substrates 2a and 2b, transparent substrates such as glass plates and plastic films are usually used. As the transparent electrodes 3a and 3b, a transparent conductive film such as ITO is usually used. Further, at least one of the pair of transparent substrates 2a and 2b has flexibility.

In such a transparent drawing pad, when the input side transparent substrate 2a is pressed by the input pen, the pressing portion is bent or distorted, and the transparent portions 2a, 2
The transparent electrodes formed on b contact each other. Therefore, when a character, a figure or the like is drawn on the input side transparent substrate 2a by the input pen, both transparent substrates 2a,
The transparent electrodes 3a and 3b formed on 2b contact each other. And the position coordinates (x, y) along this sliding locus
Is electrically detected, and an image is displayed on an image display device connected to the transparent drawing pad, for example.

When such a transparent drawing pad is provided on the front plate of the image display device, the light transmittance of the transparent drawing pad is high, and the fine drawing displayed on the display screen of the image display device through the transparent drawing pad. It is preferable that characters, thin lines, etc. can be clearly read.

However, in the conventional transparent drawing pad 1 shown in FIG. 3, the air layer 7 exists between the transparent electrodes 3a and 3b, and the refractive index of the transparent electrodes 3a and 3b is generally the refractive index of the air layer 7. And the difference in refractive index between the two is large. For such an air layer 7, for example, the transparent substrate 2a
The reflectance of the light incident on the substrate increases, and as a result, the transmittance of the light passing through the transparent substrate 2b decreases. Therefore, when the conventional transparent drawing pad 1 is attached to the front plate of the image display device, fine characters, fine lines, etc. displayed on the display screen of the image display device may not be clearly read through the transparent drawing pad. There was a problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to overcome the above problems of the prior art, and it is an object of the present invention to provide a transparent drawing pad having a higher light transmittance than the conventional transparent drawing pad.

[0007]

SUMMARY OF THE INVENTION A transparent drawing pad according to the present invention is a transparent drawing pad in which two transparent substrates having transparent electrodes formed on one surface are arranged so that the respective transparent electrodes face each other. An insulating transparent elastic layer is formed between the transparent electrodes.

In the transparent drawing pad according to the present invention, the Young's modulus of the insulating transparent elastic layer is 1 × 10 ² to 1 × 10 ⁶ d.
It is preferably yne / cm ² .

[0009]

DETAILED DESCRIPTION OF THE INVENTION The transparent drawing pad according to the present invention will be specifically described below with reference to the drawings. FIG. 1 shows an example of a transparent drawing pad according to the present invention.

The transparent drawing pad 10 has a pair of transparent substrates 2a and 2b, and transparent electrodes 3a and 3b are formed on one surface of each transparent substrate 2. The pair of transparent substrates 2a and 2b are arranged so that the surfaces of the transparent electrodes 3a and 3b face each other. Transparent electrodes 3a, 3
The insulating transparent elastic layer 4 is formed between the transparent electrodes b, and the transparent electrodes 3a and 3b are adjusted to have a constant interval via the insulating transparent elastic layer 4.

One of the pair of transparent substrates 2a and 2b, for example the transparent substrate 2a, is made of a flexible material such as polyethylene terephthalate film (hereinafter PE).
It is called T film. ) Like a transparent plastic film. A transparent electrode 3a made of a transparent conductive thin film such as an ITO thin film is formed on one surface of the transparent substrate 2a. By drawing an image of characters, figures, etc. on the surface of the transparent substrate 2a with an input pen, the image is displayed on, for example, an image display device (not shown) through the drawing pad.

The thickness of the transparent substrate 2a is preferably 50 μm to 1 including the thickness of the transparent electrode 3a from the viewpoint of pen input.
mm. The transparent substrate 2b is a transparent substrate that may be flexible or rigid, for example, a glass substrate. Further, on one surface of the transparent substrate 2b, a transparent electrode 3b made of a transparent conductive thin film such as an ITO thin film is provided.
Are formed.

In the transparent drawing pad 10 shown in FIG. 1, the insulating transparent elastic layer 4 has a refractive index higher than that of air and is in close contact with the transparent electrodes 3a and 3b without any gap.
That is, a transparent elastic material having a higher refractive index than air is filled between the transparent electrodes 3a and 3b, and the transparent elastic material forms the insulating transparent elastic layer 4. Therefore, the difference in refractive index between the insulating transparent elastic layer 4 and the transparent electrodes 3a, 3b is smaller than the difference in refractive index between air and the transparent electrodes 3a, 3b. Therefore, as compared with the conventional drawing pad having an air layer between the transparent electrodes 3a and 3b, the light reflection inside the transparent drawing pad due to the difference in the refractive index is significantly reduced, whereby the transparent drawing pad has The light transmittance is dramatically increased. As a result, when the transparent drawing pad 10 having the insulating transparent elastic layer 4 is attached on the front plate of the display device, the contrast of the image displayed on the display screen of the display device through the transparent drawing pad 10 is hardly lowered, Moreover, fine characters and fine lines displayed on the display screen can be clearly read.

That is, in order to increase the light transmittance of the transparent drawing pad 10, the insulating transparent elastic layer 4 itself has a high light transmittance, and the transparent electrodes 3a, 3b and the insulating transparent elastic layer 4 are refracted. The difference should be as small as possible.

The insulating transparent elastic layer is a transparent insulating layer having a predetermined film thickness, functions as a spacer between the transparent electrodes 3a and 3b, and maintains the insulating property between the transparent electrodes 3a and 3b. ing.

When the transparent substrate 2a is pressed by the input pen, the pressing portion is deformed and the transparent electrodes 3a, 3
It has a proper insulating property, elasticity, and film thickness such that the b is electrically connected and the deformed pressing portion restores to its original state when the input pen is separated from the transparent substrate 2a.

The insulative transparent elastic layer having the above-mentioned function is, for example, a thermoplastic elastomer such as a silicone elastomer, a styrene thermoplastic elastomer, a urethane thermoplastic elastomer, or an insulating transparent elastic resin such as a flexible epoxy resin. It is made of material.

Further, it is desirable that the insulating transparent elastic layer 4 deformed by pressing the transparent substrate 2a with the input pen restores the original state as quickly as possible when the input pen is separated from the transparent substrate 2a.

To this end, it is preferable to add a viscous resin, an oily substance, a solvent or the like to the insulative transparent elastic layer 4 so as to impart some viscosity. The addition amount of these viscous substances is preferably 10 to 1,000 parts by weight per 100 parts by weight of the insulating transparent elastic substance.

As is apparent from this, in the present invention, the insulating transparent elastic layer includes the insulating transparent viscoelastic layer containing these viscous substances. In the present invention, the insulating transparent elastic material has a Young's modulus of 1 × 10 ² to 1 × when compressed.
10 ⁶ dyne / cm ² , especially 1 × 10 ³ to 1 × 10 ⁶ dyne / cm ²
Is preferred. This Young's modulus is 1 × 10 ² dyne
If it is less than / cm ² , the insulating transparent elastic layer is too soft, and this elastic layer is deformed by an extremely small load to cause conduction between the transparent electrodes 3a and 3b, which is not preferable. Conversely, the Young's modulus is 1 × 10 ⁶ dyne / c
When it exceeds m ² , the input load necessary for conducting the image between the transparent electrodes 3a and 3b to input an image becomes too large, which makes the image input difficult, which is not preferable.

In the present invention, the volume resistivity of the insulating transparent elastic layer is preferably 2 × 10 ⁸ to 1 × 10 ¹⁵ Ω · cm. In the present invention, the thickness of the insulating transparent elastic layer having Young's modulus and volume resistivity as described above is preferably about 0.1 to 5.0 μm.

The transparent drawing pad 10 having the insulating transparent elastic layer 4 as described above can be manufactured, for example, as follows. 1) First, the transparent electrodes 3a and 3b made of a transparent conductive thin film such as an ITO thin film are formed on the surfaces of the transparent substrates 2a and 2b by, for example, a vapor deposition method, a sputtering method, an ion plating method or the like.

2) Next, on the surface of the transparent electrode 3b (or the transparent electrode 3a formed on the transparent substrate 2a) formed on the transparent substrate 2b, the insulating transparent elastic substance as described above or its curing is formed. The precursor or a mixture of these and a viscous substance such as silicone oil is diluted with an organic solvent as necessary, and then applied with a coating means such as a bar coater, a spinner, a roll coater, or dipping, and then heated, etc. The insulating transparent elastic layer 4 is formed by curing by an appropriate means.

3) Then, the transparent electrode 3a portion of the transparent substrate 2a (or the transparent electrode 3b portion of the transparent substrate 2b) is attached onto the insulating transparent elastic layer 4 obtained in the above step 2) to be transparent. The drawing pad 10 is manufactured. On this occasion,
The transparent electrode 3a (or 3b) so that an air layer does not exist between the transparent electrode 3a (or 3b) and the insulating transparent elastic layer 4
b) and the insulating transparent elastic layer 4 are sufficiently adhered.

For this reason, the insulating transparent elastic layer material used when forming the insulating transparent elastic layer 4 preferably has some stickiness, and the surface of the insulating transparent elastic layer 4 is flat. Is preferred.

The transparent drawing pad 10 manufactured as described above includes the transparent electrode 3a, the transparent electrode 3a and the transparent transparent elastic layer 4 interposed therebetween.
3b is adjusted to a predetermined interval, whereby the transparent electrode 3
Insulating property is maintained between a and 3b.

When the input pen 6 presses the surface of the substrate 2a of the transparent drawing pad 10 having such a structure, the insulating transparent elastic layer 4 has elasticity. 2, the substrate 2a and the transparent electrode 3 are shown by the solid line.
a and the insulative transparent elastic layer 4 both deform, and the film thickness of the insulative transparent elastic layer 4 decreases at this deformed portion. The amount of decrease in the film thickness increases as the input load increases. When the thickness of the insulative transparent elastic layer 4 is reduced in this way, the resistance value of the insulative transparent elastic layer 4 is reduced in proportion to the thickness of the insulative transparent elastic layer 4. Then, when the film thickness of the insulating transparent elastic layer 4 becomes smaller than a predetermined value, conduction occurs between the transparent electrodes 3a and 3b. Therefore, when the input pen 6 draws on the surface of the transparent substrate 2a of the transparent drawing pad 10 while applying an input load exceeding a predetermined amount, the image created by drawing is displayed on the image display device through the transparent drawing pad, for example.

Since the insulating transparent elastic layer 4 has elasticity, when the input pen 6 moves from the surface of the transparent substrate 2a, the transparent electrode 3a which has been deformed as shown by the broken line in FIG.
The attached substrate 2a and the insulative transparent elastic layer 4 are restored to their original state, and the transparent electrodes 3a and 3b are adjusted to a predetermined distance again,
Thereby, the transparent electrodes 3a and 3b are insulated from each other.

At this time, when the insulating transparent elastic layer is an insulating transparent viscoelastic layer having elasticity and viscosity at the same time, the insulating transparent viscoelastic layer contracted by pressing with an input pen or the like is When this pressure is released, the original state is restored more quickly than when the elastic layer is used. Therefore, when the insulative transparent elastic layer is an insulative transparent viscoelastic layer, there is a feature that an input trace of the input pen, that is, a writing trace does not remain in the transparent drawing pad forever.

In the present invention, when the insulating transparent elastic layer is formed, fine projections may be provided in advance on the surface of the transparent electrode 3b (or 3a) to which the insulating transparent elastic layer is applied. There is a feature that a flat insulating transparent elastic layer suitable for image input as described above can be easily formed on the surface of the transparent electrode provided with such protrusions.

The method for providing the fine projections on the surface of the transparent electrode in this way is not particularly limited, but the following method may be mentioned, for example. a) Protrusions are formed on the surface of the transparent substrate 2b (or 2a) by an appropriate means, and then a vapor deposition method, a sputtering method or an ion plating method is applied to the surface of the transparent substrate 2b (or 2a) on which the protrusions are formed. The transparent electrode 3b (or 3 made of a transparent conductive thin film such as an ITO thin film)
a) is formed.

B) First, the transparent electrode 3b (or 3a) is formed on the surface of the transparent substrate 2b (or 2a), and then the conductive protrusion is formed on the surface of the transparent electrode 3b (or 3a) by an appropriate means.

As the method for forming the protrusions on the surface of the transparent substrate in the above a), for example, a coating liquid in which fine particles such as silica and a binder are dispersed or dissolved in water and / or an organic solvent is applied to the surface of the transparent substrate. Examples of the method include drying.

As the method for forming the conductive protrusions on the surface of the transparent electrode in the above b), for example, a coating liquid in which conductive fine particles and a binder are dispersed or dissolved in water and / or an organic solvent is used as a substrate with a transparent electrode. Apply to the transparent electrode surface of
A method of drying, or a coating solution containing conductive fine particles and a matrix-forming component such as a partial hydrolyzate of an alkoxysilane is sprayed on the transparent electrode surface of a substrate with a transparent electrode preheated, and then dried. And a method of forming a ring-shaped protrusion on the transparent electrode surface of the substrate with a transparent electrode.

Next, the insulative transparent elastic layer is formed between the transparent electrodes 3a and 3b having the projections formed as described above, for example, according to the methods a) and b). In the drawing pad according to the present invention, since the insulating transparent elastic layer plays the role of a spacer, the spacer used heretofore is not necessarily required, but the transparent electrodes 3a, 3
A spacer and an insulating transparent elastic layer may be used together between b.

In this case, as the spacer, a dot spacer having a spherical shape or another shape is formed on the surface of the transparent electrode 3b (or 3a) according to a conventional method so as to have a predetermined height and a predetermined interval between dots. Obtained by Next, an insulating transparent elastic layer is formed on the surface of the transparent electrode 3b (or 3a) on which the dot spacers are formed by the above method, so that the dot spacer and the insulating transparent elastic layer are used together between the transparent electrodes 3a and 3b. A drawing pad is obtained.

In the drawing pad in which the dot spacer and the insulative transparent elastic layer are used together, the thickness of the insulative transparent elastic layer is made substantially the same as the height of the dot spacer or slightly thicker than the height of the dot spacer. It is desirable to do.

[0038]

As is clear from the above description, in the transparent drawing pad according to the present invention, since the insulating transparent elastic layer is formed between the transparent electrodes of the transparent drawing pad, the spacer is interposed between the transparent electrodes. However, there is a feature that it is superior in light transmittance as compared with the conventional transparent drawing pad in which an air layer exists between the transparent electrodes.

Further, in the transparent drawing pad according to the present invention,
When the input board of the drawing pad is accidentally touched by the hand or finger and the input board is pressed, the minimum load (input load with your hand) that causes conduction between the upper and lower electrodes and images such as characters with the input pen are displayed. Minimum load required for input (required input load)
Since there is a large difference between the input and the input, it is possible to prevent an erroneous input when the input with the pen is made only when the finger or the like touches it by mistake.

Further, in the transparent drawing pad according to the present invention,
Since the insulating transparent elastic layer is formed between the transparent electrodes of the transparent drawing pad, the transparent electrode is not damaged even if the input is repeated many times with the input pen. That is, the transparent drawing pad according to the present invention also has a feature that it is excellent in repeated durability.

Further, when the insulating transparent viscoelastic layer is an insulating transparent viscoelastic layer, when the pressing of the insulating transparent viscoelastic layer by the input pen is released, the pressed portion is promptly restored to the state before pressing. As a result, so-called handwriting traces do not remain in the transparent drawing pad forever, and there is the advantage that the durability is further excellent.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0043]

Examples (1) Preparation of Substrate A 2 k of indium oxide molding containing 5% by weight of tin oxide was prepared.
Using a W electron gun, an oxygen partial pressure of 3 × 10 ⁻⁴ torr and a vapor deposition rate of 3 Å / sec were used to vapor-deposit on a polyethylene terephthalate (PET) film having a thickness of 125 μm preheated to 100 ° C. A base material A having a transparent electrode layer made of an ITO conductive film having a thickness of 0.1 μm formed on one surface was prepared. (2) Preparation of Base Material a Substrate made of a glass substrate with a transparent electrode in the same manner as in (1) above except that a 1.1 mm thick glass substrate was used instead of the PET film and the glass substrate was preheated to 400 ° C. Material B was prepared.

A mixture of 100 parts by weight of a silicone-based elastomer (silicon gel SE1887 manufactured by Toray Dow Corning Silicone Co., Ltd.) and 500 parts by weight of hexane was applied on the surface of the transparent electrode layer of the base material B by a screen printing machine. Then, it is heat-cured at 70 ° C. for 30 minutes, its surface is almost flat, and the average thickness from the glass substrate is 0.4.
A substrate a having an insulating transparent elastic layer of μm formed on its surface was prepared.

The insulating transparent elastic layer of the substrate a thus prepared has a Young's modulus of 4 × 10 ⁴ dyne / cm ² when compressed,
The volume resistivity was 2 × 10 ¹⁴ Ω · cm. (3) Preparation of base material b Organo silica sol (Oscar manufactured by Catalyst Kasei Kogyo Co., Ltd.,
Average particle size: 8,000 angstroms, solvent: isopropanol) after removing the cations and anions in the cation exchange resin and anion exchange resin respectively,
The solvent of this organosilica sol was replaced with hexylene glycol to prepare a silica colloidal dispersion in which silica particles having a concentration of 10% by weight were dispersed in hexylene glycol.

On the other hand, 500 g of tetraethoxysilane (ethyl silicate 40 manufactured by Tama Chemical Industry Co., Ltd., 40% by weight in terms of silica), 1 g of acetic acid, 20 of hexylene glycol.
After mixing 00g and 60g of pure water, this mixed solution is mixed with 5g.
A liquid containing a partial hydrolyzate of tetraethoxysilane (molecular weight 6000 in terms of polystyrene) was prepared by stirring at 0 ° C. for 3 hours.

This liquid was mixed with 0.5 g of the above-prepared silica colloidal dispersion, 800 g of isopropanol and 200 g of butanol to give a solid content of 5.63% by weight, and the proportion of colloidal particles in the total solid content. 0.01
A coating liquid for forming a film having 4% by weight and an ion concentration of 0.3 mmol / liter was prepared.

This coating solution for forming a coating film was applied onto a glass substrate having a thickness of 1.1 mm by a spin coater, the obtained glass substrate with a coating film was dried by heating at 80 ° C., and then 4000 m.
By irradiating the ultraviolet ray of J and further heat-treating at 300 ° C. for 1 hour, a glass substrate with a coating having a plurality of granular projections protruding on the surface of the coating was prepared. The average film thickness of the coating film thus obtained was 1500 Å, and the average distance between the granular projections was 50 μm.

Then, in the state where the coated glass substrate having the protrusions was preheated to 400 ° C., an ITO conductive film was formed on the coated surface of the coated glass substrate by the vapor deposition method in the same manner as in the above (2). A base material C was formed in which a coating film having protrusions and a transparent electrode layer made of an ITO conductive film were sequentially laminated on a glass substrate. The surface of the transparent electrode layer of the obtained base material C was raised in the above-mentioned protrusion shape, and the average height of protrusion from the glass substrate was 1.05 μm.

On the surface of the transparent electrode layer of the base material C, a mixture of 100 parts by weight of a silicone elastomer (Silicone gel SE1886 manufactured by Toray Dow Corning Silicone Co., Ltd.) and 100 parts by weight of toluene was applied by a screen printing machine. Then, the substrate was heat-cured at 70 ° C. for 30 minutes and then at 120 ° C. for 30 minutes, and the surface thereof had a substantially flat surface and an insulating transparent elastic layer having an average thickness of 1.15 μm from the glass substrate was formed on the surface. Material b was created.

The insulating transparent elastic layer of the substrate b thus prepared has a Young's modulus of 5 × 10 ³ dyne / cm ² when compressed,
The volume resistivity was 4 × 10 ¹⁴ Ω · cm. (4) Preparation of Base Material c On the transparent electrode layer surface of the base material C obtained in (3) above, an epoxy resin (Pernox ME-1 manufactured by Nippon Pernox Co., Ltd.) was formed.
13) A mixture of 100 parts by weight, 100 parts by weight of a curing agent (Percure XH-1859-2 manufactured by Nippon Pernox) and 100 parts by weight of cyclohexanone was applied by a screen printing machine and then heat-cured at 120 ° C. for 2 hours, The surface is almost flat and the average thickness from the glass substrate is 1.25.
A substrate c having an insulating transparent elastic layer of μm formed on its surface was prepared.

The insulating transparent elastic layer of the base material c thus prepared has a Young's modulus of 2 × 10 ⁵ dyne / cm ² when compressed,
The volume resistivity was 2 × 10 ¹³ Ω · cm. (5) Preparation of Substrate d Tetraethoxysilane (Ethyl silicate 40 manufactured by Tama Chemical Industry Co., Ltd., 40 wt% in terms of silica) 50 g, acetic acid 1 g, isopropanol 3000 g, and pure water 60 g were mixed, and then this mixed solution was mixed. A liquid containing a partial hydrolyzate of tetraethoxysilane (molecular weight 6000 in terms of polystyrene) was prepared by stirring at 50 ° C. for 3 hours.

This liquid was mixed with 500 g of conductive fine particle-dispersed sol (manufactured by Catalysts & Chemicals Industry Co., Ltd., trade name: Elcom, average particle size: 600 Å, concentration: 10% by weight, solvent: ethanol) to prepare a solid. A coating liquid for forming a conductive film having a content of 1.94% by weight was prepared.

The substrate B obtained in (2) above is preheated to 80 ° C., and then the transparent electrode layer of the substrate B is coated with the above coating solution by a spray method to obtain a coating film. By heating and drying the coated glass substrate at 200 ° C. for 1 hour, a transparent conductive layer in which ring-shaped protrusions having an average ring diameter of 30 μm and an average height of 1,500 angstroms are projected from the coating surface on the transparent electrode layer of the base material B. Base material D having a transparent coating formed thereon
Got

Silicone elastomer (Toray Dow Corning Silicone Silicone Gel SE manufactured by Toray Dow Corning Silicone Co., Ltd.) was formed on the surface of the transparent conductive film of the substrate D thus prepared.
1887) After coating a mixture of 100 parts by weight and 900 parts by weight of hexane with a screen printing machine, 30 at 70 ° C.
After heat-curing for a minute, a substrate d having a substantially flat surface and an insulating transparent elastic layer having an average thickness of 0.42 μm from the glass substrate was formed on the surface.

The insulating transparent elastic layer of the obtained substrate d had a Young's modulus of 4 × 10 ⁴ dyne / cm ² and a volume resistivity of ² when compressed.
It was × 10 ¹⁴ Ω · cm. (6) Preparation of substrate e Acrylic resin (Acrydic A manufactured by Dainippon Ink and Chemicals, Inc.
433) 30 parts by weight, melamine resin (Dainippon Ink and Chemicals Co., Ltd. Super Beckamine L-105) 20 parts by weight, and a mixture of methyl ethyl ketone 960 parts by weight,
On the surface of the base material C preheated to ℃, the liquid flow rate from the height of 1 m above the base material by a nozzle is 20 ml / min, and the pressure is 2 kg.
/ Cm ² sprayed for 1.5 minutes, then the resulting coated substrate is heated at 150 ° C for 1 hour to form a hemispherical spacer made of an acrylic resin on the transparent electrode layer surface Created E.

On the transparent coating surface of the substrate E thus obtained, a silicone-based elastomer (Silicone Gel SE18 manufactured by Toray Dow Corning Silicone Co., Ltd.)
87) A mixture of 100 parts by weight and 400 parts by weight of hexane was applied by a screen printing machine and then heat-cured at 70 ° C. for 30 minutes so that the surface was almost flat and the average thickness from the glass substrate was 2. A base material e having an insulating transparent elastic layer with a thickness of 05 μm formed on its surface was prepared.

The insulating transparent elastic layer of the obtained substrate e had a Young's modulus of 4 × 10 ⁴ dyne / cm ² and a volume resistivity of ² when compressed.
It was × 10 ¹⁴ Ω · cm. (7) Preparation of substrate f Spherical particles made of divinylbenzene resin (Micropearl SP manufactured by Sekisui Chemical Co., Ltd., average particle size: 4.25 μm)
3 parts by weight, acrylic resin (Akridic A-405 manufactured by Dainippon Ink Co., Ltd.) 30 parts by weight, melamine resin (Super Beckamine L-105 manufactured by Dainippon Ink Co., Ltd.) 20
A mixture of 1 part by weight and 960 parts by weight of methyl ethyl ketone was added to the surface of the base material C preheated to 80 ° C. for 1 m on the base material.
After spraying with a nozzle at a pressure of 3 kg from the height of 1 minute,
The obtained coated substrate was heated at 150 ° C. for 1 hour to prepare a substrate F in which hemispherical spacers coated with an acrylic resin were formed on the surface of the transparent electrode layer.

On the surface of the transparent coating film of the base material F thus prepared, in the same manner as in the above (6), the surface is almost flat and the insulating property from the glass substrate is 6.25 μm on average. A base material f having a transparent elastic layer formed on its surface was prepared.

The insulating transparent elastic layer of the obtained substrate f had a Young's modulus of 4 × 10 ⁴ dyne / cm ² and a volume resistivity of ² when compressed.
It was × 10 ¹⁴ Ω · cm. (8) Preparation of base material g Spherical silica particles (manufactured by Catalysts & Chemicals Co., Ltd. Masukyu-SW,
20 parts by weight of conductive particles having an average particle diameter of 6 μm and silver plating having an average thickness of 0.05 μm, acrylic resin (Acridic A-405-5 manufactured by Dainippon Ink and Chemicals, Inc.)
0) 840 parts by weight, melamine resin (Dainippon Ink and Chemicals, Inc.)
A coating solution consisting of a mixture of 245 parts by weight of Super Beckamine J-820-60) manufactured by K.K. and 450 parts by weight of isophorone was prepared.

The coating solution thus obtained was applied to the surface of the transparent electrode layer of the base material B by a screen printer,
By heating at 120 ° C. for 1 hour, a base material G having a plurality of conductive granular projections covered with a transparent coating on the surface of the transparent electrode layer of the base material B was prepared.

The average thickness of the transparent conductive coating is
The portion where the granular protrusions did not protrude was 3 μm, and the average distance between the granular protrusions was 100 μm. On the surface of the transparent coating film of the base material G thus prepared, the insulating transparent elastic layer having a substantially flat surface and an average thickness of 6.6 μm from the glass substrate was formed in the same manner as in the above (6). A base material g having a surface formed thereon was prepared.

The insulating transparent elastic layer of the obtained substrate g had a Young's modulus of 4 × 10 ⁴ dyne / cm ² and a volume resistivity of 5 when compressed.
It was × 10 ¹⁴ Ω · cm. (9) Preparation of base material h Spherical silica particles (manufactured by Catalysts & Chemicals Co., Ltd. Masukyu-SW,
2 parts by weight of conductive particles having an average thickness of 0.05 μm and silver plating having an average thickness of 0.05 μm, 270 parts by weight of silicone elastomer (Silicone gel SE1886A manufactured by Toray Dow Corning Silicone Co., Ltd.) and toluene 970. After thoroughly mixing 1 part by weight, the resulting mixture is mixed with a silicone elastomer (Toray Dow Corning
Silicone gel SE1886B manufactured by Silicone Co., Ltd.) 2
A coating solution was prepared by adding 70 parts by weight and mixing.

The coating solution thus obtained is applied onto the surface of the transparent electrode layer of the base material B and heated at 120 ° C. for 30 minutes to cure the silicone elastomer, whereby the surface is almost flat. A substrate h having an average thickness of 4.1 μm from the glass substrate and having an insulating transparent elastic layer having conductive particles dispersed therein formed on the surface thereof was prepared.

The insulating transparent elastic layer of the obtained substrate h had a Young's modulus of 1 × 10 ⁵ dyne / cm ² and a volume resistivity of 5 when compressed.
It was × 10 ¹⁴ Ω · cm. (10) Preparation of Substrate i On the surface of the transparent electrode layer of the above substrate B, 100 parts by weight of a silicone elastomer (Silicone Gel SE1887 manufactured by Toray Dow Corning Silicone Co., Ltd.) and silicone oil (Toray Dow Corning Silicone Co., Ltd. ) Silicone oil SH200) 50 parts by weight and a mixture of 500 parts by weight of hexane are applied by a screen printing machine and then heat-cured at 70 ° C. for 30 minutes so that the surface is almost flat and the thickness from the glass substrate is large. A base material i having an insulating transparent elastic layer having a viscoelasticity of 0.45 μm on the surface was prepared.

The insulating transparent elastic layer of the base material i thus prepared has a Young's modulus of 5 × 10 ³ dyne / cm ² when compressed,
The volume resistivity was 2 × 10 ¹⁴ Ω · cm. (11) Preparation of Substrate j On the surface of the transparent electrode layer of the above-mentioned substrate C, 100 parts by weight of a silicone elastomer (Silicone Gel SE1886 manufactured by Toray Dow Corning Silicone Co., Ltd.) and silicone oil (Shin-Etsu Chemical Co., Ltd.) Made silicone oil KP
N-3504) A mixed solution of 60 parts by weight and 100 parts by weight of toluene was applied by a screen printing machine and then heat-cured at 70 ° C. for 30 minutes and then at 120 ° C. for 30 minutes to give a substantially flat surface. The average thickness from the glass substrate is 1.
A base material j having an insulating transparent elastic layer having a viscoelasticity of 20 μm formed on its surface was prepared.

The insulating transparent elastic layer of the substrate j thus prepared has a Young's modulus of 8 × 10 ³ dyne / cm ² when compressed,
The volume resistivity was 4 × 10 ¹⁴ Ω · cm. (12) Preparation of Substrate k Silicone elastomer (Toray Dow Corning Silicone Co., Ltd.) is formed on the surface of the transparent conductive film of the above substrate D.
Silicone gel SE1887) 100 parts by weight, silicone oil (Shin-Etsu Chemical Co., Ltd. silicone oil KPN-3504) 100 parts by weight, and a mixture of hexane 900 parts by weight were applied by a screen printer, and then 7
Heat cured at 0 ° C for 30 minutes, the surface is almost flat,
A base material k having an insulating transparent elastic layer having a viscoelasticity having an average thickness of 0.45 μm from a glass substrate formed on the surface was prepared.

The insulating transparent elastic layer of the obtained substrate k had a Young's modulus of 3 × 10 ³ dyne / cm ² and a volume resistivity of ² when compressed.
It was × 10 ¹⁴ Ω · cm.

[0069]

Examples 1 to 11 The transparent electrode layer of the base material A and the insulating transparent elastic layers of the base materials a to k obtained as described above are attached to the base material A and the base material a, respectively. The transparent drawing pads of Examples 1 to 11 were manufactured by stacking layers to k and having a detection circuit.

Regarding the transparent drawing pads of Examples 1 to 11,
The following characteristics were evaluated. (1) Required input load From above the PET film which is the transparent substrate of the transparent drawing pad, a vertical load is applied to each of the PET films with a polyacetal resin presser having a curvature radius R of 1 mm and 2 mm, While gradually increasing the load,
The resistance between the upper and lower transparent electrodes is measured, the load value when this resistance becomes 2 kΩ or less is obtained, and this load value is evaluated as the load value necessary for inputting with the input pen on the screen of the transparent drawing pad. did.

(2) Input load with care By applying a load perpendicular to the PET film, which is a transparent substrate of the transparent drawing pad, with a silicone resin presser having a hardness of 60 and a radius of curvature R of 10 mm. While pressing and gradually increasing the load, measure the resistance between the upper and lower transparent electrodes, find the load value when this resistance becomes 2 kΩ or less, and then use this load value on the screen of the transparent drawing pad. It was evaluated as a load value at which noise is generated in the input due to the touch when the input is performed with the input pen.

(3) Durability While pressing a commercially available ballpoint pen with a load of 300 g on the PET film which is a transparent substrate of the transparent drawing pad, this ballpoint pen was slid back and forth on the PET film to draw the drawing pad. The number of round trips until the linearity became defective was evaluated as the durability.

(4) Input state From above the PET film, which is the transparent substrate of the transparent drawing pad, with a load of 300 g, a radius of curvature R at the tip of the polyacetal presser is 2 mm, and a load perpendicular to the PET film is applied and pressed. Then, observe the state of deviation between the input position and the display position when entering characters and figures, and the presence or absence of input missing parts. Good if there is no deviation between the input position and the display position and there are no input missing parts. It was evaluated.

(5) Total light transmittance Digital haze computer (A-20 manufactured by Suga Test Instruments Co., Ltd.)
08) is used to form a transparent substrate for a transparent drawing pad, PE.
Light was irradiated from the T film side to pass through the transparent drawing pad, and the total light transmittance at this time was measured and calculated.

(6) Handwriting traces The presence or absence of writing marks (linear dents) immediately after the commercially available ballpoint pen was slid back and forth while being pressed with a load of 300 g on the PET film which is the transparent substrate of the transparent drawing pad. It was visually observed.

The results are shown in Table 1.

[0077]

Comparative Example 1 On the surface of the transparent electrode layer of the base material B, an insulating paste (1000 medium manufactured by Jujo Chemicals Co., Ltd.) was printed using a screen printing plate having a hole diameter of 150 μmφ and a pitch of 5 mm, and then 120 ° C. And dried to prepare a base material m having dot spacers formed on the surface of the transparent electrode layer.

On the surface of the transparent electrode layer of the base material m on which the dot spacers are formed, the base material A is placed so that the transparent electrode layer contacts the dot spacers. A transparent drawing pad of Comparative Example 1 including a detection circuit was manufactured.

With respect to the drawing pad of Comparative Example 1 thus obtained, the required input load, manual input load, durability, input state, total light transmittance and handwriting were evaluated in the same manner as the drawing pad of Example 1.

The results are shown in Table 1.

[0081]

Comparative Example 2 The base material B was preheated to 60 ° C.
40 parts by weight of polyester resin (Vylon manufactured by Toyobo Co., Ltd.) and methyl ethyl ketone 9 on the transparent electrode layer surface of
60 parts by weight of a mixed solution consisting of 60 parts by weight from a height of 1 m on the base material through a nozzle at a liquid flow rate of 30 ml / min and a pressure of 2 kg / min.
After spraying at cm ² for 1 minute, the resulting coated substrate is
By heating at a temperature of 0 ° C. for 1 hour, a base material n having a hemispherical spacer made of a polyester resin formed on the surface of the transparent electrode layer was prepared.

On the transparent electrode layer surface of the base material n on which the dot spacers are formed, the base material A is placed so that the transparent electrode layer contacts the dot spacers, and a comparative example equipped with a detection circuit is provided. Two transparent drawing pads were manufactured.

With respect to the drawing pad of Comparative Example 2, the required input load, manual input load, durability, input state, total light transmittance and handwriting were evaluated in the same manner as in Example 1.
The results are shown in Table 1.

[0084]

[Table 1]

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a drawing pad according to the present invention.

FIG. 2 is a drawing for explaining the operation of the drawing pad shown in FIG.

FIG. 3 is a sectional view showing a conventional drawing pad.

[Explanation of symbols]

 10, 20, 30, 1 ... Transparent drawing pad 2a, 2b ... Transparent substrate 3a, 3b ... Transparent electrode 4 ... Insulating transparent elastic layer 5 ... Transparent dot spacer 6 ... Input pen 7 ... Air layer

Claims (2)

[Claims] 1. A transparent drawing pad in which two transparent substrates having transparent electrodes formed on one surface are arranged so that the respective transparent electrodes face each other, wherein an insulating transparent elastic layer is provided between the transparent electrodes. A transparent drawing pad characterized by being formed. 2. The Young's modulus of the insulating transparent elastic layer is 1 × 1.
The transparent drawing pad according to claim 1, which has a density of 0 ² to 1 × 10 ⁶ dyne / cm ² .