WO2013094571A1

WO2013094571A1 - Touch panel unit and touch assessment method

Info

Publication number: WO2013094571A1
Application number: PCT/JP2012/082702
Authority: WO
Inventors: 岡田　厚志
Original assignee: シャープ株式会社
Priority date: 2011-12-22
Filing date: 2012-12-17
Publication date: 2013-06-27

Abstract

The objective of the present invention is to achieve a touch panel capable of accurately assessing touches and non-touches without being affected by the size of the tip portion of a pen or the like which touches the touch panel. This touch panel unit (1) is provided with: a touch panel (2) which has a substrate (11), Y-direction electrodes (21) and X-direction electrodes (22); and a controller (3) which detects touches and non-touches by comparing a sensor signal output from one of the electrodes with a threshold. The controller (3) is provided with: a storage unit (33) in which reference values at a plurality of reference positions upon the substrate (11) are stored; a touch position estimation unit (31) for estimating a touch position on the basis of the sensor signal; a threshold correction unit (34) for correcting the threshold using the reference values; and a touch assessment unit (35) which uses the value corrected by the threshold correction unit (34) to assess the touches and non-touches.

Description

Touch panel unit and touch determination method

The present invention relates to a touch panel unit capable of detecting a touch position on an operation surface of a touch panel.

A touch panel unit that can detect a position touched by a pen or a finger on the operation surface of the touch panel, that is, a touch position is known. Such a touch panel has a plurality of first electrodes and second electrodes extending in directions crossing each other on a substrate, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-160670.

Thereby, in the configuration disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2010-160670, capacitance is formed between the finger touching the touch panel and the first electrode and the second electrode, respectively. By detecting these capacitances as signals of the first electrode or the second electrode, the touch position on the operation surface can be detected.

By the way, in a touch panel having a configuration as disclosed in JP 2010-160670 A, when a touch is performed using a pen, the relationship between the size of the tip of the pen and the pitch of the first electrode and the second electrode However, this affects the detection accuracy of pen touch and non-touch.

That is, when the outer diameter of the tip of the pen is smaller than the pitch of the electrodes on the touch panel, the signal output from each electrode of the touch panel varies depending on the position where the pen touches the touch panel. Generally, the determination that the pen is touching the touch panel is made based on whether or not the signal output from each electrode is greater than a threshold value. As described above, if the signal output from each electrode differs depending on the position touched by the pen, the variation in the output signal with respect to the threshold value may increase, and the determination of touch and non-touch may also vary. is there. In this case, it is determined that the pen is not touching the touch panel but is actually touched, or the pen is touching the touch panel but is not touched. become.

Therefore, an object of the present invention is to obtain a touch panel unit that can determine touch and non-touch more accurately without being affected by the size of the tip portion of a pen or the like that touches the touch panel.

A touch panel unit according to an embodiment of the present invention includes a substrate, a first electrode formed on the substrate so as to extend in one direction, and formed on the substrate so as to extend in a direction intersecting the first electrode. And a touch detection unit that detects touch and non-touch by comparing a sensor signal output from the first electrode or the second electrode with a threshold value. The detection unit touches a signal output from the first electrode or the second electrode when a plurality of reference positions on the substrate are touched, and one reference position among the plurality of reference positions. In this case, a reference value that is a ratio to a signal output from the first electrode or the second electrode is stored in a readable manner on the substrate based on the sensor signal. A touch position estimation unit that estimates a touch position; a correction unit that corrects one of the sensor signal and the threshold value at the touch position using the reference value; a value that is corrected by the correction unit and the sensor; A touch determination unit that compares the signal and the uncorrected value of the threshold value to determine touch and non-touch;

The touch panel unit according to an embodiment of the present invention can determine touch and non-touch more accurately without being affected by the size of the tip portion of a pen or the like that touches the touch panel.

FIG. 1 is a diagram schematically illustrating the overall configuration of the touch panel unit according to the first embodiment. FIG. 2 is a plan view showing a schematic configuration of the touch panel. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a diagram illustrating an example of coordinate positions on the touch panel. FIG. 5 is a diagram illustrating an example of the distribution of touch signals at each reference position when the pen touches at each reference position in one sensor area. FIG. 6 is a diagram in which the positions estimated as the reference positions and the touch positions shown in FIG. 5 are displayed in the XY coordinate system. FIG. 7 is a diagram illustrating a difference between the touch signal having the distribution illustrated in FIG. 5 and a threshold value. FIG. 8 is a diagram illustrating a difference between the touch signal having the distribution illustrated in FIG. 5 and the corrected threshold value. FIG. 9 is a diagram illustrating a flow of determining a touch on the touch panel. FIG. 10 is a diagram illustrating an example of reference values stored in the storage unit in the touch panel unit according to the modification. FIG. 11 is a diagram schematically illustrating the overall configuration of the touch panel unit according to the second embodiment.

A touch panel unit according to an embodiment of the present invention includes a substrate, a first electrode formed on the substrate so as to extend in one direction, and formed on the substrate so as to extend in a direction intersecting the first electrode. And a touch detection unit that detects touch and non-touch by comparing a sensor signal output from the first electrode or the second electrode with a threshold value. The detection unit touches a signal output from the first electrode or the second electrode when a plurality of reference positions on the substrate are touched, and one reference position among the plurality of reference positions. In this case, a reference value that is a ratio to a signal output from the first electrode or the second electrode is stored in a readable manner, and the substrate is based on the sensor signal. A touch position estimator that estimates the touch position, a correction unit that corrects one of the sensor signal and the threshold at the touch position using the reference value, a value corrected by the correction unit, and the A touch determination unit that compares the sensor signal and an uncorrected value among the threshold values and determines whether to touch or not (first configuration).

In the above configuration, the sensor signal output from the first electrode extending in one direction on the substrate or the second electrode extending in the direction intersecting with the first electrode is compared with a threshold value, thereby touching the touch panel and Detect non-touch. Then, by correcting any one of the sensor signal and the threshold value at the touch position estimated by the touch position estimation unit using the reference value of the reference position stored in the storage unit, the touch position other than the touch position on the substrate is corrected. The touch and non-touch determination can be performed in consideration of the point. That is, the reference value is a ratio between a signal output from the first electrode or the second electrode when a plurality of reference positions are touched and the signal at one reference position among the plurality of reference positions. , The relative value of the output signal at each position on the substrate. By correcting one of the sensor signal and the threshold value at the touch position using the reference value, the difference between the sensor signal and the threshold value can be corrected to a value corresponding to the relative value. Thereby, compared with the difference between the sensor signal before correction and the threshold value, variation in the difference depending on the touch position can be reduced.

The first configuration further includes a correction coefficient calculation unit that calculates a correction coefficient at the touch position using the reference value, and the correction unit uses the correction coefficient to detect the sensor signal and the touch position at the touch position. Either one of the threshold values is corrected (second configuration).

Thus, a correction coefficient for correcting either the sensor signal or the threshold value can be obtained using the reference value that is a relative value. By obtaining such a correction coefficient, either the sensor signal or the threshold value at the touch position can be easily corrected.

In the second configuration, the correction coefficient calculation unit obtains the correction coefficient at the touch position using reference values at a plurality of reference positions surrounding the touch position (third configuration).

In this way, the correction coefficient at the touch position can be calculated with higher accuracy using the reference values at the plurality of reference positions surrounding the portion estimated as the touch position by the touch position estimation unit.

In the third configuration, the correction coefficient calculation unit calculates a reference value between two reference positions arranged in one direction and two reference positions arranged in the other direction among the four reference positions surrounding the touch position. The correction coefficient at the touch position is obtained using a reference value (fourth configuration).

Thereby, the correction coefficient at the touch position estimated by the touch position estimation unit can be obtained with higher accuracy by using the reference value of the reference position located around the correction coefficient.

In any one of the second to fourth configurations, the correction coefficient calculation unit obtains the correction coefficient of the touch position by linear interpolation using reference values at a plurality of reference positions (fifth). Configuration).

In this way, the correction coefficient at the touch position estimated by the touch position estimation unit can be easily calculated using the reference values at a plurality of reference positions.

In any one of the second to fifth configurations, the correction unit corrects the threshold value using the correction coefficient at the touch position, and the touch determination unit includes the corrected threshold value. And the sensor signal are compared to determine touch or non-touch (sixth configuration).

In the touch determination method for a touch panel according to an embodiment of the present invention, a sensor signal output from a touch panel arranged on a substrate so that a first electrode extending in one direction and a second electrode extending in the other direction intersect. The touch position of the touch panel is estimated based on the signal, a signal output from the touch panel when a plurality of reference positions on the touch panel are touched, and one reference position of the plurality of reference positions is touched. In this case, the sensor signal at the touch position and a threshold value for determining touch and non-touch are corrected using a reference value that is a ratio with a signal output from the touch panel. , Touch and non-touch by comparing the corrected value with the uncorrected value of the sensor signal and the threshold A determination (7 method).

Hereinafter, a preferred embodiment of the touch panel unit will be described with reference to the drawings. In addition, the dimension of the structural member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each structural member, etc. faithfully.

[Embodiment 1]
(overall structure)
FIG. 1 shows a schematic configuration of a touch panel unit 1 according to an embodiment of the present invention. As shown in FIG. 1, the touch panel unit 1 includes a touch panel 2 and a controller 3 (touch detection unit) for detecting a touch position on the touch panel 2. In the touch panel unit 1 having such a configuration, the touch panel 2 is superimposed on a display device such as a liquid crystal display device.

As shown in FIG. 2, the touch panel 2 includes touch electrodes 12 arranged on the operation surface so that the position where the operation surface is touched can be detected. The touch panel 2 according to the present embodiment utilizes the fact that electrostatic capacitance is formed between the touch electrode 12 and the pen 4 that touches the operation surface, thereby static electricity between the touch electrode 12 and the pen 4 depending on the touch position. The touch position is determined from the difference in electric capacity. That is, the touch panel 2 of the present embodiment is a so-called capacitance type touch panel.

Specifically, as shown in FIG. 3, the touch panel 2 includes a substrate 11, a touch electrode 12 formed on one surface side (operation surface side, viewing side) of the substrate 11, the touch electrode 12 and the substrate 11. And an insulating layer 13 formed between and a protective layer 14 for protecting the touch electrode 12. As shown in FIG. 2, the touch electrode 12 includes a plurality of

electrode pads

21a and 22a formed in a substantially square shape in plan view and a plurality of

electrode pads

21c and 22b formed in a substantially triangular shape. These

electrode pads

21a, 22a, 21c, and 22b are configured by being arranged at almost equal intervals on the entire operation surface. 2 and 3, illustration of the cover glass and the like covering the touch surface side of the touch panel 2 is omitted.

The touch electrode 12 includes an X-direction electrode 22 (second electrode) extending in the X direction (other direction) and a Y-direction electrode 21 (first electrode) extending in the Y direction (one direction) (see FIG. 2). The X direction electrode 22 and the Y direction electrode 21 are made of a light-transmitting conductive material (transparent conductive material) such as ITO (indium tin oxide). As shown in FIG. 2, the X direction and the Y direction are directions that intersect each other on the plane of the substrate 11. In FIG. 1, the center line 21d in the width direction of the Y-direction electrode 21 and the center line 22c in the width direction of the X-direction electrode 22 are indicated by broken lines. In FIG. 2, the number of the X direction electrodes 22 and the Y direction electrodes 21 is smaller than that in FIG.

The Y-direction electrode 21 is formed by integrally forming a substantially square Y-direction electrode pad 21a in plan view and a connection portion 21b that connects adjacent Y-direction electrode pads 21a. That is, the Y-direction electrode 21 has a shape extending in the Y direction in FIG.

Specifically, the Y-direction electrode 21 is such that the corner portions of the Y-direction electrode pad 21a are connected by the connecting portion 21b in a state where the plurality of Y-direction electrode pads 21a are arranged so that the diagonal line coincides with the Y direction. Has a shape. The Y direction electrode 21 is formed such that a plurality of Y direction electrode pads 21a are arranged at equal intervals in the Y direction. A plurality of Y-direction electrodes 21 are provided side by side in the X direction.

It should be noted that a substantially triangular Y-direction electrode pad 21c is provided at both ends in the longitudinal direction of the Y-direction electrode 21 in plan view. That is, the Y-direction electrode pads 21c located at both ends in the longitudinal direction of the Y-direction electrode 21 are approximately half the size of the other Y-direction electrode pads 21a.

As shown in FIG. 2, the X-direction electrode 22 is adjacent to the X-direction electrode pad 22a having a substantially rectangular shape and the same size as the Y-direction electrode pad 21a, as with the Y-direction electrode pad 21a described above. And a bridge portion 23 for connecting the X-direction electrode pads 22a. Specifically, the X-direction electrode 22 is configured by connecting the corner portions of a plurality of X-direction electrode pads 22 a arranged so that the diagonal line coincides with the X direction by the bridge portion 23.

The X direction electrode pads 22a are arranged at regular intervals in the X direction. Further, the X-direction electrode pad 21a is disposed so as to sandwich the connecting portion 21b of the Y-direction electrode 21 between adjacent corner portions. Thereby, as shown in FIG. 2, the Y-direction electrode pad 21a and the X-direction electrode pad 22a are arranged on the entire operation surface at equal intervals.

As in the Y-direction electrode pad 21c located at both longitudinal ends of the Y-direction electrode 21 described above, substantially triangular X-direction electrode pads 22b are provided at both longitudinal ends of the X-direction electrode 22. . That is, the X-direction electrode pads 22b located at both ends in the longitudinal direction of the X-direction electrode 22 are about half the size of the other X-direction electrode pads 22a.

The

X-direction electrode pads

22 a and 22 b of the X-direction electrode 22 are connected to the adjacent

X-direction electrode pads

22 a and 22 b with the Y-direction electrode 21 interposed therebetween by the bridge portion 23. As shown in FIG. 3, the bridge portion 23 that connects adjacent

X-direction electrode pads

22 a and 22 b is disposed so as to straddle the connection portion 21 b of the Y-direction electrode 21.

The

X-direction electrode pads

22a and 22b are made of a transparent conductive material such as ITO, for example, like the Y-direction electrode 21.

The bridge portion 23 is made of a transparent conductive material such as ITO, for example, like the Y-direction electrode 21 and the

X-direction electrode pads

22a and 22b. As shown in FIG. 2, the bridge portion 23 is formed in a rectangular shape when viewed from the normal direction of the substrate 11.

As shown in FIG. 2, a lead-out wiring 24 is connected to substantially

triangular electrodes

21c and 22b located on one end side in the longitudinal direction of the Y-direction electrode 21 and the X-direction electrode 22. The lead wiring 24 is made of a metal material such as an aluminum alloy, for example. The lead-out wiring 24 is formed so that the end opposite to the end connected to the Y-direction electrode 21 and the X-direction electrode 22 gathers on one side of the substrate 11. A terminal 25 for outputting a signal to an external control circuit is formed at the end of the collected lead wiring 24.

(controller)
As shown in FIG. 1, the controller 3 is electrically connected to the touch panel 2 by wiring 5. For example, the controller 3 applies a voltage to the X direction electrode 22 and reads a current value output from the Y direction electrode 21. The wiring 5 inputs the current value output from the Y-direction electrode 21 when the pen 4 is brought close to the touch panel 2 to the controller 3 as an output signal (sensor signal). Note that the wiring 5 is electrically connected to the terminal 25 of the touch panel 2.

Controller 3 determines whether pen 4 touched touch panel 2 or not touched (touch and non-touch) based on the output signal when pen 4 is brought close to touch panel 2.

When the diameter of the tip portion of the pen 4 is smaller than the pitch of the Y-direction electrodes 21 (interval between center lines of adjacent electrodes, hereinafter the same) or the pitch of the X-direction electrodes 22, the touch position of the pen 4 is slightly shifted. As a result, the output signal from the Y-direction electrode 21 changes greatly. That is, the signal output from the Y-direction electrode 21 varies greatly depending on whether or not the Y-direction electrode 21 is included in the region where the tip portion of the pen 4 approaches. Then, when touch and non-touch are determined based on a certain threshold, if the touch position is slightly shifted, it may be determined that the touch is not touched. That is, when the size of the tip portion of the pen 4 is smaller than the pitch of the Y-direction electrode 21 or the pitch of the X-direction electrode 22, there is a possibility that the touch / non-touch determination accuracy of the pen 4 is lowered.

On the other hand, even when the diameter of the tip portion of the pen 4 is smaller than the pitch of the Y direction electrode 21 or the pitch of the X direction electrode 22, the controller 3 accurately determines whether the pen 4 is touched or not touched. It is configured to be able to.

Specifically, the controller 3 includes a touch position estimation unit 31, a correction coefficient calculation unit 32, a storage unit 33, a threshold correction unit 34 (correction unit), a touch determination unit 35, and a coordinate output unit 36.

The touch position estimation unit 31 estimates the position where the pen 4 is brought close to the touch panel 2 based on the output signal. That is, when the output signal output from the Y-direction electrode 21 is equal to or greater than a predetermined value, the touch position estimation unit 31 specifies the position where the output signal is obtained on the touch panel 2 and sets the position on the touch panel 2. On the other hand, it is estimated that the pen 4 is touching.

Specifically, the touch position estimation unit 31 includes a coordinate position detection unit 31a and a position calculation unit 31b. The coordinate position detection unit 31 a detects the Y direction position and the X direction position of the touch panel 2 as coordinate positions based on the output signal output from the Y direction electrode 21. That is, when the output signal output from the Y-direction electrode 21 is equal to or greater than a predetermined value, the coordinate position detection unit 31a specifies the coordinate position where the output signal is obtained on the touch panel 2. Note that the coordinate position on the touch panel 2 is defined by coordinates in the X direction (horizontal direction in the figure) and coordinates in the Y direction (vertical direction in the figure), as shown in FIG. In the example of FIG. 4, (210, 380) is the coordinate position where the output signal is obtained on the touch panel 2.

The position calculation unit 31b uses the coordinate position detected by the coordinate position detection unit 31a to obtain a position where the output signal is equal to or greater than a predetermined value (position estimated as a touch position). Specifically, the position calculation unit 31b uses the dimensions per unit coordinate in the X direction and the Y direction (values obtained by dividing the panel dimensions in the X direction and the Y direction by a preset number of coordinates), and the touch position. It is determined which position is estimated within one sensor area (area surrounded by the center line of adjacent electrodes). The position calculation unit 31b calculates the dimensions in the X direction and the Y direction based on the reference point (the upper left corner in the sensor area in the example of FIG. 4) in one sensor area indicated by hatching in FIG. Find x and y.

x = Tx−INT (Tx / Px) × Px
y = Ty−INT (Ty / Py) × Py
Here, Tx is a position in the X direction estimated as a touch position, and is a coordinate value in the X direction to a dimension per unit coordinate in the X direction (a value obtained by dividing the panel dimension in the X direction by the number of coordinates in the X direction). Is obtained by multiplying by. Ty is a position in the Y direction estimated as a touch position, and a dimension per unit coordinate in the Y direction (a value obtained by dividing a panel dimension in the Y direction by the number of coordinates in the Y direction) is multiplied by a coordinate value in the Y direction. Can be obtained. Px is an interval (pitch) between the center lines 22c of the adjacent X direction electrodes 22, and Py is an interval (pitch) between the center lines 21d of the adjacent Y direction electrodes 21. INT is a function for obtaining an integer from a numerical value in parentheses.

The correction coefficient calculation unit 32 calculates a correction coefficient for correcting a threshold used for discrimination between touch and non-touch at the position (x, y) estimated by the touch position estimation unit 31 and estimated as the touch position. . The correction coefficient calculation unit 32 calculates the correction coefficient at the position estimated as the touch position, using the reference values at a plurality of reference positions (9 points in the present embodiment) in one sensor area. The reference positions are preferably determined so as to be equally spaced in the X direction and the Y direction within one sensor region. The reference value is a value corresponding to a signal (hereinafter referred to as a touch signal) output from the touch panel 2 when the pen 4 touches the reference position of the touch panel 2 and is stored in the storage unit 33. FIG. 5 shows an example of the distribution of touch signals at each position in one sensor area when the pen 4 touches the touch panel 2. In FIG. 5, positions obtained by dividing one sensor area into three equal parts in the X direction are x1, x2, and x3, respectively, and positions obtained by dividing the one sensor area into three equal parts in the Y direction are y1, y2, and y3, respectively. In FIG. 5, the positions of nine points from (x1, y1) to (x3, y3) are the reference positions.

The storage unit 33 stores not the touch signal data shown in FIG. 5 but the ratio of the touch signal at each reference position when the touch signal at one reference position is used as a reference value. In FIG. 5, the vertical axis represents the signal magnitude.

For example, when the position estimated as the touch position is a coordinate (x, y) indicated by a white circle in FIG. 6, the correction coefficient calculation unit 32 obtains a correction coefficient by the following equation. That is, the correction coefficient calculation unit 32 uses the reference values of the four reference positions surrounding the position estimated as the touch position for the points other than the points stored in advance in the storage unit 33, and the X direction (the other direction) and A correction coefficient is obtained by performing linear interpolation in the Y direction (one direction). Thereby, the correction coefficient in the position estimated as the touch position can be easily obtained. In addition, what is necessary is just to change according to the four coordinate points used when performing linear interpolation so that it may become four points surrounding the coordinate position which calculates | requires a correction coefficient. In FIG. 6, the shaded area corresponds to the one sensor area described above.

X1 = S (x1, y2) − (S (x1, y2) −S (x2, y2))
/ (X2-x1) × x
X2 = S (x1, y3) − (S (x1, y3) −S (x2, y3))
/ (X2-x1) × x
Q = X1- (X1-X2) / (y3-y2) × (y-y2)
Here, S is a value representing the touch signal at each coordinate position (black circle) in FIG. 6 as a ratio with the touch signal of (x1, y1) as a reference, and corresponds to the above-described reference value. X1 and X2 each indicate an interpolation value in the X direction at the coordinate x. Q indicates a correction coefficient at coordinates (x, y) in consideration of the X direction and the Y direction.

When the position estimated as the touch position is a point stored in advance in the storage unit 33, that is, when the position estimated as the touch position is the reference position, the correction coefficient calculation unit 32 determines the reference position. Is output as the correction coefficient Q.

The threshold correction unit 34 corrects the threshold at the coordinates (x, y) using the correction coefficient Q calculated by the correction coefficient calculation unit 32 as described above. Specifically, the threshold correction unit 34 multiplies the correction threshold Q obtained as described above by multiplying the threshold set in advance for performing the touch and non-touch determinations, thereby obtaining the corrected threshold. calculate. Thereby, the threshold value for discriminating touch and non-touch can be corrected according to the position of the tip portion of the pen 4. Therefore, it is possible to prevent variations in determination of touch and non-touch depending on the touch position of the tip portion of the pen 4.

It is also clear from the graphs shown in FIGS. 7 and 8 that the configuration of this embodiment as described above can prevent variations in touch and non-touch determinations depending on the touch position. FIG. 7 is a graph showing the difference between the touch signal and the threshold value (constant) at each touch position (25 points from (x1, y1) to (x5, y5)) in one sensor area. FIG. 8 is a graph showing the difference between the corrected threshold value and the touch signal at each touch position in one sensor area when the threshold value is corrected as described above. 7 and 8, the positions obtained by dividing one sensor area into 5 parts in the X direction are x1 to x5, respectively, and the positions obtained by dividing the one sensor area into 5 parts in the Y direction are respectively y1 to y5. .

As shown in FIG. 7, when the determination is simply made with a certain threshold value, the difference between the output signal and the threshold value varies greatly depending on the touch position of the pen 4. Cheap. On the other hand, as shown in FIG. 8, by correcting the threshold according to the touch position, variation in the difference between the output signal and the threshold depending on the touch position is reduced, so that touch and non-touch determination accuracy is improved. Can be planned.

The touch determination unit 35 determines whether the output signal output from the Y-direction electrode 21 is larger than the threshold value corrected by the threshold value correction unit 34. The touch determination unit 35 determines that the pen 4 is touching the touch panel 2 when the output signal is larger than the corrected threshold value.

The coordinate output unit 36 outputs the coordinates of the touch position when the touch determination unit 35 determines that the pen 4 is touching the touch panel 2.

(Touch judgment method)
Next, a method for determining whether or not the pen 4 has touched the touch panel 2 in the touch panel unit 1 having the above-described configuration will be described using the flow of FIG.

First, when the flow shown in FIG. 9 starts (start), as shown in step S1, the coordinate position detection unit 31a of the touch position estimation unit 31 of the controller 3 acquires coordinate data of a position estimated to be touched. . At this time, the coordinate position detection unit 31a determines the coordinate position estimated to be touched by determining whether the output signal output from the Y-direction electrode 21 is equal to or greater than a predetermined value.

Next, in step S2, the position calculation unit 31b of the touch position estimation unit 31 calculates the position on the touch panel 2 from the coordinate data of the position estimated as the touch position. Specifically, the position calculation unit 31b obtains an approximate position from the coordinate data and obtains a position (dimensional position) estimated as a touch position within one sensor region. Thereby, the position estimated as the touch position on the touch panel 2 can be obtained.

In step S3, the correction coefficient calculation unit 32 first determines whether or not the position estimated as the touch position (simply described as simply the touch position in FIG. 9) is a reference position stored in advance in the storage unit 33. When the position estimated as the touch position is the reference position (in the case of YES), the process proceeds to step S4, and the reference value of the reference position is set as the correction coefficient Q. On the other hand, when the position estimated as the touch position is not the reference position (in the case of NO), the process proceeds to step S5 and thereafter, and the correction coefficient Q at the position estimated as the touch position is calculated.

In step S5, the correction coefficient calculation unit 32 extracts four reference positions surrounding the position estimated as the touch position. In subsequent step S6, the correction coefficient calculation unit 32 calculates the correction coefficient Q of the position estimated as the touch position using the extracted reference value of the reference position.

After obtaining the correction coefficient Q at the position estimated as the touch position in Steps S4 and S6, the threshold value after correction is calculated by using the correction coefficient Q by the threshold value correction unit 34 in Step S7.

In subsequent step S8, the touch determination unit 35 determines whether or not the output signal output from the Y-direction electrode 21 is larger than the corrected threshold value. If it is determined in step S8 that the output signal is greater than the corrected threshold value (in the case of YES), the process proceeds to step S9 where the coordinate output unit 36 outputs the coordinates of the touch position. On the other hand, when it is determined in step S8 that the output signal is not larger than the corrected threshold value (in the case of NO), it is determined as non-touch and this flow is ended (END).

(Effect of Embodiment 1)
In this embodiment, the controller 3 estimates that the touch panel 2 is touched with the pen 4 when the output signal output from the Y-direction electrode 21 of the touch panel 2 is a predetermined value or more. Further, the controller 3 obtains the position estimated as the touch position in this way, and obtains the correction coefficient using the reference values of four points surrounding the position estimated as the touch position. The controller 3 multiplies the obtained correction coefficient by a threshold value for determining touch and non-touch to correct the threshold value, and when the output signal is larger than the corrected threshold value, the pen 4 is applied to the touch panel 2. It determines that it is touching.

With the above configuration, even when the diameter of the tip portion of the pen 4 is smaller than the pitch of the Y-direction electrodes 21 or the pitch of the X-direction electrodes 22 of the touch panel 2, variations in touch and non-touch determinations depending on the touch position can be reduced. That is, by correcting the threshold value used for determination of touch and non-touch according to the touch position, determination of touch and non-touch can be performed in consideration of variations in the output signal depending on the touch position.

(Modification of Embodiment 1)
FIG. 10 shows a distribution of reference values stored in the storage unit 33 in the controller 3 of the touch panel unit 1 according to the modification of the first embodiment. In FIG. 10, the positions obtained by dividing one sensor region into five equal parts in the X direction are x1 to x5, respectively, and the positions obtained by dividing the one sensor area into five parts in the Y direction are y1 to y5, respectively. In FIG. 10, the positions of 25 points from (x1, y1) to (x5, y5) are reference positions.

In this modified example, unlike the above-described first embodiment, a total of 25 reference values in which 5 points are arranged in the X direction and the Y direction are stored in the storage unit 33 in one sensor area. In this modified example, the correction coefficient calculation unit 32 calculates a correction coefficient at the position using four points surrounding the position estimated as the touch position among the 25 points described above.

Since the number of points in one sensor area is larger than that in the first embodiment (9 points), the correction coefficient can be obtained using four points closer to the estimated position as the touch position. Therefore, the calculation accuracy of the correction coefficient can be improved. Thereby, since the dispersion | variation in the difference of a threshold value and an output signal can be made smaller, the determination precision of a touch and non-touch can be improved more.

[Embodiment 2]
FIG. 11 shows a schematic configuration of a touch panel unit 50 according to Embodiment 2 of the present invention. The configuration of the second embodiment is different from the configuration of the first embodiment described above in that the output signal of the Y-direction electrode 21 is corrected. In the following, the same components as those in the first embodiment will be denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.

As shown in FIG. 11, the controller 51 includes a touch position estimation unit 31, a correction coefficient calculation unit 32, a storage unit 33, an output signal correction unit 52 (correction unit), a touch determination unit 35, and a coordinate output unit 36. Each configuration of the touch position estimation unit 31, the correction coefficient calculation unit 32, the storage unit 33, the touch determination unit 35, and the coordinate output unit 36 is the same as the configuration of the above-described first embodiment, and thus description thereof is omitted.

The output signal correction unit 52 divides the correction coefficient calculated by the correction coefficient calculation unit 32 with respect to the output signal (sensor signal) of the Y-direction electrode 21 at the position estimated as the touch position, thereby obtaining the output signal. to correct. That is, in the present embodiment, unlike the above-described first embodiment, the variation of the output signal with respect to the threshold value is reduced by correcting the output signal. As in the first embodiment, the correction coefficient is a coefficient for correcting an output signal that differs depending on the touch position so that variations in the output signal with respect to a threshold value for determining whether touch or non-touch is reduced.

Although not particularly illustrated, in the case of this embodiment, if the output signal is corrected using the correction coefficient in step S7 in the flow shown in FIG. 9 of the first embodiment, the touch determination is performed as in the first embodiment. It can be performed.

(Effect of Embodiment 2)
In this embodiment, the output signal correction unit 52 corrects the output signal output from the Y-direction electrode 21 of the touch panel 2, thereby reducing variations in the output signal with respect to the threshold value. Thereby, it can prevent that the determination precision of a touch and a non-touch falls by a touch position.

(Other embodiments)
While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

In the first embodiment, the Y-

direction electrode pads

21a and 21c and the

X-direction electrode pads

22a and 22b are formed in a substantially rectangular shape or a substantially triangular shape. However, the Y-direction electrode pad and the X-direction electrode pad may be formed in other shapes such as a polygon or a circle. The structure of the touch panel 2 is not limited to the structure disclosed in the first embodiment, and may be another structure.

In the first embodiment, the storage unit 33 stores 9 or 25 reference values in one sensor area of the touch panel 2. However, the number of positions stored in the storage unit 33 may be any number as long as it is 9 or more. Further, instead of storing the reference value, an expression representing the distribution of the reference value in one sensor area may be stored.

In the first embodiment, the correction coefficient of the position is calculated using four reference values surrounding the position estimated as the touch position. However, any number of reference values may be used as long as the correction coefficient for the position estimated as the touch position can be calculated.

In the first embodiment, linear interpolation is used when obtaining the correction coefficient. However, the present invention is not limited to this, and other interpolation methods such as a Lagrange interpolation method may be used.

In each of the above embodiments, the output signal is input from the touch panel 2 to the

controllers

3 and 51. However, the present invention is not limited to this. Processing may be performed. Various processes performed by the

controllers

3 and 51 may be performed by a plurality of control devices.

In each of the embodiments described above, the X-direction electrode 22 is a side to which a voltage is applied, and the Y-direction electrode 21 is a side that outputs a current value. However, the controller 3 may read the current output from the X direction electrode 22 by applying a voltage to the Y direction electrode 21.

The touch panel according to the present invention can be used as a touch panel touched with a pen.

Claims

A touch panel having a substrate, a first electrode formed on the substrate so as to extend in one direction, and a second electrode formed on the substrate so as to extend in a direction intersecting the first electrode;
A touch detection unit that detects touch and non-touch by comparing a sensor signal output from the first electrode or the second electrode with a threshold value;
The touch detection unit
When a plurality of reference positions on the substrate are touched, a signal output from the first electrode or the second electrode, and when one reference position of the plurality of reference positions is touched, the first A storage unit in which a reference value that is a ratio to a signal output from one electrode or the second electrode is stored in a readable manner;
A touch position estimation unit that estimates a touch position on the substrate based on the sensor signal;
A correction unit that corrects one of the sensor signal and the threshold value at the touch position using the reference value;
A touch panel unit, comprising: a touch determination unit that compares the value corrected by the correction unit with the uncorrected value of the sensor signal and the threshold value, and determines touch and non-touch.
A correction coefficient calculation unit for obtaining a correction coefficient at the touch position using the reference value;
The touch panel unit according to claim 1, wherein the correction unit corrects one of the sensor signal and the threshold value at the touch position using the correction coefficient.
The touch panel unit according to claim 2, wherein the correction coefficient calculation unit obtains the correction coefficient at the touch position using reference values at a plurality of reference positions surrounding the touch position.
The correction coefficient calculation unit uses a reference value of two reference positions arranged in one direction and a reference value of two reference positions arranged in the other direction among the four reference positions surrounding the touch position, The touch panel unit according to claim 3, wherein the correction coefficient at the touch position is obtained.
The touch panel unit according to any one of claims 2 to 4, wherein the correction coefficient calculation unit obtains the correction coefficient of the touch position by linear interpolation using reference values at a plurality of reference positions.
The correction unit corrects the threshold using the correction coefficient at the touch position,
The touch panel unit according to any one of claims 2 to 5, wherein the touch determination unit compares the threshold value after correction with the sensor signal to determine whether touch or non-touch.
Based on the sensor signal output from the touch panel arranged so that the first electrode extending in one direction and the second electrode extending in the other direction intersect on the substrate, the touch position of the touch panel is estimated,
A signal output from the touch panel when each of a plurality of reference positions on the touch panel is touched, and a signal output from the touch panel when one of the plurality of reference positions is touched. Using the reference value that is a ratio, correct one of the sensor signal at the touch position and a threshold value for determining touch and non-touch,
A touch determination method for a touch panel, wherein touch and non-touch are determined by comparing the corrected value with an uncorrected value of the sensor signal and the threshold value.