This application claims the benefit of priority to Japanese Patent Application Number 2020-180158 filed on Oct. 28, 2020. The entire contents of the above-identified application are hereby incorporated by reference.
The present disclosure relates to a touch panel system that detects the position of an indicator, such as a finger or a touch pen, and the magnitude of pressure applied by the indicator, and to a display device including the touch panel system.
In recent years, mutual-capacitive touch panels have been in wide use. A mutual-capacitive touch panel includes a drive electrode to which a drive signal is input and a detection electrode. In this touch panel, an indicator is capacitively coupled to each of the drive electrode and the detection electrode, and thus electrostatic capacitance between both the electrodes decreases, and a signal of the detection electrode changes. The position of the indicator is detected on the basis of a change in the signal of the detection electrode.
For example, JP 2014-179035 A proposes a touch panel system that reduces the influence of noise to detect the position of an indicator with high accuracy by integrating (cumulatively adding) a difference value between signals obtained from two types of detection electrodes, namely, a main sensor and a sub-sensor.
In a touch panel having a configuration capable of detecting the position of an indicator and the magnitude of pressure applied by the indicator, electrodes for detecting these may be provided separately. Even when a controller of the related art as disclosed in JP 2014-179035 A is combined with such a touch panel, the position and pressure applied by the indicator cannot be detected simultaneously.
Thus, the present disclosure provides a touch panel system capable of simultaneously detecting the position of an indicator and the magnitude of pressure applied by the indicator, and a display device including the touch panel system.
In order to solve the above-described problems, a touch panel system according to an embodiment of the present disclosure includes a touch panel including a drive electrode, a position detection electrode, and a pressure detection electrode, and a controller configured to impart a drive signal to the drive electrode and acquire signal values from each of the position detection electrode and the pressure detection electrode, and the controller detects a position of an indicator on the basis of the signal values obtained from the position detection electrode and calculates a magnitude of pressure applied by the indicator on the basis of signal values in a pressure detection range corresponding to the detected position of the indicator among the signal values obtained from the pressure detection electrode.
In the touch panel system having the configuration described above, the controller detects the position of the indicator and calculates a pressure value on the basis of the signal values in the pressure detection range corresponding to the position. Thus, the touch panel system can simultaneously detect the position of the indicator and the magnitude of pressure applied by the indicator.
The disclosure will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals and signs, and the description thereof will not be repeated. Note that, for ease of description, in the drawings referred to below, configurations may be simplified or schematically illustrated, and some components may be omitted. Further, dimensional ratios between components illustrated in the drawings are not necessarily indicative of actual dimensional ratios. Further, in the drawings referred to below, various electrodes are displayed with hatching in order to facilitate the identification of the various electrodes.
First, a configuration of a touch panel system S will be described with reference to the drawings.
The touch panel 1 includes a drive electrode, a position detection electrode, and a pressure detection electrode, as will be described below. The controller 2 imparts a drive signal to the drive electrode to obtain a signal from each of the position detection electrode and the pressure detection electrode and generate output data including the position of an indicator and the magnitude of pressure applied by the indicator. For example, the output data is used for the control of an image displayed on a display device, and the like in a control unit included in the display device including the touch panel system S.
Next, a configuration of the touch panel 1 will be described with reference to the drawings.
As illustrated in
The first substrate 10 and the second substrate 20 are disposed such that a first surface 101 of the first substrate 10 and a second surface 201 of the second substrate 20 face each other. The drive electrode 11 is an electrode to which a drive signal is imparted and is formed on the first surface 101. The floating island electrode 12 is in a floating state and is formed on the first surface 101.
The position detection electrode 21 is an electrode for detecting the position of an indicator and is formed on the second surface 201. The pressure detection electrode 22 is an electrode for detecting the magnitude of pressure applied by the indicator and is formed on the second surface 201. The shield electrode 23 is provided with a potential equal to a ground potential or a potential provided to the position detection electrode 21 or the pressure detection electrode 22 or is in a floating state, and is formed on the second surface 201.
As illustrated in
As illustrated in
In addition, as illustrated in
When the second substrate 20 is viewed from the first substrate 10 in a plan view (hereinafter, simply referred to as a “plan view”), the drive electrode 11 covers at least a portion of the pressure detection electrode 22. Note that in the touch panel 1 illustrated in
Next, operations of the touch panel 1 will be described with reference to the drawings. In
Additionally, as illustrated in
When the first substrate 10 is pressed by the indicator F, the distance between the drive electrode 11 and the position detection electrode 21 decreases. However, since the drive electrode 11 is closer to the shield electrode 23 than to the position detection electrode 21, the drive electrode 11 is likely to be capacitively coupled to the shield electrode 23. Thus, electrostatic capacitance between the drive electrode 11 and the position detection electrode 21 is less likely to increase, and the decrease in electrostatic capacitance between the drive electrode 11 and the position detection electrode 21 due to the indicator F is less likely to be canceled out.
In addition, since the indicator F is closer to the shield electrode 23 than to the pressure detection electrode 22 on a path from the indicator F to the pressure detection electrode 22, the indicator F is likely to be capacitively coupled to the shield electrode 23. Thus, the indicator F is inhibited from being capacitively coupled to each of the drive electrode 11 and the pressure detection electrode 22, and this inhibits electrostatic capacitance between both the electrodes from fluctuating.
The touch panel system S is included in, for example, a display device.
Next, a method of detecting the position of the indicator F and the magnitude of pressure applied by the indicator F, by the controller 2 will be described with reference to the drawings.
As illustrated in
Here, the input data ID will be described with reference to the drawings. The input data ID illustrated in
The input data ID is data that is a combination of signal values obtained from the position detection electrodes 21 and the pressure detection electrodes 22 in different regions of a single two-dimensional coordinate system. The input data ID illustrated in
Hereinafter, description will be given of an example in a case where a signal value of an element equivalent to the vicinity of the center of a contact portion of the indicator F in the position detection map TM increases to a positive value, and a signal value of an element equivalent to the vicinity of the center of a contact portion of the indicator F in the pressure detection map FM increases to a positive value in a case where the surface of the touch panel 1 is pressed by the indicator F in the input data ID.
Next, the controller 2 detects a position TP of the indicator F from the position detection map TM of the input data ID (step #2). For example, the controller 2 detects an element of which the signal value is equal to or greater than a predetermined threshold and is a maximum in the position detection map TM among the elements in the position detection map TM, as the position TP of the indicator F. Note that in a case where there is no element of which the signal value is equal to or greater than the threshold value in the position detection map TM, the controller 2 may determine that the indicator F that is in contact with the touch panel 1 is not present, and output output data indicating the absence of the indicator F.
Next, the controller 2 calculates a specific position of the indicator F (step #3). A method of calculating the specific position by the controller 2 will be described with reference to
As illustrated in
The controller 2 calculates a signal value C(X, Y) by cumulatively adding signal values D(X, Y) in the position detection range TR in the Y direction. Specifically, the controller 2 calculates the signal value C(X, Y) from C(X, Y=C(X, Y−1)+D(X, Y). However, when the signal value C(X, Y is calculated, the controller 2 sets C(X, Y)=D(X, Y) for elements at an upper end in the position detection range TR for which C(X, Y−1) cannot be calculated.
For the calculated signal value C(X, Y), the controller 2 calculates the position of the center of gravity on the basis of the magnitude of the signal value and coordinates (X, Y), and sets the position of the center of gravity as a specific position of the indicator F. When the specific position of the indicator F is calculated in this way, the position of the indicator F which is present between the coordinates (X, Y) can be detected, and thus a resolution for detecting the position of the indicator F can be improved.
Next, the controller 2 sets a pressure detection range FR in the pressure detection map FM of the input data ID (step #4). As illustrated in
Next, the controller 2 calculates a pressure value which is the magnitude of pressure applied by the indicator F, on the basis of signal values in the pressure detection range FR (step #5). For example, the controller 2 calculates the pressure value by adding up absolute values of the signal values in the pressure detection range FR. Note that, in a method of calculating a pressure value including a method of setting the pressure detection range FR, it is preferable to set a pressure value to be a value proportional to a pressing force, for example, when the indicator F, which is a fixed contact area, is pressed against the touch panel 1 while changing the pressing force.
Finally, the controller 2 generates and outputs output data including the specific position and the pressure value of the indicator F (step #6).
As described above, in the touch panel system S, the controller 2 detects the position TP of the indicator F, and calculates a pressure value on the basis of the signal value of the pressure detection range FR corresponding to the position TP (the position FP). Thus, the touch panel system S can simultaneously detect the position of the indicator F and the magnitude of pressure applied by the indicator F.
Further, in the touch panel system S, the input data ID is composed of a combination of signal values obtained from each of the position detection electrode 21 and the pressure detection electrode 22 in different regions of a single two-dimensional coordinate system. Thus, it is possible to obtain the controller 2 that is applicable to the touch panel system S by simply changing the design of the controller that detects only the position of the indicator F of the related art.
Next, a second embodiment will be described. The second embodiment differs from the first embodiment in terms of the method of calculating a pressure value by the controller 2. Thus, a method of calculating a pressure value in the second embodiment will be described below.
Next, the controller 2 amplifies the tentative value to calculate a pressure value (step #52). A method of amplifying the tentative value is arbitrary. For example, the controller 2 may multiply the tentative value by an amplification factor and then add or subtract an offset value to or from the value to calculate a pressure value.
As described above, in the touch panel system S, the controller 2 amplifies a tentative value to calculate a pressure value. Thus, the touch panel system S can accurately calculate the pressure value corresponding to the magnitude of pressure applied by the indicator F.
Next, a third embodiment will be described. Also, in the third embodiment, a pressure value is calculated by amplifying a tentative value in the same manner as in the second embodiment, but the amplification method thereof is unique. Thus, the method of amplifying a tentative value according to the third embodiment will be described below.
As a contact range of the indicator F increases, a force of pressure applied by the indicator becomes dispersed over a larger range, which may result in a case where a pressure value to be calculated becomes smaller. In the touch panel system S according to the third embodiment, the controller 2 amplifies a tentative value to calculate a pressure value as described above, thereby preventing the pressure value from decreasing in a case where a contact range of the indicator F increases.
As described above, in the touch panel system S, the controller 2 amplifies a tentative value more greatly as the number of signal values C(X, Y) equal to or greater than the first threshold value increases. Thus, even when a contact range of the indicator F increases, the touch panel system S can calculate a pressure value with high accuracy.
Next, a fourth embodiment will be described. Also, in the fourth embodiment a pressure value is calculated by amplifying a tentative value in the same manner as in the second and third embodiments, but the fourth embodiment differs from the third embodiment in terms of the amplification method. Thus, a method of amplifying a tentative value according to the fourth embodiment will be described below.
Similar to the second embodiment, also in the touch panel system S according to the third embodiment, the controller 2 calculates a pressure value by amplifying a tentative value as described above, thereby preventing the pressure value from decreasing in a case where a contact range of the indicator F increases.
As described above, in the touch panel system S, the controller 2 amplifies a tentative value more greatly as the number of signal values C(X, Y) equal to or greater than the first threshold value increases. Thus, even when a contact range of the indicator F increases, the touch panel system S can calculate a pressure value with high accuracy.
Further, in the third embodiment, the magnitude of amplification is determined in accordance with the sum of signal values C(X, Y), and thus it is possible to prevent the magnitude of amplification from varying due to a slight difference in one signal value C(X, Y), unlike in a case where the magnitude of amplification is determined in accordance with the number of signal values C(X, Y). Thus, a pressure value can be calculated with higher accuracy.
Modifications and the Like
The above-described embodiments are merely examples for carrying out the present disclosure. Accordingly, the present disclosure is not limited to the embodiments described above and can be implemented by modifying the embodiments described above as appropriate without departing from the scope of the present disclosure.
For example, in the touch panel systems S in the first to third embodiments described above, a case where the controller 2 detects the position TP of the indicator F in step #2 and then calculates a specific position of the indicator in step #3 has been exemplified. However, the controller 2 may set coordinates of the position TP of the indicator F detected in step #2 as a specific position of the indicator F as is without performing step #3.
Further, in the touch panel systems S in the first to third embodiments described above, a case where the controller 2 sets the pressure detection range FR on the basis of the position TP of the indicator F detected in step #2 has been exemplified. However, the controller 2 may set the pressure detection range FR on the basis of the specific position of the indicator F calculated in step #3.
Further, in the touch panel systems S in the third and fourth embodiments described above, a case where the controller 2 amplifies a tentative value using an amplification method based on the signal values C(X, Y) has been exemplified, but a tentative value may be amplified by an amplification method based on signal values D(X, Y) before conversion to the signal values C(X, Y) illustrated in
Further, in the touch panel systems S in the first to third embodiments described above, the floating island electrode 12 and the shield electrode 23 need not be provided. In addition, each of the drive electrode 11, the floating island electrode 12, the position detection electrode 21, and the pressure detection electrode 22 may be formed in a pattern other than a diamond pattern. Additionally, some or all of the position detection electrode 21, the pressure detection electrode 22, and the shield electrode 23 may be formed of a mesh metal (thin metal wires having a mesh shape).
In addition, the touch panel system and the display device described above can be described as follows.
A touch panel system includes a touch panel including a drive electrode, a position detection electrode, and a pressure detection electrode, and a controller configured to impart a drive signal to the drive electrode and acquire signal values from each of the position detection electrode and the pressure detection electrode, and the controller detects a position of an indicator on the basis of the signal values obtained from the position detection electrode and calculates a magnitude of pressure applied by the indicator on the basis of signal values in a pressure detection range corresponding to the detected position of the indicator among the signal values obtained from the pressure detection electrode (first configuration). According to this configuration, the controller detects the position of the indicator and calculates a pressure value on the basis of the signal values in the pressure detection range corresponding to the position. Accordingly, the touch panel system can simultaneously detect the position of the indicator and the magnitude of pressure applied by the indicator.
In the first configuration, the controller may calculate the position of the indicator and the magnitude of pressure applied by the indicator on the basis of input data that is a combination of the signal values obtained from each of the position detection electrode and the pressure detection electrode in different regions of a single two-dimensional coordinate system (second configuration). Furthermore, in the second configuration, the controller may detect the position of the indicator from a position detection map constituted by the signal values obtained from the position detection electrode, and may set the pressure detection range which is in a pressure detection map constituted by the signal values obtained from the pressure detection electrode and includes a position corresponding to the position of the indicator (third configuration). According to this configuration, it is possible to obtain a controller 2 that is applicable to a touch panel system by simply changing the design of a controller that detects only the position of an indicator of the related art.
In any one of the first to third configurations, the controller may amplify a tentative value on the basis of the signal values in the pressure detection range to calculate the magnitude of pressure applied by the indicator (fourth configuration). According to this configuration, a pressure value corresponding to the magnitude of pressure applied by the indicator can be calculated with high accuracy.
In the fourth configuration, the controller may calculate the magnitude of pressure of the indicator by amplifying the tentative value more greatly as a contact range of the indicator becomes wider (fifth configuration). According to this configuration, it is possible to prevent a pressure value from decreasing in a case where the contact range of the indicator increases.
In the fifth configuration, the controller may calculate the magnitude of pressure applied by the indicator by greatly amplifying the tentative value as the number of signal values indicating a contact of the indicator increases within a position detection range including the detected position of the indicator (sixth configuration). According to this configuration, even when the contact range of the indicator has become larger, the magnitude of pressure applied by the indicator can be calculated with high accuracy.
Alternatively, in the fifth configuration, the controller may amplify the tentative value more greatly as the sum of the signal values indicating a contact of the indicator becomes larger within the position detection range including the detected position of the indicator (seventh configuration). According to this configuration, it is possible to prevent the magnitude of amplification from varying due to a slight difference in one signal value, and thus the magnitude of pressure applied by the indicator can be accurately calculated.
Another embodiment of the present disclosure is a display device that includes the touch panel system according to any one of the first to seventh configurations and a display unit configured to display an image, the display device being configured such that the touch panel is disposed on a display surface on which the display unit displays an image (eighth configuration).
While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
Number | Date | Country | Kind |
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2020-180158 | Oct 2020 | JP | national |