Input device

In an input device capable of reliably detecting, when an operator brings an operating body close to or into contact with an operation plane, absolute position information irrespective of a contact area size, third electrode arrays are disposed closer to the operation plane relative to second electrode arrays in a normal direction of the operation plane, the second electrode arrays have a portion protruding from the corresponding third electrode arrays when viewed in the normal direction, and assuming that a change amount of electrostatic capacitance between first and third electrode arrays occurred by an operation of the operating body is denoted by ΔC1 and a change amount of electrostatic capacitance between the first and second electrode arrays occurred by an operation of the operating body is denoted by ΔC2, a position of the operating body in the normal direction is calculated based on a ratio ΔC1/ΔC2.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an input device capable of reliably detecting, when an operator brings an operating body, such as a finger, close to or into contact with an operation plane, positional information of the operating body.

2. Description of the Related Art

In a capacitive input device disclosed in Japanese Unexamined Patent Application Publication No. 2015-166921, electrode portions positioned at opposite sides are determined as detection electrode portions, ground electrode portions are set between the detection electrode portions, and furthermore, a plurality of electrode portions positioned at a center are determined as driving detection portions. A coordinate position of a finger may be obtained by a difference of outputs of the detection electrode portions located at the opposite ends, and a vertical distance may be obtained by a sum of the outputs. When the vertical distance of the finger is smaller than a first threshold value, switching is performed such that a gap between the detection electrode portions is reduced, and when the finger further approaches, a touch detection mode is set.

A capacitive three-dimensional sensor disclosed in Japanese Unexamined Patent Application Publication No. 2016-091149 includes a first electrode body of a sheet shape having a patterned conductive film, a second electrode body of a sheet shape having a patterned conductive film, and a deformable body disposed between the first electrode body and the second electrode body. The deformable body includes an elastic layer substrate sheet and an elastic layer formed on one surface of the elastic layer substrate sheet. The deformable body is compressed and deformed when pressure is applied by the finger, and therefore, a distance between the first electrode body and the second electrode body is reduced. Accordingly, a pressing amount may be obtained by detecting a change in capacitance caused by the reduction of the distance.

The device disclosed in Japanese Unexamined Patent Application Publication No. 2018-005932 includes a detection surface, at least one capacitive sensor having a measurement electrode, a guard formed of an electrically conductive material disposed close to the measurement electrode, and electronic means for processing a signal emanating from the capacitive sensor. With this configuration, a distance from an object, a physical contact between the object and the detection surface, and downward pressing by the object may be detected when the object approaches.

A capacitance coupling type touch panel disclosed in Japanese Unexamined Patent Application Publication No. 2013-140635 includes a first transparent substrate, a second transparent substrate facing the first transparent substrate, and a plurality of coordinate electrodes that are disposed on the first transparent substrate and that detect a position coordinate. A floating electrode insulated from the plurality of coordinate electrodes is disposed on the second transparent substrate, and a gas layer and an interval-thickness control projecting pattern are disposed between the plurality of coordinate electrodes and the floating electrode. Accordingly, the floating electrode and the coordinate electrodes become close to each other since the floating electrode is pushed by a touch load obtained when a touch is performed by a resin pen or an insulating object, and therefore, capacitance between the floating electrode and the coordinate electrodes changes. Consequently, a position of the touch may be detected.

However, in the capacitive input devices disclosed in Japanese Unexamined Patent Application Publication Nos. 2015-166921, 2016-091149, 2018-005932, and 2013-140635, although a position of an operating body, such as a finger, on an operation plane may be detected, a shape or a size of the finger, for example, varies depending on an operator, and furthermore, a contact area to the operation plane varies depending on a contact pressure. Therefore, different capacitances are detected depending on sizes of contact areas when different fingers touch the same position, and accordingly, there arises a problem in that the same detection result may not be obtained in detections of positions in height in Japanese Unexamined Patent Application Publication Nos. 2015-166921, 2016-091149, and 2018-005932. Consequently, even though a detection of a relative position in a plane may be performed, it is difficult to detect an absolute position in height without influence of a contact area. Furthermore, the input device disclosed in Japanese Unexamined Patent Application Publication No. 2013-140635 may not perform a detection of a position in height in the first place.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides an input device capable of reliably detecting, when an operator brings an operating body, such as a finger, close to or into contact with an operation plane, information on an absolute position in a normal direction relative to the operation plane irrespective of a size of a contact area.

The present invention provides an input device including an operation plane on which an operating body is operated. The operation plane has a first direction and a second direction intersecting with the first direction. The input device includes a plurality of first electrode arrays that individually extend in the first direction and that are arranged with intervals interposed between the first electrode arrays, a plurality of second electrode arrays that individually extend in the second direction and that are arranged with intervals interposed between the second electrode arrays, and a plurality of third electrode arrays that individually extend in the second direction and that are arranged with intervals interposed between the third electrode arrays. The plurality of third electrode arrays are arranged closer to the operation plane relative to the plurality of second electrode array in a normal direction of the operation plane. The second electrode arrays have respective portions that protrude from the corresponding third electrode arrays when viewed in the normal direction. When the plurality of first electrode arrays are set as driving electrodes, the plurality of second electrode arrays and the plurality of third electrode arrays are individually set as reception electrodes, and when the plurality of first electrode arrays are set as reception electrodes, the plurality of second electrode arrays and the plurality of third electrode arrays are individually set as driving electrodes. Assuming that a change amount of electrostatic capacitance between the plurality of first electrode arrays and the plurality of third electrode arrays occurred by an operation of the operating body is denoted by ΔC1 and a change amount of electrostatic capacitance between the plurality of first electrode arrays and the plurality of second electrode arrays occurred by an operation of the operating body is denoted by ΔC2, a position of the operating body in the normal direction relative to the operation plane is calculated based on a ratio ΔC1/ΔC2 of the change amount ΔC1 and the change amount ΔC2.

Accordingly, an input device that is capable of reliably detecting, when an operator brings an operating body, such as a finger, close to or into contact with an operation plane, information on an absolute position in a normal direction relative to the operation plane irrespective of a size of a contact area (or a projection area projected to the operation plane), that has high detection accuracy, and that may suppress malfunction or non-operation may be provided. Examples of the contact with the operation plane include a pressing operation for displacing or deforming the operation plane. Also when the pressing operation is to be performed, information on an absolute position in the normal direction of the operation plane may be detected with high accuracy irrespective of a size of an area of the pressing.

In the description below, examples of the contact area include an area of projection to the operation plane obtained when the operating body is brought close to the operation plane and an area of pressing obtained when the pressing operation is performed.

In the input device according to the present invention, the ratio ΔC1/ΔC2 preferably has a smaller value as a distance of the operating body to the operation plane is reduced.

Since the ratio ΔC1/ΔC2 is set substantially in proportion to the distance between the operation plane and the operating body, influence of a size of the area of contact with the operation plane is suppressed and information on a position in the normal direction of the operation plane may be detected with high accuracy.

In the input device according to the present invention, the plurality of second electrode arrays are preferably arranged closer to the plurality of first electrode arrays relative to the plurality of third electrode arrays in the normal direction.

By this, sensitivity of a detection of a position in height of the operating body relative to the normal direction of the operation plane may be enhanced.

In the input device according to the present invention, the plurality of second electrode arrays and the plurality of third electrode arrays preferably have the same arrangement pitch in the first direction.

By this, the substantially proportional relationship of the ratio ΔC1/ΔC2 relative to the distance between the operation plane and the operating body may be ensured and information on a position in the normal direction of the operation plane may be detected with high accuracy while influence of a size of the area of contact with the operation plane is suppressed.

In the input device according to the present invention, centers of gravity of the second electrode arrays and centers of gravity of the third electrode arrays preferably coincide with each other in the first direction.

By this, both the second electrode arrays and the third electrode arrays may be viewed in the normal direction and electrostatic capacitance coupling is reliably performed between the corresponding electrode arrays and the operating body. Accordingly, since the change amounts ΔC1 and ΔC2 of the electrostatic capacitances are generated for the second electrode arrays and the third electrode arrays, not only a detection of a position in the normal direction of the operation plane with high accuracy but also an input device of high reliability that suppresses occurrence of malfunction and non-detection may be realized based on the ratio ΔC1/ΔC2.

In the input device according to the present invention, an elastic deformation layer is preferably formed closer to the operation plane relative to the plurality of third electrode arrays in the normal direction.

By this, a distance between the operating body and the third electrode arrays changes by a small amount when a pressing operation is performed, and a configuration capable of detecting an amount of the change may be realized. Furthermore, when the elastic deformation layer is disposed on a front surface, the elastic deformation layer may be easily replaced when being worn.

In the input device according to the present invention, an elastic deformation layer is preferably formed between the plurality of third electrode arrays and the plurality of second electrode arrays in the normal direction.

By this, a configuration in which a distance between the second electrode arrays and the third electrode arrays changes may be realized, and an amount of the change in distance caused by a pressing operation may be detected.

In the input device according to the present invention, when a pressing operation is performed using the operating body on the operation plane, a position of the operating body in height from the operation plane in the normal direction and a position of the operating body in the plane direction of the operation plane are preferably calculated.

By this, an input device capable of detecting a pressing position may be provided.

In the input device according to the present invention, when the operating body separates from the operation plane, a position of the operating body in height from the operation plane in the normal direction and a corresponding position of the operating body in the operation plane are preferably calculated.

By this, not only an operation performed by touching the operation plane but also a detection of an operation of the operating body in a state in which the operating body is not in contact with the operation plane and a detection at a time of a pressing operation may be performed.

In the input device according to the present invention, an in-plane position in the operation plane is preferably detected based on electrostatic capacitances generated between the plurality of first electrode arrays and the plurality of second electrode arrays.

By this, a position detection in a direction in the operation plane and a detection of a distance to the operation plane may be simultaneously operated, and therefore, a three-dimensional position detection may be performed in any of a state in which the operation plane is not touched, a state in which a touch operation is performed on the operation plane, and a state in which a pressing operation is performed.

According to the present invention, when an operator brings an operating body, such as a finger, close to or into contact with an operation plane, information on an absolute position in a normal direction relative to the operation plane may be reliably detected irrespective of a size of a contact area.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, input devices according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. Although a case where the present invention is applied to a touch panel having a capacitive sensor section formed on a planar substrate is described in the embodiments below, the input device of the present invention is not limited to this and is applicable to an input device having a curve-type capacitive sensor section or a device installed in the vicinity of a driver's seat, such as an installment panel of a vehicle, for example.

First Embodiment

FIG. 1is a plan view of a configuration of a capacitive sensor section20and third electrode arrays L31to L36in a capacitive input device10according to a first embodiment. Furthermore, the third electrode arrays L31to L36overlap the capacitive sensor section20as the arrangement relationship inFIG. 1. Note that, inFIG. 1, an elastic protection layer31, three adhesive layers32ato32c, a substrate20a, a panel body33, and wiring lines to the third electrode arrays L31to L36are omitted.FIG. 2is an enlarged view of a portion indicated by II inFIG. 1.FIG. 3is a sectional view of a configuration of the capacitive input device10that is cut off in a position of a line ofFIG. 1and viewed in an arrow direction.FIG. 4is a functional block diagram of the capacitive input device10according to the first embodiment.FIG. 5Ais a graph of the relationship between a height of an operating body relative to an upper surface of the third electrode arrays L31to L36(an axis of abscissae) and a change amount of capacitance (an axis of ordinates), andFIG. 5Bis a graph of the relationship between a height of the operating body relative to the upper surface of the third electrode arrays L31to L36(an axis of abscissae) and a ratio of a change amount of capacitance (an axis of ordinates).

InFIGS. 1 to 3, an X-Y-Z coordinate is illustrated as a reference coordinate. A Z1-Z2 direction corresponds to a thickness direction (a vertical direction) of the capacitive input device10, and an XY plane is perpendicular to the Z1-Z2 direction. An X1-X2 direction and a Y1-Y2 direction perpendicularly intersect with each other in the XY plane. In a description below, a state in which a Z2 side is viewed from a Z1 side in the Z1-Z2 direction is referred to as a plan view and a shape in plan view is referred to as a planar shape. The plan view corresponds to a view in a normal direction of an upper surface31a(an operation plane) of the elastic protection layer31. The upper surface31aof the elastic protection layer31serving as the operation plane has a Y1-Y2 direction as a first direction and an X1-X2 direction as a second direction in the plane. Although a case where the device is installed while the Z1-Z2 direction is set as a vertical direction is described hereinafter, the input device may be used in other attitudes.

As illustrated inFIG. 3, the capacitive input device10includes the capacitive sensor section20that detects input position information, the panel body33, the third electrode arrays L31to L36formed on the substrate20a, and the elastic protection layer31. The panel body33, the substrate20a, the third electrode arrays L31to L36, and the elastic protection layer31are arranged in this order from a side of the capacitive sensor section20to an input operation side (the Z1 direction inFIG. 3). The elastic protection layer31and the third electrode arrays L31to L36adhere to each other through the first adhesive layer32a, the substrate20aand the panel body33adhere to each other through the second adhesive layer32b, and furthermore, the panel body33and the capacitive sensor section20adhere to each other through the third adhesive layer32c.

An optical clear adhesive (OCA) is used for the three adhesive layers32a,32b, and32c, for example, or the three adhesive layers32a,32b, and32care formed by in-mold lamination (IML) or in-mold decoration (IMD).

The capacitive sensor section20includes (1) a substrate20band (2) first electrode arrays L11to L15, second electrode arrays L21to L26, bridge portions24, coupling portions25, wiring lines26, and terminal sections27that are formed on the substrate20b.

The elastic protection layer31(elastic deformation layer) is formed in a rectangular shape so as to cover the capacitive sensor section20in plan view, and the upper surface31aserves as an operation plane of the capacitive input device10. Operations are performed on the operation plane using an operating body, such as a finger or a hand of the operator. The elastic protection layer31(the elastic deformation layer) is disposed near the operation plane relative to the first electrode array L11to L15and the second electrode array L21to L26and near the operation plane relative to the third electrode array L31to L36.

Examples of the operating body include a finger or a hand of an operator and a stylus or a touch pen that is compatible with capacitive input devices. When the input device is to be applied to a vehicle, the input device may be disposed on a steering wheel for operating the vehicle, for example. In this case, a hand of a driver holding the steering wheel corresponds to the operating body. The input device may detect a position of the hand on the steering wheel and a degree of strength of grabbing by the hand. Furthermore, when the input device is disposed on seating face or a seat back portion of the vehicle, a back, hips, or legs of a person on the seat corresponds to the operating body so that a body state, such as stability of seating of the person on the seat, may be detected.

The elastic protection layer31is configured by non-conductive material that may be elastically deformed when force is vertically applied by an operation using the operating body. Examples of the material include silicone rubber, urethane rubber, acrylic rubber, and fluorine-contained rubber. Properties of the elastic protection layer31, such as a thickness, light transparency, and a color, may be appropriately selected in accordance with the specification of the capacitive input device10.

A colored opaque decorative layer may be formed on a back surface (a surface in the Z2 direction ofFIG. 1) of the elastic protection layer31in accordance with the specification of the capacitive input device10. The decorative layer is disposed by printing or the like such that the decorative layer overlaps a non-input region16disposed outside an input region15of the capacitive sensor section20in plan view.

The panel body33has a rectangular shape so as to cover the capacitive sensor section20in plan view. The panel body33is configured by non-conductive material having rigidity. Examples of the material include polycarbonate resin, polymethyl methacrylate resin, other acrylic resins, and glass. As described hereinafter, a thickness of the panel body33is set such that the second electrode arrays L21to L26and the third electrode arrays L31to L36are disposed with a predetermined interval in the vertical direction. Properties of the panel body33, such as light transparency and a color, may be appropriately selected in accordance with specification of the capacitive input device10.

<First Electrode Array and Second Electrode Array>

As illustrated inFIG. 1, a plurality of first electrodes21and a plurality of second electrodes22are arranged in the input region15of the capacitive sensor section20.

The capacitive sensor section20includes the substrate20band a plurality of first electrodes21, a plurality of second electrodes22, and the plurality of wiring lines26that are formed on a substrate surface (an upper surface on a Z1 side) of the substrate20b. The first electrodes21and the second electrodes22are formed in the input region15and have a pad shape having a plane extending in the XY plane.

The first electrodes21are disposed in the Y1-Y2 direction (the first direction) with intervals. The first electrodes21that are adjacent to each other in the Y1-Y2 direction are coupled with each other by the narrow coupling portions25to form a first electrode array. As illustrated inFIG. 2, five first electrode arrays L11to L15are arranged in the X1-X2 direction (the second direction) with intervals.

The second electrodes22are disposed in the X1-X2 direction (the second direction) with intervals. The second electrodes22that are adjacent to each other in the X1-X2 direction are coupled with each other by the narrow bridge portions24to form a second electrode array. In the configuration illustrated inFIGS. 1 and 2, six second electrode arrays L21to L26are arranged in the Y1-Y2 direction (the first direction) with intervals.

As illustrated inFIGS. 1 and 2, the plurality of first electrode arrays L11to L15and the plurality of second electrode arrays L21to L26intersect with each other. As illustrated inFIG. 3, in each portion where the coupling portion25and the bridge portion24intersect with each other, an intersecting portion insulating layer35is disposed to cover the coupling portion25, and the bridge portion24is formed so as to stride the coupling portion25and the intersecting portion insulating layer35. The first electrodes21are coupled to each other through the coupling portions25, and the second electrodes22disposed so as to sandwich the coupling portions25in the X1-X2 direction are coupled to each other through the bridge portions24. In this way, the first electrodes21and the second electrodes22are insulated from each other.

As illustrated inFIG. 1, the plurality of wiring lines26coupled to the first electrodes21and the second electrodes22are formed in the non-input region16of the substrate20b. The plurality of wiring lines26are drawn in the non-input region16of the substrate20band coupled to the terminal portions27to be coupled to an external circuit.

The substrate20bis formed of non-conductive resin material of a film shape, and for example, translucent resin material, such as polycarbonate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, cyclic polyolefin, or polymethyl methacrylate resin, is used. The first electrodes21, the second electrodes22, and the coupling portions25are translucent conductive material, such as indium tin oxide (ITO), SnO2, or ZnO, by thin film method, such as spattering or evaporation. Furthermore, the bridge portions24are formed by metal material, such as Cu, Ag, or Au, alloy, such as CuNi or AgPd, or conductive oxide material, such as ITO. As the wiring lines26and the terminal portions27, metal material, such as Cu, Ag, or Au, or conductive oxide material, such as ITO, may be used.

As illustrated inFIG. 1, the six third electrode arrays L31to L36are arranged in the input region15of the capacitive input device10. The third electrode arrays L31to L36are formed on the substrate20a(FIG. 3).

The third electrode arrays L31to L36are formed in respective lines having the same width extending in the X1-X2 direction (the second direction). In the configuration illustrated inFIG. 1, the six third electrode arrays L31to L36are arranged in the Y1-Y2 direction (the first direction) with intervals.

The third electrode arrays L31to L36overlap the second electrode arrays L21to L26in plan view, respectively, and furthermore, overlap the bridge portions24that couple the plurality of second electrodes22forming the individual second electrode arrays to one another in plan view.

Furthermore, the third electrode arrays L31to L36are disposed in the Y1-Y2 direction with the same arrangement pitch as the second electrode arrays L21to L26, and centers of gravity of the third electrode arrays L31to L36coincide with the corresponding second electrode arrays in the Y1-Y2 direction.

As illustrated inFIGS. 1 and 2, the individual third electrode arrays L31to L36have substantially the same width as the bridge portions24in the Y1-Y2 direction. Therefore, in plan view, the individual second electrodes22of the second electrode arrays have respective portions that protrude from the corresponding third electrode arrays. Since at least certain amount of protrusion is ensured, the third electrode arrays interposed between the second electrode arrays and the operating body in the vertical direction do not disturb a change in capacitance, and therefore, a detection may be reliably performed by the second electrode arrays.

As illustrated inFIG. 3, in the vertical direction, the third electrode arrays L31to L36are arranged on the capacitive sensor section20through the panel body33, the second adhesive layer32b, and the substrate20a, and are disposed closer to the upper surface31aof the elastic protection layer31relative to the capacitive sensor section20including the second electrode arrays.

The substrate20aon which the third electrode arrays L31to L36are disposed is formed of, similarly to the substrate20bin the capacitive sensor section20, a non-conductive resin material of a film shape. The third electrode arrays L31to L36are formed of, similarly to the first electrodes21, the second electrodes22, and the coupling portions25, translucent conductive material, such as ITO, SnO2, or ZnO.

Although not illustrated, a plurality of wiring lines individually coupled to the third electrode arrays L31to L36are formed in the non-input region16of the substrate20a. The plurality of wiring lines are drawn in the non-input region16to be coupled to terminal portions (not illustrated) to be connected to an external circuit.

When the five first electrode arrays L11to L15are set as driving electrodes, the six second electrode arrays L21to L26and the six third electrode arrays L31to L36are individually set as reception electrodes. When the five first electrode arrays L11to L15are set as reception electrodes, the six second electrode arrays L21to L26and the six third electrode arrays L31to L36are individually set as driving electrodes. In any of these configurations, electrostatic capacitances are formed between the individual first electrode arrays L11to L15and the individual second electrode arrays L21to L26. The electrostatic capacitances are changed when electrostatic capacitances formed between the operating body and the reception electrodes are coupled by causing the operating body to move close to the operation plane or to move away from the operation plane. A position of the operating body in the operation plane is detected based on a position where the change in electrostatic capacitance occurs in the XY plane.

As illustrated inFIG. 4, the first electrode arrays L11to L15, the second electrode arrays L21to L26, and the third electrode arrays L31to L36are coupled to a multiplexer41, and a driving circuit42and a detection circuit42are coupled to the multiplexer41. The multiplexer41, the driving circuit42, and the detection circuit43are coupled to a controller44(a control circuit) that controls processes of the multiplexer41, the driving circuit42, and the detection circuit43.

The multiplexer41causes the driving circuit42to be coupled to electrode arrays set as driving electrodes selected from among the first electrode arrays L11to L15, the second electrode arrays L21to L26, and the third electrode arrays L31to L36and causes the detection circuit43to be coupled to electrode arrays set as reception electrodes. A result of detection performed by the detection circuit43is stored in a storage section included in the controller44, and the controller44executes calculations of a ratio of the electrostatic capacitance and the like based on the detection result.

For example, when a voltage is applied from the driving circuit42to the first electrode arrays L11to L15serving as driving electrodes in turn, current is supplied to the individual second electrode arrays L21to L26and the individual third electrode arrays L31to L36serving as reception electrodes at a timing of rising and falling of rectangle waves, and the detection currents are supplied to the detection circuit43. The detection circuit43converts the detection currents into voltages, integrates and amplifies the voltages, and performs A/D conversion so as to output a detection result to the controller44.

When the operator brings the operating body, such as a finger or a hand, into contact with or close to the input region15of the upper surface31a(the operation plane) of the elastic protection layer31to perform an input operation, in an electrode array positioned proximal to the operating body among the second electrode arrays L21to L26, electrostatic capacitance formed between the second electrode22and the operating body is coupled to electrostatic capacitance generated between the second electrode22and the first electrode21that are adjacent to each other. Therefore, a value of electrostatic capacitance detected in the second electrode22with which the operating body is in contact or to which the operating body moves close is changed. As described below, a position (a height position) in the normal direction of the operation plane is detected based on an amount ΔC2 of this change.

When the operator brings the operating body, such as a finger or a hand, into contact with or close to the input region15of the upper surface31a(the operation plane) of the elastic protection layer31, electrostatic capacitance formed between an electrode array that is proximal to the operating body selected from among the third electrode arrays L31to L36(a proximal third electrode array) and the operating body is coupled to electrostatic capacitance generated between one of the first electrode arrays L11to L15intersecting with the proximal third electrode array in plan view and the proximal third electrode array. Therefore, a value of electrostatic capacitance detected in the proximal third electrode array (one of the third electrode arrays L31to L36that is into contact with the operating body or that is close to the operating body) is changed. As described below, a position (a height position) in the normal direction of the operation plane is detected based on a change amount ΔC1.

Here, as illustrated inFIG. 3, the second electrode arrays L21to L26and the third electrode arrays L31to L36are disposed in a lower portion and an upper portion, respectively, with the substrate20a, the second adhesive layer32b, the panel body33, and the third adhesive layer32cthat are formed of non-conductive material interposed therebetween. In other words, in the vertical direction, the second electrode arrays L21to L26and the third electrode arrays L31to L36are disposed with a certain gap through the non-conductive material. The certain gap (the gap between the second electrode arrays and the third electrode arrays) is larger than a gap between the first electrode arrays L11to L15and the second electrode arrays L21to L26in the vertical direction, and is predetermined times as large as the gap between the first electrode arrays L11to L15and the second electrode arrays L21to L26.

With this configuration, assuming that a change amount of electrostatic capacitance between the first electrode arrays L11to L15and the third electrode arrays L31to L36occurred by an operation of the operating body is represented by ΔC1, a change amount of electrostatic capacitance between the first electrode arrays L11to L15and the second electrode arrays L21to L26occurred by an operation of the operating body is represented by ΔC2, as illustrated inFIG. 5A, the two change amounts ΔC1 and ΔC2 are differently changed relative to a distance (an axis of abscissae (a unit of mm) ofFIG. 5A) of the operating body to an upper surface of the third electrode arrays L31to L36(Height Based on the top electrode) depending on a gap in the vertical direction between the second electrode arrays L21to L26and the third electrode arrays L31to L36. Here, inFIG. 5A, the change amount ΔC1 is represented by a dotted line including white circles and the change amount ΔC2 is represented by a solid line including black circles.

Furthermore, when a ratio ΔC1/ΔC2 of the two change amounts ΔC1 and ΔC2 is plotted relative to the distance of the operating body to the upper surface of the third electrode arrays, as illustrated inFIG. 5B, the linear relationship is obtained and the ratio is reduced as the distance of the operating body to the operation plane is reduced. Therefore, based on this straight line, a position in height from the operation plane in the Z1-Z2 direction (the normal direction relative to the operation plane) and a position in the operation plane may be accurately detected (calculated). In particular, use of the ratio ΔC1/ΔC2 enables elimination of influence of a size of an area of the operating body in a plane direction of the operation plane, and accordingly, an absolute value of a position in height from the operation plane and an absolute value of a corresponding position in the operation plane (an in-plane position) may be accurately detected.

Here, results of simulation in a configuration in which sizes of individual layers are set as below are illustrated inFIGS. 5A and 5B. Thicknesses correspond to sizes in the Z1-Z2 direction.

Elastic protection layer31: a thickness of 1.0 mm;

First adhesive layer32a: a thickness of 0.1 mm;

Third electrode arrays L31to L36: a width in the Y1-Y2 direction of 0.20 mm and a thickness of 20 nm;

Substrate20a: a thickness of 0.05 mm;

Second adhesive layer32b: a thickness of 0.1 mm;

Panel body33: a thickness of 3.00 mm;

Third adhesive layer32c: a thickness of 0.175 mm (max);

First electrode arrays L11to L15: a diagonal length of 6.20 mm (lengths in the X1-X2 direction and the Y1-Y2 direction) and a thickness of 20 nm;

Second electrode arrays L21to L26: a diagonal length of 6.20 mm (lengths in the X1-X2 direction and the Y1-Y2 direction) and a thickness of 20 nm;

Substrate20b: a thickness of 0.05 mm.

Hereinafter, a modification will be described. In the foregoing embodiment, the second electrode arrays L21to L26are arranged in the same layer as the first electrode arrays L11to L15, stride over the first electrode arrays L11to L15in the bridge portions24, and are positioned closer to the first electrode arrays L11to L15relative to the third electrode arrays L31to L36in the vertical direction (the normal direction of the operation plane). Meanwhile, the second electrode arrays L21to L26may be disposed on an upper side or a lower side of the first electrode arrays L11to L15in the vertical direction as long as the second electrode arrays L21to L26are positioned closer to the first electrode arrays L11to L15relative to the third electrode arrays L31to L36in the vertical direction.

Furthermore, shapes of the second electrode arrays and the third electrode arrays in plan view are not limited to the shapes described in the foregoing embodiment as long as centers of gravity of the second electrode arrays and the corresponding third electrode arrays that correspond to each other coincide with each other in a direction in which the first electrode arrays L11to L15individually extend (the Y1-Y2 direction (the first direction)) and the second electrode arrays protrude from the third electrode arrays by a predetermined amount or more in plan view. For example, third electrode arrays L131to L136having a planar shape as illustrated inFIG. 6may be used instead of the third electrode arrays L31to L36in the foregoing embodiment. Here,FIG. 6is a plan view of the capacitive sensor section20according to the first embodiment to which the third electrode arrays L131to L136according to a first modification are applied. InFIG. 6, only the third electrode array L132is represented by a dotted line among the third electrode arrays L131to L136so that the positional relationships with bridge portions24are clearly illustrated.

In each of the third electrode arrays L131to L136illustrated inFIG. 6, a plurality of third electrodes123aare disposed with intervals in the X1-X2 direction and are coupled to one another by narrow coupling portions123bextending in the X1-X2 direction. The third electrodes123ahave a shape similar to that of the second electrodes22in plan view and are disposed such that centers of gravity thereof coincide with those of the corresponding second electrodes22. Furthermore, the third electrodes123aare shaped small such that the corresponding second electrodes22protrude by a predetermined amount or more in plan view. Furthermore, the coupling portions123bhave substantially the same width as the bridge portions24so as to overlap with the bridge portions24in plan view.

As for the configuration in which the centers of gravity of the second electrode arrays and the centers of gravity of the corresponding third electrode arrays coincide with each other in a direction in which the first electrode arrays L11to L15individually extend (the Y1-Y2 direction (the first direction)), as illustrated inFIG. 7, the third electrode arrays may be shifted from the corresponding second electrode arrays in the X1-X2 direction. Here,FIG. 7is a plan view of the capacitive sensor section20according to the first embodiment to which third electrode arrays L231to L236according to a second modification are applied. InFIG. 7, only the third electrode array L232is represented by a dotted line among the third electrode arrays L231to L236so that the positional relationships with bridge portions24are clearly illustrated.

In the third electrode arrays L231to L236illustrated inFIG. 7, a plurality of third electrodes223aare disposed with intervals in the X1-X2 direction and are coupled to one another by narrow coupling portions223bextending in the X1-X2 direction. The third electrodes223ahave the same shape as the second electrodes22in plan view and are disposed in intermediate positions between the adjacent second electrodes2in the X1-X2 direction. The coupling portions223bhave substantially the same width as the bridge portions24so as to overlap with the bridge portions24in plan view. According to this configuration, although the third electrodes223aand the second electrodes22have the same area, an amount of protrusion of the second electrodes22is ensured to be equal to or larger than the predetermined amount in plan view. Accordingly, large reception electrodes may be ensured in both the second electrode arrays and the third electrode arrays and a change in electrostatic capacitance may be more reliably detected, and therefore, as with the first embodiment, an absolute value of a position in height in a normal direction of the operation plane may be accurately detected based on the change amount of the electrostatic capacitance and a position in the operation plane may be accurately detected based on the position where the electrostatic capacitance is changed.

Second Embodiment

FIG. 8is a sectional view of a configuration of a capacitive input device310according to a second embodiment. The capacitive input device310of the second embodiment has the same components as the first embodiment except that an elastic layer331and a protection layer336are disposed instead of the elastic protection layer31of the first embodiment. Components the same as those in the first embodiment are denoted by the same reference numerals.FIG. 8is a sectional view in a position corresponding toFIG. 3.FIG. 9Ais a graph of the relationship between a height of an operating body relative to an upper surface of third electrode arrays (an axis of abscissae) and a change amount of capacitance (an axis of ordinates), andFIG. 9Bis a graph of the relationship between a height of the operating body relative to the upper surface of the third electrode arrays (an axis of abscissae) and a ratio of a change amount of capacitance (an axis of ordinates). Also in the second embodiment, as with the first embodiment, electrostatic capacitances are formed between individual first electrode arrays L11to L15and individual second electrode arrays L21to L26. The electrostatic capacitances are changed when electrostatic capacitances formed between an operating body and reception electrodes are coupled by causing the operating body to move close to an operation plane or to move away from the operation plane. A position of the operating body in height in a normal direction of the operation plane is detected based on an amount of the change and position detection in the operation plane (an XY plane) is performed based on a position where the change in electrostatic capacitance occurs.

As illustrated inFIG. 8, in the capacitive input device310of the second embodiment, an elastic layer331(an elastic deforming layer), a third electrode array L332disposed on a substrate320a, and a protection layer336are disposed and formed on a panel body33in this order toward an upper side. Although not illustrated, in the second embodiment, six third electrode arrays having the same configuration as the third electrode arrays L31to L36of the first embodiment extend in the X1-X2 direction, and the third electrode array L332illustrated inFIG. 8corresponds to the third electrode array L32of the first embodiment.

The protection layer336and the third electrode array L332adhere to each other through a first adhesive layer332a, the substrate320aand the elastic layer331adhere to each other through a second adhesive layer332b, and furthermore, the elastic layer331and the panel body33adhere to each other through a third adhesive layer332c. The capacitive sensor section20and the panel body33have the same configuration as those of the first embodiment and adhere to each other through a third adhesive layer32c. The elastic layer331is disposed between the third electrode array L332and both the first electrode arrays L11to L15and the second electrode arrays L21to L26.

The elastic layer331, the substrate320a, and the three adhesive layers332ato332care configured by the same material as the elastic protection layer31, the substrate20a, and the three adhesive layers32ato32c, respectively. A thickness of the elastic layer331is set in accordance with pressure estimated by the capacitive input device310.

The protection layer336is configured by non-conductive material having rigidity, and examples of the material include polycarbonate resin, polymethyl methacrylate resin, other acrylic resins, and glass.

Here, sizes of the individual layers are set as follows.

Protection layer336: a thickness of 0.5 mm;

First adhesive layer332a: a thickness of 0.1 mm;

Third electrode arrays: a width of 0.20 mm in a Y1-Y2 direction and a thickness of 20 nm;

Substrate320a: a thickness of 0.05 mm;

Second adhesive layer332b: a thickness of 0.1 mm;

Elastic layer331: a thickness of 2.5 mm;

Third adhesive layer332c: a thickness of 0.1 mm;

Panel body33: a thickness of 3.00 mm;

Third adhesive layer32c: a thickness of 0.175 mm (max);

First electrode arrays L11to L15: a diagonal length of 6.20 mm (lengths in the X1-X2 direction and the Y1-Y2 direction) and a thickness of 20 nm;

Second electrode arrays L21to L26: a diagonal length of 6.20 mm (lengths in the X1-X2 direction and the Y1-Y2 direction) and a thickness of 20 nm;

Substrate20b: a thickness of 0.05 mm.

With this configuration, when downward pressure is applied to an upper surface336aof the protection layer336serving as the operation plane, elastic deformation occurs such that the elastic layer331contracts downward. Therefore, as illustrated inFIGS. 9A and 9B, the operating body reaches a negative region of the axis of abscissae that is lower than a position before the pressing operation is performed.

As illustrated inFIG. 9A, change amounts ΔC1 and ΔC2 of capacitance are differently changed relative to a distance (an axis of abscissae (a unit of mm) ofFIG. 9A) of the operating body to an upper surface of the third electrode arrays (Height Based on the top electrode). Furthermore, a ratio ΔC1/ΔC2 of the ΔC1 and ΔC2 has the linear relationship in the negative region and a positive region of the axis of abscissae as illustrated inFIG. 9B. Therefore, the ratio is reduced as the distance of the operating body to the operation plane is reduced, and this tendency is the same in the negative region. Here, inFIG. 9A, the change amount ΔC1 is represented by a dotted line including white circles and the change amount ΔC2 is represented by a solid line including black circles.

Accordingly, in any of a state in which the operating body is not in contact with the operation plane, a state in which the operating body is in contact with the operation plane, and a state in which pressure is applied to the operation plane, a height position (a position in the normal direction relative to the operation plane) from the operation plane in the Z1-Z2 direction (a position in the normal direction relative to the operation plane) may be reliably detected based on the straight line. Use of the ratio ΔC1/ΔC2 enables elimination of influence of a size of an area of the operating body in a plane direction of the operation plane, and accordingly, an absolute value of a position in height from the operation plane (a position in the normal direction relative to the operation plane) may be accurately calculated. Furthermore, in addition to a corresponding position (in-plane position) in the operation plane in the capacitive sensor section20, an absolute position of a three-dimensional coordinate relative to the operation plane may be accurately calculated.

Although the present invention is described with reference to the foregoing embodiments, the present invention is not limited to the foregoing embodiments and may be altered or modified within the object of improvement or the scope of the invention.

As described above, the input device according to the present invention is effective in that information on an absolute position in a normal direction relative to an operation plane may be reliably detected irrespective of a size of a contact area when an operator brings an operating body, such as a finger, close to or into contact with the operation plane.