JP2021165876A - Touch panel apparatus and control method of touch panel apparatus - Google Patents

Abstract

To provide a touch panel apparatus capable of reducing processing load by a noise filter.SOLUTION: A touch panel apparatus 100 includes: a touch panel 1 by a mutual capacitance system; an extraction unit 6 that extract at least one certain first electrode 2 corresponding to a touch coordinate from the plurality of first electrodes 2;, and a coordinate identification unit 7 that extracts at least one certain second electrode 3 corresponding to a touch coordinate from the plurality of second electrodes 3, applies a first nose filter to a measurement value corresponding to an intersection point of the extracted first electrode 2 and the extracted second electrode 3, and identifies a touch coordinate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a touch panel device that detects external noise in a mutual capacitance type touch panel and counteracts the noise.

In recent years, touch panels have been widely used as input means for users to operate not only in electronic devices such as mobile terminals and PDAs (Personal Digital Assistants) but also in street advertisements and operation panels of industrial products. In particular, a touch panel equipped with a detection principle of a capacitance method mainly a mutual capacitance method is used in many applications as compared with other methods.

The mutual capacitance type touch panel identifies the touch coordinates from the characteristic pattern of the signal input from the sensor. Here, when noise is superimposed on the input from the sensor, the characteristic pattern of the signal is disturbed or formed. As a result, an error is brought about in the operation based on the input from the touch panel.

As a prior art, a mutual capacitance type touch panel including a process for countering the above noise is known. For example, Patent Document 1 describes a capacitance distribution detection method capable of removing the influence of phantom noise (external noise) caused by touching a panel such as a human hand or finger that has received electromagnetic noise. It is disclosed.

Japanese Patent No. 5539269

However, in the method described in Patent Document 1, it is necessary to apply a noise filter to the entire signal obtained from the receiving electrode before detecting the capacitance distribution. Therefore, when there is strong noise, it is necessary to apply a strong noise filter to the entire signal obtained from the receiving electrode, and there is a problem that the performance of the touch panel device is significantly deteriorated.

One aspect of the present invention has been made in view of the above problems, and an object of the present invention is to provide a touch panel device capable of reducing a processing load by a noise filter.

In order to solve the above problems, the touch panel device according to one aspect of the present invention includes a plurality of first electrodes and a plurality of second electrodes intersecting the plurality of first electrodes, and the plurality of first electrodes and the plurality of first electrodes. A touch panel by a mutual capacitance method that forms a plurality of capacitance couplings at intersections with a plurality of second electrodes, a second electrode driving unit that applies a driving voltage to the plurality of second electrodes, and the plurality of electrodes. Based on the measurement values for each of the first electrode measuring unit for measuring the output from the first electrode and the first electrode measuring unit obtained by the first electrode measuring unit when the second electrode driving unit applies the driving voltage. An extraction unit that extracts at least one specific first electrode corresponding to the touch coordinates from the plurality of first electrodes, and a first electrode driving unit that applies a driving voltage to the plurality of first electrodes. When the second electrode measuring unit that measures the output from the plurality of second electrodes and the first electrode driving unit applies the driving voltage to the specific first electrode, the second electrode measuring unit obtains the results. Based on the measured value for each of the second electrodes, at least one specific second electrode corresponding to the touch coordinates is extracted from the plurality of second electrodes, and the extracted at least one specific first electrode is used. A first noise filter is applied to the measured value corresponding to the extracted intersection with the specific at least one second electrode, and a coordinate specifying unit for specifying the touch coordinates is provided.

According to the above configuration, the touch panel device can measure the output corresponding to the capacitance coupling from both directions of the first electrode and the second electrode. The effect of noise entering through a finger or the like appears along the receiving electrode near the touch coordinates. Therefore, the touch panel device extracts the output of the region to which the first noise filter should be applied based on the measured values of the outputs of the first electrode and the second electrode, and applies the noise filter to the extracted output. be able to. Therefore, the touch panel device can reduce the processing load of the noise filter. Thereby, for example, even when the noise superimposed on the output of the receiving electrode is strong, the touch coordinates can be specified in a short time.

Further, the extraction unit does not apply the first noise filter to the measured values for each of the first electrodes obtained by the first electrode measuring unit when the second electrode driving unit applies the driving voltage. The coordinate specifying unit is the identification extracted from a plurality of measurement values obtained by the second electrode measuring unit when the first electrode driving unit applies the driving voltage to the specific first electrode. The first noise filter may not be applied to some of the measured values that do not correspond to the intersection of at least one first electrode of the above and the extracted at least one second electrode.

According to the above configuration, the touch panel device extracts the measured values corresponding to the plurality of capacitance couplings on the touch panel without applying the first noise filter to the measured values other than the extracted measured values. A first noise filter is applied to the measured values. Therefore, the touch panel device can reduce the processing load of the noise filter.

Further, in the extraction unit, for each of the plurality of first electrodes, whether the number of measured values outside the predetermined range among the plurality of measured values corresponding to the plurality of second electrodes exceeds a predetermined threshold value. Even in a configuration in which it is determined whether or not the extraction unit extracts at least one specific first electrode, which is determined that the number of measured values outside the predetermined range exceeds a predetermined threshold value. good.

According to the above configuration, the extraction unit can extract the first electrode in which noise is superimposed on the output from the plurality of first electrodes based on the measured value of the output of the first electrode.

Further, the extraction unit determines, for each of the plurality of first electrodes, whether or not the sum of the absolute values of the plurality of measured values corresponding to the plurality of second electrodes exceeds a predetermined threshold value. The extraction unit has a configuration in which it is determined that the sum of the absolute values of the plurality of measured values corresponding to the plurality of second electrodes exceeds a predetermined threshold value, and at least one specific first electrode is extracted. You may.

According to the above configuration, the extraction unit can extract the first electrode in which noise is superimposed on the output from the plurality of first electrodes based on the measured value of the output of the first electrode. The extraction unit can also detect the liquid adhesion region.

Further, the extraction unit determines whether or not the total of the plurality of measured values corresponding to the plurality of second electrodes is out of a predetermined range for each of the plurality of first electrodes, and the extraction unit determines whether or not the sum of the plurality of measured values corresponds to the plurality of second electrodes is out of a predetermined range. The configuration may be such that at least one specific first electrode, which is determined to be out of the predetermined range, is extracted from the sum of the plurality of measured values corresponding to the plurality of second electrodes.

According to the above configuration, the extraction unit can extract the first electrode in which noise is superimposed on the output from the plurality of first electrodes based on the measured value of the output of the first electrode. In addition, the extraction unit can exclude the influence of the liquid adhesion region.

Further, the second electrode driving unit may be configured to apply the driving voltage to the plurality of second electrodes at the same time.

According to the above configuration, the processing time of the touch panel device can be shortened as compared with the case where the driving voltage is sequentially applied to the second electrode.

Further, the first electrode driving unit applies the driving voltage to the specific at least one first electrode extracted by the extraction unit, and the first electrode other than the specific at least one first electrode. The drive voltage may not be applied to the above.

According to the above configuration, the processing time of the touch panel device can be shortened as compared with the case where the drive voltage is applied to the first electrode 2 other than the specific at least one first electrode.

Further, the extraction unit determines the strength of noise with respect to the measured value for each of the first electrodes obtained by the first electrode measuring unit when the second electrode driving unit applies the driving voltage. When it is determined that the noise is strong, the first noise filter is applied to the measured value corresponding to the intersection of the extracted at least one specific first electrode and the extracted at least one specific second electrode. When the touch coordinates are specified and it is determined that the noise is weak, a second noise filter is applied to the measured values corresponding to the intersections of the plurality of first electrodes and the plurality of second electrodes, and the touch coordinates are applied. May be configured to specify.

According to the above configuration, when the noise is strong, the touch panel device applies the first noise filter to the extracted measured value. Therefore, the touch panel device can specify the touch coordinates in a short time even when the noise is strong. Further, when the noise is not strong, the touch panel device applies the second noise filter to the measured values corresponding to the plurality of capacitance couplings on the touch panel. Therefore, the touch panel device can make the second noise filter a weaker noise filter than the first noise filter. Therefore, the load of noise filter processing can be reduced and the performance (the number of touch coordinate detections per unit time) can be improved. Further, when the noise is not strong, the touch panel device does not need to measure the output of the second electrode and extract the measured value, so that the processing time of the touch panel device can be shortened.

The control method of the touch panel device according to one aspect of the present invention includes a second electrode driving step of applying a driving voltage to the plurality of second electrodes and a first electrode for measuring outputs from the plurality of first electrodes. Based on the measurement step and the measurement value for each of the first electrodes obtained in the first electrode measurement step when the drive voltage is applied, at least one specific one corresponding to the touch coordinates from the plurality of first electrodes. An extraction step for extracting the first electrode, a first electrode driving step for applying a driving voltage to the plurality of first electrodes, a second electrode measuring step for measuring outputs from the plurality of second electrodes, and the above. Based on the measurement value for each of the second electrodes obtained in the second electrode measurement step when the drive voltage is applied to the specific first electrode, the specific second electrodes correspond to the touch coordinates from the plurality of second electrodes. A first noise filter is extracted from at least one second electrode and has a measured value corresponding to an intersection of the extracted at least one specific first electrode and the extracted at least one specific second electrode. Includes a coordinate specification step that specifies the touch coordinates by multiplying by.

According to one aspect of the present invention, the processing load of the noise filter can be reduced.

It is a block diagram which shows the structure of the touch panel apparatus which concerns on Embodiment 1 and 2 of this invention. It is a figure which shows the typical cross section of the touch panel which concerns on the said embodiment, and the relationship between a drive voltage and a received current. It is a figure which shows the typical cross section of the touch panel when the front cover which concerns on the said Embodiment is touched with a finger, and the relationship between a drive voltage and a received current. It is a figure which shows the region where the noise is superimposed on the output (measured value) in the touch panel when the drive voltage is applied to the 2nd electrode. It is a figure which shows the region where the noise is superimposed on the output (measured value) in the touch panel when the drive voltage is applied to the 1st electrode. It is a figure which shows the area A1 and the area A2 superimposed on the touch panel. It is a flowchart which shows the operation example of the touch panel apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the operation example of the touch panel apparatus which concerns on Embodiment 2 of this invention.

[Embodiment 1]
(Configuration example)
FIG. 1 is a block diagram showing a configuration of a touch panel device 100 according to the present embodiment. The touch panel device 100 includes a touch panel 1, a first electrode input / output unit 4, a second electrode input / output unit 5, an extraction unit 6, a coordinate identification unit 7, and a control unit 8.

The touch panel 1 is a mutual capacitance type touch panel. The touch panel 1 has a plurality of first electrodes 2 provided along an arbitrary axis (X-axis) direction and a plurality of second electrodes provided along an axis (Y-axis) direction perpendicular to the axial direction. 3 and. Each first electrode 2 overlaps and intersects a plurality of second electrodes 3. The first electrode 2 and the second electrode 3 have an electrode structure called, for example, a diamond pattern.

FIG. 2 is a diagram showing a schematic cross section of the touch panel 1 and the relationship between the drive voltage and the received current. FIG. 3 is a diagram showing a schematic cross section of the touch panel 1 when the front cover 13 is touched with a finger, and the relationship between the drive voltage and the received current. In addition, in FIGS. 2 and 3, the first electrode 2 operates as a transmitting electrode, and the second electrode 3 operates as a receiving electrode. The touch panel 1 includes a substrate 11. The substrate 11 may include, for example, a liquid crystal display substrate. Hereinafter, in the touch panel 1, the substrate 11 side is referred to as the lower side, and the front cover 13 side is referred to as the upper side. A plurality of first electrodes 2 are formed on the substrate 11. An insulating layer 12 is formed on the first electrode 2. A plurality of second electrodes 3 are formed on the insulating layer 12. A front cover 13 that comes into contact with a finger when the user operates the touch panel 1 is formed on the plurality of second electrodes 3. Even if the positions of the first electrode 2 and the second electrode 3 are exchanged, there is no difference in the operating principle.

The first electrode 2 is composed of n electrodes numbered from the first electrode 2-1 to the first electrode 2-n. The second electrode 3 is composed of m electrodes numbered from the second electrode 3-1 to the second electrode 3-m. Therefore, n × m capacitance couplings are formed in the intersection region of the n first electrodes 2 and the m second electrodes 3. The first electrode 2 and the second electrode 3 are formed of, for example, an ITO (indium tin oxide) film.

The first electrode input / output unit 4 includes a first electrode driving unit 4a and a first electrode measuring unit 4b. The second electrode input / output unit 5 includes a second electrode driving unit 5a and a second electrode measuring unit 5b. In the touch panel device 100, a first drive mode in which the second electrode input / output unit 5 applies a drive voltage and the second electrode 3 operates as a transmission electrode, and a first electrode input / output unit 4 applies a drive voltage, and the second electrode The 1 electrode 2 may operate as a second drive mode in which the 1 electrode 2 operates as a transmission electrode. That is, when the second electrode drive unit 5a acquires a signal to start the first drive mode, the second electrode drive unit 5a applies a drive voltage to the plurality of second electrodes 3. Further, when the first electrode drive unit 4a acquires a signal to start the second drive mode, the first electrode drive unit 4a applies a drive voltage to the plurality of first electrodes 2. The switching between the first drive mode and the second drive mode may be performed, for example, by switching the connection state of the electric circuit. The drive voltage applied by the drive unit is, for example, a pulse voltage.

In the first drive mode, the first electrode measuring unit 4b measures the outputs from the plurality of first electrodes 2 generated by the driving voltage of the second electrode driving unit 5a. The first electrode measuring unit 4b outputs the measured value to the extraction unit 6. In the second drive mode, the second electrode measuring unit 5b measures the outputs from the plurality of second electrodes 3 generated by the driving voltage of the first electrode driving unit 4a. The second electrode measuring unit 5b outputs the measured value to the coordinate specifying unit 7. The second electrode measuring unit 5b measures, for example, a current or a voltage as a measured value of outputs from the plurality of second electrodes 3.

The extraction unit 6 extracts at least one specific first electrode 2 from the plurality of first electrodes 2 based on the measured values for each of the first electrodes 2 obtained by the first electrode input / output unit 4 in the first drive mode. do. The extraction unit 6 outputs information indicating the extracted first electrode 2 to the coordinate identification unit 7.

The coordinate specifying unit 7 includes a region extraction unit 7a, a noise filter unit 7b, and a coordinate calculation unit 7c. The region extraction unit 7a acquires information indicating the extracted first electrode 2 from the extraction unit 6. The region extraction unit 7a extracts at least one specific second electrode 3 from the plurality of second electrodes 3 based on the measured values for each of the second electrodes 3 obtained by the second electrode input / output unit 5. As a result, the region extraction unit 7a corresponds to the touch coordinates at the intersection (capacitive coupling) between the first electrode 2 extracted by the extraction unit 6 and the second electrode 3 extracted by the region extraction unit 7a. It can be extracted as an area. The noise filter unit 7b has a first noise filter that applies a noise filter to the measured values corresponding to the intersections. The coordinate calculation unit 7c identifies the touch coordinates from the noise-filtered measured values.

The control unit 8 controls the operations of the first electrode input / output unit 4, the second electrode input / output unit 5, the extraction unit 6, and the coordinate specifying unit 7.

The touch panel 1 can be mounted as a sensor including the first electrode 2 and the second electrode 3. The first electrode input / output unit 4, the second electrode input / output unit 5, the extraction unit 6, and the coordinate identification unit 7 can be mounted as controllers by an electric circuit. The sensor and the controller are connected to each other by, for example, a flexible cable.

(Operation example)
FIG. 2 shows the relationship between the drive voltage and the received current. In the three graphs, the horizontal axis is time t and the vertical axis is voltage or current. In the first drive mode, the transmitting electrode is assigned to the second electrode 3 and the receiving electrode is assigned to the first electrode 2. Further, in the second drive mode, the transmitting electrode is assigned to the first electrode 2 and the receiving electrode is assigned to the second electrode 3. The sides of the diamond-patterned electrodes are adjacent to each other between the transmitting electrode and the intersecting receiving electrode. As a result, a capacitance coupling is formed between the transmitting electrode and the receiving electrode. When a square wave pulse-shaped driving voltage is applied to one of the transmitting electrodes, a current flows through the receiving electrode intersecting the transmitting electrode via capacitance coupling. As a result, an electric charge is induced in the receiving electrode, and the potential of the receiving electrode changes. All the transmitting electrodes to which the driving voltage is not applied are connected to a fixed potential. As a result, all the transmission electrodes to which the drive voltage is not applied are in a state of being grounded with respect to alternating current.

FIG. 3 is a diagram showing a schematic cross section of the touch panel 1 and the relationship between the drive voltage and the received current when the front cover 13 is touched with a finger. In the three graphs, the horizontal axis is time t and the vertical axis is voltage or current. When the front cover 13 is touched with a finger, the electric lines of force flowing from the transmitting electrode to the receiving electrode are absorbed by the finger. As a result, the current flowing through the receiving electrode becomes smaller according to the drive voltage, and the change in the potential of the receiving electrode becomes smaller. By detecting the amount of this displacement becoming smaller, it is possible to measure the amount of decrease in capacitance (mutual capacitance) between the transmitting electrode and the receiving electrode.

The external noise input from the sensor includes, for example, noise coming from space due to electric discharge, fluorescent lamp, radio wave, etc. (referred to as external noise A), and noise injected from the touched object (human body or touch pen) (referred to as external noise A). External noise B), etc. These external noises do not cause a change in the mutual capacitance detected by the mutual capacitance type touch panel, but are detected by the measuring unit as a noise current flowing through the receiving electrode. Therefore, in order to extract the current value corresponding to the drive voltage from the measured value in which the current corresponding to the drive voltage (pulse voltage) and the noise current are superimposed, the filter technique must be used. Noise can shift the measured value significantly to the positive or negative side at random.

When the noise is particularly strong, the touch panel device needs to apply a strong noise filter. However, for example, if a strong noise filter is applied to the outputs of all the receiving electrodes, the performance of the touch panel device is significantly deteriorated. The touch panel device 100 according to the present embodiment extracts an output to which a noise filter should be applied from the outputs of a plurality of receiving electrodes, and applies a noise filter to the extracted output. Therefore, the processing load of the noise filter can be reduced. Therefore, the touch panel device 100 can apply the noise filter in a short time and specify the touch coordinates even when the noise superimposed on the output of the receiving electrode is strong.

FIG. 4 is a diagram showing a region in which noise is superimposed on the output (measured value) of the touch panel 1 when a driving voltage is applied to the second electrode 3. Since the external noise B is noise injected from the touched object, when a driving voltage is applied to the second electrode 3 (transmission electrode), the output of the first electrode 2 (reception electrode) near the touch coordinates is external. Noise B is superimposed. Therefore, the touch coordinates exist at least in the region A1 corresponding to the first electrode 2 on which the external noise is superimposed. When a drive voltage is applied to the second electrode 3, the touch panel device 100 extracts the first electrode 2 in which noise is superimposed on the output as the first electrode 2 corresponding to the touch coordinates.

FIG. 5 is a diagram showing a region in which noise is superimposed on the output (measured value) of the touch panel 1 when a driving voltage is applied to the first electrode 2. Since the external noise B is the noise injected from the touched object, when the first electrode 2 (transmission electrode) is applied, the external noise B is output to the output of the second electrode 3 (reception electrode) near the touch coordinates. Superimpose. Therefore, the touch coordinates exist at least in the region A2 corresponding to the second electrode 3 on which the external noise is superimposed. When a drive voltage is applied to the first electrode 2, the touch panel device 100 extracts the second electrode 3 on which noise is superimposed on the output as the second electrode 3 corresponding to the touch coordinates.

FIG. 6 is a diagram showing the area A1 and the area A2 superimposed on the touch panel 1. Since the touch coordinates exist in the area A1 and the area A2, the touch coordinates exist at least in the area A3 where the area A1 and the area A2 intersect. The touch panel device 100 applies a noise filter to, for example, the measured values corresponding to the capacitance coupling in the region A3. In this way, by applying the application to the second electrode 3 and the application to the first electrode 2 (application of the driving voltage in both directions), the region corresponding to the touch coordinates can be limited.

The noises considered here are all external noises, and the noises generated inside the touch panel device are smaller than the external noises and can be ignored.

FIG. 7 is a flowchart showing the operation of the touch panel device 100 according to the embodiment of the present invention. An operation example in which the touch panel device 100 applies the first noise filter to the extracted measured values will be described with reference to FIG. 7.

The control unit 8 outputs a signal to zero (initialize) all the stored measured values to the extraction unit 6 and the coordinate identification unit 7. Similarly, the control unit 8 outputs a signal to the effect that all determinations are initialized to the extraction unit 6 and the region extraction unit 7a of the coordinate identification unit 7.

Next, the control unit 8 outputs a signal to start the first drive mode to the second electrode drive unit 5a. When the second electrode drive unit 5a acquires a signal to start the first drive mode, the second electrode drive unit 5a applies a drive voltage to the plurality of second electrodes 3 (S1). The first electrode measuring unit 4b measures the outputs from the plurality of first electrodes 2 generated by the driving voltage of the second electrode driving unit 5a (S2). The first electrode measuring unit 4b outputs the measured value for each first electrode 2 to the extraction unit 6. The extraction unit 6 acquires and stores the measured values for each of the plurality of first electrodes 2 from the first electrode measuring unit 4b.

In the first drive mode, the second electrode drive unit 5a may apply a drive voltage to the second electrode 3-1, the second electrode 3-2, ... The second electrode 3-m in this order. good. Here, when the second electrode driving unit 5a applies a driving voltage to, for example, the second electrode 3-1 the first electrode measuring unit 4b has the second electrode 3-1 and n first electrodes. N measurement values corresponding to n capacitance couplings intersecting with 2 are measured. Further, when a driving voltage is applied to the second electrode 3-2, ... The second electrode 3-m, n measurement values corresponding to n capacitance couplings are measured in the same manner. .. Therefore, when the second electrode driving unit 5a applies a driving voltage to the m second electrodes 3 in order, the extraction unit 6 measures n × m corresponding to n × m capacitance coupling. The value will be memorized.

Next, the extraction unit 6 determines whether or not noise is superimposed on the measured values for each of the plurality of first electrodes 2 by, for example, the determination methods 1 to 3 described later. The extraction unit 6 extracts the first electrode 2 corresponding to the measured value determined to have the noise superimposed as the first electrode 2 corresponding to the touch coordinates (S3). The extraction unit 6 outputs information indicating the first electrode 2 extracted by the extraction unit 6 to the region extraction unit 7a of the coordinate identification unit 7.

(Judgment method 1)
In the extraction unit 6, for each of the plurality of first electrodes 2, the number of measured values outside the predetermined range among the plurality of (m) measured values corresponding to the plurality of (m) second electrodes 3 is , Determine whether or not a predetermined threshold value has been exceeded. The extraction unit 6 extracts at least one specific first electrode 2 for which it is determined that the number of measured values outside the predetermined range exceeds a predetermined threshold value as the first electrode 2 corresponding to the touch coordinates. do. The predetermined range may be, for example, a range in which the measured value is + S1 to −S1. The predetermined threshold value may be, for example, zero. That is, the extraction unit 6 may determine that noise is superimposed when at least one of the m measured values is out of the predetermined range.

(Judgment method 2)
In the extraction unit 6, for each of the plurality of first electrodes 2, the sum of the absolute values of the plurality of (m) measured values corresponding to the plurality of (m) second electrodes 3 exceeds a predetermined threshold value. Judge whether or not. The extraction unit 6 touch coordinates at least one specific first electrode 2 for which it is determined that the sum of the absolute values of the plurality of measured values corresponding to the plurality of second electrodes 3 exceeds a predetermined threshold value. Is extracted as the first electrode 2 corresponding to.

Further, when the liquid is attached to the touch panel, if the total of the measured values is taken, the change in the measured value caused by the adhesion of the liquid is offset. On the other hand, in the determination method in the determination method 2, since the total of the absolute values of the measured values is taken, the coordinate specifying unit 7 can also specify the liquid adhesion region.

(Judgment method 3)
The extraction unit 6 determines whether or not the total of the plurality of (m) measured values corresponding to the plurality of (m) second electrodes 3 is out of the predetermined range for each of the plurality of first electrodes 2. To judge. The predetermined range may be, for example, a range of measured values from + S2 to −S2. The extraction unit 6 determines that the sum of the plurality of measured values corresponding to the plurality of second electrodes 3 is out of a predetermined range, and determines that at least one specific first electrode 2 corresponds to the touch coordinates. Extract as electrode 2.

When the extraction unit 6 determines whether or not noise is superimposed by the determination method 3, the second electrode drive unit 5a receives the second electrode 3-1 and the second electrode 3-2 in the first drive mode. ... The drive voltage may be applied to the second electrode 3-m at the same time. Here, the output measured by the first electrode measuring unit 4b, for example, from the first electrode 2-1 is the capacitance of m at which the m second electrodes 3 and the first electrode 2-1 intersect. It is the sum of the outputs produced by the coupling. Therefore, when the second electrode driving unit 5a simultaneously applies a driving voltage to the m second electrodes 3, the extraction unit 6 stores n measured values corresponding to the n first electrodes 2. It will be. With the above configuration, the processing time of the touch panel device 100 can be shortened as compared with the case where the driving voltage is sequentially applied to the second electrode 3.

Next, the control unit 8 outputs a signal to start the second drive mode to the first electrode drive unit 4a. When the first electrode drive unit 4a acquires a signal to start the second drive mode, the first electrode drive unit 4a applies a drive voltage to the plurality of first electrodes 2 (S4). The second electrode measuring unit 5b measures the outputs from the plurality of second electrodes 3 generated by the driving voltage of the first electrode driving unit 4a (S5). The second electrode measuring unit 5b outputs the measured value for each of the second electrodes 3 to the coordinate specifying unit 7. The coordinate specifying unit 7 acquires and stores the measured values for each of the plurality of second electrodes 3 from the second electrode measuring unit 5b. In the second drive mode, as in the first drive mode, the first electrode drive unit 4a relates to the first electrode 2-1 and the first electrode 2-2, ... First electrode 2-n. The drive voltage may be applied in order.

Next, the region extraction unit 7a acquires information indicating the first electrode 2 extracted by the extraction unit 6 from the extraction unit 6. The region extraction unit 7a determines whether or not noise is superimposed on the measured values for each of the plurality of second electrodes 3 based on the measured values corresponding to the first electrode 2 extracted by the extraction unit 6. do. The region extraction unit 7a extracts the second electrode 3 corresponding to the measured value determined to have the noise superimposed as the second electrode 3 corresponding to the touch coordinates (S6). The region extraction unit 7a sets the intersection of the first electrode 2 extracted by the extraction unit 6 and the second electrode 3 extracted by the region extraction unit 7a as a region corresponding to the touch coordinates (for example, the region A3 including the touch coordinates). ) Can be extracted. The region extraction unit 7a outputs information about the extracted intersections to the noise filter unit 7b.

The determination method by the region extraction unit 7a may be the same as the determination methods 1 to 3 described above in the extraction unit 6. When the determination method by the region extraction unit 7a is the same as the determination method 3 described above, in the second drive mode, the first electrode drive unit 4a has the first electrode 2-1 and the first electrode 2-2. A drive voltage may be applied to the first electrode 2-n at the same time. In this case, in the first drive mode, the second electrode drive unit 5a individually applies a drive voltage to the second electrode 3-1 and the second electrode 3-2, ... The second electrode 3-m.

Next, the noise filter unit 7b applies the first noise filter to a plurality of measured values corresponding to the plurality of intersections (intersections included in the region A3) extracted by the region extraction unit 7a (S7). The noise filter unit 7b outputs a plurality of measured values to which the first noise filter is applied to the coordinate calculation unit 7c. The coordinate calculation unit 7c identifies the touch coordinates from the plurality of filtered (noise-removed) measured values (S8). For example, the coordinate calculation unit 7c specifies as touch coordinates the intersections included in the region A3 in which the current flowing through the receiving electrode or the change in the potential of the receiving electrode is equal to or less than a predetermined threshold value.

FIGS. 4 to 6 schematically show an operation example in which the extraction unit 6 and the region extraction unit 7a extract the measured values to which the first noise filter is applied. Here, the capacitance coupling formed in the intersection region of the first electrode 2-p and the second electrode 3-q is referred to as a capacitance coupling (p, q). However, p and q are arbitrary integers that satisfy 1 ≦ p ≦ n and 1 ≦ q ≦ m. Further, in the first drive mode, the measured value of the output generated by the capacitance coupling (p, q) is defined as the first measured value (p, q). Similarly, in the second drive mode, the measured value of the output generated by the capacitance coupling (p, q) is defined as the second measured value (p, q).

First, the extraction unit 6 superimposes noise on the output from the first electrode 2-p based on a plurality of measured values output from the first electrode 2-p by sequentially applying m second electrodes 3. Judge whether or not it is done. Here, the plurality of measured values output are the first measured value (p, 1), the first measured value (p, 2), ... The first measured value (p, m). For example, when the extraction unit 6 determines that noise is superimposed on the output from the first electrode 2 from the first electrode 2-i1 to the first electrode 2-i2, the first electrode 2-i1 to the first electrode 6 The first electrode 2 up to the electrodes 2-i2 is extracted as the first electrode 2 corresponding to the touch coordinates. That is, the extraction unit 6 extracts the region A1 surrounded by the first electrode 2-i1 and the first electrode 2-i2 from the touch panel 1.

Next, the region extraction unit 7a is based on a plurality of measured values output from the second electrode 3-q by sequentially applying the first electrode 2 from the first electrode 2-i1 to the first electrode 2-i2. , It is determined whether or not noise is superimposed on the output from the second electrode 3-q. Here, the plurality of measured values output are from the second measured value (i1, q) to the second measured value (i2, q). For example, when the region extraction unit 7a determines that noise is superimposed on the output from the second electrode 3 from the second electrode 3-j1 to the second electrode 3-j2, the second electrode 3-j1 to the second electrode 7a The second electrode 3 up to the two electrodes 3-j2 is extracted as the second electrode 3 corresponding to the touch coordinates. That is, the region extraction unit 7a extracts the region A2 surrounded by the second electrode 3-j1 and the second electrode 3-j2 from the touch panel 1.

Next, the region extraction unit 7a includes the first electrode 2 from the first electrode 2-i1 to the first electrode 2-i2 and the second electrode 3 from the second electrode 3-j1 to the second electrode 3-j2. Extract the intersection of. That is, the area extraction unit 7a extracts the area A3 where the area A1 and the area A2 intersect as the area corresponding to the touch area. The area extraction unit 7a may extract the area including the area A3 as the area corresponding to the touch area. The noise filter unit 7b applies the first noise filter to the measured value corresponding to the touch region (for example, region A3). That is, the noise filter unit 7b includes the first electrode 2 from the first electrode 2-i1 to the first electrode 2-i2 and the second electrode 3 from the second electrode 3-j1 to the second electrode 3-j2. The first noise filter is applied to a plurality of measured values corresponding to the intersections.

By applying the first noise filter, a plurality of noise-removed measured values corresponding to the intersections included in the region A3 can be obtained. The coordinate calculation unit 7c identifies an intersection corresponding to the touch coordinate among the intersections included in the region A3 by using a plurality of measured values from which noise has been removed.

In the present embodiment, the touch panel device 100 is a first noise filter with respect to the measured value for each first electrode 2 obtained by the first electrode measuring unit 4b when the second electrode driving unit 5a applies a driving voltage. Does not apply. Further, the touch panel device 100 extracts from a plurality of measured values obtained by the second electrode measuring unit 5b when the first electrode driving unit 4a applies a driving voltage to at least one specific first electrode 2. For some measured values that do not correspond to the intersection of the specified at least one first electrode and the extracted specific at least one second electrode (for example, the measured values corresponding to a region other than the region A3). The first noise filter is not applied. That is, the touch panel device 100 is an extracted measurement from the measured values corresponding to a plurality of capacitance couplings on the touch panel 1 (n × m measured values corresponding to n × m capacitance couplings). The first noise filter is not applied to the measured values other than the values, but the first noise filter is applied to the extracted measured values. With the above configuration, the touch panel device 100 can reduce the processing load of the noise filter and apply a strong noise filter that opposes the strong noise to an appropriate range in a short time.

(Modification example 1)
In the second drive mode, the first electrode drive unit 4a applies a drive voltage to at least one specific first electrode 2 extracted by the extraction unit 6, and other than the specific at least one first electrode 2. It is not necessary to apply a driving voltage to the first electrode 2. With the above configuration, the processing time of the touch panel device 100 can be shortened as compared with the case where the drive voltage is applied to the first electrode 2 other than the specific at least one first electrode 2.

The touch panel is typically landscape. That is, in the mutual capacitance type touch panel, the number of horizontal electrodes is smaller than the number of vertical electrodes. Further, the touch panel device typically operates with the horizontal electrode as the transmitting electrode and the vertical electrode as the receiving electrode. By using a smaller number of horizontal electrodes (transmission electrodes) to which the drive voltage is applied, the processing time of the touch panel device can be shortened.

In the case of the first modification, for example, the touch panel device 100 applies a drive voltage to m second electrodes 3 in the first drive mode, while a part of the first electrodes in the second drive mode. A drive voltage is applied to 2. Therefore, in the touch panel device 100, in order to reduce the operation of applying the drive voltage, it is preferable that the second electrode 3 has a smaller number of horizontal electrodes. With the above configuration, the processing time of the touch panel device 100 can be shortened.

[Embodiment 2]
Other embodiments of the present invention will be described below. For convenience of explanation, the members having the same functions as the members described in the above-described embodiment are designated by the same reference numerals, and the description thereof will not be repeated.

(Configuration example)
The noise filter unit 7b has a second noise filter that applies a noise filter to n × m measured values corresponding to the intersections of the plurality of first electrodes 2 and the plurality of second electrodes 3.

(Operation example)
FIG. 8 is a flowchart showing the operation of the touch panel device 100 according to the second embodiment of the present invention. An operation example in which the touch panel device 100 determines the strength of noise by the second noise filter will be described with reference to FIG.

S1 and S2 are the same as those in the first embodiment. It is preferable that the second electrode driving unit 5a applies a driving voltage to the second electrode 3-1, the second electrode 3-2, ... The second electrode 3-m in this order. That is, the extraction unit 6 stores n × m measured values corresponding to n × m capacitance coupling.

Next, the extraction unit 6 determines whether or not the noise is strong (S10). Specifically, in the extraction unit 6, when the number of measured values outside the predetermined range exceeds a predetermined threshold value among the n × m measured values corresponding to the n × m capacitance coupling. In addition, it may be determined that the noise is strong. The predetermined range may be, for example, a range of measured values from + S3 to −S3. If the extraction unit 6 determines that the noise is strong (YES in S10), the process proceeds to S3. If the extraction unit 6 determines that the noise is not strong (NO in S10), the process proceeds to S11. S3 to S8 are the same as those in the first embodiment.

When the extraction unit 6 determines that the noise is not strong (NO in S10), the extraction unit 6 outputs n × m measured values corresponding to n × m capacitance coupling to the coordinate identification unit 7. do. The noise filter unit 7b acquires n × m measured values corresponding to n × m capacitance coupling from the extraction unit 6, and applies a second noise filter to the n × m measured values. (S11). The coordinate calculation unit 7c specifies the touch coordinates from the filtered n × m measured values (S12). In this case, the measurement in the second drive mode can be omitted.

When the noise superimposed on the output of the receiving electrode is strong, the touch panel device needs to apply a strong noise filter. However, for example, if a strong noise filter is applied to the signals (measured values of n × m) of the entire touch panel, the performance of the touch panel device is significantly deteriorated. When the noise is strong, the touch panel device 100 applies the first noise filter to the extracted measured value. Therefore, the touch panel device 100 can specify the touch coordinates in a short time even when the noise is strong. Further, when the noise is not strong, the touch panel device 100 applies a second noise filter to the measured values (n × m measured values) corresponding to the plurality of capacitance couplings on the touch panel. .. Therefore, the touch panel device 100 can make the second noise filter a weaker noise filter than the first noise filter. Therefore, the load of noise filter processing can be reduced and the performance (the number of touch coordinate detections per unit time) can be improved. Further, when the noise is not strong, the touch panel device 100 does not need to measure the output of the second electrode 3 and extract the measured value, so that the processing time of the touch panel device 100 can be shortened.

(Modification 2)
The touch panel device 100 may omit the operations of S1 and S2. Here, the touch panel device 100 determines whether or not the noise is strong by referring to the past data in S10. For example, the extraction unit 6 calculates the variance of the plurality of (m) measured values corresponding to the plurality of (m) second electrodes 3 for each of the plurality of first electrodes 2 with respect to the past measured values. .. When the number of the dispersions of each of the plurality of first electrodes 2 exceeding the predetermined first threshold value exceeds the predetermined second threshold value, the extraction unit 6 determines that the noise is strong. As the extraction unit 6, for example, the one obtained by averaging the variances of the measured values for the last five times may be used.

If the extraction unit 6 determines that the noise is strong (YES in S10), the process proceeds to S1. When the extraction unit 6 determines that the noise is not strong (NO in S10), the process proceeds to S11 via S4 and S5.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1 Touch panel 2 1st electrode 3 2nd electrode 4 1st electrode input / output unit 4a 1st electrode drive unit 4b 1st electrode measurement unit 5 2nd electrode input / output unit 5a 2nd electrode drive unit 5b 2nd electrode measurement unit 6 Extraction Unit 7 Coordinate identification unit 7a Area extraction unit 7b Noise filter unit 7c Coordinate calculation unit 8 Control unit 11 Board 12 Insulation layer 13 Front cover 100 Touch panel device

Claims (9)

A plurality of first electrodes and a plurality of second electrodes intersecting the plurality of first electrodes are provided, and a plurality of capacitance couplings are formed at the intersections of the plurality of first electrodes and the plurality of second electrodes. Capacitive touch panel and
A second electrode drive unit that applies a drive voltage to the plurality of second electrodes,
A first electrode measuring unit that measures outputs from the plurality of first electrodes,
Based on the measured value for each of the first electrodes obtained by the first electrode measuring unit when the second electrode driving unit applies the driving voltage, the specific first electrode corresponds to the touch coordinates from the plurality of first electrodes. An extraction unit that extracts at least one first electrode,
A first electrode driving unit that applies a driving voltage to the plurality of first electrodes,
A second electrode measuring unit that measures the output from the plurality of second electrodes,
The plurality of second electrodes are based on the measured values for each of the second electrodes obtained by the second electrode measuring unit when the first electrode driving unit applies the driving voltage to the specific first electrode. A specific at least one second electrode corresponding to the touch coordinates is extracted from, and a measurement corresponding to the intersection of the extracted specific at least one first electrode and the extracted specific at least one second electrode is obtained. A touch panel device including a coordinate specifying unit that applies a first noise filter to a value and specifies touch coordinates. The extraction unit does not apply the first noise filter to the measured values for each of the first electrodes obtained by the first electrode measuring unit when the second electrode driving unit applies the driving voltage.
The coordinate specifying unit is the identification extracted from a plurality of measurement values obtained by the second electrode measuring unit when the first electrode driving unit applies the driving voltage to the specific first electrode. 1. The first noise filter is not applied to some measured values that do not correspond to the intersection of at least one first electrode of the above and the extracted at least one second electrode. The touch electrode device described in 1. The extraction unit determines whether or not the number of measured values outside the predetermined range exceeds a predetermined threshold value among the plurality of measured values corresponding to the plurality of second electrodes for each of the plurality of first electrodes. Judging,
The extraction unit according to claim 1 or 2, wherein the extraction unit extracts at least one specific first electrode for which it is determined that the number of measured values outside the predetermined range exceeds a predetermined threshold value. The described touch panel device. The extraction unit determines, for each of the plurality of first electrodes, whether or not the sum of the absolute values of the plurality of measured values corresponding to the plurality of second electrodes exceeds a predetermined threshold value.
The extraction unit extracts at least one specific first electrode for which it is determined that the sum of the absolute values of the plurality of measured values corresponding to the plurality of second electrodes exceeds a predetermined threshold value. The touch panel device according to claim 1 or 2. The extraction unit determines, for each of the plurality of first electrodes, whether or not the sum of the plurality of measured values corresponding to the plurality of second electrodes is out of a predetermined range.
The extraction unit is characterized in that it extracts at least one specific first electrode for which it is determined that the sum of a plurality of measured values corresponding to the plurality of second electrodes is out of a predetermined range. The touch panel device according to 1 or 2. The touch panel device according to claim 5, wherein the second electrode driving unit applies the driving voltage to the plurality of second electrodes at the same time. The first electrode driving unit applies the driving voltage to the specific at least one first electrode extracted by the extraction unit, and applies the driving voltage to the first electrodes other than the specific at least one first electrode. The touch panel device according to any one of claims 1 to 6, wherein the drive voltage is not applied. The extraction unit determines the strength of noise with respect to the measured value for each of the first electrodes obtained by the first electrode measuring unit when the second electrode driving unit applies the driving voltage.
If it is determined that the noise is strong, the first noise filter is applied to the measured value corresponding to the intersection of the extracted at least one specific first electrode and the extracted at least one specific second electrode. Multiply, identify touch coordinates,
When it is determined that the noise is weak, a second noise filter is applied to the measured values corresponding to the intersections of the plurality of first electrodes and the plurality of second electrodes, and the touch coordinates are specified. The touch panel device according to any one of claims 1 to 7. A plurality of first electrodes and a plurality of second electrodes intersecting the plurality of first electrodes are provided, and a plurality of capacitance bonds are formed at the intersections of the plurality of first electrodes and the plurality of second electrodes. It is a control method of a touch panel device equipped with a touch panel by a capacitance method.
A second electrode drive step in which a drive voltage is applied to the plurality of second electrodes,
A first electrode measurement step for measuring the output from the plurality of first electrodes, and
Based on the measured value for each of the first electrodes obtained in the first electrode measuring step when the driving voltage is applied, at least one specific first electrode corresponding to the touch coordinates is selected from the plurality of first electrodes. Extraction steps to extract and
A first electrode drive step in which a drive voltage is applied to the plurality of first electrodes,
Measurement for each of the second electrodes obtained in the second electrode measurement step for measuring the outputs from the plurality of second electrodes and the second electrode measurement step when the drive voltage is applied to the specific first electrode. Based on the values, at least one specific second electrode corresponding to the touch coordinate is extracted from the plurality of second electrodes, and the extracted at least one specific first electrode and the extracted specific at least one are extracted. A control method for a touch panel device, which comprises applying a first noise filter to a measured value corresponding to an intersection with two second electrodes and including a coordinate specifying step for specifying touch coordinates.

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