JP2009015871A - Touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel on which an optical member is stuck so that it can be restuck. <P>SOLUTION: In the touch panel constituted by arranging a pair of panels (100, 200) having transparent conductive films (120, 220) stuck on one-surface sides of transparent substrates (110, 210) through a spacer (140) with electric insulation property so that the conductive film sides face each other, optical members (700a, 700b) are stuck on one or both of surfaces of the pair of panels on the opposite sides from the conductive films through re-released adhesive layers (600a, 600b) interposed therebetween and 90° release adhesive strength of each re-released adhesive layer to a substrate surface is 5 to 500 g/25 mm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pen input panel and a touch panel used for inputting to a personal computer, a word processor, an electronic notebook, and the like.

A resistive film type touch panel used on a display device such as an LCD, PDP, CRT, etc. has two transparent panels each having a transparent conductive film attached to a transparent substrate, and the conductive film sides face each other. Insulating spacers are arranged in the form of dots, electrodes are formed on the respective conductive films, circuits are connected, and one side of the substrate is pressed with a pen or finger to establish vertical conduction. The coordinates are detected by taking them.
Touch panels are being used in large quantities in wider fields not accompanied by the development of electronic devices. Accordingly, touch panels that can be manufactured more easily and more durable touch panels are strongly demanded. ing.

For example, two panels have a combination of top / bottom film / glass, film / plastic plate, film / film, etc., and the conductive film material is ITO (indium oxide / tin oxide) or tin oxide (SnO). ₂ ) is used, but it is necessary to divide the conductive film into the desired pattern and attach it to the surface of the substrate. Conventionally, the conductive film is deposited on the entire surface of the substrate by sputtering or the like and then etched. Thus, unnecessary portions have been removed.

  As the etching method, a photolithography method or a sand blast method is used, but the photolithography method uses a wet method using a liquid such as aqua regia or hydrochloric acid depending on the etching material, hydrofluoric acid (HF) or fluoriodic acid. There is a dry method using a gas such as (HI). The wet method has many processes such as application of photosensitive resin, drying, exposure development with a photomask, and drying. Also, in order to use dangerous liquids such as aqua regia and hydrochloric acid, liquid management and waste liquid treatment In addition, since the dry method uses dangerous gases such as hydrofluoric acid and fluoriodic acid, it requires a lot of capital investment for measures against gas leakage and exhaust gas treatment. .

  In addition, there is a method to remove unnecessary parts by sandblasting, but this method takes time, the mask that covers the necessary parts needs to be replaced frequently, and the management man-hour is large. There is also a problem that the strength is lowered due to scratching. Accordingly, there is a strong demand for a touch panel having a conductive film that is divided by simple work with low equipment costs.

  In addition, the upper / lower panel of the touch panel is bonded by double-sided tape at the periphery, but when the surface is pressed, it may be damaged by the edge of this double-sided tape and will not be damaged. A highly durable touch panel is required.

  In many cases, an optical member is attached to the surface of the touch panel via an adhesive layer, but the two may be peeled off when a foreign object or a bubble is attached during the operation. At that time, the touch panel and the optical member may be damaged and reattachment may not be possible. Therefore, in such a case, a touch panel to which an optical member is attached so as to be able to be attached again is sought.

  In view of the above problems, an object of the present invention is to provide a touch panel to which an optical member is attached so that it can be attached again.

According to the first aspect of the present invention, there is provided a touch panel in which a pair of panels each having a transparent conductive film attached to one surface of a transparent substrate are arranged via an electrically insulating spacer so that the conductive film side faces each other. ,
An optical member is attached to one or both anti-conductive film side surfaces of the pair of panels via a removable adhesive layer, and the 90 ° peel adhesive strength of the removable adhesive layer to the substrate surface is 5 to 500 g / 25 mm. A touch panel is provided.
According to the invention of claim 2, in the invention of claim 1, the removable adhesive layer is any one of an ethylene vinyl alcohol adhesive, a polyacrylic ester adhesive, a polymethacrylic ester adhesive, and a silicon adhesive. There is provided a touch panel mainly composed of the above.
According to the invention of claim 3, there is provided a touch panel according to the invention of claim 1, wherein the optical member is any one of a polarizing plate, a circularly polarizing plate and a retardation plate.

  In the touch panel of the present invention, the optical member is attached to one or both surfaces of the pair of panels on the side of the anti-conductive film via the removable adhesive layer, but the releasable adhesive layer is peeled 90 degrees from the substrate surface. The adhesive strength is 5 to 500 g / 25 mm, and the yield is improved because it is easy to execute again even if the sticking operation fails.

Hereinafter, embodiments of a touch panel according to the present invention will be described with reference to the accompanying drawings.
In the following description, the movable side panel means a substrate far from the display device pressed by a pen or a finger, and the fixed side panel means a substrate near the display device.
The front side means the input side, and the back side means the display device side.

  FIG. 1 is a view of the fixed side panel 100 of the touch panel in the first reference example of the present invention as viewed from the front side. The fixed side panel 100 is electrically conductive with ITO on the front side of a glass substrate 110 (see FIG. 4). After the film 120 (see FIG. 4) is deposited by sputtering, it is etched by a laser to form grooves 131, 132, 133, 134, 135 (shown by thick solid lines), and then dot spacers 140 are formed by screen printing. Further, silver electrode circuits 151, 152, 153, 154, 155, and 156 are additionally provided by printing. The grooves 1311 to 135 are formed so that regions of the conductive film 120 to which the electrode circuits 151, 152, 153, 154, 155, and 156 are connected are divided as desired.

  FIG. 2 is a view of the movable panel 200 as viewed from the front side, and an ITO conductive film 220 (see FIG. 4) is attached to the back side of a transparent resin film substrate 210 (see FIG. 4) by sputtering. Later, silver electrode circuits 251 and 252 are attached and formed by printing.

  FIG. 3 is a view of a double-sided tape 300 interposed between the fixed side panel 100 and the movable side panel 200 and joining the fixed side panel 100 and the movable side panel 200 as viewed from the front side. The fixed side panel 100 and the movable side panel 200 shown in FIGS. Reference numerals 301 and 302 indicate holes, which are provided with a conductive adhesive, and are connected to the electrode circuit 156 of the fixed side panel 100, the electrode circuit 252 of the movable side panel 200, and the fixed side. The electrode circuit 154 of the panel 100 is electrically connected to the electrode circuit 251 of the movable side panel 200.

  4 is a cross-sectional view of the state in which the fixed side panel 100 and the movable side panel 200 are joined by the double-sided tape 300, taken along the plane AA in FIG. The double-sided tape 300 is one in which an adhesive is applied to both sides of a thin film, but is shown integrally. In addition, since the adhesive is soft, the electrode circuits 152 and 153 enter the adhesive.

  In the first reference example of the present invention, the fixed side panel 100 is made as described above, and the conductive film 120 of the fixed side panel 100 is divided by the formation of grooves 131 to 135 using a laser. Compared to the photolithographic method, it can be manufactured easily in a much shorter time than the photolithographic method, and the equipment for dividing the conductive film is only one laser device and much less than the photolithographic method. I'm sorry. Further, since no dangerous liquid or gas is used, it is safe, and man-hours and facilities for managing and processing them are not required.

  In addition, since the photolithographic method uses a photomask, it is necessary to prepare another photomask for changing the division pattern. However, when the laser is used as in the present invention, the movement of the laser is controlled. Therefore, it can be done in a short time just by changing the software.

  Further, since the conductive film cannot be finely removed by the conventional technique as described above, it is necessary to remove the conductive film widely as shown by the hatched area in FIG. 5, and the fixing is performed as shown in FIG. The side panel 100 and the movable side panel 200 are joined.

As a laser for performing etching, a YAG laser is used in this embodiment, but a YLF laser, a YVO laser, a CO ₂ laser, or the like can also be used. As the laser light, light in the infrared region having a wavelength of 900 nm or more is preferably used, and the pulse width is preferably set to sub-nanosecond or less so as not to leave the thermal metamorphic layer in the conductive film 120. In addition, a larger laser spot diameter can surely form a groove in the conductive film 120, but if it is too large, energy is dispersed and sharp etching cannot be performed, so that the diameter is 0.1 mm to 2.0 mm. Is preferably used.

  A power connector (not shown) is attached to the fixed side panel 100 of the touch panel completed as described above in FIG. 1B. As shown in the figure, the electrode circuits 153, 154, 155, 156 For example, voltages of 0 volts, 5 volts, 0 volts, and 5 volts are applied, respectively. When the front side of the movable side panel 200 is pressed, the resistance is measured through the electrodes, the coordinate position is detected and input as input information to a control device (not shown), but the configuration is related to the present invention. Since there is no, explanation is omitted.

  Next, a modification of the first reference example will be described. This is because the conductive film 120 of the fixed-side panel 100 and the conductive film 220 of the movable-side panel 200 each extend to the outer peripheral end face, so that foreign matter adheres to bridge the conductive film 120 and the conductive film 220 at the end face. Then, there is a possibility of short-circuiting, so that such a thing will not occur.

  FIG. 7 is a view showing the fixed-side panel 100 in a modification of the first reference example, and a closed groove 136 that goes around the outer periphery is added to the first reference example. FIG. 8 is a sectional view taken along the line A ″ -A ″ of FIG. By doing so, the region including the end face is not electrically connected to the region where the power supply circuit is disposed, so that the short circuit as described above does not occur.

  As described above, the formation of the groove by laser etching has been described for the case where the groove is formed on the glass substrate 110 of the fixed side panel 100 on the conductive film 120. However, the groove formation by the laser etching is performed on the movable side panel 200. The present invention can also be applied to a substrate formed of a film like the substrate 210 of FIG.

  Next, a second reference example will be described. This prevents the conductive film 220 of the movable side panel 200 from being damaged by the double-sided tape 300. In addition, since the adhesive of the double-sided tape 300 is soft, it is the film (not shown) to which the adhesive panel is applied that damages the movable side panel 200.

  FIG. 9 is a diagram for explaining the characteristics of the second reference example, and a rubber elastic member 500 is attached to the movable side panel 200 so as to cover a portion of the movable side panel 200 where the edge of the double-sided tape 300 hits. Has been. By doing so, the edge of the double-sided tape 300 is prevented from hitting the conductive film 220 of the movable side panel 200, and the conductive film 220 is prevented from being damaged.

  FIG. 10 shows a first modification of the second reference example, corresponding to the case where the insulating layer 400 is provided between the fixed side panel 100 and the double-sided tape 300, and the elastic member 500 is located on the inner side. The extended edge of the insulating layer 400 is prevented from hitting the conductive film 220 of the movable panel 200.

  FIG. 11 shows a second modification of the second reference example in which the elastic member 500 is attached to the double-sided tape 300 instead of the movable side panel 200. FIG. 12 shows the second reference example. The third modification corresponds to the case where the insulating layer 400 is provided by the same method. Thus, even if the elastic member 500 is attached not to the movable side panel 200 but to the double-sided tape 300, the conductive film 220 can be prevented from being damaged.

  Although the second reference example and the modification thereof have been described by taking as an example a case where the conductive film is divided by a groove formed by laser etching as in the first reference example, Since the characteristic part is the structure as described above, the application range is not limited to the case where the conductive film is divided as in the first reference example. For example, the conventional photolithography method is used. It will be easily understood that the present invention can also be applied to the case where the conductive film is divided by the sandblast method.

Next, embodiments of the present invention will be described. First, the background will be described in detail.
In order to prevent reflection on the surface of the touch panel and improve visibility, an optical member such as a polarizing plate, a retardation plate, or a circular polarizing plate is provided on the front side of the movable side panel 200 or the back side of the fixed side panel 100. Is often attached via an adhesive layer. During this operation, foreign matter or bubbles may be mixed. In such a case, the optical member may be peeled off from the surface of the movable side panel 200 or the fixed side panel 100 and the operation may be repeated again. However, if the adhesive force of the adhesive layer is inappropriate, the residue may remain on the surface of the optical member, the movable side panel 200, and the fixed side panel 100, and when peeling, the optical member, the movable side panel 200, and the fixed side The panel 100 may be damaged, and these may not be reused and the yield may be deteriorated.

The embodiment of the present invention addresses such a problem, and the pressure-sensitive adhesive layer is a re-peelable pressure-sensitive adhesive layer having just good adhesive force that does not cause the above problems.
FIG. 13 is a cross-sectional view of the touch panel according to the embodiment of the present invention. A quarter wavelength plate 710 and a polarizing plate 720 are laminated in advance on the front side of the movable side panel 200 via a removable adhesive layer 600a. An optical member 700a made of a quarter-wave plate 710 is attached to the back side of the fixed panel 100 via a removable adhesive layer 600b.

  The adhesive layer 600a has a 90-degree peeling adhesive force of 5 g to 500 g / 25 mm with respect to the substrate 210 of the resin film of the movable side panel 200. Further, the adhesive layer 600b has a 90-degree peeling adhesive force to the glass substrate 110 of the fixed side panel 100 of 5 g to 500 g / 25 mm. The 90-degree peel adhesive strength of 500 g / 25 mm means that the force required to pull a 25 mm width in a direction perpendicular to the adhesive surface is 500 g.

  The re-peelable pressure-sensitive adhesive layer is preferably formed of an ethylene vinyl alcohol-based pressure-sensitive adhesive, a polyacrylic ester-based pressure-sensitive adhesive, a polymethacrylic ester-based pressure-sensitive adhesive, or a silicon-based pressure-sensitive adhesive, The transmittance is preferably 75% or more (JISZ8722) in the visible light region.

  By making the adhesive layer as a removable adhesive layer as described above, the optical members 700a and 700b, or the movable panel 200 and the fixed panel 100 are damaged or the adhesive remains when peeling. This is prevented and the yield is improved.

  Although the above-described embodiment of the present invention has been described by taking the case where the conductive film is divided by the groove formed by laser etching as in the first reference example, the embodiment of the present invention is described. Since the characteristic part of the form is the structure as described above, the application range is not limited to the case where the conductive film is divided as in the first reference example. It will be easily understood that the present invention can be applied to the case where the conductive film is divided by a photolithography method or a sand blast method.

It is a figure which shows the stationary side panel in the 1st reference example of this invention. It is a figure which shows the movable side panel in the 1st reference example of this invention. In the 1st reference example of this invention, it is a figure which shows the double-sided tape interposed between a fixed side panel and a movable side panel. In the 1st reference example of this invention, it is sectional drawing which cut the state which joined the fixed side panel and the movable side panel with the double-sided tape with the surface which passes along the AA line of FIG. It is a figure which shows the removal range of the electrically conductive film of the stationary side panel in a prior art. FIG. 6 is a cross-sectional view of the state in which the fixed side panel from which the conductive film has been removed is joined to the movable side panel with a double-sided tape as shown in FIG. 5 cut along a plane passing through line A′-A ′ in FIG. 5. It is a figure which shows the stationary side panel in the 1st modification of the 1st reference example of this invention. It is sectional drawing which cut the state which joined the fixed side panel of FIG. 7 with the movable side panel with the double-sided tape by the surface which passes along A "-A" line of FIG. It is a figure which shows the characteristic of the 2nd reference example. It is a figure which shows the characteristic of the 1st modification of a 2nd reference example. It is a figure which shows the characteristic of the 2nd modification of a 2nd reference example. It is a figure which shows the characteristic of the 3rd modification of a 2nd reference example. It is a figure explaining embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Fixed side panel 110 Glass substrate 120 (ITO) conductive film 131,132,133,134,135,136 Groove (formed by laser etching) 140 Spacers 151,152,153,154,155 (Silver) electrode circuit 200 Movable side panel 210 Film substrate 220 (ITO) conductive film 251 252 (made of silver) electrode circuit 300 double-sided tape 301,302 hole 400 insulating layer 500 (rubber) elastic member 600a, 600b adhesive layer 700a, 700b Optical member

Claims (3)

In a touch panel in which a pair of panels each having a transparent conductive film attached to one surface of a transparent substrate are arranged via an electrically insulating spacer so that the conductive film side faces,
An optical member is attached to one or both anti-conductive film side surfaces of the pair of panels via a removable adhesive layer, and the 90 ° peel adhesive strength of the removable adhesive layer to the substrate surface is 5 to 500 g / 25 mm. The touch panel characterized by being.   The re-peelable pressure-sensitive adhesive layer is mainly composed of any one of an ethylene vinyl alcohol pressure-sensitive adhesive, a polyacrylic ester-based pressure-sensitive adhesive, a polymethacrylic ester-based pressure-sensitive adhesive, and a silicon-based pressure-sensitive adhesive. Touch panel.   The touch panel according to claim 1, wherein the optical member is any one of a polarizing plate, a circularly polarizing plate, and a retardation plate.

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