JP2016024581A - Capacitive input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitive input device capable of solving convenient problems that, since transparent wiring has a limitation in freedom of wiring depending on the layout of transparent electrodes connected thereto, some transparent wirings may not have satisfactorily low resistance value resulting in a decrease of the sensitivity of transparent electrodes.SOLUTION: Conductive auxiliary wirings 6A, 6B, 6C and 6D are formed parallel to at least a part of transparent wirings 4A, 4B, 4C and 4D each of which is connected to transparent electrodes 3A, 3B, 3C and 3D respectively, which are formed on a transparent base plate 1 having a light transmission area 10. The auxiliary wirings are formed in the light transmission area 10 together with the transparent electrodes and transparent wirings.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a capacitance-type input device in which a transparent electrode for detecting a change in capacitance is provided on a transparent substrate.

  Navigation appliances such as rice cookers and refrigerators, and navigation, audio, and air conditioning equipment that are equipped with switches on vehicle instrument panels, etc., have capacitance input devices that detect changes in capacitance and perform input operations. It is used.

  A capacitance type input device is usually made of glass or acrylic via a transparent optical adhesive (OCA) to a capacitance type input device in which a transparent electrode and wiring for detecting a change in capacitance are formed on a transparent substrate. It is constructed by laminating transparent operation panels. The capacitance-type input device can perform an input operation for switching operation or display corresponding to the display unit by operating the operation panel with a finger or the like while viewing the display unit on the back surface displayed through the operation panel. It is like that.

  By the way, the capacitance type input device is controlled by a control circuit provided in the electronic apparatus main body. In the capacitive input device, a plurality of transparent electrodes are formed on a transparent substrate in accordance with a position where an input operation can be performed. In the capacitive input device, a plurality of wirings connected to the control circuit are formed on the transparent substrate, and the plurality of wirings are respectively connected to the corresponding transparent electrodes.

  The operation panel of the capacitive input device usually has a display region that transmits light from the display device on the back surface, and a non-light-transmitting non-display region at the outer periphery of the display region. The display area is provided at a position corresponding to a plurality of transparent electrodes of the capacitive input device, and a display unit provided corresponding to each transparent electrode can be viewed.

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

JP 2012-178149 A

  By the way, a transparent electrode is arrange | positioned based on the display part of an electrostatic capacitance type input device, and a part of transparent electrode and wiring are arrange | positioned in the display area of an operation panel. Therefore, a relay wiring is required to relay the transparent electrode and the wiring arranged in the non-display area of the operation panel, and the transparent wiring is used as the relay wiring.

  In the capacitance type input device, transparency is important for the transparent electrode and the transparent wiring in order to transmit the display and illumination light on the back surface of the transparent substrate on which the transparent electrode and the transparent wiring are formed. The transparent electrode and the transparent wiring are considered to satisfy main required characteristics such as electric resistance and transparency, and transparent conductive films such as ITO (Indium Tin Oxide), fluorine-doped tin oxide, polythiophene, and polyaniline. It is formed by.

  In a capacitance-type input device, a plurality of transparent electrodes and a plurality of transparent wirings are usually provided, and each transparent wiring is routed so as to avoid other transparent electrodes depending on the arrangement of the transparent electrodes to be connected. It is formed. Therefore, each transparent wiring has a different length, and the degree of freedom of width and thickness is also limited. Therefore, there is a problem that the sensitivity of the transparent electrode deteriorates because the transparent wiring cannot have a sufficiently low resistance value. .

  The capacitance-type input device of the prior document shown in Patent Document 1 includes a wiring connected to a transparent electrode, a first layer made of the same material as that of the transparent electrode, and a material having a lower electrical resistance than the material of the first layer The second layer made of is laminated. Thereby, the electrical resistance of wiring is made lower than the electrical resistance of a transparent electrode.

  Moreover, the electrostatic capacitance type input device of the prior art is formed by laminating an auxiliary electrode made of a material having a smaller electric resistance than the transparent electrode on one side of the connection side connected to the wiring of the transparent electrode.

  However, the electrostatic capacitance type input device of the prior document has a configuration in which the transparent electrode and the wiring are directly connected without being relayed by the relay wiring, and the wiring and the auxiliary electrode are provided in the non-display area of the panel surface. Is assumed. In other words, since the capacitance type input device of the prior art does not use the wiring and the auxiliary electrode as a transparent material, the entire surface of the transparent electrode and the relay wiring that relays the transparent electrode and the connection wiring are arranged in the display area of the operation panel. Not available when used.

  The present invention reduces the resistance between the transparent electrode and the connection wiring by reducing the resistance value between the transparent electrode and the connection wiring even when the entire transparent electrode and the transparent wiring that relays the transparent electrode and the connection wiring are arranged in the display area of the operation panel. It is an object of the present invention to provide a capacitance type input device in which a decrease is suppressed.

  In order to achieve the above object, a capacitive input device according to the present invention includes a transparent substrate having a light transmission region, a transparent electrode provided on the transparent substrate, a transparent wiring connected to the transparent electrode, and a transparent substrate. Each of the wirings includes a connection wiring and a conductive auxiliary wiring provided in parallel with at least a part of the transparent wiring. The transparent electrode, the transparent wiring, and the auxiliary wiring are provided in a light transmission region on the transparent substrate.

  As described above, according to the present invention, since the auxiliary wiring is provided in parallel to at least a part of the transparent wiring in the light-transmitting area of the transparent substrate, the degree of freedom of arrangement of the transparent electrode is high, and the display area of the operation panel is provided. In addition, it is possible to provide a capacitance type input device in which the deterioration of the sensitivity of the transparent electrode is suppressed while avoiding the deterioration of the visibility.

1 is a plan view of a capacitive input device according to a first embodiment of the present invention. Sectional drawing of the capacitance-type input device by the 1st Embodiment of this invention The top view which shows the electrostatic capacitance type input device of the 2nd Embodiment of this invention Sectional drawing which shows the electrostatic capacitance type input device of the 3rd Embodiment of this invention 1 is an exploded perspective view of a capacitive input device using a capacitive input device according to first to third embodiments of the present invention.

  Embodiments of the present invention will be described below with reference to FIGS.

(First embodiment)
FIG. 1 is a plan view of a capacitive input device according to a first embodiment of the present invention, and FIG. 2 is a sectional view thereof.

  The capacitance-type input device 100 according to the first embodiment of the present invention has a circuit wiring pattern 2 formed on a transparent substrate 1 formed of a transparent substrate such as polycarbonate (PC) or polyethylene terephthalate (PET). It is configured.

  The circuit wiring pattern 2 includes a plurality of transparent electrodes 3A, 3B, 3C, and 3D, a plurality of transparent wirings 4A, 4B, 4C, and 4D that are connected to the plurality of transparent electrodes 3A, 3B, 3C, and 3D, respectively. A plurality of connection wires 5A, 5B, 5C, and 5D connected to the transparent wires 4A, 4B, 4C, and 4D are provided.

  The transparent wirings 4A, 4B, 4C, and 4D are provided with conductive auxiliary wirings 6A, 6B, 6C, and 6D, which are stacked. The auxiliary wirings 6A, 6B, 6C, 6D are preferably transparent.

  The transparent electrodes 3A, 3B, 3C, and 3D and the transparent wirings 4A, 4B, 4C, and 4D are formed of a transparent conductive film such as ITO (tin-doped indium oxide), fluorine-doped tin oxide, polythiophene, or polyaniline.

  The connection wirings 5A, 5B, 5C, and 5D are formed of a metal wiring of a conductive metal material that is composed of silver, copper, gold, aluminum, an alloy thereof, or a paste mainly containing these metals.

  The auxiliary wirings 6A, 6B, 6C, 6D preferably have an electric resistance value smaller than that of the transparent wirings 4A, 4B, 4C, 4D. Auxiliary wiring 6A, 6B, 6C, 6D can be comprised by a metal fine wire etc., for example.

  At this time, the connection wirings 5A, 5B, 5C, and 5D and the auxiliary wirings 6A, 6B, 6C, and 6D are usually made of the same material, but may be made of different materials.

  A region where the transparent electrodes 3A, 3B, 3C, 3D and the transparent wirings 4A, 4B, 4C, 4D of the transparent substrate 1 are formed is a light transmission region 10. That is, the light transmission region 10 is provided inside the region where the connection wirings 5A, 5B, 5C, and 5D are formed. Therefore, the light transmission region 10 can transmit light and illumination light from the display device on the back surface of the transparent substrate 1.

  The connection wirings 5A, 5B, 5C, and 5D are connected to a control circuit (not shown) that controls the capacitive input device 100. Therefore, the transparent electrodes 3A, 3B, 3C, and 3D are connected to connection wirings 5A, 5B, 5C, and 5D using the transparent wirings 4A, 4B, 4C, and 4D as relay wirings, and are connected to a control circuit (not shown). .

  The auxiliary wirings 6A, 6B, 6C, and 6D are stacked on the corresponding transparent wirings 4A, 4B, 4C, and 4D, respectively, and are connected in parallel to the transparent wirings 4A, 4B, 4C, and 4D, respectively. The auxiliary wirings 6A, 6B, 6C, and 6D are formed linearly and continuously from the connection wirings 5A, 5B, 5C, and 5D to the vicinity of the tips of the transparent electrodes 3A, 3B, 3C, and 3D, respectively. Note that the auxiliary wirings 6A, 6B, 6C, and 6D do not necessarily have to be straight lines, and may be formed entirely or partially curved.

  The auxiliary wirings 6A, 6B, 6C, 6D having an electric resistance smaller than that of the transparent wirings 4A, 4B, 4C, 4D thus configured are connected in parallel to the corresponding transparent wirings 4A, 4B, 4C, 4D, respectively. ing. Therefore, the resistance values between the connection wirings 5A, 5B, 5C, and 5D and the corresponding transparent electrodes 3A, 3B, 3C, and 3D are smaller than when the auxiliary wirings 6A, 6B, 6C, and 6D are not formed.

  The thin metal wires constituting the auxiliary wirings 6A, 6B, 6C, and 6D are each formed with a thickness of 10 μm or less, and have a thickness that is not substantially visible even if opaque. The fine metal wires constituting the auxiliary wirings 6A, 6B, 6C, 6D are formed of a conductive metal material having a smaller resistance value per unit volume than the transparent conductive film constituting the transparent wirings 4A, 4B, 4C, 4D. ing. Therefore, even if the thin metal wires constituting the auxiliary wirings 6A, 6B, 6C, and 6D have a thickness that is not visually recognized, the connection wirings 5A, 5B, 5C, and 5D, and the corresponding transparent electrodes 3A, 3B, 3C, and 3D, respectively. The resistance value between them can be made sufficiently small.

  When pursuing the difficulty of visually recognizing the fine metal wires as the auxiliary wirings 6A, 6B, 6C, and 6D, the thickness of the fine metal wires is preferably 5 μm or less. However, the thickness of the fine metal wires is determined in consideration of the resistance value. Is done.

  When a thin metal wire having a thickness of 10 μm is provided as auxiliary wiring 6A, 6B, 6C, 6D, as shown in Table 1, in each of the three samples, the connection point A with the connection wiring 5A of the transparent wiring 4A, and the transparent electrode The resistance value at the position B farthest from the transparent wiring 4A of 3A and the resistance value at the connection point C of the transparent wiring 4B with the connection wiring 5B and the position D farthest from the transparent wiring 4B of the transparent electrode 3B were measured. However, it has been confirmed that each resistance value is 14.1 to 26.7% smaller than that in the case where the auxiliary wirings 6A and 6B are not formed.

接続配線５Ｂから透明電極３Ｂまでの抵抗値が小さくなると、接続配線５Ｂから透明電極３Ｂまでの距離による抵抗値の変化が小さくなる。そのため、複数の透明電極において、補助配線６Ａ、６Ｂ、６Ｃ、６Ｄを設けない場合に比べて接続配線５Ｂから透明電極３Ｂまでの距離による抵抗値のばらつきが小さくなり、各透明電極における感度変化が小さくなる。

When the resistance value from the connection wiring 5B to the transparent electrode 3B decreases, the change in resistance value due to the distance from the connection wiring 5B to the transparent electrode 3B decreases. For this reason, in the plurality of transparent electrodes, the variation in resistance value due to the distance from the connection wiring 5B to the transparent electrode 3B is smaller than when the auxiliary wirings 6A, 6B, 6C, and 6D are not provided, and the sensitivity change in each transparent electrode is reduced. Get smaller.

  In the present embodiment, the auxiliary wirings 6A, 6B, 6C, and 6D are formed so as to enter the transparent electrodes 3A, 3B, 3C, and 3D, respectively. Therefore, the variation in potential within the transparent electrodes 3A, 3B, 3C, and 3D, that is, the change in resistance value is small. Thereby, the sensitivity change in the area | region of transparent electrode 3A, 3B, 3C, 3D becomes small compared with the case where auxiliary wiring 6A, 6B, 6C, 6D is not provided.

(Second Embodiment)
FIG. 3 is a plan view showing a capacitive input device 200 according to the second embodiment of the present invention.

  The capacitance-type input device 200 is different from the first embodiment in the configuration of the circuit wiring pattern formed on the transparent substrate 11.

  The transparent electrodes 13A, 13B, 13C, and 13D are connected via the transparent wirings 14A, 14B, 14C, and 14D corresponding to the connection wirings 15A, 15B, 15C, and 15D, respectively.

  Auxiliary wirings 16A and 16B are provided on the transparent wirings 14A and 14B. As in the first embodiment, the auxiliary wirings 16A and 16B are formed of, for example, conductive fine metal wires each having a thickness of 10 μm or less, and are stacked on the transparent wirings 14A and 14B and connected in parallel. . Therefore, the resistance value between the connection wirings 15A and 15B and the corresponding transparent electrodes 13A and 13B is smaller than that when the auxiliary wirings 16A and 16B are not formed. As a result, the sensitivity change in the transparent electrodes 13A and 13B is reduced.

  The auxiliary wiring 16A is formed so as to surround the periphery of the transparent electrode 13A. Therefore, the potential difference is suppressed in the region of the transparent electrode 13A, and the sensitivity change can be reduced.

  The auxiliary wiring 16B extends from the connection wiring 15B to the farthest side from the connection wiring 15B of the transparent electrode 13B, and is formed in an L shape along that side. Therefore, in the region of the transparent electrode 13B, the potential difference is suppressed compared to the case where the auxiliary wiring is formed in a straight line, and the sensitivity change can be reduced.

  Thus, the auxiliary wirings 16A and 16B have a degree of freedom in form.

  No auxiliary wiring is provided in the transparent wirings 14C and 14D connected to the transparent electrodes 13C and 13D. The lengths of the transparent wirings 14C and 14D are significantly shorter than the lengths of the transparent wirings 14A and 14B, and are shorter than the lengths of the transparent electrodes 13C and 13D. For this reason, the resistance value of the transparent wirings 14C and 14D has little influence on the sensitivity change in the transparent electrodes 13C and 13D, so that the auxiliary wiring can be omitted.

  Specifically, when the electrical resistance value of the transparent wiring is 1 kΩ or more, the sensor sensitivity of the transparent electrode is significantly reduced. Therefore, it is desirable that the auxiliary electrode be provided in parallel with at least a part of the transparent wiring having an electric resistance value of 1 kΩ or more.

  As described above, the auxiliary wiring is provided so as to be connected in parallel to the transparent wiring as necessary, and need not be provided for all the transparent wiring.

(Third embodiment)
FIG. 4 is a cross-sectional view showing a capacitive input device 300 according to the third embodiment.

  The capacitive input device 300 is different from the first embodiment in the stacking order of members constituting the circuit wiring pattern 22 formed on the transparent substrate 21.

  The capacitive input device 300 is formed by forming an auxiliary wiring 26 on the transparent substrate 21 on which the connection wiring 25 is formed, and laminating the transparent wiring 24 and the transparent electrode 23 on the auxiliary wiring 26. The transparent wiring 24 and the transparent electrode 23 are provided so as to cover the auxiliary wiring 26 due to its flexibility.

  The transparent wiring 24 and the transparent electrode 23 are formed on the transparent substrate 21 by printing or applying a transparent conductive film. The positions where the transparent wiring 24 and the transparent electrode 23 are formed are determined with reference to the auxiliary wiring 26.

  Next, an example of use when a capacitive input device is configured using the above-described capacitive input device will be described.

  FIG. 5 is an exploded perspective view of a capacitive input device using the capacitive input device according to the first to third embodiments of the present invention.

  The capacitance type input device shown in the figure is configured by laminating a cover lens 32 made of a transparent material made of glass or acrylic with an adhesive layer 31 interposed in a capacitance type input device 30.

  The pressure-sensitive adhesive layer 31 is formed of a transparent optical pressure-sensitive adhesive (OCA: Optical Clear Adhesive) mainly composed of an acrylic acid polymer, a silicon-based polymer, or a mixture thereof.

  The capacitance type input device configured as described above is an operation panel having the cover lens 32 as an operation surface. The display region 33 transmits light from the display device on the back to the cover lens 32 and the outer periphery of the display region. A non-display area 34 that does not transmit light is provided at the periphery. A plurality of transparent electrodes are formed on the transparent substrate of the capacitive input device 30 according to the position where the input operation can be performed. The plurality of transparent electrodes are formed in the light transmission region 35 of the transparent substrate. The display region 33 is provided at a position opposite to the light transmission region 35 and the non-display region 34 is provided at a position opposite to the light non-transmission region 36. It has been.

  The surface of the capacitive input device 30 on which the circuit wiring pattern of the transparent substrate is formed is disposed on the adhesive layer 31 side. On the back surface of the capacitive input device 30 which is the back surface side of the circuit wiring pattern surface of the transparent substrate, a display device 38 such as a liquid crystal display device or illumination such as an LED is disposed via an adhesive layer 37 such as OCA. Is done. Therefore, the capacitive input device operates the operation surface on the surface of the cover lens 32 while looking at the display unit on the back surface displayed through the display area 33.

  When the operation surface on the surface of the cover lens 32 is operated with a finger or the like, the parasitic capacitances in the cover lens 32 and the adhesive layer 31 are connected in series from the transparent electrode corresponding to the operation position of the capacitance type input device 30. A signal corresponding to the combined capacity is obtained. Therefore, a change in capacitance is detected by the transparent electrode corresponding to the display unit displayed through the display area 33, and operation switching and display switching corresponding to the display unit can be performed.

  The embodiment described above is for facilitating understanding of the present invention, and is not intended to limit the present invention. The auxiliary wirings 6A, 6B, 6C, 6D, 16A, 16B, and 26 do not need to be in a straight line, and may be provided in parallel by avoiding transparent wiring, whether curved or zigzag. Further, the auxiliary wiring does not have to be placed on the transparent wirings 4A, 4B, 4C, 4D, 14A, 14B, 14C, 14D, and 24, and may be provided in parallel to be separated from the transparent wiring. .

  The auxiliary wiring may be formed of a transparent conductive film or carbon having a smaller electric resistance than that of the transparent wiring.

  The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention.

  The capacitance-type input device according to the present invention is suitable for use in a capacitance-type input device that detects an input operation of an electronic device based on a change in capacitance.

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Circuit wiring pattern 3A, 3B, 3C, 3D Transparent electrode 4A, 4B, 4C, 4D Transparent wiring 5A, 5B, 5C, 5D Connection wiring 6A, 6B, 6C, 6D Auxiliary wiring 10 Light transmission area 11 Transparent substrate 13A, 13B, 13C, 13D Transparent electrodes 14A, 14B, 14C, 14D Transparent wiring 15A, 15B, 15C, 15D Connection wiring 16A, 16B Auxiliary wiring 21 Transparent substrate 22 Circuit wiring pattern 23 Transparent electrode 24 Transparent wiring 25 Connection wiring 26 Auxiliary Wiring 30, 100, 200, 300 Capacitive input device 31, 37 Adhesive layer 32 Cover lens 35 Light transmission region

Claims (8)

A transparent substrate having a light transmission region;
A transparent electrode provided on the transparent substrate;
Transparent wiring connected to each of the transparent electrodes;
A connection wiring connected to each of the transparent wirings;
A conductive auxiliary wiring provided in parallel with at least a part of the transparent wiring,
The capacitive input device, wherein the transparent electrode, the transparent wiring, and the auxiliary wiring are provided in the light transmission region on the transparent substrate.   The capacitance-type input device according to claim 1, wherein an electric resistance value of the auxiliary wiring is smaller than an electric resistance value of the transparent wiring.   The capacitive input device according to claim 1, wherein the auxiliary wiring is a thin metal wire.   The capacitive input device according to claim 3, wherein the thin metal wires are stacked on the transparent wiring.   The capacitive input device according to claim 3, wherein the thin metal wire is formed so as to penetrate into the transparent electrode. The capacitance type input device according to claim 3, wherein the thin metal wire has a thickness of 10 μm or less.   The capacitance type input device according to claim 3, wherein the thin metal wire has a thickness of 5 μm or less. A plurality of the transparent electrode, the transparent wiring and the connection wiring are provided,
3. The capacitive input device according to claim 1, wherein the auxiliary wiring is provided at least partially in parallel with a transparent wiring having a resistance value of 1 kΩ or more among the transparent wiring. 4.

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