JP2017054238A - Projection capacitive touch sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a touch sensor.SOLUTION: A touch sensor 1 comprises a transparent first substrate 2 to be touch-operated, a transparent second substrate 3 spaced from the first substrate 2, a first electrode 4 fixed to the first substrate 2, and a second electrode 5 fixed to the second substrate 3. The first substrate 2 comprises a flexible glass substrate. The first electrode 4 comprises a thin metal wire.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a projected capacitive touch sensor used for a touch panel.

  Conventionally, touch panels have been used in bank ATMs, game center game machines, and ticket machines such as trains and buses. By mounting the touch panel on the display device, it is possible to intuitively operate the device through information from the information displayed on the display device. Therefore, there is an advantage that the operation of the device mounted with the touch panel becomes easy. .

  In addition, since the touch panel allows the input device to be mounted in the display device, it is not necessary to provide a separate input device, and the entire device can be downsized. Accordingly, touch panels are also suitably used in mobile phones, smartphones, portable game devices, tablet PCs, and notebook PCs that require miniaturization.

  Various methods such as resistive film method, surface acoustic wave method, infrared method, electromagnetic induction method, capacitance method, etc. are adopted for the touch panel. ), A projected capacitive touch panel is employed in smartphones, tablet PCs, and the like.

  As a touch sensor used for a projected capacitive touch panel, as disclosed in Patent Document 1, a relatively hard and transparent first substrate (substrate 105) is opposed to the first substrate. And a relatively flexible and transparent second substrate (substrate 115), a transparent first electrode (patterned capacitance detection electrode 110) provided on one surface of the first substrate, and a second substrate There is one provided with a transparent second electrode (common plate electrode 120) provided on one surface. This touch sensor can detect a change in capacitance by touching (pressing) the second substrate with a finger or the like, and can detect the pressed position.

  In this touch sensor, the first substrate and the second substrate are made of glass or a polymer material, and the first electrode and the second electrode are made of a transparent material, for example, ITO (indium tin oxide). (See paragraph 0018 of the same document).

Special table 2013-508887 gazette

  In the conventional touch sensor, since the second electrode on the second substrate to be touched is made of ITO, the second electrode is quickly plasticized while the second substrate is repeatedly operated. Wire breakage due to deformation and fatigue is likely to occur, and there is still a problem in durability.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a projected capacitive touch sensor with improved durability.

  The present invention is for solving the above-described problems, and includes a transparent first substrate that is touch-operated, a transparent second substrate that is spaced apart from the first substrate, and the first In the projected capacitive touch sensor comprising a first electrode fixed to one substrate and a second electrode fixed to the second substrate, the first substrate is flexible. The first electrode is formed of a thin metal wire.

  According to such a configuration, since the first substrate to be touched is formed by the glass substrate, the strength can be increased as compared with the case where the first substrate is configured by the resin film. The durability of the projected capacitive touch sensor (hereinafter simply referred to as “touch sensor”) can be improved. Furthermore, if the first electrode on the first substrate to be touched is made of a thin metal wire, its strength can be increased compared to the case of being made of ITO, thereby further enhancing the durability of the touch sensor. Can be improved.

  In the touch sensor according to the present invention, a configuration having a space between the first substrate and the second substrate can be employed. As a result, even when the first substrate is deformed by a touch operation, contact with the second substrate is avoided, and wear and damage of the first substrate are effectively prevented.

  In the touch sensor according to the present invention, a configuration in which a gel substance is interposed between the first substrate and the second substrate can be employed. By using a gel material having a refractive index close to that of each substrate, the visibility of the touch sensor can be greatly improved.

    In the touch sensor according to the present invention, a configuration in which an elastically deformable resin layer is provided between the first substrate and the second substrate can be employed. If this resin layer is configured to be elastically deformable, a function for assisting the first substrate deformed by the touch operation to return to its original shape can be exhibited, and a touch sensor with good operation responsiveness can be realized.

  In addition, the touch sensor according to the present invention preferably includes a resin film that covers the first electrode. Accordingly, the first electrode is protected and, when an impact is applied to the first substrate, this resin film suppresses the vibration of the first substrate, thereby preventing the touch sensor from malfunctioning. In addition, damage to the first substrate can be prevented.

  The first substrate preferably has a thickness of 20 μm to 500 μm. As a result, the first substrate can have a strength that can withstand a touch operation, and can be flexible enough to realize the touch operation.

  In the touch sensor according to the present invention, the first substrate may have an operation surface on which a touch operation is performed, and the operation surface may have a protrusion that indicates a reference position for the touch operation. Thus, the operator can tactilely recognize the reference position of the operation surface by touching the protrusion with a finger. Thereby, a simple operation by a blind touch becomes possible.

  ADVANTAGE OF THE INVENTION According to this invention, durability of a touch sensor can be improved.

FIG. 1 is a cross-sectional view showing a first embodiment of a touch sensor. FIG. 2 is a cross-sectional view of the touch sensor in the same embodiment. FIG. 3 is a cross-sectional view showing a second embodiment of the touch sensor. FIG. 4 is a cross-sectional view showing a third embodiment of the touch sensor. FIG. 5 is a cross-sectional view showing a fourth embodiment of the touch sensor.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of a touch sensor according to the present invention.

  As shown in FIG. 1, the touch sensor 1 includes a transparent first substrate 2 (input-side substrate) that is touch-operated (pressed) and a transparent first substrate that is disposed opposite to the first substrate 2. The second substrate 3 (opposite substrate), the first electrode 4 fixed to the first substrate 2, the second electrode 5 fixed to the second substrate 3, the first substrate 2 and the first substrate 2 And a sealing member 6 (fulcrum sealing member) for connecting the two substrates 3 to each other.

  The first substrate 2 is a transparent glass substrate configured in a flat plate shape. Although the 1st board | substrate 2 is comprised by the rectangular shape, it is not limited to this shape. The first substrate 2 is configured as an elastic body that has flexibility and can be deformed by a touch operation. The first substrate 2 is not limited to a flat plate, but may have a curved surface shape that does not hinder the touch operation. As the material of the first substrate 2, silicate glass, silica glass, borosilicate glass, soda lime glass, aluminosilicate glass, non-alkali glass and the like are preferably used. The alkali-free glass is a glass that does not substantially contain an alkali component (alkali metal oxide), and specifically, a glass having a weight ratio of the alkali component of 1000 ppm or less. . As the first substrate 2, a thin glass “G-leaf” (registered trademark) manufactured by Nippon Electric Glass Co., Ltd. can be used particularly preferably.

  The thickness of the first substrate 2 is preferably 20 μm or more and 500 μm or less, but is not limited thereto. For example, when the size of one side of the first substrate 2 is as small as 50 mm or more and 100 mm or less, an ultrathin plate glass having a thickness of 20 μm or more and 200 μm or less can be used for the first substrate 2. Moreover, when the dimension of the one side in the 1st board | substrate 2 exceeds 100 mm, in order to ensure the rigidity of the 1st board | substrate 2, the thin glass whose thickness is 100 micrometers or more and 500 micrometers or less can be used. Accordingly, the first substrate 2 is elastically deformed by a touch operation (input operation), and can be automatically restored to an initial shape when the operation is completed. In the present embodiment, the first substrate 2 has a rectangular shape with a length of 130 mm and a width of 70 mm, for example, but is not limited thereto.

  The first substrate 2 can be manufactured by using a known float method, roll-out method, slot down draw method, redraw method or the like, but is preferably formed by an overflow down draw method. Thereby, a glass substrate with a thickness of 300 μm or less can be manufactured in large quantities and at low cost. The glass substrate produced by the overflow down draw method does not require adjustment of the thickness of the glass substrate by polishing, grinding, chemical etching or the like. In addition, the overflow down draw method is a molding method in which both sides of the glass plate do not come into contact with the molded member at the time of molding, and both sides (translucent surface) of the obtained glass plate are fired surfaces and are not polished. Even with this, a glass substrate having a high surface quality can be obtained.

  As shown in FIG. 1, the 1st board | substrate 2 has the 1st surface 2a to which the 1st electrode 4 is fixed, and the 2nd surface 2b located in the other side of this 1st surface 2a. . The first surface 2 a supports the first electrode 4 in a state of facing the second substrate 3. The second surface 2b functions as an operation surface used for a touch operation.

  The second substrate 3 can be made of the same material and the same manufacturing method as the first substrate 2. In addition to being configured as a glass substrate, the second substrate 3 may be configured with a resin film. The thickness of the second substrate 3 is preferably 100 μm or more and 700 μm or less, but is not limited thereto. In the present embodiment, the thickness of the second substrate 3 is 500 μm, but is not limited to this, and is appropriately set according to the application, size, shape, and the like of the touch sensor 1. As the second substrate 3, for example, thin glass “OA-10G” made of non-alkali glass manufactured by Nippon Electric Glass Co., Ltd. can be suitably used.

  The second substrate 3 has a first surface 3a to which the second electrode 5 is fixed, and a second surface 3b located on the opposite side of the first surface 3a. The first surface 3 a is disposed to face the first surface 2 a of the first substrate 2. The separation distance between the first surface 3a and the first surface 2a of the first substrate 2 is preferably 0.1 mm or more and 5 mm or less, but is not limited thereto. By setting such a separation distance, when the first substrate 2 is deformed by a touch operation, contact with the second substrate 3 is avoided, and a situation such as breakage or wear can be prevented.

  Further, the second substrate 3 is disposed away from the first substrate 2, so that a space 7 (cavity) is formed therebetween. In the present embodiment, the space 7 is filled with air. The second surface 3b of the second substrate 3 can be fixed to a display device such as a thin display (not shown). When the second substrate 3 is made of thin glass, the second electrode 5 may be fixed to the second surface 3b.

  The first electrode 4 and the second electrode 5 are opaque and are both composed of a plurality of fine metal wires. The first electrode 4 and the second electrode 5 cross each other and present a lattice structure, that is, a mesh metal structure, when they are projected in plan view. In the present embodiment, the electrodes 2 and 3 are configured to be linear and intersect with each other. However, the present invention is not limited to this, and the electrodes 2 and 3 may be individually configured in a grid pattern. When the second surface 2b of the first substrate 2 is touch-operated, the touch sensor 1 can specify the position by plane coordinates including the X axis and the Y axis. In this case, one of the first electrode 4 and the second electrode 5 is an X electrode corresponding to the X axis, and the other is a Y electrode corresponding to the Y axis.

  The 1st electrode 4 and the 2nd electrode 5 as a metal fine wire may be comprised by metal materials (electrically conductive material), such as gold | metal | money, silver, copper, for example. The line width of the fine metal wire is preferably 2.5 μm or more and 15 μm or less, but is not limited thereto. Moreover, although it is preferable that the space | interval of this metal fine wire shall be 1 micrometer or more and 1000 micrometers or less, it is not limited to this. In the present embodiment, the first electrode 4 can be constituted by, for example, a straight copper thin wire having a line width of 3 μm and a distance of 300 μm. The second electrode 5 is composed of a straight copper thin wire having a line width of 3 μm and a distance of 300 μm, and is arranged so as to be orthogonal to the first electrode 4 in plan view.

  In order to form the first electrode 4 on the first substrate 2, first, a copper foil or a copper film is formed on the first surface 2a of the first substrate 2, and a photoresist film is formed on the copper foil. Then, the photoresist film is exposed and developed to form a resist pattern. Thereafter, the portion of the copper foil exposed from the resist pattern is etched, whereby the first electrode 4 having a predetermined electrode pattern is formed on the first surface 2a of the first substrate 2. The first electrode 4 is not limited to the above method, and can be formed on the first substrate 2 by various known methods. The second electrode 5 is formed on the first surface 3 a of the second substrate 3 by the same method as the first electrode 4.

  As shown in FIGS. 1 and 2, the first electrode 4 is covered with a transparent resin film 8. The resin film 8 has an insulating property and a function of suppressing the vibration of the first substrate 2. The resin film 8 can be formed by sticking a highly transparent base material such as PVC, PET, PP or the like to the first surface 2a of the first substrate 2 with an adhesive. The resin film 8 can be formed by directly applying a resin material to the first surface 2a. The thickness of the resin film 8 is preferably 25 μm or more and 100 μm or less, but is not limited thereto. In this embodiment, the resin film 8 is formed by applying an acrylic resin having a thickness of 20 μm to the first surface 2a. By forming the resin film 8 on the first substrate 2, the first electrode 4 can be protected.

  The seal member 6 seals the first substrate 2 and the second substrate 3 in a state where they are separated from each other. The sealing member 6 seals the four sides of the first substrate 2 and the second substrate 3, but is not limited to this. For example, the sealing member 6 may connect two sides of the first substrate 2 and the second substrate 3. The sealing member 6 seals each of the substrates 2 and 3 at a portion outside the sensor area constituted by the first electrode 4 and the second electrode 5. The seal member 6 can function as a fulcrum when the first substrate 2 is deformed by a touch operation.

  As the material of the seal member 6, a resin that can be elastically deformed with respect to the deformation of the first substrate 2 is preferable. For example, a silicone rubber seal material or a butyl rubber seal material is preferably used. In this embodiment, an acrylic adhesive is used as the seal member 6, and the first substrate 2 and the second substrate 3 are bonded together. For example, a glass spacer having a diameter of 0.3 mm is mixed in the seal member 6. As this glass spacer, “Microrod” (registered trademark) manufactured by Nippon Electric Glass Co., Ltd. can be suitably used.

  A touch panel is configured by fixing the second substrate 3 of the touch sensor 1 having the above configuration on the screen of a display device such as a thin display. The touch panel can input an operation instruction corresponding to the display information as a signal by a touch operation on the touch sensor 1.

  Hereinafter, the usage method and operation of the touch sensor 1 according to the above configuration will be described.

  The touch sensor 1 according to the present embodiment can detect the contact position (contact point) when the operator's finger 9 is brought into contact with the second surface 2b (operation surface) of the first substrate 2. Specifically, as shown in FIG. 1, the first electrode 4 and the second electrode 5 are arranged so as to intersect with each other, so that the static electrode formed by the first electrode 4 and the second electrode 5 is arranged. The capacitance is the capacitance formed at the intersection of the first electrode 4 and the second electrode 5 and the capacitance formed by the protruding effect of electric lines of force called fringe field in the peripheral portion other than the intersection. Sum of capacity. By bringing the finger 9 into contact with the second surface 2 b of the first substrate 2, a part of the electric lines of force called a fringe field are terminated at the finger 9, and as a result, the first electrode 4 And the capacity between the second electrode 5 decreases. The touch sensor 1 can accurately specify the coordinate position of the contact point of the finger 9 on the XY plane by detecting this decrease in capacitance using a separately provided circuit. Since the touch sensor 1 is a projection type capacitive sensor, a plurality of contact points (multi-touch) can be detected simultaneously.

  When the touch sensor 1 according to the present embodiment brings the finger 9 into contact with the second surface 2b of the first substrate 2 and further presses it as shown in FIG. 2 to deform the first substrate 2, The amount of deformation (pressing force) can also be detected. That is, when the first substrate 2 is deformed, the distance between the first substrate 2 and the second substrate 3 is locally reduced. As a result, the capacitance between the first electrode 4 and the second electrode 5 increases. Since the increase range of the electrostatic capacitance due to the pressing is different from the range where the decrease of the electrostatic capacitance due to the contact of the finger 9 occurs, both the contact position of the finger 9 and the pressing amount by the finger 9 can be detected.

  Hereinafter, this detection principle will be described in detail. The electrostatic capacity formed between the first electrode 4 and the second electrode 5 is a decrease in the electrostatic capacity due to the end of the lines of electric force applied to the finger 9 at the site where the finger 9 being pressed in contact. And the increase in capacitance that makes the distance between the first electrode 4 and the second electrode 5 closer. On the other hand, in the vicinity of the vicinity of the portion where the finger 9 being pressed is in contact, the distance between the first electrode 4 and the second electrode 5 is close due to the pressure of the finger 9, and the finger 9 is not pressed. In comparison, the capacity of the electrodes 4 and 5 is increased. Since there is no finger 9 in the vicinity of the periphery, there is no change in the fringe field, and the pushing amount (deformation amount) of the finger 9 can be obtained from the increase in capacity in the vicinity of the periphery. The push-in position can be obtained from the in-plane change of the capacitance increase / decrease.

  According to the touch sensor 1 according to the present embodiment described above, the first substrate 2 that is touch-operated is formed of a glass substrate, and therefore compared with the case where the first substrate 2 is formed of a resin film. And since the intensity | strength can be made high, it will contribute to the improvement of durability of the touch sensor 1 greatly. Further, by configuring the first electrode 4 with a thin metal wire, the strength of the first electrode 4 that is forced to be deformed can be increased as compared with the case where the first electrode 4 is configured with ITO. Property can be further improved.

  In the touch sensor 1 according to the above-described embodiment, not only the coordinate position at the contact point of the finger 9 but also the deformation amount of the first substrate 2 can be detected, and thus the first substrate 2 is deformed by a predetermined amount. Only the touch sensor 1 can be set to be effective. Such an operation method can be particularly suitably used for an operation screen for a processing machine related to factory automation (FA) in which prevention of erroneous operation is regarded as important.

  FIG. 3 shows a second embodiment of the touch sensor according to the present invention. In the first embodiment described above, the touch sensor 1 is configured such that the first substrate 2 and the second substrate 3 are separated by the seal member 6 and the space 7 is formed therebetween. The touch sensor 1 according to the embodiment is formed by filling the space 7 with the gel substance 10. For example, transparent polyacrylamide may be used as the gel substance 10, but is not limited thereto. The transparent polyacrylamide is filled in the touch sensor 1 by applying it on the second substrate 3 in a state in which a curing agent is mixed with the main agent. The gel material 10 has a refractive index of 1.35, which is close to the refractive index of glass 1.52. The gel substance 10 may be constituted by a gel film.

  According to the touch sensor 1 according to the present embodiment, the transparent gel-like substance 10 is interposed between the first substrate 2 and the second substrate 3 so that the deformation of the first substrate 2 at the time of the touch operation can be performed. Without inhibiting, and since the refractive index of the gel-like substance 10 is close to that of glass, the reflection of light at the interface between the transparent first substrate 2 and the second substrate 3 and the gel-like substance 10 is reduced. Can do. Thereby, the touch sensor 1 can be made excellent in visibility.

  Other configurations of the touch sensor 1 according to the present embodiment are the same as those of the first embodiment, and the same reference numerals are given to components common to the first embodiment. The touch sensor 1 according to the present embodiment has the same operation as that of the first embodiment.

  FIG. 4 shows a third embodiment of the touch sensor according to the present invention. In the touch sensor 1 according to the second embodiment, the gel substance 10 is filled between the first substrate 2 and the second substrate 3, but the touch sensor 1 according to the present embodiment A transparent resin layer 11 is provided as an elastic spacer between the first substrate 2 and the second substrate 3. In the present embodiment, the first electrode 4 related to the first substrate 2 is covered with the resin film 8, and the second electrode 5 related to the second substrate 3 is also covered with the resin film 12. . The resin layer 11 is in contact with the resin film 8 on the first substrate 2 and the resin film 12 on the second substrate 3, thereby separating the first substrate 2 and the second substrate 3 by their thickness. Only separated. As the resin layer 11, it is desirable to use a resin layer having a refractive index close to that of the substrates 2 and 3 from the viewpoint of the visibility of the touch panel.

  According to the touch sensor 1 according to the present embodiment, when the first substrate 2 is deformed by the pressing operation with the finger 9, the resin layer 11 as an elastic spacer is also elastically deformed according to the deformation of the first substrate 2. Thereafter, when the finger 9 is separated from the first substrate 2, the elastically deformed resin layer 11 returns to the original shape, and assists the first substrate 2 to return to the original shape. Thereby, the touch sensor 1 can improve the operation responsiveness of the 1st board | substrate 2, for example, can be used suitably also for a large sized thing where the length of one side of each board | substrate 2 and 3 exceeds 1000 mm. In addition, the touch sensor 1 can function suitably even when the first substrate 2 is made of ultra-thin glass having a thickness of 200 μm or less.

  Other configurations of the touch sensor 1 according to the present embodiment are the same as those of the first embodiment, and the same reference numerals are given to components common to the first embodiment. The touch sensor 1 according to the present embodiment has the same operation as that of the first embodiment.

  FIG. 5 shows a fourth embodiment of the touch sensor according to the present invention. In the present embodiment, the configuration of the first substrate 2 is different from that of the first embodiment. As shown in FIG. 5, the second surface 2 b (operation input surface) of the first substrate 2 is formed with a protrusion 13 (recognition protrusion) that indicates a reference position when a touch operation is performed. . In the present embodiment, one protrusion 13 formed on the second surface 2 b is illustrated, but the present invention is not limited to this, and a plurality of protrusions 13 can be formed on the first substrate 2. The protrusion 13 is made of, for example, silicon resin, but is not limited to this. Further, the protrusion 13 may have a shape whose meaning can be understood when touched with a finger 9 like a number or a specific figure.

  With the above configuration, the operator can tactilely indicate the reference position (home position) of the touch operation by touching the finger 9 with the protrusion 13 on the first substrate 2. Thereby, the operator can easily perform the operation by the blind touch based on the sense of touch of the finger 9 without looking at the operation screen of the touch panel.

  Other configurations of the touch sensor 1 according to the present embodiment are the same as those of the first embodiment, and the same reference numerals are given to components common to the first embodiment. The touch sensor 1 according to the present embodiment has the same operation as that of the first embodiment.

  In addition, this invention is not limited to the structure of the said embodiment, It is not limited to an above-described effect. The present invention can be variously modified without departing from the gist of the present invention.

  In the embodiment described above, an example in which the touch sensor 1 is operated with the finger 9 has been described. However, the present invention is not limited thereto, and the touch sensor 1 may be operated using a pen or other instrument capable of touch operation.

DESCRIPTION OF SYMBOLS 1 Touch sensor 2 1st board | substrate 3 2nd board | substrate 4 1st electrode 5 2nd electrode 7 Space 8 Resin film 10 Gel-like substance 11 Resin layer 13 Protrusion part

Claims (7)

A transparent first substrate that is touch-operated, a transparent second substrate that is spaced apart from the first substrate, a first electrode that is fixed to the first substrate, and the second A projected capacitive touch sensor comprising: a second electrode fixed to the substrate;
The first substrate is made of a flexible glass substrate,
The projected capacitive touch sensor, wherein the first electrode is made of a thin metal wire.   The projected capacitive touch sensor according to claim 1, wherein a space is provided between the first substrate and the second substrate.   The projected capacitive touch sensor according to claim 1, wherein a gel substance is interposed between the first substrate and the second substrate.   The projected capacitive touch sensor according to claim 1, further comprising an elastically deformable resin layer between the first substrate and the second substrate.   The projected capacitive touch sensor according to claim 1, further comprising a resin film that covers the first electrode.   The projected capacitive touch sensor according to claim 1, wherein a thickness of the first substrate is 20 μm or more and 500 μm or less.   The projection type electrostatic according to any one of claims 1 to 6, wherein the first substrate has an operation surface that is touch-operated, and the operation surface has a protrusion that indicates a reference position of the touch operation. Capacitive touch sensor.

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