Position detection device, input device, and position detection method

Abstract

Provided are a position detection device, an input device, and a position detection method capable of correcting the two-dimensional coordinates of an object on an operation surface according to the degree of contact or proximity.　The position detection device includes: a detection unit that that detects the degree of contact or proximity of an object with or to an operation surface at a plurality of detection positions on the operation surface and outputs a plurality pieces of detection data expressing the degree at the plurality of detection positions; a coordinate calculation unit that calculates, on the basis of the plurality pieces of detection data detected by the detection unit, spatial coordinates of the object in a spatial coordinate system having a first axis and a second axis included in a plane parallel to the operation surface and a third axis; and a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinates calculated by the coordinate calculation unit on the basis of the coordinate value of the third axis in the spatial coordinates.

Description

[Technical Field]

[0001] The present disclosure relates to a position detection device, an input device, and a position detection method. [Background technology]

[0002] Conventionally, there has been an input device that includes a proximity sensor that detects a non-contact hover operation on a touch surface and a touch sensor that detects a touch operation that contacts the touch surface, and corrects the offset between the position of the hover operation and the position of the touch operation on the touch surface (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2021 / 0011604 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional input devices correct the offset between the position of a hover operation and the position of a touch operation detected by separate sensors, but do not correct the two-dimensional coordinates of an object on the operation surface according to the degree of proximity of the object, such as a hand, performing the hover operation to the operation surface.

[0005] Therefore, an object of the present invention is to provide a position detection device, an input device, and a position detection method that are capable of correcting the two-dimensional coordinates of an object on an operation surface according to the degree of contact or proximity. [Means for solving the problem]

[0006] A position detection device according to an embodiment of the present disclosure includes a detection unit that detects the degree of contact or proximity of an object to an operation surface at a plurality of detection positions on the operation surface and outputs a plurality of detection data representing the degree at the plurality of detection positions; a coordinate calculation unit that calculates, based on the plurality of detection data detected by the detection unit, spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis included in a plane parallel to the operation surface; and a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinates based on the coordinate value of the third axis in the spatial coordinates calculated by the coordinate calculation unit. [Effects of the Invention]

[0007] It is possible to provide a position detection device, an input device, and a position detection method that are capable of correcting the two-dimensional coordinates of an object on an operation surface according to the degree of contact or proximity. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of a configuration of an input device 100 according to an embodiment. [Figure 2] 10 is a diagram illustrating the deviation between the center of gravity coordinates and the position of the fingertip FT. FIG. [Figure 3] 10 is a diagram illustrating deviations of X and Y coordinates as the center of gravity coordinates calculated by the coordinate calculation unit 130. FIG. [Figure 4] FIG. 10 is a flowchart showing the processing executed by a coordinate calculation unit 130 and a coordinate correction unit 140. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments to which the position detection device, input device, and position detection method of the present disclosure are applied will be described.

[0010] <Embodiment> 1 is a diagram showing an example of the configuration of an input device 100 according to an embodiment of the present invention, showing an operation target device 10 that is a target of input operation by the input device 100.

[0011] The following description will be given by defining an XYZ coordinate system. As an example, the origin O of the XYZ coordinates is the center of the operation surface 101A, and the XY coordinates of the origin O coincide with the coordinates of the center of the sensor unit 110. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to each other. The XYZ coordinate system is an example of a spatial coordinate system. The X axis is an example of a first axis, the Y axis is an example of a second axis, and the Z axis is an example of a third axis. The X coordinate, Y coordinate, and Z coordinate in the XYZ coordinate system are examples of spatial coordinates. The X coordinate is an example of a coordinate value of the first axis, the Y coordinate is an example of a coordinate value of the second axis, and the Z coordinate is an example of a coordinate value of the third axis.

[0012] In the following, for the sake of convenience, the -Z direction side may be referred to as the lower side or bottom, and the +Z direction side as the upper side or top, but this does not represent a universal vertical relationship. Furthermore, the top side of a certain component is the front side, and the bottom side is the back side. Furthermore, a plan view refers to a view from the XY plane. In the following, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand.

[0013] The input device 100 includes a cover 101, a sensor unit 110, and a position detection device 100A. The position detection method of the embodiment is a method for detecting the position of an operation input performed by the position detection device 100A. Below, a description will be given of a mode in which a user of the input device 100 performs an input operation on the operation surface 101A using a fingertip FT. The fingertip FT is an example of an object that touches or is close to the operation surface 101A. However, the user may perform an input operation using a part of the body other than the fingertip FT.

[0014] The input device 100 detects the spatial coordinates of an input operation performed by the user's fingertip FT, corrects the X and Y coordinates (XY coordinates) according to the Z coordinate, and outputs the corrected XY coordinates and Z coordinate. The input device 100 may be used to remotely control the operation target device 10, or may be provided integrally with the operation target device 10. The input device 100 may be portable, or may be fixedly installable on a wall surface or the like.

[0015] Here, a description will be given of a configuration in which the cover 101 and the sensor unit 110 are transparent, assuming that a display panel (display device) such as a liquid crystal or organic EL (Electroluminescence) display is disposed below the input device 100. However, if, for example, a display panel is not disposed, the cover 101 and the sensor unit 110 do not have to be transparent. Buttons and the like of a GUI (Graphical User Interface) displayed by a display panel disposed on the back side of the sensor unit 110 can be seen through the cover 101 and the sensor unit 110.

[0016] <Cover 101 Configuration> The cover 101 is disposed on the front side of the sensor unit 110 and is, for example, a rectangular plate-like member in a plan view. The cover 101 is provided as a top panel that covers the top surface of the input device 100. The top surface of the cover 101 is the operation surface 101A. The operation surface 101A has a plurality of detection positions corresponding to the plurality of electrodes 112 of the sensor unit 110. As described above, as an example, the origin O of the XYZ coordinate system is the center of the operation surface 101A, and the XY plane including the X and Y axes coincides with the operation surface 101A. However, the origin O of the XYZ coordinate system does not have to coincide with the center of the operation surface 101A. In this case, the XY plane including the X and Y axes is a plane parallel to the operation surface 101A.

[0017] A user of the input device 100 can perform an input operation by touching (contacting) the operation surface 101A of the cover 101 with a fingertip FT, or by bringing the fingertip FT close to the operation surface 101A without touching it (non-contacting). Such a cover 101 is made of, for example, transparent glass or resin.

[0018] Hereinafter, an input operation of touching the operation surface 101A will be referred to as a “touch input,” and an input operation of approaching without contact will be referred to as a “hover input.” Also, “approach” refers to the fingertip FT approaching the operation surface 101A to such an extent that a change in the capacitance of the sensor unit 110 that can be detected by the position detection device 100A occurs.

[0019] <Configuration of sensor unit 110> The sensor unit 110 has a substrate 111 and a plurality of electrodes 112 provided on the upper surface of the substrate 111. The sensor unit 110 is a capacitance sensor provided to detect a touch input or a hover input to a GUI button based on a change in capacitance of the plurality of electrodes 112. The capacitance of the electrodes 112 is an example of a physical quantity that indicates the degree of contact or proximity of the fingertip FT.

[0020] The substrate 111 may be made of any transparent insulating material, and may be, for example, a transparent substrate made of polyimide. A plurality of electrodes 112 are arranged on the upper surface of the substrate 111. The substrate 111 is not limited to a transparent substrate made of polyimide, and a substrate made of other materials may also be used. Furthermore, a plurality of electrodes 112 may be arranged on the lower surface of the substrate 111.

[0021] The multiple electrodes 112 are arranged in a matrix in the X and Y directions. While Fig. 1 shows 12 electrodes 112 arranged in three rows in the Y direction and four columns in the X direction, any number of electrodes 112 may be used as long as there is a plurality of electrodes 112. A configuration may be adopted in which one or more electrodes 112 are arranged corresponding to one GUI button. Furthermore, the electrodes 112 may be linear electrodes, with multiple electrodes extending in each of the X and Y directions.

[0022] For example, the electrodes 112 are independent of one another and connected to the position detection device 100A via wiring (not shown) that runs between them in a plan view. The electrodes 112 are made of transparent electrodes such as ITO (Indium Tin Oxide). If no display panel is disposed on the back side of the sensor unit 110, the electrodes 112 may be metal plates or the like.

[0023] The detectable range of the electrodes 112 is, for example, within approximately 30 mm to approximately 50 mm from the operation surface 101A. The electrodes 112 can detect that the fingertip FT is in proximity within approximately 30 mm to approximately 50 mm from the operation surface 101A. The sensor unit 110 can also detect that the fingertip FT is touching the operation surface 101A. The capacitance of each electrode 112 of the sensor unit 110 is detected by the detection unit 120 of the position detection device 100A. The capacitance of each electrode 112 changes depending on the touch input or hover input.

[0024] <Configuration of position detection device 100A> The position detection device 100A includes a detection unit 120, a coordinate calculation unit 130, and a coordinate correction unit 140. The coordinate correction unit 140 includes a correction degree setting unit 141 and a correction calculation unit 142. Here, as an example, a configuration will be described in which the detection unit 120 is configured with an IC (Integrated Circuit), and the coordinate calculation unit 130 and the coordinate correction unit 140 are configured with a microcomputer 150; however, the configuration is not limited to this. The microcomputer 150 is realized by a computer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an input / output interface, an internal bus, and the like. The coordinate calculation unit 130, the coordinate correction unit 140, the correction degree setting unit 141, and the correction calculation unit 142 are functional blocks representing the functions of a program executed by the microcomputer 150.

[0025] The detection unit 120 detects the capacitance of the plurality of electrodes 112 of the sensor unit 110 and outputs a plurality of detection data representing the capacitance at a plurality of detection positions on the operation surface 101A. The detection unit 120 converts the capacitance (analog value) of the plurality of electrodes 112 input from the sensor unit 110 into digital data and outputs the detection data representing the capacitance in digital values to the coordinate calculation unit 130. Note that, although a detailed description will be omitted here, the detection unit 120 may also function as a selection unit that applies voltages to the 12 electrodes 112 arranged in 3 rows and 4 columns in a time-division manner to select them in the X direction and the Y direction.

[0026] The coordinate calculation unit 130 calculates the XY coordinates of the touch input or hover input based on the detection data input from the detection unit 120, and also calculates the Z coordinate of the touch input or hover input. Various methods can be used to calculate the XY coordinates, such as a method of calculating centroid coordinates or a method of calculating the position of the peak where the capacitance is greatest. Here, as an example, a description will be given of a method of calculating, as the XY coordinates, the centroid of the positions of the multiple electrodes 112 (e.g., the centroid of the positions of the 12 electrodes 112) corresponding to multiple detection data (e.g., 9 out of 12 detection data) with large amounts of change in capacitance among all detection data obtained from the capacitances of all the electrodes 112. As an example, the center position of the XY coordinates of each electrode 112 may be used as the position of each electrode 112.

[0027] Furthermore, there are various methods for calculating the Z coordinate, but as an example, a form will be described here in which the coordinate calculation unit 130 calculates, as the Z coordinate of the fingertip FT on the operation surface 101A, a distance corresponding to the capacitance represented by detection data with the largest amount of change in capacitance among all detection data obtained from the capacitances of all electrodes 112. The coordinate calculation unit 130 outputs data representing the calculated XY coordinates and Z coordinate to the coordinate correction unit 140. The coordinate calculation unit 130 also outputs data representing the Z coordinate to the operation target device 10. Calculating the Z coordinate in this manner corresponds to calculating the Z coordinate based on a plurality of detection data input from the detection unit 120.

[0028] The coordinate correcting unit 140 includes a correction degree setting unit 141 and a correction calculating unit 142. The coordinate correcting unit 140 corrects the X and Y coordinates based on the Z coordinate calculated by the coordinate calculating unit .

[0029] The correction degree setting unit 141 determines the correction degree for correcting the XY coordinates based on the Z coordinate input from the coordinate calculation unit 130, and outputs the degree to the correction calculation unit 142. A specific method for determining the correction degree will be described later.

[0030] The correction calculation unit 142 corrects the X and Y coordinates input from the coordinate calculation unit 130 using the correction degree input from the correction degree setting unit 141. In this way, the corrected X and Y coordinates are calculated by the correction calculation unit 142. The correction calculation unit 142 outputs the corrected X and Y coordinates to the operation target device 10. A specific method for calculating the corrected X and Y coordinates will be described later.

[0031] <Displacement between the center of gravity coordinates and the fingertip FT position> 2 is a diagram illustrating a deviation between the barycentric coordinates and the position of the fingertip FT. Here, a deviation between the barycentric coordinates and the position of the fingertip FT that may occur when the input device 100 does not correct the XY coordinates will be described. The barycentric coordinates are the XY coordinates of the fingertip FT calculated by the coordinate calculation unit 130 as the position of the barycentric center.

[0032] In FIG. 2, the horizontal axis represents the X direction, and the vertical axis represents the capacitance. Since deviations between the barycentric coordinates and the position of the fingertip FT can occur in both the X and Y directions, for simplicity's sake, we will explain the deviation between the X coordinate of the barycentric coordinates and the position of the fingertip FT in the X direction. Also, we will explain here assuming that eight electrodes 112 are arranged in the X direction, and eight capacitance values can be obtained. The positions of the eight electrodes 112 are positions 0 to 7 in the X direction.

[0033] Figure 2 shows the capacitance distribution in the X direction, the position of the fingertip FT, and the center of gravity coordinate (X coordinate) when touch input or hover input is performed using three patterns (1), (2), and (3). The position of the fingertip FT is indicated by a hollow arrow, and the center of gravity coordinate is indicated by a solid arrow.

[0034] Pattern (1) shows the capacitance distribution when the fingertip FT touches the operation surface 101A near the center in the X direction. That is, this is the case when a touch input is performed near the center in the X direction. In this case, the capacitance distribution changes relatively sharply with the position of the fingertip FT as the approximate center, and a relatively symmetrical distribution is obtained in the ±X direction with the position of the fingertip FT as the approximate center. This is because the fingertip FT is touching the operation surface 101A, so the capacitance is large at the position of the fingertip FT, and because the fingertip FT is touching near the center of the operation surface 101A, the capacitance is largest near the center in the X direction, and the capacitance decreases as the distance from the position of the fingertip FT increases.

[0035] When a capacitance distribution like pattern (1) is obtained, for example, the centroid coordinates are calculated based on the capacitances of electrodes 112 numbered 0 to 7, so the centroid coordinates are approximately equal to the position of the fingertip FT and the deviation is small. Note that the same results can be obtained by reducing the number of electrodes 112 used to calculate the centroid coordinates and using electrodes 112 numbered 1 to 6 or 2 to 5, etc.

[0036] Pattern (2) shows the capacitance distribution when the fingertip FT touches the operation surface 101A on the -X direction side. That is, when a touch input is performed on the -X direction side. In this case, the capacitance distribution changes relatively sharply with the position of the fingertip FT approximately at the center, but because the position of the fingertip FT is on the -X direction side, the capacitance distribution is asymmetric in the ±X direction with respect to the position of the fingertip FT. Because the fingertip FT is touching the operation surface 101A, the capacitance increases at the position of the fingertip FT, but this is because the position of the fingertip FT is offset to the -X direction side from the center in the X direction.

[0037] When a capacitance distribution like pattern (2) is obtained, for example, the centroid coordinates are calculated based on the capacitances of electrodes 112 numbered 0 to 7, and therefore the centroid coordinates are shifted toward the center in the X direction (+X direction side) from the position of the fingertip FT. When comparing the capacitances of the two electrodes 112 on either side of electrode 112 numbered 1 located directly below the position of the fingertip FT, the capacitance of electrode 112 numbered 2 located toward the center in the X direction is greater than the capacitance of electrode 112 numbered 0 located on the outer side in the X direction (-X direction side), and this is because the difference is large and there are more electrodes 112 on the +X direction side than electrode 112 numbered 1 located directly below the position of the fingertip FT.

[0038] Pattern (3) shows the capacitance distribution when the fingertip FT is close to the operation surface 101A on the -X direction side. That is, when a hover input is performed on the -X direction side. The X direction position of the fingertip FT performing the hover input in pattern (3) is equal to the X direction position of the fingertip FT performing the touch input in pattern (2).

[0039] In the case of hover input, the Z position of fingertip FT is farther from the operation surface 101A than in the case of touch input, and the distance from the operation surface 101A is longer, so the capacitance of electrode 112 directly below fingertip FT is smaller than in the case of touch input. Therefore, the distribution of capacitance approximately centered on the position of fingertip FT becomes gentler, and because the position of fingertip FT is on the -X direction side, the distribution of capacitance becomes asymmetric in the ±X directions with respect to the position of fingertip FT.

[0040] When a capacitance distribution like that of pattern (3) is obtained, for example, the centroid coordinates are calculated based on the capacitances of electrodes 112 numbered 0 to 7, and therefore the centroid coordinates are shifted toward the center in the X direction (+X direction) from the position of the fingertip FT. Furthermore, because the capacitance distribution is gentle, the centroid coordinates are shifted farther toward the center than in the case of pattern (2).

[0041] Since hover input is an input operation performed without touching the operation surface 101A, as the Z-direction distance between the operation surface 101A and the fingertip FT increases, the capacitance of the electrodes 112 from electrode 0 to electrode 7 decreases, and the distribution of the capacitance becomes gentler. As the distribution of the capacitance becomes gentler, the capacitance of the electrodes 112 from electrode 0 to electrode 7 tends to become equal, so the centroid coordinates will shift as if pulled toward the center side.

[0042] As can be seen by comparing Pattern (2) and Pattern (3), when an operation is performed on the operation surface 101A with the fingertip FT, depending on the Z-direction distance between the operation surface 101A and the fingertip FT, the way the centroid coordinates shift with respect to the position of the fingertip FT is different, and as the Z-direction distance between the operation surface 101A and the fingertip FT increases, the centroid coordinates shift toward the center side.

[0043] Also, as can be seen by comparing Pattern (1) and Pattern (2), when performing touch input, depending on the X-direction position of the fingertip FT, the way the centroid coordinates shift with respect to the position of the fingertip FT is different, and as the position of the fingertip FT moves toward the end in the X direction, the shift between the position of the fingertip FT and the centroid coordinates becomes larger. Next, the shift of the XY coordinates calculated as the centroid coordinates will be described using FIG. 3.

[0044] <Shift of XY coordinates> FIG. 3 is a diagram for explaining the shift of the XY coordinates as the centroid coordinates calculated by the coordinate calculation unit 130. FIG. 3(A) shows a state where the sensor unit 110 is divided into four equal parts by the X-axis and the Y-axis. Here, the origin O of the XYZ coordinates is a point directly above the center of the sensor unit 110 on the operation surface 101A. Therefore, the origin O is shown at the center of the sensor unit 110 in FIG. 3(A). The Z coordinate of the operation surface 101A is Z = 0 mm. Therefore, the Z-direction position of the fingertip FT when performing touch input is Z = 0 mm.

[0045] Fig. 3(B) shows the distribution of barycentric coordinates obtained when a touch input is performed at a position Z=0 mm while shifting the position of the fingertip FT at equal intervals in the X and Y directions in the entire region within the second quadrant of the sensor unit 110 shown in Fig. 3(A). In Fig. 3(B), each dot indicates an XY coordinate as the barycentric coordinate calculated by the coordinate calculation unit 130. That is, Fig. 3(B) shows the distribution of barycentric coordinates obtained when a touch input is performed at a position Z=0 mm while shifting the position of the fingertip FT at equal intervals in the X direction from the end on the -X direction side to the end on the +X direction side, and in the Y direction from the end on the -Y direction side to the end on the +Y direction side, in the second quadrant of the sensor unit 110 shown in Fig. 3(A).

[0046] 3(C) shows the distribution of center of gravity coordinates obtained when a hover input is performed at a position Z=20 mm while shifting the position of the fingertip FT at equal intervals in the X and Y directions in the entire region within the second quadrant of the sensor unit 110 shown in FIG. 3(A). In FIG. 3(C), each dot indicates an XY coordinate as the center of gravity coordinate calculated by the coordinate calculation unit 130. That is, FIG. 3(C) shows the distribution of center of gravity coordinates obtained when a hover input is performed at a position Z=20 mm while shifting the position of the fingertip FT at equal intervals in the X direction from the end on the −X direction side to the end on the +X direction side, and in the Y direction from the end on the −Y direction side to the end on the +Y direction side, in the second quadrant of the sensor unit 110 shown in FIG. 3(A).

[0047] As shown in Figure 3(B), the center of gravity coordinates obtained when touch input is performed at the position Z = 0 mm are distributed over the entire area within the second quadrant, and therefore are considered to correctly represent the position of the fingertip FT.

[0048] In contrast, as shown in Figure 3(C), the center of gravity coordinates obtained when hover input is performed at the position of Z = 20 mm are generally shifted toward the origin O within the second quadrant, indicating that distortion has occurred in the center of gravity coordinates. Only the center of gravity coordinates in the second quadrant are shown here, but it is thought that the center of gravity coordinates will similarly shift toward the origin O in the first, third, and fourth quadrants.

[0049] 3(C), the centroid coordinates obtained when a hover input is performed at a position of Z=20 mm have dots spaced relatively evenly close to the origin O, but the further away from the origin O, the shorter the spacing between the dots and the denser they become. This indicates that the further away from the origin O, the greater the deviation of the centroid coordinates from the position of the fingertip FT. The origin O is the center of the sensor unit 110 and the operation surface 101A in a planar view.

[0050] 3(B) and 3(C) as described above, and the difference with the patterns (2) and (3) explained using FIG. 2, it was found that the XY coordinates as the center of gravity coordinates calculated by the coordinate calculation unit 130 are shifted toward the origin O depending on the Z coordinate of the fingertip FT. Furthermore, it was found that when performing a hover input, the capacitance distribution such as pattern (3) becomes gentler (closer to flat) as the distance in the Z direction between the operation surface 101A and the fingertip FT increases, and the center of gravity coordinates are shifted toward the center as the distance in the Z direction between the operation surface 101A and the fingertip FT increases.

[0051] Therefore, the input device 100 corrects the X and Y coordinates as the center of gravity coordinates calculated by the coordinate calculation unit 130 to shift them toward the end of the operation surface 101A according to the Z coordinate of the fingertip FT, thereby bringing the corrected X and Y coordinates closer to the position of the fingertip FT. Furthermore, the input device 100 increases the degree of correction for correcting the center of gravity coordinates as the value of the Z coordinate of the fingertip FT increases (as the distance in the Z direction between the operation surface 101A and the fingertip FT increases), thereby bringing the corrected X and Y coordinates closer to the position of the fingertip FT according to the Z coordinate of the fingertip FT.

[0052] At this time, the input device 100 increases the degree of correction for correcting the center of gravity coordinates the farther away from the central coordinates of the operation surface 101A, thereby bringing the corrected XY coordinates closer to the position of the fingertip FT according to the Z coordinate of the fingertip FT.

[0053] Specifically, the correction degree setting unit 141 and the correction calculation unit 142 of the coordinate correction unit 140 perform the following processing.

[0054] The correction degree setting unit 141 sets a correction degree C for correcting the XY coordinates calculated by the coordinate calculation unit 130, based on the Z coordinate calculated by the coordinate calculation unit 130. The correction degree setting unit 141 sets a larger correction degree C as the calculated Z coordinate increases, and sets a smaller correction degree C as the calculated Z coordinate decreases.

[0055] Furthermore, the correction degree setting unit 141 sets the correction degree C to a larger value as the XY coordinates calculated by the coordinate calculation unit 130 are farther from the central coordinates of the operation surface 101A, and sets the correction degree C to a smaller value as the XY coordinates calculated by the coordinate calculation unit 130 are closer to the central coordinates of the operation surface 101A.

[0056] The correction calculation unit 142 corrects the XY coordinate (X, Y) of the XYZ coordinate (X, Y, Z) calculated by the coordinate calculation unit 130 according to, for example, the following equations (1) and (2), thereby obtaining the corrected XY coordinate (Xc, Yc). O An appropriate constant is to be inserted in . When calculating the corrected XY coordinate (Xc, Yc), the Z coordinate (Z) of the XYZ coordinate (X, Y, Z) calculated by the coordinate calculation unit 130 is used. Note that the center coordinate of the operation surface 101A is (X O ,Y O ) Here, the center of the operation surface 101A coincides with the origin O, so the center coordinates (X O ,Y O )=(0,0). Xc=X O +(XX O )×C O ×Z (1) Yc=Y O +(YY O )×C O ×Z (2)

[0057] In this case, the correction degree C is the difference between the coordinates after correction and the coordinates before correction, and can be expressed as in the following equation (3).

[0058]

number

[0059] <Flowchart> Fig. 4 is a diagram showing a flowchart illustrating the processing executed by the coordinate calculation unit 130 and the coordinate correction unit 140. The flowchart shown in Fig. 4 is processing that is realized by the microcomputer 150 executing a program stored in the memory.

[0060] When the process starts, the coordinate calculation unit 130 determines whether or not detection data has been obtained from the detection unit 120 (step S1). If the coordinate calculation unit 130 determines that detection data has not been obtained (S1: NO), it repeats the process of step S1.

[0061] When the coordinate calculation unit 130 determines that it has received detection data from the detection unit 120 (S1: YES), it calculates spatial coordinates based on the capacitance represented by the detection data (step S2). The coordinate calculation unit 130 calculates the XY coordinates of the spatial coordinates as an example of the centroid coordinates, and calculates the distance corresponding to the capacitance represented by the detection data with the largest change in capacitance as the Z coordinate of the fingertip FT.

[0062] Next, the correction degree setting unit 141 sets the correction degree C for correcting the XY coordinates based on the Z coordinate calculated by the coordinate calculation unit 130 (step S3).

[0063] Next, the correction calculation unit 142 calculates the corrected XY coordinates (Xc, Yc) after correction by correcting the XY coordinates (X, Y) calculated by the coordinate calculation unit 130 according to equations (1) and (2) (step S4). This completes the series of processes. When the process of step S4 is completed, the flow returns to the start.

[0064] The correction calculation unit 142 may calculate the corrected X coordinate Xc or Y coordinate Yc after correction by correcting either one of the X and Y coordinates (X, Y) calculated by the coordinate calculation unit 130 according to equation (1) or equation (2). For example, this may be done in cases where only the X coordinate or only the Y coordinate needs to be corrected depending on the characteristics of the sensor unit 110.

[0065] <Effects> As described above, the X coordinate or Y coordinate in the spatial coordinate system is corrected based on the Z coordinate in the spatial coordinate system calculated by the coordinate calculation unit 130. Therefore, it is possible to correct the distortion of the spatial coordinate system calculated by the coordinate calculation unit 130 and calculate the corrected X coordinate or Y coordinate representing the position of the fingertip FT.

[0066] Therefore, it is possible to provide a position detection device 100A, an input device 100, and a position detection method that can correct the X and Y coordinates of the fingertip FT on the operation surface 101A according to the degree of contact or proximity. Furthermore, since the X or Y coordinate is corrected based on the Z coordinate calculated by the coordinate calculation unit 130, it is possible to prevent the X or Y coordinate after correction from changing suddenly, and the X or Y coordinate can be corrected so that it changes smoothly and gradually according to the Z coordinate.

[0067] The degree of contact or proximity is represented by the capacitance of the fingertip FT at the detection position, and the coordinate calculation unit 130 calculates a coordinate value on the Z axis based on multiple pieces of detection data represented by capacitance. The capacitance between the sensor unit 110 and the fingertip FT changes depending on the distance in the Z direction between the operation surface 101A and the fingertip FT, so the Z coordinate at the time of contact or proximity can be easily and reliably determined.

[0068] Furthermore, the coordinate correcting unit 140 increases the correction degree C for correcting the X coordinate or the Y coordinate as the Z coordinate calculated by the coordinate calculating unit 130 increases. Since the distortion of the spatial coordinate calculated by the coordinate calculating unit 130 increases as the distance in the Z direction between the operation surface 101A and the fingertip FT increases, stronger correction can be performed when the distortion is large, and distortion of the X and Y coordinates of the spatial coordinates calculated by the coordinate calculating unit 130 can be corrected according to the Z coordinate of the fingertip FT.

[0069] Furthermore, the coordinate calculation unit 130 calculates the X coordinate and the Y coordinate by performing a center of gravity calculation on the multiple detection data output from the detection unit 120, so that the influence of noise, etc. can be suppressed and the center of gravity coordinates on the XY plane of the fingertip FT can be calculated as XY coordinates.

[0070] Furthermore, the coordinate correcting unit 140 corrects the X coordinate or the Y coordinate so as to shift it toward the edge of the operation surface 101A. Since the X and Y coordinates as the center of gravity coordinates calculated by the coordinate calculating unit 130 are distorted toward the center, the distortion of the X and Y coordinates calculated by the coordinate calculating unit 130 can be corrected by correcting it in a direction shifting it toward the edge of the operation surface 101A.

[0071] Furthermore, coordinate corrector 140 increases the correction degree C by which the X coordinate is corrected as the X coordinate is farther away from the central coordinate corresponding to the center of operation surface 101A. Since the X coordinate as the center of gravity coordinate calculated by coordinate calculation unit 130 is distorted more toward the center at the edge of operation surface 101A, by increasing correction degree C as the X coordinate is farther away from the central coordinate, it is possible to more appropriately correct the distortion of the X coordinate calculated by coordinate calculation unit 130 according to the distance from the central coordinate.

[0072] Furthermore, the coordinate correcting unit 140 increases the correction degree C by which the Y-axis coordinate value is corrected as the Y-axis coordinate value is farther away from the central coordinate corresponding to the center of the operation surface 101A. The Y-coordinate as the center of gravity coordinate calculated by the coordinate calculating unit 130 is distorted more toward the center at the edge of the operation surface 101A, so by increasing the correction degree C as the distance from the central coordinate increases, the distortion of the Y-coordinate calculated by the coordinate calculating unit 130 can be more appropriately corrected according to the distance from the central coordinate.

[0073] <Modification> In the above, a form has been described in which the XY coordinates calculated as the center of gravity coordinates are corrected using the correction degree C set based on the Z coordinate in the spatial coordinates calculated by the coordinate calculation unit 130.

[0074] However, the present invention is not limited to correcting the X and Y coordinates using the correction degree C. For example, a threshold value may be set for the Z coordinate among the spatial coordinates calculated by the coordinate calculation unit 130, and correction may be performed using equations (1) and (2) when the Z coordinate is equal to or greater than the threshold. For example, when a touch input is performed (when Z=0 mm) or when a hover input is performed and the position of the fingertip FT is extremely close to the operation surface 101A (for example, the Z coordinate is less than 5 mm), if the distortion of the X and Y coordinates as the center of gravity coordinates calculated by the coordinate calculation unit 130 is small enough to not cause a problem, correction may be performed using equations (1) and (2) when the Z coordinate is equal to or greater than the threshold. In this case, when the Z coordinate is less than the threshold, the X and Y coordinates as the center of gravity coordinates calculated by the coordinate calculation unit 130 may be output as is to the operation target device 10.

[0075] Even when a threshold value is set for the Z coordinate in this way, it is possible to provide a position detection device 100A, an input device 100, and a position detection method that can correct the XY coordinates of the fingertip FT on the operation surface 101A depending on the degree of contact or proximity.

[0076] In the above, the coordinate calculation unit 130 calculates the Z coordinate, and the coordinate correction unit 140 corrects the X and Y coordinates by setting the correction degree C according to the Z coordinate. However, because the Z coordinate is a value inversely proportional to the capacitance of the detection data, the X and Y coordinates may be corrected according to the capacitance represented by the detection data without calculating the Z coordinate. In this case, the larger the capacitance, the smaller the correction degree for correcting the X or Y coordinate should be. Because the Z coordinate is a value inversely proportional to the capacitance of the detection data, the X and Y coordinates can be corrected based on the Z coordinate without calculating the Z coordinate.

[0077] The above describes exemplary embodiments of the position detection device, input device, and position detection method of the present disclosure. However, the present invention is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0078] This international application claims priority based on Japanese Patent Application No. 2021-192686, filed on November 29, 2021, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0079] 100 Input Device 100A Position Detector 101 Cover 101A Operation surface 110 Sensor unit 110 Sensor unit 111 Substrate 112 Electrode 120 Detector 130 Coordinate calculation unit 140 Coordinate correction unit 141 Correction degree setting unit 142 Correction calculation section 150 Microcomputer

Claims

1. a detection unit that detects the degree of contact or proximity of an object to the operation surface at a plurality of detection positions on the operation surface and outputs a plurality of detection data representing the degree at the plurality of detection positions; a coordinate calculation unit that calculates spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis included in a plane parallel to the operation surface, based on a plurality of detection data detected by the detection unit; a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the coordinate value of the third axis in the spatial coordinate system calculated by the coordinate calculation unit; Including, The coordinate correction unit corrects the coordinate value of the first axis or the coordinate value of the second axis so as to shift the coordinate value toward an end of the operation surface.

2. A detection unit that detects the degree of contact or proximity of an object to an operation surface at a plurality of detection positions on the operation surface and outputs a plurality of detection data representing the degree at the plurality of detection positions; a coordinate calculation unit that calculates spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis included in a plane parallel to the operation surface, based on a plurality of detection data detected by the detection unit; a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the coordinate value of the third axis in the spatial coordinate system calculated by the coordinate calculation unit; Including, The coordinate correction unit increases the degree of correction for correcting the coordinate value of the first axis as the coordinate value of the first axis is farther from a central coordinate corresponding to the center of the operation surface.

3. A detection unit that detects the degree of contact or proximity of an object to the operation surface at a plurality of detection positions on the operation surface and outputs a plurality of detection data representing the degree at the plurality of detection positions; a coordinate calculation unit that calculates spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis included in a plane parallel to the operation surface, based on a plurality of detection data detected by the detection unit; a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the coordinate value of the third axis in the spatial coordinate system calculated by the coordinate calculation unit; Including, The coordinate correction unit increases the degree of correction for correcting the coordinate value of the second axis as the coordinate value of the second axis is farther from a central coordinate corresponding to the center of the operation surface.

4. the degree is represented by the capacitance of the object at the detection position, The position detection device according to claim 1 , wherein the coordinate calculation unit calculates the coordinate value of the third axis based on the plurality of detection data represented by the capacitances.

5. 4. The position detection device according to claim 1, wherein the coordinate correction unit increases the degree of correction for correcting the coordinate value of the first axis or the coordinate value of the second axis as the coordinate value of the third axis calculated by the coordinate calculation unit increases.

6. 4. The position detection device according to claim 1, wherein the coordinate calculation unit calculates the coordinate values of the first axis and the coordinate values of the second axis by performing a center of gravity calculation on the plurality of detection data output from the detection unit.

7. The position detection device according to claim 1 , wherein the first axis, the second axis, and the third axis are orthogonal to one another.

8. A sensor unit disposed on the back side of an operation surface, which outputs a physical quantity representing the degree of contact or proximity of an object to the operation surface at a plurality of detection positions on the operation surface; a detection unit that detects the degree and outputs a plurality of detection data representing the degree at the plurality of detection positions; a coordinate calculation unit that calculates spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis included in a plane parallel to the operation surface, based on a plurality of detection data detected by the detection unit; a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the coordinate value of the third axis in the spatial coordinate system calculated by the coordinate calculation unit; Including, The coordinate correction unit corrects the coordinate value of the first axis or the coordinate value of the second axis so as to shift the coordinate value toward an end of the operation surface.

9. A sensor unit disposed on the back side of an operation surface, which outputs a physical quantity representing the degree of contact or proximity of an object to the operation surface at a plurality of detection positions on the operation surface; a detection unit that detects the degree and outputs a plurality of detection data representing the degree at the plurality of detection positions; a coordinate calculation unit that calculates spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis included in a plane parallel to the operation surface, based on a plurality of detection data detected by the detection unit; a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the coordinate value of the third axis in the spatial coordinate system calculated by the coordinate calculation unit; Including, The coordinate correction unit increases the degree of correction for correcting the coordinate value of the first axis as the coordinate value of the first axis is farther from a central coordinate corresponding to a center of the operation surface.

10. A sensor unit disposed on the back side of an operation surface, which outputs a physical quantity representing the degree of contact or proximity of an object to the operation surface at a plurality of detection positions on the operation surface; a detection unit that detects the degree and outputs a plurality of detection data representing the degree at the plurality of detection positions; a coordinate calculation unit that calculates spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis included in a plane parallel to the operation surface, based on a plurality of detection data detected by the detection unit; a coordinate correction unit that corrects the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the coordinate value of the third axis in the spatial coordinate system calculated by the coordinate calculation unit; Including, The coordinate correction unit increases the degree of correction for correcting the coordinate value of the second axis as the coordinate value of the second axis is farther away from a central coordinate corresponding to a center of the operation surface.

11. Detecting the degree of contact or proximity of an object to an operation surface at a plurality of detection positions on the operation surface, and outputting a plurality of detection data representing the degree at the plurality of detection positions; calculating, based on the detected plurality of pieces of detection data, spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis, all of which are included in a plane parallel to the operation surface; correcting the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the calculated coordinate value of the third axis in the spatial coordinate system; a position detection method for correcting the coordinate value of the first axis or the coordinate value of the second axis so as to shift it toward an end of the operation surface;

12. Detecting the degree of contact or proximity of an object to an operation surface at a plurality of detection positions on the operation surface, and outputting a plurality of detection data representing the degree at the plurality of detection positions; calculating, based on the detected plurality of pieces of detection data, spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis, all of which are included in a plane parallel to the operation surface; correcting the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the calculated coordinate value of the third axis in the spatial coordinate system; The position detection method, wherein the degree of correction for correcting the coordinate value of the first axis increases as the coordinate value of the first axis becomes farther from a central coordinate corresponding to a center of the operation surface.

13. Detecting the degree of contact or proximity of an object to an operation surface at a plurality of detection positions on the operation surface, and outputting a plurality of detection data representing the degree at the plurality of detection positions; calculating, based on the detected plurality of pieces of detection data, spatial coordinates of the object in a spatial coordinate system having a first axis, a second axis, and a third axis, all of which are included in a plane parallel to the operation surface; correcting the coordinate value of the first axis or the coordinate value of the second axis in the spatial coordinate system based on the calculated coordinate value of the third axis in the spatial coordinate system; The position detection method, wherein the degree of correction for correcting the coordinate value of the second axis increases as the coordinate value of the second axis becomes farther from a central coordinate corresponding to the center of the operation surface.

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