JP2014191694A - Touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel that is used for various kinds of electric apparatuses having back side display elements easy-to-view and is capable of ensuring reliable operation.SOLUTION: The touch panel comprises: an upper conductive layer 8 formed over the lower surface of an upper board 1; and a lower conductive layer 7 formed over the upper surface of a lower board 2, either one of which is formed of a conductive resin. Plural concave and convex portions 7A and 8A are disposed on the interface between the upper conductive layer 8 and the lower conductive layer 7 with a distance smaller the wavelength of visible light; thereby recessing and projecting portions 7A and 8A with a distance smaller the wavelength of visible light are formed on the interface between the upper conductive layer 8 and the lower conductive layer 7. Since the reflection of light is extremely small, reflection of external light such as sunlight and lighting is reduced; and thereby the display of the rear display elements is easy to view and operate.

Description

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

  In recent years, as various types of electronic devices such as mobile phones and electronic cameras have become highly functional and diversified, a light-transmissive touch panel is mounted on the front surface of a display element such as a liquid crystal display element, and the display element on the back side is attached through this touch panel. By touching the touch panel with a finger or pen while watching the display, there are an increasing number of devices that switch various functions of the device. It has been demanded.

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

  In addition, in this drawing, in order to make the configuration easy to understand, the dimensions are partially enlarged.

  FIG. 4 is a cross-sectional view of a conventional touch panel, in which 1 is a film or plate and is a light transmissive upper substrate, 2 is a light transmissive 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 on the upper surface.

  In addition, a plurality of dot spacers (not shown) are formed on the upper surface of the lower conductive layer 4 by insulating resin at a predetermined interval, and a pair of upper electrodes (such as silver and carbon) are formed on the left and right ends of the upper conductive layer 3. (Not shown), a pair of lower electrodes (not shown) are formed at front and rear ends in a direction orthogonal to the upper conductive layer 3 of the lower conductive layer 4, and the end portions of the upper electrode and the lower electrode are Each of the upper substrate 1 and the lower substrate 2 extends to the front end of the outer periphery.

  Further, reference numeral 5 denotes a substantially frame-shaped spacer formed at the inner periphery of the outer periphery between the upper substrate 1 and the lower substrate 2, and the upper substrate is coated with an adhesive (not shown) applied to the upper and lower surfaces or one surface of the spacer 5. 1 and the outer periphery of the lower substrate 2 are bonded together, and the upper conductive layer 3 and the lower conductive layer 4 face each other with a predetermined gap therebetween to constitute a touch panel.

  The touch panel configured in this manner is disposed on the front surface of a display element such as a liquid crystal display element and attached to an electronic device, and a pair of upper and lower electrodes extending to the front end of the outer periphery are connected to a flexible wiring board or It is electrically connected to an electronic circuit (not shown) of the device via a connector (not shown) or the like.

  In the above configuration, when the upper surface of the upper substrate 1 on the desired display is pressed with a finger or a pen while viewing the display of the display element on the back through the touch panel, the upper conductive layer is bent 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 pair of upper and lower electrodes, and the electronic circuit detects the pressed portion by the voltage ratio between both ends of the upper conductive layer 3 and both ends of the lower conductive layer 4 in the direction orthogonal thereto. Various functions of the device are switched.

  That is, when, for example, a plurality of menus are displayed on the display element on the back surface of the touch panel, when the upper surface of the upper substrate 1 on the desired menu is pressed, the voltage ratio between the upper conductive layer 3 and the lower conductive layer 4 The electronic circuit detects the operated position, and a desired menu is selected from a plurality of menus.

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

JP 2012-59191 A

  However, in the above-described conventional touch panel, when the touch panel is disposed on the front surface of a display element such as a liquid crystal display element, the upper conductive layer 3 and the lower conductive layer have a refractive index of 1 above the upper substrate 1 and in the gap. 4 has a large difference in refractive index between 1.8 and 2, so that external light such as sunlight and electric light entering the upper substrate 1 and the gap from above is reflected on the upper conductive layer 3. In addition, there is a problem that reflection on the upper surface of the lower conductive layer 4 may make it difficult to see the display on the back display element due to the reflected light.

  The present invention solves such a conventional problem, and an object of the present invention is to provide a touch panel in which the display on the back display element is easy to see and can be reliably operated.

  In order to achieve the above object, according to the present invention, at least one of the upper conductive layer formed on the lower surface of the upper substrate or the lower conductive layer formed on the upper surface of the lower substrate is formed of a conductive resin, A touch panel is formed by providing a plurality of concave and convex portions with intervals smaller than the wavelength of visible light, and concave and convex portions with intervals smaller than the wavelength of visible light are formed on the opposing surface of the upper conductive layer and the lower conductive layer. Because the reflection of light is very small, the reflection of external light such as sunlight and electric light is reduced, and it is easy to see the display of the display element on the back, and a touch panel capable of reliable operation can be obtained. It has an action.

  As described above, according to the present invention, it is possible to obtain an advantageous effect that it is possible to realize a touch panel in which the display of the display element on the back surface is easy to see and can be reliably operated.

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

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  These drawings are partially enlarged in size for easy understanding of the configuration.

  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, reference numeral 1 denotes a film shape such as polyethylene terephthalate, polyethersulfone, or polycarbonate, or a plate shape such as glass or acrylic. A light transmissive upper substrate 2 is also a film or plate and is a light transmissive lower substrate. On the lower surface of the upper substrate 1 is a substantially rectangular light transmissive upper conductive layer such as indium tin oxide or tin oxide. 3 is formed by sputtering or the like.

  The upper surface of the lower substrate 2 is made of a light-transmitting conductive resin such as acrylate or methacrylate in which a plurality of silver fine wires, hollow carbon fine wires, carbon particles or the like are dispersed, or polythiophene or polyaniline. A plurality of concave and convex portions 7A having a height of about 0.1 to 0.5 μm and a diameter of about 0.05 to 0.3 μm are formed on the upper surface, which is a surface facing the conductive layer 3, with a visible light wavelength of 0.4. A lower conductive layer 7 formed at intervals of about 0.1 to 0.5 μm, which is smaller than about 0.8 μm, is provided.

  In addition, a plurality of dot spacers (not shown) are formed on the upper surface of the lower conductive layer 7 by an insulating resin such as epoxy and silicone at predetermined intervals, and silver and carbon are formed on the left and right ends of the upper conductive layer 3. A pair of upper electrodes (not shown) are formed at the front and rear ends in the direction orthogonal to the upper conductive layer 3 of the lower conductive layer 7, and a pair of lower electrodes (not shown) are formed respectively. Are extended to the front peripheral ends of the upper substrate 1 and the lower substrate 2, respectively.

  Furthermore, 5 is a substantially frame-like spacer made of polyester, epoxy, nonwoven fabric, etc., which is formed on the outer peripheral inner edge between the upper substrate 1 and the lower substrate 2, and acrylic or The outer periphery of the upper substrate 1 and the lower substrate 2 is bonded together by an adhesive (not shown) such as rubber, and the upper conductive layer 3 and the lower conductive layer 7 are opposed to each other with a predetermined gap therebetween to form a touch panel. Yes.

  Further, in order to manufacture such a lower conductive layer 7 on the upper surface of the lower substrate 2, a conductive resin thin film 7B formed on the entire upper surface of the lower substrate 2 as shown in the partial sectional view of FIG. As shown in FIG. 2 (b), the upper surface is pressed with a press die 10 having a plurality of concave and convex portions 10A formed on the lower surface while heating at a temperature of about 100 to 150 degrees C. The lower conductive layer 7 having a plurality of concave and convex portions 7A provided on the upper surface as shown in FIG.

  That is, by forming the lower conductive layer 7 with a conductive resin instead of a metal thin film such as indium tin oxide or tin oxide, a plurality of layers are formed on the upper surface of the lower conductive layer 7 by a simple method such as pressing as described above. It is possible to provide the uneven portion 7A.

  The touch panel configured in this manner is disposed on the front surface of a display element such as a liquid crystal display element and attached to an electronic device, and a pair of upper and lower electrodes extending to the front end of the outer periphery are connected to a flexible wiring board or It is electrically connected to an electronic circuit (not shown) of the device via a connector (not shown) or the like.

  In the above configuration, when the upper surface of the upper substrate 1 on the desired display is pressed with a finger or a pen while viewing the display of the display element on the back through the touch panel, the upper conductive layer is bent and the upper conductive layer is pressed. 3 contacts the lower conductive layer 7.

  Then, a voltage is sequentially applied from the electronic circuit to the pair of upper and lower electrodes, and the electronic circuit detects the pressed portion by the voltage ratio between both ends of the upper conductive layer 3 and both ends of the lower conductive layer 7 in the direction orthogonal thereto. Various functions of the device are switched.

  That is, when, for example, a plurality of menus are displayed on the display element on the back surface of the touch panel and the upper surface of the upper substrate 1 is pressed on a desired menu, the voltage ratio of the upper conductive layer 3 and the lower conductive layer 7 An electronic circuit detects the operated position, and a desired menu is selected from a plurality of menus.

  At this time, in the present invention, the upper surface of the lower conductive layer 7 formed on the upper surface of the lower substrate 2 is provided with a plurality of concavo-convex portions 7A having an interval smaller than the wavelength of visible light. Since the reflection of the light is extremely small, external light such as sunlight and electric light entering the upper substrate 1 and the gap from above is prevented from being reflected by the lower conductive layer 7, and the display element on the back of the touch panel Is easy to see.

  In other words, at the interface between the air in the gap and the metal thin film such as indium tin oxide or tin oxide, the refractive index changes abruptly so that reflection of external light occurs, but a plurality of gaps formed at intervals smaller than the wavelength of visible light. In the concavo-convex portion 7A, since the refractive index changes slowly, the reflection of external light on the lower conductive layer 7 becomes very small, the display on the back display element is easy to see, and there is no erroneous operation. It is comprised so that it can do.

  In the above description, a configuration in which a plurality of concave and convex portions 7A having an interval smaller than the wavelength of visible light is provided only on the upper surface of the lower conductive layer 7 on the lower substrate 2 is shown in the cross-sectional view of FIG. As described above, the lower conductive layer 8 lower surface of the upper substrate 1 is also provided with a plurality of concave and convex portions 8A having an interval smaller than the wavelength of visible light, thereby reducing the reflection of the upper conductive layer 8 or The present invention can be implemented even when the plurality of concave and convex portions 8A are formed only on the lower surface of the conductive layer 8.

  In addition, when a plurality of uneven portions 7A and 8A are provided on the upper surface of the lower conductive layer 7 and the lower surface of the upper conductive layer 8, the intervals between the uneven portions 7A and 8A are formed differently as shown in FIG. Or by forming one of them in a shape that undulates vertically, the upper surface of the upper substrate 1 is pressed, the upper substrate 1 bends and the upper conductive layer 8 comes into contact with the lower conductive layer 7 and so on. And more reliable operation is possible.

  In the present invention, the lower conductive layer 7 and the upper conductive layer 8 are not formed of a metal thin film such as indium tin oxide or tin oxide, but are formed of a conductive resin. A plurality of concave and convex portions 7A and 8A can be easily formed on the upper surface of the conductive layer 7 and the lower surface of the upper conductive layer 8.

  Further, by forming the lower conductive layer 7 and the upper conductive layer 8 with a conductive resin having a refractive index of around 1.5 and equivalent to the lower substrate 2 and the upper substrate 1, the lower conductive layer 7 and the lower substrate 2, Reflection of external light at the interface between the upper conductive layer 8 and the upper substrate 1 is also greatly reduced, so that the display of the display element on the back surface can be seen more easily.

  As described above, according to the present embodiment, at least one of the upper conductive layer 8 formed on the lower surface of the upper substrate 1 or the lower conductive layer 7 formed on the upper surface of the lower substrate 2 is formed of the conductive resin. By providing a plurality of concave and convex portions 7A and 8A having an interval smaller than the wavelength of visible light on the upper surface of the lower conductive layer 7 and the lower surface of the upper conductive layer 8 which are opposite surfaces, the upper conductive layer 8 and the lower conductive layer 7 Since the concave and convex portions 7A and 8A having an interval smaller than the wavelength of visible light are formed on the opposite surface and the reflection of light is very small, the reflection of external light such as sunlight and electric light is reduced, and the back surface It is possible to obtain a touch panel that allows easy display and easy operation.

  The touch panel according to the present invention has an advantageous effect that the display on the display element on the back surface is easy to see and can be reliably operated, and is mainly useful for operation of various electronic devices.

DESCRIPTION OF SYMBOLS 1 Upper substrate 2 Lower substrate 3 Upper conductive layer 5 Spacer 7 Lower conductive layer 7A, 8A Uneven portion 8 Upper conductive layer 10 Press mold 10A Uneven portion

Claims (1)

An upper substrate having an upper conductive layer formed on a lower surface and a lower substrate having an upper surface formed with a lower conductive layer facing the upper conductive layer with a predetermined gap on the upper surface. A touch panel in which one side is formed of a conductive resin and a plurality of concave and convex portions having an interval smaller than the wavelength of visible light are provided on the opposite surface.

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