JP2007316704A - Touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel with satisfactory visibility and easy operability, as to the touch panel used for various kinds of electronic equipment. <P>SOLUTION: Oxygen and nitrogen are prevented from being released from an upper substrate 1 by a gas barrier layer 9 even when used under a high temperature condition, by forming an upper conductive layer 3 on an under face and the gas barrier layer 9 on an upper substrate 1 upper face, and by sticking a polarizing plate 6 on the upper face, to prevent generation of bubbles in an adhesive layer 7, and to obtain the touch panel with satisfactory visibility. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a touch panel used mainly for operating various electronic devices.

  In recent years, as various electronic devices such as mobile phones and car navigation systems have become more sophisticated and diversified, a light-transmissive touch panel is attached to the front surface of a display element such as a liquid crystal display, and the display element on the rear side is passed through this touch panel. There is an increasing number of devices that switch each function of a device by pressing the touch panel with a finger or a pen while visually recognizing the display, and there is a demand for a device that has excellent visibility and is easy to operate.

  Such a conventional touch panel will be described with reference to FIG.

  In addition, in order to make the structure easy to understand, the drawing shows an enlarged dimension in the thickness direction.

  FIG. 2 is a cross-sectional view of a conventional touch panel. In FIG. 2, 1 is a film-like upper substrate such as a light-transmitting polycarbonate, 2 is a light-transmitting lower substrate, and the lower surface of the upper substrate 1 is oxidized. A light transmissive upper conductive layer 3 such as indium tin is formed on the upper surface of the lower substrate 2, and a lower conductive layer 4 is also formed thereon.

  A plurality of dot spacers (not shown) are formed on the upper surface of the lower conductive layer 4 by an insulating resin at predetermined intervals, and a pair of upper electrodes (not shown) are formed at both ends of the upper conductive layer 3. At both ends of the lower conductive layer 4, a pair of lower electrodes (not shown) perpendicular to the upper electrode are formed.

  Reference numeral 5 denotes a frame-like spacer, and the outer periphery of the upper substrate 1 and the lower substrate 2 is bonded to each other by an adhesive (not shown) applied to the upper and lower surfaces or one surface of the spacer 5. The lower conductive layer 4 opposes with a predetermined gap.

  Furthermore, 6 is a polarizing plate in which triacetyl cellulose or the like is laminated on the upper and lower surfaces of polyvinyl alcohol in which iodine or a dye is oriented. This polarizing plate 6 is adhered to the upper surface of the upper substrate 1 by an adhesive layer 7 to constitute a touch panel. Has been.

  The touch panel configured in this manner is disposed on the front surface of a liquid crystal display element or the like and attached to an electronic device, and a pair of upper and lower electrodes are connected to an electronic circuit (not shown) of the device. .

  In the above configuration, when the upper surface of the polarizing plate 6 is pressed with a finger or a pen while visually recognizing the display of the liquid crystal display element on the back of the touch panel, the upper substrate 1 is bent together with the polarizing plate 6 and the upper conductive layer is pressed. 3 contacts the lower conductive layer 4.

  Then, a voltage is sequentially applied from the electronic circuit to the upper electrode and the lower electrode, and the electronic circuit detects the pressed portion by the voltage ratio between these electrodes, and various functions of the device are switched.

  At this time, when external light such as sunlight and lamps from above passes through the polarizing plate 6, the light wave in the X direction and the Y direction perpendicular to the X direction is a straight line only in one direction by the polarizing plate 6. It becomes polarized light and enters the upper substrate 1 from the polarizing plate 6.

  Then, this light passes through the upper substrate 1 and is reflected upward by the lower conductive layer 4. Since this reflected light is substantially halved by the polarizing plate 6 as described above, it is reflected from the upper surface of the polarizing plate 6. Therefore, the liquid crystal display element on the back surface is easy to see.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2006-107015 A

  However, in the conventional touch panel, when the surroundings are used at a high temperature, such as in an automobile room under direct sunlight, the upper substrate 1 is easy to adsorb oxygen and nitrogen, and the upper conductive material on the lower surface thereof. Since the layer 3 and the polarizing plate 6 affixed to the upper surface are difficult to pass gas or the like, as shown in FIG. 2, oxygen and nitrogen released from the upper substrate 1 due to heat are absorbed by the upper substrate 1 and the polarizing plate. 6 is accumulated in the adhesive layer 7 between 6 and bubbles 8 are generated, and external light is reflected on the bubbles 8 to make it difficult to see the liquid crystal display element on the back surface and the visibility is impaired.

  The present invention solves such a conventional problem, and an object of the present invention is to provide a touch panel with good visibility by preventing the generation of bubbles and the like even when used at high temperatures.

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, a gas barrier layer is formed on the upper surface of an upper substrate having an upper conductive layer formed on the lower surface, and a polarizing plate is attached to the upper surface to constitute a touch panel. Even when used in a state, the gas barrier layer can prevent the release of oxygen and nitrogen from the upper substrate, so there is no generation of bubbles in the adhesive layer, and a touch panel with good visibility can be obtained. It has the action.

  The invention according to claim 2 is the invention according to claim 1, wherein the gas barrier layer is formed of an inorganic oxide, and oxygen and nitrogen from the upper substrate are more reliably compared to the organic gas barrier layer. It has the effect | action that discharge | release of can be prevented.

  As described above, according to the present invention, it is possible to obtain an advantageous effect that a touch panel with good visibility and easy operation can be realized.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG.

  In addition, in order to make the structure easy to understand, the drawing shows an enlarged dimension in the thickness direction.

  Further, the same reference numerals are given to the same components as those described in the background art section, and the detailed description will be simplified.

(Embodiment)
FIG. 1 is a cross-sectional view of a touch panel according to an embodiment of the present invention. In FIG. 1, 1 is a film such as polyethersulfone or polycarbonate and is an optically transparent upper substrate, 2 is glass or acrylic, polycarbonate, etc. A light-transmitting lower substrate, a light-transmitting upper conductive layer 3 such as indium tin oxide or tin oxide on the lower surface of the upper substrate 1, and a lower conductive layer 4 on the upper surface of the lower substrate 2 are also sputtered. Etc., respectively.

  A gas barrier layer 9 made of an inorganic oxide such as silica, titanium oxide, alumina, indium tin oxide or the like is provided on the upper surface of the upper substrate 1 by vapor deposition or sputtering. Is covered with the gas barrier layer 9 and the upper conductive layer 3.

  A plurality of dot spacers (not shown) are formed on the upper surface of the lower conductive layer 4 by an insulating resin such as epoxy or silicon at a predetermined interval, and a pair of silver, carbon, or the like is formed at both ends of the upper conductive layer 3. A pair of lower electrodes (not shown) perpendicular to the upper electrode are formed at both ends of the lower conductive layer 4.

  Further, reference numeral 5 denotes a frame-like spacer such as polyester or epoxy, and an adhesive (not shown) such as acrylic or rubber applied and formed on the upper and lower surfaces or one surface of the spacer 5 to fix the upper substrate 1 and the lower substrate 2. The outer periphery is bonded, and the upper conductive layer 3 and the lower conductive layer 4 face each other with a predetermined gap.

  Reference numeral 6 denotes a flexible polarizing plate in which triacetyl cellulose or the like is laminated on the upper and lower surfaces of polyvinyl alcohol which has been adsorbed with iodine or a dye and stretched / oriented. This polarizing plate 6 is an adhesive layer made of acrylic or rubber. 7 is attached to the upper surface of the upper substrate 1 to constitute a touch panel.

  In addition, the touch panel configured in this manner is disposed on the front surface of a liquid crystal display element or the like and attached to an electronic device, and a pair of upper and lower electrodes are connected to an electronic circuit (not shown) of the device. .

  In the above configuration, when the upper surface of the polarizing plate 6 is pressed with a finger or a pen while visually recognizing the display of the liquid crystal display element on the back of the touch panel, the upper substrate 1 is bent together with the polarizing plate 6 and the upper conductive layer is pressed. 3 contacts the lower conductive layer 4.

  Then, a voltage is sequentially applied from the electronic circuit to the upper electrode and the lower electrode, and the electronic circuit detects the pressed portion by the voltage ratio between these electrodes, and various functions of the device are switched.

  At this time, when the external light such as sunlight and lamps from above passes through the polarizing plate 6, among the light waves in the X direction and the Y direction perpendicular thereto, for example, the polarizing plate 6 is a light wave in the Y direction. Is absorbed into the upper substrate 1 from the polarizing plate 6 as linearly polarized light in the X direction.

  Then, this light passes through the upper substrate 1 and is reflected upward by the lower conductive layer 4. Since this reflected light is substantially halved by the polarizing plate 6 as described above, it is reflected from the upper surface of the polarizing plate 6. The liquid crystal display element on the back is easy to see.

  Furthermore, since the gas barrier layer 9 is formed on the upper surface of the upper substrate 1 as described above, even when the surroundings are used at a high temperature, such as in an automobile interior under direct sunlight, the gas barrier layer 9 The release of oxygen and nitrogen from the upper surface of the upper substrate 1 can be prevented.

  That is, by forming a gas barrier layer 9 on the upper surface of the upper substrate 1 that is difficult to pass gas or the like with an inorganic oxide, release of oxygen and nitrogen from the inside of the upper substrate 1 due to heat is prevented, and a liquid crystal display element on the rear surface is It is configured such that bubbles or the like in the adhesive layer 7 that hinder the visibility of the image are not generated.

  The gas barrier layer 9 can also be formed by applying an organic resin such as acrylic on the upper surface of the upper substrate 1. However, the gas barrier layer 9 can be formed at a higher density by forming the gas barrier layer 9 with an inorganic oxide. High barrier properties can be obtained.

  As described above, according to the present embodiment, the gas barrier layer 9 is formed on the upper surface of the upper substrate 1 having the upper conductive layer 3 formed on the lower surface, and the polarizing plate 6 is pasted on the upper surface, thereby being used in a high temperature state. Even in such a case, the gas barrier layer 9 can prevent release of oxygen and nitrogen from the upper substrate 1, so that there is no generation of bubbles in the adhesive layer 7 and a touch panel with good visibility can be obtained. Is.

  In addition, by forming the gas barrier layer 9 with an inorganic oxide, it is possible to more reliably prevent the release of oxygen and nitrogen from the upper substrate 1 as compared with an organic gas barrier layer or the like.

  In the above description, a polarizing plate 6 is attached to the upper surface of the upper substrate 1 to prevent only reflection of external light from above. The present invention also applies to a so-called circularly polarized light type in which a quarter-wave retardation plate is provided between the lower substrate 2 and the lower surface of the lower substrate 2 to improve the visibility of a liquid crystal display element on the back surface in addition to reflection of external light. Can be implemented.

  In the above description, the structure in which the single gas barrier layer 9 is formed on the upper surface of the upper substrate 1 has been described. However, inorganic oxides such as silica, titanium oxide, niobium oxide, copper oxide, and tin oxide are alternately used. By stacking and forming a multi-layer gas barrier layer on the upper surface of the upper substrate 1, in addition to preventing the release of oxygen and nitrogen from the upper substrate 1 as described above, this gas barrier layer absorbs external light from above. Thus, reflection of light on the upper surface of the gas barrier layer can be prevented, and visibility can be further improved.

  The touch panel according to the present invention has an advantageous effect that it can provide an easy-to-operate device with good visibility, and is mainly useful for operating various electronic devices.

Sectional drawing of the touchscreen by one embodiment of this invention Cross-sectional view of a conventional touch panel

Explanation of symbols

1 Upper substrate 2 Lower substrate 3 Upper conductive layer 4 Lower conductive layer 5 Spacer 6 Polarizing plate 7 Adhesive layer 9 Gas barrier layer

Claims (2)

A light transmissive upper substrate having an upper conductive layer formed on the lower surface, a light transmissive lower substrate having an upper conductive layer formed on the upper surface and facing the upper conductive layer with a predetermined gap therebetween, and the upper substrate A touch panel comprising a polarizing plate attached to an upper surface and having a gas barrier layer formed on the upper surface of the upper substrate. The touch panel according to claim 1, wherein the gas barrier layer is formed of an inorganic oxide.

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