JP2018200601A - Inclination derivation device and inclination derivation method - Google Patents

Abstract

To provide an inclination derivation device and an inclination derivation method that can accurately derive the inclination of an indicator.SOLUTION: An inclination derivation device derives the inclination of a pen-shaped indicator, and the indicator comprises: a first electrode provided at one end in the axial direction; a second electrode provided around the axis; a planar sensor detecting the positions of the first and second electrodes; and a control unit 10. The control unit 10 includes: a first look-up table 15A in which the correspondence between a first input value calculated on the basis of the respective positions of the first and second electrodes and a first correction value θthat is a correction value of the inclination of the axis, when the indicator is inclined from a direction orthogonal to the sensor toward a first direction on the sensor is registered; a second look-up table 15B when the indicator is inclined toward a second direction different from the first direction; an input calculation unit 14 that calculates input values and inputs the input values to the look-up tables; a rotation angle calculation unit 16 that derives the rotation angle φ of the axis; and an inclination direction inclination correction value calculation unit 17 that calculates a correction value θof inclination in the inclination direction from the rotation angle φ and correction value.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an inclination derivation device and an inclination derivation method.

In recent years, a position detection device such as a touch panel in which a sensor such as a touch pad for detecting a specified position on a display device is combined with a display device such as a liquid crystal panel has been widely used.
For example, when an accurate input to the position detection device is required, the input to the position detection device may be performed using a pointed bar-like stylus pen. Currently, various types of stylus pens are used, and among them, an active electrostatic coupling type stylus pen is becoming widespread.

As shown in FIG. 11, the active electrostatic coupling type stylus pen 101 includes a plurality of, for example, two first electrodes 101a and second electrodes 101b, and a drive circuit (not shown) for driving them. The first electrode 101a is provided at one end of the stylus pen 101 in the axis C direction, and the second electrode 101b is provided around the axis C, for example, in a ring shape so as to surround the axis C. The position indicated by the stylus pen 101 is detected when the sensor 100a on the position detection device 100 receives the signal transmitted by each of the electrodes 101a and 101b driven by the drive circuit by electrostatic coupling.
Patent Document 1 discloses a support, a position detection device, and a position detection method as described above.

  Depending on the application program operating on the position detection device using the stylus pen, that is, the indicator and the position detection device as described above, the inclination of the indicator with respect to the position detection device may be required as an input. . In such a case, generally, the detection coordinate of the first electrode 101a on the XY plane is A, the detection coordinate of the second electrode 101b is B, and the first electrode 101a and the second electrode in the direction of the axis C of the indicator 101 When the distance of the electrode 101b is L, the inclination of the axis C is derived by calculation based on these values.

JP2011-164801A

When the indicator 101 as shown in FIG. 11 is used, the first electrode 101a is in close contact with the position detection device 100, but the second electrode 101b is separated from the position detection device 100 by a height H. Is positioned. For this reason, compared with the 1st electrode 101a, the detection value by the sensor 100a becomes small for the 2nd electrode 101b.
Further, as described above, the second electrode 101b is formed around the axis C, for example, in a ring shape so as to surround the axis C, and has a volume larger than that of the first electrode 101a. The range detected as the electrode 101b is large.
As described above, the sensor 100a detects a region where small detection values are widely distributed as the position of the second electrode 101b. For this reason, it is not easy for the position detection device 100 to accurately specify the detection coordinate B of the second electrode 101b that is the basis of the above-described calculation of the inclination.

  Since the second electrode 101b is provided in a ring shape around the axis C, for example, so as to surround the axis C, the shape of the region detected by the position detection device 100 as the position of the second electrode 101b is indicated by the indicator 101. It changes with the inclination of the and does not become a constant shape. For this reason, for example, it is not easy to specify the coordinate B based on the shape of the region corresponding to the second electrode 101b.

  The second electrode 101b is provided at a position spaced from the axis C by a certain distance. For this reason, the value of the distance L between the electrodes 101a and 101b to be considered at the time of calculation in accordance with the inclination of the indicator 101 needs to be handled as an effective value that changes strictly.

  Furthermore, as described above, the detection value of the second electrode 101b by the sensor 100a is a small value. For this reason, when some kind of noise intervenes, the noise greatly affects, and the coordinate B is more difficult to specify.

  Since the above factors are synergistic and it is difficult to accurately specify the coordinate B, the value of the specified coordinate B tends to include a lot of errors. As a result, the accuracy of the inclination derived purely by the theoretical formula based on the value of the coordinate B specified as described above is not high.

In general, the sensor 100a is formed by a plurality of conductors extending in two orthogonal directions. Each of these conductors has a predetermined width, and the conductors overlap each other at a portion where conductors extending in different directions intersect to form one unit 102.
The length 102x in the X direction and the length 102y in the Y direction of this unit 102 may differ depending on the number of conductors in both the XY directions. When the position detection device 100 is a display device, the lengths 102x and 102y of one unit 102 can also depend on the resolution in both the XY directions. Along with this, there may be a difference in the sensitivity of one unit 102 in both XY directions.
In such a case, even if the indicator 101 is tilted by the same angle in each of the X direction and the Y direction, different values can be detected. That is, if the length of one unit 102 of the sensor is different in the X direction and the Y direction, the accuracy of the derived tilt can be further reduced.

  The problem to be solved by the present invention is to provide an inclination deriving device and an inclination deriving method capable of deriving the inclination of an indicator with high accuracy.

An inclination deriving device according to the present invention is an inclination deriving device for deriving an inclination of a pen-shaped indicator, wherein the indicator is provided at a first electrode provided at one end in an axial direction and around the axis. A planar sensor for detecting the position of the first electrode, the position of the second electrode, and a control unit, and the control unit orthogonally crosses the indicator with the sensor. A first input value corresponding to a value calculated based on the position of each of the first and second electrodes when tilted from the orthogonal direction toward the first direction on the sensor, and the inclination of the axis; A first look-up table in which a correspondence relationship with a first correction value that is a correction value is registered, and when the indicator is tilted in a second direction different from the first direction on the sensor, A second input value corresponding to a value calculated based on the position of each of the first and second electrodes; The input value is calculated based on the second lookup table in which the correspondence relationship with the second correction value, which is the correction value of the tilt of the axis, is registered, and the position of each of the first and second electrodes. The first and second input values to be input to the first and second lookup tables, and the first and second electrodes based on the positions of the first and second electrodes from the first direction. A rotation angle calculation unit for deriving a rotation angle of the shaft in two directions, and an inclination of the shaft in a direction in which the shaft is inclined from the orthogonal direction from the rotation angle and the first and second correction values. An inclination direction inclination correction value calculation unit for calculating an inclination direction inclination correction value.
According to the above configuration, due to factors such as the weak detection value resulting from the second electrode being away from the sensor and the wide detection range resulting from the shape of the second electrode, the first and second electrodes Even if the input value calculated based on each position contains a lot of errors, the corrected values corresponding to this error are stored in the first and second look-up tables, and the inclination in the tilt direction is stored. The correction value calculation unit calculates a correction value for the inclination in the tilt direction from the correction value, that is, the first and second correction values output from the first and second lookup tables. For this reason, it is possible to increase the accuracy of the calculated inclination in the inclination direction and to accurately derive the inclination of the indicator.
The first and second look-up tables include first and second correction values that are correction values for the tilt of the axis when the indicator is tilted in different first and second directions. Stored. Further, the tilt direction tilt correction value calculation unit calculates the tilt direction tilt based on the first and second correction values and the rotation angle of the shaft from the first direction to the second direction calculated by the rotation angle calculation unit. Calculate the correction value. That is, the direction in which the axis is inclined between the first direction and the second direction is calculated, and a correction value when the axis is inclined in the first direction and a correction value when the axis is inclined in the second direction, for example, are proposed. The correction value of the inclination in the inclination direction can be calculated by a minute process or the like. Thereby, even if the length and sensitivity of one unit of the sensor are different in the first direction and the second direction, the accuracy of the calculated tilt direction tilt can be improved, and the tilt of the indicator can be derived accurately. .

In one aspect of the present invention, the inclination direction inclination correction value calculation unit performs the inclination direction inclination by a prorated process between the first correction value and the second correction value according to the rotation angle value. The correction value is calculated.
According to the configuration as described above, both the first correction value when the axis is tilted in the first direction and the second correction value when the axis is tilted in the second direction, depending on the value of the rotation angle. Proper processing is performed. For this reason, each of the first correction value and the second correction value can be appropriately reflected when calculating the correction value of the inclination in the tilt direction. Thereby, even if the length and sensitivity of one unit of the sensor are different in the first direction and the second direction, the accuracy of the calculated tilt direction tilt can be improved, and the tilt of the indicator can be derived accurately. .

In another aspect of the present invention, the inclination direction inclination correction value calculation unit converts the rotation angle into an angle between the first direction and the second direction, calculates a conversion value, and converts the conversion value. The prorated process is performed based on the value.
According to the configuration as described above, the rotation angle is converted into an angle between the first direction and the second direction, so that it is possible to appropriately execute the prorated process. Thereby, even if the length and sensitivity of one unit of the sensor are different in the first direction and the second direction, the accuracy of the calculated tilt direction tilt can be improved, and the tilt of the indicator can be derived accurately. .

In another aspect of the present invention, the input calculation unit calculates a sensor distance, which is a distance between the positions of the first and second electrodes on the sensor, and the first electrode in the axial direction and the first electrode. The input value is calculated by dividing by the axial distance which is the distance of the second electrode.
According to the configuration as described above, since a complicated calculation such as a trigonometric function is not required when calculating the input value, the calculation amount and the memory amount can be reduced.

In another aspect of the present invention, based on the correction value of the inclination direction inclination calculated by the inclination direction inclination correction value calculation unit, the inclination of the axis toward the first direction from the orthogonal direction is calculated. The apparatus further includes first and second direction inclination calculation units that derive a certain first direction inclination and a second direction inclination that is an inclination of the axis from the orthogonal direction toward the second direction.
According to the configuration as described above, it is possible to derive the first direction inclination and the second direction inclination with high accuracy.

In another aspect of the present invention, the inclination direction inclination correction value calculation unit outputs the calculated correction value of the inclination direction inclination as the inclination direction inclination.
According to the configuration as described above, it is possible to derive the inclination in the inclination direction with high accuracy.

An inclination deriving method according to the present invention is an inclination deriving method for deriving an inclination instructed by a pen-shaped indicator, and is a first sensor provided at one end in the axial direction of the indicator by a planar sensor. Detecting the position of each of the first electrode and the second electrode provided so as to surround the axis, calculating an input value based on the position of each of the first and second electrodes; and A first input value corresponding to a value calculated based on the position of each of the first and second electrodes when tilted from an orthogonal direction orthogonal to the sensor toward the first direction on the sensor; The input value is input as the first input value to the first lookup table in which the correspondence relationship with the first correction value that is the correction value of the axis inclination is registered, and the indicator is connected to the sensor on the sensor. The first and second directions when tilted in a second direction different from the first direction. A second lookup table in which a correspondence relationship between a second input value corresponding to a value calculated based on the position of each second electrode and a second correction value which is a correction value of the tilt of the axis is registered. The input value is input as the second input value, and the rotation angle of the shaft from the first direction toward the second direction is derived based on the position of each of the first and second electrodes. An inclination that is an inclination of the axis from the orthogonal direction toward the direction in which the axis is inclined from the rotation angle and the first and second correction values output from the first and second look-up tables. Calculate the correction value for the direction tilt.
According to the method as described above, the first and second electrodes may be affected by factors such as a weak detection value caused by the second electrode being away from the sensor and a wide detection range caused by the shape of the second electrode. Even if the input value calculated on the basis of each position contains a large amount of error, the correction value eliminated corresponding to this error is stored in the first and second lookup tables, and this correction value That is, the tilt direction inclination correction value is calculated from the first and second correction values output from the first and second look-up tables. For this reason, it is possible to increase the accuracy of the calculated inclination in the inclination direction and to accurately derive the inclination of the indicator.
The first and second look-up tables include first and second correction values that are correction values for the tilt of the axis when the indicator is tilted in different first and second directions. Stored. Further, the correction value of the inclination in the tilt direction is calculated based on the first and second correction values and the rotation angle of the axis from the first direction to the second direction calculated by the rotation angle calculation unit. That is, it calculates which direction the axis is tilted between the first direction and the second direction, and the correction value when tilted in the first direction and the correction value when tilted in the second direction, For example, the correction value of the tilt in the tilt direction can be calculated by prorated processing. Thereby, even if the length and sensitivity of one unit of the sensor are different in the first direction and the second direction, the accuracy of the calculated tilt direction tilt can be improved, and the tilt of the indicator can be derived accurately. .

In one aspect of the present invention, the correction value of the inclination in the tilt direction is calculated by a proportional process between the first correction value and the second correction value according to the value of the rotation angle.
According to the method as described above, both the first correction value when the axis is tilted in the first direction and the second correction value when the axis is tilted in the second direction depend on the value of the rotation angle. Proper processing is performed. For this reason, each of the first correction value and the second correction value can be appropriately reflected when calculating the correction value of the inclination in the tilt direction. Thereby, even if the length and sensitivity of one unit of the sensor are different in the first direction and the second direction, the accuracy of the calculated tilt direction tilt can be improved, and the tilt of the indicator can be derived accurately. .

In another aspect of the present invention, the rotation angle is converted into an angle between the first direction and the second direction to calculate a conversion value, and the proportional processing is performed based on the conversion value. Is called.
According to the method as described above, since the rotation angle is converted into an angle between the first direction and the second direction, it is possible to appropriately execute the prorated process. Thereby, even if the length and sensitivity of one unit of the sensor are different in the first direction and the second direction, the accuracy of the calculated tilt direction tilt can be improved, and the tilt of the indicator can be derived accurately. .

In another aspect of the present invention, the distance on the sensor, which is the distance between the positions of the first and second electrodes on the sensor, is the distance between the first electrode and the second electrode in the axial direction. The input value is calculated by dividing by a certain axial distance.
According to the method as described above, since a complicated operation such as trigonometric function is not required when calculating the input value, the calculation amount and the memory amount can be reduced.

In another aspect of the present invention, based on the correction value of the inclination in the inclination direction, a first direction inclination that is an inclination of the axis from the orthogonal direction toward the first direction, and from the orthogonal direction A second direction inclination which is an inclination of the axis toward the second direction is derived.
According to the method as described above, it is possible to derive the first direction inclination and the second direction inclination with high accuracy.

In another aspect of the present invention, the calculated correction value of the tilt direction tilt is output as the tilt direction tilt.
According to the method as described above, it is possible to derive the inclination in the inclination direction with high accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the inclination derivation | leading-out apparatus and inclination derivation | leading-out method which can derive | lead-out the inclination of an indicator accurately can be provided.

It is explanatory drawing of the inclination calculation apparatus in embodiment of this invention, and the indicator used with this. It is explanatory drawing of the inclination derivation | leading-out apparatus in the said embodiment. It is a signal processing block diagram of the control part of the inclination derivation device in the embodiment. It is explanatory drawing of the gravity center calculation part of the control part of the inclination derivation device in the embodiment. It is explanatory drawing of the coordinate system by the inclination derivation device in the embodiment. It is an Example of the 1st look-up table of the inclination derivation device in the embodiment. It is an example of the 2nd look-up table of the inclination derivation device in the embodiment. It is explanatory drawing of the experimental result in the said embodiment. It is a signal processing block diagram of the control part in the modification of the said embodiment. It is a partial signal processing block diagram of a control part in other modifications of the embodiment. It is explanatory drawing of an inclination derivation | leading-out apparatus and an indicator.

The tilt deriving device in the present embodiment is a tilt deriving device for deriving the tilt of the pen-shaped indicator, and the indicator is provided around the first electrode provided at one end in the axial direction and the axis. A second electrode; a planar sensor for detecting the position of the first electrode; a position of the second electrode; and a controller, the controller on the sensor from an orthogonal direction perpendicular to the sensor. A first input value corresponding to a value calculated on the basis of the position of each of the first and second electrodes when tilted in the first direction, and a first correction value which is a correction value of the axis inclination; Based on the first look-up table in which the correspondence relationship is registered and the positions of the first and second electrodes when the indicator is tilted in a second direction different from the first direction on the sensor. Correspondence between the second input value corresponding to the calculated value and the second correction value which is the correction value of the axis inclination is registered. The input value is calculated based on the second lookup table and the positions of the first and second electrodes, and is input to the first and second lookup tables as the first and second input values. A rotation angle calculation unit for deriving a rotation angle of the axis from the first direction to the second direction based on the position of each of the first and second electrodes, the rotation angle, and the first and second correction values To an inclination direction inclination correction value calculation unit for calculating an inclination direction inclination correction value that is an inclination of the axis from the orthogonal direction to the direction in which the axis is inclined.
An inclination derivation method according to the present invention is an inclination derivation method for deriving an inclination instructed by a pen-shaped indicator, and is a first sensor provided at one end in the axial direction of the indicator by a planar sensor. The position of each of the electrode and the second electrode provided so as to surround the axis is detected, the input value is calculated based on the position of each of the first and second electrodes, and the indicator is orthogonal to the sensor. A first input value corresponding to a value calculated based on the position of each of the first and second electrodes when tilted toward the first direction on the sensor, and a correction value for the tilt of the axis. When the input value is input as the first input value to the first look-up table in which the correspondence with the one correction value is registered, and the indicator is tilted in the second direction different from the first direction on the sensor A second input value corresponding to a value calculated based on the position of each of the first and second electrodes; The input value is input as the second input value to the second lookup table in which the correspondence relationship with the second correction value that is the correction value of the tilt is registered, and based on the position of each of the first and second electrodes The rotation angle of the shaft from the first direction to the second direction is derived, and the tilt of the shaft from the orthogonal direction is calculated from the rotation angle and the first and second correction values output from the first and second lookup tables. The correction value for the inclination in the inclination direction, which is the inclination of the axis in the direction of the inclination, is calculated.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram of an inclination deriving device 1 and an indicator 101 used therewith in the embodiment of the present invention. FIG. 2 is an explanatory diagram of the inclination deriving device 1.
The indicator 101 has a pen shape, a first electrode 101a provided at one end in the direction of the axis C, a second electrode 101b provided around the axis C, and a drive circuit (not shown) for driving them. It has.
In the present embodiment, the second electrode 101b is provided in a ring shape so as to surround the axis C.
The first and second electrodes 101a and 101b transmit signals to the tilt deriving device 1 by electrostatic coupling with a sensor 2 of the tilt deriving device 1 described later.

  The inclination deriving device 1 is a tablet information terminal in the present embodiment. The tilt deriving device 1 is provided with a planar capacitive sensor 2 on the surface of a display device such as a liquid crystal panel, for example, and the sensor 2 is provided over substantially the entire display area of the liquid crystal panel. Thus, the entire display area is a position detectable area 1a by the sensor. The sensor 2 of the inclination deriving device 1 detects the position of the first electrode 101a and the position of the second electrode 101b when the indicator 101 is positioned in the position detectable region 1a, and is instructed by the indicator 101. Detect position.

The sensor 2 includes a plurality of first direction conductors 3 extending in the first direction and a plurality of second direction conductors 4 extending in a second direction orthogonal to the first direction. In the present embodiment, the first direction is the direction X that is the horizontal direction of the paper surface, and the second direction is the direction Y that is the vertical direction of the paper surface.
Each of the first direction conductor 3 and the second direction conductor 4 is formed so that one of the conductors 3 and 4 corresponds to the predetermined number of pixels of the display device in the position detectable region 1a and has a predetermined width. It is provided so as to have a grid shape coarser than the pixels of the display device. In each of the portions where the first direction conductor 3 and the second direction conductor 4 intersect, the conductors 3 and 4 are overlapped to form one unit 2b of the sensor 2 shown in FIG.

The inclination deriving device 1 includes a selection circuit 5. Each end of the first and second direction conductors 3 and 4 is connected to the selection circuit 5. The selection circuit 5 selects each of the first and second direction conductors 3 and 4 in a predetermined order, thereby transmitting the signals from the first and second electrodes 101a and 101b of the indicator 101 to the conductors 3 and 4, respectively. Receive a signal.
The selection circuit 5 transmits signals received from the conductors 3 and 4 to the input data generation unit 6 described below.

The inclination deriving device 1 includes an input data generation unit 6. The input data generation unit 6 classifies the signal received from the selection circuit 5 into a signal received from the first electrode 101a of the indicator 101 and a signal received from the second electrode 101b. It transmits to the control part 10 demonstrated below as 2 electrode data.
This classification is performed, for example, when the sensor 2 and the selection circuit 5 perform signal reception from the first electrode 101a and signal reception from the second electrode 101b in a time division manner.

  The inclination deriving device 1 includes a control unit 10. FIG. 3 is a signal processing block diagram of the control unit 10. The control unit 10 includes a center-of-gravity calculation unit 11, an IIR filter 12, an electrode position difference calculation unit 13, an input calculation unit 14, a look-up table (hereinafter referred to as LUT) 15, a rotation angle calculation unit 16, an inclination direction inclination correction value. A calculation unit 17 and first and second direction inclination calculation units 18 are provided.

The center of gravity calculation unit 11 includes a first center of gravity calculation unit 11A and a second center of gravity calculation unit 11B.
The first center-of-gravity calculation unit 11A receives the first electrode data transmitted from the input data generation unit 6 and calculates the maximum value in each of the direction X and the direction Y. Thus, the first center-of-gravity calculation unit 11A specifies the coordinates on the sensor 2 where the signal transmitted from the first electrode 101a of the indicator 101 is the strongest, that is, the reaction of the first electrode 101a is the strongest.
The first center-of-gravity calculation unit 11A further corresponds to five first and second direction conductors 3 and 4 in each of the vertical and horizontal directions with the coordinates on the sensor 2 having the strongest response of the first electrode 101a as the center. Data in coordinates on a total of 25 sensors 2 are extracted. FIG. 4 explains the 25 data D1 to D25 extracted in this way. In FIG. 4, the data corresponding to the coordinates on the sensor 2 with the strongest response of the first electrode 101a is D13 located at the center.

For the 25 pieces of data, the first center-of-gravity calculation unit 11A integrates the data value D _i and the coordinate values (x _i , y _i ) on the sensor 2 as shown in the following Equation 1. This is divided by the sum of D _i. As a result, the first electrode provisional coordinate values A _t (A _xt , A _yt ), which are coordinate values on the sensor 2 in each of the direction X and the direction Y where the reaction of the first electrode 101a is strongest, are obtained with a granularity below the decimal point. Calculated.

The first center of gravity calculating section 11A transmits a first electrode provisional coordinate values _{A t} to the IIR filter 12.

The second centroid calculating unit 11B receives the second electrode data, and calculates the maximum value in each of the direction X and the direction Y in the same manner as the first centroid calculating unit 11A. Thereby, the second center-of-gravity calculation unit 11B specifies the coordinates on the sensor 2 where the signal transmitted from the second electrode 101b of the indicator 101 is the strongest, that is, the reaction of the second electrode 101b is the strongest.
Similarly to the first centroid calculation unit 11A, the second centroid calculation unit 11B further includes five first and second five in each of the vertical and horizontal directions with the coordinates on the sensor 2 having the strongest response of the second electrode 101b as the center. Data on coordinates on a total of 25 sensors 2 corresponding to the direction conductors 3 and 4 are extracted.
For the 25 pieces of data, the second centroid calculator 11B integrates the data value D _i and the coordinate values (x _i , y _i ) on the sensor 2 in the same manner as the first centroid calculator 11A. , which is divided by the sum of _{D i.} Accordingly, the second electrode provisional coordinate values B _t (B _xt , B _yt ), which are coordinate values on the sensor 2 in each of the direction X and the direction Y where the reaction of the second electrode 101b is the strongest, are calculated.
The second center of gravity calculating section 11B transmits the second electrode provisional coordinate values _{B t} to IIR filter 12.

The IIR filter 12 includes a first IIR filter 12A and a second IIR filter 12B.
The 1IIR filter 12A, from the first center of gravity calculating section 11A receives the first electrode provisional coordinate values _{A t,} reduce the temporal fluctuation by applying the time direction of the IIR filter, a first electrode coordinate value A (A _x , _Ay ) is calculated.
The first IIR filter 12 </ b> A transmits the first electrode coordinate value A to the electrode position difference calculation unit 13.

First 2IIR filter 12B from the second center of gravity calculating section 11B receives the second electrode provisional coordinate values _{B t,} reduce the temporal fluctuation by applying the time direction of the IIR filter, the second electrode coordinate value B (B _x , B _y ) is calculated.
The second IIR filter 12B transmits the second electrode coordinate value B to the electrode position difference calculation unit 13.

The electrode position difference calculation unit 13 receives the first electrode coordinate value A and the second electrode coordinate value B from the first IIR filter 12A and the second IIR filter 12B.
The electrode position difference calculation unit 13 calculates B _x −A _x and B _y −A _y to obtain a difference between the coordinate values A and B, and uses the direction X and the direction Y used in the internal processing of the display device. By converting each internal resolution value, the first direction difference _Sx and the second direction difference _Sy are calculated.

In Equation 2, P _x and P _y are values obtained by dividing each of the internal resolution values in the direction X and the direction Y of the display device by the number of second direction conductors 4 and first direction conductors 3, respectively.
The electrode position difference calculation unit 13 transmits the first direction difference _Sx and the second direction difference _Sy to the input calculation unit 14 and the rotation angle calculation unit 16.

The input calculation unit 14 calculates the first direction difference S calculated by the electrode position difference calculation unit 13 based on the positions A and B of the first and second electrodes, more specifically, based on the positions A and B. based on _x and the second direction difference _{S y,} and inputs the calculated input value to the LUT 15.

FIG. 5 shows the relationship between the first electrode 101a and the second electrode 101b of the indicator 101 and the inclination deriving device 1 as a coordinate system. The XY plane in FIG. 5 corresponds to the position detectable region 1 a of the tilt deriving device 1.
More specifically, the input calculation unit 14 sets the sensor distance D, which is the distance between the positions of the first and second electrodes 101a and 101b on the sensor 2, to the first electrode 101a and the second electrode in the direction of the axis C. The input value is calculated by dividing by the axial distance L, which is the distance of 101b.

Hereinafter, the direction in which the axis C is inclined from the orthogonal direction Z orthogonal to the sensor 2 is referred to as an inclination direction. In FIG. 5, the inclination θ of the axis C toward the inclination direction is shown as the inclination direction inclination θ.
In this embodiment, after calculating the inclination direction inclination θ, a first direction inclination θ _x and a second direction inclination θ _y described later are derived using the inclination direction inclination θ.
Basically, the on-sensor distance D is calculated as in the following Equation 3, and the inclination in the tilt direction θ _t can be calculated based on this.

FIG. 10 is an explanatory diagram showing the relationship between the input calculation unit 44 and the LUT 45 in the control unit in a modification of the present embodiment described later. The input calculation unit 44 in this modified example calculates the inclination direction inclination θ _t based on the above mathematical formula 3.
As will be described later, an error is included in the inclination direction inclination θ _t calculated by Equation 3, and when this value is used, further correction for eliminating the error is necessary. Are those LUT 45 shown in FIG. 10 performs this correction, the LUT 45, correspondence between the correction value and said inclination direction inclination theta _t are stored. Accordingly, LUT 45 outputs a correction value of the inclination direction inclination theta corresponding to the inputted inclination direction inclination theta _t. That is, the inclination direction inclination θ _t calculated by Equation 3 is merely a provisional value.

Thus, as will be described in more detail later, the LUTs 15 and 45 shown in FIG. 3 and FIG. 10 output the inclination direction inclination correction values for the values calculated by the input calculation units 14 and 44. To do. Therefore, as shown in FIG. 10, the provisional value θ _t calculated by Equation 3 is input, and the input calculation unit 44 is mounted so as to output the correction value of the inclination in the inclination direction, so as to correspond to this. It is also possible to configure the LUT 45.

However, in the present embodiment, as shown in FIG. 3, the input calculation unit 14 calculates the input value I to the LUT 15 as D / L using the following mathematical formula 4. That is, instead of the provisional value θ _t of the inclination in the inclination direction calculated by the above equation 3, the input value I is set as a value calculated based on the positions A and B of the first and second electrodes 101a and 101b. This is calculated and input to the LUT 15. Accordingly, in the LUT 15, not the inclination but a correspondence relation between the value corresponding to the input value I and the inclination direction inclination correction value is registered.

  In the above Equation 3, trigonometric functions that require complicated calculations or special conversion tables on the memory are used. As described above, the input to the LUT 15 is set to a value of I = D / L, and the correspondence between the input value and the correction value including the calculation of the trigonometric function is registered in the LUT 15. The implementation of the conversion table above is omitted.

  The input calculation unit 14 transmits the calculated input value I to the LUT 15 and inputs it.

The LUT 15 includes a first LUT 15A and a second LUT 15B.
In each of the first and second LUTs 15A and 15B, the first and second electrodes when the indicator 101 is tilted from the orthogonal direction Z orthogonal to the sensor 2 toward the first and second directions X and Y, respectively. Each of the first and second input values corresponding to the values calculated based on the positions A and B of each of 101a and 101b, and each of the first and second correction values that are correction values for the inclination of the axis C, Correspondence relationship of is registered.

In the indicator 101, when the first electrode 101a is provided in contact with the sensor 2, the second electrode 101b is positioned away from the sensor 2 as shown in FIG. The detection value by the sensor 2 becomes small. Further, since the second electrode 101b is formed in a larger volume around the axis C than the first electrode 101a, the range that the sensor 2 detects as the second electrode 101b is large. Thus, since the sensor 2 detects a region where small detection values are widely distributed as the position of the second electrode 101b, it is not easy to accurately specify the detection coordinate B of the second electrode 101b. Therefore, the second electrode coordinate value B output from the second IIR filter 12B contains a lot of errors.
For this reason, when the inclination in the inclination direction is derived by Equation 3 as described above, the error described above is reflected in the provisional value θ _{t of the} inclination in the inclination direction thus derived.
Similarly, even when Equation 4 as described above is used, the above error is reflected in the input value I.

Here, if the relationship between the angle at which the indicator 101 is actually tilted and the calculated value including the error of the second electrode coordinate value B and the tilt direction inclination θ is known in advance, from the calculated value including these errors, It should be possible to derive a highly accurate inclination of the indicator 101. That is, the indicator 101 is actually directed in each of the first and second directions X and Y by an inclination derivation device set to output the input value I by the input calculation unit 14 by an experiment or the like. The angle is measured by tilting, and an output value including an error of the input value I at that time is obtained. With respect to this output value, the actual inclination of the indicator 101 is associated as inclination correction values θ ₁ and θ _{2 and} held as a correspondence relationship. When measuring slope actually, the input-calculating section 14 calculates the above equation 4 as a value corresponding to the input value I containing an error in the provisional value theta _t tilt direction tilt. Then, based on this input value I, slope correction values θ ₁ and θ ₂ corresponding to each other in the correspondence relation in the first and second directions X and Y are derived. Thereby, a highly accurate inclination of the indicator 101 can be obtained. Such a correspondence is registered in the LUT 15.

More specifically, the first LUT 15A calculates based on the positions A and B of the first and second electrodes 101a and 101b when the indicator 101 is tilted from the orthogonal direction Z toward the first direction X. a first input value corresponding to the value, the correspondence relationship between the first correction value theta ₁ is a correction value of the slope of the axis C are registered. Here, the value calculated based on the positions A and B of the first and second electrodes 101a and 101b is a mathematical expression when the indicator 101 is tilted from the orthogonal direction Z toward the first direction X. I = D / L value including the error calculated by 4.
In other words, the first correction value θ ₁ tilts the indicator 101 by an angle that is actually tilted toward the first direction X instead of the tilt direction in which the indicator 101 is actually tilted. This is a correction value of the inclination in the first direction X to be output when the input value is used.

Further, the second LUT 15B includes first values corresponding to values calculated based on the positions A and B of the first and second electrodes 101a and 101b when the indicator 101 is tilted in the second direction Y. The correspondence relationship between the two input values and the second correction value θ ₂ that is the correction value of the inclination of the axis C is registered. Here, the value calculated based on the respective positions A and B of the first and second electrodes 101a and 101b is a formula obtained when the indicator 101 is tilted from the orthogonal direction Z toward the second direction Y. I = D / L value including the error calculated by 4.
In other words, the second correction value θ ₂ is obtained by tilting the indicator 101 by an angle that is actually tilted toward the second direction Y instead of the tilt direction in which the indicator 101 is actually tilted. This is a correction value of the inclination in the second direction Y to be output when the input value is used.

That is, the first LUT 15A and the second LUT 15B are directions in which the indicator 101 is actually tilted when the input value I received from the input calculation unit 14 is input as the first and second input values corresponding thereto. Rather, the correction values θ ₁ and θ ₂ of the inclination in the inclination direction in each of the first and second directions X and Y when the inclination is assumed toward the first and second directions X and Y are output. To do. An inclination direction inclination correction value calculation unit 17 described later appropriately performs prorated processing based on the rotation angle of the axis C from the first direction X to the second direction Y with respect to these output values θ ₁ and θ ₂ . As a result, a final inclination direction inclination correction value θ _c is calculated.
In this way, the corrected inclination direction inclinations θ ₁ and θ ₂ in each of the first direction X and the second direction Y are output, and based on this, the final inclination direction inclination correction value θ _c is calculated. Yes. Thereby, even when the length and sensitivity of the unit 2b of the sensor 2 shown in FIG. 5 are different in the first direction X and the second direction Y, the influence is reduced.

6 and 7 show examples of the first LUT 15A and the second LUT 15B. In these tables, the first and second input values are shown as “addresses” in odd-numbered columns from the left. Further, on the right side, that is, in the even-numbered columns, the first and second correction values θ ₁ and θ _{2 of} each inclination in the inclination direction θ are shown as “data”.
In the present embodiment, each of the first and second input values and the first and second correction values θ ₁ and θ ₂ is multiplied by a predetermined value, such as 100. This is for suppressing reduction in calculation accuracy when rounding is performed on integers. Further, the units of the first and second correction values θ ₁ and θ ₂ in the present embodiment are radians (rad).

For example, in FIG. 6, a value “51” is shown as “data” at a position where “address” is “50”. This is because, when the first input value is 0.5, that is, when the inclination in the tilt direction corresponds to 30 °, the first correction value θ ₁ is 0.51 rad, that is, about 29.2 °. Means. In the experiment, when the input value I calculated by the input calculation unit 14 shows a value corresponding to the inclination in the inclination direction 30 °, the inclination in the inclination direction becomes 29.2 ° toward the first direction X. It is shown that the indicator 101 is tilted.

In this embodiment, the first and second input values are realized by 7 bits, for example, and have values up to 127.
As shown in FIG. 1, in the present embodiment, the indicator 101 is gradually tapered from the tip where the first electrode 101a is located in the direction of the axis C, and is formed in a tapered shape. When the angle α with respect to the axis C of the tapered portion is, for example, 25 °, the indicator 101 is set to 25 in a state where the first electrode 101a is in contact with the position detectable region 1a of the tilt deriving device 1. It is impossible to tilt beyond °. For this reason, the upper limits of the first and second correction values θ ₁ and θ ₂ are 1.13 rad corresponding to 65 ° in this case. That is, in the present embodiment, no value exceeding the upper limit value 1.13 rad is registered in the LUT 15.

  In the present embodiment, the measurement experiment on the sensor 2 as described above is performed at a plurality of arbitrary locations on the position detectable region 1a, for example, five locations. More specifically, these five places are, for example, the center of the position detectable region 1a and each of the four corner portions. And the value registered into 1st and 2nd LUT15A, 15B is determined by calculating the average of the value measured by these places. Thereby, the influence of the error due to the difference in values depending on the location on the position detectable region 1a is reduced.

The LUT 15 calculates the first and second correction values θ ₁ and θ ₂ of the inclination in the tilt direction θ based on the input value I received from the input calculation unit 14 according to the correspondence relationship shown in FIGS. Extracted and transmitted to the inclination direction inclination correction value calculation unit 17.

The rotation angle calculation unit 16 calculates the first direction difference calculated by the electrode position difference calculation unit 13 based on the positions A and B of the first and second electrodes, more specifically, based on the positions A and B. Based on S _x and the second direction difference S _y , the rotation angle φ of the axis C from the first direction X to the second direction Y is derived.
The rotation angle corresponds to an angle φ from the first direction X shown in FIG. 5 toward the second direction Y on the XY plane, that is, the position detectable region 1a.
The rotation angle calculation unit 16 derives the rotation angle φ by the following formula 5.

  The rotation angle calculation unit 16 transmits the derived rotation angle φ to the tilt direction inclination correction value calculation unit 17 and outputs it to the outside.

The inclination direction inclination correction value calculation unit 17 receives the first and second correction values θ ₁ and θ ₂ from the first and second LUTs 15A and LUT 15B, and the rotation angle φ from the rotation angle calculation unit 16, respectively.
Inclination direction tilt correction value calculating section 17, the rotation angle phi and the first and second correction value theta _1, from theta _2, the first correction value corresponding to the value of the rotation angle phi theta ₁ and the second correction value theta ₂ the pro rata processing between, calculating a correction value theta _c tilt direction tilt.

  More specifically, the inclination direction inclination correction value calculation unit 17 converts the rotation angle φ into an angle between the first direction X and the second direction Y according to the following equation 6, and calculates the conversion value M. Proportional processing is performed based on this.

ここで、

here,

As can be seen from Equation 6, M is the rotation angle φ converted to an angle between the first direction X and the second direction Y, that is, a value between 0 and π / 2, and N is π / 2. And M is the difference. In the above equation, M is multiplied by the second correction value θ ₂ , and N is multiplied by the first correction value θ ₁ . Thus, when close to the converted value M is larger than the first direction X second direction Y, the second correction value theta ₂ is, the first correction value theta large correction value than _1, corresponding to the second direction Y It is adapted to affect the θ _c. Further, when close to the converted value M is smaller first direction X is, N is increased to the contrary, so as the first correction value theta ₁ corresponding to the first direction X influences the increase correction value theta _c Yes.

Inclination direction tilt correction value calculating section 17, a correction value theta _c of the calculated inclination direction inclination, then transmitted to the first and second directions gradient calculation unit 18 to be described.

The first and second directions inclination calculation section 18, the electrode position difference calculator 13 and the first directional difference S _x the second direction difference S _y, correction value for inclination direction tilt from the inclined direction tilt correction value calculating unit 17 theta _c is received.
The first and second direction inclination calculation unit 18 is orthogonal to the first direction inclination that is the inclination of the axis C from the orthogonal direction Z toward the first direction X, based on the correction value θ _c of the inclination direction inclination. A second direction inclination that is an inclination of the axis C from the direction Z toward the second direction Y is derived.

As described above, in the present embodiment, since the first direction is the direction X shown in FIG. 5, the first direction is the inclination of the axis C from the orthogonal direction Z toward the first direction X on the sensor 2. The one-direction inclination corresponds to the angle θ _x in the XZ plane in FIG. In other words, the first direction inclination θ _x is an inclination of the axis C _x that is a component of the axis C projected from the orthogonal direction Z onto the XZ plane.
Similarly, in the present embodiment, since the second direction is the direction Y shown in FIG. 5, the second direction is the inclination of the axis C from the orthogonal direction Z toward the second direction Y on the sensor 2. The bi-directional tilt corresponds to the angle θ _y in the YZ plane in FIG. The second direction inclination theta _y, in other words, from the orthogonal direction Z, the slope of the axis C _y is the component of the axis C, which is projected to the YZ plane.
The first and second directions inclination calculation section 18, by Equation 7 shown below, from the correction value theta _c tilt direction tilt theta, after computing the height H of the second electrode 101b from the position detecting region 1a, A first direction inclination θ _x and a second direction inclination θ _y are derived.

The first and second direction inclination calculator 18 outputs the derived first direction inclination θ _x and second direction inclination θ _y to the outside.

  Next, an inclination deriving method using the inclination deriving device 1 will be described with reference to FIGS. 1 to 7 and FIG.

When the indicator 101 is positioned on the tilt deriving device 1 such that the first electrode 101 a contacts the position detectable region 1 a of the tilt deriving device 1, the tilt deriving device 1 uses the sensor 2 to detect the first electrode 101 a. Each position of the second electrode 101b is detected.
More specifically, the selection circuit 5 receives the signal transmitted from the indicator 101 to the sensor 2 via each of the first direction conductor 3 and the second direction conductor 4.
The selection circuit 5 transmits signals received from the conductors 3 and 4 to the input data generation unit 6.

  The input data generation unit 6 classifies the signal received from the selection circuit 5 into a signal received from the first electrode 101a of the indicator 101 and a signal received from the second electrode 101b. It transmits to the control part 10 as 2 electrode data.

The first center-of-gravity calculation unit 11A of the control unit 10 receives the first electrode data transmitted from the input data generation unit 6, and the signal transmitted from the first electrode 101a of the indicator 101 is the strongest, that is, the first electrode The coordinate with the strongest response of 101a is specified. The first center-of-gravity calculation unit 11A calculates the first electrode provisional coordinate values A _t (A _xt , A _yt ) from the coordinates with the strongest response of the first electrode 101a.
The first center of gravity calculating section 11A transmits a first electrode provisional coordinate values _{A t} to the IIR filter 12.
Similar to the first centroid calculation unit 11A, the second centroid calculation unit 11B receives the second electrode data, calculates the second electrode provisional coordinate values B _t (B _xt , B _yt ), and outputs the second electrode temporary coordinate values to the IIR filter 12. Send.

The 1IIR filter 12A, from the first center of gravity calculating section 11A receives the first electrode provisional coordinate values _{A t,} by applying a time direction of the IIR filter, calculating a first electrode coordinate value _{A (A} x, _{A y)} To the electrode position difference calculation unit 13.
The second IIR filter 12B receives the second electrode provisional coordinate value B _t from the second centroid calculating unit 11B, and applies the time-direction IIR filter to calculate the second electrode coordinate value B (B _x , B _y ). To the electrode position difference calculation unit 13.

The electrode position difference calculation unit 13 receives the first electrode coordinate value A and the second electrode coordinate value B from the first IIR filter 12A and the second IIR filter 12B.
The electrode position difference calculation unit 13 calculates the first direction difference _Sx and the second direction difference _Sy , and transmits them to the input calculation unit 14 and the rotation angle calculation unit 16.

Input calculation unit 14, based on the first direction difference S _x and the second direction difference S _y calculated by the electrode position difference calculator 13 calculates the input value I by Equation 4 above.
The input calculation unit 14 inputs the calculated input value I to each of the first and second LUT 15A and LUT 15B as the first and second input values.

The first LUT 15A and the second LUT 15B of the LUT 15 have first and second correction values θ ₁ , θ ₂ based on the input value I received from the input calculation unit 14 according to the correspondence relationship shown in FIGS. Is extracted and transmitted to the inclination direction inclination correction value calculation unit 17.

Rotation angle calculation unit 16, based on the first direction difference S _x and the second direction difference S _y calculated by the electrode position difference calculator 13, the rotation from the first direction X of the axis C toward the second direction Y Deriving the angle φ.
The rotation angle calculation unit 16 transmits the derived rotation angle φ to the tilt direction inclination correction value calculation unit 17 and outputs it to the outside.

The inclination direction inclination correction value calculation unit 17 receives the first and second correction values θ ₁ and θ ₂ from the first and second LUTs 15A and LUT 15B, and the rotation angle φ from the rotation angle calculation unit 16, respectively.
Inclination direction tilt correction value calculating section 17, the rotation angle phi and the first and second correction value theta _1, from theta _2, the first correction value corresponding to the value of the rotation angle phi theta ₁ and the second correction value theta ₂ the pro rata processing between, calculating a correction value theta _c tilt direction tilt.
More specifically, the inclination direction inclination correction value calculation unit 17 converts the rotation angle φ into an angle between the first direction X and the second direction Y by Equation 6 to calculate the conversion value M, and based on this. Properly process.
The inclination direction inclination correction value calculation unit 17 transmits the calculated inclination direction inclination correction value θ _c to the first and second direction inclination calculation unit 18.

The first and second directions inclination calculation section 18, the electrode position difference calculator 13 and the first directional difference S _x the second direction difference S _y, correction value for inclination direction tilt from the inclined direction tilt correction value calculating unit 17 theta _c is received.
The first and second direction inclination calculation unit 18 derives the first direction inclination θ _x and the second direction inclination θ _y based on the inclination direction inclination correction value θ _c and outputs them to the outside.

  Next, the effects of the tilt deriving device 1 and the tilt deriving method will be described.

According to the configuration as described above, the correspondence between the provisional value θ _t of the inclination direction inclination θ including the error and the correction value θ _c calculated by the input calculation unit 14 is registered in the LUT 15. .
More specifically, in the present embodiment, the indicator 101 is actually connected to the LUT 15 by an inclination derivation device set to output the input value I externally by the input calculation unit 14 by, for example, experiments. The angle is measured by tilting toward each of the first and second directions X and Y, an output value including an error of the input value I at that time is obtained, and the actual value of the indicator 101 is obtained with respect to this output value. A correspondence relationship in which inclinations are associated as inclination correction values θ ₁ and θ ₂ is stored. That is, the correspondence relationship of the LUT 15 indicates that the inclination value obtained by actually tilting the indicator 101 and the output value of the input calculation unit 14 are respectively calculated as correction values θ ₁ and θ ₂ in the first and second directions X and Y, respectively. It is generated by making it correspond as an input value.
Accordingly, the second electrode coordinates output from the second IIR filter 12B due to factors such as a weak detection value resulting from the second electrode 101b being away from the sensor and a wide detection range resulting from the shape of the second electrode 101b. Even if the input value I calculated based on the value B and the second electrode coordinate value B in the input calculation unit 14 contains a large amount of error, the corrected correction value θ corresponding to this error is eliminated. _1, and stores the theta ₂ first and second 2LUT15A, to 15B, in the inclination direction tilt correction value calculating unit 17 the correction value theta _1, from theta _2, to calculate a correction value theta _c tilt direction tilt. Therefore, the accuracy of the calculated tilt in the tilt direction can be increased, and the tilt of the indicator 101 can be derived with high accuracy.

Further, the first and second LUTs 15A and 15B include first and second correction values that are correction values of the inclination of the axis C when the indicator 101 is tilted in different first and second directions X and Y, respectively. 2 correction values θ ₁ and θ ₂ are stored. Further, the inclination direction inclination correction value calculation unit 17 and the first and second correction values θ ₁ and θ ₂ and the axis C from the first direction X calculated by the rotation angle calculation unit 16 toward the second direction Y are calculated. Based on the rotation angle φ, the inclination correction value θ _c is calculated. That is, if the axis C is whether the tilted in any direction between the first direction X and second direction Y were calculated, inclined correction value by tilting the first direction X theta ₁ to the second direction Y The correction value θ _c for the inclination in the tilt direction is calculated by the proportional processing of the correction value θ ₂ of
Thus, when calculating the correction value theta _c tilt direction inclination, the first correction value theta ₁ and the second respective correction value theta ₂ it can be properly reflected. Therefore, even when the length and sensitivity of the unit 2b of the sensor 2 are different in the first direction X and the second direction Y, the accuracy of the calculated tilt direction tilt is improved, and the tilt of the indicator 101 is accurately derived. can do.

Further, the inclination direction inclination correction value calculation unit 17 converts the rotation angle φ into an angle between the first direction X and the second direction Y, calculates the conversion value M, and apportions based on the conversion value M. Process.
Thereby, especially in the proportional processing, the rotation angle φ is converted into an angle between the first direction X and the second direction Y, so that the proportional processing can be appropriately performed. Therefore, even when the length and sensitivity of the unit 2b of the sensor 2 are different in the first direction X and the second direction Y, the accuracy of the calculated tilt direction tilt is improved, and the tilt of the indicator 101 is accurately derived. can do.

Further, the input calculation unit 14 sets the sensor distance D, which is the distance between the positions of the first and second electrodes 101a and 101b on the sensor 2, as the distance between the first electrode 101a and the second electrode 101b in the axis C direction. The input value I is calculated by dividing by the axial distance L.
According to the configuration as described above, a complicated calculation such as a trigonometric function is not required when calculating the input to the LUT 15, so that the calculation amount and the memory amount can be reduced.

  In the present embodiment, the first and second LUTs 15A and 15B can be realized as a one-dimensional array as shown in FIGS. Therefore, a small amount of memory is required for mounting the first and second LUTs 15A and 15B, and the present invention can be easily applied to hardware having a low memory capacity.

[Experimental result]
Next, the experimental result regarding the said embodiment is demonstrated using FIG.

FIG. 8 is a graph showing the derivation result of the inclination direction inclination in the inclination derivation apparatus 1 in which the length and sensitivity of the unit 2b of the sensor 2 are different in the first direction X and the second direction Y. In each of FIGS. 8A, 8B, 8C, and 8D, the inclination in the tilt direction is measured by setting the rotation angle φ to 0 °, 30 °, 60 °, and 90 °, respectively. . The horizontal axis of each figure in FIG. 8 is the angle at which the indicator 101 is actually tilted with respect to the position detectable region 1a of the tilt deriving device 1, and the vertical axis is the tilt direction tilt value in the tilt deriving device 1. is there.
In each figure of FIG. 8, the line 20 is an ideal value, the lines 21A, 22A, 23A, and 24A are inclination inclinations derived by the calculation of Equation 3, and the lines 21B, 22B, 23B, and 24B are the above inclinations. It is an output value of the deriving device 1.

As the rotation angle φ is 30 °, 60 °, 90 °, and away from 0 °, the lines 22A, 23A, 24A deviate from the line 20, and in particular when the rotation angle φ is 90 °, one unit 2b of the sensor 2 A large error is recognized due to the significant influence of the length anisotropy.
In contrast, the lines 22B, 23B, and 24B are substantially along the line 20, and even when the length and sensitivity of the unit 2b of the sensor 2 are different in the first direction X and the second direction Y. The error is reduced as compared with the lines 22A, 23A, and 24A. That is, it can be seen that the prorated processing using Formula 6 in the tilt direction tilt correction value calculation unit 17 is effectively acting.

[Modification of the above embodiment]
Next, a modified example of the inclination deriving device 1 and the inclination deriving method shown as the embodiment will be described. FIG. 9 is a signal processing block diagram of the control unit 30 of the inclination deriving device in the present modification. The control unit 30 in the inclination deriving device of the present modification is different from the control unit 10 of the inclination deriving device 1 in the above embodiment in that the control unit 30 replaces the first direction inclination θ _x and the second direction inclination θ _y , The difference is that the inclination direction inclination θ is output.
That is, in this modification, the inclination direction tilt correction value calculating section 37, a correction value theta _c of the calculated inclination direction inclination is output to the outside as the inclination direction inclination theta. Further, the control unit 30 does not include the first and second direction inclination calculation units.
It goes without saying that the inclination deriving device and the inclination deriving method in this modification have the same effects as those of the above embodiment.

  The inclination deriving device and the inclination deriving method of the present invention are not limited to the above-described embodiments and modifications described with reference to the drawings, and various other modifications can be considered within the technical scope thereof. .

For example, in the above-described embodiment and modification, the tilt derivation device is a tablet-type information terminal, but is not limited to this, and may be another device including a display device and a sensor, such as a smartphone or a stationary display. Needless to say.
Moreover, in the said embodiment and each modification, although the liquid crystal panel was used as a display apparatus, it is not restricted to this, For example, other display apparatuses, such as an organic electroluminescent display (OLED), may be used. Needless to say.

  Moreover, in the said embodiment and modification, although the 2nd electrode 101b of the indicator 101 was provided in the ring shape so that the axis | shaft C might be enclosed, it is not restricted to this. For example, a plurality of second electrodes having the same function may be formed in a ring shape as a result of being provided apart from each other in the circumferential direction about the axis C, or may be aligned in other manners. It doesn't matter.

  Moreover, in the said embodiment, although the 1st direction X and the 2nd direction Y were mutually orthogonal, you may cross | intersect at angles other than 90 degrees. Even in such a case, it can be dealt with, for example, by adjusting the prorated processing angle in Equation 6.

Further, in the above-described embodiment and modification, the correspondence between the value corresponding to the input value I and the correction value of the inclination in the tilt direction, which is represented by Expression 4, is registered in the LUT 15. Instead, as already described with reference to FIG. 10 in the above embodiment, the input calculation unit 44 outputs the provisional value θ _{t of the} inclination in the inclination direction, which is expressed by Equation 3, and the provisional value θ _t The LUT 45 may be configured so that the correspondence relationship with the inclination direction inclination correction value is registered.
Also in this case, the LUT 45 includes the first LUT 45A and the second LUT 45B as in the above embodiment.
The first LUT 45A includes a first input value corresponding to the provisional value θ _t calculated by Equation 3 and a correction value for the tilt of the axis C when the indicator is tilted from the orthogonal direction Z toward the first direction X. correspondence between the first correction value theta ₁ is is registered.
The second LUT 45B includes a second input value corresponding to the provisional value θ _t calculated by Equation 3 and a correction value for the tilt of the axis C when the indicator is tilted in the second direction Y. correspondence between the second correction value theta ₂ is registered.

In addition to this, the configurations described in the above-described embodiments and modifications may be selected or changed to other configurations as appropriate without departing from the gist of the present invention.
For example, the control unit simultaneously includes both the first and second direction inclination calculation unit 18 of the above embodiment and the inclination direction inclination correction value calculation unit 37 of the modification, and the first direction inclination θ _x and the second direction inclination You may output (theta) _y and inclination direction inclination (theta) all outside.

DESCRIPTION OF SYMBOLS 1 Inclination derivation | leading-out apparatus 2 Sensor 10, 30 Control part 14 Input calculation part 15A 1st LUT (1st lookup table)
15B Second LUT (second lookup table)
16 Rotation angle calculation unit 17, 37 Inclination direction inclination correction value calculation unit 18 First and second direction inclination calculation unit 101 Indicator 101a First electrode 101b Second electrode A First electrode position B Second electrode position C Axis D sensor upper distance I input value L axial distance X first direction Y second direction Z orthogonal direction θ inclination direction inclination φ rotation angle θ ₁ first correction value θ ₂ second correction value θ _c inclination direction inclination correction value θ _x first direction inclination θ _y second direction inclination

Claims (12)

An inclination deriving device for deriving the inclination of a pen-shaped indicator,
The indicator includes a first electrode provided at one end in the axial direction and a second electrode provided around the axis,
A planar sensor for detecting the position of the first electrode, the position of the second electrode, and a control unit;
The control unit
A first value corresponding to a value calculated based on the position of each of the first and second electrodes when the indicator is tilted from an orthogonal direction orthogonal to the sensor toward a first direction on the sensor. A first lookup table in which a correspondence relationship between one input value and a first correction value that is a correction value of the inclination of the axis is registered;
A second value corresponding to a value calculated based on the position of each of the first and second electrodes when the indicator is tilted in a second direction different from the first direction on the sensor; A second lookup table in which a correspondence relationship between an input value and a second correction value that is a correction value of the inclination of the axis is registered;
An input calculation unit that calculates an input value based on the position of each of the first and second electrodes and inputs the input value to the first and second look-up tables as the first and second input values;
A rotation angle calculation unit for deriving a rotation angle of the shaft from the first direction toward the second direction based on the position of each of the first and second electrodes;
An inclination direction inclination correction value calculation unit that calculates an inclination direction inclination correction value that is an inclination of the axis from the orthogonal direction toward the direction in which the axis is inclined from the rotation angle and the first and second correction values; ,
An inclination derivation device comprising:   The inclination direction inclination correction value calculation unit calculates the correction value of the inclination direction inclination by a prorated process between the first correction value and the second correction value according to the rotation angle value. The inclination deriving device according to claim 1.   The inclination direction inclination correction value calculation unit converts the rotation angle into an angle between the first direction and the second direction, calculates a conversion value, and performs the proration processing based on the conversion value. The inclination deriving device according to claim 2, wherein   The input calculation unit calculates a sensor distance, which is a distance between the positions of the first and second electrodes on the sensor, and an axial direction, which is a distance between the first electrode and the second electrode in the axial direction. The slope derivation device according to claim 1, wherein the input value is calculated by dividing by a distance.   Based on the correction value of the inclination direction inclination calculated by the inclination direction inclination correction value calculation unit, a first direction inclination that is an inclination of the axis from the orthogonal direction toward the first direction, and the orthogonality 5. The apparatus according to claim 1, further comprising first and second direction inclination calculation units that derive a second direction inclination that is an inclination of the axis from the direction toward the second direction. 6. Tilt derivation device.   The inclination derivation device according to claim 1, wherein the inclination direction inclination correction value calculation unit outputs the calculated correction value of the inclination direction inclination as the inclination direction inclination. An inclination derivation method for deriving an inclination indicated by a pen-shaped indicator,
The planar sensor detects the position of each of the first electrode provided at one end in the axial direction of the indicator and the second electrode provided so as to surround the axis,
Calculating an input value based on the position of each of the first and second electrodes;
A first value corresponding to a value calculated based on the position of each of the first and second electrodes when the indicator is tilted from an orthogonal direction orthogonal to the sensor toward a first direction on the sensor. Input the input value as the first input value to a first lookup table in which a correspondence relationship between one input value and a first correction value that is a correction value of the tilt of the axis is registered;
A second value corresponding to a value calculated based on the position of each of the first and second electrodes when the indicator is tilted in a second direction different from the first direction on the sensor; The input value is input as the second input value to a second lookup table in which a correspondence relationship between the input value and the second correction value that is a correction value of the tilt of the axis is registered,
Based on the position of each of the first and second electrodes, a rotation angle of the shaft from the first direction toward the second direction is derived,
An inclination direction inclination that is an inclination of the axis from the orthogonal direction toward the direction in which the axis is inclined from the rotation angle and the first and second correction values output from the first and second look-up tables. An inclination derivation method for calculating a correction value of.   The inclination derivation method according to claim 7, wherein the correction value of the inclination in the inclination direction is calculated by proration processing between the first correction value and the second correction value according to the value of the rotation angle. .   The inclination according to claim 8, wherein the rotation angle is converted into an angle between the first direction and the second direction to calculate a conversion value, and the proration processing is performed based on the conversion value. Derivation method.   The distance on the sensor, which is the distance between the positions of the first and second electrodes on the sensor, is divided by the axial distance, which is the distance between the first electrode and the second electrode in the axial direction, The slope derivation method according to claim 7, wherein the input value is calculated.   Based on the correction value of the tilt direction tilt, the first direction tilt that is the tilt of the axis from the orthogonal direction toward the first direction and the second direction from the orthogonal direction. The inclination derivation method according to claim 7, wherein a second direction inclination that is an inclination of the axis is derived.   12. The tilt derivation method according to claim 7, wherein the calculated correction value of the tilt direction tilt is output as the tilt direction tilt.

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