JP5997842B2 - Touch panel system and electronic information device - Google Patents

Description

  The present invention relates to a touch panel system including a projected capacitive touch panel, an electronic information device including the touch panel system, and an operation method of the touch panel system.

  2. Description of the Related Art In recent years, touch panel systems that accept user instructions by detecting the position of an indicator (for example, a user's finger or stylus pen) that is in contact with or close to the detection surface of the touch panel have been used in mobile phones and personal computers. Increasingly, it is mounted on electronic information equipment. In particular, projection capacitive touch panels capable of multi-touch are increasingly mounted on electronic information devices.

  In such a touch panel system, an indicator that is in contact with or close to the detection surface is detected based on a processing result of a signal generated by the touch panel. However, the signal generated by the touch panel is affected by various influences such as contamination on the detection surface and aging deterioration in addition to the structural variation of the touch panel. For this reason, when the indicator is detected by directly using the processing result of the signal generated by the touch panel, the detection sensitivity of the indicator in the detection surface varies.

  As described above, when the detection sensitivity of the indicator in the detection surface varies, for example, the indicator may be easily detected at a certain position in the detection surface, but it may be difficult to detect the indicator at another position.

  Therefore, it is conceivable to perform calibration based on the processing result of the signal generated by the touch panel in a state where there is no indicator that is in contact with or close to the detection surface (hereinafter referred to as “non-instruction state”). When the calibration is executed, variations due to the various effects described above are suppressed in the processing result of the signal generated by the touch panel obtained thereafter. Therefore, it is possible to suppress variations in the detection sensitivity of the indicator within the detection surface.

  In addition, the signal generated by the touch panel varies depending on the use environment (particularly temperature). Therefore, in order to keep the detection sensitivity of the indicator constantly high, it is preferable to perform calibration periodically (for example, when the electronic information device including the touch panel system is started or when returning from the sleep state).

  However, when performing calibration, it is not always in the non-instruction state. For example, if calibration is executed in a state where the indicator is in contact with or close to a certain position on the detection surface, the processing result generated after that will contact or approach the detection surface for the certain position. The influence of the indicator to perform will be suppressed. For this reason, the detection sensitivity of the indicator is remarkably lowered at the certain position, and in some cases, it is impossible to detect the indicator.

  Therefore, in Patent Literature 1, when a calibration is performed by a human sensor (infrared sensor, ultrasonic sensor) that detects an indicator that touches or approaches the touch panel, the presence or absence of an object that is close to the detection surface of the touch panel. There has been proposed a touch panel system that can determine whether or not a calibration has failed by confirming the above.

JP 2012-118850 A

  However, the touch panel system proposed in Patent Document 1 requires a human sensor in addition to the touch panel in order to determine whether or not calibration has failed. Therefore, this touch panel system is problematic because the structure of the touch panel system and the signal processing method are complicated.

  Accordingly, the present invention provides a touch panel system capable of determining the presence or absence of a calibration failure with a simple structure, an electronic information device equipped with the touch panel system, and determining the presence or absence of a calibration failure using a simple method. An operation method of a touch panel system that can be performed is provided.

  To achieve the above object, the present invention processes a touch panel that generates a sense signal having an intensity corresponding to the presence or absence of an indicator that is in contact with or close to each position on a detection surface, and the sense signal generated by the touch panel. And a sense signal processing unit that generates a detection target signal that represents the presence or absence of the indicator that is in contact with or close to each position on the detection surface by the magnitude of each signal value corresponding to each position on the detection surface; A control unit that monitors the operation of the sense signal processing unit, and the sense signal processing unit is configured such that each signal value of the detection target signal to be generated becomes a reference value that is a predetermined value. The calibration for determining the calculation method of each signal value of the detection target signal is configured to be executed at a predetermined timing, and the control unit executes the calibration Wherein each signal value of the detection target signal sensing signal processing unit is generated, if a predetermined characteristic, to provide a touch panel system and it determines that the calibration has failed.

  Furthermore, in the touch panel system having the above characteristics, the reference value is a value between a pointer detection threshold and a calibration failure detection threshold, and a signal corresponding to a position on the detection surface of the detection target signal. When the value exceeds the indicator detection threshold away from the reference value, it indicates that the indicator is in contact with or close to the certain position on the detection surface, and the control unit It is preferable to determine that the calibration has failed when at least one of the signal values of the detection target signal is away from the reference value and exceeds the calibration failure detection threshold.

  Furthermore, in the touch panel system according to the above feature, the control unit is configured to move the signal value of the detection target signal away from the reference value and exceed the calibration failure detection threshold, and away from the reference value. It is preferable to determine whether or not the calibration has failed based on the comparison result between the number exceeding the indicator detection threshold.

  Furthermore, in the touch panel system according to the above feature, the control unit, for each of the signal values of the detection target signal, is separated from the reference value by a number that is far from the reference value and exceeds the calibration failure detection threshold. It is preferable to determine that the calibration has failed when there are more than the number exceeding the indicator detection threshold.

  Furthermore, in the touch panel system having the above characteristics, a first threshold value and a second threshold value that is a value between the first threshold value and the reference value are set as the indicator detection threshold value. As the calibration failure detection threshold value, a third threshold value and a fourth threshold value that is a value between the third threshold value and the reference value are set, and the control unit is configured to set the detection target signal to the calibration target signal. For each signal value, if the number that is apart from the reference value and exceeds the third threshold is greater than the number that is apart from the reference value and exceeds the first threshold, the calibration has failed. And determining, for each signal value of the signal to be detected, a number that exceeds the third threshold value away from the reference value and a number that exceeds the first threshold value apart from the reference value. Both are 0 And determining that the calibration has failed when the number that exceeds the fourth threshold away from the reference value is greater than the number that exceeds the second threshold away from the reference value. ,preferable.

  Furthermore, in the touch panel system having the above characteristics, it is preferable that the control unit controls the sense signal processing unit to execute the calibration again when it is determined that the calibration has failed.

  Furthermore, in the touch panel system having the above characteristics, when the control unit determines that the calibration has failed continuously for a predetermined number of times, the control unit controls the sense signal processing unit to execute the calibration again. ,preferable.

  Furthermore, in the touch panel system having the above characteristics, when the sense signal processing unit generates the detection target signal including the signal values corresponding to the positions on the detection surface as one frame, Preferably, the control unit determines whether or not the calibration has failed for each predetermined number of frames.

  Furthermore, in the touch panel system having the above characteristics, when the sense signal processing unit generates the detection target signal including the signal values corresponding to the positions on the detection surface as one frame, Preferably, the control unit determines whether or not the calibration has failed during a period from when the sense signal processing unit starts generating the detection target signal to when a predetermined number of frames are generated.

  Furthermore, in the touch panel system having the above characteristics, the touch panel is provided in parallel with each other along the detection surface, and a plurality of drive lines to which a predetermined voltage is applied from the outside, and the detection surface crossing the drive line A plurality of the sense lines that are provided in parallel with each other to generate the sense signal, and the magnitudes of the signal values of the detection target signal are the drive lines at the positions of the detection surface and It is preferable that it corresponds to the capacitance of the sense line.

  In addition, the present invention provides an electronic information device including the touch panel system described above.

  In addition, the present invention processes a sense signal having an intensity corresponding to the presence / absence of an indicator that is in contact with or close to each position on the detection surface of the touch panel, and whether or not the indicator is in contact with or close to each position on the detection surface Detection target signal generation operation for generating a detection target signal represented by the magnitude of each signal value corresponding to each position of the detection surface, and each signal value of the generated detection target signal is a predetermined value. A calibration operation for executing a calibration for determining a calculation method of each signal value of the detection target signal at a predetermined timing so that a reference value that is a value is obtained, and generated after the calibration is executed. A calibration failure determination operation for determining that the calibration has failed when each signal value of the detection target signal has a predetermined characteristic; It provides an operating method for a touch panel system characterized in that it is executed.

  According to the touch panel system having the above characteristics, it is possible to determine the presence or absence of calibration failure based on the detection target signal used for detection of the indicator. It becomes possible to judge.

The block diagram which shows an example of the whole structure of the touchscreen system which concerns on embodiment of this invention. FIG. 2 is a plan view and an equivalent circuit diagram illustrating an example of a structure of drive lines and sense lines included in the touch panel of FIG. 1. The schematic diagram which shows the state of the electric field of a touchscreen. The figure explaining the orthogonal parallel drive of a touch panel. The figure explaining the decoding method of the capacity | capacitance distribution signal in the case of carrying out orthogonal parallel drive of a touch panel. The graph shown about each of a capacity distribution signal, calibration data, and a detection target signal. The graph which shows the detection target signal produced | generated when an indicator contacts a detection surface. The graph which shows the detection target signal produced | generated after calibration fails. The graph which shows the threshold value used in order to determine the presence or absence of the failure of calibration. The table | surface which shows distribution of the signal value of a detection target signal in case a pointer is a finger | toe. The table | surface which shows distribution of the signal value of a detection target signal in case an indicator is a stylus pen. The table | surface which shows distribution of the signal value of the detection target signal produced | generated in the state which the palm contacted the detection surface after calibration succeeded. The circuit diagram shown about the capacity | capacitance formed when an indicator contacts the some position which the detection surface adjoined. The table | surface which shows distribution of the signal value of a detection target signal in case an indicator is a palm or a some finger | toe. The graph which shows in-plane distribution of the signal value of the detection target signal corresponding to each table | surface shown in FIG. The flowchart shown about the 1st operation example of a control part. The flowchart shown about the 2nd operation example of a control part. The flowchart shown about the 3rd operation example of a control part. The flowchart shown about the 4th operation example of a control part. The block diagram which shows the structural example of the electronic information apparatus which concerns on embodiment of this invention.

<< Touch panel system >>
<Example of overall structure and example of overall operation>
Hereinafter, a touch panel system according to an embodiment of the present invention will be described with reference to the drawings. First, an example of the overall structure and operation of a touch panel system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an example of the overall structure of a touch panel system according to an embodiment of the present invention.

  As illustrated in FIG. 1, the touch panel system 1 includes a touch panel 10, a drive line driving unit 20, a sense signal processing unit 30, a pointer position detection unit 40, and a control unit 50.

  The touch panel 10 includes a plurality of drive lines DL provided in parallel with each other along the detection surface P, and a plurality of sense lines SL provided in parallel with each other along the detection surface P and intersecting the drive lines DL. The drive line DL is provided so as to extend along the X direction (vertical direction in the drawing). On the other hand, the sense line SL is provided so as to extend along the Y direction (left and right direction in the figure) perpendicular to the X direction. That is, in the touch panel system 1 shown in FIG. 1, the drive line DL and the sense line SL intersect perpendicularly. Note that the drive line DL and the sense line SL may intersect at an angle other than vertical.

  2 is a plan view and an equivalent circuit diagram showing an example of the structure of drive lines and sense lines provided in the touch panel of FIG. 2A is a plan view showing the structure of the drive line DL and the sense line SL provided in the touch panel 10, and FIG. 2B is an equivalent circuit showing a circuit equivalent to the structure shown in FIG. FIG.

  As shown in FIGS. 2A and 2B, the drive line DL includes a drive line pad portion DLP having a locally increased area except for a portion intersecting the sense line SL. Similarly, the sense line SL includes a sense line pad portion SLP having a locally increased area except for a portion intersecting the drive line DL.

  At a portion where the drive line DL and the sense line SL intersect, an electrostatic capacitance (hereinafter simply referred to as “capacitance”) C is formed between the drive line DL and the sense line SL. In the structure illustrated in FIG. 2A, the capacitor C is formed mainly between the adjacent drive line pad portion DLP and the sense line pad portion SLP (that is, between the intersecting drive line DL and sense line SL). Is done. Note that the drive line pad portion DLP is not provided in the drive line DL, and the sense line pad portion SLP may not be provided in the sense line SL. Even in this case, the capacitor C is formed at the intersection of the drive line DL and the sense line SL.

  FIG. 3 is a schematic diagram showing a state of an electric field of the touch panel. FIG. 3A is a schematic diagram when the indicator is not present on the detection surface P, and FIG. 3B is a schematic diagram when the indicator (finger F) is present on the detection surface P. is there. In addition, in each of Fig.3 (a) and FIG.3 (b), the electric force line (electrostatic force line) is shown by the arrow. In FIGS. 3A and 3B, the drive line pad portion DLP and the sense line pad portion SLP are illustrated on the same plane for simplification of illustration. They may exist on different planes.

  As shown in FIG. 3B, when the finger F is brought into contact with or close to the detection surface P, the human body including the finger F behaves as a grounded object (that is, a shield). Therefore, as shown in FIG. 3B, when the finger F is brought into contact with or close to the detection surface P as compared to the case where the finger F does not exist on the detection surface P as shown in FIG. The capacitance formed by the drive line DL and the sense line SL is reduced. Note that the capacitance C similarly changes even when the drive line pad portion DLP is not provided in the drive line DL and the sense line pad portion SLP is not provided in the sense line SL.

  The drive line drive unit 20 repeatedly drives the drive lines DL with drive signals Di whose signal voltage combinations fluctuate in a predetermined order. As a result, a sense signal Si having a strength corresponding to the capacitance formed by the drive line DL and the sense line SL appears in the sense line SL.

  The sense signal processing unit 30 includes a sense signal acquisition unit 31, a signal value adjustment unit 32, and a storage unit 33. The sense signal acquisition unit 31 acquires the sense signal Si that appears on the sense line SL, and generates a capacitance distribution signal Ai. Further, the signal value adjustment unit 32 adjusts each signal value of the capacitance distribution signal Ai obtained from the sense signal acquisition unit 31, thereby generating each signal value of the detection target signal Bi. The storage unit 33 also includes data indicating a method for adjusting the signal value of the capacitance distribution signal Ai in the signal value adjusting unit 32 (in other words, data indicating a method for calculating the signal value of the detection target signal Bi in the sense signal processing unit 30; (Hereinafter referred to as “calibration data”) is temporarily stored.

  The detection target signal Bi is a signal that indicates the presence or absence of an indicator that is in contact with or close to each position on the detection surface P by the magnitude of each signal value corresponding to each position on the detection surface P. Specifically, the detection target signal Bi generated in the touch panel system 1 illustrated in FIG. 1 is a signal indicating the in-plane distribution of capacitance formed by the drive line DL and the sense line SL.

  The indicator position detection unit 40 detects the position of the indicator that is in contact with or close to the detection surface P based on the detection target signal Bi, and generates a detection result signal Ti indicating the detection result. Specifically, the pointer position detection unit 40 detects the position in the detection surface P where the capacitance is fluctuating with respect to the in-plane distribution of the capacitance represented by each signal value of the detection target signal Bi. Detect body position.

  The detection result signal Ti may include the number of detected indicators, the position of each indicator, data indicating the degree of contact or proximity of each indicator to the detection surface P, and the like. And this detection result signal Ti is utilized as a signal which shows a user's instruction | indication in electronic information equipment provided with the touch panel system 1, for example.

  The control unit 50 controls the operations of the drive line driving unit 20, the sense signal processing unit 30, and the indicator position detection unit 40, respectively. In particular, the control unit 50 monitors whether or not the operation of the sense signal processing unit 30 (particularly, calibration described later) has been executed normally (details will be described later).

  In FIG. 1, the storage unit 33 is shown as a part of the sense signal processing unit 30, but the data stored in the storage unit 33 is not limited to data related to the operation of the sense signal processing unit 30. . For example, when the indicator position detection unit 40 detects the current indicator position using the past indicator position in addition to the detection target signal Bi, data indicating the movement speed and direction of the indicator Is included in the detection result signal Ti, the storage unit 33 temporarily stores the data indicating the position of the indicator detected by the indicator position detection unit 40 in the past (for example, the latest) and indicates the data. You may give with respect to the body position detection part 40. FIG. Further, in FIG. 1, the pointer position detection unit 40 and the control unit 50 are illustrated as separate bodies, but the pointer position detection unit 40 may be a part of the control unit 50.

<Touch panel drive method and capacitance distribution signal generation method>
Next, a specific operation example of each part of the touch panel system 1 described above will be described with reference to the drawings. First, a method for driving the touch panel 10 by the drive line driving unit 20 and a method for generating the capacitance distribution signal Ai by the sense signal acquiring unit 31 will be described with reference to the drawings. In the following, for the sake of concrete explanation, a case where the drive line driving unit 20 drives the touch panel 10 in an orthogonal parallel manner will be exemplified.

  The orthogonal parallel drive of the touch panel 10 will be described with reference to FIGS. FIG. 4 is a diagram illustrating orthogonal parallel driving of the touch panel. FIG. 5 is a diagram for explaining a method of decoding the capacity distribution signal when the touch panel is driven in orthogonal parallel. In FIG. 4, only one sense line SL1 and four drive lines DL1 to DL4 are shown for simplification of description. Also, the respective capacities formed by the sense line SL1 and the drive lines DL1 to DL4 are C11 to C41.

  As shown in the upper block diagram of FIG. 4, the sense signal acquisition unit 31 includes an amplification unit 311 and a capacitance signal generation unit 312. The amplifying unit 311 has an inverting input terminal (−) to which the sense line SL1 is connected and an output terminal connected via an amplification capacitor Cint, and an operational amplifier whose non-inverting input terminal (+) becomes a ground voltage (GND). It is constituted by. Further, the capacitance signal generation unit 312 obtains a conversion value Ct corresponding to the capacitances C11 to C41 by performing a predetermined calculation after AD (Analog to Digital) conversion of the voltage value Vout of the output terminal of the amplification unit 311. The capacity distribution signal Ai is generated by decoding the conversion value Ct.

  Further, as shown in the lower table of FIG. 4, in the orthogonal parallel drive of the touch panel 10, the signal voltages “1” (positive voltage, + V) and “−1” (negative) are applied to the drive lines DL1 to DL4. Drive signal Di having a voltage of −V) as a component. In this example, the drive signal Di given to the drive lines DL1 to DL4 is repeated as the combination of “1” and “−1” fluctuates in the order shown in the lower table of FIG. (For example, the first time, the second time, the third time, the fourth time, the first time, the second time,...).

  In the orthogonal parallel driving, positive or negative charges are accumulated in each of the drive lines DL1 to DL4 by driving the drive lines DL1 to DL4. Therefore, a sense signal Si having a voltage value corresponding to a value obtained by adding or subtracting all the capacitors C11 to C41 appears on the sense line SL1, and the voltage value Vout of the output terminal of the amplifying unit 311 is also represented by the capacitors C11 to C11. It becomes a value corresponding to a value obtained by adding or subtracting C41.

  Specifically, since “1” is given to all of the drive lines DL1 to DL4 in the first drive, the voltage value Vout of the output terminal of the amplifying unit 311 is Vout = (C11 + C21 + C31 + C41) · V / Cint. Become. At this time, since the voltage V and the amplification capacitance Cint are known, the capacitance signal generation unit 312 adds the capacitances C11 to C41 or simply performs a simple calculation on the voltage value Vout (multiply by Cint / V) or A converted value Ct obtained by subtraction can be obtained. In the first drive, when the capacitance signal generation unit 312 performs an operation, a conversion value Ct indicating C11 + C21 + C31 + C41 is obtained.

  In the second drive, “1” is given to the drive lines DL1 and DL3 and “−1” is given to the drive lines DL2 and DL4. Vout is Vout = (C11−C21 + C31−C41) · V / Cint. And the conversion value Ct which shows C11-C21 + C31-C41 is obtained by the calculation of the capacity | capacitance signal generation part 312. FIG.

  In the third drive, “1” is given to the drive lines DL1 and DL2, and “−1” is given to the drive lines DL3 and DL4. Therefore, the voltage value of the output terminal of the amplifying unit 311 Vout is Vout = (C11 + C21−C31−C41) · V / Cint. And the conversion value Ct which shows C11 + C21-C31-C41 is obtained by the calculation of the capacity | capacitance signal generation part 312. FIG.

  In the fourth drive, since “1” is given to the drive lines DL1 and DL4 and “−1” is given to the drive lines DL2 and DL3, the voltage value of the output terminal of the amplifier 311 Vout is Vout = (C11−C21−C31 + C41) · V / Cint. And the conversion value Ct which shows C11-C21-C31 + C41 is obtained by the calculation of the capacity | capacitance signal generation part 312. FIG.

  In order to obtain the respective capacitances C11 to C41 from the conversion value Ct obtained as described above, it is necessary to decode the conversion value Ct as shown in FIG. Note that FIG. 5 illustrates the case where the capacitors C11 to C44 formed by the four sense lines SL1 to SL4 and the drive lines DL1 to DL4 are respectively obtained, but the drive signal Di applied to the drive lines DL1 to DL4. Is the same as FIG.

  As shown in FIG. 5A, the capacitance formed by the sense line SL1 and the drive lines DL1 to DL4 is C11 to C41, and the capacitance formed by the sense line SL2 and the drive lines DL1 to DL4 is C12 to C42. The capacitors formed by the sense line SL3 and the drive lines DL1 to DL4 are C13 to C43, and the capacitors formed by the sense line SL4 and the drive lines DL1 to DL4 are C14 to C44. Further, the conversion value of the sense line SL1 in the first to fourth driving is Ct11 to Ct41, and the conversion value of the sense line SL2 in the first to fourth driving is Ct12 to Ct42, and the first to fourth driving. The conversion values of the sense line SL3 are Ct13 to Ct43, and the conversion values of the sense line SL4 during the first to fourth driving are Ct14 to Ct44.

  In this case, as shown in FIG. 5B, the matrix “Ct” of the converted values Ct11 to Ct44 is an inner product of the matrix “H” of the drive signal Di and the matrix “C” of the capacitors C11 to C44. The matrix “Ct” has sense lines SL1 to SL4 from which converted values are obtained as rows and the order in which the converted values are obtained as columns. The matrix “H” has drive lines DL1 to DL4 that supply components (signal voltages) of the drive signal Di as rows and columns in which the components of the drive signal Di are supplied. Further, the matrix “C” has the capacitance along the direction (X direction) in which the drive lines DL1 to DL4 extend as rows and the capacitance along the direction (Y direction) in which the sense lines SL1 to SL4 extend as columns. .

  Here, for the sake of concrete description, attention is paid to the sense line SL1 and the capacitors C11 to C41 shown in FIG. The following description is also valid for the other sense lines SL2 to SL4 and the capacitors C12 to C42, C13 to C43, and C14 to C44.

  Ct11 which is a component of the first row and first column of the inner products “H” and “C” in FIG. 5B is expressed by the following equation (1). Similarly, Ct21 which is a component in the second row and first column of the inner product “H” / “C” is Ct31 which is a component in the third row and first column of the inner product “H” / “C”. Is the following equation (3), and Ct41 which is the component of the fourth row and first column of the inner product “H” / “C” is the following equation (4).

Ct11 = C11 + C21 + C31 + C41 (1)
Ct21 = C11−C21 + C31−C41 (2)
Ct31 = C11 + C21-C31-C41 (3)
Ct41 = C11−C21−C31 + C41 (4)

In the orthogonal parallel drive, since the components “1” and “−1” of the drive signal Di given to the drive lines DL1 to DL4 are orthogonal sequences, the matrix “H” is an orthogonal matrix. Therefore, as shown in FIG. 5C, only the inner product of the transpose matrix (matrix in which the row components and the column components are exchanged) “H ^T ” and the matrix “Ct” of the drive signal matrix “H” is obtained. Thus, the matrix “C” (that is, the in-plane distribution of capacitance) can be obtained. In this example, the matrix “H ^T ” is equal to the matrix “H”.

Specifically, the calculation result of the first row and first column of the inner product “H ^T ” / “Ct” is expressed by the following equation (5). Similarly, the inner product "H ^T", the second row, first column of the operation result shown by the following formula "Ct" (6), and the inner product "H ^T ', third row operation result of the first column of the" Ct "is The following equation (7) is obtained, and the calculation result of the fourth row and first column of the inner product “H ^T ” / “Ct” is represented by the following equation (8). In addition, the right side of following formula (5)-(8) is calculated | required by substituting said formula (1)-(4) with respect to the left side of following formula (5)-(8), respectively.

Ct11 + Ct21 + Ct31 + Ct41 = 4 · C11 (5)
Ct11−Ct21 + Ct31−Ct41 = 4 · C21 (6)
Ct11 + Ct21−Ct31−Ct41 = 4 · C31 (7)
Ct11−Ct21−Ct31 + Ct41 = 4 · C41 (8)

In the orthogonal parallel drive, t times (4 in the example of FIG. 5) capacitances C11 to C41 are obtained by decoding processing (matrix operation) in the capacitance signal generation unit 312. Therefore, the influence of noise is t1 ^{/ 2} Reduced.

  The capacity distribution signal Ai generated as described above represents the magnitude of the capacity at each position on the detection surface P by the magnitude of each signal value. In particular, the capacitance distribution signal Ai generated by the above method has a corresponding signal value that decreases as the capacitance formed on the detection surface P increases. The same applies to the detection target signal Bi generated by adjusting the capacitance distribution signal Ai.

  By the way, as described above, the sense signal Si generated by the touch panel 10 has various influences such as structural variations of the touch panel 10, dirt attached to the detection surface P, deterioration over time, and use environment (particularly temperature). receive. The same applies to the capacitance distribution signal Ai obtained by processing the sense signal Si. For this reason, the signal values of the capacitance distribution signal Ai vary even in the non-instruction state, and are not uniform. Therefore, when the indicator is detected using the capacitance distribution signal Ai directly, the detection sensitivity of the indicator varies in the detection plane P.

  Therefore, in the touch panel system 1 according to the embodiment of the present invention, a calibration method described below is executed to determine a method for adjusting the signal value of the capacitance distribution signal Ai (a method for calculating the signal value of the detection target signal Bi). To do. Then, the signal value adjustment unit 32 generates the detection target signal Bi based on the determined signal value adjustment method of the capacitance distribution signal Ai (the calculation method of the signal value of the detection target signal Bi). Variation in the detection sensitivity of the indicator due to various influences is suppressed.

<Calibration execution>
Next, calibration in the signal value adjustment unit 32 of the sense signal processing unit 30 will be described with reference to the drawings.

  FIG. 6 is a graph showing each of the capacitance distribution signal, the calibration data, and the detection target signal. FIG. 6A is a graph showing the capacity distribution signal Ai. FIG. 6B is a graph showing the calibration data. FIG. 6C is a graph showing the detection target signal Bi. Further, the capacity distribution signal Ai, the calibration data, and the detection target signal Bi shown in FIGS. 6A to 6C are each generated in a non-instruction state.

  As shown in FIG. 6A, the signal values of the capacitance distribution signal Ai are non-uniform because they vary even in the non-instruction state as described above.

  Therefore, the signal value adjustment unit 32 determines an adjustment method for suppressing variations in signal values of the capacitance distribution signal Ai by executing calibration. Specifically, the signal value adjustment unit 32 adjusts the signal value of the capacitance distribution signal Ai so that each signal value of the detection target signal Bi generated in the non-instruction state becomes a reference value that is a predetermined value ( Calibration data) is determined. In the following, a case where the reference value is “0” is illustrated for the sake of concrete explanation.

  For example, the signal value adjustment unit 32 generates calibration data for setting each signal value of the capacitance distribution signal Ai shown in FIG. Specifically, as shown in FIG. 6B, the signal value adjusting unit 32 is a value obtained by inverting each signal value of the capacitance distribution signal Ai in FIG. 6A with respect to the reference value (ie, reference value-signal). Value) is generated.

  Then, the signal value adjustment unit 32 calculates the signal value of the detection target signal Bi by adjusting the signal value of the capacitance distribution signal Ai acquired after the calibration is performed using the calibration data. Specifically, the signal value adjustment unit 32 calculates each signal value of the detection target signal Bi by adding each value of the corresponding calibration data to each signal value of the capacitance distribution signal Ai. Each signal value of the detection target signal Bi calculated in this way is uniform because it becomes a reference value (or a value approximate to the reference value) as shown in FIG. .

  Here, the detection target signal Bi generated when the indicator contacts the detection surface P will be described with reference to the drawings. FIG. 7 is a graph showing a detection target signal generated when an indicator contacts the detection surface. FIG. 7A is a graph showing a detection target signal Bi generated when a finger touches the detection surface P. FIG. FIG. 7B is a graph showing a detection target signal Bi generated when the stylus pen contacts the detection surface P.

  As shown in FIGS. 7A and 7B, when the indicator (finger, stylus pen) contacts the detection surface P, the signal value of the detection target signal Bi corresponding to the contact position is the reference value. In comparison, it becomes significantly larger. On the other hand, the signal value of the detection target signal Bi corresponding to the other position of the detection surface P remains the reference value (or a value approximated to the reference value).

  As described above, when the calibration is performed, when the indicator contacts or approaches the detection surface P, the signal value corresponding to the contact position is significantly different from the signal value corresponding to the other position. Bi can be generated. Therefore, the indicator position detection unit 40 can detect the indicator with high accuracy by detecting the indicator using the detection target signal Bi.

  Further, as shown in FIGS. 7A and 7B, the increase amount (the decrease amount of the capacity) of the detection target signal Bi when the finger is in contact with the detection surface P is reduced on the detection surface P. It becomes larger than the amount of increase (the amount of decrease in the capacity) of the signal value of the detection target signal Bi when the stylus pen comes into contact. For example, in the example shown in FIG. 7A and FIG. 7B, the increase amount (capacity decrease amount) of the detection target signal Bi when the finger touches the detection surface P is the detection surface P. The amount of increase in the signal value of the detection target signal Bi when the stylus pen is in contact (the amount of decrease in the capacity) is increased to about 10 times.

<Calibration failure>
As described above, in order to make the signal value of the detection target signal Bi in the non-instruction state uniform, it is necessary to execute the calibration in the non-instruction state. When performing calibration, if there is an indicator in contact with or close to the detection surface P, the signal value adjustment unit 32 cancels the influence of the indicator in contact with or close to the detection surface P. Since the adjustment method of each signal value of the capacitance distribution signal Ai is determined, the calibration fails.

  Here, the detection target signal generated after the calibration fails will be described with reference to the drawings. FIG. 8 is a graph showing a detection target signal generated after calibration fails. FIG. 8A is a graph showing a detection target signal Bi generated after calibration fails by executing calibration while a finger is in contact with the detection surface P. FIG. FIG. 8B is a graph showing the detection target signal Bi generated after the calibration has failed due to the calibration being performed in a state where the stylus pen is in contact with the detection surface P. Each graph shown in FIGS. 8A and 8B shows the detection target signal Bi generated in the non-instruction state.

  As shown in FIG. 8A and FIG. 8B, when calibration is executed, if a pointer (finger, stylus pen) is in contact with the detection surface P, a detection target generated thereafter In the signal Bi, the signal value corresponding to the contact position is significantly smaller than the reference value. At this time, the decrease amount of the signal value of the detection target signal Bi corresponding to the contact position is an increase amount when the indicator (finger, stylus pen) contacts the detection surface P (FIG. 7A and FIG. 7). b))).

  Further, as shown in FIGS. 8A and 8B, the signal value corresponding to the contact position of the detection target signal Bi generated after the calibration is executed in a state where the finger is in contact with the detection surface P. Is smaller than the signal value corresponding to the contact position of the detection target signal Bi generated after calibration is performed in a state where the stylus pen is in contact with the detection surface P. For example, in the example shown in FIGS. 8A and 8B, it corresponds to the contact position of the detection target signal Bi generated after calibration is performed in a state where the finger is in contact with the detection surface P. The signal value is as small as about 10 times the signal value corresponding to the contact position of the detection target signal Bi generated after calibration is performed in a state where the stylus pen is in contact with the detection surface P.

  When the signal value adjustment unit 32 generates the detection target signal Bi as shown in FIGS. 8A and 8B, the position of the detection surface P corresponding to a signal value significantly smaller than the reference value ( Even if the indicator is in contact with or close to the position at which the indicator is in contact with the calibration when executing calibration, the signal value adjustment unit 32 adjusts the signal value corresponding to the position to be small. It is unlikely to become significantly larger than the reference value. For this reason, the detection sensitivity of the indicator is remarkably lowered at the position on the detection surface P, and in some cases, it is impossible to detect the indicator.

  Therefore, in the touch panel system 1 according to the embodiment of the present invention, as described below, the control unit 50 determines whether or not there is a calibration failure.

<Method for determining calibration failure>
A method for determining a calibration failure by the control unit 50 will be described with reference to the drawings. FIG. 9 is a graph showing threshold values used for determining the presence or absence of calibration failure.

  As shown in FIGS. 7A and 7B, when an indicator (finger, stylus pen) contacts or approaches the detection surface P, at least one signal value in the detection target signal Bi is greater than the reference value. Is also significantly larger. On the other hand, as shown in FIGS. 8A and 8B, if the calibration fails, at least one signal value of the detection target signal Bi becomes significantly smaller than the reference value.

  Therefore, as shown in FIG. 9, when the signal value of the detection target signal Bi falls below a predetermined threshold (calibration failure detection threshold: the third threshold Th3 and the fourth threshold Th4), It is determined that there has been a calibration failure. On the other hand, when the signal value of the detection target signal Bi exceeds a predetermined threshold (indicator detection threshold: the first threshold Th1 and the second threshold Th2), the control unit 50 indicates the indicator (finger) on the detection surface P. , Stylus pen) is determined to have been touched. However, the reference value is a value between the calibration failure detection threshold and the pointer detection threshold.

  In addition, as shown in FIGS. 7A, 7B, 8A, and 8B, detection is performed according to an indicator (finger, stylus pen) that contacts the detection surface P. The increase amount and the decrease amount of the signal value of the target signal Bi are different. Therefore, it is preferable that thresholds corresponding to the types of indicators that can be used in the touch panel system 1 are set.

  In the example illustrated in FIG. 9, for the finger, the third threshold Th <b> 3 is set as the calibration failure detection threshold, and the first threshold Th <b> 1 is set as the pointer detection threshold. In this case, when the signal value of the detection target signal Bi exceeds the first threshold value Th1 (when the distance from the reference value exceeds the first threshold value Th1), the control unit 50 determines that the finger has touched the detection surface P. judge. Further, when the signal value of the detection target signal Bi is lower than the third threshold Th3 (when the signal is separated from the reference value and exceeds the third threshold Th3), the control unit 50 moves the finger to the detection plane P when performing calibration. It is determined that the calibration has failed due to being in contact.

  In the example shown in FIG. 9, for the stylus pen, the fourth threshold Th4 is set as the calibration failure detection threshold, and the second threshold Th2 is set as the pointer detection threshold. In this case, the control unit 50 makes contact with the detection surface P when the signal value of the detection target signal Bi exceeds the second threshold Th2 (away from the reference value and exceeds the second threshold Th2). Is determined. Furthermore, when the signal value of the detection target signal Bi is lower than the fourth threshold Th4 (when the signal is separated from the reference value and exceeds the fourth threshold Th4), the control unit 50 detects the stylus pen when the calibration is performed. It is determined that the calibration has failed due to being in contact with P.

  However, the second threshold Th2 is a value between the first threshold Th1 and the reference value. The fourth threshold value is a value between the third threshold value Th3 and the reference value. Furthermore, the first threshold value Th1 and the third threshold value Th3 are set so that, for example, the average value thereof becomes the reference value. Similarly, the second threshold value Th2 and the fourth threshold value Th4 are set so that, for example, the average value thereof becomes the reference value.

  As described above, when the indicator detection threshold value and the calibration failure detection threshold value are set, it is possible to separately determine the detection of the indicator in contact with the detection surface P and the presence or absence of the calibration failure. Become. Note that, similarly to the control unit 50, the pointer position detection unit 40 may detect the pointer using the above-described pointer detection thresholds (first threshold Th1 and second threshold Th2).

  Here, a specific example of a calibration failure determination method by the control unit 50 will be described with reference to the drawings. FIG. 10 is a table showing the signal value distribution of the detection target signal when the indicator is a finger. FIG. 10A is a table showing a distribution of signal values of the detection target signal Bi generated with the finger in contact with the detection surface P after successful calibration. FIG. 10B is a table showing a distribution of signal values of the detection target signal Bi generated in the non-instruction state after the calibration is failed because the calibration is executed in a state where the finger is in contact with the detection surface P. It is. As described above, each signal value of the detection target signal Bi has a two-dimensional distribution corresponding to each position on the detection surface P. However, due to space limitations, in FIGS. 10A and 10B, the distribution of signal values corresponding to the respective positions in the X direction (alignment direction of the sense lines SL) of the detection surface P is discarded, and Y Only the distribution of signal values corresponding to each position in the direction (alignment direction of the drive lines DL) is shown. The numerical values in the table indicate the number of signal values of the detection target signal Bi that satisfy the conditions in the leftmost column.

  First, the control unit 50 makes a determination based on the relationship between the signal value of the detection target signal Bi and the first threshold Th1 and the third threshold Th3. In the example shown in FIG. 10A, some signal values of the detection target signal Bi exceed the first threshold Th1 (signal values corresponding to the 25th to 27th positions of the drive line DL). . On the other hand, in the example shown in FIG. 10A, none of the signal values of the detection target signal Bi is lower than the third threshold Th3. In this case, the control unit 50 determines that the calibration is successful and that the finger is in contact with the detection surface P.

  On the other hand, in the example shown in FIG. 10B, none of the signal values of the detection target signal Bi exceed the first threshold Th1. On the other hand, in the example shown in FIG. 10B, some of the signal values of the detection target signal Bi are below the third threshold Th3 (signal values corresponding to the 25th to 27th positions of the drive line DL). ). In this case, the control unit 50 determines that the calibration has failed because the calibration is executed with the finger in contact with the detection surface P.

  FIG. 11 is a table showing the signal value distribution of the detection target signal when the indicator is a stylus pen. FIG. 11A is a table showing a distribution of signal values of the detection target signal Bi generated with the stylus pen in contact with the detection surface P after successful calibration. FIG. 11B shows a distribution of signal values of the detection target signal Bi generated in the non-instruction state after the calibration is failed because the calibration is executed in a state where the stylus pen is in contact with the detection surface P. It is a table. Note that the tables shown in FIGS. 11A and 11B represent the distribution of signal values of the detection target signal Bi in the same manner as the tables shown in FIGS. 10A and 10B. It is.

  First, the control unit 50 makes a determination based on the relationship between the signal value of the detection target signal Bi and the first threshold Th1 and the third threshold Th3. In the example shown in FIG. 11A, none of the signal values of the detection target signal Bi exceed the first threshold Th1. In addition, none of the signal values of the detection target signal Bi is less than the third threshold Th3. In this case, the control unit 50 determines that the calibration is not failed because the finger is not in contact with the detection surface P and the calibration is executed in a state where the finger is in contact with the detection surface P. In addition, the control part 50 performs the same determination also in the example shown in FIG.11 (b).

  Next, the control unit 50 makes a determination based on the relationship between the signal value of the detection target signal Bi and the second threshold Th2 and the fourth threshold Th4. In the example shown in FIG. 11A, some of the signal values of the detection target signal Bi exceed the second threshold Th2 (signal values corresponding to the 25th position of the drive line DL). On the other hand, in the example shown in FIG. 11A, none of the signal values of the detection target signal Bi is lower than the fourth threshold Th4. In this case, the control unit 50 determines that the calibration is successful and that the stylus pen is in contact with the detection surface P.

  On the other hand, in the example shown in FIG. 11B, none of the signal values of the detection target signal Bi exceed the second threshold Th2. On the other hand, in the example shown in FIG. 11B, some signal values of the detection target signal Bi are below the fourth threshold Th4 (signal values corresponding to the 25th position of the drive line DL). . In this case, the control unit 50 determines that the calibration has failed because the calibration has been executed with the detection surface P in contact with the stylus pen.

  As shown in FIG. 10A, FIG. 10B, FIG. 11A, and FIG. 11B, the control unit 50 is opposite to the case where there is an indicator that contacts or is close to the detection surface P. If each signal value of the detection target signal Bi has the above characteristic, it is determined that the calibration has failed. Therefore, it is possible to accurately detect the case where the calibration has failed, in distinction from the case where the indicator contacts or approaches the detection surface P.

  Further, as shown in FIGS. 11A and 11B, the control unit 50 has no signal value of the detection target signal Bi exceeding the first threshold Th1, and the third threshold value. When none of the values falls below Th3, it is determined whether there is something above the second threshold Th2 or whether there is something below the fourth threshold. That is, the control unit 50 first performs a determination on a finger that is an indicator that has a large influence on the signal value of the detection target signal Bi, and a stylus pen that is an indicator that has a small influence on the signal value of the detection target signal Bi. The determination regarding will be executed later. When the control unit 50 performs the determination in this order, it is possible to accurately distinguish the variation in the detection target signal Bi signal value caused by the stylus pen from the variation in the detection target signal Bi signal value caused by the finger. Therefore, it is preferable.

  As described above, the touch panel system 1 according to the embodiment of the present invention determines the presence / absence of calibration failure based on the detection target signal Bi used for detection of the indicator, so that the calibration can be performed with a simple structure. It is possible to determine whether or not there is a failure.

  By the way, in the example shown in FIGS. 10A, 10B, 11A, and 11B, each signal value of the detection target signal is obtained when the indicator contacts the detection surface P. If it has a feature, it does not have a feature when calibration fails. Further, in these examples, when each signal value of the detection target signal has a characteristic when the calibration fails, it does not have a characteristic when the indicator contacts the detection surface P.

  However, depending on the case, each signal value of the detection target signal Bi may have both a feature when the indicator is in contact with or close to the detection surface P and a feature when the calibration fails. is there. A method for determining a calibration failure in consideration of such a case will be described with reference to the drawings. FIG. 12 is a table showing a distribution of signal values of detection target signals generated in a state where the palm is in contact with the detection surface after successful calibration. Note that the table shown in FIG. 12 represents the distribution of signal values of the detection target signal Bi in the same manner as the tables shown in FIGS. 10 (a) and 10 (b).

  As shown in FIG. 12, when a continuous indicator (human body) such as a palm touches the detection surface P simultaneously and over a wide area, the first threshold Th1 is set in each signal value of the detection target signal Bi. Both above and below the third threshold Th3 are included.

  The reason why each signal value of the detection target signal Bi has the characteristics shown in the table of FIG. 12 will be described with reference to the drawings. FIG. 13 is a circuit diagram showing the capacitance formed when the indicator contacts a plurality of positions close to the detection surface. FIG. 13A is a circuit diagram showing the capacitance formed when the fingers of the left and right hands touch the detection surface P at the same time. FIG. 13B is a circuit diagram showing the capacitance formed when the palm touches the detection surface P.

  As shown in FIG. 13A, when discontinuous indicators such as fingers of the left and right hands are in contact with the detection surface P, for example, each finger acts as an independent shield (FIG. 3). (See (b)). Therefore, the sense signal Si indicating that the capacitance formed at each contact position (intersection of drive line DL1 and sense line SL1, intersection of drive line DL4 and sense line SL4) has been reduced is output. In such a case, each signal value of the detection target signal Bi does not have the characteristics shown in the table of FIG.

  On the other hand, as shown in FIG. 13B, when the continuous indicator called palm touches the detection surface P simultaneously and over a wide range, the respective contact positions (intersections of the drive line DL1 and the sense line SL1, drive) The intersection of the line DL4 and the sense line SL4) is electrically connected by a high-resistance indicator to form a floating node. At this time, when the drive signal Di having the same potential is applied to the drive lines DL1 and DL4 at the contact position and the voltage of the floating node changes, the intensity of the sense signal Si in the sense lines SL1 and SL4 passing through the contact position changes simultaneously. To do. As a result, among the capacitances formed by the drive lines DL1 and DL4 and the sense lines SL1 and SL4 that pass through the contact positions, the positions that are not the contact positions (intersections of the drive lines DL1 and the sense lines SL4, the drive lines DL4 and the sense lines SL1). A sense signal Si may be output as if the capacitance formed at (intersection) is increased. In such a case, each signal value of the detection target signal Bi has characteristics as shown in the table of FIG.

  Therefore, the control unit 50 sets the number of the detection target signal Bi below the calibration failure detection threshold (the third threshold Th3 and the fourth threshold Th4) and the indicator detection threshold (the first threshold Th1). Based on the comparison result of the number exceeding the second threshold value Th2), the presence or absence of a calibration failure is determined.

  Specifically, the control unit 50 determines that the number that is below the calibration failure detection threshold (the third threshold Th3 and the fourth threshold Th4) exceeds the indicator detection threshold (the first threshold Th1 and the second threshold Th2). If the number is larger than the number, it is determined that the calibration has failed.

  At this time, the controller 50 has exceeded the indicator detection threshold (the first threshold Th1 and the second threshold Th2) by the number below the calibration failure detection threshold (the third threshold Th3 and the fourth threshold Th4). If it is one or more than the number, it may be determined that the calibration has failed, or if the difference becomes a predetermined number of 2 or more, it may be determined that the calibration has failed. . In the latter case, the indicator detection threshold (the first threshold Th1 and the second threshold Th2) is less than the calibration failure detection threshold (the third threshold Th3 and the fourth threshold Th4) due to sudden noise or the like. Even if the number exceeds the number exceeding the number, it is possible to prevent the controller 50 from determining that the calibration has failed.

  In the example shown in FIG. 12, among the signal values of the detection target signal Bi, there are 42 signals that are below the third threshold Th3. On the other hand, in the example shown in FIG. 12, there are 433 that exceed the first threshold Th1. In this case, for each signal value of the detection target signal Bi, the number that is below the third threshold Th3 is equal to or less than the number that is above the first threshold Th1, so that the control unit 50 has succeeded in calibration, It is determined that the finger is in contact with the detection surface P.

  A further specific example of the calibration failure determination method performed by the control unit 50 will be described with reference to the drawings. FIG. 14 is a table showing the signal value distribution of the detection target signal when the indicator is a palm or a plurality of fingers. FIG. 15 is a graph showing in-plane distributions of signal values of detection target signals corresponding to the respective tables shown in FIG. FIG. 14A is a table showing a distribution of signal values of the detection target signal Bi generated in the non-instruction state after the calibration is failed because the calibration is executed in a state where the palm is in contact with the detection surface P. It is. FIG. 14B shows a distribution of signal values of the detection target signal Bi generated in the non-instruction state after the calibration has failed because the calibration is executed in a state where four fingers are in contact with the detection surface P. It is a table | surface which shows. FIG. 14C shows the distribution of signal values of the detection target signal Bi generated in the non-instruction state after the calibration has failed because the calibration is executed in a state where two fingers are in contact with the detection surface P. It is a table | surface which shows. Note that the tables shown in FIGS. 14A to 14C represent the distribution of signal values of the detection target signal Bi in the same manner as the tables shown in FIGS. 10A and 10B. It is. FIG. 15A is a graph showing the in-plane distribution of signal values of the detection target signal Bi corresponding to the table of FIG. FIG. 15B is a graph showing the in-plane distribution of signal values of the detection target signal Bi corresponding to the table of FIG. FIG. 15C is a graph showing the in-plane distribution of the signal value of the detection target signal Bi corresponding to the table of FIG. In the graphs shown in FIGS. 15A to 15C, the magnitude of the signal value of the outgoing signal Bi is represented by color shading (the signal value is larger as it is closer to white).

  First, the control unit 50 makes a determination based on the relationship between the signal value of the detection target signal Bi and the first threshold Th1 and the third threshold Th3. In the example shown in FIG. 14A, among the signal values of the detection target signal Bi, 330 are less than the third threshold Th3. On the other hand, in the example shown in FIG. 14A, among the signal values of the detection target signal Bi, there are 93 that exceed the first threshold Th1. In this case, for each signal value of the detection target signal Bi, the number that is below the third threshold Th3 is greater than the number that is above the first threshold Th1, so the control unit 50 makes a finger contact with the detection surface P. It is determined that the calibration has failed because the calibration has been executed in the state.

  Similarly, in the example illustrated in FIG. 14B, 174 of the signal values of the detection target signal Bi are below the third threshold Th3. On the other hand, in the example shown in FIG. 14B, 17 of the signal values of the detection target signal Bi exceed the first threshold value Th1. In this case, for each signal value of the detection target signal Bi, the number that is below the third threshold Th3 is greater than the number that is above the first threshold Th1, so the control unit 50 makes a finger contact with the detection surface P. It is determined that the calibration has failed because the calibration has been executed in the state.

  Similarly, in the example shown in FIG. 14C, among the signal values of the detection target signal Bi, 91 are less than the third threshold Th3. On the other hand, in the example shown in FIG. 14C, among the signal values of the detection target signal Bi, there are no signals that exceed the first threshold Th1. In this case, for each signal value of the detection target signal Bi, the number that is below the third threshold Th3 is greater than the number that is above the first threshold Th1, so the control unit 50 makes a finger contact with the detection surface P. It is determined that the calibration has failed because the calibration has been executed in the state.

  As described above, when the control unit 50 determines whether or not the calibration has failed, each signal value of the detection target signal Bi is characteristic when the indicator is in contact with or close to the detection surface P, and when the calibration has failed. It is possible to accurately determine that the calibration has failed even in the case of having both of these features. Further, the control unit 50 simply compares the number of signal values having characteristics when the calibration has failed with the number of signal values having characteristics when the indicator is in contact with or close to the detection surface P. Thus, it is possible to easily determine the presence or absence of a calibration failure.

  Further, when the number of signals that are lower than the third threshold Th3 and the number that exceeds the first threshold Th1 are both 0 for each signal value of the detection target signal Bi, the control unit 50 determines that the value of FIG. And the presence or absence of the failure of a calibration is determined by the method similar to the case shown in FIG.11 (b). That is, the control unit 50 determines the presence or absence of a calibration failure based on the relationship between the signal value of the detection target signal Bi and the second threshold Th2 and the fourth threshold Th4.

  Specifically, for each signal value of the detection target signal Bi, the control unit 50 has both the number that is below the third threshold Th3 and the number that is above the first threshold Th1 being zero, and the fourth If the number below the threshold Th4 is greater than the number above the second threshold Th2, it is determined that the calibration has failed because the calibration has been executed with the stylus pen in contact with the detection surface P. A situation in which such a determination is necessary is, for example, a case where calibration is performed in a state where the stylus pen and a finger having the stylus are simultaneously in contact with the detection surface P.

  As described above, when the control unit 50 determines whether there is a calibration failure, the control unit 50 determines whether there is a calibration failure corresponding to each indicator even when there are a plurality of types of the indicators used. Can be determined.

<Operation example of control unit>
[First operation example]
Next, an operation example of the control unit 50 will be described with reference to the drawings. First, a first operation example of the control unit 50 will be described with reference to the drawings. FIG. 16 is a flowchart illustrating a first operation example of the control unit.

  As shown in FIG. 16, the control unit 50 first acquires a detection target signal Bi for one frame (detection target signal Bi including one set of signal values corresponding to each position of the detection plane P) (step S1). # 1).

  At this time, for example, when the electronic information device provided with the touch panel system 1 is started up or returned from the sleep state, the control unit 50 is the first to acquire the detection target signal Bi (the calibration data is stored in the storage unit 33). If not stored (step # 2, YES), the control unit 50 controls the signal value adjustment unit 32 to execute calibration (step # 3). As a result, the calibration data generated by the signal value adjustment unit 32 is stored in the storage unit 33. Then, the control unit 50 acquires the detection target signal Bi for the next frame (step # 1).

  On the other hand, when it is not the first time to acquire the detection target signal Bi (step # 2, NO), the control unit 50 determines whether or not the above-described calibration has failed (step # 4).

  When the control unit 50 determines that the calibration is successful (step # 5, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and the detection result as a result thereof. The signal Ti is generated (step # 7). Then, the control unit 50 ends the operation when the operation is terminated in accordance with the user's instruction or the like (step # 8, YES), and when the operation is continued (step # 8, NO), the next frame is detected. The target signal Bi is acquired (step # 1).

  On the other hand, when the control unit 50 determines that the calibration has failed (step # 5, YES), the control unit 50 controls the signal value adjustment unit 32 to execute the calibration again (step # 9). As a result, the calibration data generated again by the signal value adjustment unit 32 is stored in the storage unit 33. Then, the control unit 50 acquires the detection target signal Bi for the next frame (step # 1).

  When the control unit 50 operates as described above, even if calibration fails, it is possible to improve the detection sensitivity of the indicator by performing calibration again.

[Second operation example]
Next, a second operation example of the control unit 50 will be described with reference to the drawings. FIG. 17 is a flowchart illustrating a second operation example of the control unit. Note that, in the second operation example of the control unit 50 described below, the same step numbers are assigned to the same operations as those in the first operation example, and the detailed description thereof is omitted.

  As shown in FIG. 17, the controller 50 first sets the counter variable E to 0 (step # A1). Next, the control unit 50 acquires the detection target signal Bi for one frame (step # 1). At this time, when the control unit 50 is the first time to acquire the detection target signal Bi (step # 2, YES), the control unit 50 controls the signal value adjustment unit 32 to execute calibration (step). # 3). Then, the control unit 50 acquires the detection target signal Bi for the next frame (step # 1).

  On the other hand, when it is not the first time to acquire the detection target signal Bi (step # 2, NO), the control unit 50 determines whether or not the calibration has failed (step # 4).

  When determining that the calibration is successful (step # 5, NO), the control unit 50 sets the counter variable E to 0 (step # A2). Further, the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and generates a detection result signal Ti as a result (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

  On the other hand, when determining that the calibration has failed (step # 5, YES), the control unit 50 adds one counter variable E (step # A3).

At this time, if the counter variable E has not reached the upper limit number E _MAX (step # A4, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6). ) And a detection result signal Ti as a result is generated (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

On the other hand, if the counter variable E has reached the upper limit number E _MAX (step # A4, YES), the control unit 50 controls the signal value adjustment unit 32 to execute calibration again (step #). 9). Then, the control unit 50 sets the counter variable E to 0 (step # A1), and acquires the detection target signal Bi of the next frame (step # 1).

  When the control unit 50 operates as described above, the calibration is performed again only when there is a high probability that the calibration has failed. Therefore, it is possible to prevent the processing speed from being reduced or the power consumption from being increased due to excessive execution of calibration.

[Third operation example]
Next, a third operation example of the control unit 50 will be described with reference to the drawings. FIG. 18 is a flowchart illustrating a third operation example of the control unit. Note that, in the third operation example of the control unit 50 described below, the same step numbers are assigned to the same operations as those in the first operation example and the second operation example, and detailed descriptions thereof are omitted.

  As shown in FIG. 18, the control unit 50 first sets a counter variable E to 0 (step # A1). Next, the control unit 50 acquires the detection target signal Bi for one frame (step # 1). At this time, when the control unit 50 is the first time to acquire the detection target signal Bi (step # 2, YES), the control unit 50 controls the signal value adjustment unit 32 to execute calibration (step). # 3). Then, the control unit 50 acquires the detection target signal Bi for the next frame (step # 1).

  On the other hand, when it is not the first time that the control unit 50 acquires the detection target signal Bi (step # 2, NO), the acquired detection target signal Bi is a predetermined number of frames in the frames that the control unit 50 sequentially acquires. Is confirmed (step # B1).

  If the acquired detection target signal Bi is not a confirmation target frame (step # B1, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6). A detection result signal Ti as a result is generated (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

  On the other hand, if the acquired detection target signal Bi is the confirmation target frame (step # B1, YES), the control unit 50 determines whether or not the calibration has failed (step # 4).

  When determining that the calibration is successful (step # 5, NO), the control unit 50 sets the counter variable E to 0 (step # A2). Further, the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and generates a detection result signal Ti as a result (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

  On the other hand, when determining that the calibration has failed (step # 5, YES), the control unit 50 adds one counter variable E (step # A3).

At this time, if the counter variable E has not reached the upper limit number E _MAX (step # A4, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6). ) And a detection result signal Ti as a result is generated (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

On the other hand, if the counter variable E has reached the upper limit number E _MAX (step # A4, YES), the control unit 50 controls the signal value adjustment unit 32 to execute calibration again (step #). 9). Then, the control unit 50 sets the counter variable E to 0 (step # A1), and acquires the detection target signal Bi of the next frame (step # 1).

  When the control unit 50 operates as described above, it is possible to suppress the frequency of executing the determination of whether or not the calibration has failed, thereby preventing the processing speed from being reduced or the power consumption from being increased. Is possible.

  In the third operation example of the control unit 50 described above, steps # A1 to # A4 need not be executed. In this case, the control unit 50 acquires the detection target signal Bi for one frame without setting the counter variable E to 0 (step # 1). If the control unit 50 determines that the calibration is successful (step # 5, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and the calibration fails. If it is determined that it has been performed (step # 5, YES), the signal value adjustment unit 32 is controlled to execute calibration again (step # 9).

[Fourth operation example]
Next, a fourth operation example of the control unit 50 will be described with reference to the drawings. FIG. 19 is a flowchart illustrating a fourth operation example of the control unit. Note that, in the fourth operation example of the control unit 50 described below, the same step numbers are assigned to the same operations as those in the first operation example to the third operation example, and the detailed description thereof is omitted.

  As shown in FIG. 19, the controller 50 first sets a counter variable E to 0 (step # A1). Next, the control unit 50 acquires the detection target signal Bi for one frame (step # 1). At this time, when the control unit 50 is the first time to acquire the detection target signal Bi (step # 2, YES), the control unit 50 controls the signal value adjustment unit 32 to execute calibration (step). # 3). Then, the control unit 50 acquires the detection target signal Bi for the next frame (step # 1).

  On the other hand, when it is not the first time that the control unit 50 acquires the detection target signal Bi (step # 2, NO), the control unit 50 starts the operation of the touch panel system 1 (the sense signal processing unit 30 performs the operation). It is checked whether or not it is during the start-up period, which is a period from when the detection target signal Bi is started to be generated until the detection target signal Bi of a predetermined number of frames is generated (step # C1).

  When it is not during the starting period (step # C1, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and the detection result signal Ti that is the result thereof. Is generated (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

  On the other hand, if it is during the start-up period (step # C1, YES), the control unit 50 checks whether or not the acquired detection target signal Bi is a confirmation target frame (step # B1).

  If the acquired detection target signal Bi is not a confirmation target frame (step # B1, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6). A detection result signal Ti as a result is generated (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

  On the other hand, if the acquired detection target signal Bi is the confirmation target frame (step # B1, YES), the control unit 50 determines whether or not the calibration has failed (step # 4).

  When determining that the calibration is successful (step # 5, NO), the control unit 50 sets the counter variable E to 0 (step # A2). Further, the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and generates a detection result signal Ti as a result (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

  On the other hand, when determining that the calibration has failed (step # 5, YES), the control unit 50 adds one counter variable E (step # A3).

At this time, if the counter variable E has not reached the upper limit number E _MAX (step # A4, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6). ) And a detection result signal Ti as a result is generated (step # 7). Then, the control unit 50 ends the operation when the operation is ended (step # 8, YES), and acquires the detection target signal Bi of the next frame when the operation is continued (step # 8, NO). (Step # 1).

On the other hand, if the counter variable E has reached the upper limit number E _MAX (step # A4, YES), the control unit 50 controls the signal value adjustment unit 32 to execute calibration again (step #). 9). Then, the control unit 50 sets the counter variable E to 0 (step # A1), and acquires the detection target signal Bi of the next frame (step # 1).

  In the touch panel system 1, a calibration failure is detected by the control unit 50 when the indicator that is in contact with or close to the detection surface P at the time of executing the calibration in step # 3 is subsequently separated from the detection surface P. The The separation of the indicator from the detection surface P is highly likely to occur within a predetermined period from the time of execution of calibration in step # 3. In other words, the start period is a period in which there is a high probability that a calibration failure is detected when the calibration fails, so it can be said that it is highly necessary to determine whether or not the calibration has failed.

  Therefore, when the control unit 50 operates as described above, it is possible to determine the presence or absence of the calibration failure only in the start-up period in which the necessity of determining the presence or absence of the calibration failure is high. For this reason, it is possible to prevent the processing speed from being lowered or the power consumption from being increased by determining whether or not the calibration has failed forever after the execution of calibration.

  In the above-described fourth operation example, a period from when the touch panel system 1 starts operating until the detection target signal Bi for a predetermined number of frames is generated (the presence or absence of the failure of calibration in step # 3 is determined). The period during which the necessity is high) is the start period. However, considering not only step # 3 but also the possibility that the calibration of step # 9 may fail, until the detection target signal Bi of a predetermined number of frames is generated after the calibration is executed. This period (a period during which it is highly necessary to determine whether or not the calibration in steps # 3 and # 9 has failed) may be used as the start-up period.

  In the fourth operation example of the control unit 50 described above, steps # A1 to # A4 may not be executed. In this case, the control unit 50 acquires the detection target signal Bi for one frame without setting the counter variable E to 0 (step # 1). If the control unit 50 determines that the calibration is successful (step # 5, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and the calibration fails. If it is determined that it has been performed (step # 5, YES), the signal value adjustment unit 32 is controlled to execute calibration again (step # 9).

  Further, in the fourth operation example of the control unit 50 described above, step # B1 may not be executed. In this case, if it is not during the start period (step # C1, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and is during the start period. If so (step # C1, YES), it is determined whether or not there is a calibration failure (step # 4).

  In the fourth operation example of the control unit 50 described above, steps # A1 to # A4 and step # B1 may not be executed. In this case, the control unit 50 acquires the detection target signal Bi for one frame without setting the counter variable E to 0 (step # 1). If the control unit 50 determines that the calibration is successful (step # 5, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and the calibration fails. If it is determined that it has been performed (step # 5, YES), the signal value adjustment unit 32 is controlled to execute calibration again (step # 9). Furthermore, when the control unit 50 is not in the startup period (step # C1, NO), the control unit 50 controls the pointer position detection unit 40 to execute detection of the pointer (step # 6), and is in the startup period. (Step # C1, YES), it is determined whether or not there is a calibration failure (Step # 4).

<< Electronic Information Equipment >>
A configuration example of an electronic information device according to an embodiment of the present invention that includes the touch panel system 1 described above will be described with reference to FIG. FIG. 20 is a block diagram illustrating a configuration example of the electronic information device according to the embodiment of the present invention.

  As illustrated in FIG. 20, the electronic information device 100 according to the embodiment of the present invention includes a display device 101, a display device control unit 102 that controls the display device 101, a touch panel 103 that corresponds to the touch panel 10 described above, and the above-described configuration. The touch panel controller 104 corresponding to each part (the drive line drive unit 20, the sense signal processing unit 30, the indicator position detection unit 40, and the control unit 50) except for the touch panel 10 in the touch panel system 1 is pressed by the user. A button switch unit 105 that accepts user instructions, an imaging unit 106 that generates image data by imaging, an audio output unit 107 that outputs input audio data as audio, and a sound collection unit that generates audio data by collecting sound 108 and processing of audio data given to the audio output unit 107 and A voice processing unit 109 that processes the voice data to be transmitted, a wireless communication unit 110 that wirelessly communicates communication data with a device external to the electronic information device 100, and communication data that the wireless communication unit 110 communicates wirelessly radiates as electromagnetic waves. In addition, an antenna 111 that receives an electromagnetic wave radiated from an external device of the electronic information device 100, a wired communication unit 112 that communicates communication data with the external device of the electronic information device 100 by wire, and a memory that stores various data 113 and a main body control unit 114 that controls the overall operation of the electronic information device 100.

  A part or all of the indicator position detection unit 40 and the control unit 50 described above may be a part of the main body control unit 114 instead of the touch panel controller 104. Similarly, the storage unit 33 described above may be a part of the memory 113 instead of the touch panel controller 104.

  Further, the electronic information device 100 illustrated in FIG. 20 is only one application example of the touch panel system 1. The touch panel system 1 described above is naturally applicable to an electronic information device having a configuration different from that of the electronic information device 100 illustrated in FIG.

<< Deformation, etc. >>
[1] In the above-described embodiment, the capacity distribution signal Ai and the detection target signal Bi are described as having a corresponding signal value that decreases as the capacitance formed on the detection surface P increases. However, the capacitance distribution signal Ai and the detection target signal Bi are not necessarily such signals. For example, the capacitance distribution signal Ai and the detection target signal Bi may be such that the corresponding signal value increases as the capacitance formed on the detection surface P increases.

[2] In FIGS. 4 and 5, the case where an orthogonal sequence is used as a component of the drive signal Di is illustrated, but an M sequence that is a pseudo-orthogonal sequence may be used. That is, the matrix “H” that is a component of the drive signal Di is applied with an M-sequence code having a code length N (= 2n−1) in the first row, and in the second and subsequent rows, the code is sequentially cyclically shifted every 1 bit. It is good also as what applied. Also in this case, the matrix “C” (that is, the in-plane distribution of capacity) can be obtained only by obtaining the inner product of the transposed matrix “H ^T ” of “H” and the matrix “Ct”. However, unlike the case of using an orthogonal sequence, an error is included in the inner product calculation result when an M sequence is used. However, by increasing the code length N such as N = 63 or 127, the degradation of the SN ratio is suppressed. It is possible.

[3] In the above-described embodiment, the case where the present invention is applied to the touch panel system 1 including the projected capacitive touch panel 10 has been described. However, the present invention can be applied to a touch panel system including a touch panel of another method as long as the touch panel system includes a touch panel that requires calibration.

<< Summary >>
The operation method of the touch panel system 1, the electronic information device 100, and the touch panel system 1 according to the embodiment of the present invention can be grasped as follows, for example.

  The touch panel system 1 according to the embodiment of the present invention includes a touch panel 10 that generates a sense signal Si having an intensity corresponding to the presence or absence of an indicator that is in contact with or close to each position on the detection surface P, and the sense that the touch panel 10 generates. By detecting the signal Si, the detection target signal that represents the presence or absence of the indicator that is in contact with or close to each position on the detection surface P by the magnitude of each signal value corresponding to each position on the detection surface P. A sense signal processing unit 30 that generates Bi; and a control unit 50 that monitors the operation of the sense signal processing unit 30, wherein the sense signal processing unit 30 generates the signal values of the detection target signal Bi to be generated. Performs a calibration for determining a calculation method of each signal value of the detection target signal Bi at a predetermined timing so that the reference value is a predetermined value. The control unit 50 is configured so that each signal value of the detection target signal Bi generated by the sense signal processing unit 30 after the calibration is performed has a predetermined characteristic. It is determined that the calibration has failed.

  According to this touch panel system 1, since it is possible to determine the presence or absence of a calibration failure based on the detection target signal Bi used for the detection of the indicator, the presence or absence of a calibration failure can be determined with a simple structure. It becomes possible to judge.

  Further, in the touch panel system 1, the reference value is a value between the indicator detection thresholds Th1 and Th2 and the calibration failure detection thresholds Th3 and Th4, and the detection surface of the detection target signal Bi When the signal value corresponding to a certain position of P is away from the reference value and exceeds the pointer detection thresholds Th1 and Th2, the pointer is in contact with or close to the certain position of the detection surface P. The control unit 50, when at least one of the signal values of the detection target signal Bi is away from the reference value and exceeds the calibration failure detection threshold Th3, Th4, It is determined that the calibration has failed.

  According to the touch panel system 1, the calibration fails when the control unit 50 has each signal value of the detection target signal Bi having a characteristic opposite to the case where there is an indicator that is in contact with or close to the detection surface P. It is determined that Therefore, it is possible to accurately detect the case where the calibration has failed, in distinction from the case where the indicator contacts or approaches the detection surface P.

  Further, in the touch panel system 1 described above, the control unit 50, for each signal value of the detection target signal Bi, is separated from the reference value and exceeds the calibration failure detection thresholds Th3 and Th4, Whether or not the calibration has failed is determined based on the comparison result between the reference value and the number exceeding the pointer detection thresholds Th1 and Th2.

  According to the touch panel system 1, each signal value of the detection target signal Bi has both a characteristic when the indicator is in contact with or close to the detection surface P and a characteristic when the calibration fails. Even in this case, it is possible to accurately determine that the calibration has failed.

  Furthermore, in the touch panel system 1 described above, the control unit 50 determines that the number of the signal values of the detection target signal Bi that is apart from the reference value and exceeds the calibration failure detection thresholds Th3 and Th4, It is determined that the calibration has failed when there is more than the number that exceeds the pointer detection thresholds Th1 and Th2 apart from the reference value.

  According to the touch panel system 1, the control unit 50 has the number of signal values having characteristics when the calibration fails, and the number of signal values having characteristics when the indicator is in contact with or close to the detection surface P. It is possible to easily determine the presence or absence of a calibration failure simply by comparing.

  Further, in the touch panel system 1 described above, a first threshold Th1 and a second threshold Th2 that is a value between the first threshold Th1 and the reference value are set as the indicator detection threshold. In addition, a third threshold Th3 and a fourth threshold Th4, which is a value between the third threshold and the reference value, are set as the calibration failure detection threshold. For each signal value of the detection target signal Bi, the number that is apart from the reference value and exceeds the third threshold Th3 is greater than the number that is apart from the reference value and exceeds the first threshold Th1 In addition, it is determined that the calibration has failed, and for each of the signal values of the detection target signal Bi, a number that is apart from the reference value and exceeds the third threshold Th3, and the base A number that is more than the first threshold value Th1 apart from the value is 0, and a number that is more than the fourth threshold value Th4 away from the reference value is more than the fourth value Th4 away from the reference value. If the number is greater than the number exceeding the threshold value Th2, it is determined that the calibration has failed.

  According to the touch panel system 1, even when there are a plurality of types of indicators used, the control unit 50 can determine whether or not calibration has failed according to each indicator.

  Further, in the touch panel system 1 described above, when the control unit 50 determines that the calibration has failed, the control unit 50 controls the sense signal processing unit 30 to execute the calibration again.

  According to this touch panel system 1, even if calibration fails, it is possible to improve the detection sensitivity of the indicator by performing calibration again.

  Further, in the touch panel system 1 described above, the control unit 50 controls the sense signal processing unit 30 and executes the calibration again when it is determined that the calibration has failed continuously for a predetermined number of times. Let

  According to the touch panel system 1, the calibration is executed again only when the probability that the calibration has failed is high. Therefore, it is possible to prevent the processing speed from being reduced or the power consumption from being increased due to excessive execution of calibration.

  Furthermore, in the touch panel system 1 described above, a period in which the sense signal processing unit 30 generates the detection target signal Bi including the signal values corresponding to the positions on the detection surface P is set to one frame. At this time, the control unit 50 determines whether or not the calibration has failed every predetermined number of frames.

  According to the touch panel system 1, it is possible to suppress the frequency of executing the determination of whether or not the calibration has failed, and thus it is possible to prevent the processing speed from being reduced and the power consumption from being increased. Become.

  Furthermore, in the touch panel system 1 described above, a period in which the sense signal processing unit 30 generates the detection target signal Bi including the signal values corresponding to the positions on the detection surface P is set to one frame. The controller 50 determines whether the calibration has failed after the sense signal processor 30 starts generating the detection target signal Bi and before generating a predetermined number of frames. .

  According to the touch panel system 1, it is possible to determine whether or not there is a calibration failure only in the start-up period in which it is highly necessary to determine whether or not there is a calibration failure. For this reason, it is possible to prevent the processing speed from being lowered or the power consumption from being increased by determining whether or not the calibration has failed forever after the execution of calibration.

  Further, in the touch panel system 1 described above, the touch panel 10 intersects the drive line DL with a plurality of drive lines DL provided parallel to each other along the detection surface P and given a predetermined voltage from the outside. A plurality of the sense lines SL provided in parallel to each other along the detection surface P to generate the sense signal Si, and the magnitude of each signal value of the detection target signal Bi is determined by the detection surface This corresponds to the capacitance of the drive line DL and the sense line SL at each position of P.

  According to the touch panel system 1, in the touch panel system 1 including the projected capacitive touch panel 10, the presence / absence of calibration failure is determined based on the detection target signal Bi used for detection of the indicator. Therefore, it is possible to determine the presence or absence of a calibration failure with a simple structure.

  Moreover, the electronic information device 100 according to the embodiment of the present invention includes the touch panel system 1 described above.

  In addition, the operation method of the touch panel system 1 according to the embodiment of the present invention processes the sense signal Si having an intensity corresponding to the presence or absence of an indicator that is in contact with or close to each position of the detection surface P of the touch panel 10 and performs the detection. A detection target signal generation operation for generating a detection target signal Bi that represents the presence or absence of the indicator that is in contact with or close to each position on the surface P by the magnitude of each signal value corresponding to each position on the detection surface P; A calibration for determining a calculation method of each signal value of the detection target signal Bi so that each signal value of the generated detection target signal Bi becomes a reference value that is a predetermined value. When the calibration operation executed at the timing and each signal value of the detection target signal Bi generated after the calibration is executed have predetermined characteristics And Calibration failure determination operation determines that the calibration fails, is executed

  The present invention can be suitably used for a touch panel system including a projection type touch panel, an electronic information device including the touch panel system, and an operation method of the touch panel system.

DESCRIPTION OF SYMBOLS 1: Touch panel system 10: Touch panel 20: Drive line drive part 30: Sense signal processing part 31: Sense signal acquisition part 32: Signal value adjustment part 33: Memory | storage part 40: Indicator position detection part 50: Control part 100: Electronic information Device DL: Drive line SL: Sense line P: Detection surface Di: Drive signal Si: Sense signal Ai: Capacity distribution signal Bi: Detection target signal

Claims (4)

A touch panel that generates a sense signal having an intensity corresponding to the presence or absence of an indicator that is in contact with or close to each position on the detection surface;
By processing the sense signal generated by the touch panel, the presence or absence of the indicator that is in contact with or close to each position on the detection surface is represented by the magnitude of each signal value corresponding to each position on the detection surface. A sense signal processing unit that generates the detected signal to be detected;
A control unit that monitors the operation of the sense signal processing unit,
The sense signal processing unit detects the detection value so that each signal value of the detection target signal to be generated becomes a reference value that is a predetermined value between a pointer detection threshold value and a calibration failure detection threshold value. The calibration for determining the calculation method of each signal value of the target signal is configured to be executed at a predetermined timing,
When a signal value corresponding to a position on the detection surface of the detection target signal is away from the reference value and exceeds the indicator detection threshold value, the detection target signal contacts or approaches the position on the detection surface. Indicating that there is a pointer,
The control unit is configured such that at least one of the signal values of the detection target signal generated by the sense signal processing unit after the calibration is performed exceeds the calibration failure detection threshold away from the reference value. A touch panel system that determines that the calibration has failed . The control unit, for each signal value of the detection target signal, is a number that is far from the reference value and exceeds the calibration failure detection threshold, and is far from the reference value and exceeds the indicator detection threshold. the touch panel system of claim 1, the number, on the basis of the comparison result, and judging the presence or absence of failure of the calibration is. 3. The touch panel system according to claim 1, wherein, when it is determined that the calibration has failed, the control unit controls the sense signal processing unit to execute the calibration again. 4. An electronic information device comprising the touch panel system according to any one of claims 1 to 3 .

Images