JP2014179035A - Touch panel device and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel device capable of determining whether there is external noise.SOLUTION: A touch panel device (1) includes: a noise presence/absence determination part (131) which determines whether there is noise on the same sense line in a sense difference signal value map; and a noise removal determination part (133) which determines whether there is noise on the same sense line in a drive difference signal value map obtained by differentiating a sense signal in a drive line direction.

Description

  The present invention relates to a touch panel device, and more particularly to a touch panel device in which external noise is generated on a touch panel.

  In recent years, touch panel devices have been used as user interfaces for portable communication devices such as smartphones and vending machines such as automatic ticket vending machines. That is, the touch panel device is widely used not only indoors but also outdoors.

  In general, a touch sensor panel (touch panel) superimposed on a display unit disposed on the top or front of an electronic device is not only affected by noise such as a clock generated in the electronic device but also by various external noises. Cheap. These noises may be mixed into a signal indicating the touch position on the touch panel, and may reduce the sensitivity and accuracy of detecting the touch-operated position.

  For this reason, a method has been conventionally proposed in which extraneous noise that affects the performance of the touch panel is removed from the touch signal to acquire a true touch signal.

  Patent Document 1 discloses a technique for canceling noise generated on a touch panel by taking a difference between a sense line and a sub-sense line. According to this configuration, noise generated in the touch panel is detected using the sub sense line, and the noise component mixed in the signal on the sense line is removed by taking the difference between the sense line and the sub sense line. . Thereby, it can avoid that the detection precision of a touch position falls by the influence by the noise mixed in the touch signal.

  Patent Document 2 discloses a touch panel device that detects a variation level of a signal level (signal intensity) output from a reception unit and sets a sample timing of a sample hold unit so that sampling is performed at a timing at which the variation level is reduced. Is disclosed. This patent document 2 further discloses a method of setting the frequency of the drive signal applied from the transmission unit to the drive line so that the variation level of the signal level output from the reception unit is reduced. As a result, variations in the signal level output from the receiving unit are suppressed, and a stable output signal that is not affected by external noise can be obtained. As a result, it is possible to avoid a decrease in touch position detection accuracy due to the influence of external noise.

  Patent Document 3 discloses a touch panel device that switches the frequency of a drive signal to another frequency when the frequency of external noise substantially matches any one frequency of the drive signal. Accordingly, the influence of the external noise is suppressed by making the frequency of the voltage signal that matches the frequency of the drive signal of the drive line different from the frequency of the external noise.

JP 2012-168919 A (published September 6, 2012) JP 2011-128858 A (released June 30, 2011) JP 2011-128857 A (released June 30, 2011)

  However, the conventional technology as described above cannot remove noise generated along the sense line, particularly noise having a relatively low frequency. There is a problem that the touch position may not be accurately detected due to the influence of noise remaining without being removed.

  Specifically, according to the method disclosed in Patent Document 1, random noise generated on the touch panel can be removed by using a difference from the sub sense line, but on the sense line corresponding to the touch position. It is difficult to remove external noise generated in a distributed manner.

  In addition, when the noise removal method disclosed in Patent Document 2 or Patent Document 3 is used, the system acquires the presence and frequency of the external noise causing the variation in the signal level output from the receiving unit. Is required. However, it is generally difficult to detect noise mixed in a signal and analyze its frequency, and there are only a limited number of scenes where such a noise removal method can be applied.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a touch panel device that determines the presence or absence of external noise generated on the touch panel.

  In order to solve the above problems, a touch panel device according to one embodiment of the present invention includes a plurality of first signal lines extending substantially parallel to a first direction and a second direction orthogonal to the first direction. A signal intensity of a first signal value corresponding to a capacitance value formed at each intersection of the first signal line and the second signal line. A touch position detecting unit that detects a touch position received by a user based on a signal strength of a touch signal corresponding to the capacitance value, An integration processing unit that integrates the first signal value along the second signal line to generate a second signal value; and a third signal that differentiates the second signal value along the first signal line. A differential processing unit for generating a value, and a predetermined first threshold When the third signal value indicating the signal intensity exceeding the first predetermined number or more exists on the same first signal line, it is determined that the touch signal is mixed with external noise that prevents the touch position from being detected. And a noise removal necessity determination unit.

  The touch panel device control method according to one embodiment of the present invention includes a plurality of first signal lines extending substantially parallel to the first direction and a second direction orthogonal to the first direction. A touch panel that has a plurality of extending second signal lines and acquires the signal intensity of the first signal value corresponding to the capacitance value formed at each intersection of the first signal line and the second signal line. A touch position detection unit that detects a touch position that has been touched by a user based on a signal intensity of a touch signal corresponding to the capacitance value, wherein the touch panel device includes the first signal value. Is integrated along the second signal line to generate a second signal value, and the second signal value is differentiated along the first signal line to generate a third signal value. Differential processing step and predetermined first threshold When the third signal value indicating the signal intensity exceeding the first predetermined number or more exists on the same first signal line, it is determined that the touch signal is mixed with external noise that prevents the touch position from being detected. And a noise removal necessity determination step.

  According to one aspect of the present invention, in a touch panel device that detects a position where a user performs a touch operation, the presence or absence of external noise that electromagnetic noise received by a human body or the like is mixed into a touch signal via an indicator is determined. There is an effect that can be.

It is the schematic explaining the structural example of the display apparatus of the touchscreen apparatus which concerns on Embodiment 1 of this invention. It is the schematic which shows a part of basic composition of the touchscreen apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the basic process of the touchscreen apparatus of FIG. In the touch panel device according to Embodiment 1 of the present invention, (a) a sense difference signal value map corresponding to a touch signal and (b) a sense difference signal value map are three-dimensionally represented. In the sense difference signal value map of FIG. 4, (a) a sense signal value map obtained by cumulatively adding sense difference signal values in the sense line direction, and (b) a three-dimensional representation of the sense signal value map. is there. In the sense signal value map of FIG. 5, (a) a drive difference signal value map obtained as a result of obtaining a difference between sense signal values in the drive line direction, and (b) a drive difference signal value map obtained in three dimensions. FIG. In the touch panel device according to Embodiment 2 of the present invention, (a) a sense difference signal value map corresponding to a touch signal and (b) a sense difference signal value map are three-dimensionally represented. In the sense difference signal value map of FIG. 7, (a) a sense signal value map obtained by cumulatively adding sense difference signal values in the sense line direction, and (b) a three-dimensional representation of the sense signal value map. is there. In the sense signal value map of FIG. 8, (a) a drive difference signal value map obtained as a result of obtaining a difference between sense signal values in the drive line direction, and (b) a drive difference signal value map obtained in three dimensions. FIG. In the touch panel device according to Embodiment 2 of the present invention, (a) a sense difference signal value map corresponding to a touch signal and (b) a sense difference signal value map are three-dimensionally represented. In the sense difference signal value map of FIG. 10, (a) a sense signal value map obtained by cumulatively adding sense difference signal values in the sense line direction, and (b) a three-dimensional representation of the sense signal value map. is there. In the sense signal value map of FIG. 11, (a) a drive difference signal value map obtained as a result of obtaining a difference between sense signal values in the drive line direction, and (b) a drive difference signal value map obtained in three dimensions. FIG. In the touch panel device according to Embodiment 2 of the present invention, (a) a sense difference signal value map corresponding to a touch signal and (b) a sense difference signal value map are three-dimensionally represented. In the sense difference signal value map of FIG. 13, (a) a sense signal value map obtained by cumulatively adding sense difference signal values in the sense line direction, and (b) a three-dimensional representation of the sense signal value map. is there. In the sense signal value map of FIG. 14, (a) a drive difference signal value map obtained as a result of obtaining a difference of sense signal values in the drive line direction, and (b) a obtained drive difference signal value map in a three-dimensional manner. FIG. In the touch panel device according to Embodiment 2 of the present invention, (a) a sense difference signal value map corresponding to a touch signal and (b) a sense difference signal value map are three-dimensionally represented. In the sense difference signal value map of FIG. 16, (a) a sense signal value map obtained by cumulatively adding sense difference signal values in the sense line direction, and (b) a three-dimensional representation of the sense signal value map. is there. In the sense signal value map of FIG. 17, (a) a drive difference signal value map obtained as a result of obtaining a difference between sense signal values in the drive line direction, and (b) a obtained drive difference signal value map are three-dimensionally represented. FIG. It is a figure which shows the sense line in which the area | region where touch operation was performed, and an external noise mix. It is a figure which illustrates the case where the external noise mixes on the sense line which detected the finger touch signal in the touch panel which detected the sense signal resulting from touch operation.

Embodiment 1
(Configuration of touch panel device 1)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, the side used by the user (operating side) will be described as the front surface (or upward).

  First, a basic configuration example of the display device 2 of the touch panel device 1 according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 2 is a schematic diagram showing a part of the basic configuration of the touch panel device 1, and shows only the configuration up to the decoding processing unit 12. A configuration example of the touch panel device 1 including a configuration for processing a signal output from the decoding processing unit 12 will be described later with reference to FIG.

  The display device 2 includes a display surface (display unit). On the display surface, various icons for accepting user operations / instructions and activating application software (applications), images and characters according to user operations, and the like are displayed. The display device 2 can be composed of, for example, a liquid crystal display (LCD), a plasma display, an organic EL, a field emission display (FED), or the like. These thin displays are used in electronic devices used for a wide range of applications, and the highly versatile touch panel device 1 is configured. The display device 2 may have any configuration and is not particularly limited.

  The touch panel 3 receives various instructions that are input when the user performs a touch operation on the surface of the touch panel 3 using a finger or a pen-type indicator. The touch panel 3 is laminated on the front surface (upper part) of the display device 2 so as to substantially cover the display surface of the display device 2.

  The touch panel 3 includes two types of sensors (main sensor 31 and sub sensor 32) provided on the same surface (in the same surface). The main sensor 31 and the sub sensor 32 are provided adjacent to each other. In FIG. 2, for the sake of simplicity, one sense line 33 is shown for the main sensor 31 and one sub sense line 34 is shown for the sub sensor 32, but the main sensor 31 is provided. The number of sense lines 33 and the number of sub sense lines 34 included in the sub sensor 32 may be arbitrary.

  In the present embodiment, a capacitive touch panel 3 including the main sensor 31 and the sub sensor 32 will be described as an example. The capacitive touch panel 3 has high transmittance and durability, and can be suitably used for the touch panel device of the first embodiment. However, the method of the touch panel 3 is not limited to this. Examples of other methods of the touch panel 3 that can be used for the touch panel device 1 include a resistance film method, an electromagnetic induction method, an ultrasonic surface acoustic wave method, and an infrared scanning method.

  The main sensor (main sensor unit) 31 is provided in a touch-operated area (touch area) on the touch panel 3 and detects a touch operation by the user. The touch operation may include a double click operation, a slide operation, a single click operation, a drag operation, and various other gesture operations. The main sensor 31 includes one or more arbitrary number of sense lines 33 made of linear electrodes. One end of the sense line 33 is connected to the sense difference signal detection unit 11. As a result, the signal detected by the main sensor 31 is output to the sense difference signal detection unit 11 via the sense line 33. That is, a signal corresponding to the touch operation detected by the main sensor 31 is output to the sense difference signal detection unit 11.

  The sub sensor (sub sensor unit) 32 detects a noise component reflected on the touch panel 3. The sub sensor 32 is provided in a region (non-touch region) on the touch panel 3 where a touch operation is not performed. For this reason, the sub sensor 32 detects various noises generated on the touch panel 3 regardless of the touch operation by the user. Thus, unlike the main sensor 31, the sub sensor 32 does not detect a signal corresponding to the touch operation. That is, the sub sensor 32 detects external noise generated on the touch panel regardless of the touch operation by the user.

  The sub sensor 32 includes one or more arbitrary number of sub sense lines 34 each including a linear electrode. One sub-sense line 34 is provided in the vicinity of each sense line, one for each sense line 33 so as to be substantially parallel (a state extending in the same direction as the sense line 33). One end of the sub sense line 34 is connected to the sense difference signal detection unit 11. As a result, the signal detected by the sub sensor 32 is output to the sense difference signal detection unit 11 via the sub sense line 34. That is, a signal corresponding to the external noise detected by the sub sensor 32 is output to the sense difference signal detection unit 11.

  It is desirable that the main sensor 31 and the sub sensor 32 be provided close to each other. In other words, the sense line 33 and the sub sense line 34 are provided extending in substantially the same direction (substantially parallel to each other). Is preferred. However, the arrangement of the main sensor 31 and the sub sensor 32 is not particularly limited. As described later, a signal derived from external noise from the sub sensor 32 is subtracted from a signal including a touch signal from the main sensor 31. Thus, any configuration may be used as long as the external noise mixed in the touch signal from the main sensor 31 can be canceled.

  On the other hand, the touch panel 3 includes a drive line 35 that intersects the sense line 33 and the sub-sense line 34 so as to be substantially orthogonal. The drive line 35 is composed of a linear electrode. Capacitance is formed at the intersection between the sense line 33 and the drive line 35 and at the intersection between the sub-sense line 34 and the drive line 35. The drive line 35 is connected to the drive line driving unit 10, and a potential is applied to the drive line 35 at a constant cycle when the touch panel device 1 is activated. The drive line driving unit 10 will be described in detail later with reference to FIG.

  Each of the sense line 33, the sub-sense line 34, and the drive line 35 may be made of a transparent wiring material such as ITO (Indium Tin Oxide) or a metal mesh. It can be said that the sense line 33, the sub sense line 34, and the drive line 35 are sensor electrodes in the touch panel 3.

  The drive line 35 can be provided on a transparent substrate or a transparent film (not shown). Further, the drive line 35 is covered with an insulator (not shown). On this insulator, a sense line 33 and a sub-sense line 34 are provided. As described above, the sense line 33 or the sub sense line 34 and the drive line 35 are insulated from each other through the insulator and capacitively coupled. The sense line 33 and the sub sense line 34 are covered with a protective layer (not shown). That is, the touch panel 3 is arranged on the foremost side.

  The sense difference signal detection unit 11 has an input terminal for receiving a signal output from the main sensor 31 (input terminal for main sensor output) and an input terminal for receiving a signal output from the sub sensor 32 ( Sub-sensor output input terminal). The sense difference signal detection unit 11 calculates a sense difference signal obtained by subtracting the signal input to the sub sensor output input terminal from the signal input to the main sensor output input terminal. The sense difference signal calculated by the sense difference signal detection unit 11 is output to the decoding processing unit 12. The signal input to the sense difference signal detection unit 11 may be a digital signal or an analog signal. That is, the input signal to the sense difference signal detection unit 11 may be a signal corresponding to the configuration of the sense difference signal detection unit 11.

  Next, an outline of a basic configuration of the touch panel device 1 according to the first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the touch panel device 1 includes a display device 2, a touch panel 3, a drive line driving unit 10, a sense difference signal detecting unit 11, a decoding processing unit 12, a noise determining unit 13, a touch position detecting unit 14, and noise reduction. A processing unit 15, a touch panel control unit 16, and a signal distribution data storage unit 17 are provided. In FIG. 1 and FIG. 2, in order to avoid duplication of explanation, the same number is assigned to the same member, and the explanation is appropriately omitted. Further, the sub sense line 34 is not shown in FIG. 1 for the sake of simplicity. In the following description, the sense line S and the drive line D are respectively described to describe the intersection of the sense line 33 and the drive line 35 corresponding to the signal value acquired by the touch panel 3.

  As shown in FIG. 1, the touch panel 3 includes a plurality (m) of substantially parallel drive lines D (drive lines 35 in FIG. 2) provided along the display surface, and drive lines provided along the display surface. And a plurality (n) of substantially parallel sense lines S (sense lines 33 in FIG. 2) that intersect (three-dimensionally intersect). Capacitance is formed at the intersection of the drive line D and the sense line S. The drive line D and the sense line S are wired to the display device 2 (a panel body constituting a part of the display surface). Although FIG. 1 (and FIG. 2) shows a case where the drive line D and the sense line S intersect substantially vertically, they may intersect at an angle other than perpendicular. In addition, FIG. 1 (and FIG. 2) shows an example in which the display device 2 is formed in a flat shape, but the display device 2 is not limited to a flat surface, and may be a cylindrical shape, a cone shape, or the like. It can be configured in three dimensions. The number or arrangement of drive lines D and sense lines S is not limited to that shown in FIGS. 1 and 2, and any number or arrangement can be selected according to the shape and application of the touch panel device.

The drive line driving unit 10 is connected to the drive line D, and drives the drive line D when the touch panel device 1 is activated, thereby causing the sense line S that intersects the drive line D to generate a status signal. The state signal is a signal indicating the state of the touch operation on the intersection of the drive line D and the sense line S on the touch panel 3 and the vicinity of the intersection (detection region P, not shown). Therefore, the detection region P exists at each intersection of the sense line S and the drive line D and in the vicinity of each intersection. In the following, the intersection between the sense line S _x and the drive line D _y and the detection region existing in the vicinity of the intersection are denoted as P (S _x D _y ). X and y are integers that satisfy 0 ≦ x ≦ n−1 and 0 ≦ y ≦ m−1, respectively. That is, there are n sense lines S and m drive lines D.

  The signal intensity (state signal value) of the state signal is a value corresponding to the capacitance between the drive line D and the sense line S, and is in contact with or close to the detection region P on the touch panel 3. It is a signal which shows whether it is. That is, the status signal is a signal indicating the presence or absence of contact or proximity to the detection region P, the separation distance between the detection region P and the indicator (including the user's finger). Note that the state signal value corresponding to the electrostatic capacitance value can be configured to increase as the indicator contacts or approaches the detection region P.

  Therefore, the sense difference signal is obtained by calculating the difference (differentiation) between the state signal detected by the sense line 33 and the signal mainly derived from noise detected by the sub sense line 34.

The decoding processing unit 12 calculates the sense signal in the touch panel 3 from the sense difference signal by integrating (adding along the drive line D) the sense difference signal output from the sense difference signal detecting unit 11 in the sense line direction. . For example, when the intensity of the sense differential signal corresponding to the detection region _{P (S} x _{D y)} and _{E (S} x _{D y),} the sense signal in the detection region _{P (S} x _{D y)} is, _{E (S} x _{D y} ) + E (S _x-1 D _y ). However, in this example, the sense signal in the detection region P (S ₀ D _y ) (corresponding to the case where x is 0) can use the intensity E (S ₀ D _y ) of the sense difference signal as it is as the sense signal. The process in which the decoding processing unit 12 generates (decodes) the sense signal from the sense difference signal will be described later with a specific example. The generated distribution data (sense signal value map) of the sense signal value (second signal value) is stored in the signal distribution data storage unit 17. The touch position detection unit 14 detects the position (coordinates) where the touch operation is performed based on the sense signal value map.

  The noise determination unit 13 determines whether or not noise is included in each sense line S in the sense difference signal based on the intensity of the sense signal corresponding to each detection region P, and is effective against the noise. Determine processing. The noise determination unit 13 includes a noise presence / absence determination unit 131, a drive direction difference processing unit 132, and a noise removal determination unit 133.

The noise presence / absence determination unit 131 determines the number of detection regions P (P (S _x D _y )) in which the intensity of the sense difference signal from the decoding processing unit 12 is equal to or greater than a predetermined threshold M (second threshold) as a sense line. Count every S. For example, the noise presence / absence determination unit 131 sets a predetermined number of detection regions P indicating a sense difference signal value (first signal value) equal to or greater than a predetermined threshold M on a certain sense line S _x (0 ≦ x ≦ n−1). If it is detected at least H (second predetermined number), it is determined that external noise is detected (exists) on the sense line _Sx . When it is determined that there is noise, the noise presence / absence determination unit 131 sends an instruction corresponding to the determination to the drive direction difference processing unit 132. The noise presence / absence determination unit 131 that has determined that there is external noise instructs the drive direction difference processing unit 132 to create distribution data (drive difference signal value map) of the drive difference signal value (third signal value). On the other hand, the noise determining unit 131, on the sense line S _x, the case of detecting less than H number is detection region P is equal to or greater than a predetermined threshold value M, external noise is not generated along the sense line S _x, Is determined. When it is determined that there is no noise, the noise presence / absence determination unit 131 sends an instruction corresponding to the determination to the touch position detection unit 14.

  The predetermined number H can be suitably determined according to the number of intersections or detection regions P included in the region corresponding to the touch position when a touch operation is performed by the user. For example, when the user performs a touch operation with his / her fingertip, the predetermined number H is set to 4 because the area where the touch operation is received is wide, and when the user performs the touch operation using a dedicated pen-type tool, The predetermined number H may be set as appropriate, such as 1 because the area to receive is small. Further, the threshold value M may be set so that, for example, a position where a touch operation performed using a pen-type tool is performed can be detected.

  When the noise presence / absence determination unit 131 determines that noise occurring on a certain sense line S is distributed (present) on the sense line S based on the distribution of sense difference signal values, drive direction difference processing The unit 132 calculates a difference (differentiation) of the sense signal value along the drive line direction according to an instruction from the noise presence / absence determination unit 131, and generates a drive difference signal.

  Here, the meaning of the word “sense line direction” means here the direction along a certain drive line D, and the meaning of the word “drive line direction” means here the direction along a certain sense line S. Means.

For example, if the sense signal value corresponding to the detection region P (S _x D _y ) is C (S _x D _y ), the drive difference signal value (drive difference signal value F (S (S)) in the detection region P (S _x D _y ) _x D _{y)) is} determined by _{C (S x D y) -C} (S x D y-1). However, in this example, the sense signal value C (S _x D ₀ ) of the detection region P (S _x D ₀ ) (corresponding to the case where y is ₀ ) can be used as it is as the drive differential signal value. The process in which the drive direction difference processing unit 132 generates (decodes) the drive difference signal from the sense signal will be described later with a specific example.

The noise removal determination unit 133 detects a detection region P (P (S _x D _y ) indicating a drive difference signal value whose intensity of the drive difference signal calculated by the drive direction difference processing unit 132 is equal to or greater than a predetermined threshold N (first threshold). )) Is counted for each sense line S. For example, the noise removal determination unit 133 sets a predetermined number G (first predetermined number) of detection regions P indicating a drive difference signal value equal to or greater than a predetermined threshold N on a certain sense line S _x (0 ≦ x ≦ n−1). ) If detected above, it is determined that the external noise exists along the sense line _Sx .

The noise removal determination unit 133 is a signal corresponding to an intersection (detection region P) indicating a drive differential signal value having a signal intensity equal to or greater than a predetermined threshold N on a certain sense line S _x (0 ≦ x ≦ n−1). Is detected as an extraneous noise along the sense line _Sx , and N signals corresponding to an intersection (detection region P) having a signal intensity equal to or greater than a predetermined threshold N are determined. If less than it is detected, it is determined that no external noise exists along the sense line _Sx . When it is determined that the external noise exists, the noise removal determination unit 133 outputs a noise reduction processing instruction to the noise reduction processing unit 15, and when it is determined that the external noise does not exist, the touch position detection unit 14 In response to this, a touch position detection instruction is output.

  Note that the predetermined number G can be suitably determined according to the number of intersections or detection regions P included in the region corresponding to the touch position when a touch operation is performed by the user. For example, when the user performs a touch operation with the fingertip, the predetermined number G is set to 4 because the area for receiving the touch operation is wide, and when the user performs the touch operation using a dedicated pen-type tool, The predetermined number G can be set as appropriate, such as 1 because the area to receive is small. Further, the threshold value N may be set so that, for example, a position where a touch operation performed using a pen-type tool is performed can be detected.

  When the touch position detection unit 14 receives a touch position detection instruction from the noise presence / absence determination unit 131 or the noise removal determination unit 133, the position where the touch operation is performed based on the distribution of the sense signal values generated by the decoding processing unit 12. (Coordinates corresponding to the intersection of the sense line S and the drive line D) are detected. Information on the detected position (touch information) is output to a control unit (not shown) of an electronic device on which the touch panel device 1 is mounted or used.

  The noise reduction processing unit 15 sends a control signal for performing noise reduction processing to the touch panel control unit 16 in response to an instruction output when the noise removal determination unit 133 determines that external noise exists on the sense line S. To emit. The noise reduction process at this time may be a method such as frequency spreading or frequency shifting. For example, the technique disclosed in Patent Document 2 or Patent Document 3 can be used.

  The touch panel control unit 16 controls the drive line driving unit 10, the sense difference signal detection unit 11, and the decoding processing unit 12.

  The signal distribution data storage unit 17 is a storage unit that temporarily stores the distribution of sense difference signal values generated by the sense difference signal detection unit 11 and the distribution of sense signal values generated by the decoding processing unit 12.

(External noise mixed in sense signal corresponding to touch operation)
Here, the external noise mixed in the sense signal corresponding to the touch operation will be described with reference to FIGS. 19 and 20.

  FIG. 19 is a diagram illustrating a region where a touch operation is performed by the user and a sense line S in which external noise is mixed. When the region A is touch-operated by the user, the external noise mixed due to the touch operation can be detected on the sense line S included in the region B.

  FIG. 20 is a graph showing the intensity distribution of the sense signal when there is external noise. In the graph shown in FIG. 20, the height indicates the intensity of the sense signal. The intensity of the sense signal obtained from a certain sense line S when a drive signal is supplied to a certain drive line is plotted at the intersection of the drive line D and the sense line S.

  The central peak shown in FIG. 20 is a sense signal resulting from a touch operation by the user. When external noise exists, a small signal is detected in addition to the touched position. This small signal is a sense signal caused by external noise, and a plurality of small peaks can be detected along the sense line S where the touch operation is detected.

(Noise detection process flow of the touch panel device 1)
In the touch panel device 1, since the touch panel 3 is bonded to the front surface (user side) of the display device 2, the touch panel device 1 uses not only noise such as a clock generated by the display device 2 but also electromagnetic waves from other surroundings. It can be affected by various external noises. Such various noises are one of the causes of touch panel detection sensitivity reduction or erroneous recognition of the touch position. Below, the flow of processing in which the touch panel device 1 detects external noise will be described with reference to FIG.

  FIG. 3 is a flowchart showing basic processing of the touch panel device 1 of FIG.

  In step S1, the touch panel device 1 is activated and the touch panel 3 is driven. Specifically, when the touch panel device 1 is activated, a potential is applied from the drive line driving unit 10 to the drive line 35 at a constant cycle. When the user performs a touch operation on the touch panel 3, both the main sensor 31 and the sub sensor 32 output signals to the sense difference signal detection unit 11.

  In step S <b> 2, the sense difference signal detection unit 11 acquires a signal (state signal) corresponding to the capacitance value from the main sensor 31 and the sub sensor 32. The sense difference signal detection unit 11 calculates the difference (sense difference signal) between the state signal detected by the sense line 33 and the signal mainly derived from noise detected by the sub sense line 34, for each of the sense line S and the drive line D. Calculation is performed for the intersection (each detection region).

  Here, noise such as a clock generated by the display device 2 and other external noise are reflected on the touch panel 3. For this reason, the main sensor 31 and the sub sensor 32 detect various noise components. That is, in the output signal from the main sensor 31, a noise signal (noise component) is added to the original signal of the touch operation. On the other hand, the sub sensor 32 does not detect a touch operation. For this reason, the output signal from the sub sensor 32 includes a noise signal (noise component), but does not include a touch operation signal.

  In the touch panel device 1, the main sensor 31 and the sub sensor 32 are provided in the same plane and are provided adjacent to each other. For this reason, the noise signal value included in the output signal of the main sensor 31 and the noise signal value included in the output signal of the sub sensor 32 can be regarded as basically the same value. Therefore, the sense difference signal detection unit 11 performs a process of calculating a difference by subtracting the input signal (signal value) from the sub sensor 32 from the input signal (signal value) from the main sensor 31. That is, the sense difference signal detection unit 11 calculates the difference between the signal from the sense line 33 and the signal from the sub sense line 34. Thereby, the noise signal is removed from the output signal from the main sensor 31. Therefore, the original signal value of the touch operation generated by the touch operation can be obtained.

  In step S <b> 3, the sense difference signal value map (sense difference signal value distribution) of the sense difference signals corresponding to each intersection generated by the sense difference signal detection unit 11 can be stored in the signal distribution data storage unit 17. .

In step S4 (integration processing step), the decoding processing unit 12 integrates (or cumulatively adds) the sense difference signals arranged in the direction along the sense line S in the sense difference signal value map. That is, the sense difference signal value at the intersection S _x D _y (0 ≦ x ≦ n−1, 0 ≦ y ≦ m−1) of the n sense lines S and the m drive lines D is set to E (S when expressed as _x D _y), the intersection _S x _D and sense the difference signal value _{E (S} x _{D y)} in the _y, sense the difference signal value _E detected on one drive line _{D y} (S _{w D y)} All of (0 ≦ w ≦ x−1) are added to generate a sense signal value map (sense signal value distribution).

  In step S <b> 5, the noise presence / absence determination unit 131 determines whether or not there are a predetermined number H or more of sense difference signals indicating a signal intensity exceeding a predetermined threshold M on the same sense line S.

  In step S6 (differentiation processing step), the drive direction difference processing unit 132 generates a drive difference signal value map from the sense signal value map according to the result of the determination performed by the noise presence / absence determination unit 131. That is, when the noise presence / absence determination unit 131 determines that noise exists on the sense line S, the drive direction difference processing unit 132 calculates a drive difference signal value and creates a drive difference signal value map.

In step S7 (noise removal necessity determination step), the noise removal determination unit 133 detects a detection region P (P (S _x) in which the intensity of the drive difference signal calculated by the drive direction difference processing unit 132 is equal to or greater than a predetermined threshold N. The number of D _y )) is counted for each sense line S. For example, when the noise removal determination unit 133 detects N or more detection regions P that are equal to or greater than a predetermined threshold N on a certain sense line S _x (0 ≦ x ≦ n−1), the external noise is detected by the sensed noise. It is determined that it exists on the line _Sx .

  In step S8 (touch position detection step), the touch position detection unit 14 receives a signal equal to or greater than a predetermined threshold value Q (third threshold value) in the sense signal value map in response to a touch position detection instruction from the noise presence / absence determination unit 131. The touch position (coordinates) is determined based on the coordinates of the touch position detected as the intersection (detection region P) indicating the intensity. In addition, the touch position detection unit 14 indicates a signal intensity equal to or higher than a predetermined threshold value N (first threshold value) detected in the drive difference signal value map in response to a touch position detection instruction from the noise removal determination unit 133. Based on the coordinates of the touch position detected as the portion (detection region P), the touch position (coordinate) is determined. The processing performed by the touch position detection unit 14 will be described later using a specific example.

  Note that the threshold value Q may be set so that, for example, a position where a touch operation performed using a pen-type tool is performed can be detected.

  In step S <b> 9, the touch position detection unit 14 outputs information on the detected touch position (coordinates) to a control unit of an electronic device that uses (or has) the touch panel device 1.

  If it is determined in step S10 that noise still exists in the drive difference signal value map, the noise removal determination unit 133 outputs an instruction for noise reduction processing to the noise reduction processing unit 15. In response to the instruction, the noise reduction processing unit 15 outputs a control signal for instructing to perform noise reduction processing by frequency spreading or frequency shifting disclosed in Patent Document 2 or Patent Document 3 or the like. To supply.

  In the above description, the order of the arithmetic processing in step S4 and step S6 is shown for the case where step S4 is performed first, but the present invention is not limited to this order of calculation. This is because the signal value map obtained as a result of performing the calculation performed in step S6 first from the sense difference signal value map and then performing the calculation performed in step S4 is also used for determination of the presence of noise, detection of the touch position, and the like. Because it can.

(Specific example of processing for determining whether noise removal is necessary in touch panel device 1)
In the following, a process in which the touch panel device 1 determines necessity / unnecessity of noise removal when noise larger than a signal corresponding to a position (touch signal) corresponding to a position where the user performs a touch operation is specifically described.

Note that the touch panel 3 in the example shown in FIGS. 4 to 6 has 13 sense lines (S _{0 to} S ₁₂ ) and 15 drive lines (D _{0 to} D ₁₄ ). However, the number of sense lines S and the number of drive lines D included in the touch panel 3 are not limited to this, and may be any number of one or more.

  FIG. 4 is a diagram that three-dimensionally represents (a) a sense difference signal value map and (b) a sense difference signal value map corresponding to a touch signal in the touch panel device according to the first embodiment.

FIG. 4A illustrates a sense line in which external noise larger than the touch signal corresponds to the touch position as an example of distribution data (sense difference signal value map) of the sense difference signal value generated in the sense difference signal detection unit 11. The case where it exists in a distributed manner on S is shown. FIG. 4A shows the sense difference signal values corresponding to the sense lines S ₀ to S ₁₂ in order from the top. Here, if described row sense line S _0, each of the 4 sense the difference signal value sequence from the left to the right of (a), the sense lines S ₀ and driveline D _{0 ~} driveline D ₁₄ Sense difference signal value at the intersection P (S ₀ D _y ) (0 ≦ y ≦ 14) (that is, the sense difference signal value E (S ₀ D ₀ ) is −13, and the sense difference signal value E (S ₀ D ₁₀ ) is 23). Thus, the sense difference signal value at each intersection is shown.

FIG. 4B shows the sense difference signal map shown in FIG. 4A with the sense line S direction in the first dimension, the drive line D direction in the second dimension, and the signal intensity in the third dimension. It is a three-dimensional graph of the sense difference signal value map plotted using. In FIG. 4B, the position P (S ₆ D ₇ ) where the touch operation by the user has been performed is shown as the touch position T0. In this example, the sense difference signal value E (S ₆ D ₇ ) obtained as a result of subtraction of the signal related to the noise from the sub sense line 34 from the state signal from the sense line 33 by the sense difference signal detection unit 11 is 1636.

  Next, the decoding processing unit 12 performs cumulative addition (integration) using the sense difference signal value map shown in FIG. 4 to generate distribution data (sense signal value map) of the sense signal value. The sense difference signal value map used in the process of generating the sense signal value map may be the one input from the sense difference signal detection unit 11 or may be stored in the signal distribution data storage unit 17. You may use what was temporarily stored.

  5 shows a three-dimensional view of the sense signal value map obtained by accumulating the sense difference signal values in the sense line S direction, and (b) the sense signal value map in the sense difference signal value map of FIG. FIG.

In FIG. 5A, the sense signal values C (S _x D _y ) (0 ≦ x ≦ 12, 0 ≦ y ≦ 14) are arranged in the direction of the sense line S (that is, arranged on the same drive line). It is obtained by cumulatively adding (integrating) the sense difference signal values corresponding to the intersection P in order. Taking the sense signal value C (S ₄ D _y ) as an example, the sense difference signal value E (S ₀ D _y ), the sense difference signal value E (S ₁ D _y ), and the sense difference signal value E It is obtained by cumulatively adding (S ₂ D _y ), sense difference signal value E (S ₃ D _y ), and sense difference signal value E (S ₄ D _y ). That is, sense signal value C (S ₄ D _y ) = sense difference signal value E (S ₀ D _y ) + sense difference signal value E (S ₁ D _y ) + sense difference signal value E (S ₂ D _y ) + sense The difference signal value E (S ₃ D _y ) + the sense difference signal value E (S ₄ D _y ) is obtained. Note that, when the cumulative addition method illustrated here is used, it is desirable to assign the sense difference signal value E (S ₀ D _y ) as the sense signal value C (S ₀ D _y ) on the sense line S ₀ .

FIG. 5B shows the sense signal map shown in FIG. 5A using the sense line S direction for the first dimension, the drive line D direction for the second dimension, and the signal intensity for the third dimension. 3 is a three-dimensional graph of a sense signal value map plotted in the above manner. The sense signal value C (S ₆ D ₇ ) corresponding to the touch position T0 is 3266, and the touch position T0 cannot be detected based on this sense signal value map.

In the sense difference signal value map shown in FIG. 4, the noise presence / absence determination unit 131 includes H detection regions P that are equal to or greater than a predetermined threshold M (eg, 500) on the sense line S ₆ (a predetermined number H, eg, 3). This is detected. In this case, the noise determining unit 131, external noise is present along the sense line S _6, and determines. The noise presence / absence determination unit 131 that has determined that there is external noise instructs the drive direction difference processing unit 132 to create a drive difference signal value map.

  The drive direction difference processing unit 132 acquires the sense signal value map stored in the signal distribution data storage unit 17 in response to an instruction from the noise presence / absence determination unit 131, and drives the difference (differentiation) of the sense signal value. Calculation is performed along the line direction to generate a drive difference signal value distribution (drive difference signal value map).

  6 shows (a) a drive difference signal value map obtained as a result of obtaining a difference of sense signal values in the drive line direction and (b) a obtained drive difference signal value map in the sense signal value map of FIG. It is the figure expressed three-dimensionally.

Drive difference signal, the same sense line _{S x} sense signal values adjacent to each other on the _{C (S} x _{D y)} and the sense signal value _{C (S x D y + 1} ) of the difference _{[C (S x D y +} 1) -C (S obtained by determining the _x D _y)]. If further described by way of example, 27 drive the difference signal value _{F (S 2 D} 2) includes a 8 sense signal value _{C (S 2 D} 2) of 35 and the sense signal value _{C (S} 2 _{D 1)} (See FIG. 5).

  In FIG. 6B, the noise removal determination unit 133 indicates that the number of drive difference signals indicating a signal intensity exceeding a predetermined threshold N (for example, 500) on the same sense line S in the drive difference signal value map is a predetermined number. Since there are more than G (for example, 4) (seven), it is determined that noise removal is necessary. When it is determined that there is external noise, the noise removal determination unit 133 outputs a noise reduction processing instruction to the noise reduction processing unit 15.

  In response to an instruction from the noise removal determination unit 133, the noise reduction processing unit 15 instructs to perform noise reduction processing by frequency spreading or frequency shifting disclosed in Patent Document 2 or Patent Document 3 or the like. The signal is supplied to the touch panel control unit 16.

[Embodiment 2]
(Specific example of touch position detection processing in the touch panel device 1)
In the following, (1) When a large noise is mixed in a signal (touch signal) corresponding to the position where the user performs a touch operation (1) (FIGS. 7 to 9), and (2) When a large noise is mixed 2 (FIGS. 10 to 12), (3) When there is no noise (FIGS. 13 to 15), and (4) When small noise is mixed (FIGS. 16 to 18), the touch panel device 1 determines the touch position. The process of detecting and the process of determining whether noise removal is necessary are specifically shown.

Note that the touch panel 3 in the example illustrated in FIGS. 7 to 18 includes 13 sense lines (S _{0 to} S ₁₂ ) and 15 drive lines (D _{0 to} D ₁₄ ). However, the number of sense lines S and the number of drive lines D included in the touch panel 3 are not limited to this, and may be any number of one or more.

(1) When large noise is mixed 1
FIG. 7 is a diagram three-dimensionally representing (a) a sense difference signal value map and (b) a sense difference signal value map corresponding to a touch signal in the touch panel device according to the first embodiment.

FIG. 7A shows an example of sense difference signal value distribution data (sense difference signal value map) generated by the sense difference signal detection unit 11 and sense lines in which external noise larger than the touch signal corresponds to the touch position. The case where it exists in a distributed manner on S is shown. FIG. 7A shows the sense difference signal values corresponding to the sense lines S ₀ to S ₁₂ in order from the top. Here, to explain the row of the sense line S ₀ , the sense difference signal values arranged from the left to the right in FIG. 7A are the sense line S ₀ and each of the drive lines D ₀ to D ₁₄ . Is the sense difference signal value at the intersection P (S ₀ D _y ) (0 ≦ y ≦ 14) (that is, the sense difference signal value E (S ₀ D ₀ ) is 30, and the sense difference signal value E ( S ₀ D ₁₀ ) is 70). Thus, the sense difference signal value at each intersection is shown.

FIG. 7B shows the sense difference signal map shown in FIG. 7A with the sense line S direction in the first dimension, the drive line D direction in the second dimension, and the signal intensity in the third dimension. It is a three-dimensional graph of the sense difference signal value map plotted using. In FIG. 7B, the position P (S ₅ D ₇ ) where the touch operation by the user has been performed is shown as the touch position T1. In this example, the sense difference signal value E (S ₅ D ₇ ) obtained as a result of subtraction of the signal related to the noise from the sub sense line 34 from the state signal from the sense line 33 by the sense difference signal detection unit 11 is -2817.

  Next, the decoding processing unit 12 performs cumulative addition (integration) using the sense difference signal value map shown in FIG. 7 to generate sense signal value distribution data (sense signal value map). The sense difference signal value map used in the process of generating the sense signal value map may be the one input from the sense difference signal detection unit 11 or may be stored in the signal distribution data storage unit 17. You may use what was temporarily stored.

  8 shows a three-dimensional view of the sense signal value map obtained by accumulating the sense difference signal values in the sense line S direction and (b) the sense signal value map in the sense difference signal value map of FIG. FIG.

In FIG. 8A, the sense signal value C (S _x D _y ) (0 ≦ x ≦ 12, 0 ≦ y ≦ 14) is a sense difference signal value corresponding to each intersection P arranged in the direction of the sense line S. Are sequentially accumulated (integrated). Taking the sense signal value C (S ₂ D _y ) as an example, the sense differential signal value E (S ₀ D _y ), the sense differential signal value E (S ₁ D _y ), and the sense differential signal value E (S ₂ D _y ) and the cumulative addition. That is, the sense signal value C (S ₂ D _y ) = sense difference signal value E (S ₀ D _y ) + sense difference signal value E (S ₁ D _y ) + sense difference signal value E (S ₂ D _y ) It is done. Note that, when the cumulative addition method illustrated here is used, it is desirable to assign the sense difference signal value E (S ₀ D _y ) as the sense signal value C (S ₀ D _y ) on the sense line S ₀ .

FIG. 8B shows the sense signal map shown in FIG. 8A using the sense line S direction for the first dimension, the drive line D direction for the second dimension, and the signal intensity for the third dimension. 3 is a three-dimensional graph of a sense signal value map plotted in the above manner. The sense signal value C (S ₅ D ₇ ) corresponding to the touch position T1 is −469, and the touch position T1 cannot be detected based on this sense signal value map.

In the sense difference signal value map illustrated in FIG. 7, the noise presence / absence determination unit 131 includes H detection regions P that are equal to or greater than a predetermined threshold M (for example, 500) on the sense lines S ₄ and S ₇ (a predetermined number H, For example, 3) or more are detected. In this case, the noise presence / absence determination unit 131 determines that there is external noise along the sense lines S ₄ and S ₇ . The noise presence / absence determination unit 131 that has determined that there is external noise instructs the drive direction difference processing unit 132 to create a drive difference signal value map.

  The drive direction difference processing unit 132 acquires the sense signal value map stored in the signal distribution data storage unit 17 in response to an instruction from the noise presence / absence determination unit 131, and drives the difference (differentiation) of the sense signal value. Calculation is performed along the line direction to generate a drive difference signal value distribution (drive difference signal value map).

  FIG. 9 shows (a) a drive difference signal value map obtained as a result of obtaining a difference between sense signal values in the drive line direction, and (b) a obtained drive difference signal value map in the sense signal value map of FIG. It is the figure expressed three-dimensionally.

Drive difference signal, the same sense line _{S x} sense signal values adjacent to each other on the _{C (S} x _{D y)} and the sense signal value _{C (S x D y + 1} ) of the difference _{[C (S x D y +} 1) -C (S obtained by determining the _x D _y)]. If further described by way of example, 11 drive the difference signal value _{F (S} 2 _{D 3)} includes a 90 sense signal values _C 101 and the sense signal value _{(S 2 D 3) C (} S 2 D 2) (See FIG. 8).

  According to FIG. 9B, a signal intensity exceeding a predetermined threshold N is shown at a position corresponding to the touch position T1 that is not detected in the sense signal value map. As described above, the signal derived from the external noise is canceled by taking a difference (differentiating) in the drive line direction. As a result, the touch signal corresponding to the touch position T1 corresponds to the position (coordinates) corresponding to the touch position T1. It has become obvious. In the drive difference signal value map, the noise removal determination unit 133 determines that the number of drive difference signals indicating a signal intensity exceeding a predetermined threshold N (for example, 1000) on the same sense line S is a predetermined number G (for example, 4). Since there are few (two), it is determined that noise removal is unnecessary. The touch position detection unit 14 detects a position indicating a signal intensity exceeding a predetermined threshold Q in the drive difference signal value map as the touch position T1.

  Information regarding the position (coordinates) corresponding to the touch position T1 detected by the touch position detection unit 14 is output to the control unit of the electronic device including the touch panel device 1.

(2) When large noise is mixed 2
FIG. 10 is a diagram that three-dimensionally represents (a) a sense difference signal value map and (b) a sense difference signal value map corresponding to a touch signal in the touch panel device according to the first embodiment of the present invention.

FIG. 10A shows an example of sense difference signal value distribution data (sense difference signal value map) generated by the sense difference signal detection unit 11, in which external noise having the same level as the signal strength of the touch signal is detected at the touch position. Is shown in a distributed manner on the sense line S corresponding to. FIG. 10A shows the sense difference signal values corresponding to the sense lines S ₀ to S ₁₂ in order from the top.

FIG. 10B shows the sense difference signal map shown in FIG. 10A with the sense line S direction in the first dimension, the drive line D direction in the second dimension, and the signal intensity in the third dimension. It is a three-dimensional graph of the sense difference signal value map plotted using. In FIG. 10B, the position P (S ₇ D ₄ ) where the touch operation by the user has been performed is the touch position T2. In this example, the sense difference signal value E (S ₇ D ₄ ) obtained as a result of subtraction of the signal related to the noise from the sub sense line 34 from the state signal from the sense line 33 by the sense difference signal detection unit 11 is 2908.

  Next, the decoding processing unit 12 performs cumulative addition (integration) using the sense difference signal value map illustrated in FIG. 10 to generate sense signal value distribution data (sense signal value map). The sense difference signal value map used in the process of generating the sense signal value map may be the one input from the sense difference signal detection unit 11 or may be stored in the signal distribution data storage unit 17. You may use what was temporarily stored.

  FIG. 11 shows a three-dimensional view of the sense signal value map obtained by accumulating the sense difference signal values in the sense line S direction and (b) the sense signal value map in the sense difference signal value map of FIG. FIG.

In FIG. 11A, the sense signal values C (S _x D _y ) (0 ≦ x ≦ 12, 0 ≦ y ≦ 14) are arranged in the sense line S direction (that is, arranged on each drive line). It is obtained by cumulatively adding (integrating) the sense difference signal values corresponding to the portion P in order.

FIG. 11B shows the sense signal map shown in FIG. 11A using the sense line S direction for the first dimension, the drive line D direction for the second dimension, and the signal intensity for the third dimension. 3 is a three-dimensional graph of a sense signal value map plotted in the above manner. The sense signal value C (S ₇ D ₄ ) corresponding to the touch position T2 is 3895, and the touch position T2 cannot be detected based on this sense signal value map. This is because, for example, on the sense line S ₇ and the sense line S ₈ , a signal intensity lower than the touch position T 2 but a signal exceeding a predetermined threshold value M (first threshold value, eg 500) is a predetermined number H. This is because (for example, 4) or more exist.

When the noise presence / absence determination unit 131 detects H (predetermined number H, for example, 3) or more detection regions P that are equal to or greater than a predetermined threshold on the sense line _Sx in the sense difference signal value map illustrated in FIG. Determines that there is external noise along the sense line _Sx . On the sense line S _7, since the number of the detection region P is equal to or greater than a predetermined threshold value is 15, external noise is present, it is determined that. Therefore, the noise presence / absence determination unit 131 instructs the drive direction difference processing unit 132 to create a drive difference signal value map.

  The drive direction difference processing unit 132 acquires the sense signal value map stored in the signal distribution data storage unit 17 in response to an instruction from the noise presence / absence determination unit 131, and drives the difference (differentiation) of the sense signal value. Calculation is performed along the line direction to generate a drive difference signal value distribution (drive difference signal value map).

  12 shows (a) a drive difference signal value map obtained as a result of obtaining a difference between sense signal values in the drive line direction, and (b) a obtained drive difference signal value map in the sense signal value map of FIG. It is the figure expressed three-dimensionally.

The drive differential signal is the difference between the sense signal value C (S _x D _y ) and the sense signal value C (S _x D _{y + 1} ) adjacent to each other on the same sense line S _x , for example, [C (S _x D _{y + 1} ) − C (S _x D _y )] is obtained.

  According to FIG. 12B, noise-derived signals other than the touch position T2 detected in the sense signal value map are removed, and a signal intensity exceeding a predetermined threshold is detected only at a position corresponding to the touch position T2. doing. In this way, the signal derived from the external noise is canceled by taking a difference (differentiating) in the drive line direction. As a result, the touch signal corresponding to the touch position T2 corresponds to the position (coordinates) corresponding to the touch position T2. To manifest. In the drive difference signal value map, the noise removal determination unit 133 determines that the number of drive difference signals indicating a signal intensity exceeding a predetermined threshold N (for example, 1000) on the same sense line S is a predetermined number G (for example, 4). Since there are few (two or less), it is determined that noise removal is unnecessary. The touch position detection unit 14 detects a position indicating a signal intensity exceeding a predetermined threshold in the drive difference signal value map as the touch position T2.

  Information relating to the position (coordinates) corresponding to the touch position T2 detected by the touch position detection unit 14 is output to the control unit of the electronic device including the touch panel device 1.

(3) When no noise is mixed FIG. 13 shows three (a) sense difference signal value maps and (b) sense difference signal value maps corresponding to touch signals in the touch panel device according to the first embodiment of the present invention. FIG.

FIG. 13A shows a case where no external noise is mixed in the touch signal as an example of distribution data (sense difference signal value map) of the sense difference signal value generated in the sense difference signal detection unit 11. . FIG. 13A shows the sense difference signal values corresponding to the sense lines S ₀ to S ₁₂ in order from the top.

FIG. 13B shows the sense difference signal map shown in FIG. 13A with the sense line S direction in the first dimension, the drive line D direction in the second dimension, and the signal intensity in the third dimension. It is a three-dimensional graph of the sense difference signal value map plotted using. In FIG. 13B, the position P (S ₆ D ₈ ) where the touch operation by the user has been performed is the touch position T3. In this example, the sense difference signal value E (S ₆ D ₈ ) obtained as a result of subtraction of the signal related to the noise from the sub sense line 34 from the state signal from the sense line 33 by the sense difference signal detection unit 11 is 7597.

  Next, the decoding processing unit 12 performs cumulative addition (integration) using the sense difference signal value map shown in FIG. 13 to generate sense signal value distribution data (sense signal value map). The sense difference signal value map used in the process of generating the sense signal value map may be the one input from the sense difference signal detection unit 11 or may be stored in the signal distribution data storage unit 17. You may use what was temporarily stored.

  FIG. 14 is a three-dimensional representation of (a) a sense signal value map obtained by cumulatively adding sense difference signal values in the sense line direction, and (b) a sense signal value map in the sense difference signal value map of FIG. FIG.

In FIG. 14A, sense signal values C (S _x D _y ) (0 ≦ x ≦ 12, 0 ≦ y ≦ 14) are arranged in the sense line S direction (that is, arranged on each drive line). It is obtained by cumulatively adding (integrating) the sense difference signal values corresponding to the portion P in order.

FIG. 14B shows the sense signal map shown in FIG. 14A using the sense line S direction for the first dimension, the drive line D direction for the second dimension, and the signal intensity for the third dimension. 3 is a three-dimensional graph of a sense signal value map plotted in the above manner. The sense signal value C (S ₆ D ₈ ) corresponding to the touch position T3 is 12111, and the touch position T3 is detected based on this sense signal value map. This is because there are no more than a predetermined number H (for example, 4) of signals indicating a signal intensity exceeding a predetermined threshold M (for example, 3000) on the same sense line S.

  As described above, since the sense signal value obtained by cumulatively adding (integrating) the sense difference signal value has a signal strength larger than that of the sense difference signal value, a signal corresponding to the touch signal can be enlarged.

When the noise presence / absence determination unit 131 detects H (predetermined number H, for example, 4) or more detection regions P that are equal to or greater than a predetermined threshold on the sense line _Sx in the sense difference signal value map illustrated in FIG. Determines that there is external noise along the sense line _Sx . For example, on each sense line S _x , the number of detection regions P that are equal to or greater than a predetermined threshold is 3 or less, so the noise presence / absence determination unit 131 determines that there is no external noise (no noise). Therefore, the noise presence / absence determination unit 131 outputs information on the position (coordinates) corresponding to the detected touch position T3 in FIG. 14 to the control unit of the electronic device including the touch panel device 1 in FIG. The

  In the following, a supplemental description will be given of a case where a drive difference signal value map creation instruction is output to the drive direction difference processing unit 132.

  The drive direction difference processing unit 132 acquires the sense signal value map stored in the signal distribution data storage unit 17 in response to an instruction from the noise presence / absence determination unit 131, and drives the difference (differentiation) of the sense signal value. Calculation is performed along the line direction to generate a drive difference signal value distribution (drive difference signal value map).

  FIG. 15 shows (a) a drive difference signal value map obtained as a result of obtaining a difference between sense signal values in the drive line direction, and (b) a obtained drive difference signal value map in the sense signal value map of FIG. It is the figure expressed three-dimensionally.

Drive difference signal, the same sense line _{S x} sense signal values adjacent to each other on the _{C (S} x _{D y)} and the sense signal value _{C (S x D y + 1} ) of the difference _{[C (S x D y +} 1) -C (S obtained by determining the _x D _y)].

  According to FIG. 15B, in the sense signal value map, the signal intensity exceeding the predetermined threshold is detected only at the position corresponding to the touch position T3. In the drive difference signal value map, the noise removal determination unit 133 determines that the number of drive difference signals indicating a signal intensity exceeding a predetermined threshold N (for example, 1000) on the same sense line S is a predetermined number G (for example, 4). Since there are few (two or less), it is determined that noise removal is unnecessary. The touch position detection unit 14 detects a position indicating a signal intensity exceeding a predetermined threshold in the drive difference signal value map as the touch position T3.

  Information relating to the position (coordinates) corresponding to the touch position T2 detected by the touch position detection unit 14 is output to the control unit of the electronic device including the touch panel device 1.

  However, in the example shown in FIGS. 13 to 15, the touch position T3 can already be detected in the sense signal value map. Therefore, as described above, it is not necessary to create a drive difference signal value map. That is, when the noise presence / absence determination unit 131 determines that no noise exists (no noise), the noise presence / absence determination unit 131 may send a touch position detection instruction to the touch position detection unit 14.

(4) When there is small noise mixing FIG. 16 shows (a) a sense difference signal value map and (b) a sense difference signal value map corresponding to a touch signal in the touch panel device according to Embodiment 1 of the present invention. It is the figure expressed three-dimensionally.

FIG. 16A shows an example of sense difference signal value distribution data (sense difference signal value map) generated by the sense difference signal detection unit 11, and external noise that is smaller than the signal strength of the touch signal is present at the touch position. The case where it exists in a distributed manner on the corresponding sense line S is shown. FIG. 16A shows sense difference signal values corresponding to the sense lines S ₀ to S ₁₂ in order from the top.

FIG. 16B shows the sense difference signal map shown in FIG. 16A with the sense line S direction in the first dimension, the drive line D direction in the second dimension, and the signal intensity in the third dimension. It is a three-dimensional graph of the sense difference signal value map plotted using. In FIG. 16B, the position P (S ₇ D ₇ ) where the touch operation by the user is performed is the touch position T4. In this example, the sense difference signal value E (S ₇ D ₇ ) obtained as a result of subtraction of the signal related to the noise from the sub sense line 34 from the state signal from the sense line 33 by the sense difference signal detection unit 11 is 4668.

  Next, the decoding processing unit 12 performs cumulative addition (integration) using the sense difference signal value map shown in FIG. 16 to generate sense signal value distribution data (sense signal value map). The sense difference signal value map used in the process of generating the sense signal value map may be the one input from the sense difference signal detection unit 11 or may be stored in the signal distribution data storage unit 17. You may use what was temporarily stored.

  17 shows a three-dimensional view of the sense signal value map obtained by accumulating the sense difference signal values in the sense line S direction and (b) the sense signal value map in the sense difference signal value map of FIG. FIG.

In FIG. 17A, sense signal values C (S _x D _y ) (0 ≦ x ≦ 12, 0 ≦ y ≦ 14) are arranged in the sense line S direction (that is, arranged on each drive line). It is obtained by cumulatively adding (integrating) the sense difference signal values corresponding to the portion P in order.

FIG. 17B shows the sense signal map shown in FIG. 17A using the sense line S direction for the first dimension, the drive line D direction for the second dimension, and the signal intensity for the third dimension. 3 is a three-dimensional graph of a sense signal value map plotted in the above manner. The sense signal value C (S ₇ D ₇ ) corresponding to the touch position T4 is 7349, and the touch position T3 is detected based on this sense signal value map. This is because there are no more than a predetermined number H (for example, 4) of signals indicating a signal intensity exceeding a predetermined threshold M (for example, 3000) on the same sense line S.

  As described above, since the sense signal value obtained by cumulatively adding (integrating) the sense difference signal value has a signal strength larger than that of the sense difference signal value, a signal corresponding to the touch signal can be enlarged.

In the sense difference signal value map shown in FIG. 16, the noise presence / absence determination unit 131 detects H (predetermined number H, for example, 4) or more detection regions P that are equal to or greater than a predetermined threshold on the sense line _Sx. Determines that there is external noise along the sense line _Sx . For example, on each sense line S _x , the number of detection regions P that are equal to or greater than a predetermined threshold is 3 or less, so the noise presence / absence determination unit 131 determines that there is no external noise (no noise). Therefore, the noise presence / absence determination unit 131 outputs, to the touch position detection unit 14, information related to the position (coordinates) corresponding to the detected touch position T <b> 4 in FIG. 14 to the control unit of the electronic device including the touch panel device 1. The

  In the following, a supplemental description will be given of a case where a drive difference signal value map creation instruction is output to the drive direction difference processing unit 132.

  The drive direction difference processing unit 132 acquires the sense signal value map stored in the signal distribution data storage unit 17 in response to an instruction from the noise presence / absence determination unit 131, and drives the difference (differentiation) of the sense signal value. Calculation is performed along the line direction to generate a drive difference signal value distribution (drive difference signal value map).

  18 shows (a) a drive difference signal value map obtained as a result of obtaining a difference of sense signal values in the drive line direction and (b) a obtained drive difference signal value map in the sense signal value map of FIG. It is the figure expressed three-dimensionally.

Drive difference signal value, the same sense line _{S x} sense signal values adjacent to each other on the _{C (S} x _{D y)} and the sense signal value _{C (S x D y + 1} ) of the difference _{[C (S x D y +} 1) -C ( S _x D _y )] is obtained. Incidentally, the difference _{[C (S x D y)} -C (S x D y + 1)] may be used as drive differential signal values.

  According to FIG. 18B, in the sense signal value map, a signal intensity exceeding a predetermined threshold is detected only at a position corresponding to the touch position T4. In the drive difference signal value map, the noise removal determination unit 133 has a predetermined number G (for example, 4) or more of drive difference signals that indicate a signal intensity exceeding a predetermined threshold value N (for example, 1000) on the same sense line S. Since it exists, it is determined that noise removal is necessary.

  However, in the example shown in FIGS. 16 to 18, the touch position T4 can already be detected in the sense signal value map. Therefore, as described above, it is not necessary to create a drive difference signal value map. That is, when the noise presence / absence determination unit 131 determines that no noise exists (no noise), the noise presence / absence determination unit 131 may send a touch position detection instruction to the touch position detection unit 14.

[Embodiment 3]
(Touch panel 3 of touch panel device 1)
The touch panel device 1 including the capacitive touch panel 3 has been described. However, the operation principle (sensor operation method) of the touch panel 3 is not limited to the capacitance method. For example, a touch panel device including a resistive film type, infrared type, ultrasonic type, or electromagnetic inductive coupling type touch panel similarly exhibits a noise detection function and a touch position detection function. Moreover, the noise canceling function is exhibited regardless of the type of the display device 2.

[Example of software implementation]
The control blocks (particularly the noise determination unit 13 and the touch panel control unit 16) of the touch panel device 1 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or a CPU (Central Processing Unit). ) May be implemented by software.

  In the latter case, the touch panel device 1 includes a CPU that executes instructions of a program that is software that implements each function, a ROM (Read Only Memory) in which the program and various data are recorded so as to be readable by a computer (or CPU), or A storage device (these are referred to as “recording media”), a RAM (Random Access Memory) that expands the program, and the like are provided. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

[Summary]
The touch panel device 1 according to the first aspect of the present invention includes a plurality of first signal lines (sense line 33, sense line S) extending substantially parallel to the first direction, and a second orthogonal to the first direction. A plurality of second signal lines (drive line 35, drive line D) extending substantially parallel to the direction, and capacitance values formed at respective intersections of the first signal line and the second signal line The touch panel 3 that acquires the signal strength of the first signal value (sense difference signal value) corresponding to the (status signal), and the touch position that receives the touch operation by the user is the signal of the touch signal that corresponds to the capacitance value. And a touch position detection unit that detects based on intensity, and integrates the first signal value along the second signal line to generate a second signal value (sense signal value). Integral to And a differential processing unit (drive direction differential processing unit) that differentiates the second signal value along the first signal line to generate a third signal value (drive differential signal value). 132) and the third signal value indicating the signal intensity exceeding the predetermined first threshold value (threshold value N) is present on the same first signal line by the first predetermined number (predetermined number G) or more. A noise removal necessity determination unit (noise removal determination unit 133) that determines that external noise that prevents detection of the touch position is mixed in the signal.

  In addition, the control method of the touch panel device 1 according to the first aspect of the present invention includes a plurality of first signal lines extending substantially parallel to the first direction and a substantially parallel to the second direction orthogonal to the first direction. The signal strength of the first signal value corresponding to the capacitance value formed at each intersection of the first signal line and the second signal line is obtained. This is a control method for the touch panel device 1 including the touch panel 3 and a touch position detection unit 14 that detects a touch position that has been touched by a user based on the signal strength of a touch signal corresponding to the capacitance value. And integrating the first signal value along the second signal line to generate a second signal value (S4), and differentiating the second signal value along the first signal line. To produce the third signal value And when there is a first predetermined number or more of the third signal value indicating a signal intensity exceeding a predetermined first threshold on the same first signal line, the touch signal includes the touch position of the touch position. And a noise removal necessity determination step (S7) for determining that external noise that prevents detection is mixed.

  According to the configuration and the control method described above, after integrating the first signal value along the second signal line, the second signal value is differentiated along the first signal line to generate the third signal value.

  Thereby, the external noise generated by being distributed on the first signal line is canceled by differentiating the second signal value along the first signal line, and the obtained third signal value is caused by the signal derived from the external noise. The impact can be attenuated. As a result, a touch signal corresponding to the touch position can be detected.

  In the touch panel device, when the touch panel accepts a touch operation by the user, the external noise mixed with the capacitance at the position corresponding to the touch operation is generated on the touch panel, and the touch is performed even in the third signal value. It is determined that external noise that interferes with position detection is mixed.

  Thereby, when the external noise mixed in the touch signal is detected even in the third signal value, a noise removal method suitable for removing the noise can be accurately used.

  In the touch panel device according to aspect 2 of the present invention, in the aspect 1, the touch position detection unit 14 has the same first signal value indicating a signal intensity exceeding a predetermined second threshold value (threshold value M). In the case where the number is smaller than a second predetermined number (predetermined number H) on one signal line, a position where the second signal value exceeds a predetermined third threshold (threshold Q) may be detected as the touch position. .

  According to the above configuration, when a signal other than the touch signal is not detected in the first signal value on the first signal line, the touch position is detected based on the signal strength of the second signal value. Since the signal intensity of the second signal value obtained by integrating the first signal value is larger than that of the first signal value, the signal corresponding to the touch signal can be enlarged.

  Thereby, a position indicating the signal intensity of the second signal value indicating sufficient intensity can be detected as the touch position. Therefore, it is possible to detect the touch signal with high sensitivity.

  In the touch panel device 1 according to the aspect 3 of the present invention, in the aspect 1 or 2, the touch panel 3 includes the main sensor unit (main sensor 31) that detects the capacitance corresponding to the touch operation, and the touch operation. And a sub-sensor unit (sub-sensor 32) for detecting various noises generated on the touch panel, and the first signal value is obtained by subtracting the signal from the sub-sensor unit from the signal from the main sensor unit. It may be a difference value obtained as described above.

  According to this configuration, the difference between the signal from the main sensor unit and the signal from the sub sensor unit is obtained.

  Thereby, the signal resulting from random noise generated on the touch panel is removed from the output signal from the main sensor 31. Therefore, the original signal value of the touch operation generated by the touch operation can be obtained.

The touch panel device according to aspect 4 of the present invention is the touch panel device according to any one of the aspects 1 to 3, wherein the integration processing unit includes n (n ≧ 1) first signal lines S and m (m ≧ 1). ), The first signal value at the intersection S _x D _y (0 ≦ x ≦ n−1, 0 ≦ y ≦ m−1) with the second signal line D is represented by E (S _x D _y ), If the second signal value at the intersection S _x D _y is expressed as C (S _x D _y ), the second signal value C (S _x D _y ) is used as the first signal on the second signal line D _y . A value obtained by adding the signal values from E (S ₀ D _y ) to E (S _x D _y ) is assigned.

  According to this configuration, the second signal value corresponding to the first signal value is assigned to each intersection.

  As a result, the second signal value at each intersection is a value corresponding to the signal intensity at each intersection of the first signal value. Therefore, the touch position can be detected based on the second signal value corresponding to the same position as the position where the first signal value corresponding to the touch position is detected.

The touch panel device according to aspect 5 of the present invention is the touch panel device according to any one of the aspects 1 to 4, wherein the integration processing unit includes the n first signal lines S and the m second signal lines D. The second signal value in the intersection portion S _x D _y (0 ≦ x ≦ n−1, 0 ≦ y ≦ m−1) is C (S _x D _y ), and the second signal value in the intersection portion S _x D _y is expressed three signal values _{F (S} x _{D y),} as the third signal value _{F (S} x _{D y),} present on the second signal line _{D y,} the difference between the second signal value adjacent , a value obtained by calculating any one of _{(C (S x D y +} 1) -C (S x D y)), _{or, (C (S x D y} ) -C (S x D y + 1)) Assign.

  According to this configuration, the third signal value corresponding to the second signal value is assigned to each intersection.

  As a result, the third signal value at each intersecting portion becomes a value corresponding to the signal intensity at each intersecting portion of the second signal value. Therefore, the touch position can be detected based on the third signal value corresponding to the same position as the position where the second signal value corresponding to the touch position is detected.

  The touch panel device 1 according to each aspect of the present invention may be realized by a computer. In this case, the touch panel device 1 is realized by a computer by causing the computer to operate as each unit included in the touch panel device 1. The control program of the apparatus 1 and a computer-readable recording medium on which the control program is recorded also fall within the scope of the present invention.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  The touch panel device of the present embodiment can be applied to various touch panel electronic devices. Thereby, the electronic device which can suppress effectively the misdetection of the position by which the touch operation was carried out can be provided. Examples of electronic devices include televisions, personal computers, mobile phones, smartphones, digital cameras, portable game machines, electronic photo frames, personal digital assistants (PDAs), electronic books, home appliances (microwave ovens, laundry Machine), ticket machines, ATM (Automated Teller Machine), car navigation, and the like.

DESCRIPTION OF SYMBOLS 1 Touch panel apparatus 2 Display apparatus 3 Touch panel 10 Drive line drive part 11 Sense difference signal detection part 12 Decoding process part (integration process part)
DESCRIPTION OF SYMBOLS 13 Noise determination part 14 Touch position detection part 16 Touch panel control part 17 Signal distribution data storage part 31 Main sensor (main sensor part)
32 Sub sensor (sub sensor part)
33 sense line (first signal line)
34 sub sense line 35 drive line (second signal line)
131 Noise presence / absence determination unit 132 Drive direction difference processing unit (differentiation processing unit)
133 Noise removal determination unit (noise removal necessity determination unit)
S4 Integration processing step S6 Differentiation processing step S7 Noise removal necessity determination step S8 Touch position detection step

Claims (6)

A plurality of first signal lines extending substantially parallel to the first direction, and a plurality of second signal lines extending substantially parallel to a second direction orthogonal to the first direction. And a touch panel for acquiring the signal intensity of the first signal value corresponding to the capacitance value respectively formed at each intersection of the second signal line, and
A touch position detection unit that detects a touch position that has been touched by a user based on a signal intensity of a touch signal corresponding to the capacitance value;
A touch panel device having
An integration processing unit that integrates the first signal value along the second signal line to generate a second signal value;
Differentiating the second signal value along the first signal line to generate a third signal value;
When the third signal value indicating the signal intensity exceeding the predetermined first threshold is present on the same first signal line in the first predetermined number or more, external noise that prevents detection of the touch position is mixed in the touch signal. A noise removal necessity determination unit that determines that the
A touch panel device characterized by that. The touch position detection unit
When the first signal value indicating the signal strength exceeding the predetermined second threshold value is less than the second predetermined number on the same first signal line, the signal strength exceeding the predetermined third threshold value. Detecting the position indicating as the touch position,
The touch panel device according to claim 1. The touch panel
A main sensor unit for detecting the capacitance corresponding to the touch operation;
A sub sensor unit for detecting various noises generated on the touch panel regardless of the touch operation,
The first signal value is
The difference value obtained by subtracting the signal from the sub sensor unit from the signal from the main sensor unit,
The touch panel device according to claim 1 or 2. The integration processing unit
The intersection portion S _x D _y (0 ≦ x ≦ n−1, 0 ≦ y) of the n (n ≧ 1) first signal lines S and the m (m ≧ 1) second signal lines D. ≦ m-1 the first signal value _{in) E (S x D y)} , if indicated the second signal value and _{C (S} x _{D y)} in the intersection _S x _{D y,}
As the second signal value C (S _x D _y ), a value obtained by adding the first signal value on the second signal line D _y from E (S ₀ D _y ) to E (S _x D _y ) is obtained. assign,
The touch panel device according to claim 1, wherein the touch panel device is a touch panel device. The integration processing unit
The second in (0 ≦ x ≦ n−1, 0 ≦ y ≦ m−1) at the intersection S _x D _y of the n first signal lines S and the m second signal lines D. a signal value _C (S _{x D} y), if indicated the third signal value in the intersection _S x _{D y} and _{F (S} x _{D y),}
As the third signal value F (S _x D _y ), the difference between the second signal values existing on the first signal line S _x and adjacent to each other, (C (S _x D _{y + 1} ) −C (S _x D) _y )) or (C (S _x D _y ) -C (S _x D _{y + 1} ))
The touch panel device according to claim 1, wherein the touch panel device is a touch panel device. A plurality of first signal lines extending substantially parallel to the first direction, and a plurality of second signal lines extending substantially parallel to a second direction orthogonal to the first direction. And a touch panel for acquiring the signal intensity of the first signal value corresponding to the capacitance value respectively formed at each intersection of the second signal line, and
A touch position detection unit that detects a touch position that has been touched by a user based on a signal intensity of a touch signal corresponding to the capacitance value;
A touch panel device control method comprising:
An integration step of integrating the first signal value along the second signal line to generate a second signal value;
Differentiating the second signal value along the first signal line to generate a third signal value;
When the third signal value indicating the signal intensity exceeding the predetermined first threshold is present on the same first signal line in the first predetermined number or more, external noise that prevents detection of the touch position is mixed in the touch signal. Including a step of determining whether noise removal is necessary,
A control method for a touch panel device.

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