JP7373825B2 - Analog resistive touch panel distortion correction method, analog resistive touch panel device - Google Patents

Description

The present invention relates to a distortion correction method for an analog resistive touch panel and an analog resistive touch panel device.

Conventionally, analog resistive touch panel devices have existed. A conventional analog resistive touch panel device has a structure in which a plurality of dot spacers, which are insulators, are arranged between a rectangular upper electrode and a lower electrode. A transparent conductive film with flexibility is used. When the upper part of this touch panel device is touched with a finger or a touch pen, the upper electrode at the touched position is bent, and the upper electrode and lower electrode contact in the area where no dot spacer exists and conduct electricity, so depending on the voltage value, The coordinates of the touched position are detected. The dot spacer is arranged to prevent the upper electrode and the lower electrode from accidentally coming into contact with each other due to external factors such as the environment.

Analog type resistive touch panel devices can be classified into 4-wire type, 5-wire type, etc. depending on the type of the device, and among these types, 4-wire type is often used. In the four-wire type, an X-coordinate circuit is formed on the upper electrode side, and a Y-coordinate circuit is formed on the lower electrode side. Since the X-coordinate circuit and the Y-coordinate circuit have different voltage gradients, when the voltage at the touched position is measured, the coordinates at that position are detected. Specifically, when position A is touched while voltage Vcc is applied between electrodes X1 and X2 of the X-coordinate circuit, voltage V1 is generated at electrode Y1 forming the lower electrode. At this time, since the transparent conductive film has a uniform resistance value, the ratio (a:b) between the distance a from the touched position A to the electrode X1 and the distance b from the touched position A to the electrode X2 is as follows. It is equal to the ratio (R11:R12) of the value of the resistor R11 and the value of the resistor R12. Based on this principle, the voltage value at the touched position A is calculated, and the calculated voltage value is A/D converted. As a result, the coordinates of the input position A in the X coordinate circuit are output as digital values. The Y-coordinate circuit operates on the same principle as the X-coordinate circuit, and the coordinates of the input position A are output as digital values.

By the way, in analog resistive touch panel devices as conventional technology, the target coordinates on the display screen and the target coordinates are different from each other due to parallax of the user performing the operation, installation tolerance between the touch panel and the LCD (Liquid Crystal Display), etc. There may be a discrepancy between the detected coordinates and the coordinates when the coordinates are accurately touched. Such deviations are also called "coordinate deviations," and when coordinate deviations occur, a function to correct the coordinate deviations (hereinafter referred to as the "calibration function") is generally used (for example, as disclosed in patents). Reference 1).

As mentioned above, the conventional analog resistive touch panel device is configured to specify the coordinates of the touched position, so the shapes of the upper electrode and the lower electrode must both be square. is the premise. For this reason, conventionally used calibration functions, including the technique proposed in Patent Document 1, assume a rectangular touch panel.

However, if you are trying to provide a product that gives a soft impression to buyers by making the product circular or oval, for example, you may want to make the touch panel part circular or approximately circular. There are also many requests regarding the design concept. For this reason, the development of circular or nearly circular analog type resistive touch panel devices is progressing, and at the same time, there is a need to realize a calibration function that is compatible with circular or nearly circular analog type resistive touch panel devices. ing.

Therefore, the present inventor has already proposed a circular or substantially circular analog type resistive touch panel device having a calibration function (Patent Document 2).

Japanese Patent Application Publication No. 2015-166949 Patent application No. 2018-015856 specification and drawings

However, the technique described in Patent Document 2 solves the problem of pincushion-shaped distortion occurring on the outside of the electrode of the resistive touch panel device shown in FIG. 12, and the problem of barrel-shaped distortion occurring inside the electrode. It becomes difficult to resolve. In other words, pincushion-shaped distortion occurring on the outside of the electrode refers to distortion in which the detection position is inside the pressed position, and barrel-shaped distortion occurring inside the electrode refers to distortion in which the detection position is inside the pressed position. This is a distortion in which the detection position is outside.

The present invention was made in view of the above situation, and an object of the present invention is to provide a method for improving linearity in a circular touch panel by correcting both barrel-shaped distortion and pincushion-shaped distortion. shall be.

In order to achieve the above object, a distortion correction method for an analog resistive touch panel according to the present invention includes:
A method for correcting distortion of an analog resistive touch panel in which circular or approximately circular electrodes are arranged, the method comprising:
a first correction step of performing contradictory distortion aberration correction on each of the outside and inside of the electrode;
a second correction step of performing magnification correction for each of the plurality of points arranged on the electrode;
In that order.

According to the present invention, it is possible to correct both barrel-shaped distortion and pincushion-shaped distortion, thereby improving linearity in a circular touch panel.

Further, in the first correction step, distortion aberration correction on the outside of the electrode is performed by
The X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin are respectively Xt and Yt, and the X coordinate and Y coordinate after correction when the center of the resistive touch panel is set as the origin. When the Y coordinates are each Xm and Ym, and the positive value parameter indicating the correction ratio is c1, the following equations (1) to (3) are applied.
Correction of distortion aberration inside the electrode in the first correction step,
The X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin are respectively Xt and Yt, and the X coordinate and Y coordinate after correction when the center of the resistive touch panel is set as the origin. It is preferable that the correction is performed by applying the following formulas (1) to (3), where each of the Y coordinates is Xm and Ym, and a parameter with a negative value indicating the correction ratio is c1. .
^R2 = ^Xt2 + ^Yt2 ...(1)
Xm=Xt+(Xt×c1×R2)...( ² )
Ym=Yt+(Yt×c1× ^R2 )...(3)

Further, the magnification correction in the second correction step may include:
Preferably, the magnification correction is performed for each of the five points arranged on the electrode.
According to the present invention, the following cases (1) to (4) can be appropriately handled. That is, (1) the case where the circular touch panel 1 used is small and does not require correction so sophisticated as to perform calibration on nine points. (2) A case where the ROM (Read Only Memory) capacity or CPU (Central Processing Unit) performance of the hardware used is not capable of withstanding advanced arithmetic processing. (3) A case where the center point obtained when performing calibration for five points can be used as the center point of the circular touch panel used in the lens aberration correction step. (4) By employing a proven algorithm for calibrating rectangular touch panels, it is possible to reduce the causes of trouble and appropriately respond to cases where it is thought that it will be easier to deal with problems when they occur.

The analog resistive touch panel device according to the present invention includes:
An analog resistive touch panel device in which circular or approximately circular electrodes are arranged,
A control unit is provided that performs contradictory distortion aberration correction on each of the outside and inside of the electrode, and then performs magnification correction on each of the plurality of points arranged on the electrode.
According to the present invention, it is possible to provide an analog resistive touch panel device that can correct both barrel-shaped distortion and pincushion-shaped distortion.

In addition, the control unit of the analog resistive touch panel device corrects distortion aberration outside the electrode by correcting each of the X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin. Xt and Yt, respectively, the X coordinate and Y coordinate after correction when the center of the resistive touch panel is the origin, Xm and Ym, respectively, and a positive value parameter indicating the correction ratio is c1. In this case, the following formulas (1) to (3) are applied to make corrections,
To correct distortion aberration inside the electrode, when the center of the resistive touch panel is set as the origin, the X coordinate and Y coordinate before correction are Xt and Yt, respectively, and the center of the resistive touch panel is set as the origin. When the X and Y coordinates after correction are respectively Xm and Ym, and the negative value parameter indicating the correction ratio is c1, apply the following equations (1) to (3). It is preferable to perform additional correction.
^R2 = ^Xt2 + ^Yt2 ...(1)
Xm=Xt+(Xt×c1×R2)...( ² )
Ym=Yt+(Yt×c1× ^R2 )...(3)

Further, it is preferable that the control unit of the analog resistive touch panel device performs magnification correction for each of the five points arranged on the electrode.

According to the present invention, it is possible to provide a method that can improve linearity in a circular touch panel by correcting both barrel-shaped distortion and pincushion-shaped distortion.

3 is a flowchart showing the flow of a distortion correction method for a resistive touch panel according to the present invention. FIG. 3 is a diagram showing a state of distortion corrected by the distortion correction method for a resistive touch panel according to the present invention. FIG. 2(A) shows the distortion between the pressed position and the detected position. FIG. 2(B) shows the distortion characteristics between the pressed position and the detected position. FIG. 3 is a diagram showing types of distortion aberration. FIG. 3(A) shows barrel-shaped distortion. FIG. 3B shows pincushion distortion. FIG. 3 is a diagram showing the content of calibration. FIG. 4 is a diagram showing the results of correction by the distortion correction method for a resistive touch panel according to the present invention. FIG. 5A shows the distortion between the pressed position and the detected position before correction is performed. FIG. 5(B) shows the distortion between the pressed position and the position after the lens aberration correction step. FIG. 5C shows the distortion between the pressed position and the position after the calibration step. FIG. 6 is a diagram showing positions on a circular touch panel used to calculate a value indicating linearity. FIG. 3 is a diagram showing values indicating linearity. FIG. 7(A) shows the pressed position before correction is performed. FIG. 7B shows values indicating linearity before correction for each block. FIG. 7C shows values indicating linearity after correction for each block. FIG. 7 is a diagram showing the contents of circular/square projection correction. FIG. 8(A) shows an image in which the characteristics of a square are projected onto a circle. FIG. 8(B) shows an image in which the characteristics of a circle are projected onto a square. FIG. 8C shows the results of circular and square projection correction. It is a figure showing the contents of grid correction. FIGS. 9A to 9D show the grid correction procedure in order. FIG. 9(E) shows the results of grid correction. 3 is a table showing the results of correction using the distortion correction method for a resistive touch panel according to the present invention, using predetermined evaluation values. It is a figure which shows the individual difference of several circular touch panels. 1 is a plan view of a resistive touch panel to which a resistive touch panel distortion correction method according to the present invention is applied; FIG.

A distortion correction method for a resistive touch panel according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below.

As shown in FIG. 1, a method for correcting distortion of a resistive touch panel according to an embodiment of the present invention corrects distortion of a circular touch panel using a predetermined correction formula used to calibrate distortion aberration, which is lens distortion. Distortion of a resistive touch panel including, in order, a lens aberration correction step (step S1), and a correction step (step S2) in which magnification is corrected for each of a plurality of points arranged on an electrode of a circular touch panel. This is a correction method.

In this method for correcting distortion of a resistive touch panel, barrel correction and pincushion correction are performed in combination in the lens aberration correction step (step S1), so that distortion peculiar to a circular touch panel is corrected. In addition, in the calibration step (step S2), since the unique distortion of each of the circular touch panels 1-1 to 1-n (n is an arbitrary integer value of 1 or more) is corrected, the circular touch panels 1-1 to 1-n are corrected. -N individual differences are corrected.
Thereby, the linearity of the circular touch panel 1 can be improved by correcting both the barrel-shaped distortion and the pincushion-shaped distortion.

Each component will be explained in detail below.

[Lens aberration correction step]
The lens aberration correction step is a step of correcting distortion of the touch panel using a predetermined correction formula used to calibrate distortion aberration, which is lens distortion.
In the lens aberration correction step, correction is performed using a correction formula created based on the fact that characteristics of distortion occurring outside and inside the electrode range are different. That is, as shown in FIGS. 2(A) and 2(B), distortion occurs in which the point P indicating the detection position is inside the point Q indicating the pressed position outside the curve A indicating the electrode range. There is a characteristic that. That is, since it has pincushion distortion characteristics as shown by the dotted line L1, the barrel-shaped distortion shown in FIG. 3(A) is reflected. This makes it possible to cancel out the characteristic of pincushion distortion. Furthermore, there is a characteristic that barrel-shaped distortion occurs inside the curve A indicating the electrode range. In other words, since it has a barrel-shaped distortion characteristic as shown by the broken line L2, the pincushion-shaped distortion shown in FIG. 3(B) is reflected. This makes it possible to cancel out the characteristic of barrel distortion.

Specifically, in the lens aberration correction step, for the area outside the curve A indicating the electrode range, the X and Y coordinates before correction are set as Xt and Yt when the center of the circular touch panel is set as the origin, and When the X and Y coordinates after correction when the center is the origin are Xm and Ym, and the positive value parameter indicating the correction ratio is c1, correction is performed using the following formulas (1) to (3). be exposed. In addition, for the area inside the curve A indicating the electrode range, the X and Y coordinates before correction when the center of the circular touch panel is set as the origin are Xt and Yt, and after correction when the center of the circular touch panel is set as the origin. When the X and Y coordinates of are Xm and Ym, and a negative value parameter indicating the correction ratio is c1, corrections are performed according to the following equations (1) to (3).
^R2 = ^Xt2 + ^Yt2 ...(1)
Xm=Xt+(Xt×c1×R2)...( ² )
Ym=Yt+(Yt×c1× ^R2 )...(3)

In this way, the circular touch panel 1 which was in the state shown in FIGS. 2(A) and (B) or FIG. 5(A) becomes the state shown in FIG. 5(B) by passing through the lens aberration correction step. . Note that the curve A indicates the range of the electrode, the point Q indicates the pressed position, the point P indicates the detection position, and the point R indicates the position after lens aberration correction.
That is, it can be seen that all the coordinates indicating the detected position are corrected to values close to the coordinates indicating the pressed position by lens aberration correction. Note that the value obtained by normalizing the variation in the coordinates indicating the position after lens aberration correction with respect to the coordinates indicating the pressed position using a predetermined evaluation method is "15,865".

[Calibration step]
The calibration step is a step of correcting inherent distortion by performing calibration (magnification correction) on each of the circular touch panels 1-1 to 1-n.
In the calibration step, correction (magnification correction) is performed to eliminate individual differences among the circular touch panels 1-1 to 1-n. In this embodiment, as shown in FIG. 4, calibration is performed at five points C1 to C5. Note that the number of points to be calibrated is not particularly limited. For example, calibration can be performed on two points, four points, or nine points. However, the following cases (1) to (4) can be assumed as cases in which calibration is performed for five points. That is, (1) the case where the circular touch panel 1 used is small and does not require correction so sophisticated as to perform calibration on nine points. (2) Cases in which the ROM capacity and CPU performance of the hardware used are not capable of withstanding advanced arithmetic processing. (3) A case where the center point obtained when performing calibration for five points can be used as the center point of the circular touch panel used in the lens aberration correction step. (4) A case in which it is believed that by employing a proven algorithm for calibrating rectangular touch panels, it is possible to reduce the causes of trouble and make it easier to deal with problems when they occur.

In this way, the circular touch panel 1 which was in the state shown in FIG. 5(B) becomes the state shown in FIG. 5(C) through the calibration step. Note that the curve A indicates the range of the electrode, the point Q indicates the pressed position, the point P indicates the detection position, the point R indicates the position after lens aberration correction, and the point T indicates the position after calibration.
That is, it can be seen that, through the calibration, the coordinates indicating the position after lens aberration correction are corrected to values close to the coordinates indicating the pressed position. Note that the evaluation value obtained by normalizing the variation in the coordinates indicating the position after calibration with respect to the coordinates indicating the pressed position using a predetermined evaluation method was "9,655". Here, the evaluation value means that the smaller the numerical value, the higher the evaluation. Therefore, it can be seen that the evaluation value after calibration is even better than after lens aberration correction (15,865).

[Linearity]
As described above, the circular touch panel 1 can correct distortion through the lens aberration correction step and the calibration step. The result can also be calculated as a value indicating linearity.
Specifically, as shown in FIG. 6, information regarding the coordinates of each of the 84 points Q inside the curve A indicating the electrode range is obtained, and a predetermined calculation formula is applied to all the obtained coordinates. By doing so, a value indicating linearity can be calculated. That is, each of Xnl and Ynl is the linearity of the X-axis direction and the Y-axis direction, and each of Xm and Ym is the physical pressed position on the circular touch panel 1 expressed as an AD value (analog/digital conversion value). When Xt and Yt are each the AD value detected when the circular touch panel 1 is touched, a value indicating linearity is calculated by applying the following equations (4) and (5). be able to. Note that in the following equations (4) and (5), ABS() is an equation for calculating the absolute value of the value in parentheses.

・・・（４）

...(4)

・・・（５）

...(5)

The value indicating linearity is calculated for each of the 84 points Q that are the pressed positions by applying equations (4) and (5) above, and the closer it is to 0 (zero), the more linearity is maintained. It shows that Further, as shown in FIG. 7A, by dividing the area inside the curve A indicating the electrode range into a plurality of blocks, the value indicating linearity can be displayed in units of blocks. For example, since two points Q1 and Q2 exist in block B shown in FIG. 7(A), two points Q1 and Q2 exist in block B1 shown in FIG. 7(B), which shows the state before correction. A representative value (3.3%) indicating linearity is displayed. Furthermore, in block B1 shown in FIG. 7(B), which shows the state after the lens aberration correction step and the calibration step, a representative value (1.5%) indicating the linearity of the two points Q1 and Q2 is displayed. ing. That is, the linearity in block B1 is improved through the lens aberration correction step and the calibration step.

The values indicating the linearity of each block shown in FIGS. 7(B) and (C) are displayed in accordance with the following display rules (1) to (4). That is, (1) there is one value indicating linearity for one block. (2) Among the values indicating linearity in the X-axis direction and the values indicating linearity in the Y-axis direction, the larger value is displayed preferentially. (3) When a plurality of points Q exist in one block, the largest value among them is displayed preferentially. (4) Each block is classified and displayed according to the necessity of improving linearity.

Specifically, blocks with a linearity value of 2.0% or more are classified as blocks with the highest need to improve linearity, and blocks with a linearity value of 1.5% or more but less than 2.0% are classified as blocks with the highest linearity improvement. A block is classified as having the second highest need to improve linearity, and a block with a linearity value of 1.0% or more but less than 1.5% is classified as having the second highest need to improve linearity. A block that is classified as a low block and has a value indicating linearity of less than 1.0% is classified as a block whose linearity has the least need to be improved.
From the results classified in this way, it can be seen that the linearity is improved overall by going through the lens aberration correction step and the calibration step. That is, by going through the lens aberration correction step and the calibration step, both barrel-shaped distortion and pincushion-shaped distortion are corrected, so that the linearity of the circular touch panel can be improved.

[Study of correction method]
As described above, in the method for correcting distortion of a resistive touch panel according to the present invention, lens aberration correction is adopted as a method for correcting the distortion inherent in the circular touch panel 1, but the present invention is not limited to this. For example, circular/square projection correction or grid correction may be employed.

(Circle/square projection correction)
The circular/square projection correction corrects distortion that occurs when the characteristics of a square touch panel are directly projected onto the circular touch panel 1. Specifically, the distortion is corrected by projecting the touch characteristics from the circle onto the square using the following equations (6) to (9) that transform the circle into a square.

・・・（６）

...(6)

・・・（７）

...(7)

・・・（８）

...(8)

・・・（９）

...(9)

In other words, in circular/square projection correction, correction is performed by directly projecting the characteristics of a square touch panel onto a circular touch panel. Therefore, as shown in FIG. The premise is that it is detected as point b. In other words, point b on curve CL shown in FIG. 8(A) is obtained by correcting point a on straight line SL in the direction of arrow Y1.
Then, as shown in FIG. 8(B), point b on the curve CL is projected onto point a on the straight line SL. That is, a correction opposite to the correction shown in FIG. 8(A) is performed. Thereby, distortion can be canceled. That is, point a on the straight line SL shown in FIG. 8(B) is the point b on the curve CL corrected in the direction of the arrow Y2.

In this way, the circular touch panel 1 that was in the state shown in FIGS. 2A and 2B or 5A becomes the state shown in FIG. 7B by the circular/square projection correction. Note that the curve A indicates the range of the electrode, the point Q indicates the pressed position, and the point R indicates the position after circular/square projection correction.
That is, the positions included in the areas F1 and F2 are deteriorated due to the circular/square projection correction. This is because characteristics different from the assumed conceptual model were shown.
Note that the value obtained by normalizing the variation in the coordinates indicating the position after circular/square projection correction with respect to the coordinates indicating the pressed position using a predetermined evaluation method is "21,646".

(grid correction)
In grid correction, "coordinates indicating the position before correction when the pressed position is touched" (hereinafter referred to as "grid data") are stored in advance for several tens of points, and the pressed position is indicated from the stored coordinates. Calculate coordinates. In this embodiment, the correction is performed using grid data of 121 points.
Specifically, the grid correction is performed in the steps (steps S11 to S14) illustrated in FIGS. 9(A) to 9(D). Note that FIGS. 9(A) to 9(D) show an example in which grid data of four points is used.

That is, as shown in FIG. 9(A), coordinates indicating the positions of points Q1 to Q4 are stored as a preliminary preparation (step S11). Note that the coordinates indicating the positions of the points Q1 to Q4 are due to distortion in the direction of the arrow caused by the characteristics of the circular touch panel when the respective positions of the points R1 to Q4 are pressed.
Next, by pressing the center of points R1 to Q4, as shown in FIG. 9(B), coordinates indicating the position of point U, which is distorted due to the characteristics of the circular touch panel, can be obtained (step S12).
Once the coordinates indicating the position of point U have been determined, the distances from each of points Q1 to Q4 to point U are calculated as a percentage, as shown in FIG. 9(C) (step S13).
Then, the respective distance ratios from each of points Q1 to Q4 to point U are applied to the rectangle shown by dotted lines with points R1 to R4 as vertices shown in FIG. 9(D). Thereby, the coordinates indicating the point V which is the pressed position can be calculated.

In this way, the circular touch panel 1 which was in the state shown in FIGS. 2(A) and 2(B) or FIG. 5(A) becomes the state shown in FIG. 9(B) by grid correction. Note that the curve A indicates the range of the electrode, the point Q indicates the pressed position, and the point R indicates the position after grid correction.
That is, due to grid correction, grid data could not be obtained for positions included in areas F3 to F6. For this reason, it was not possible to correctly correct the outer peripheral portion of the circular touch panel 1. The reason why grid data could not be obtained means that it was difficult to generate grid data.
Note that the value obtained by normalizing the variation in the coordinates indicating the position after grid correction with respect to the coordinates indicating the pressed position using a predetermined evaluation method was "23,996".

(comparison)
As mentioned above, three types of correction were performed: lens aberration correction, circular/square projection correction, and grid correction, and when the results of each were compared using a predetermined evaluation method, the results shown in Figure 10 were obtained. . In other words, the evaluation value before correcting the distortion of the circular touch panel is "42,134", the evaluation value for lens aberration correction is "15,865", the evaluation value for circular/square projection correction is "21,646", and the evaluation value for grid correction is "15,865". The evaluation value was "23,996". As mentioned above, the smaller the evaluation value, the higher the evaluation. Therefore, among the lens aberration correction, circular/square projection correction, and grid correction, the best correction result was obtained with the lens aberration correction.

(Individual difference)
As mentioned above, when correcting the distortion of a circular touch panel, the best correction results can be obtained by correcting lens aberrations, but it is best to perform lens aberration correction in the same way for any circular touch panel. An experiment was conducted to see if it was possible to obtain correction results.
Specifically, as shown in FIG. 11, data before correction was obtained three times for each of the four circular touch panels 1-1 to 1-4. As a result, it was found that there were no large differences in the characteristics of each of the circular touch panels 1-1 to 1-4 between individuals. Therefore, when correcting the distortion of a circular touch panel, it can be said that the best correction result can be obtained by performing lens aberration correction on any circular touch panel in the same way.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the range that can achieve the purpose of the present invention are included in the present invention. It is. Further, various changes may be made without departing from the gist of the present invention.

In summary, the distortion correction method for a resistive touch panel can have the following configuration and can take various embodiments.
That is, the distortion correction method for a resistive touch panel to which the present invention is applied is as follows:
A method for correcting distortion of an analog resistive touch panel (for example, circular touch panel 1) in which circular or approximately circular electrodes (for example, the electrode range shown by curve A) are arranged,
a first correction step (for example, the lens aberration correction step in FIG. 1) in which contradictory distortion aberration correction is performed respectively on the outside and inside of the electrode;
a second correction step (for example, the calibration step in FIG. 1) of performing magnification correction (calibration) for each of the plurality of points arranged on the electrode;
In that order.
This makes it possible to provide a method for correcting both barrel-shaped distortion and pincushion-shaped distortion to improve linearity in a circular touch panel.

Further, in the first correction step, distortion aberration correction on the outside of the electrode is performed by
The X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin are respectively Xt and Yt, and the X coordinate and Y coordinate after correction when the center of the resistive touch panel is set as the origin. When the Y coordinates are each Xm and Ym, and the positive value parameter indicating the correction ratio is c1, the following equations (1) to (3) are applied.
Correction of distortion aberration inside the electrode in the first correction step,
The X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin are respectively Xt and Yt, and the X coordinate and Y coordinate after correction when the center of the resistive touch panel is set as the origin. When each of the Y coordinates is Xm and Ym, and the parameter with a negative value indicating the correction ratio is c1, it can be said that the correction is performed by applying the following formulas (1) to (3). .
^R2 = ^Xt2 + ^Yt2 ...(1)
Xm=Xt+(Xt×c1×R2)...( ² )
Ym=Yt+(Yt×c1× ^R2 )...(3)

Further, the magnification correction in the second correction step may include:
The magnification correction may be performed for each of the five points arranged on the electrode.

The analog resistive touch panel device according to the present invention includes:
An analog resistive touch panel device in which circular or approximately circular electrodes are arranged,
A control unit is provided that performs contradictory distortion aberration correction on each of the outside and inside of the electrode, and then performs magnification correction on each of the plurality of points arranged on the electrode.
Thereby, it is possible to provide an analog resistive touch panel device that can correct both barrel-shaped distortion and pincushion-shaped distortion.

In addition, the control unit of the analog resistive touch panel device corrects distortion aberration outside the electrode by correcting each of the X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin. Xt and Yt, respectively, the X coordinate and Y coordinate after correction when the center of the resistive touch panel is the origin, Xm and Ym, respectively, and a positive value parameter indicating the correction ratio is c1. In this case, the following formulas (1) to (3) are applied to make corrections,
To correct distortion aberration inside the electrode, when the center of the resistive touch panel is set as the origin, the X coordinate and Y coordinate before correction are Xt and Yt, respectively, and the center of the resistive touch panel is set as the origin. When the X and Y coordinates after correction are respectively Xm and Ym, and the negative value parameter indicating the correction ratio is c1, apply the following equations (1) to (3). corrections can be made.
^R2 = ^Xt2 + ^Yt2 ...(1)
Xm=Xt+(Xt×c1×R2)...( ² )
Ym=Yt+(Yt×c1× ^R2 )...(3)

Further, the control unit of the analog resistive touch panel device can perform magnification correction for each of the five points arranged on the electrode.

1, 1-1 to 1-4, 1-n: circular touch panel, A: electrode range, B1: block, a, b, C1 to C5, P, Q, Q1 to Q4, R, R1 to R4, T, U: point, L1: dotted line, L2: broken line, SL: straight line, CL: curve, S1, S2: each step, Y1, Y2: arrow, F1 to F6: area,

Claims (6)

A method for correcting distortion of a circular or substantially circular analog resistive touch panel, comprising:
The first region is a range in which pressing and detection by electrodes is performed, and includes a first region having a pincushion distortion characteristic and a second region having a barrel distortion characteristic. A first correction step in which contradictory distortion aberration correction is performed, such as performing correction to reflect barrel-shaped distortion aberration in the first region, and performing correction to reflect pincushion-shaped curvature aberration in the second region;
a second correction step of performing magnification correction for each of the plurality of points arranged on the electrode;
A distortion correction method for an analog resistive touch panel, including in that order. Distortion aberration correction in the first region in the first correction step includes:
The X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin are respectively Xt and Yt, and the X coordinate and Y coordinate after correction when the center of the resistive touch panel is set as the origin. When the Y coordinates are each Xm and Ym, and the positive value parameter indicating the correction ratio is c1, the following equations (1) to (3) are applied.
Distortion aberration correction in the second region in the first correction step,
The X coordinate and Y coordinate before correction when the center of the resistive touch panel is set as the origin are respectively Xt and Yt, and the X coordinate and Y coordinate after correction when the center of the resistive touch panel is set as the origin. When the Y coordinates are each Xm and Ym, and the parameter with a negative value indicating the correction ratio is c1, the following equations (1) to (3) are applied.
The method for correcting distortion of an analog resistive touch panel according to claim 1.
^R2 = ^Xt2 + ^Yt2 ...(1)
Xm=Xt+(Xt×c1×R2)...( ² )
Ym=Yt+(Yt×c1× ^R2 )...(3) The magnification correction in the second correction step includes:
Magnification correction performed for each of the five points arranged on the electrode,
The method for correcting distortion of an analog resistive touch panel according to claim 1 or 2. A circular or substantially circular analog type resistive touch panel device,
The first region is a range in which pressing and detection by electrodes is performed, and includes a first region having a pincushion distortion characteristic and a second region having a barrel distortion characteristic. In the second region, correction is performed to reflect barrel-shaped distortion aberration, and in the second region, correction is performed to reflect pincushion-shaped curvature aberration. comprising a control unit that performs magnification correction for each point;
An analog resistive touch panel device characterized by: The control unit corrects the distortion aberration in the first region by setting the X coordinate and Y coordinate before correction when the center of the resistive touch panel is the origin to be Xt and Yt, respectively, and correcting the distortion in the resistive touch panel. Let the X and Y coordinates after correction when the origin is the center of ), and
As distortion aberration correction in the second area, when the center of the resistive touch panel is set as the origin, the X coordinate and Y coordinate before correction are respectively Xt and Yt, and the center of the resistive touch panel is set as the origin. When the X and Y coordinates after correction are respectively Xm and Ym, and the negative value parameter indicating the correction ratio is c1, apply the following equations (1) to (3). make corrections,
The analog resistive touch panel device according to claim 4.
^R2 = ^Xt2 + ^Yt2 ...(1)
Xm=Xt+(Xt×c1×R2)...( ² )
Ym=Yt+(Yt×c1× ^R2 )...(3) the control unit performs magnification correction for each of the five points arranged on the electrode;
The analog resistive touch panel device according to claim 4 or 5.

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