JP5132593B2 - Touch panel device - Google Patents

Description

  The present invention relates to a touch panel device that determines a multipoint touch on a touch panel in which two resistive films are stacked.

  As a touch panel device for determining a multi-point touch for the purpose of preventing malfunction due to a multi-point touch on a touch panel using a resistive film, for example, there are those disclosed in Patent Document 1 and Patent Document 2 . Such a conventional touch panel device includes an x-direction touch panel having a resistance film extending between a pair of opposed terminals, and a set of opposed faces in a direction orthogonal to the extending direction of the resistance film of the x-direction touch panel. The y-direction touch panel having a resistive film extending between the terminals is overlapped. However, when a plurality of points are touched on the touch panel, the touch panel device disclosed in Patent Document 1 is opposed to the two-layer touch panel. Using the phenomenon that the resistance value between the terminals at the position is lowered, and the measured resistance value between the opposing terminals of the touch panel is greatly different from the reference value, it is determined as a multi-point touch. On the other hand, in the touch panel device of Patent Document 2, when the resistance value between the terminals at the orthogonal positions provided on the two-layer touch panel is greatly different from the reference value held in advance, it is determined as a multi-point touch. It was.

JP-A-8-241161 JP-A-9-134253

  Since the conventional touch panel device is configured as described above, there is a problem in that a multi-point touch cannot be properly detected depending on the distance between touch points and the touch load. For example, the resistance value between opposing terminals used for multi-point touch determination in Patent Document 1 is the same value as the one-point touch state in the two-point touch state where the distance between the touch points is short, and thus is difficult to distinguish. Met. In addition, since the resistance value between the orthogonal terminals used for the multipoint touch determination in Patent Document 2 includes the contact resistance between the two layers of resistive films, it is easily affected by the contact state, particularly the touch load, and a very strong load is applied. In some cases, such as when it was applied, the determination was wrong.

  The present invention has been made to solve the above-described problems, and a touch panel device capable of stably determining a multi-point touch by considering the influence of the distance between the touch points and the touch load. It aims to be realized.

The touch panel device according to the present invention includes a touch point voltage measuring unit that measures a voltage value between a touch point at which a resistive film is vertically contacted by touch input of a touch panel and an electrode terminal to obtain a touch point voltage, and a touch point voltage. A change amount extraction unit for extracting the amount of change, an inter-terminal resistance measurement unit that measures the resistance value between the electrode terminals of the resistance film and sets the inter-terminal resistance value, and measures the time after the touch input is made, Switching the judgment conditions before and after a predetermined time has passed, and by comparing the change amount extracted by the change amount extraction unit and the inter-terminal resistance value measured by the inter-terminal resistance measurement unit with the judgment condition , multiple points are displayed on the touch panel. And a multi-point touch determination unit that determines whether or not is touched.

  According to this invention, the touch point voltage change amount and the inter-terminal resistance value are used to determine the multi-point touch, so that the influence of the distance between the touch points and the touch load can be taken into consideration. Accordingly, it is possible to realize a touch panel device that determines a multi-point touch stably.

It is a block diagram which shows the structure of the touchscreen apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the circuit structure of the touchscreen apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the touchscreen apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the detailed operation | movement of the touch point voltage measurement part of the touch-panel apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which represented typically the equivalent circuit of the touchscreen TP at the time of touch input in the touchscreen device which concerns on Embodiment 1 of this invention. It is a flowchart which shows detailed operation | movement of the resistance measuring part between terminals of the touchscreen apparatus which concerns on Embodiment 1 of this invention. In the touch panel device according to Embodiment 1 of the present invention, it is an explanatory diagram showing an equivalent circuit configuration between opposing terminals X1 and X2 when one point on the touch panel TP is touched. In the touch panel device according to Embodiment 1 of the present invention, it is an explanatory diagram showing an equivalent circuit configuration between opposing terminals X1 and X2 when two points on the touch panel TP are touched. FIG. 4 is an explanatory diagram showing an equivalent circuit configuration between orthogonal terminals X1 and Y2 when one point on the touch panel TP is touched in the touch panel device according to Embodiment 1 of the present invention. In the touch panel device according to Embodiment 1 of the present invention, it is an explanatory diagram showing an equivalent circuit configuration between orthogonal terminals X1 and Y2 when two points on the touch panel TP are touched. It is a block diagram which shows the structure of the touchscreen apparatus which concerns on Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the touchscreen apparatus which concerns on Embodiment 2 of this invention. It is a flowchart which shows the detailed operation | movement of the multi-point touch determination part of the touchscreen apparatus which concerns on Embodiment 3 of this invention. It is a flowchart which shows the detailed operation | movement of the multi-point touch determination part of the touchscreen apparatus which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
1 is a block diagram showing a configuration of a touch panel device according to Embodiment 1 of the present invention. In FIG. 1, the touch panel device includes a touch panel TP in which two layers of resistive films provided with electrode terminals are stacked, and a voltage value between a touch point where the resistive film contacts up and down by touch input to the touch panel TP and the electrode terminals. Touch point voltage measurement unit 1 that measures the touch point voltage to measure the touch point voltage, Touch point coordinate calculation unit 2 that calculates the position coordinates of the touch point from the touch point voltage, and extracts the amount of change in the touch point voltage using past measurement values A change amount extraction unit 3 that performs the measurement, a resistance measurement unit 4 that measures a resistance value between the electrode terminals of the resistance film, and a multi-point touch determination unit 5 that determines whether or not a plurality of points are touched on the touch panel TP.

  FIG. 2 is an explanatory diagram showing a circuit configuration of the touch panel device of FIG. As shown in FIG. 2, the touch panel TP includes two analog resistance films TP1 and TP2. The resistance film TP1 (hereinafter, appropriately referred to as a resistance film TP1 in the x direction) is provided with a pair of terminals (electrode terminals) X1 and X2 each extending in the x direction at a pair of both ends parallel to the x direction. It has been. The other resistance film TP2 (hereinafter referred to as a resistance film TP2 in the y direction as appropriate) includes a pair of electrodes extending in the y direction at a pair of both ends parallel to the y direction (a direction orthogonal to the x direction). Terminals (electrode terminals) Y1, Y2 are provided. The touch panel TP includes two layers of resistance films TP1 and TP2 so that the terminals X1 and X2 and the terminals Y1 and Y2 are orthogonal to each other.

  The microcomputer M1 includes a CPU, a memory, and an input / output port (not shown), and has functions such as detecting a touch position on the touch panel TP and determining a touch state. The touch point voltage measuring unit 1, touch This corresponds to the point coordinate calculation unit 2, change amount extraction unit 3, inter-terminal resistance measurement unit 4, and multi-point touch determination unit 5.

  Further, the output ports P0 to P7 of the microcomputer M1 are respectively connected to gate terminals of transistors such as MOSFETs constituting the switches SW2, SW3, SW4, SW1, SW6, SW5, SW8, SW7, and the output ports P0 to P0. The switches SW1 to SW8 are opened and closed depending on the output setting to P7.

  The switch SW2 has a source terminal connected to the power supply VCC for applying a predetermined DC voltage and a source terminal of the switch SW3, and a drain terminal connected to one end of the resistor Ra. The switch SW3 has a drain terminal connected to the other end of the resistor Ra connected to the drain terminal of the switch SW2, the input port ADX1, and the terminal X1 of the resistance film TP1. The switch SW4 has a source terminal connected to the power supply VCC and the source terminal of the switch SW6, and a drain terminal connected to the drain terminal of the switch SW1, the input port ADY1, and the terminal Y1 of the resistance film TP2. The switch SW1 has a source terminal grounded to the ground GND.

  The switch SW6 has a source terminal connected to the power supply VCC and a drain terminal connected to one end of the resistor Rb. The switch SW5 has a drain terminal connected to the other end of the resistor Rb connected to the drain terminal of the switch SW6, the input port ADX2 and the terminal X2 of the resistance film TP1, and a source terminal grounded to the ground GND. The switch SW8 has a drain terminal connected to one end of the resistor Rc, the input port ADY2 and the terminal Y2 of the resistance film TP2, and a source terminal grounded to the ground GND. The switch SW7 has a drain terminal connected to one end of the resistor Rc, and a source terminal grounded to the ground GND.

  The input ports ADX1, ADY1, ADX2, and ADY2 of the microcomputer M1 are connected to the terminals X1, Y1, X2, and Y2, respectively, and are generated at the terminals X1, Y1, X2, and Y2 in response to the touch on the touch panel TP. An analog voltage signal indicating a change in resistance value is input to an A / D converter (not shown) in the microcontroller M1. The A / D converter converts analog voltage signals from the terminals X1, Y1, X2, and Y2 into digital data, and outputs the digital data to the touch point voltage measurement unit 1 and the inter-terminal resistance measurement unit 4.

  Touch panel control describing processing contents of the touch point voltage measurement unit 1, the touch point coordinate calculation unit 2, the change amount extraction unit 3, the inter-terminal resistance measurement unit 4, and the multi-point touch determination unit 5 constituting the touch panel device. The program is stored in the memory, and the CPU in the microcomputer M1 reads the program from the memory and executes it, so that it is realized as a specific means in which the hardware and software of the switches SW1 to SW8 and the microcontroller M1 cooperate. can do.

Next, the operation of the touch panel device will be described. FIG. 3 is a flowchart showing the operation of the touch panel device. First, the touch point voltage measuring unit 1 measures the voltage at the touch point on the touch panel TP (step ST10).
FIG. 4 is a flowchart showing a detailed flow of the touch point voltage measurement process (step ST10). First, in order to measure the voltage level in the x direction, the touch point voltage measuring unit 1 controls the output setting to the output ports P0 to P7 in FIG. 2, and opens only the switches SW3 and SW5 (ON. With the source). The drain is turned on), and all other switches are closed (off), so that the DC voltage of the power supply VCC is applied between the terminals X1 and X2 of the resistance film TP1 in the x direction (step ST11).

  FIG. 5A schematically shows an equivalent circuit of the touch panel TP when touch input is performed with a voltage applied between the terminals X1 and X2, and the touch panel TP is shown in the direction of the arrow in FIG. The case where it was pressed is illustrated. When only one point is touched as shown in FIG. 5A with only the switches SW3 and SW5 open, the x-direction resistance film TP1 is placed between the power supply VCC and the ground GND. A circuit is formed in which the resistors (resistance values R1, R3) from the touched position (touch point) to both terminals X1, X2 are connected in series. At this time, the resistance film TP2 in the y direction is connected to the touch point via the contact resistance (resistance value R2). However, no current flows through the contact resistance, and the resistance film TP2 in the y direction is equal to the touch point. Become potential. In this state, the touch point voltage measurement unit 1 measures the voltage level of the terminal Y2 (or the terminal Y1) via the input port ADY2, and acquires the voltage level of the touch point in the x direction (step ST12).

  Subsequently, in order to acquire the voltage level in the y direction, the touch point voltage measurement unit 1 controls the output setting to the output ports P0 to P7, opens only the switches SW4 and SW8, and all the others. Is closed (off), thereby applying the DC voltage of the power supply VCC between the terminals Y1 and Y2 of the resistance film TP2 in the y direction (step ST13).

  FIG. 5B schematically shows an equivalent circuit of the touch panel TP when touch input is performed with a voltage applied between the terminals Y1 and Y2, and the touch panel TP is shown in the arrow direction in FIG. The case where it was pressed is illustrated. When only one of the above points is touched as shown in FIG. 5B with only the switches SW4 and SW8 open, the y-direction resistance film TP2 is placed between the power supply VCC and the ground GND. A circuit is formed in which the resistors (resistance values R4 and R5) from the touched position (touch point) to both terminals Y1 and Y2 are connected in series. At this time, the resistance film TP1 in the x direction is connected to the touch point via the contact resistance (resistance value R2). However, no current flows through the contact resistance, and the resistance film TP1 in the x direction is equal to the touch point. Become potential. In this state, the touch point voltage measurement unit 1 measures the voltage level of the terminal X1 (or may be the terminal X2) via the input port ADX1, and acquires the voltage level of the touch point in the y direction (step ST14).

  When the touch point voltage measuring unit 1 acquires the voltage levels in the x and y directions of the touch point as touch point voltages (step ST10), the touch point coordinate calculating unit 2 calculates the touch point coordinates (step ST20). ). The voltage level in the x direction and y direction at the touch point is a value obtained by dividing the voltage applied from the power supply VCC by the resistance value R1 and the resistance value R3, and the resistance value R4 and the resistance value R5. The touch point coordinate calculation unit 2 knows the x coordinate according to the potential gradient in the x direction on the resistive film TP1 and the y coordinate according to the potential gradient in the y direction on the resistive film TP2, and thus, as described above. The xy coordinates indicating the touch point are calculated using the voltage levels of the touch point in the x direction and y direction. In the state where two points are touched, a touch point voltage corresponding to the middle point between the two points is obtained, and therefore a correct touch point cannot be calculated.

The change amount extraction unit 3 extracts the change amounts from the voltage levels in the x and y directions obtained in step ST10 and the voltage levels in the x and y directions that have been measured and stored in the past (step). ST30). The change amount extraction unit 3 obtains the change amount Dx in the x direction and the change amount Dy in the y direction using, for example, the following equation (1). At the moment of changing from the one-point touch state to the two-point touch state, the voltage value corresponding to the first one-point touch position changes sharply from the voltage value corresponding to the middle point of the two points. It is possible to determine a point touch.
Dx = ABS (Vx−VPx) (1)
Dy = ABS (Vy-VPy)
However, Vx and Vy are voltage levels in the x and y directions obtained in step ST10, VPx and VPy are voltage levels in the x and y directions obtained in the previous cycle, and ABS is an operator that takes an absolute value.

On the other hand, the inter-terminal resistance measurement unit 4 controls the output setting of the output ports P0 to P7 shown in FIG. 2, measures the voltage between the terminals, and obtains the inter-terminal resistance (step ST40). Hereinafter, as an operation example of the inter-terminal resistance measurement unit 4 in step ST40, the counter-terminal resistance measurement process will be described. In the measurement of the resistance between the opposing terminals, the resistance value between the opposing terminals X1 and X2 of the resistance film TP1 in the x direction and the resistance value between the opposing terminals Y1 and Y2 of the resistance film TP2 in the y direction are measured.
FIG. 6 is a flowchart showing a detailed flow of the resistance measurement process between opposing terminals (step ST40). First, the inter-terminal resistance measurement unit 4 controls the output setting to the output ports P0 to P7, opens only the switches SW2 and SW5, and closes (off) all other switches. A DC voltage of the power supply VCC is applied between the terminals X1 and X2 of the resistance film TP1 in the x direction via the resistor Ra (step ST41). In this state, the inter-terminal resistance measurement unit 4 measures the voltage level of the terminal X1 via the input port ADX1 (step ST42). At this time, the measured voltage level of the terminal X1 is a value obtained by dividing the resistance value between the terminals X1 and X2 of the resistance film TP1 in the x direction and the known reference resistance value r of the resistor Ra. The resistance value between the opposing terminals X1 and X2 of the resistance film TP1 in the direction can be obtained (step ST43).

  Subsequently, the inter-terminal resistance measurement unit 4 controls the output setting to the output ports P0 to P7 so that only the switches SW4 and SW7 are opened (on) and all other switches are closed (off). The DC voltage of the power supply VCC is applied between the terminals Y1 and Y2 of the resistance film TP2 in the y direction via the resistor Rc (step ST44). In this state, the inter-terminal resistance measurement unit 4 measures the voltage level of the terminal Y2 through the input port ADY2 (step ST45). At this time, the measured voltage level of the terminal Y2 is a value obtained by dividing the resistance value between the terminals Y1 and Y2 of the resistance film TP2 in the y direction and the known reference resistance value r of the resistor Rc. The resistance value between the opposing terminals Y1 and Y2 of the resistance film TP2 in the direction can be obtained (step ST46).

  Here, the principle of the phenomenon in which the resistance value between the opposing terminals is lower than when one point is touched when touching two points on the touch panel TP is as follows: when one point is touched and when two points are touched Separately described. FIG. 7A schematically shows an equivalent circuit between the opposing terminals X1 and X2 when one point on the touch panel TP is touched, and FIG. 7B is an equivalent circuit thereof. When one point is pressed in the direction indicated by the arrow in FIG. 7A in a state where the voltage VCC is applied between the opposing terminals X1 and X2 via the resistor Ra, the opposing terminals X1 and X2 are connected to each other as shown in FIG. As shown in b), a circuit is formed in which the resistors (resistance values R1, R3) from the touch point on the resistance film TP1 in the x direction to both terminals X1, X2 are connected in series.

  On the other hand, FIG. 8A schematically shows an equivalent circuit between the opposing terminals X1 and X2 when two points on the touch panel TP are touched, and FIG. 8B is an equivalent circuit thereof. When two points are pressed in the direction indicated by the arrow in FIG. 8A in a state where the voltage VCC is applied between the opposing terminals X1 and X2 via the resistor Ra, the x direction as shown in FIG. A resistance value (resistance value) between two points on the resistance film TP1 in the x direction between the resistances (resistance values R1, R3) from the position of the two touch points to the terminals X1, X2 on the resistance film TP1. R4), a circuit in which a parallel circuit is connected by a resistance value (resistance value R4) between two points on the resistance film TP2 in the y direction and a contact resistance (resistance value R2) is formed. Therefore, a phenomenon occurs in which the resistance value between the opposing terminals X1 and X2 is reduced by the amount of parallel circuit formation as compared with the one-point touch shown in FIG. Similarly, a phenomenon occurs in which the resistance value decreases between the opposing terminals Y1 and Y2 on both ends of the resistance film TP2 in the y direction. By detecting this resistance value decrease, it is possible to determine multi-point touch. However, the resistance value between the opposing terminals X1 and X2 is the one-point touch shown in FIG. 7 because the resistance (resistance value R4) between the two points decreases as the distance between the two touched points on the touch panel TP decreases. Compared to the time, the degree of decrease in the resistance value becomes small, and determination of multi-point touch becomes difficult. The same applies to the y direction.

  The above is an example of the inter-terminal resistance measurement processing operation of the inter-terminal resistance measurement unit 4 in step ST40. However, in this step ST40, the multipoint touch determination unit 5 may measure the resistance value between the orthogonal terminals. Hereinafter, an operation example of resistance measurement between orthogonal terminals will be described. The inter-terminal resistance measurement unit 4 sets voltages to be applied to the output ports P0 to P7 shown in FIG. 2, opens and closes the switches SW1 to SW8, and reads the voltages input from the input ports ADX1, ADY1, ADX2, and ADY2. Measure the resistance between the 4 terminals. For example, when measuring the resistance value between the orthogonal terminals X1 and Y2, the inter-terminal resistance measuring unit 4 opens only the switches SW2 and SW8 and closes all the other switches (off). The output value applied to the ports P0 to P7 is controlled.

  FIG. 9A schematically shows an equivalent circuit between the orthogonal terminals X1 and Y2 when one point on the touch panel TP is touched, and FIG. 9B is an equivalent circuit thereof. If only one point is touched in the direction of the arrow in FIG. 9A with only the switches SW2 and SW8 being opened, as shown in FIG. 9B, between the power supply VCC and the ground GND. This occurs when the resistance Ra has a known resistance value (reference resistance value r), the resistance on the resistance film TP1 in the x direction (resistance value R1), and the resistance film TP1 in the x direction and the resistance film TP2 in the y direction contact each other. A circuit is formed in which the contact resistance (resistance value R2) and the resistance (resistance value R3) on the resistance film TP2 in the y direction are connected in series.

  In this state, the inter-terminal resistance measurement unit 4 converts an analog voltage signal indicating the voltage value of the input port ADX1 connected to the terminal X1 into digital data by an A / D converter (not shown). Since the terminal Y2 is connected to the ground GND, the voltage value of the input port ADX1 becomes the voltage value between the orthogonal terminals X1 and Y2. The inter-terminal resistance measurement unit 4 uses a known voltage value supplied from the power supply VCC, a voltage value between the orthogonal terminals X1 and Y2, and a known reference resistance value r of the resistor Ra, and uses a resistance between the orthogonal terminals X1 and Y2. Calculate the value.

  Similarly, the inter-terminal resistance measurement unit 4 controls the output setting to the output ports P0 to P7 so that only the switches SW1 and SW2 are open (on) and all other switches are closed (off). The voltage value of the input port ADX1 is measured, and the resistance value between the orthogonal terminals X1 and Y1 is calculated. Subsequently, the inter-terminal resistance measurement unit 4 controls the output setting to the output ports P0 to P7 so that only the switches SW1 and SW6 are opened (on) and all other switches are closed (off). The voltage of the port ADX2 is measured, and the resistance value between the orthogonal terminals X2 and Y1 is calculated. Further, the inter-terminal resistance measurement unit 4 controls the output setting to the output ports P0 to P7 so that only the switches SW6 and SW8 are open (on) and all the other switches are closed (off). The voltage of ADX2 is measured, and the resistance value between the orthogonal terminals X2 and Y2 is calculated in the same manner as described above. In this way, four resistance values between the orthogonal terminals (between the terminals X1 and Y2, between the terminals X1 and Y1, between the terminals X2 and Y1, and between the terminals X2 and Y2) are obtained.

  FIG. 10A schematically shows an equivalent circuit between the orthogonal terminals X1 and Y2 when two points on the touch panel TP are touched, and FIG. 10B is an equivalent circuit thereof. Here, using FIG. 9 and FIG. 10, the principle of the phenomenon that the resistance value between the orthogonal terminals is lower when the two points on the touch panel TP are touched than when the one point is touched is as follows. A description will be given separately for the case where two points are touched. As shown in FIG. 9, when one point is pressed with the voltage VCC applied between the orthogonal terminals X1 and Y2, a resistance (resistance value R1) on the resistance film TP1 in the x direction is interposed between the orthogonal terminals X1 and Y2. ), A resistance in which the contact resistance (resistance value R2) and the resistance on the resistance film TP2 in the y direction (resistance value R3) are connected in series.

  On the other hand, when the voltage VCC is applied between the orthogonal terminals X1 and Y2 and two points are pressed in the direction indicated by the arrow in FIG. 10A, the orthogonal terminals X1 and Y2 are connected as shown in FIG. As shown, the resistance (resistance value R2) on the resistance film TP1 in the x direction (resistance value R2), the resistance on the resistance film TP2 in the y direction (resistance value R3), and the two pressed points A circuit in which the resistors (resistance value R4) are connected in parallel is formed. At this time, as the resistance value R4 of the resistance between the two pressed points decreases, that is, as the distance between the two points decreases, the resistance value between the orthogonal terminals X1 and Y2 becomes the minimum value (R1 + (R2 + R3 ) / 2) (when R4 → 0) On the other hand, as the resistance value R4 increases, that is, as the distance between the two points increases, the resistance value between the orthogonal terminals X1 and Y2 approaches the maximum value (R1 + R2 + R3) (when R4 → ∞). .

As described above, the resistance value between the orthogonal terminals X1 and Y2 monotonously increases with respect to the resistance value R4 as shown by the inequality of the following equation (2). Therefore, the resistance value between the orthogonal terminals X1 and Y2 when the two points are touched is lower than the resistance value (R1 + R2 + R3) between the orthogonal terminals X1 and Y2 when the one point is touched. The relationship of the following formula (2) is similarly established between the other three orthogonal terminals (between terminals X1 and Y1, between terminals X2 and Y1, and between terminals X2 and Y2).
(R1 + (R2 + R3) / 2)
<Resistance value between orthogonal terminals X1 and Y2 <(R1 + R2 + R3) (2)

  Unlike the above-described resistance value between the opposing terminals, the resistance value between the orthogonal terminals obtained here does not approach the value at the time of one-point touch even when the distance between the two points at the time of two-point touch is very small. However, since the contact resistance (resistance value R2) is included, the value varies depending on the touch load. For this reason, it is difficult to determine when the touch load is extremely large or extremely small.

  The multi-point touch determination unit 5 determines whether the multi-point touch is 1 based on the change amount of the touch point voltage extracted by the change amount extraction unit 3 in step ST30 and the inter-terminal resistance value measured by the inter-terminal resistance measurement unit 4 in step ST40. It is determined whether it is a point touch (step ST50). If the inter-terminal resistance measurement unit 4 measures both the resistance value between the opposing terminals and the resistance value between the orthogonal terminals, the multi-point touch determination unit 5 is, for example, a multi-point touch if any one of the following determination conditions is satisfied, and if all are not satisfied It is determined as a one-point touch.

(1) Either the touch point voltage change amount Dx or Dy obtained in step ST30 exceeds the threshold value. (2) The counter terminal resistance value obtained in step ST40 is smaller than the threshold value. (3) Obtained in step ST40. The resistance between orthogonal terminals is smaller than the threshold value

  As described above, it is difficult to determine that the distance between two points is small (when two points are touched) in the resistance value (2) between the opposing terminals, while in the condition (3) between the orthogonal terminals, the touch is difficult. It is difficult to judge when the load is very small or large. On the other hand, the amount of change in the touch point voltage is not affected by the touch load, and by capturing the steepness of the change, it is also affected by the distance between the two points compared to the resistance value between the orthogonal terminals. Hateful. Therefore, by using the condition (1) in combination, the multipoint touch determination unit 5 can determine multipoint touch stably. However, since the change amount of the touch point voltage captures the change from the one-point touch state to the two-point touch state, it cannot be determined from the beginning when the two-point touch state is set. It is necessary to catch by conditions.

  As described above, according to the first embodiment, the resistance films TP1 and TP2 provided on the end sides where the pair of terminals (X1, X2, Y1, and Y2) are opposed to each other are vertically arranged so that the terminals are orthogonal to each other. When the resistance film surface is pressed down by touch input, the upper and lower resistance films TP1 and TP2 are in contact with each other, and the touch point where the resistance films TP1 and TP2 are vertically contacted by touch input and the terminals Touch point voltage measurement unit 1 that measures the voltage value of the touch point to obtain the touch point voltage, touch point coordinate calculation unit 2 that calculates the position coordinates of the touch point based on the touch point voltage, and the amount of change in the touch point voltage is extracted And measuring the resistance value between the change amount extraction unit 3 and the terminals orthogonal to the resistance films TP1 and TP2 (between the terminals X1 and Y2, between the terminals X1 and Y1, between the terminals X2 and Y1, and between the terminals X2 and Y2). Oppose The inter-terminal resistance measurement unit 4 that measures the resistance value between the terminals (between the terminals X1 and X2 and between the terminals Y1 and Y2) to obtain the inter-terminal resistance value, and the change amount and the inter-terminal resistance value are set as predetermined determination conditions. In light of this, a multi-point touch determination unit 5 that determines whether or not a plurality of points are touched on the touch panel TP is provided. With this configuration, it is possible to stably detect a multi-point touch without being affected by the distance between touch points and the touch load.

  In the first embodiment, both the resistance value between the opposing terminals and the resistance value between the orthogonal terminals are used as the inter-terminal resistance value, but only one of them may be used. Moreover, although the example which compares a measured value and a threshold value was demonstrated as a determination condition of the multipoint touch by the resistance value between terminals, this may be another determination method. For example, the standard value of each resistance value may be stored and determined by the amount of difference from the standard value, or an operation such as obtaining the sum or difference is performed on the measured value, and the calculation is performed. A determination may be made based on the result. In addition, the change amount extraction unit 3 extracts the change amount from the measured value in the past in one cycle with respect to the touch point voltage in the x direction and the y direction. In addition, the amount of change obtained by integrating both the Euclidean distance and the like may be extracted instead of the amount of change independent in the x direction and the y direction.

Embodiment 2. FIG.
FIG. 11 is a block diagram showing the configuration of the touch panel device according to Embodiment 2 of the present invention. The same or corresponding parts as those in FIG.
In the present embodiment, the change amount extraction unit 3 extracts the change amount of the touch point voltage and also extracts the change amount of the inter-terminal resistance, and the multi-point touch determination unit 5 measures the inter-terminal resistance measurement unit 4. When the value of the inter-terminal resistance satisfies a predetermined condition, or when both the change amount of the touch point voltage extracted by the change amount extraction unit 3 and the change amount of the inter-terminal resistance satisfy the predetermined condition, judge.

  Next, the operation of the touch panel device according to Embodiment 2 will be described. FIG. 12 is a flowchart showing the operation of the touch panel device. Steps ST10 to ST40 in FIG. 12 are the same as steps ST10 to ST40 in FIG. After performing the operations of steps ST10 to ST40, the change amount extraction unit 3 extracts the change amount of the inter-terminal resistance (step ST60). For example, the amount of change is calculated according to the following equation (3) for the resistance value between the opposing terminals, and according to the following equation (4) for the resistance value between the orthogonal terminals.

Change amount of resistance value between terminals X1 and X2 = Rx−RPx (3)
Change amount of resistance value between terminals Y1 and Y2 = Ry−RPy
However, Rx and Ry are the resistance values between the terminals X1, X2 and between the terminals Y1, Y2 obtained in step ST40, and RPx and RPy are the values between the terminals X1, X2 and between the terminals Y1, Y2 obtained in the past in one cycle. This is the resistance between terminals.

Change amount of resistance value between terminals X1 and Y2 = Rx1y2-RPx1y2 (4)
Change amount of resistance value between terminals X1 and Y1 = Rx1y1-RPx1y1
Change amount of resistance value between terminals X2 and Y1 = Rx2y1-RPx2y1
Change amount of resistance value between terminals X2 and Y2 = Rx2y2-RPx2y2
However, Rx1y2, Rx1y1, Rx2y1 and Rx2y2 are the resistance values between the terminals X1 and Y2, the terminals X1 and Y1, the terminals X2 and Y1, and the terminals X2 and Y2 obtained in step ST40. Further, RPx1y2, RPx1y1, RPx2y1 and RPx2y2 are inter-terminal resistance values obtained between terminals X1 and Y2, between terminals X1 and Y1, between terminals X2 and Y1, and between terminals X2 and Y2 obtained in the past in one cycle.

  Alternatively, when the multi-point touch determination unit 5 uses the calculated value instead of the inter-terminal resistance value itself in step ST70 below, the change amount extraction unit 3 extracts the change amount of the calculated value in step ST60. May be. For example, it is conceivable to take the sum of two values for the resistance value between the opposing terminals and to sum the four values for the resistance value between the orthogonal terminals.

  Subsequently, the multi-point touch determination unit 5 determines whether it is a multi-point touch or a one-point touch from the change amount extracted by the change amount extraction unit 3 and the inter-terminal resistance value measured by the inter-terminal resistance measurement unit 4 ( Step ST70). For example, if any one of the following determination conditions is satisfied, a multi-point touch is determined, and if all are not satisfied, a one-point touch is determined.

(1) Either the touch point voltage change amount Dx or Dy obtained in step ST30 exceeds the threshold value, and the change amount of the orthogonal terminal resistance value obtained in step ST60 exceeds the threshold value. (2) In step ST40. The obtained resistance value between the opposing terminals is smaller than the threshold value (3) The resistance value between the orthogonal terminals obtained in step ST40 is smaller than the threshold value.

  Since the touch point voltage changes according to the position of the touch point, for example, when the finger is moved very rapidly while the touch panel TP is pressed, the touch point voltage also changes sharply. For this reason, when it is determined only by the change amount of the touch point voltage, there is a possibility that a high-speed finger movement is erroneously determined as a multi-point touch. By doing so, this erroneous determination can be avoided.

  As described above, according to the second embodiment, the change amount extraction unit 3 extracts the change amount of the touch point voltage and extracts the change amount of the inter-terminal resistance value measured by the inter-terminal resistance measurement unit 4. When the multi-point touch determination unit 5 satisfies the predetermined determination condition of the inter-terminal resistance value measured by the inter-terminal resistance measurement unit 4, or between the change amount of the touch point voltage extracted by the change amount extraction unit 3 and the terminal When both of the change amounts of the resistance value satisfy a predetermined determination condition, it is determined that a plurality of points are touched. Therefore, even when a finger is moved at high speed on the touch panel TP, it is possible to correctly determine a multi-point touch.

  In the second embodiment, the AND condition of the change amount of the touch point voltage and the change amount of the resistance value between the orthogonal terminals is used as the determination condition in step ST70, but instead of the change amount of the resistance value between the orthogonal terminals. Alternatively, the change amount of the resistance value between the opposing terminals may be used, or three AND conditions of the change amount of the touch point voltage, the change amount of the resistance value between the orthogonal terminals, and the change amount of the resistance value between the opposing terminals may be used. Further, the change amount extraction unit 3 extracts the change amount from the value obtained in the past for one cycle with respect to the inter-terminal resistance value, but this indicates the change amount from the acquired value in the past for a plurality of cycles or a predetermined time. It may be extracted.

Embodiment 3 FIG.
The touch panel device according to this embodiment has the same configuration as that of the touch panel device according to the first embodiment shown in FIG. 1, and will be described below with reference to FIG. 1. The operation of the touch panel device according to this embodiment is the same from step ST10 to step ST40 shown in FIG. 3, and only the multipoint touch determination process of the multipoint touch determination unit 5 in step ST50 is different. The multi-point touch determination unit 5 stores past determination results, and switches the multi-point touch determination condition based on the past determination results, and determines whether multi-point touch or single-point touch (step ST50). . FIG. 13 is a flowchart showing a detailed flow of the multipoint touch determination process (step ST50) of the multipoint touch determination unit 5 in the third embodiment.

  The multi-point touch determination unit 5 stores a determination result in the past of one cycle, and first checks whether or not the state in the past of the one cycle is a non-touch state (step ST51). In the non-touch state (step ST51 “Yes”), the multipoint touch determination unit 5 performs multipoint touch determination under a predetermined determination condition A (step ST52). An example of the determination condition A is shown below. In the case where the state past one cycle is a non-touch state, there is a restriction that there is no measurement value past one cycle and the change amount of the touch point voltage cannot be used. Separated from C, it is made independent as determination condition A.

(Condition A) When one of the following (A1) and (A2) is established, a multipoint touch is determined.
(A1) Resistance value between opposed terminals is smaller than threshold (A2) Resistance value between orthogonal terminals is smaller than threshold

  If the state past one cycle is the touch state (step ST51 “No”), then the multipoint touch determination unit 5 checks whether the determination result past one cycle is a multipoint touch (step ST53). ). The multi-point touch determination unit 5 performs multi-point touch determination under a predetermined determination condition B (step ST54) if it is not a multi-point touch (step ST53 “No”), and if it is a multi-point touch (step ST53 “Yes”). ) A multi-point touch determination is performed under a predetermined determination condition C (step ST55). Examples of determination conditions B and C are shown below.

(Condition B) If any one of the following (B1) to (B3) is established, a multi-point touch is determined.
(B1) Either the touch point voltage change amount Dx or Dy exceeds the threshold value (B2) The resistance value between the opposing terminals is smaller than the threshold value (B3) The resistance value between the orthogonal terminals is smaller than the threshold value

(Condition C) If the resistance value between the opposing terminals is equal to or greater than the threshold value, it is determined as one-point touch, and if it is less than the threshold value, it is determined as multi-point touch. However, the threshold value of this condition is a value greater than a certain value than the threshold value of the resistance value between the opposing terminals used in the above (A1) and (B2).

  The determination condition B is a condition for detecting a change from the one-point touch state to the multi-point touch state, and the determination condition C is a condition for detecting a change from the multi-point touch state to the one-point touch state. For example, when it is desired to prevent the malfunction of the device as much as possible, it is desirable to determine that it is one point only when it can be reliably regarded as a one-point touch. In the present embodiment, the determination condition B is set as an OR condition based on a plurality of measurement values, so that it is easy to determine a multi-point touch, while the determination condition C can be mistaken for a single point touch by using a strict threshold single condition. Reduced. As described above, by switching the determination condition according to the past determination result, it is possible to make an adjustment that makes it easier to determine either the one-point touch state or the multiple-point touch state.

  As described above, according to the third embodiment, the multi-point touch determination unit 5 stores the past determination results and switches the determination conditions in accordance with the past determination results. A plurality of points are touched by checking the amount of change extracted by the extraction unit 3 and the inter-terminal resistance value (the resistance value between the opposing terminals and the resistance value between the orthogonal terminals) measured by the inter-terminal resistance measurement unit 4 with the determination condition. Judgment was made. Therefore, it is possible to reduce errors that determine a multipoint touch state as one-point touch, and it is possible to suppress malfunctions of the touch panel device due to erroneous touch point determination.

  In the third embodiment, the determination condition A is an OR condition of two types of values, the determination condition B is an OR condition of three types of values, and the determination condition C is an independent condition of the resistance value between opposing terminals. May be different conditions or combination conditions.

Embodiment 4 FIG.
The multi-point touch determination unit 5 according to the third embodiment is configured to switch the determination conditions for the multi-point touch based on the past determination results. However, the multi-point touch determination unit 5 according to the present embodiment is arranged on the touch panel TP. The counter has a counter for measuring the time (number of cycles) after the touch state is generated, and the judgment condition for the multipoint touch is switched before and after a predetermined time has elapsed.

  The touch panel device according to this embodiment has the same configuration as that shown in FIG. 1 and will be described below with reference to FIG. The operation of the touch panel device according to this embodiment is the same from step ST10 to step ST40 shown in FIG. 3, and only the multipoint touch determination process of the multipoint touch determination unit 5 in step ST50 is different. After the operations of steps ST10 to ST40, the multipoint touch determination unit 5 counts the time after the touch state occurs, switches the determination condition according to the time, and determines whether the multipoint touch or the single point touch. Determination is made (step ST50). FIG. 14 is a flowchart showing a detailed flow of the multi-point touch process (step ST50 shown in FIG. 3) of multi-point touch determination unit 5 in the fourth embodiment.

  The multi-point touch determination unit 5 stores a determination result in the past of one cycle, and first checks whether or not the state in the past of the one cycle is a non-touch state (step ST51a). In the non-touch state (step ST51a “Yes”), the multipoint touch determination unit 5 performs multipoint touch determination under a predetermined determination condition A (step ST52a), and then resets the counter to 1 (step ST53a). This counter counts the number of cycles since the touch state is entered, and is used as a substitute for a clock that measures the time after the touch state is entered. The determination condition A is the same as the determination condition A illustrated in the third embodiment.

  If the state past one cycle is the touch state (step ST51a “No”), then the multipoint touch determination unit 5 checks whether the value of the counter exceeds the threshold value (step ST54a). The multi-point touch determination unit 5 performs multi-point touch determination under a predetermined determination condition B (step ST55a) if the counter value does not exceed the threshold (step ST54a “No”), and if it exceeds (step ST54a “Yes”). ") Multi-point touch determination is performed under a predetermined determination condition C (step ST56a). Examples of determination conditions B and C are shown below. After performing the process of step ST55a or step ST56a, the multipoint touch determination unit 5 adds 1 to the counter in preparation for the next cycle (step ST57a), and ends the multipoint touch determination process.

(Condition B) If any one of the following (B1) to (B3) is established, a multi-point touch is determined.
(B1) Either the touch point voltage change amount Dx or Dy exceeds the threshold value (B2) The resistance value between the opposing terminals is smaller than the threshold value (B3) The resistance value between the orthogonal terminals is smaller than the threshold value

(Condition C) If one of the following (C1) and (C2) is established, a multipoint touch is determined.
(C1) Either the touch point voltage change amount Dx or Dy exceeds the threshold value. (C2) The resistance value between the opposing terminals is smaller than the threshold value.

  As described above, the resistance value between the orthogonal terminals is easily affected by the touch load, and when the touch load is very large, the resistance value may be close to a single point touch or a multipoint touch. However, because humans perform the action of pressing the touch panel, even if it is pressed with force, a large load will not be applied from the first touch, and it should be a relatively small load at the first stage. It is. In the present embodiment, at the initial stage of the touch where the load value is relatively small, the determination is made based on the determination condition B referring to the resistance value between the orthogonal terminals, and the resistance value between the orthogonal terminals is determined from the time when the load value may increase. Therefore, no erroneous determination is made even when a large load is applied.

  As described above, according to the fourth embodiment, the multi-point touch determination unit 5 is configured to measure the time after the touch input is performed, and to switch the determination condition before and after the predetermined time elapses. By comparing the change amount extracted by the change amount extraction unit 3 and the inter-terminal resistance value measured by the inter-terminal resistance measurement unit 4 (the resistance value between the opposing terminals and the resistance value between the orthogonal terminals), a plurality of points are checked. It was determined whether or not was touched. Therefore, it is possible to more accurately determine the multi-point touch state and the one-point touch state.

  In the fourth embodiment, the determination condition A is an OR condition of two types of values, the determination condition B is an OR condition of three types of values, and the determination condition C is an OR condition of two types of values. These may be different conditions or combination conditions.

  In the first to fourth embodiments described above, the case of two-point touch has been described as a specific example of multi-point touch. However, the same processing can be performed for touches of three or more points. In addition, although the amount of change in touch point voltage was used as a determination condition, the touch point coordinates calculated from the touch point voltage are the same type as the touch point voltage, and instead of the amount of change in touch point voltage, the calculated touch point is used. Using the amount of change in coordinates does not depart from the scope of the present application. In addition, the example in which the inter-terminal resistance value is obtained from the voltage level between the terminals and the multipoint touch is determined using this value or the amount of change has been described. Yes, even if a multi-point touch is determined using a voltage level value or a change amount between terminals, it does not deviate from the scope of the present application.

  1 Touch point voltage measurement unit, 2 Touch point coordinate calculation unit, 3 Change amount extraction unit, 4 Terminal resistance measurement unit, 5 Multiple point touch determination unit, ADX1, ADX2, ADY1, ADY2 input port, M1 microcomputer, P0 P7 output port, Ra to Rc resistance, r reference resistance value, R1 to R5 resistance value, SW1 to SW8 switch, TP touch panel, TP1 x direction resistance film, TP2 y direction resistance film, VCC power supply, X1, X2, Y1 , Y2 terminal.

Claims (4)

A pair of electrode terminals are arranged on opposite side edges of the resistance film so that the electrode terminals are perpendicular to each other, and the upper and lower resistance films come into contact with each other when the resistance film surface is pressed by touch input. In a touch panel device equipped with a touch panel,
A touch point voltage measurement unit that measures a voltage value between a touch point at which the resistive film is touched up and down by touch input of the touch panel and the electrode terminal, and sets the touch point voltage;
A change amount extraction unit for extracting a change amount of the touch point voltage;
An inter-terminal resistance measurement unit that measures the resistance value between the electrode terminals of the resistance film and sets the inter-terminal resistance value;
The time after touch input is measured, the judgment condition is switched before and after a predetermined time has passed, and the change amount extracted by the change amount extraction unit and the inter-terminal resistance value measured by the inter-terminal resistance measurement unit And a multi-point touch determination unit that determines whether or not a plurality of points are touched on the touch panel.   2. The touch panel device according to claim 1, wherein the inter-terminal resistance measurement unit measures a resistance value between the electrode terminals of the upper and lower resistive films orthogonal to each other to obtain an inter-terminal resistance value.   3. The touch panel device according to claim 1, wherein the inter-terminal resistance measurement unit measures the resistance value between the opposing electrode terminals of the upper and lower resistance films to obtain the inter-terminal resistance value. 4.   The touch point coordinate calculation part which calculates the position coordinate of a touch point based on the touch point voltage which the touch point voltage measurement part measured is provided, The any one of Claims 1-3 characterized by the above-mentioned. The touch panel device described.

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