JP2005099994A - Touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel which can surely seal an aperture of a sealing agent and prevent generation of interference pattern, while of which pressure in data input is light, and which is excellent in operability, reliability and moisture resistance. <P>SOLUTION: In the touch panel which is made up by opposite placement of upper and lower substrates in which a pair of transparent electrodes are arranged with the transparent electrodes inside via the sealing agent arranged along the circumference of the substrates, and sealing of the apertures set up at the sealing agent with a sealing member, the sealing agent 16 has a plurality of apertures 16a and 16b; apertures 16a and 16b are formed in each of the sealing agents 16 which are arranged along with two sides of facing substrates; and sealing members 17a and 17b which seal the apertures 16a and 16b consist of an adhesive which is a resin material of the same line as the sealing agent 16 and is hardened at normal temperature. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a computer, various terminals, vending machines, ATMs, etc., which are arranged on a screen such as a liquid crystal display or a cathode ray tube, and a user displays an information display screen with a finger, a pen, etc. It is related with the touch panel in which data is input by pressing directly on the screen.

  The touch panel in the prior art has a flexible upper substrate provided with transparent electrodes and a lower substrate provided with transparent electrodes interposed via a sealing agent so that the transparent electrodes face each other with a predetermined space therebetween. Has been placed. When the upper part of the upper substrate is pressed with an input pen or a finger in this touch panel, the upper substrate is bent and the transparent electrode of the upper substrate comes into contact with the transparent electrode of the lower substrate at the pressing point. Then, the coordinates of the contact point are detected by measuring the electric resistance, and the input information is read.

In such a touch panel, in order to smooth the return (bounce) of the upper substrate after data input and prevent the occurrence of interference fringes, an opening is provided in the sealant, and an active gas is injected from this opening, The thing of the structure which seals an opening part is disclosed (for example, refer patent document 1).
Hereinafter, a specific example of the structure for sealing the opening of the touch panel will be described with reference to FIGS. FIG. 5 shows a touch panel in the prior art, FIG. 5 (a) is a plan view, FIG. 5 (b) is a cross-sectional view taken along line AA in FIG. 5 (a), and FIG. It is a partial expanded sectional view of the opening part vicinity for demonstrating a stop process.

  As shown in FIG. 5, the touch panel 10 has an upper substrate 1 and a lower substrate 2 arranged with a sealing agent 6 so that the transparent electrodes 3 and 4 face each other, and the peripheral portions of the upper and lower substrates 1 and 2 are It is stuck with the sealing agent 6 so that the fixed space | interval of about 8-12 micrometers may be maintained. The sealing agent 6 is provided with an opening 6 a of the sealing agent 6 in a part of the peripheral portion of the upper and lower substrates 1 and 2, and after the upper and lower substrates 1 and 2 are attached, gas is emitted from the opening 6 a of the sealing agent 6. It is injected and sealed with a sealing member 70.

  The lower substrate 2 is made of a soda glass plate having a thickness of 1.1 mm, and a transparent electrode 4 and routing electrodes 8 a and 8 b electrically connected to the transparent electrode 4 are formed on the soda glass plate. The other ends of the routing electrodes 8 a and 8 b are gathered on one side of the lower substrate 2 and connected to the end of the connector 9. The transparent electrode 4 is formed by patterning by etching an ITO film having a thickness of about 50 to 4000 mm by sputtering or CVD. The routing electrodes 8a and 8b are formed by printing a silver paste film having a thickness of about 1 to 20 μm and baking at 130 ° C. for about 60 minutes.

  Furthermore, dot spacers 5 are arranged in a matrix on the surface of the transparent electrode 4. The dot spacer 5 has a circular shape with a size of about 30 to 40 μm and a height from the substrate of about 7 to 12 μm. Further, the distance between the centers of the dot spacers 5 is set to about 4 to 5 mm. The dot spacers 5 are formed by printing an ultraviolet curable resin in a matrix and irradiating with ultraviolet rays to cure.

  The upper substrate 1 is made of a micro glass plate having a thickness of 0.2 mm, and similarly to the lower substrate 2, a transparent electrode 3 and routing electrodes 7a and 7b are formed. An example of the micro glass used as the upper substrate 1 is borosilicate glass.

  As the sealing agent 6, a thermosetting epoxy resin adhesive or the like is selected and formed with a width in the range of 1 to 2.5 mm. In addition, a spacer member such as a plastic ball or fiber glass having a required size is dispersed in the sealant 6, and this spacer member serves to hold the upper substrate 1 and the lower substrate 2 at a required interval. Is made.

  Next, a process for forming the sealant 6 and a process for sealing the opening will be briefly described. First, the sealant 6 is printed and formed near the periphery of the lower substrate 2 by a method such as screen printing. At this time, an opening 6b is provided in a part of the sealing agent 6 as shown in FIG. This opening 6b sets the pattern of the sealing agent 6 during printing so that the opening width increases from the outer peripheral side to the inner peripheral side of the sealing agent 6. In addition, the value of the width a of the opening on the outer peripheral side when the sealant 6 is printed is set to 3 to 8 mm, and the value of the opening width c on the inner peripheral side is set to about 8 to 15 mm.

  Next, as shown in FIG. 6B, the upper and lower substrates 1 and 2 are superposed, pressurized and heated for a predetermined time, the sealing agent 6 is baked, and the upper and lower substrates 1 and 2 are bonded together. At this time, the planar shape of the sealant 6 is expanded and the width b of the opening is slightly narrowed. However, the width b of the opening 6a on the outer peripheral side is 2 to 5 mm and the width d on the inner peripheral side in this bonded state. The pattern of the sealant 6 at the time of printing is formed so that is in the range of 5 to 10 mm.

  Next, as shown in FIG. 6C, gas is injected from the opening 6 a of the sealing agent 6, and then sealed with a sealing member 70. Thereby, the touch panel 10 in which the inside of the panel as shown in FIG. 5 is sealed is obtained. In this case, although not shown, sealing is performed by slightly increasing the internal pressure with respect to the external pressure so that the upper substrate 1 is slightly convexly curved outward by injecting gas from the opening 6a. This is performed in order to improve operability during data input and to prevent occurrence of interference fringes. In this sealing process, an adhesion method without heating was selected in order to avoid abnormal deformation of the upper substrate, and an acrylic resin-based ultraviolet curable adhesive was used as the sealing member 70. .

JP 10-133817 A (page 3)

  However, in the touch panel of the prior art, the epoxy resin-related adhesive used for the sealant 6 and the acrylic resin-related ultraviolet curable adhesive used as the sealing member 70 are bonded due to the difference in material. There was a problem that the familiarity with was bad, and there was a problem that airtightness could not be secured. For this reason, there is a possibility that a gap may be formed between the sealant 70 and the sealant 6 as shown in FIG. 7 under the environment of repeated data input or severe temperature change, and the upper substrate 1 is pressed during data input. There is a problem that the return (bounce) at the time of the operation becomes insufficient and the operability is deteriorated or the reliability is lowered. In addition, there is a problem in that the upper substrate 1 is deformed with time into a concave shape due to repeated input to the upper substrate 1 and interference fringes are generated, resulting in poor appearance. There is also a problem that the input screen is fogged due to moisture entering through the gap and increasing the internal humidity. Further, in the process of injecting gas from the opening 6a of the sealing agent 6, since the opening is one place, the vicinity of the opening of the upper substrate 1 is unevenly swollen, and it is difficult to properly control the curved shape. There was a problem.

(Object of invention)
The present invention solves the above-mentioned problems by using an adhesive that is a resin similar to the sealing agent and hardens at room temperature as a sealing member for sealing the opening of the sealing agent. An object of the present invention is to provide a touch panel that is light in pressure, excellent in operability and reliability, excellent in moisture resistance, and prevents interference fringes.

In order to achieve the above-described object, the touch panel according to the present invention is configured such that the upper and lower substrates on which a pair of transparent electrodes are arranged face each other through a sealing agent arranged along the periphery of the substrate with the transparent electrodes inside. In the touch panel in which the opening provided in the sealing agent is sealed with a sealing member, the sealing agent has a plurality of openings, and the openings are arranged along two opposite sides of the substrate. The sealing member for sealing the opening is made of an adhesive that is a resin material of the same system as the sealing agent and is cured at room temperature.
Further, the opening is disposed at a position that is substantially symmetrical with respect to the center of the substrate.

  As described above, according to the present invention, by using an adhesive that is a resin similar to the sealing agent and hardens at room temperature as the sealing member that seals the opening of the sealing agent, the opening is securely sealed by the sealing member. You can stop. For this reason, it is possible to obtain a touch panel with high sealing performance at the sealing portion and strong against both changes in internal and external pressure. Further, by providing a plurality of openings in the sealant and providing the openings at positions facing each other, gas injection is performed uniformly, and the curved shape of the upper substrate can be controlled appropriately. As a result, there is provided a touch panel that has a smooth return (bounce) when the upper substrate is pressed, a light pressing force at the time of data input, excellent operability and long-term reliability, and excellent moisture resistance and water resistance. I can do it. In addition, it is possible to realize a touch panel with good appearance by preventing generation of interference fringes.

  FIG. 1 is a view showing a state where an opening of a sealant of a touch panel in the present embodiment of the present invention is sealed, FIG. 1 (a) is a plan view, and FIG. 1 (b) is a B- in FIG. 1 (a). It is B sectional drawing. FIG. 2 is a plan view showing a state in which a sealant is printed on the lower substrate. 4 is a partially enlarged plan view showing the vicinity of the opening of the sealing agent. FIG. 4 (a) shows a state where the sealing agent is printed on the lower substrate, and FIG. 4 (b) shows the upper and lower substrates 1 and 2 with the sealing agent. FIG. 4C is a diagram showing a state where the openings are sealed with a sealant. The touch panel in the present embodiment is characterized by the opening of the sealing agent and the sealing member, and the other configurations are the same as the touch panel in the conventional example. Accordingly, the same parts as those in the conventional example are designated by the same reference numerals and the description thereof is omitted. Hereinafter, the touch panel according to the present embodiment will be described with reference to FIGS. 1, 2, and 4.

  As shown in FIG. 1, the touch panel 20 of the present embodiment has openings 16a and 16b at two locations of the sealing agent 16 for attaching the upper and lower substrates 1 and 2, and is sealed with sealing members 17a and 17b, respectively. ing. A thermosetting epoxy resin adhesive is used for the sealing agent 16, and a room temperature curing epoxy resin adhesive is used for the sealing members 17 a and 17 b for sealing the openings 16 a and 16 b. The sealing agent 16 is formed along the inner periphery of each side of the upper and lower substrates 1 and 2, and an opening is provided in the vicinity of the center of the sealing agent 16 formed along two opposing sides of the upper and lower substrates 1 and 2. 16a and 16b are provided, respectively. The positions where the openings 16a and 16b are provided are not particularly limited, but a gas is injected from the openings to keep the curved shape of the upper substrate 1 in an appropriate shape as shown in FIG. It is preferably provided at a position that is substantially symmetric with respect to the center of the substrate. Further, the openings 16a and 16b have a shape in which the opening width increases from the outer peripheral side to the inner peripheral side of the sealing agent 16, and the value of the width f of the outer peripheral opening is reduced to about ½ of the normal value. It is preferable to set. In this embodiment, it was set to 1.5 mm.

  Next, the formation process of a sealing agent and the sealing process of an opening part are demonstrated to this embodiment. First, as shown in FIG. 2, the sealing agent 16 is printed on the periphery of the lower substrate 2. The sealing agent 16 is used to bond the upper substrate 1 and the lower substrate 2 together, and a thermosetting epoxy resin adhesive is formed by a method such as screen printing. At this time, the value of the width k of the sealant 16 was set to 0.7 mm. In addition, a spacer member such as a plastic ball or fiber glass having a sphere diameter of about 8 μm is dispersed in the sealing agent 16, and the upper substrate 1 and the lower substrate 2 are spaced apart from each other by this spacer member. It has a role to hold in. In addition, openings 16c and 16d are formed in the vicinity of the center of each of the sealing agents 16 formed along two opposing sides of the four sides of the lower substrate 2. One opening 16c has a shape in which the opening width increases from the outer peripheral side to the inner peripheral side of the sealing agent 16 as shown in FIG. 4A, and the value of the width e of the opening on the outer peripheral side is 3 mm. The value of the opening width g on the peripheral side is printed and formed to about 10 mm. The other opening 16d is also printed and formed in the same shape.

  Next, with the lower substrate 2 on which the sealing agent 16 is printed facing down, the upper substrate 1 is superposed via the sealing agent 16, and the heating temperature is 150 ° C. and the applied pressure is 0.2 to 0.25 kg / cm 2. The sealant 16 is baked by holding for ˜90 minutes, and then gradually cooled. FIG. 4B is a partially enlarged plan view showing the vicinity of one opening 16 a in a state where the upper substrate 1 is adhered to the lower substrate 2 with the sealant 16. As shown in FIG. 4B, the sealant 16 is spread by heating and pressurization, the value of the width m of the sealant is 2 mm, and the value of the width f of the opening on the outer peripheral side of the sealant 16 is 1. The value of the opening width h on the inner peripheral side is 5 mm. The other opening 16b has the same shape.

  Next, after injecting air of about 1.1 atm from both openings 16a and 16b of the sealant 16, as shown in FIG. 4 (c), room temperature curing is performed on the opening 16a of one sealant 16. The mold was filled with a sealing member 17a made of an epoxy resin adhesive, and the sealing member 17a was cured to seal the opening 16a. As this room temperature curing type epoxy resin adhesive, it is preferable to use an epoxy resin adhesive having a curing time of about 30 minutes because of good workability. Similarly, the opening 16b of the other sealant 16 is filled with a sealing member 17b made of a room temperature curable epoxy resin adhesive, cured, and sealed, as shown in FIG. 1B. A touch panel 20 in which the inside is hermetically sealed and the curved shape of the upper substrate 1 is an appropriate shape is obtained.

  As described above, the touch panel 20 according to the present embodiment uses a thermosetting epoxy resin adhesive as the sealing agent 16, and seals as the sealing members 17a and 17b that seal the openings 16a and 16b of the sealing agent 16. By using a room temperature curing type epoxy resin adhesive as an adhesive that cures at room temperature, the familiarity at the interface between the sealing agent 16 and the sealing members 17a and 17b is improved, and the openings 16a and 16b are sealed. It can seal reliably by the stop members 17a and 17b. For this reason, it is possible to obtain a touch panel with high sealing performance and strong resistance to both internal and external pressure changes. Further, the sealing agent 16 has a plurality of openings 16a and 16b, and the openings 16a and 16b are provided at positions facing each other, so that the gas can be injected evenly and the curved shape of the upper substrate 1 can be appropriately adjusted. Can be controlled. As a result, a touch panel having a smooth return (bounce) when the upper substrate 1 is pressed, a light pressing force at the time of data input, excellent operability and long-term reliability, and excellent moisture resistance and water resistance is provided. I can do it. In addition, it is possible to realize a touch panel with good appearance by preventing generation of interference fringes.

In this embodiment, the example of forming the openings of the sealant at two locations and providing one opening on each of the two opposite sides has been described. However, depending on the size of the substrate as shown in FIG. As shown, one may be provided on each of the four sides and formed in four places.
Moreover, it is needless to say that the dimension value of each part near the opening of the sealing agent described in the present embodiment is not particularly limited and can be set according to the shape of the panel.

Moreover, in this embodiment, although the example using the room temperature curing type epoxy resin adhesive was demonstrated about the sealing member, you may use an epoxy-type ultraviolet curing adhesive.
Further, the sealing agent and the sealing member are not limited to epoxy adhesives, and it goes without saying that other adhesives can be used. For example, when an acrylic adhesive is used, an ultraviolet curable acrylic adhesive may be used as the sealing member.

It is a figure which shows the state which sealed the opening part of the sealing compound of the touchscreen in this embodiment of this invention, Fig.1 (a) is a top view, FIG.1 (b) is BB sectional drawing in Fig.1 (a). It is. It is a top view which shows the state which printed the sealing agent on the lower board | substrate in embodiment of this invention. It is a top view of the lower board | substrate which shows the other example in embodiment of this invention. It is a partial expanded plan view for demonstrating the sealing process of an opening part from the formation process of the sealing agent in embodiment of this invention. The touch panel in a prior art example is shown, Fig.5 (a) is a top view of a touchscreen, FIG.5 (b) is AA sectional drawing in Fig.5 (a). It is a partial enlarged plan view for demonstrating the sealing process of an opening part from the formation process of the sealing agent in a prior art example. It is a partial enlarged plan view for demonstrating the sealing state of the opening part of the sealing agent in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper substrate 2 Lower substrate 3 Transparent electrode 4 Transparent electrode 5 Dot spacer 6 Sealing agent 6a, 6b Sealing agent opening 7a, 7b Leading electrode 8a, 8b Leading electrode 9 Connector 10, 20 Touch panel 16 Sealing agent 16a, 16b, 16c , 16d Sealing agent openings 17a, 17b Sealing member 70 Sealing member

Claims (2)

  The upper and lower substrates on which a pair of transparent electrodes are arranged are arranged so as to face each other through a sealing agent arranged along the periphery of the substrate with the transparent electrode inside, and an opening provided in the sealing agent is formed by a sealing member. In the sealed touch panel, the sealant has a plurality of openings, and the openings are formed in the respective sealants disposed along two opposite sides of the substrate, and the openings are formed. A touch panel, wherein a sealing member to be sealed is made of an adhesive that is a resin material of the same system as the sealing agent and is cured at room temperature.   The touch panel according to claim 1, wherein the opening is disposed at a position that is substantially symmetrical with respect to a center of the substrate.

Images