JP2011059793A - Touch position detection device, information input system, touch position detection method and touch position detection program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect touch positions in multi-touch on a touch panel with high accuracy. <P>SOLUTION: The touch position detection device is provided in a touch panel on a matrix having row electrodes and column electrodes, and includes: a column electrode drive circuit 8 applying an input signal to the adjacent column electrodes from one end side in the opposite direction different from each other; a position detection processing part 21a detecting an output signal from the row electrode, comparing the output signal with a preset first threshold value, holding a detected position as first touch position information when it is larger than the threshold value, comparing the magnitude of the output signal and a second threshold value smaller than the first threshold value, and deciding a detected position as second touch position information when it is larger than the second threshold value; and a coordinate arithmetic circuit 11a determining a logical sum of coordinates decided as touch of the first touch position information and coordinates decided as touch of the second touch position information adjacent to the coordinates in a row direction as final touch position information indicating coordinates decided as touch. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a matrix type touch panel using a resistance film for coordinate input, and more particularly to an apparatus for detecting multiple touches on a touch panel.

  For example, a touch panel that detects position information of an object that contacts a display surface of a display device such as a liquid crystal display is widely used as one of input devices. As a touch panel system, there is a resistive film system using a resistive film such as ITO (Indium Tin Oxide). Resistive touch panels are most commonly used among touch panels because of their simple structure and low cost.

There are two types of resistive touch panels: analog and matrix. The analog type touch panel has a structure in which a resistive film is formed in a planar shape on each of the pressing side substrate and the non-pressing side substrate, and the pressing side substrate and the non-pressing side substrate are arranged to face each other via a spacer.
For example, a voltage is applied in the X direction of the resistance film of the pressing side substrate, and the voltage divided by the resistance film of the pressing side substrate according to the touch position is read by the non-pressing side substrate.
Next, a voltage is applied in the Y direction of the resistance film of the non-pressing side substrate, and the voltage divided by the resistance film of the non-pressing side substrate according to the touch position by the resistance film of the pressing side substrate is read by the pressing side substrate. . Based on the read voltages in the X and Y directions, the coordinates in the X direction and the coordinates in the Y direction are calculated.
From such a processing method, when two or more points are touched simultaneously with an analog touch panel (multiple touch), the intermediate point is calculated as a touch position, so that it is not possible to handle multiple touches. there were.

On the other hand, in the matrix type touch panel, the resistive film in the analog type touch panel is formed in a strip shape, and the formation direction is orthogonal between the pressing side substrate and the non-pressing side substrate.
For example, coordinates are calculated according to the magnitude of the voltage output to the strip-shaped resistance film of the non-pressing side substrate while sequentially applying a voltage to the strip-shaped resistance film of the pressing-side substrate. In other words, since the matrix type touch panel can detect the touch position in units of the strip-shaped resistive film of each substrate, it can recognize two or more simultaneous touches and can support multiple touches. it can.

Here, the structure of the matrix type touch panel and the detection processing method will be described. As shown in FIG. 1, the matrix-type touch panel is mainly composed of a first substrate 1 and a second substrate 2 which are arranged to face each other via a spacer (not shown). A plurality of row electrodes 3 made of a transparent conductive material such as ITO are formed on the first substrate 1, and a plurality of column electrodes 4 made of the same transparent conductive material are formed on the second substrate 2.
When touching with the finger or the like from the second substrate 2 side, the row electrode 3 and the column electrode 4 in the vicinity of the touch point come into contact at their intersection. By detecting this contact, the touch point is recognized.
In FIG. 1, a voltage signal is applied to the column electrode C1 of the first column, and a change in voltage of all the row electrodes 3 is detected to determine which row of the first column is in contact. The touch position is calculated by performing this operation for all the column electrodes 4.
Here, when a signal is applied to a certain column electrode 4, the other column electrode 4 is set to high impedance, and the row electrode 3 other than the row electrode 3 to be detected is also connected to the GND to thereby connect the row electrode 3. Since each of the intersections of the column electrodes 4 can detect a contact independently, it can cope with multiple touches.

However, the matrix type touch panel as described above has a disadvantage that a phenomenon called masking occurs at the time of multiple touches and the accuracy of touch detection is lowered.
Here, this masking will be described with reference to FIG.
When multiple touches occur due to a touch near the end on the signal input side (touch P1 in FIG. 2) and a touch near the other end (touch P2 in FIG. 2) in the same column electrode 4, the touch P1 intersects. Since the voltage of the signal applied by the row electrode 3 is divided, the voltage detected by the row electrode 3 that intersects at the touch P2 becomes very small.
Here, the graph (FIG. 3) which shows the change of the voltage detected by the touch P2 by the presence or absence of the touch P1 is shown. In FIG. 3, the horizontal axis of the graph represents the pressure of the touch, and the vertical axis represents the potential detected by the row electrode.
At this time, the potential decreases due to the presence of the touch P1. When the touch pressure is T and the touch P1 is not present, the detected potential is greater than the threshold value, and therefore the touch P2 is recognized as a touch.
However, when the touch P1 is present, the detected potential is smaller than the threshold value, so the touch P2 is not recognized as a touch and masking occurs.

As a related technique for this, a technique is disclosed in which a row electrode and a column electrode are engaged with each other in order to prevent occurrence of masking due to a decrease in detection signal at the time of multiple touch of a matrix type touch panel (Patent Document 1). ).
In Patent Document 1, since the electrodes are engaged with each other, signal inputs to two adjacent electrodes are opposite to each other.
For this reason, for example, even if there is an electrode that cannot be detected by masking on the touch surface, there is no other touch that causes masking on the signal input side of the electrode adjacent to the electrode, so that the touch can be detected.

As another related technique for suppressing the occurrence of masking, a technique for changing a threshold value for digitally converting a detection signal is disclosed (Patent Document 2).
As described above, masking occurs because the detection signal becomes smaller due to the influence of another touch on the signal input side than the touch position to be masked. Therefore, the threshold value for digital conversion for determining the presence / absence of a touch is reduced so that a detection signal that is reduced from an electrode far from the signal input side is recognized as a touch. Thereby, even the touch position where the signal is reduced by masking is recognized as a touch, and the occurrence of masking can be suppressed.

JP-T-2004-523833 Special table 2007-527061 gazette

However, in the related art disclosed in Patent Document 1, touch recognition can be performed even when masking occurs, but the electrodes for detecting signals corresponding to the touch are halved, and the resolution of touch detection is reduced. There is an inconvenience.
Moreover, in the related art of the above-mentioned patent document 2, when the touch panel is deteriorated, it reacts to a small threshold value even at a position where it is not actually touched, which may cause a problem of erroneous recognition as a touch. That is, there is a disadvantage that the detection accuracy of the touch panel is lowered by applying the above-described means.

[Object of invention]
The present invention provides a position detection device, an information input system, a touch position detection method, and a touch position detection program that improve the inconveniences of the related techniques and suppress the occurrence of masking and perform detection corresponding to multiple touches with high accuracy. Its purpose is to provide.

  In order to achieve the above object, a touch position detection device according to the present invention includes a row electrode formed in parallel along a preset row direction and a column formed along a column direction intersecting the row direction. A touch panel in which electrodes are arranged opposite to each other, an external terminal that applies an input signal to the adjacent column electrode in a reverse direction from different one ends of the column electrodes, and the input by contact of the column electrode and the row electrode A touch position detection device comprising: a touch position detection unit that detects a position where an external pressure is applied to the touch panel based on an output signal output from the row electrode in response to a signal, the touch position detection unit Sequentially scans and drives the column electrode and the row electrode, and detects an output signal from the row electrode in synchronization with the timing of applying the input signal to the column electrode. The output signal detecting means compares the magnitude of the output signal with a first threshold value set in advance and determines that the touch is greater than the first threshold value and indicates the position of the touch. A first touch position determining means for holding information as the first touch position information, and comparing a magnitude of the output signal with a second threshold value smaller than the preset first threshold value and A second touch position determining means for determining that the output signal is larger than the second threshold value as a touch and holding information indicating the position of the touch as second touch position information; and the first touch. Final touch position in which the logical sum of the coordinates determined as touch in the position information and the coordinates determined as touch in the second touch position information adjacent to the coordinates in the row direction is the coordinate determined as touch Has taken a configuration in which a final touch position determining means for determining a distribution.

  In the touch position detection method according to the present invention, a row electrode formed in parallel along a preset row direction and a column electrode formed along a column direction intersecting the row direction are arranged to face each other. A touch panel, an external terminal for applying an input signal in the opposite direction from the different one end side of the column electrodes to the adjacent column electrode, and the input signal corresponding to the input signal by contact of the column electrode and the row electrode A touch position detection device including a touch position detection unit that obtains an output signal output from a row electrode, wherein the touch position detection method detects a position to which an external pressure is applied on the touch panel. The electrode and the row electrode are sequentially scanned and driven, and an output signal from the row electrode is detected in synchronization with a timing at which the input signal is applied to the column electrode, and the output The size of the signal is compared with a first threshold value set in advance, and when it is larger than the first threshold value, it is determined as a touch, and information indicating the position of the touch is held as first touch position information A case in which the magnitude of the output signal is compared with a preset second threshold value smaller than the first threshold value and the magnitude of the output signal is greater than the second threshold value. Information that is determined to be a touch and indicates the position of the touch is stored as second touch position information, and the coordinates determined to be a touch in the first touch position information and the second touch position adjacent to the coordinates in the row direction. It is characterized in that final touch position information is determined using a logical sum of coordinates determined as touches among the information as coordinates determined as touches.

  In the touch position detection program according to the present invention, a row electrode formed in parallel along a preset row direction and a column electrode formed along a column direction intersecting the row direction are arranged to face each other. A touch panel, an external terminal for applying an input signal in the opposite direction from the different one end side of the column electrodes to the adjacent column electrode, and the input signal corresponding to the input signal by contact of the column electrode and the row electrode A touch position detection device including a touch position detection unit that obtains an output signal output from a row electrode, and a touch position detection program for detecting a position to which an external pressure is applied on the touch panel, The column electrode and the row electrode are sequentially scanned and driven, and an output signal from the row electrode is synchronized with the timing of applying the input signal to the column electrode. The output signal detection function to be output and the magnitude of the output signal are compared with a first threshold value set in advance, and when it is larger than the first threshold value, it is determined as a touch and the position of the touch is determined. A first touch position determination function that performs a process of holding information indicating the first touch position information, and a magnitude of the output signal compared with a preset second threshold value smaller than the first threshold value And a second touch position determination function that performs a process of determining that the output signal is larger than the second threshold value as a touch and using information indicating the position of the touch as second touch position information; The coordinates of the first touch position information determined as touch and the logical sum of the coordinates determined as touch among the coordinates of the second touch position information adjacent to the coordinates in the row direction To do And a final touch position determination function of determining the touch location information, is characterized by causing a computer to execute set in the touch position detection unit.

  Since the present invention is configured and functions as described above, according to this, the touch is determined based on the first threshold value and the second threshold value, and finally the touch position information at each threshold value is used. Touch position detection device and information input system capable of detecting multiple touches with high accuracy without degrading detection accuracy even when masking occurs due to the configuration for determining accurate touch position information , A touch position detection method and a touch position detection program can be provided.

It is explanatory drawing which shows the structure of a resistive touch panel matrix type touch panel. It is explanatory drawing which shows the masking state in a resistance-film-type matrix type touch panel. FIG. 3 is an explanatory diagram showing a change in detection potential when masking occurs in the resistive film type matrix type touch panel of FIG. 2. It is a schematic block diagram which shows one Embodiment in the touch position detection apparatus by this invention. It is explanatory drawing which shows the structure of the touch panel in the touch position detection apparatus disclosed in FIG. 5 is a timing chart showing the timing of detection processing in the touch position detection device disclosed in FIG. 4. 6 is a flowchart showing operation steps of a processing function of a coordinate calculation circuit in the touch position detection device disclosed in FIG. 4. It is a flowchart which shows the operation | movement step of the processing function of the row calculation of FIG. FIG. 5 is an explanatory diagram showing the occurrence of masking in the detection process in the touch position detection device disclosed in FIG. 4. FIG. 5 is an explanatory diagram showing touch position information in a detection process in the touch position detection device disclosed in FIG. 4. It is a schematic block diagram which shows one Embodiment in the touch position detection apparatus by this invention. It is a timing chart which shows the timing of the detection process in the touch position detection apparatus disclosed in FIG. It is a flowchart which shows the operation | movement step of the processing function of the X coordinate arithmetic circuit in the touch position detection apparatus disclosed in FIG. It is explanatory drawing which shows the touch position information in the process of the detection process in the touch position detection apparatus disclosed in FIG.

[Embodiment 1]
Next, the basic configuration content of the first embodiment according to the present invention will be described.

As shown in FIG. 4, the first embodiment is a position detection device for a resistive touch panel matrix type touch panel. The touch panel position detection device is a resistive touch screen in which first and second substrates are arranged to face each other. A matrix-type touch panel 6a, a row electrode drive circuit 7 for obtaining an output signal from a row electrode provided on the first substrate of the touch panel 6a, and a column electrode provided on the second substrate of the touch panel 6a. A column electrode driving circuit 8 that applies an input signal to the column; a timing generation circuit 9 that outputs a pulse signal for determining the timing of signal detection processing to the row electrode driving circuit 7 and the column electrode driving circuit 8; A memory 10 for temporarily storing detected signals; a coordinate calculation circuit 11a for determining a touch position on the touch panel based on the detected signals; It has a configuration including a CPU (Central Processing Unit) unit (hereinafter referred to as "CPU") 12 for controlling the operation function in the road.
Moreover, in the position detection apparatus of this embodiment, the position detection process part 21a which consists of the row electrode drive circuit 7, the memory 10, and the coordinate calculation circuit 11a shall be formed.

  Here, the resistive film type matrix type touch panel 6a of the present embodiment will be described with reference to FIG. The touch panel 6a has substantially the same configuration as the touch panel in the related art (FIG. 1), and is transparent on a transparent insulating substrate such as two PET films and glass plates arranged opposite to each other. It is assumed that strip-shaped electrodes (row electrodes 13 and column electrodes 14) made of a conductive material are formed.

Here, when it is assumed that the touch panel 6a is touched with a finger, it is necessary that at least two electrodes (column electrodes 14) are set on the substrate to be touched (pressing side substrate: corresponding to the second substrate). For this reason, the electrode pitch (the sum of the electrode width and the interval) is desirably 4 mm or less.
Further, as described above, the plurality of column electrodes 14 to which the input signal for detecting the touch position is applied are provided on the pressing side substrate.
Further, the non-pressing side substrate (corresponding to the first substrate (FIG. 1)) arranged to face the pressing side substrate has a plurality of row electrodes 13 that detect signals from the column electrodes 14 by contacting. .

Further, the column electrode 14 and the row electrode 13 are formed in directions perpendicular to each other. In the present invention, the formation direction of the row electrode 13 with respect to the column electrode 14 is not essential. In addition, a dot-shaped spacer having a height of about 5 to 10 μm is formed on one of the two substrates.
Further, one end of each column electrode 14 is provided with an external terminal 15 (a part of the column electrode drive circuit 8) for applying an input signal. The external terminal 15 is different from each other in the adjacent column electrodes 14. Thus, the external terminal 15 is provided at both ends (upper and lower sides in FIGS. 4 and 5) of the operation (touch panel) surface.

  That is, the external terminals 15 are installed on the touch panel lower side (FIG. 5) for the column electrodes X1, X3,... And the touch panel upper side (FIG. 5) for the column electrodes X2, X4,. Is done. These external terminals 15 are connected to the column electrode drive circuit 8.

  The row electrode 13 is connected to the row electrode drive circuit 7 on the left side of the touch panel (FIGS. 4 and 5). Further, in the touch panel, intersections between the row electrodes 13 and the column electrodes 14 are arranged in a matrix, and an intersection between one row electrode 13 and one column electrode 14 serves as a switch. The column electrode 14 and the row electrode 13 are brought into contact with each other to conduct the input signal to the row electrode 13.

For this reason, when the user touches the touch panel 6a according to the present embodiment, an input signal from the column electrode 14 is detected as an output signal from the row electrode 13 via a switch formed by an intersection of the row electrode 13 and the column electrode 14. Is done.
Here, the position detection processing unit 21a determines (touches) the touch position on the touch panel by detecting (determining) from which column electrode the input signal is output as the output signal.

[Description of Operation of First Embodiment]
Next, the overall operation of the position detection apparatus according to the first embodiment will be outlined.
First, the column electrode drive circuit 8 and the row electrode drive circuit 7 sequentially scan and drive the column electrodes and the row electrodes, and the position detection processing unit 21a is synchronized with the timing at which the input signal is applied to the column electrodes. Then, an output signal from the row electrode is detected (output signal detection step), and the magnitude of the output signal is compared with a first threshold value set in advance and larger than the first threshold value. The case is determined as a touch, and information indicating the position of the touch is held as first touch position information (first touch position determination step),
Next, the magnitude of the output signal is compared with a preset second threshold value that is smaller than the first threshold value, and the case where the magnitude of the output signal is greater than the second threshold value is touched. And information indicating the position of the touch is held as second touch position information (second touch position determination step).
Next, the coordinate calculation circuit 11a determines that the logical sum of the coordinates determined to be touch in the first touch position information and the coordinates determined to be touch in the second touch position information adjacent to the coordinates is touch. The final touch position information is determined as final coordinates (final touch position determination step).

  Here, with respect to the output signal detection step, the first touch position determination step, the second touch position determination step, and the final touch position determination step, the execution contents may be programmed and executed by a computer. Good.

This will be described in detail below.
First, processing for detecting a touch position on the touch panel 6a will be described with reference to FIG. FIG. 6 is a timing chart showing signal transmission timings for detecting the touch position using the position detection device of the touch panel 6a shown in FIG.

  When the position detection processing unit 21a detects that the touch panel has been touched, the interrupt signal output from the row electrode drive circuit 7 is recognized by the CPU 12, and the CPU 12 transmits a corresponding signal group to the timing generation circuit 9. To do.

  The timing generation circuit 9 outputs, to the column electrode drive circuit 8 and the row electrode drive circuit 7, pulse-shaped detection start signals for determining the detection process start timing based on the signal transmitted from the CPU 12. . Here, the application period of the detection start signal is set to be equal to the reciprocal (detection period) of the detection frequency of the touch panel.

In addition, the timing generation circuit 9 generates a pulsed XY scanning start signal for notifying the timing for starting input signal application and output signal detection of the row electrode and the column electrode together with the detection start signal, the row electrode drive circuit 7 and the column electrode. Output to the drive circuit 8.
This XY scan start signal is output twice in the detection cycle, and the first time is output at the same timing as the detection start signal, and the second time is output to the midpoint of the detection cycle.
Here, from the output of the first detection start signal to the output of the second detection start signal, the output of the first detection start signal of the next detection cycle from the output of the first detection period 1012, the second detection start signal. The period up to is the second detection period 102 (FIG. 6).

Further, the timing generating circuit 9, at the timing when the first XY scanning start signal is output to the column electrode driving circuit, the column electrodes X1, X2, · · ·, selectively input signal having a pulse width t _X in the order of Xn Apply to. Here, it is assumed that the column electrode is set in a high impedance state during a period in which no input signal is applied. Further, in the period t _X the input signal to the column electrodes are applied, the detection of the output signals of all the row electrodes is performed.

Next, the output signal of the row electrode is converted into a digital signal by a comparator built in the row electrode drive circuit 7.
Specifically, for example, when the output signal from the row electrode is larger than a preset threshold value of the comparator, the H level signal is output, and when the output signal is small, the L level signal is output. Here, the row electrode drive circuit 7 recognizes the row in which the H level signal is detected as a touch, and stores the touch position information of each column.

Further, the row electrode driving circuit 7 determines touches of all rows based on the first threshold value in the first detection period 101 (threshold value determination).
Next, after the application of the input signal to the column electrode Xn is completed, the row electrode drive circuit 7 performs the first detection in which the touch position information of each column stored in the row electrode drive circuit 7 is output from the timing generation circuit 9. The first touch position information is stored in the memory 10 at the timing of the read signal set in the period 101.

Similarly, after the first touch position information is stored in the memory 10, the second XY scanning start signal is output to the column electrode drive circuit at the timing of the column electrodes X1, X2,. order input signal having a pulse width t _X is selectively applied, the row electrode driving circuit 7 detects the output signals of all the row electrodes in the period t _X.
In the second detection period 102, it is assumed that the threshold value of the comparator is set to a second threshold value that is smaller than the first threshold value.
Here, the touch position information of each column stored in the row electrode drive circuit 7 is stored as second touch position information at the timing of the read signal set in the second detection period 102 output from the timing generation circuit 9. 10.

  The first threshold value is desirably set to a high value so that a weak signal due to deterioration of the touch panel or variations in resistance values of various wirings in other position detection devices is not recognized as a touch. The second threshold value is preferably set to a value smaller than the first threshold value, and is set to a low value so that a small output signal including the weak signal is recognized as a touch. is there.

  Thereby, for example, when masking occurs at the time of multiple touches on the touch panel, the output signal corresponding to the masked touch position is a very small value, so that the first threshold value is not recognized. In the threshold determination based on the second threshold set to a value smaller than the threshold, the masked touch can be reliably recognized.

  Next, after the second touch position information is stored in the memory 10, the first and second touch position information is transmitted by the CPU 12 to the coordinate calculation circuit 11a.

  The coordinate calculation circuit 11a calculates a logical sum of the coordinates recognized as the touch of the first touch position information and the coordinates recognized as the touch of the second touch position information adjacent to the coordinates, and based on the calculation result. The final touch position information is determined and is output to the CPU 12.

  Here, the processing operation in the coordinate calculation circuit 11a will be described based on the flowchart of FIG. Here, it is assumed that the matrix of the touch panel has M rows and N columns.

The coordinate calculation circuit 11a sets the i-th row to be processed from the first row (1 → i), performs a row calculation on this i-th row (row calculation), and then sets the i-th row to 1 It is set in the ascending i + 1th row (i + 1 → i), and it is determined whether this ith row is greater than M in the upper limit M row, and the set i is not greater than the upper limit M. In this case, an arithmetic process is performed on the i-th row (row operation). If i is a value greater than M in the Mth row, which is the upper limit (Yes), the process ends.
As a result, the coordinate calculation circuit 11a recursively (repeatedly) executes line calculations from the first line to the Mth line.

Next, the calculation process of the i-th row in the coordinate calculation circuit 11a will be described based on the flowchart of FIG. This calculation process is recursively processed from the first column to the Nth column.
Here, A _{i, j} , B _{i, j} , and C _{i, j} are data indicating the i-th row and j-th column data of the first touch position information, the second touch position information, and the final touch position information, respectively. To do.
Further, when the data at the coordinates of A _{i, j} , B _{i, j} , and C _{i, j} is 0, it indicates that there is no touch, and 1 indicates that there is a touch.

First, the coordinate calculation circuit 11a determines temporary data in the 0th column prior to performing the calculation process in the 1st column. Similarly, prior to the processing of the Nth column, a temporary data value of the (N + 1) th column is set. Here, the data value is set to 0 (step S0: FIG. 8).
In addition, this step S0 is a step required in the process of step S3 mentioned later.

Next, the coordinate calculation circuit 11a sets the first column in the matrix to the jth column indicating that it is a processing target (1 → j), and compares the data values in A _{i, j} and B _{i, j} .
Here, when the data values of A _{i, j} and B _{i, j} are equal (Yes: Step S1), when A _{i, j} = B _{i, j} = 0 _, the data value of C _{i, j} is determined to be 0. To do. When A _{i, j} = B _{i, j} = 1 _, the data value of C _{i, j} is determined to be 1 (step S2). That is, in step S2, a process for _converting the data value of A _{i, j} into data of C _{i, j} is performed.

On the other hand, when the data values of A _{i, j} and B _{i, j} are different (No: step S1), when A _{i, j} = 0, B _{i, j} = 1, that is, the first threshold value If it is not determined to be touch (A _{i, j} = 0) and it is determined to be touch with the second threshold (B _{i, j} = 1), the data of A at the position adjacent to the touch position to be processed is 0. It is determined whether or not (step S3).

In the case of the processing in the first column, since the adjacent data is only the data in the second column, the temporary data in the 0th column is determined in order to avoid the occurrence of an error in the processing result (value). (Step S0).
Similarly, in the process of the Nth column, since the adjacent data is only the data of the (N−1) th column, the temporary data of the (N + 1) th column is determined in step S0 (step S0).

In this step _{S3, A i determination,} both sides of _{j (A i, j-1} , A i, j + 1) the touch position if the data value is 0 for _{C i,} the data value of _j is 0 (decision (Yes: Step S3), the process of Step S2 is then performed.

On the other hand, _{A i} in step _S3, both sides of _{j (A i, j-1} A i, j + 1) the touch position _{C i} if at least one of the one of the data _values, the data values of _j is 1 and judge.
For this reason, in step S4, a process of setting the data value of B _{i, j as} the data value of C _{i, j} is performed.

  Next, the j + 1 column obtained by increasing j by 1 is set as a processing target (j + 1 → j), and it is determined whether or not this j column is larger than N of the Nth column as the upper limit. When j is not larger than the upper limit N (No), the arithmetic processing is performed for the j rows (to step S1). Further, when the set j is a value larger than N, which is the upper limit (Yes), the process ends.

  As described above, in the coordinate calculation circuit 11a according to the present embodiment, the coordinate (data value) recognized as touch as the final touch position information is subjected to the data value setting process by the coordinate calculation circuit 11a. It is determined as the logical sum of the coordinates recognized as touches of the touch position information and the data values at the coordinates recognized as touches of the second touch position information adjacent to those coordinates in the row direction.

  Next, based on FIGS. 9 and 10, the data value detection process in the position detection processing unit 21 a and the calculation process in the coordinate calculation circuit 11 a when masking due to multiple touches occurs on the touch panel in the present embodiment. This will be described in detail.

Here, it is assumed that the matrix structure of the touch panel is 10 rows and 10 columns.
In FIG. 9, an input signal is applied to the third column (third column from the left in FIG. 9) from the lower side of the drawing, and multiple touches (touch A and touch B) are applied to both ends of the touch panel. When detected, the touch in the first row and the third column of the touch A is masked by the touch B.

  FIG. 10A shows the first touch position information recognized based on the first threshold value. That is, a point where a signal larger (higher) than a preset first threshold is detected is detected (recognized) as a touch. FIG. 10B shows the second touch position information recognized based on the second threshold value, that is, a signal larger (higher) than the preset second threshold value is detected. The detected point is detected (recognized) as a touch. However, this second threshold value is set to a value lower than the first threshold value. In addition, it is assumed that a point recognized as a touch (coordinate value) is 1 and a point not recognized is 0.

Here, in the first touch position information corresponding to the first threshold value, the touch B is recognized as a touch as shown in FIG. 10A, but is included in the touch A (FIG. 9) 1 The third column is not recognized as a touch.
On the other hand, in the second touch position information corresponding to the second threshold value, the second threshold value is set lower than the first threshold value. Therefore, as shown in FIG. The third column is recognized as a touch even if the output signal is very small.

  Further, in the second touch position information corresponding to the second threshold value, as shown in FIG. 10 (b), the actual touch operation is performed as in the first row, the ninth column, and the first row, the tenth column. May be erroneously recognized as a touch by detecting an irrelevant weak signal.

  At this time, based on the position information detected as the first touch position information and the second touch position information, the coordinate calculation circuit 11a first displays the first touch position in the first row and the third column of the touch A in the second touch position information. Since it is adjacent to the coordinates (first row, second column) recognized as touch of information, it is recognized as touch in the final touch position information (FIG. 10C). Thereby, it is possible to effectively suppress the occurrence of masking in which the touch position to be detected is not detected.

  Further, in the touch panel matrix structure of the first embodiment, since the input signals are applied to the adjacent column electrodes from opposite directions, even if the output signal becomes very small due to the occurrence of masking, The touch signal is recognized by the input signal, and thus, the touch can be reliably detected (recognized) even at the point where the masking occurs.

As shown in the first row and the ninth column and the first row and the tenth column in FIG. 10B, the coordinates of the second touch position information recognized as a touch by a weak signal unrelated to the touch are the first touch position. Since it is not adjacent to the coordinates recognized as touch by the information, it can be prevented that the touch is erroneously recognized by the final touch position information (final touch position information: FIG. 10C).
In this embodiment (touch panel touch position detection processing), the coordinates of the touch recognized by the second touch position information are determined as final touch position information based on the first touch position information. Can be effectively suppressed.

  Therefore, in this embodiment, the touch is recognized based on two different threshold values, and the final touch position information is determined based on the mutual positional relationship between the recognized values. Generation of masking at the time of multiple touches can be effectively suppressed without reducing the position detection accuracy.

[Embodiment 2]
Next, the position detection apparatus according to the second embodiment of the present invention will be described. Here, the same reference numerals are assigned to the same portions as those of the first embodiment described above.
As shown in FIG. 11, the position detecting device of a resistive film type matrix type touch panel (hereinafter referred to as “touch panel 6b”) according to the second embodiment is the same as the first embodiment described above (see FIG. 11). The touch position on the touch panel has the same configuration as 4), and the coordinate calculation circuit 11a of the position detection processing unit 21a performs a calculation process in units of one-dimensional data corresponding to each row electrode on the touch panel. This is different from the case of the first embodiment in that the X-coordinate calculation circuit 11b is used as a replacement.

[Description of Operation of Embodiment 2]
First, processing for detecting a touch position on the touch panel 6b will be described with reference to FIG. FIG. 12 is a timing chart showing timing for performing signal processing for detecting a touch position using the position detection device of the touch panel 6b shown in FIG.

  Here, when the position detection processing unit 21b including the X coordinate calculation circuit 11b, the memory 10, and the row electrode drive circuit 7 detects that the touch panel 6b is touched, an interrupt signal output from the row electrode drive circuit 7 is output. Is recognized by the CPU 12, and the CPU 12 transmits a corresponding signal group corresponding to this signal to the timing generation circuit 9.

  The timing generation circuit 9 transmits, to the column electrode drive circuit 8 and the row electrode drive circuit 7, a pulse-shaped detection start signal for determining the start timing of detection processing based on the signal transmitted from the CPU 12. . Here, the cycle in which the detection start signal is applied is set to be equal to the reciprocal (detection cycle) of the detection frequency of the touch panel.

In addition, the timing generation circuit 9 generates a pulsed Y-scanning start signal for notifying the timing for starting input signal application and output signal detection of the row electrode and the column electrode together with the detection start signal, the row electrode drive circuit 7, and the column It transmits to each electrode drive circuit 8.
Here, the timing generator 9, the timing of the application of the Y scan start signal, the row electrodes Y1, Y2, · · ·, outputs the detected cycle signal is selectively row electrodes of the pulse width t _Y in the order of Ym Shall be.

Here, the CPU 12 is set to connect the row electrode to which the detection cycle signal is not applied to GND. Further, in the period t _Y, sequentially input signals to all of the column electrodes are applied, the detection cycle signal row electrodes applied performs detection operation of the input signal for each column electrode during t _Y.
The detection cycle signal is output twice in the cycle of the Y scanning start signal.
Note that the periods during which the first and second detection cycle signals are applied are defined as a first row detection period 201 and a second row detection period 202, respectively (FIG. 12).

Next, an output signal detected by the row electrode driving circuit 7 in the first row detection period 201 is converted into a digital signal by a first threshold value of a comparator built in the row electrode driving circuit 7.
The row position touch position information is stored in the memory 10 as the first row touch position information by the row electrode drive circuit 7 based on the read signal output from the timing generation circuit 9 after the application of the detection cycle signal. To do.
Further, in the second row detection period 202, the second threshold value smaller than the first threshold value is converted into a digital signal based on the comparator, and stored in the memory 10 as second row touch position information based on the read signal. Is done.
In addition, the magnitude | size of a 1st threshold value and a 2nd threshold value shall be set similarly to Embodiment 1, respectively.

  Next, after the second row touch position information is stored in the memory 10, the CPU 12 transmits the first and second row touch position information to the X coordinate calculation circuit 11b.

The X coordinate calculation circuit 11b calculates a logical sum of the coordinates recognized as touches of the first row touch position information and the coordinates recognized as touches of the second row touch position information adjacent to those coordinates, Based on this calculation result, one-dimensional final row touch position information is generated and output to the row touch position information CPU 12.
The above-described processing is sequentially performed on all the row electrodes, thereby generating two-dimensional touch position information (corresponding to final touch position information).

Here, the processing operation in the X coordinate calculation circuit 11b will be described based on the flowchart of FIG.
In the present embodiment, the matrix of the touch panel 6b is assumed to be N columns. A _j , B _j , and C _j indicate the data values of the j-th column of the first row touch position information, the second row touch position information, and the last row touch position information, respectively. 0 indicates no touch, and 1 indicates touch. Further, the calculation processing by the X coordinate calculation circuit 11b is recursively performed from the first column to the Nth column.

First, the X coordinate calculation circuit 11b sets the data values of A ₀ and A _{N + 1} to 0 (step S0: FIG. 13). This step S0 is a step necessary for the processing of step S3 described later.

Next, the X coordinate calculation circuit 11b sets A ₁ and B ₁ to A _j and B _j indicating the calculation target (1 → j), and compares the data values in A _j and B _j (step S1). ).
When A _j = B _j = 0, the data value of C _j is set to 0, and when A _j = B _j = 1, the data value of C _j is set to 1 (step S2). That is, in step S2, a process of setting the data value of A _{j to} the data value of C _j is performed.

On the other hand, when the data values in A _j and B _j are different (No: step S1 (FIG. 13)), for example, when A _j = 0 and B _j = 1, it is determined that the first threshold value is a touch. First, since it is determined that the touch is determined by the second threshold determination, it is determined whether or not the data of A _j at the positions adjacent to the touch position to be processed is 0 (step S3).

In the case of the processing of the first column, the data value of the adjacent column is only the data of the second column, so that a temporary data value of the 0th column is determined in advance in order to avoid an error in the processing result. It is assumed (step S0). Similarly, in the case of the processing of the Nth column, since the adjacent data is only the data value of the (N−1) th column, the temporary data of the (N + 1) th column is determined in advance in step S0. Therefore, the data values on both sides of A _j in step _{S3 (A j-1, A} j + 1) is the data value of C _j touch position if 0 is set 0, then the process of step S2 is Done.

Further, the X coordinate calculation circuit 11b determines that the C _j data at the touch position is 1 if at least one of the data values (A _j−1 , A _{j + 1} ) on both sides of A _j is 1 in step S3. Therefore, a process of setting the data value of B _{j as} the data value of C _j is performed (step S4).

  Next, the j + 1 column obtained by increasing j by 1 is set as a processing target (j + 1 → j), and it is determined whether or not this j column is larger than N of the Nth column as the upper limit. When j is not larger than the upper limit N (No), the arithmetic processing is performed for the j rows (to step S1). Further, when the set j is a value larger than N, which is the upper limit (Yes), the process ends.

  As described above, the X coordinate calculation circuit 11b according to the present embodiment has been recognized as the touch of the first row touch position information and the touch of the second row touch position information adjacent to this coordinate. The final row touch position information is set as a logical sum with the coordinates.

  Next, similarly to the case shown in FIG. 9 in the first embodiment, the processing operation by the X coordinate arithmetic circuit 11b when masking occurs in the present embodiment will be described.

  First, when multiple touches (touch A and touch B) are detected at both ends of the touch panel, the touch of the third column of touch A is touched in the first row of row electrodes on the touch panel (6b) as shown in FIG. Masked by B.

First, what extracted the touch position information of the 1st line in FIG. 7 is shown to FIG. Here, the point recognized as a touch is represented by 1, and the point not recognized is represented by 0.
Here, in the first row touch position information corresponding to the first threshold value (by the first threshold value determination), as shown in FIG. 14A, the masked third column is not determined to be a touch. .

On the other hand, in the second row touch position information corresponding to the second threshold value (according to the second threshold value determination), the threshold value is set low, and as shown in FIG. The third column of A is recognized even when the output signal is small.
Further, in FIG. 14B, as shown in the ninth and tenth columns, there are points that are erroneously recognized as touches by detecting weak signals unrelated to touch.

  Here, based on the first row touch position information and the second row touch position information, the X coordinate calculation circuit 11b performs the third column of the second row touch position information as a touch of the first row touch position information. Since it is adjacent to the recognized coordinate (second column), as shown in FIG. 14C, it is set as touch in the final row touch position information. Thereby, the occurrence of masking is suppressed.

  As described above, in the present embodiment, as in the first embodiment, even if the output signal becomes very small due to the occurrence of masking, the occurrence of masking is recognized by the recognition by the input signal from the adjacent column electrode. It is also possible to reliably recognize (set) touch points.

  For example, as in the ninth and tenth columns in FIG. 14B, the coordinates recognized as the touch by the weak signal unrelated to the touch in the second row touch position information are the first. Since it is not adjacent to the coordinate recognized as touch in the row touch position information, it is determined that there is no touch.

  For this reason, in the position detection process of the touch panel of this embodiment, as in the first embodiment, the coordinates recognized as the touch in the second row touch position information are final based on the first row touch position information. Since the touch determination is made, occurrence of erroneous touch recognition can be effectively suppressed.

Therefore, the same effect as in the first embodiment can be obtained, and masking at the time of multiple touches can be suppressed without lowering the position detection accuracy.
Furthermore, in this embodiment, since the position information processed by the X coordinate calculation circuit 11b is one-dimensional data, the processing load of the memory 10 constituting the position detection processing unit 21b can be effectively reduced. Have

  The present invention can be effectively applied to a touch panel position detection device mounted on an information device that uses a display as an input interface, such as an OA device or a portable terminal.

DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 2nd board | substrate 3, 13 Row electrode 4, 14 Column electrode 6a, 6b Touch panel 7 Row electrode drive circuit 8 Column electrode drive circuit 9 Timing generation circuit 10 Memory 11a Coordinate calculation circuit 11b X coordinate calculation circuit 12 CPU
DESCRIPTION OF SYMBOLS 15 External terminal 21a, 21b Position detection process part 101 1st detection period 102 2nd detection period 201 1st line detection period 202 2nd line detection period

Claims (5)

A touch panel in which a row electrode formed in parallel along a preset row direction and a column electrode formed in a column direction intersecting the row direction are arranged to face each other, and the adjacent column electrode The touch panel based on an output signal output from the row electrode corresponding to the input signal by the contact between the column electrode and the row electrode, and an external terminal for applying an input signal in the opposite direction from different one end sides of the column electrodes A touch position detecting device including a touch position detecting unit that detects a position to which an external pressure is applied,
The touch position detector
An output signal detecting means for sequentially scanning and driving the column electrode and the row electrode, and detecting an output signal from the row electrode in synchronization with a timing of applying the input signal to the column electrode;
The magnitude of the output signal is compared with a first threshold value set in advance, and when it is larger than the first threshold value, it is determined as a touch, and information indicating the position of the touch is first touch position information. First touch position determination means held as:
When the magnitude of the output signal is compared with a second threshold value that is smaller than the preset first threshold value, and the magnitude of the output signal is greater than the second threshold value, touch Second touch position determination means for determining and holding information indicating the position of the touch as second touch position information;
The coordinates of the first touch position information determined as touch and the logical sum of the coordinates determined as touch among the coordinates of the second touch position information adjacent to the coordinates in the row direction And a final touch position determining means for determining final touch position information to be performed. A touch panel in which a row electrode formed in parallel along a preset row direction and a column electrode formed in a column direction intersecting the row direction are arranged to face each other, and the adjacent column electrode The touch panel based on an output signal output from the row electrode corresponding to the input signal by the contact between the column electrode and the row electrode, and an external terminal for applying an input signal in the opposite direction from different one end sides of the column electrodes A touch position detecting device including a touch position detecting unit that detects a position to which an external pressure is applied,
The touch position detector
Output signal detecting means for sequentially applying the input signals to the column electrodes and detecting an output signal from the row electrodes in synchronization with a timing of applying the input signals to the column electrodes;
The magnitude of the output signal is compared with a first threshold value set in advance, and when it is larger than the first threshold value, it is determined as a touch, and information indicating the position of the touch is first touch position information. First touch position determination means held as:
When the magnitude of the output signal is compared with a second threshold value that is smaller than the preset first threshold value, and the magnitude of the output signal is greater than the second threshold value, touch Second touch position determination means for determining and holding information indicating the position of the touch as second touch position information;
The coordinates of the first touch position information determined as touch and the logical sum of the coordinates determined as touch among the coordinates of the second touch position information adjacent to the coordinates in the row direction And a final touch position determining means for determining one-dimensional final touch position information corresponding to the row electrode from which the output signal from the row electrode has been detected.   An information input system comprising the touch position detecting device according to claim 1 as an input interface for information input. A touch panel in which a row electrode formed in parallel along a preset row direction and a column electrode formed in a column direction intersecting the row direction are arranged to face each other, and the adjacent column electrode An external terminal for applying an input signal in the opposite direction from one end side where the column electrodes are different from each other, and a touch for acquiring an output signal output from the row electrode corresponding to the input signal by contact of the column electrode and the row electrode A touch position detection apparatus comprising a position detection unit, wherein the touch position detection method detects a position where an external pressure is applied to the touch panel.
The column electrode and the row electrode are sequentially scanned and driven, and an output signal from the row electrode is detected in synchronization with the timing of applying the input signal to the column electrode,
The magnitude of the output signal is compared with a first threshold value set in advance, and when it is larger than the first threshold value, it is determined as a touch, and information indicating the position of the touch is first touch position information. Hold as
A touch is made when the magnitude of the output signal is compared with a preset second threshold value smaller than the first threshold value and the magnitude of the output signal is greater than the second threshold value. Determining and holding information indicating the position of the touch as second touch position information;
The logical sum of the coordinates determined to be touch in the first touch position information and the coordinates determined to be touch in the second touch position information adjacent to the coordinates in the row direction is determined as final touch position information. The touch position detection method characterized by the above-mentioned. A touch panel in which a row electrode formed in parallel along a preset row direction and a column electrode formed in a column direction intersecting the row direction are arranged to face each other, and the adjacent column electrode An external terminal for applying an input signal in the opposite direction from one end side where the column electrodes are different from each other, and a touch for acquiring an output signal output from the row electrode corresponding to the input signal by contact of the column electrode and the row electrode A touch position detection apparatus comprising a position detection unit, wherein the touch position detection program detects a position where external pressure is applied to the touch panel,
An output signal detection function for sequentially scanning and driving the column electrode and the row electrode, and detecting an output signal from the row electrode in synchronization with a timing of applying the input signal to the column electrode;
The magnitude of the output signal is compared with a first threshold value set in advance, and when it is larger than the first threshold value, it is determined as a touch, and information indicating the position of the touch is first touch position information. A first touch position determination function for performing processing to be held as
A touch is made when the magnitude of the output signal is compared with a preset second threshold value smaller than the first threshold value and the magnitude of the output signal is greater than the second threshold value. A second touch position determination function that performs processing for determining and indicating information indicating the position of the touch as second touch position information;
The logical sum of the coordinates determined to be touch in the first touch position information and the coordinates determined to be touch in the second touch position information adjacent to the coordinates in the row direction is determined as final touch position information. A touch position detection program in which a final touch position determination function is set in the touch position detection unit.

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