JP2005134992A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel device which has high detection accuracy and whose wiring space can be made narrow. <P>SOLUTION: A press position deciding means 35 of the touch panel device is equipped with: a calibration processing part 32 which determines a correction arithmetic expression on the basis of (1) specified coordinates previously set at at least nine points of corner parts of a detection area of a conductive film 22, the middle points between the respective corner parts and a center part, and (2) detected coordinates obtained by a detected coordinate acquiring means 33 by depression of the respective specified coordinates; and a correction arithmetic part 34 which calculates pressed coordinates, on the basis of the correction arithmetic expression, from the detected coordinates obtained by the detected coordinate acquiring means 33 by depression of an arbitrary position in the detection area. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a touch panel device that is installed on a display surface and detects a pressed position by a finger, a pen, or the like.

  As a conventional touch panel, there is known a resistance film type in which two substrates each having a resistance film formed on one surface are laminated via a spacer so that the respective resistance films face each other. ), Widely used in car navigation, personal computers and the like. As an example of the touch panel, a 5-wire type is known.

  The 5-wire touch panel has a total of five wires by connecting one wiring for sensing to the movable substrate and four wires for supplying power to the fixed substrate facing the movable substrate. Even when the resistance value of the resistance film of the movable substrate is not uniform or when the resistance value changes over time, it has the advantage of having a long life with little risk of affecting the detection accuracy. .

On the other hand, since the five-wire touch panel needs to arrange four electrodes around the resistive film on the fixed substrate, the equipotential lines are curved by these electrode resistances, and the detection position and the actual pressing position are There is a problem that the error is likely to occur. For this reason, for example, Patent Document 1 proposes to obtain an optimum value of the electrode resistance by using a predetermined calculation formula to reduce the error.
JP 2002-99389 A

  According to the touch panel described in Patent Document 1, the detection accuracy of the pressed position can be maintained satisfactorily, but the electrode shape must be made non-linear in order to obtain the optimum resistance value of the electrode. The wiring space (wiring space) necessary for wiring around the resistance film on the movable substrate becomes large. For this reason, there is room for further improvement in that a necessary wiring space can be secured even when the monitor is installed on a small monitor or when the monitor is installed on a monitor having a small frame portion even if it is large.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a touch panel device with high detection accuracy and capable of narrowing a wiring space.

  The object of the present invention is to provide a fixed substrate having a rectangular conductive film on which electrodes are arranged along each side of the conductive film, and a potential caused by pressing of the conductive film connected to an intersection of the electrodes. A potential detection unit for detecting, a detection coordinate acquisition unit for calculating a detection coordinate corresponding to the pressing position of the conductive film based on the potential detected by the potential detection unit, and a pressing coordinate from the detection coordinate of the pressing position. A touch panel device including a pressing position determination unit, wherein the pressing position determination unit is preset in at least nine points of a corner portion in the detection region of the conductive film, a midpoint of each corner portion, and a center portion. A calibration processing unit for determining a correction arithmetic expression based on the designated coordinates and the detected coordinates obtained in the detected coordinate acquisition means by pressing the designated coordinates; Wherein the resulting detected coordinates the detection coordinate acquisition unit is achieved by the touch panel device and a correction calculating unit for calculating the pressing coordinates based on the correction calculation equation by pressing the arbitrary position.

  According to the present invention, it is possible to provide a touch panel device with high detection accuracy and capable of narrowing a wiring space.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a touch panel device according to an embodiment of the present invention. As shown in FIG. 1, the touch panel device includes a touch panel body 2 attached to a display unit D of a terminal device T such as a personal computer, a vending machine, a ticket issuing device, and a game machine, and a control device 30. Yes.

  The touch panel body 2 includes a movable substrate 10 and a fixed substrate 20 that are arranged to face each other via a spacer (not shown). On the opposing surfaces of the movable substrate 10 and the fixed substrate 20, rectangular conductive films 12 and 22 are formed, respectively. The movable substrate 10 and the fixed substrate 20 are integrated by bonding the periphery with a double-sided adhesive tape or the like.

  As a material for the conductive films 12 and 22, an ITO (indium tin oxide) film is generally used. However, a tin oxide film, copper, aluminum, nickel, chromium, or the like can also be used. A laminate of materials or an alloy may be used. The conductive films 12 and 22 can be formed on the movable substrate 10 or the fixed substrate 20 by a PVD method such as a sputtering method, a vacuum evaporation method, an ion plating method, a CVD method, a coating method, a printing method, or the like. By interposing the coat layer, adhesion to the movable substrate 10 or the fixed substrate 20 and transparency can be enhanced. The sheet resistance values of the conductive films 12 and 22 are usually 100 to 500 Ω / □ for the conductive film 12 of the movable substrate 10 and 500 to 3000 Ω / □ for the conductive film 22 of the fixed substrate 20.

  The movable substrate 10 is preferably a film substrate having excellent mechanical strength in addition to heat resistance, weather resistance, non-shrinkage, chemical resistance, etc., for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Various films such as polyimide (PI), polyethersulfone (PES), polyetheretherketone (PEEK), polycarbonate (PC), polypropylene (PP), polyamide (PA), polyacryl, or thermoplastic norbornene polymer Or the laminated body of these 2 or more types of films can be illustrated. The thickness of the movable substrate 10 is usually about 0.05 to 5 mm, preferably about 0.1 to 0.3 mm, and the total light transmittance (JIS K 7361) is usually 50% or more, preferably 70% or more. More preferably, it is 90% or more. On the surface side of the movable substrate 10, hard coat processing or antireflection processing may be performed, or instead of such processing processing, a hard coat film, an antireflection film, a polarizing film, or the like may be laminated.

  A signal line is drawn from the conductive film 12 of the movable substrate 10. The signal line may be drawn directly from the movable substrate 10 or may be drawn through the fixed substrate 20.

  As the fixed substrate 20, a glass substrate such as soda glass, non-alkali glass, borosilicate glass, or quartz glass can be suitably used, and high-temperature processing is possible. The thickness of the fixed substrate 20 is preferably about 0.05 to 5 mm, and more preferably about 0.1 to 3 mm. The fixed substrate 20 can be a film substrate similarly to the movable substrate 10, and can be reinforced by laminating a support on the fixed substrate 20 made of a glass substrate or a film substrate.

  As shown in FIG. 2, the fixed substrate 20 is formed with a wiring space 23 serving as a wiring space by etching and removing the conductive film 22 along the outer periphery. The formation of the wiring space 23 is not necessarily performed by removing a part of the conductive film 22, and is performed by cutting the conductive film 22 by laser processing so that the insulation corresponding to the region corresponding to the wiring space 23 is maintained. May be.

  In the wiring space 23 of the fixed substrate 20, four electrodes 24 a, 24 b, 24 c, 24 d extending in a straight line with a constant cross section are arranged so as to form a frame body along each side of the conductive film 22, Wirings 25a, 25b, 25c, and 25d are drawn out from intersections (four places) of the electrodes 24a to 24d, respectively. The wirings 25 a to 25 d are provided on the wiring space 23 by printing or the like, and the tips are collected at one place and are thermocompression bonded by the flexible connector 26.

  The electrodes 24a to 24d can be formed by, for example, screen printing using a paste-like material such as silver, copper, silver, and carbon. As the material of the electrodes 24a to 24d, other materials can be selected as long as they are stable materials capable of keeping the volume resistance substantially constant, and the volume resistance value is obtained so as to obtain a desired electrode resistance value. Can be determined.

  The resistance values of the electrodes 24a to 24d are preferably 30 to 500Ω, more preferably 60 to 200Ω, and more preferably 80 to 100Ω from the viewpoint of preventing overcurrent to the conductive film 22 and reducing the bending distortion of the equipotential line. preferable. Moreover, it is preferable that the variation of the resistance value of each electrode 24a-24d is less than +/- 20% from a viewpoint of making curvature distortion small. If the lengths of the electrodes 24a to 24d are not the same because the lengths of the long side and the short side of the conductive film 22 are different, the resistance value can be adjusted by changing the electrode width.

  The control device 30 is connected to the flexible connector 26, detects a potential associated with the pressing of the movable substrate 10, a detection coordinate acquisition unit 33 that calculates a detection coordinate corresponding to the pressed position from the detected potential, And a pressing position determination unit 35 that obtains pressing coordinates from the detected coordinates of the pressing position. The control device 30 may be built in the terminal device T or may be configured to be externally attached to the terminal device T. Alternatively, the terminal device T itself can function as the control device 30 by installing a program necessary for the terminal device T.

  The pressing position determination unit 35 includes a calibration processing unit 32 that determines a correction calculation formula, a correction calculation unit 34 that calculates an actual pressing coordinate from a detection coordinate at an arbitrary pressing position of the fixed substrate 20 using a correction calculation formula, and And a memory unit 36 for storing processing data and processing results in the calibration processing unit 32 and the correction calculation unit 34.

  Next, the operation of the touch panel device having the above configuration will be described. At the time of purchase or maintenance of the touch panel device, it is preferable to perform calibration before the input operation of the touch panel device. This procedure will be described with reference to the flowchart shown in FIG.

  First, when a calibration signal is input to the control device 30 based on an operation of the terminal device T on which the touch panel device is mounted, the calibration processing unit 32 performs a calibration process according to the following procedure.

  First, a calibration screen is displayed on the display unit D of the terminal device T (step S1). As shown in FIG. 4, a total of nine points including corner portions P1, P3, P7, and P9, and midpoints P2, P4, P6, and P8 of each corner portion and a central portion P5 in the detection region of the conductive film 22 are designated coordinates in advance. And stored in the memory unit 36. On the calibration screen, markers (for example, x marks) are sequentially displayed at the designated coordinates P1 to P9.

When the operator presses the displayed marker with a finger or a pen, the conductive films 12 and 22 of the movable substrate 10 and the fixed substrate 20 are in point contact with each other, and the potential is detected by the potential detection unit 31. The detection coordinate acquisition unit 33 calculates detection coordinates (X coordinate and Y coordinate) corresponding to the pressed position based on the detection potential. Since the method for calculating the coordinates based on the detection potential is a well-known technique, a detailed description thereof will be omitted. The detected coordinates corresponding to the designated coordinates P1 to P9 thus obtained are the touch coordinates T1 (X _T1 , Y _T1 ), T2 (X _T2 , Y _T2 ),..., T9 (X _T9 , Y _T9 ). It is stored in the memory unit 36 (step S2).

  The calibration processing unit 32 first determines a mathematical expression (primary correction expression) used for the primary correction (step S3). The basic form of the primary correction formula is expressed by the following formulas (5) and (6) when the designated coordinates are (X, Y) and the touch coordinates are (x, y).

X = ax + by + cxy + d (5)
Y = ex + fy + gxy + h (6)
The coefficients a to h in the formulas (5) and (6) are the designated coordinates P1, P3, P7, and P9 of the corners of the detection area and the touch coordinates T1 (X _T1 , Y _T1 ), T3 (X _T3 , Y _T3 ), T7 (X _T7 , Y _T7 ), and T9 (X _T9 , Y _T9 ) can be calculated. In the present embodiment, the designated coordinates P1, P3, P7, and P9 of the corner portion are set to (0, 1000), (1000, 1000), (0, 0), and (1000, 0), respectively. What is necessary is just to determine suitably based on the magnitude | size of the detection area | region which can detect a press. If the coordinates cannot be pressed due to the bezel or the like, the designated coordinates of the corner may be (10, 990), (990, 990), or the like.

By obtaining the coefficients a to h in this way, the primary correction formula is expressed by the following formula (7) and formula (8). Here, the primary correction coordinates CAn are represented by (X _CAn , Y _CAn ), and the touch coordinates Tn are represented by (X _Tn , Y _Tn ).

X _CAn = aX _Tn + bY _Tn + cX _Tn Y _Tn + d (7)
Y _CAn = eX _Tn + fY _Tn + gX _Tn Y _Tn + h (8)
Next, using these mathematical formulas (7) and (8), from the touch coordinates T1 (X _T1 , Y _T1 ) to _T9 (X _T9 , Y _T9 ) corresponding to the designated coordinates P1 to P9, the primary correction coordinates CA1 are obtained. (X _CA1 , Y _CA1 ) to _CA9 (X _CA9 , Y _CA9 ) are calculated (step S4). The primary correction coordinates CA1 to CA9 thus obtained coincide with the designated coordinates for CA1, CA3, CA7, and CA9 corresponding to the designated coordinates P1, P3, P7, and P9 of each corner, but the designated coordinates between the corners. CA2, CA4, CA6, and CA8 corresponding to P2, P4, P6, and P8 are shifted to the center side from the designated coordinates as shown in FIG. This phenomenon is considered to be based on the equipotential line in the detection region being curved, so that secondary correction for correcting the curved line to a straight line is necessary.

Therefore, the curved lines L1, L2, L3, L4 are first approximated from the primary correction coordinates CA1, CA3, CA7, CA9 of each corner so that the primary correction coordinates CA2, CA4, CA6, CA8 are in the vicinity of the vertex (step S5). ). For example, the curved line L1 connecting the primary correction coordinates CA7, CA8, and CA9 and the curved line L2 connecting the primary correction coordinates CA1, CA4, and CA7 can be expressed by the following formulas 9 and 10, respectively. _{CA7, Y CA7), CA8 (} X CA8, Y CA8), CA9 (X CA9, Y CA9), _{and, CA1 (X CA1, Y CA1} ), CA4 (X CA4, Y CA4), CA7 (X CA7, Y Based on _CA7 ), the coefficients i to k and the coefficients l to n can be calculated. The same applies to the curved lines L3 and L4.

Y _CAn = iX _CAn ² + jX _CAn + k (9)
(N = 7, 8, 9)
X _CAn = lY _CAn ² + mY _CAn + n (10)
(N = 1, 4, 7)
Based on the four curved lines L1 to L4 thus obtained, a mathematical expression used for the secondary correction is determined as follows (step S6). For example, as shown in FIG. 5, for a point PL1 (X _L1 , Y _L1 ) on the curved line L1, the correction amount P _{y in the} Y direction matches the deflection amount of the curved line L1 at that point, P _y = Y _CA7 (or Y _CA9 ) −Y _L1 , and for the point PL2 (X _L2 , Y _L2 ) on the curved line L2, the correction amount P _{x in the} X direction matches the deflection amount of the curved line L2 at that point. _Therefore, P _x = X _CA1 (or X _CA7 ) −X _L2 .

On the other hand, in the detection region surrounded by the curved lines L1 to L4, the curvature (curvature) decreases as the center of the detection region is approached, and the curvature becomes 0 at the center of the detection region. Therefore, it is necessary to correct the correction amount according to the change in the degree of curvature. Since the change rate of the curvature can be approximated to be substantially constant with respect to the X direction or the Y direction, for example, an arbitrary point (X _u , Y in the lower half (including the boundary line) of the detection region is included. _{For u} ), the correction amount P _y in the Y direction can be obtained from the following equation 11 based on the Y direction correction amount for the point on the curved line L1 described above.

_{P y = (Y CA7 - (} iX u 2 + jX u + k)) × (Y m -Y u) / Y m ... (11)
_{(Where, Y m = Y 1 -Y 7} /2)
For the upper half (not including the boundary line) of the detection region, the Y direction correction amount for the point on the curved line L3 is first obtained, and the Y direction correction amount is calculated based on this. it can.

For any point (X _l , Y _l ) in the left half (including the boundary line) of the detection region, the correction amount P in the X direction is based on the Y direction correction amount for the point on the curved line L2. _X can be obtained by the following Equation 12.

_{P x = (X CA1 - (} lY u 2 + mY u + n)) × (X m -X l) / X m ... (12)
_{(Where, X m = X 1 -X 3} /2)
For the right half point (not including the boundary line) of the detection area, the X direction correction amount for the point on the curved line L4 is first obtained, and the X direction correction amount is calculated based on this. it can.

  Thus, after determining the mathematical expression (secondary correction expression) used for the secondary correction such as the mathematical expression 11 and the mathematical expression 12, using the secondary correction expression, the primary correction coordinates CA1 to CA9 to the secondary correction coordinates CB1 to CB9 are used. Is calculated (step S7). The secondary correction coordinates CB1 to CB9 coincide with the designated coordinates for CB1, CB3, CB7, and CB9 corresponding to the designated coordinates P1, P3, P7, and P9 of each corner portion, and the detection area frame corrected linearly. CB2, CB4, CB6, and CB8 are located on the line.

  However, the secondary correction coordinates CB2, CB4, CB6, and CB8 obtained in this way do not necessarily coincide with the designated coordinates P2, P4, P6, and P8, and the secondary correction coordinates CB5 also coincide with the designated coordinate P5. Is not limited. Therefore, based on the secondary correction coordinates CB1 to CB9, a mathematical expression used for the tertiary correction is determined (step S8).

Among tertiary correction coordinate _{CC1~CC9, CC2 (X CC2, Y} CC2), CC4 (X CC4, Y CC4), CC5 (X CC5, Y CC5), CC6 (X CC6, Y CC6), CC8 (X CC8, Y _CC8 ) is the same as the corresponding designated coordinates P2 (500, 1000), P4 (0, 500), P5 (500, 500), P6 (1000, 500), P8 (500, 0), respectively. This is set in advance so as to be stored in the memory unit 36.

In the tertiary correction, as shown in FIG. 6, the detection area is first divided so that the designated coordinates P1 to P9 are positioned at the four corners of the division area. That is, the detection areas are the areas having P1, P2, P4 and P5 as corners (area 1), the areas having P2, P3, P5 and P6 as corners (area 2), P4, P5, P7 and In the case of primary correction for each of the divided areas, the area is divided into four areas, namely, an area having P8 as each corner (area 3) and an area having P5, P6, P8, and P9 as each corner (area 4). The equation used for the third-order correction is determined in the same manner as described above. For example, for the regions 3, P4, P5, P7 and secondary correction coordinate corresponding to _{P8 CB4 (X CB4, Y CB4} ), CB5 (X CB5, Y CB5), CB7 (X CB7, Y CB7), CB8 ( and X _CB8, Y _CB8), tertiary correction coordinate _{CC4 (X CC4, Y CC4)} , CC5 (X CC5, Y CC5), CC7 (X CC7, Y CC7), based on the _CC8 (X CC8, Y CC8) By calculating the coefficients o to r and s to v in the following formulas 7 and 8, formulas used for the third order correction are obtained.

X _CCn = oX _CBn + pY _CBn + qX _CBn Y _CBn + r (13)
(N = 4, 5, 7, 8)
Y _CCn = sX _CBn + tY _CBn + uX _CBn Y _CBn + v (14)
(N = 4, 5, 7, 8)
Thus, the calibration is completed by determining the mathematical expression (third-order correction expression) used for the third-order correction for all the divided areas.

  At the time of actual input operation, the correction calculation unit 34 performs position correction by sequentially performing the above-described primary correction, secondary correction, and tertiary correction on the detected coordinates by pressing. This procedure will be described with reference to the flowchart shown in FIG.

For example, when an arbitrary point in the lower left area (corresponding to the area 3 in FIG. 6) in the detection area is pressed and the detection coordinates are (X _lu , Y _lu ), first, the same as the above Expression 7 and Expression 8 Primary correction is performed by the following formulas 15 and 16, and primary correction coordinates (X _lu1 , Y _lu1 ) are calculated (step S11).

X _lu1 = aX _lu + bY _lu + cX _lu Y _lu + d (15)
Y _lu1 = eX _lu + fY _lu + gX _lu Y _lu + h (16)
Next, from the primary correction coordinates (X _lu1 , Y _lu1 ), the Y direction correction amount P _y and the X direction correction amount P _x are obtained by the following equation 17 and equation 18 similar to the above equation 11 and equation 12, and the following equation 19 Then, the secondary correction coordinates (X _lu2 , Y _lu2 ) are calculated by using Equation 20 (step S12).

P _y = (Y _CA7 − (iX _lu1 ² + jX _lu1 + k)) × (Y _m −Y _u ) / Y _m
... (17)
(However, Y _m = Y _CA1 -Y _CA7 / 2)
P _x = (X _CA1 − (lY _lu1 ² + mY _lu1 + n)) × (X _m −X _l ) / X _m
... (18)
(However, X _m = X _CA1 -X _CA3 / 2)
X _lu2 = X _lu1 + P _x (19)
Y _lu2 = Y _lu1 + P _y (20)
Then, the secondary correction coordinate (X _lu2, Y lu2), by the equation 13 and equation 14 similar to the following equations 21 and equations 22 performs a cubic correction, calculates a tertiary correction coordinates _(X lu3, Y lu3) ( Step S13).

X _lu3 = oX _lu2 + pY _lu2 + qX _lu2 Y _lu2 + r (21)
Y _lu3 = sX _lu2 + tY _lu2 + uX _lu2 Y _lu2 + v (22)
Then, the tertiary correction coordinates (X _lu3 , Y _lu3 ) are output as corrected press coordinates (X _lua , Y _lua ) (step S14). The above is the explanation when the point in the lower left area in the detection area is pressed, but also when other areas are pressed, the mathematical formulas used for the secondary correction and the tertiary correction obtained by the calibration process are used. Thus, the corrected press coordinates can be obtained.

  8A to 8D show the detected coordinates, the coordinates after the primary correction, the coordinates after the secondary correction, and the coordinates after the tertiary correction, respectively, with black dots in the 1000 × 1000 detection region, Each intersection point corresponds to the actual pressing position. As is clear from FIG. 8, it was confirmed that the coordinates after the tertiary correction substantially coincide with the actual pressing position.

  Thus, according to the touch panel device of the present embodiment, the position correction of the pressed position can be accurately performed by software processing in the control device 30 without particularly considering the shape or arrangement of the electrodes as in the past. . Therefore, not only good detection accuracy can be obtained, but also a reduction in wiring space can be achieved by using linear electrodes having a constant cross section.

  In the present embodiment, at the time of calibration processing, nine points of touch coordinates T1 to T9 are obtained by displaying markers at nine points P1 to P9 on the screen. May be obtained. For example, in the case of obtaining 25 touch coordinates, after performing position correction on the four divided areas in the same manner as described above in the tertiary correction, each divided area is further divided into four to perform the same position correction. Therefore, position correction with higher accuracy becomes possible.

  As mentioned above, although one Embodiment of this invention was explained in full detail, the specific aspect of this invention is not limited to the said embodiment. For example, in the said embodiment, it is also possible to set it as the structure provided with the wired pen to which the signal wire | line was connected instead of providing a movable board | substrate. Or it is good also as what is called a capacitive touch panel comprised so that a fixed board | substrate may be directly touched with a finger | toe or a pen, without providing a movable board | substrate.

1 is a schematic configuration diagram of a touch panel device according to an embodiment of the present invention. It is a top view which shows the fixed board | substrate of the said touchscreen apparatus. It is a flowchart which shows the procedure of a calibration process. It is a figure which shows a calibration screen. It is a schematic diagram for demonstrating secondary correction | amendment. It is a schematic diagram for demonstrating tertiary correction | amendment. It is a flowchart which shows the procedure of a correction process. It is a figure which shows the result of a correction process.

Explanation of symbols

2 Touch panel body 10 Movable substrate 12 Conductive film 20 Fixed substrate 22 Conductive film 23 Wiring spaces 24a to 24d Electrodes 25a to 25d Wiring 30 Control device 32 Calibration processing unit 34 Correction operation unit 36 Memory unit T Terminal device D Display unit

Claims (4)

A fixed substrate having a rectangular conductive film and electrodes disposed along each side of the conductive film;
A potential detection means for detecting a potential associated with pressing of the conductive film connected to the intersection of the electrodes;
Detection coordinate acquisition means for calculating detection coordinates corresponding to the pressed position of the conductive film based on the potential detected by the potential detection means;
A touch panel device comprising a press position determination means for obtaining press coordinates from the detection coordinates of the press position,
The pressing position determining means is configured to detect the corner portion in the detection region of the conductive film, a middle point of each corner portion, and designated coordinates set in advance at least nine points in the center portion, and press the designated coordinates. A calibration processing unit that determines a correction arithmetic expression based on the detected coordinates obtained in the coordinate acquisition unit;
A touch panel device comprising: a correction calculation unit that calculates a pressed coordinate based on the correction calculation formula from the detected coordinate obtained by the detected coordinate acquisition unit by pressing an arbitrary position in the detection region. The calibration processing unit
When the designated coordinates are (X, Y) and the detected coordinates are (x, y),
X = a ₁ x + a ₂ y + a ₃ xy + a ₄ (1) and Y = a ₅ x + a ₆ y + a ₇ xy + a ₈ (2)
In the two equations, a primary correction equation is determined by obtaining coefficients a _{1 to} a ₈ from the designated coordinates corresponding to each corner and the detected coordinates corresponding to the designated coordinates,
A primary correction coordinate is calculated from the detection coordinates corresponding to each of the designated coordinates using the primary correction formula, approximating the curved line connecting the primary correction coordinates corresponding to each side of the conductive film, Determine the secondary correction formula based on the amount of deflection,
The correction calculation unit is
The primary coordinate is calculated from the detected coordinate using the primary correction equation, and the secondary coordinate is calculated from the primary correction coordinate using the secondary correction equation, thereby calculating the pressed coordinate. Item 10. The touch panel device according to Item 1. The calibration processing unit
Dividing the detection area so that the designated coordinates are located at the four corners of each division area,
When the designated coordinates are (X, Y) and the secondary correction coordinates are (x, y),
X = b ₁ x + b ₂ y + b ₃ xy + b ₄ (3) and Y = b ₅ x + b ₆ y + b ₇ xy + b ₈ (4)
In the two equations, a tertiary correction equation is determined by obtaining coefficients b _{1 to} b ₈ from the designated coordinates corresponding to the four corners of the divided area and the secondary correction coordinates corresponding to the designated coordinates,
The correction calculation unit is
The touch panel device according to claim 2, wherein the pressed coordinates are calculated by calculating the tertiary correction coordinates from the secondary correction coordinates using the tertiary correction formula. 4. The touch panel device according to claim 1, wherein the electrode has a constant cross section and is arranged to extend linearly along each side of the conductive film. 5.

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