JP6148933B2 - Touch panel - Google Patents

Description

  The present invention relates to a touch panel (a touch panel with a pressure-sensitive function) that can detect not only a pressing position on an operation surface but also a pressing force when a user touches the operation surface with a finger or a stylus.

  As such a touch panel, a device described in JP-A-5-61592 (Patent Document 1) is known. The device of Patent Document 1 includes a touch panel 2 having a configuration in which a pair of polyester film substrates 2a and 2b having electrodes 2c and 2d formed in a stripe shape are arranged to face each other via a dot-shaped spacer (Patent Document 1). 1 (see FIG. 2). The flexible touch panel 2 is arranged so as to be in close contact with the planar pressure sensor 1 (see FIG. 1 of Patent Document 1).

  In the device of Patent Document 1, when the user touches the operation surface of the touch panel 2 with a finger or the like, the electrodes 2c and 2d located at the touch portion are brought into contact with each other to be conducted. By utilizing this, the intersection position of the electrodes 2c and 2d is detected as a pressed position on the operation surface. Further, at that time, the flexible touch panel 2 is partially deformed only at the pressing position and presses the pressure-sensitive sensor 1, so that the pressing force on the operation surface depends on the output value from the pressure-sensitive sensor 1. Detected. Thereby, it is possible to simultaneously input position information and pressing force information on the operation surface.

  However, in the device of Patent Document 1, the touch panel 2 for detecting the pressing position on the operation surface and the pressure-sensitive sensor 1 for detecting the pressing force on the operation surface are configured as separate members, and further these are in the thickness direction. Are stacked in series. For this reason, there existed a subject that the thickness as the whole apparatus was large while being high in parts count and high cost.

JP-A-5-61592

  Therefore, it is desired to realize a touch panel that has a pressure-sensitive function and is cheaper and thinner than conventional ones.

The characteristic configuration of the touch panel according to the present invention is as follows:
A panel member having an operation surface and elastically deformable;
A plurality of first electrodes arranged in parallel to each other so as to be arranged in the X-axis direction on the opposite side of the operation surface of the panel member, and the electrical resistance changes according to a change in posture;
A plurality of second electrodes that face the plurality of first electrodes and are arranged in parallel to each other so as to be aligned in the Y-axis direction intersecting the X-axis direction, and the electrical resistance changes in accordance with a change in posture;
A resistance detector for detecting electrical resistances of the plurality of first electrodes and the plurality of second electrodes;
Based on the detection result by the resistance detection unit, an input determination unit that determines a pressing position in the XY coordinate system on the operation surface and a pressing force on the operation surface;
It is in the point provided with.

  According to this characteristic configuration, when the user touches the operation surface of the panel member with a finger or the like, the panel member is elastically deformed, and accordingly, the one or more first electrodes and the one or more second electrodes are also deformed. . The deformed first electrode and the second electrode change in electrical resistance according to the deformation (posture change). Therefore, by specifying the first electrode in which the resistance change is detected, the X-axis direction on the operation surface Can be determined. Similarly, the pressing position along the Y-axis direction on the operation surface can be determined by specifying the second electrode in which the resistance change is detected. Therefore, it is possible to appropriately determine the pressing position in the XY coordinate system on the operation surface. In addition, the magnitude of the pressing force on the operation surface can be appropriately determined according to the detected amount of change in electrical resistance.

  Furthermore, according to said characteristic structure, the several 1st electrode and several 2nd electrode are the hardware structure for detecting the pressing force with respect to an operation surface, and the hardware structure for detecting the pressing position on an operation surface Combined with configuration. For this reason, it is not necessary to provide a pressure-sensitive sensor separately, and a touch panel having a pressure-sensitive function can be significantly thinned as compared with the related art. In addition, a touch panel having a pressure-sensitive function can be realized with a small number of parts, and the cost can be reduced as compared with the related art. That is, it is possible to realize a touch panel that has a pressure-sensitive function and is cheaper and thinner than conventional ones.

  Hereinafter, preferred embodiments of the present invention will be described.

  As one aspect, it is preferable to further include a frame-shaped support member that supports the panel member from the side on which the first electrode and the second electrode are provided.

  According to this configuration, the panel member on which the first electrode and the second electrode are disposed is supported from the side opposite to the operation surface (the non-operation surface side) by the frame-shaped support member. Therefore, appropriate elastic deformation of the panel member when the user touches the operation surface of the panel member with a finger or the like can be ensured.

  As one aspect, it is preferable that the support member is made of a material softer than a material constituting the panel member.

  According to this configuration, when the user touches the operation surface of the panel member with a finger or the like, the panel member is entirely directed toward the non-operation surface side while the inner peripheral side portion of the frame-shaped support member is deformed. Elastically deforms so that it becomes convex. Therefore, it can suppress that only a part of panel member deform | transforms locally, and a 1st electrode and a 2nd electrode produce a shrink deformation. In other words, the deformation (posture change) of the first electrode and the second electrode can be substantially extended only. Therefore, the detection accuracy of the pressing force on the operation surface can be increased.

  As one aspect, it is preferable that the width of each side of the support member in a plan view is 0.4 mm to 2 mm.

  If the width of the support member is less than 0.4 mm, the support strength may be reduced, and the certainty of proper support of the panel member may not be ensured. On the other hand, when the width of the support member exceeds 2 mm, only a part of the panel member is locally deformed, and the first electrode and the second electrode may be contracted and deformed. Therefore, by setting the width of the support member to 0.4 mm to 2 mm as described above, the effect of improving the detection accuracy of the pressing force described above can be appropriately ensured.

As one aspect, it is preferable that each of at least one of the first electrode and the second electrode is formed so as to become narrower from the central portion to the both end portions in the extending direction. .
In other words, each of the plurality of first electrodes is formed so as to become narrower from the central portion in the direction orthogonal to the X-axis direction toward both ends, and / or of the plurality of second electrodes. Each of them is preferably formed so as to become narrower as it goes from the central portion to both ends in the direction orthogonal to the Y-axis direction.

  Even if the pressing force on the operation surface is the same, the degree of elastic deformation is smaller when the peripheral edge of the panel member is pressed than when the center is pressed. For this reason, the degree of deformation (posture change) of the first electrode and the second electrode is also smaller at both end portions than in the central portion in each extending direction. Therefore, as described above, each of the plurality of first electrodes is formed so as to become narrower as it goes from the central portion toward both ends, thereby extending the entire extending direction (direction orthogonal to the X-axis direction). Thus, variation in the detection sensitivity of the pressing force can be suppressed. Similarly, by forming each of the plurality of second electrodes so as to become narrower from the center toward both ends, the entire extension direction (direction perpendicular to the Y-axis direction) is pushed. Variations in pressure detection sensitivity can be suppressed. Therefore, the detection accuracy of the pressing force can be further increased.

As one aspect, at least one of the first electrode and the second electrode is formed such that electrodes arranged adjacent to each other are alternately arranged at one end and the other end in the extending direction. It is preferable that they are connected and formed in a zigzag shape as a whole in plan view.
In other words, a plurality of the first electrodes are arranged such that the first electrodes arranged adjacent to each other are alternately connected at one end and the other end in the direction orthogonal to the X-axis direction, And / or a plurality of the second electrodes arranged adjacent to each other, the one end and the other in the direction perpendicular to the Y-axis direction. It is preferable that the side ends are alternately connected and formed in a zigzag shape in plan view as a whole.

  According to this configuration, the plurality of first electrodes and / or the plurality of second electrodes are connected to each other and connected to one as a whole. Presence / absence can be easily determined. For example, until it is determined that a pressing operation has been performed, scanning of each electrode can be paused, and power consumption can be reduced.

  As one aspect, the input determination unit includes the first electrode that gives a resistance change that is a maximum among the plurality of first electrodes during a pressing operation on the operation surface with reference to an electrical resistance in a non-pressing state. It is preferable to specify the pressing position as a combination of a position in the X-axis direction and a position in the Y-axis direction of the second electrode that gives a maximum resistance change among the plurality of second electrodes.

  According to this configuration, the pressing position in the XY coordinate system can be appropriately determined by a relatively simple calculation process. That is, the pressing position can be determined easily and appropriately.

  As one aspect, the input determination unit includes an estimated resistance value at each position in the X-axis direction based on a relationship between positions of the plurality of first electrodes in the X-axis direction and resistance values actually detected during a pressing operation. And determining an estimated resistance value at each position in the Y-axis direction from the relationship between the position of the plurality of second electrodes in the Y-axis direction and the resistance value actually detected during the pressing operation. It is preferable to specify the pressing position as a combination of the position in the X-axis direction and the position in the Y-axis direction that gives the peak value.

  According to this configuration, the pressing position in the XY coordinate system can be determined in more detail. That is, the pressing position can be determined with high accuracy.

  As one aspect, the information processing apparatus further includes a storage unit that stores in advance relationship information that defines a correlation between the pressing force on the operation surface and the electrical resistance change amount from the non-pressed state, and the input determination unit includes the relationship information It is preferable to determine the pressing force according to the actual electric resistance change amount based on the actual electric resistance change amount.

  According to this configuration, it is possible to easily and appropriately determine the pressing force on the operation surface based on the relationship information prepared in advance.

Perspective view of an electronic device equipped with a pressure-sensitive touch panel II-II sectional view in FIG. Exploded perspective view of touch panel Schematic diagram showing the connection relationship between each electrode and control unit Block diagram showing the configuration of the controller Schematic diagram showing the deformation of the touch panel accompanying the pressing operation The schematic diagram which shows an example of the resistance value detected by each electrode with pressing operation The schematic diagram which shows an example of the resistance value detected by each electrode with pressing operation Relationship map showing the relationship between resistance value change and pressing force Schematic showing another form of electrode shape Schematic showing another aspect of the connection form of multiple electrodes Flow chart showing the flow of detection processing of pressing position and pressing force

  An embodiment of a touch panel according to the present invention will be described with reference to the drawings. The touch panel 5 according to the present embodiment is provided in the electronic device 1 such as a mobile phone or a portable game machine, and functions as a touch input device. In the present embodiment, a touch panel 5 mounted on a multi-function mobile phone (smart phone) as a kind of the electronic device 1 will be described as an example. In the following description, a side on which an input surface (an operation surface 10a described later) of the touch panel 5 as a touch input device is located is referred to as a “front side”. This “front side” is also the side facing the user who operates the electronic device 1. On the contrary, the back side when viewed from the user operating the electronic device 1 is referred to as a “back side”.

  As shown in FIGS. 1 and 2, the electronic device 1 is arranged in a substantially rectangular parallelepiped casing 3, a display device 4 built in the casing 3, and the display device 4 so as to overlap the front side. Touch panel 5. The housing 3 is made of synthetic resin. The housing | casing 3 is provided with the recessed part 3a opened in a rectangular shape toward the front side. The concave portion 3a is formed to have a step, and this step portion functions as a support portion 3b that supports the touch panel 5 from the back side. The support portion 3b is formed in a rectangular frame shape (frame shape) corresponding to the shape of the recess 3a. The display device 4 is stored in a region (first storage recess) on the back side of the support portion 3b (stepped portion), and is supported by the support portion 3b in a region on the front side (second storage recess). The touch panel 5 is accommodated. The display device 4 is constituted by, for example, a liquid crystal display panel or an organic EL display panel.

  The shape and size of the recess 3a (first storage recess and second storage recess) can be appropriately set according to the shape and size of the display device 4 and the touch panel 5. In the present embodiment, as an example, both the display device 4 and the touch panel 5 have a substantially rectangular parallelepiped shape, and the dimensions in a plan view (viewed from the front side) of the touch panel 5 are larger than those of the display device 4. Is bigger. The recess 3a is in contact with the side surface of the first storage recess and the side surface of the display device 4, and is in contact with the side surface of the second storage recess and the side surface of the touch panel 5, and the surface of the display device 4 and the surface of the support portion 3b. And the surface of the housing 3 and the surface of the touch panel 5 are formed to have substantially the same height.

  In the present embodiment, when the user touches the operation surface 10a with a finger or a stylus, the touch panel 5 simultaneously detects the magnitude of the pressing force on the operation surface 10a in addition to the pressing position on the operation surface 10a. It is configured as follows. That is, the touch panel 5 according to the present embodiment is configured as a pressure-sensitive touch panel.

  As shown in FIG. 3, the touch panel 5 includes a panel member 10, a first electrode forming member 20, a second electrode forming member 30, and a support member 50. These are laminated | stacked in order of description toward the back side from the front side. The support member 50 is disposed on the support portion 3b of the housing 3, the second electrode forming member 30 is disposed on the support member 50, the first electrode forming member 20 is disposed on the second electrode forming member 30, The panel member 10 is disposed on the first electrode forming member 20 (see also FIG. 2). These are bonded to each other by, for example, a pressure sensitive adhesive (PSA).

  Moreover, in this embodiment, the panel member 10, the 1st electrode formation member 20, and the 2nd electrode formation member 30 are formed in the rectangular shape by planar view, and are piled up. Then, the direction along one side of the four sides forming the rectangular shape is defined as an “X-axis direction” in the present embodiment, and another side that intersects (is orthogonal to in this example) the one side. The direction along is defined as “Y-axis direction” in the present embodiment. In the present embodiment, an XY coordinate system (XY orthogonal coordinate system) is configured based on the X-axis direction and the Y-axis direction that are orthogonal to each other. Note that the XY coordinate system may be configured based on the X-axis direction and the Y-axis direction that intersect each other at non-right angles.

  The panel member 10 is a plate-like member disposed on the forefront side of the touch panel 5. The panel member 10 has an operation surface 10a on the front surface thereof. The operation surface 10 a is a surface that is touched (to be operated) by a user's finger or the like when the user inputs a predetermined operation to the electronic device 1. In the present embodiment, the panel member 10 functions as a protective panel that protects the first electrode forming member 20 and the second electrode forming member 30. The panel member 10 preferably has transparency, scratch resistance, antifouling properties and the like. Such a panel member 10 can be comprised by the glass plate using soda glass, tempered glass, etc., for example, and is made into the glass thin plate in this embodiment. In addition to this, the panel member 10 may be configured using a resin material such as polymethyl methacrylate or polycarbonate, an organic-inorganic hybrid material, or the like. By using a material excellent in strength, the panel member 10 can be thinned. The thickness of the panel member 10 can be 0.4 mm-1.5 mm, for example. Further, the panel member 10 is originally elastically deformable, but there is also an advantage that it is easily elastically deformed by making it thin.

  The first electrode forming member 20 includes a first substrate 21 and a plurality (eight in this example) of first electrodes 22 formed on the first substrate 21. The first substrate 21 is preferably configured using a material excellent in transparency, flexibility, insulation, and the like. Examples of materials that satisfy such requirements include general-purpose resins such as polyethylene terephthalate and acrylic resins, general-purpose engineering resins such as polyacetal resins and polycarbonate resins, and super engineering resins such as polysulfone resins and polyphenylene sulfide resins. Is exemplified. The thickness of the 1st board | substrate 21 can be 25 micrometers-100 micrometers, for example. In this embodiment, the 1st board | substrate 21 is comprised with the polyethylene terephthalate film.

  In the present embodiment, the first electrode 22 is formed on the surface of the first substrate 21 on the front side (panel member 10 side). The plurality of first electrodes 22 are arranged in parallel to each other so as to be arranged at a predetermined interval in the X-axis direction. In the present embodiment, the first electrode 22 is formed in a stripe shape (a linear shape having a certain width). The first electrode 22 may be formed in, for example, a wave shape or a zigzag shape. In any case, each of the first electrodes 22 is formed so as to extend along the Y-axis direction as a whole. The 1st electrode 22 is comprised using the material from which an electrical resistance changes according to a posture change. Moreover, it is preferable that the 1st electrode 22 is comprised using the material excellent in transparency. Examples of materials that satisfy these requirements include metal oxides such as tin oxide, indium oxide, antimony oxide, zinc oxide, cadmium oxide, and ITO (Indium Tin Oxide), silver nanowires, carbon nanotubes, and conductive polymers. Etc. are exemplified. The 1st electrode 22 is a transparent conductive film comprised using these materials, The thickness can be 5 nm-10000 nm, for example. In the present embodiment, the first electrode 22 is composed of an ITO thin film.

  Examples of the method for forming the first electrode 22 include a method in which a transparent conductive film is formed on the entire surface of the first substrate 21 and then unnecessary portions are removed by etching. The entire surface of the transparent conductive film can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, a CVD method, a roll coater method, or the like. Etching can be performed by immersing the resist in an etching solution such as hydrochloric acid after forming a resist by a photolithography method, a screen printing method, or the like in a portion to be left as an electrode. Etching is carried out by removing the transparent conductive film where the resist is not formed by spraying an etching solution after the resist is formed, and then swelling or dissolving the resist by immersion in a solvent. It can also be done. Etching can also be performed with a laser.

  The second electrode forming member 30 includes a second substrate 31 and a plurality (eight in this example) of second electrodes 32 formed on the second substrate 31. The second substrate 31 is also preferably configured using a material excellent in transparency, flexibility, insulation, and the like. The material constituting the second substrate 31 and the thickness of the second substrate 31 can be considered in the same manner as the first substrate 21.

  In the present embodiment, the second electrode 32 is formed on the surface of the second substrate 31 on the front side (panel member 10 and first electrode forming member 20 side). The plurality of second electrodes 32 are arranged to face the plurality of first electrodes 22 with a predetermined interval in the thickness direction. The plurality of second electrodes 32 are arranged in parallel to each other so as to be arranged at a predetermined interval in the Y-axis direction. In the present embodiment, the second electrode 32 is formed in a stripe shape (a linear shape having a certain width). The second electrode 32 may be formed in, for example, a wave shape or a zigzag shape. In any case, each of the second electrodes 32 is formed so as to extend along the X-axis direction as a whole. Thereby, the 1st electrode 22 and the 2nd electrode 32 are arrange | positioned so that it may mutually cross | intersect (this example orthogonally cross) by planar view. Similar to the first electrode 22, the second electrode 32 is configured using a material whose electrical resistance changes in accordance with a change in posture. Moreover, it is preferable that the 2nd electrode 32 is comprised using the material excellent in transparency. The material constituting the second electrode 32 and the thickness of the second electrode 32 can be considered in the same manner as the first electrode 22. The method for forming the second electrode 32 can also be considered in the same manner as the first electrode 22.

  In the present embodiment, each of the plurality of first electrodes 22 is disposed in an island shape on the first substrate 21 without being connected to each other. Similarly, the plurality of second electrodes 32 are also arranged in an island shape on the second substrate 31 so as not to be connected to each other. The plurality of first electrodes 22 and the plurality of second electrodes 32 are arranged so as to form a lattice shape in plan view as a whole (see FIG. 4). In addition, the 1st board | substrate 21 exists between the 1st electrode 22 and the 2nd electrode 32, and the 1st electrode 22 and the 2nd electrode 32 are arrange | positioned through the 1st board | substrate 21 in the thickness direction. Yes. In the present embodiment, since there is no air gap between the first electrode 22 and the second electrode 32, the optical characteristics can be improved. That is, it is possible to suppress the reflection of light and suppress a decrease in transmittance.

  The support member 50 supports the panel member 10 from the back side (side on which the first electrode 22 and the second electrode 32 are provided). The support member 50 supports the panel member 10 from the back side through the first electrode forming member 20 in which the first electrode 22 is formed and the second electrode forming member 30 in which the second electrode 32 is formed. The support member 50 is formed in a frame shape. The support member 50 is formed in a rectangular frame shape in plan view so as to correspond to the shape of the support portion 3 b of the housing 3. The support member 50 is provided so as to support the peripheral part (near each side) of the panel member 10 and each electrode forming member 20, 30 formed in a rectangular shape. The support member 50 is preferably made of a material that has elasticity or flexibility and a formability that can appropriately support the panel member 10 and the like. Here, in particular, the support member 50 is preferably made of a material softer than the material constituting the panel member 10. “Softness” is a scale representing the magnitude of deformation with respect to stress, and in this application, the evaluation is based on Young's modulus. That is, the support member 50 is preferably made of a material having a Young's modulus smaller than that of the material constituting the panel member 10. For example, a material having a Young's modulus of 1 M · Pa or less, preferably 0.5 M · Pa to 1 M · Pa is preferable.

  Examples of the material that satisfies such requirements include urethane foam, acrylic foam, silicone rubber, sponge, gel, and the like. A double-sided tape having adhesive layers on both sides may be used. The width dimension in plan view of each side constituting the rectangular frame-shaped support member 50 is preferably set as narrow as possible within a range in which the panel member 10 and the like can be appropriately supported. The width of the support member 50 can be set to 0.4 mm to 2 mm, for example. Moreover, it is preferable that the thickness of the support member 50 is set to be relatively thick so that the displacement width due to elastic deformation of the panel member 10 and the electrode forming members 20 and 30 can be absorbed. The thickness of the support member 50 is preferably 0.1 mm to 0.4 mm, for example.

  The panel member 10 on which the first electrode 22 and the second electrode 32 are arranged is supported by the support portion 3 b of the housing 3 through the soft and relatively thick frame-shaped support member 50. At this time, when the user touches the operation surface 10a of the panel member 10 with a finger or the like, the entire portion of the panel member 10 faces the non-operation surface side while the inner peripheral side portion of the frame-shaped support member 50 is deformed. And is elastically deformed so as to be convex (see FIG. 6). That is, the support form of the panel member 10 by the support member 50 is a simple support type. Accordingly, only a part of the panel member 10 (specifically, the vicinity of the supported portion supported by the support member 50) is locally deformed, and the first electrode 22 and the second electrode 32 are contracted and deformed. Can be suppressed. In other words, the deformation (posture change) of the first electrode 22 and the second electrode 32 can be substantially extended only.

  As shown in FIG. 4, each of the plurality of first electrodes 22 is connected to the control unit 60 via a lead wiring 23. A switch 24 is provided in each routing wiring 23 extending from the plurality of first electrodes 22. In the present embodiment, the switch 24 is configured using a switching element. Each of the plurality of second electrodes 32 is connected to the control unit 60 via a lead wiring 33. A switch 34 is provided in each routing wiring 33 extending from the plurality of second electrodes 32. In the present embodiment, the switch 34 is configured using a switching element. Examples of the switching element include an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and a GTO (Gate Turn-Off thyristor).

  The lead wirings 23 and 33 are configured using a metal such as gold, silver, copper, and nickel, or a conductive paste such as carbon. Although not shown in FIG. 4 for simplification, the other end sides of the electrodes 22 and 32 are also connected to the control unit 60 via routing wires. Each switching element constituting the switches 24 and 34 is connected to the control unit 60 via a control signal line.

  The control unit 60 includes an arithmetic processing unit such as a CPU as a core member, and is configured by hardware and / or software (program) or both as a functional unit for performing various processes on input data. . As shown in FIG. 5, the control unit 60 includes a switching control unit 61, a resistance detection unit 63, and an input determination unit 65. The input determination unit 65 includes a position determination unit 66 and a pressing force determination unit 67. Moreover, the control part 60 is connected with the memory | storage part 70 so that information communication is possible. The storage unit 70 is configured by a memory such as a RAM (Random Access Memory) or an EEPROM (Electrically Erasable Programmable Read Only Memory). The storage unit 70 stores relation data 71 and reference data 72.

  The switching control unit 61 controls on / off of the switching elements that constitute the switches 24 and 34. For example, when the switches 24 and 34 are formed of IGBTs, the switching control unit 61 controls the on / off of each IGBT by individually generating a gate drive signal for each IGBT. The same applies to the case of using other switching elements. The switching control unit 61 selectively connects the first electrode 22a to the resistance detection unit 63, for example, by turning on the IGBT configuring the switch 24a corresponding to the first electrode 22a. Further, the switching control unit 61 selectively connects the first electrode 22b to the resistance detection unit 63 by turning on the IGBT configuring the switch 24b corresponding to the first electrode 22b, for example. The same applies to the other first electrodes 22c to 22h (switches 24c to 24h). The same applies to the second electrodes 32c to 32h (switches 34c to 34h).

  In the present embodiment, the switching control unit 61 controls each of the switches 24a to 24h so that any one of the switches 24a to 24h is sequentially turned on. And it repeats and executes it sequentially. Thereby, each 1st electrode 22a-22h is selectively connected to the resistance detection part 63 sequentially. In addition, the switching control unit 61 controls the switches 34a to 34h so that any one of the switches 34a to 34h is sequentially turned on. And it repeats and executes it sequentially. Thereby, each 2nd electrode 32a-32h is selectively connected to the resistance detection part 63 sequentially.

  The resistance detector 63 detects the electrical resistance of the plurality of first electrodes 22 and the plurality of second electrodes 32. For this reason, the resistance detection part 63 is comprised including the resistance detection circuit. This resistance detection circuit is configured by a known bridge circuit (Wheatstone bridge circuit). The resistance detector 63 detects the electrical resistance (resistance value) based on the voltage across the electrodes 22 and 32 selectively connected by the switching controller 61. The resistance detector 63 sequentially detects the resistance values of the first electrodes 22a to 22h. Further, the resistance detector 63 sequentially detects the resistance values of the second electrodes 32a to 32h. The scanning of each first electrode 22 and the scanning of each second electrode 32 may be performed in synchronization or alternately. Information on the value detected by the resistance detection unit 63 is transmitted to the input determination unit 65.

  The position determination unit 66 included in the input determination unit 65 determines the pressed position in the XY coordinate system on the operation surface 10a based on the detection result by the resistance detection unit 63. Here, FIG. 6 schematically shows a state where the user's finger gradually approaches the operation surface 10a and then pushes the operation surface 10a with a gradually large force. FIG. 7 shows the relationship between the pressed position (position represented by “X”) and the resistance value changes of the electrodes 22a to 22h and 32a to 32h detected by the resistance detector 63 in the middle state of FIG. This is shown schematically. As can be easily understood from this figure, the first electrode 22 that is closer to the pressing position in the X-axis direction and has a large degree of deformation (posture change) has a large resistance value change, and the first electrode 22 that is farther from the pressing position. The resistance value change is small. And the resistance value change of the 1st electrode 22 which left | separated predetermined distance or more along the X-axis direction from the press position has converged on substantially zero. The change in resistance value of the first electrode 22 refers to the resistance value (first reference resistance value) of each first electrode 22 when the operation surface 10a is not pressed at all (non-pressed state) and the operation surface 10a. It is a difference with the resistance value of each 1st electrode 22 measured in the state (pressed state) in which one part is pressed. That is, the resistance value change represents a change in the absolute value of the resistance value of the first electrode 22 when a pressing force is applied, and the value may be positive or negative. In the present embodiment, the position determination unit 66 uses the first reference resistance value as a reference, and is the maximum among the plurality of first electrodes 22 during the pressing operation on the operation surface 10a (maximum when a plurality of positions are pressed). By specifying the first electrode 22 that gives a change in resistance, the X coordinate of the pressed position is determined.

  Similarly, in the Y-axis direction, the second electrode 32 that is closer to the pressing position in the Y-axis direction and has a large degree of deformation (posture change) has a large change in resistance value, and the second electrode 32 that is farther from the pressing position. The resistance value change is small. And the resistance value change of the 2nd electrode 32 which left | separated predetermined distance or more along the Y-axis direction from the press position has converged on substantially zero. The change in the resistance value of the second electrode 32 refers to the resistance value (second reference resistance value) of each second electrode 32 in the non-pressed state and the resistance value of each second electrode 32 actually measured in the pressed state. It is a difference. That is, the resistance value change represents a change in the absolute value of the resistance value of the second electrode 32 when a pressing force is applied, and the value may be positive or negative. In the present embodiment, the position determination unit 66 uses the second reference resistance value as a reference, and the second electrode that gives the maximum (or maximum) resistance change among the plurality of second electrodes 32 during the pressing operation on the operation surface 10a. By specifying 32, the Y coordinate of the pressed position is determined.

  As described above, the position determination unit 66 gives a maximum (or maximum) resistance change among the plurality of first electrodes 22 during the pressing operation on the operation surface 10a with reference to the resistance value detected in the non-pressing state. As a combination of the position in the X-axis direction of the first electrode 22 and the position in the Y-axis direction of the second electrode 32 that gives the maximum (or maximum) resistance change among the plurality of second electrodes 32, the pressing position is Identify. With this configuration, it is possible to determine the pressed position in the XY coordinate system by a relatively simple calculation process.

  However, in the above aspect, the resolution for detecting the pressed position is limited to the pitch width of the electrodes 22 and 32. Therefore, the position determination unit 66 may be configured to perform an interpolation calculation using the resistance value actually detected by the resistance detection unit 63 and specify the pressed position based on the calculation result. For example, the position determination unit 66 continuously calculates the estimated resistance value at each position in the X-axis direction from the relationship between the position of the first electrodes 22a to 22h obtained discretely in the X-axis direction and the actual resistance value. Ask. And the position determination part 66 determines the X coordinate of a press position by pinpointing the position of the X-axis direction which gives the peak value of an estimated resistance value. The Y coordinate of the pressed position is determined in the same manner.

  That is, the position determination unit 66 obtains an estimated resistance value at each position in the X-axis direction from the relationship between the positions in the X-axis direction of the plurality of first electrodes 22 and the resistance value at the time of the pressing operation on the operation surface 10a. An estimated resistance value at each position in the Y-axis direction is obtained from the relationship between the position of the second electrode 32 in the Y-axis direction and the resistance value during the pressing operation, and the position in the X-axis direction that gives the peak value of each estimated resistance value; The pressing position may be specified as a combination with the position in the Y-axis direction. In this way, the pressed position in the XY coordinate system on the operation surface 10a can be determined in more detail.

  The pressing force determination unit 67 included in the input determination unit 65 determines the pressing force on the operation surface 10 a based on the detection result by the resistance detection unit 63. Here, FIG. 8 schematically shows the relationship between the pressed position and the resistance values of the electrodes 22a to 22h and 32a to 32h detected by the resistance detector 63 in the lower state of FIG. As can be easily understood from a comparison between this figure and FIG. 7 described above, as the force for pushing the operation surface 10a increases and the degree of deformation (posture change) of the touch panel 5 increases, the electrodes 22, 32 are increased. The amount of change in resistance value at becomes large. Therefore, by determining in advance the relationship between the pressing force on the operation surface 10a and the change amount of the resistance value, the pressing force on the operation surface 10a can be quantitatively evaluated from the actual change amount of the resistance value.

  In the present embodiment, relationship data 71 defining the correlation between the pressing force on the operation surface 10a and the amount of change in resistance value from the non-pressed state is stored in the storage unit 70 in advance. The relation data 71 may be in the form of a relation map as shown in FIG. 9, for example, or may be in the form of a predetermined relational expression. Further, the storage unit 70 has reference data 72 obtained by measuring in advance the resistance values (first reference resistance value and second reference resistance value) of each first electrode 22 and each second electrode 32 in the non-pressed state. Is stored and provided. The pressing force determination unit 67 determines the pressing force according to the change amount of the actual resistance value based on the relationship data 71 and the actually detected resistance value change (difference between the actual resistance value and each reference resistance value). To do. The “change amount of the actual resistance value” is the change amount at each position when a plurality of positions are pressed. Thereby, the pressing force in each pressing position can be determined individually. In other words, multi-force support is possible.

  Further, the “change amount of the actual resistance value” can be a value according to the determination method of the pressed position in the XY coordinate system by the position determination unit 66. That is, the determination method of the pressing force by the pressing force determination unit 67 can be varied depending on whether or not the position determination unit 66 specifies the pressing position based on the calculation result of the interpolation calculation. For example, when the position determination unit 66 does not perform the interpolation calculation, the pressing force determination unit 67 can be configured not to perform the interpolation calculation. In this case, the pressing force determination unit 67 uses the electrical resistance detected in the non-pressed state as a reference, and the maximum (or the plurality of first electrodes 22 or the plurality of second electrodes 32 during the pressing operation on the operation surface 10a respectively (or The pressing force is determined in accordance with the resistance change amount of the electrodes 22 and 32 that gives the resistance change to the maximum). With this configuration, the pressing force on the operation surface 10a can be determined by a relatively simple calculation process.

  On the other hand, when the position determination unit 66 performs the interpolation calculation, the pressing force determination unit 67 can also be configured to perform the interpolation calculation. In this case, the pressing force determination unit 67 obtains an estimated resistance value at each position in the X-axis direction from the relationship between the position in the X-axis direction of the plurality of first electrodes 22 and the resistance value actually detected during the pressing operation. And / or the estimated resistance value in each position in the Y-axis direction is obtained from the relationship between the position in the Y-axis direction of the plurality of second electrodes 32 and the resistance value actually detected during the pressing operation, and the respective estimated resistance values Determine the pressing force according to the peak value. In this way, the pressing force on the operation surface 10a can be determined in more detail.

  In addition, the pressing force determination part 67 is based on the resistance value of the 2nd electrode 32 which is an electrode arrange | positioned at least on the opposite side to the panel member 10 among the 1st electrode 22 and the 2nd electrode 32. It is preferable to determine the pressing force for 10a. Compared to the first electrode 22, the second electrode 32 is a neutral axis of the touch panel main body composed of the panel member 10, the first electrode forming member 20, and the second electrode forming member 30 (in a thick dotted line in the lower part of FIG. 6). It is arranged at a position farther away from the display. For this reason, the degree of deformation (posture change) when the pressing force is applied to the operation surface 10 a and the touch panel body is integrally elastically deformed is larger in the second electrode 32 than in the first electrode 22. Become. Therefore, the detection sensitivity can be increased by configuring the pressing force to be determined based on the resistance value of the second electrode 32. As a result, the detection accuracy of the pressing force can be increased. Of course, the pressing force may be determined based on the resistance values of both the first electrode 22 and the second electrode 32.

  Further, as described above, in the present embodiment, the panel member 10 on which the first electrode 22 and the second electrode 32 are arranged is supported via a soft and thick frame-shaped support member 50. Therefore, the support form of the panel member 10 by the support member 50 is a simple support type, and the deformation (posture change) of the first electrode 22 and the second electrode 32 can be substantially extended only. Thereby, the detection accuracy of the pressing force can be further increased.

  As described above, the input determination unit 65 determines both the pressing position in the XY coordinate system on the operation surface 10a and the pressing force on the operation surface 10a based on the detection result by the resistance detection unit 63. Thereby, in addition to the normal position detection function, the touch panel 5 having a pressure sensitive function is realized. If the target pressing operation is the same, there is a correlation between the pressing force determined based on the resistance value of the first electrode 22 and the pressing force determined based on the resistance value of the second electrode 32. There is (theoretically the same). For this reason, if it is set as the structure which determines a pressing force based on the resistance value of both the electrodes 22 and 32, even if the several position on the operation surface 10a is pressed, based on the correspondence of a pressing force. Each pressing position can be determined appropriately. That is, the so-called ghost detection problem is avoided and multi-touch support is possible.

  At this time, in this embodiment, the thin touch panel 5 is realized by adopting the OGS (One Glass Solution) technology for forming the two electrodes 22 and 32 on the panel member 10 made of a glass thin plate. Further, in the present embodiment, the plurality of first electrodes 22 and the plurality of second electrodes 32 share both a hardware configuration for realizing the position detection function and a hardware configuration for realizing the pressure sensitive function. For this reason, it is not necessary to provide a pressure-sensitive sensor separately, and the touch panel 5 having a pressure-sensitive function can be significantly thinned compared to the conventional case. In addition, the touch panel 5 having a pressure-sensitive function can be realized with a small number of parts, and the cost can be reduced as compared with the related art. That is, it is possible to realize a touch panel 5 that has a pressure-sensitive function and is cheaper and thinner than conventional ones.

  Information on the pressing position and the pressing force determined by the input determining unit 65 is provided to the electronic device 1 as position information and pressing force information. In the electronic device 1, various processes according to the application are executed based on the position information and the pressing force information.

[Other Embodiments]
Finally, other embodiments of the touch panel according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) In the above embodiment, the configuration in which the first electrode 22 and the second electrode 32 are formed in a stripe shape having a constant width has been described as an example. However, the embodiment of the present invention is not limited to this. Each of at least one of the first electrode 22 and the second electrode 32 may be configured such that its thickness changes according to the position in the extending direction. That is, each of at least one of the first electrode 22 and the second electrode 32 may be formed so as to become narrower from the central portion toward the both ends in the extending direction. Specifically, for example, with respect to the second electrode 32, as shown in FIG. 10, each of the plurality of second electrodes 32 is directed from the center to both ends in the X-axis direction (direction perpendicular to the Y-axis direction). Accordingly, it is preferable that the width is narrow. Similarly, for example, with respect to the first electrode 22, each of the plurality of first electrodes 22 is formed so as to become narrower from the center to both ends in the Y-axis direction (direction orthogonal to the X-axis direction). It is preferable (not shown). Each of the electrodes 22 and 32 may be formed so as to gradually become narrower (continuously) as shown in FIG. 10, or may be formed so as to become narrower in stages (see FIG. 10). Not shown).

  Even when the pressing force on the operation surface 10a is the same, the degree of elastic deformation is smaller when the peripheral portion of the panel member 10 is pushed than when the central portion is pushed. For this reason, the degree of deformation (posture change) of the first electrode 22 and the second electrode 32 is also smaller at both end portions than in the central portion in each extending direction. Therefore, if configured as described above, it is possible to suppress variations in the detection sensitivity of the pressing force over the entire extending direction, and it is possible to further increase the detection accuracy of the pressing force. The second electrode 32 disposed at a position further away from the neutral axis of the touch panel body may be used as an electrode that forms the core of the pressure-sensitive function. Therefore, it is preferable to form at least the second electrode 32 so as to become narrower from the center to both ends in the extending direction (X-axis direction in this example).

(2) In the above embodiment, a configuration in which the first electrode 22 and the second electrode 32 are arranged in an island shape on the substrates 21 and 31 without being connected to each other is taken as an example. explained. However, the embodiment of the present invention is not limited to this. In each of at least one of the first electrode 22 and the second electrode 32, electrodes arranged adjacent to each other are alternately connected at one end and the other end in the extending direction, As a whole, it may be formed in a zigzag shape in plan view. Specifically, as shown in FIG. 11, the first electrodes 22 in which the plurality of first electrodes 22 are arranged adjacent to each other are connected to each other via the connection wiring 25 on one side end and the other side in the Y-axis direction. They may be alternately connected to the end portions, and may be formed in a zigzag shape in plan view as a whole. Further, the second electrodes 32 arranged adjacent to each other are alternately connected to each other at one end and the other end in the X-axis direction via the connection wiring 35, As a plan view, it may be formed in a zigzag shape. The connection wirings 25 and 35 are configured using a metal such as gold, silver, copper, and nickel, or a conductive paste such as carbon.

  In such a configuration, the plurality of first electrodes 22 are connected to each other and connected as a whole. In this case, both ends of the first electrode 22 as a whole and the connection wirings 25 respectively connecting the pair of first electrodes 22 are routed through the routing wirings in which the switches 24a to 24i are interposed. To the control unit 60. Only some of them may be connected to the control unit 60. The same applies to the plurality of second electrodes 32. And the function similar to said embodiment is realizable by controlling the state of these switches 24a-24i and 34a-34i appropriately. In such a configuration, the switches 24a and 24i (34a and 34i) are turned on and the other switches 24b to 24h (34b to 34h) are turned off and waited until the actual pressing operation is performed. Thus, power consumption can be reduced.

  The flow of detection processing of the pressing position and pressing force in this case is shown in the flowchart of FIG. First, the switches 24a and 24i (34a and 34i) are turned on, and the resistance value between both ends of the first electrode 22 (second electrode 32) as a whole is detected (step # 01). It waits until resistance value change is detected (step # 02: No), and when resistance value change is detected (step # 02: Yes), between the both ends of each 1st electrode 22 (each 2nd electrode 32). Resistance values are sequentially detected (step # 03). Based on the resistance values of the electrodes 22 and 32, both the pressing position on the operation surface 10a and the pressing force on the operation surface 10a are determined (step # 04). The position information and the pressing force information thus derived are output to the electronic device 1 (step # 05).

(3) In the above embodiment, the configuration in which the first electrode 22 and the second electrode 32 are formed on the front-side surfaces of the first substrate 21 and the second substrate 31 has been described as an example. However, the embodiment of the present invention is not limited to this. For example, the first electrode 22 and the second electrode 32 may be formed on the back side surfaces of the first substrate 21 and the second substrate 31, respectively. Further, for example, the first electrode 22 and the second electrode 32 may be formed on surfaces of the first substrate 21 and the second substrate 31 that face each other. However, even in this case, an insulating layer is provided between the electrodes 22 and 23 so that the first electrode 22 and the second electrode 32 are not short-circuited. This insulating layer may be, for example, an air layer (air gap) including dot-shaped spacers, or may also serve as an adhesive layer.

(4) In the above embodiment, the configuration in which the panel member 10, the first electrode forming member 20, and the second electrode forming member 30 are bonded together has been described as an example. That is, the configuration in which the panel member 10, the first substrate 21 on which the first electrode 22 is formed, and the second substrate 31 on which the second electrode 32 is formed has been described as an example. However, the embodiment of the present invention is not limited to this. For example, at least the first substrate 21 is omitted, and the panel member 10, the first electrode 22, and the second electrode 32 are simply bonded together (the second substrate 31 may exist on the back side). Also good. However, even in this case, an insulating layer is provided between the electrodes 22 and 23 so that the first electrode 22 and the second electrode 32 are not short-circuited. This insulating layer may also serve as an adhesive layer.

(5) In the above embodiment, a configuration in which the panel member 10 is a protective panel that protects the first electrode forming member 20 (first electrode 22) and the second electrode forming member 30 (second electrode 32) will be described as an example. did. However, the embodiment of the present invention is not limited to this. For example, a known touch panel may be used as the panel member 10. In this case, the panel member 10 functions as an internal touch panel incorporated in the touch panel 5. As the internal touch panel, a resistance film type or a capacitance type can be used. If it is set as the structure provided with such an internal touch panel, a position detection function will be exhibited also by the said internal touch panel, and the press position in the XY coordinate system in the operation surface 10a can be determined more accurately.

(6) In the above embodiment, the position determining unit 66 and the pressing force determining unit 67 have been described with the configuration in which the pressing position and the pressing force are respectively determined using the detection result by the resistance detecting unit 63 as they are. . However, the embodiment of the present invention is not limited to this. For example, the position determination unit 66 and the pressing force determination unit 67 may determine the pressing position and the pressing force by using only the values detected by the resistance detection unit 63 that exceed a predetermined threshold. In this way, it is possible to suppress the occurrence of erroneous input based on the user's unintended contact with the operation surface 10a.

(7) In the above embodiment, an example in which the touch panel according to the present invention is applied to a multi-function mobile phone as a kind of the electronic device 1 has been described. However, the embodiment of the present invention is not limited to this. As the electronic device 1, in addition to a multi-function mobile phone, for example, a conventional mobile phone, a PDA (Personal Digital Assistant), a portable music player, an in-vehicle navigation device, a PND (Portable Navigation Device), a digital camera, a digital video camera, A portable game machine, a tablet, etc. are mentioned. The touch panel according to the present invention can also be suitably applied to these electronic devices 1.

(8) Regarding other configurations, it should be understood that the embodiments disclosed herein are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Accordingly, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

  The present invention can be used for, for example, a touch panel mounted on a multi-function mobile phone.

5: Touch panel 10: Panel member 10a: Operation surface 20: First electrode forming member 21: First substrate 22: First electrode 30: Second electrode forming member 31: Second substrate 32: Second electrode 50: Support member 60 : Control unit 63: Resistance detection unit 65: Input determination unit 66: Position determination unit 67: Pressing force determination unit

Claims (3)

A panel member having an operation surface and elastically deformable;
A plurality of first electrodes arranged in parallel to each other so as to be arranged in the X-axis direction on the opposite side of the operation surface of the panel member, and the electrical resistance changes according to a change in posture;
A plurality of second electrodes that face the plurality of first electrodes and are arranged in parallel to each other so as to be aligned in the Y-axis direction intersecting the X-axis direction, and the electrical resistance changes in accordance with a change in posture;
A resistance detector for detecting electrical resistances of the plurality of first electrodes and the plurality of second electrodes;
Based on the detection result by the resistance detection unit, an input determination unit that determines a pressing position in the XY coordinate system on the operation surface and a pressing force on the operation surface;
Bei to give a,
At least one of the first electrode and the second electrode is a touch panel that is formed so as to become narrower from the center in the extending direction toward both ends .   The touch panel according to claim 1, further comprising a frame-shaped support member that supports the panel member from a side on which the first electrode and the second electrode are provided.   The touch panel according to claim 2, wherein the support member is made of a material softer than a material constituting the panel member.

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