JP6044308B2 - Electrostatic touch panel - Google Patents

Description

  The present invention relates to an electrostatic touch panel.

  2. Description of the Related Art Conventionally, for example, an input / output device disclosed in Patent Document 1 has a configuration including a protective cover with which a finger comes in contact and a touch panel sensor whose capacitance changes in response to the finger's contact with the protective cover. ing. In such a configuration, the protective cover and the touch panel sensor are bound to each other by the adhesive layer.

  In the above configuration, a material that generates gas due to changes over time may be used for an input unit such as a protective cover. For example, Patent Document 2 describes that bubbles are generated in the shock-absorbing pressure-sensitive adhesive layer constituting the polarizing plate. In order to suppress the generation of gas that causes such bubbles, in the polarizing plate of Patent Document 2, a gas permeation suppression layer that suppresses the permeation of gas is provided between the shock-absorbing pressure-sensitive adhesive layer and the plastic plate. Yes.

JP 2012-146297 A JP 2008-143931 A

  However, if the configuration disclosed in Patent Document 2 is applied to an electrostatic touch panel and the input unit is covered with a gas permeation suppression layer, the gas generated from the input unit stays at the interface between the input unit and the gas permeation suppression layer. And can grow into bubbles by bonding. Such bubbles change the distance between an electrode member such as a touch panel sensor and the input unit. Therefore, the value of the electrostatic capacitance generated between the finger brought into contact with the contact surface and the electrode member is also changed by the bubbles. Therefore, the sensitivity of the operation with fingers detected by the electrostatic touch panel may be deteriorated with the passage of time.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an electrostatic touch panel that can reduce a change in capacitance with time between an input operation body such as a finger and an electrode member. It is to provide.

  The invention for achieving the above object is characterized by the following points. In addition, the code | symbol in the parenthesis described in the claim shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: It does not limit the technical scope of invention. Absent.

The present invention includes an input unit (12) having a contact surface (11) with which an input operation body (2) contacts, and an electrode member (20) whose capacitance changes according to the contact of the input operation body with the contact surface. The gas inflow layer (40) which covers the opposing surface (12a) of the input portion facing the electrode member and into which the gas generated from the input portion flows, and the binder (30) for binding the gas inflow layer and the electrode member ) and comprises a gas inlet layer, the gas flowing from the input unit, and the electrostatic touch panel you discharged to the outside from between the input portion and the electrode member.

  According to the present invention, the gas generated from the input part can flow into the gas inflow layer covering the facing surface facing the electrode member in the input part. Therefore, the situation where the above-mentioned gas is combined between the input portion and the electrode member and grows into bubbles is avoided. By suppressing the change in the distance between the input unit and the electrode member in this manner, the change with time in the capacitance generated between the input operation body and the electrode member brought into contact with the contact surface is reduced.

It is a front view which shows the electrostatic touch panel by one Embodiment of this invention. It is a figure which shows the structure of an input part, Comprising: It is the II-II sectional view taken on the line of FIG.

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

  An electrostatic touch panel 1 according to an embodiment of the present invention shown in FIGS. 1 and 2 is installed on an instrument panel in a vehicle cabin. The electrostatic touch panel 1 is exposed to the interior of a vehicle to form a design surface, and has a plurality of switch operation surfaces 11 that are operated to be touched by an operator's fingers 2. For example, when the operator touches the switch operation surface 11 with the finger 2, the air conditioner is activated, and the operation state of the air conditioner is displayed on the liquid crystal display unit 13.

  The electrostatic touch panel 1 includes a film sensor 20, a detection circuit 50, a housing 10, an adhesive material 30, a light source 60, a buffer layer 40, and the like. Here, the switch operation surface 11 in the present embodiment corresponds to the contact surface described in the claims, and the finger 2 in the present embodiment corresponds to the input operation body described in the claims. The film sensor 20 in the present embodiment corresponds to the electrode member described in the claims, and the adhesive material 30 in the present embodiment corresponds to the binder described in the claims. Furthermore, the buffer layer 40 in the present embodiment corresponds to a gas inflow layer described in the claims.

  The film sensor 20 is configured by providing an electrode 22 on a resinous insulating film 21. The insulating film 21 and the electrode 22 have translucency. In the film sensor 20, the capacitance generated between the electrode 22 and the switch operation surface 11 changes according to the contact of the finger 2 with the switch operation surface 11 of the housing 10.

  The electrode 22 is made of ITO (indium tin oxide) or a transparent conductive polymer. The area of the electrode 22 is slightly larger than the area of the switch operation surface 11. The end of the electrode 22 is electrically connected to the detection circuit 50 through a connector with silver paste or the like. The electrode 22 generates capacitance between the finger 2 in contact with or very close to the switch operation surface 11. The capacitance generated between the finger 2 and the electrode 22 changes according to the distance between the finger 2 and the switch operation surface 11.

  The detection circuit 50 is connected to the electrode 22 and detects a capacitance value generated between the finger 2 and the electrode 22. The detection circuit 50 determines whether or not there is an operation on the switch operation surface 11 based on whether or not the capacitance value acquired from the electrode 22 exceeds a preset threshold value. This threshold value is defined in advance by experiment or calculation so that the presence / absence of the operation is determined by the detection circuit 50 by the contact operation of the finger 2 on the switch operation surface 11.

  The housing 10 is formed by printing a light-shielding paint on a resin material having translucency. A plurality of input units 12 are formed in the housing 10. The outer surface exposed so that the finger 2 can come into contact with these input sections 12 functions as a switch operation surface 11 for operating the switch. The above-described light-shielding paint is not printed on the portions where each design is formed on each switch operation surface 11. Therefore, each switch operation surface 11 can emit light from the design portion.

  In addition, the housing 10 is bonded to the film sensor 20 by an adhesive material 30. The housing 10 is made of polycarbonate or the like, for example, and generates gas due to changes over time. The gas generated from the housing 10 is air that has entered the interior of the material when the housing 10 is molded or a gas resulting from a chemical reaction of the material forming the housing 10.

  The adhesive material 30 is a so-called double-sided tape that is formed in a sheet shape of about 50 μm and can adhere both surfaces to other objects. The adhesive material 30 is a so-called base-material-free double-sided tape that does not have a base material, and is formed of an acrylic pressure-sensitive adhesive that hardly allows gas to pass therethrough. The adhesive material 30 is provided between the switch operation surface 11 and the electrode 22, and binds the buffer layer 40 and the film sensor 20. The adhesive material 30 can transmit light.

  The light source 60 is a light emitting diode or the like, and is located on the opposite side of the input unit 12 with the film sensor 20 interposed therebetween. The light source 60 emits light toward the switch operation surface 11. Light from the light source 60 passes through the film sensor 20, the adhesive material 30, the buffer layer 40, and the input unit 12 in order, and is emitted from the design of the switch operation surface 11 toward the operator. Therefore, when the light source 60 is turned on, it is visually recognized that the switch operation surface 11 at a position facing the light source 60 is turned on.

  The buffer layer 40 shown in FIG. 2 is formed on the inner surface of the housing 10 by printing, painting, or the like. The buffer layer 40 is formed of, for example, about 20 micrometers (μm) using, for example, an acrylic paint, and can transmit light. The buffer layer 40 is formed so as to cover at least the facing surfaces 12 a of the input units 12. The facing surface 12 a is a range facing the electrode 22 in the inner surface of the housing 10. The facing surface 12 a is located on the side opposite to the switch operation surface 11 in the input unit 12.

  In addition, a plurality of minute holes 44 are formed in the buffer layer 40 (illustrated in a schematic enlarged manner in FIG. 2). These countless holes 44 provide the buffer layer 40 with a function of absorbing gas. Further, the entire area of the film sensor 20 is bonded to the buffer layer 40 by the adhesive material 30. Therefore, in the buffer layer 40, at least the entire range 41 located between the switch operation surface 11 and the film sensor 20 is bound to the film sensor 20 by the adhesive material 30. Further, as shown in FIG. 1, the buffer layer 40 is formed on the inner surface of the housing 10 so as to have a larger area than the film sensor 20. Therefore, the film sensor 20 can expose the peripheral edge 43 in the atmosphere inside the housing 10 from between the film sensor 20 and the housing 10.

  According to the above configuration, as indicated by a plurality of arrows in FIG. 2, the gas generated from the housing 10 including the input unit 12 is in close contact with the input unit 12 by covering the inner surface of the housing 10. Flows into the buffer layer 40. Then, the gas stays in the infinite number of holes 44 formed in the buffer layer 40 or moves gradually through the infinite number of holes 44. In this way, the gas is released from the peripheral edge 43 (see FIG. 1) exposed to the atmosphere to the outside of the buffer layer 40 while being dispersed and diffused in the buffer layer 40.

  According to the present embodiment described so far, a situation in which the above-described gas is combined between the input unit 12 and the film sensor 20 and grows into a large bubble is avoided. Therefore, a change in the distance between the input unit 12 and the film sensor 20 due to the grown bubbles can be suppressed. As described above, the change with time in the capacitance generated between the finger 2 brought into contact with the switch operation surface 11 and the electrode 22 is reduced. Therefore, the sensitivity for detecting the contact operation of the finger 2 with the switch operation surface 11 can be maintained good over a long period of use of the electrostatic touch panel 1.

  In addition, in the configuration in which each component from the film sensor 20 to the input unit 12 can transmit light as in the present embodiment, the bubbles formed by combining the gases are transmitted through each of the above-described components 20, 30, 40, and 12. As a result, the light from the light source 60 that illuminates the switch operation surface 11 may cause spots. However, since the generation of bubbles is continuously suppressed by the function of the buffer layer 40 described above, the design of characters, images, and the like formed on the switch operation surface 11 is uneven over the long-term use of the electrostatic touch pad. It is illuminated by the reduced light. Therefore, in the electrostatic touch panel 1 in which the buffer layer 40 is formed, not only the change with time of the capacitance generated between the finger 2 and the film sensor 20 but also the deterioration with time of the design of the switch operation surface 11 can be reduced. .

  In addition, according to the present embodiment, the gas that has flowed into the buffer layer 40 is released to the outside, so that the function of the buffer layer 40 that allows the gas to flow in can be maintained over a long period of time. Thus, if the growth of gas into bubbles is continuously suppressed, the change with time in the capacitance between the finger 2 and the electrode 22 can be reduced with higher certainty.

  Furthermore, if it is the buffer layer 40 which forms the several void | hole 44 like this embodiment, the function which discharge | releases gas outside by transmitting an infinite number of void | holes 44 can be exhibited reliably. In addition, since the individual holes 44 are very small, a decrease in the capacitance generated between the electrode 22 and the finger 2 due to the formation of the buffer layer 40 can be slight. Thus, the above-described buffer layer 40 in which a plurality of minute holes 44 are formed is suitable for the configuration in which the gas generated from the housing 10 flows.

  In addition, according to the present embodiment, in the buffer layer 40, the entire range 41 located between the switch operation surface 11 and the film sensor 20 is bound to the film sensor 20 by the adhesive material 30. According to this adhesive material 30 suppressing gas permeation, a situation in which the gas once flowing into the buffer layer 40 leaks between the buffer layer 40 and the adhesive material 30 is avoided. By suppressing the growth of bubbles between the buffer layer 40 and the adhesive material 30 in this way, the effect of reducing the change with time of the electrostatic capacity is exhibited with higher certainty.

(Other embodiments)
As mentioned above, although one embodiment by the present invention was described, the present invention is not interpreted limited to the above-mentioned embodiment, and is applied to various embodiments and combinations within the range which does not deviate from the gist of the present invention. be able to.

  In the modification of the above embodiment, the film sensor, the adhesive material, the buffer layer, and the input unit are not configured to transmit light, and the light source is also omitted. In the modification with the above configuration, the design or the like provided on the switch operation surface is not illuminated by the light from the light source. However, even when the structure for forming the buffer layer is applied to such a modification, it is possible to exert an effect of suppressing the change in capacitance with time.

  In the modification of the above embodiment, the buffer layer is not colorless and transparent, but is colored while maintaining light transmission. With such a configuration, the emission color can be adjusted for the design of the switch operation surface illuminated by the light transmitted through the buffer layer. As described above, the buffer layer may have a function of decorating the design of the switch operation surface as well as the function of flowing in the gas generated from the input unit.

  In the modification of the above embodiment, the range of the buffer layer bound to the film sensor by the adhesive material is changed. For example, a part of the buffer layer located between the switch operation surface and the electrode may not be bonded to the adhesive material. However, it is desirable that the entire area of the film sensor is bound to the buffer layer by an adhesive material.

  In the above embodiment, the buffer layer 40 is a single-layer coating film by acrylic clear coating, and the gas generated from the input unit 12 is caused to flow into the plurality of minute holes 44. However, the configuration of the buffer layer may be changed as appropriate. For example, instead of the minute holes, a buffer layer that forms a plurality of minute grooves may cover the opposing surface of the input unit. Furthermore, the size of the holes may be changed as appropriate. In addition, the buffer layer may be formed by stacking a plurality of films. Moreover, the material of the housing | casing in which a buffer layer is provided is not limited to polycarbonate resin, You may change suitably. Note that the holes 44 shown in FIG. 2 are schematically enlarged, and the actual sizes of the holes are smaller and irregular than those shown in FIG. Furthermore, the actual holes are formed in an irregular arrangement.

  In the above embodiment, the peripheral edge 43 of the buffer layer 40 is formed outside the adhesive material and the film sensor and exposed to the atmosphere so that the gas flowing into the buffer layer 40 is released into the atmosphere. However, the entire buffer layer may be covered with the adhesive material and the film sensor, and the gas flowing into the buffer layer may be difficult to be released into the atmosphere.

  In the above embodiment, the finger 2 is assumed to be an object corresponding to the “input operation body” recited in the claims, but the “input operation body” is not limited to the finger 2 and may be a touch pen or an operator. It may be a part other than the fingers. Alternatively, a finger with a glove containing a conductive material may be assumed as the “input operation body”.

  In the said embodiment, the example which applied this invention to the electrostatic touch panel 1 which operates the air conditioner mounted in the vehicle was demonstrated. However, the present invention is used not only for such vehicles but also for various transportation equipment and various information terminals, and the presence / absence of input is determined based on the change in capacitance generated between the electrode and the fingers. Applicable to all types of electrostatic touch panels.

DESCRIPTION OF SYMBOLS 1 Electrostatic touch panel, 2 fingers (input operation body), 10 housing | casing, 11 Switch operation surface (contact surface), 12 Input part, 12a Opposing surface, 13 Liquid crystal display part, 20 Film sensor (electrode member), 30 Adhesive material (Binder), 40 buffer layer, 44 holes, 50 detection circuit, 60 light source

Claims (4)

An input unit (12) having a contact surface (11) with which the input operating body (2) contacts;
An electrode member (20) whose capacitance changes according to the contact of the input operation body with the contact surface;
A gas inflow layer (40) that covers a facing surface (12a) of the input portion facing the electrode member and into which a gas generated from the input portion flows;
Wherein with gas inlet layer and binder for binding and said electrode member (30), a
The gas inlet layer, an electrostatic touch panel of the gas flowing from the input unit, characterized that you discharged to the outside from between the input portion and the electrode member. The electrostatic touch panel according to claim 1 , wherein a plurality of holes (44) through which the gas flows are formed. The binder material, the whole range (41) located between said contact surface and said electrode member of said gas inlet layer, to claim 1 or 2, characterized in that the binder and the electrode member The described electrostatic touch panel. A light source (60) that is located on the opposite side of the input part across the electrode member and emits light toward the input part;
Said electrode member, said binder, said gas inlet layer, and wherein the input unit, the electrostatic touch panel according to any one of claims 1 to 3, characterized in that transmits light from the light source.

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