JP2022050151A - Touch panel drive device and touch panel device - Google Patents

Abstract

To prevent the accuracy of detection from decreasing in the area of boundary receive signal lines when detecting with a plurality of sensor ICs.SOLUTION: When a plurality of receive signal lines in an adjacent state which are some of all receive signal lines in a touch panel are defined as a first receive signal line group and a plurality of receive signal lines successively disposed in the adjacent state, where only one receive signal line is included in the first receive signal line group, are defined as a second receive signal line group, a touch panel drive device is constituted so as to comprise: a first receive circuit for performing a sensing scan on each receive signal line of the first receive signal line group; a second receive circuit for performing a sensing scan on each receive signal line of the second receive signal line group; and a control unit for exercising control to switch signal paths so that the receive signals received by a boundary receive signal line are supplied to the first and second receive circuits at different timing.SELECTED DRAWING: Figure 12

Description

The present invention relates to a touch panel drive device and a touch panel device, and particularly to a sensing technique.

Various techniques are known for touch panels, and in Patent Document 1 below, two sets (a pair of transmission signal lines and a pair of reception signal lines) are simultaneously sensed to detect the touch operation position. Sensing techniques that improve resolution by doing so are disclosed.

Japanese Unexamined Patent Publication No. 2019-139361

In recent years, there has been a demand for larger touch panels, but it is necessary not to widen the sensor cell pitch in order to maintain sensing accuracy, and for this reason, the number of transmission signal lines and reception signal lines to be scanned increases. Therefore, it is considered to share and sense each area by using a plurality of sensor ICs.

However, in the case of a method of scanning a pair of transmission signal lines and a pair of reception signal lines, if a plurality of sensor ICs scan the reception signal line group in the corresponding area, the boundary between the areas is reached. The signals of a pair of adjacent reception signal lines cannot be taken into one sensor IC, which causes a part where sensing cannot be performed. Since the touch position cannot be detected at that location, the sensing accuracy is reduced.

In view of such a problem, the present invention solves the problem that the touch position cannot be detected at the boundary even when sensing is performed by using a plurality of sensor ICs, and makes it possible to maintain the sensing accuracy.

The touch panel drive device according to the present invention is a touch panel drive device that sequentially scans a touch panel to select a pair of adjacent transmission signal lines and a pair of adjacent reception signal lines. Here, a plurality of received signal lines that are a part of all the received signal lines on the touch panel and are arranged in an adjacent state are set as the first received signal line group, and all the received signal lines on the touch panel are used. A plurality of received signal lines that are a part of the above and are arranged in an adjacent state, and only one received signal line is included in the first received signal line group. Is the second received signal line group. In this case, the touch panel drive device includes a first reception circuit configured to be capable of performing sensing scanning on each reception signal line of the first reception signal line group, and the first reception circuit. Is a separate IC chip, and has a second receiving circuit configured so that sensing scanning can be performed on each received signal line of the second received signal line group, and the first received signal line. The signal path of the signal path so that the reception signal by the boundary reception signal line included in both the group and the second reception signal line group is supplied to the first reception circuit and the second reception circuit at different timings. It is provided with a control unit that performs switching control.
That is, different reception circuits are in charge of sensing the first reception signal line group and the second reception signal line group. At this time, the first and second received signal line groups are configured to include the received signal lines that are the boundaries thereof. That is, for the boundary reception signal line, the first reception circuit can sense and the second reception circuit can also sense.
Further, the touch panel device according to the present invention is composed of the above touch panel drive device and a touch panel.

In the touch panel drive device and the touch panel device described above, a pair of received signal lines are sequentially selected by the multiplexer in the scanning process for each of the first receiving circuit and the second receiving circuit. It is conceivable that the control unit is configured to be connected, and the switching control is performed by setting terminals for the multiplexer.
The received signal lines on the touch panel are connected to the multiplexer, the pair of received signal lines are sequentially selected and connected to the first receiving circuit in the multiplexer, and the other pair of received signal lines are sequentially selected and the second receiving circuit. Connected to. In this case, switching of the connection for one reception signal line as a boundary is performed in the multiplexer.

In the touch panel drive device and the touch panel device described above, a first multiplexer that selectively connects each received signal line of the first received signal line group to the first receiving circuit, and the second received signal line. The control unit includes a second multiplexer that selectively connects each reception signal line of the group to the second reception circuit, and the control unit receives the boundary reception signal line by the first multiplexer. When connected to the circuit, the boundary reception signal line is disconnected from the second reception circuit by the second multiplexer, and the boundary reception signal line is received by the second multiplexer. When connecting to the circuit, it is conceivable to control the boundary reception signal line so as not to be connected to the first reception circuit by the first multiplexer.
When the boundary reception signal line is connected to one receiving circuit, it is not connected to the other receiving circuit, that is, the wiring to the other receiving circuit is open.

In the above-mentioned touch panel drive device and touch panel device, the first receiving circuit selectively selects a terminal to which each reception signal line of the first reception signal line group excluding the boundary reception signal line is connected and a specific terminal. A first multiplexer connected to the above, and a second multiplexer for selectively connecting a terminal to which each reception signal line of the second reception signal line group is connected to the second reception circuit are provided. When connecting the boundary reception signal line to the first receiving circuit, the control unit controls the second multiplexer to connect the boundary signal line to the specific terminal of the first multiplexer. At the same time, it is conceivable to control the first multiplexer to connect the specific terminal to the first receiving circuit.
The boundary reception signal line is connected to one multiplexer, but it can also be connected to the other multiplexer by wiring between the multiplexers.

According to the present invention, even when sensing is performed using a plurality of sensor ICs (IC chips), the boundary reception signal line can be scanned by the first and second reception circuits, and an appropriate touch detection operation can be performed. realizable. As a result, the sensing accuracy can be maintained even in a configuration using a plurality of sensor ICs with a large touch sensor or the like.

It is a block diagram of the touch panel apparatus of embodiment of this invention. It is explanatory drawing of the signal line structure of the touch panel of embodiment. It is explanatory drawing of the sensing operation of embodiment. It is explanatory drawing of the capacity part for measurement of embodiment. It is a flowchart of the sensing operation procedure of embodiment. It is explanatory drawing of the control at the time of sensing of embodiment. It is explanatory drawing of the sensing of the plurality of channels of embodiment. It is explanatory drawing of allocation of a plurality of sensor ICs. It is explanatory drawing of the allocation of the plurality of sensor ICs of embodiment. It is explanatory drawing of the decrease in sensing accuracy at a boundary. It is explanatory drawing of correspondence to the received signal line of the boundary of the 1st Embodiment. It is explanatory drawing of the sensing by the plurality of sensor ICs of embodiment. It is explanatory drawing of the switching control of the signal path of embodiment. It is explanatory drawing of correspondence to the received signal line of the boundary of the 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in the following order.
<1. Touch panel device configuration>
<2. Sensing operation>
<3. First Embodiment>
<4. Second Embodiment>
<5. Summary and modification>

<1. Touch panel device configuration>
FIG. 1 shows a configuration example of the touch panel device 1 according to the embodiment.
The touch panel device 1 is mounted as a user interface device in various devices. Here, various devices are assumed to be, for example, electronic devices, communication devices, information processing devices, manufacturing equipment, machine tools, vehicles, aircraft, building equipment, and other equipment in a wide variety of fields. The touch panel device 1 is adopted as an operation input device used for user operation input in these various equipment products.
FIG. 1 shows a touch panel device 1 and a product-side MCU (Micro Control Unit) 90, and the product-side MCU 90 indicates a control device in a device to which the touch panel device 1 is mounted. The touch panel device 1 performs an operation of supplying information on the user's touch panel operation to the product side MCU 90.

The touch panel device 1 includes a touch panel 2 and a touch panel drive device 3.
The touch panel drive device 3 has two sensor ICs (Integrated Circuits) 4A and 4B and an MCU 5 in this example.
The touch panel drive device 3 is connected to the touch panel 2 via the touch panel side connection terminal unit 31. The touch panel drive device 3 drives (sensing) the touch panel 2 via this connection.
When mounted on a device as an operation input device, the touch panel drive device 3 is connected to the product side MCU 90 via the product side connection terminal unit 32. Through this connection, the touch panel drive device 3 transmits the sensed operation information to the MCU 90 on the product side.

The sensor IC 4A in the touch panel drive device 3 includes a transmission circuit 41A, a reception circuit 42A, a multiplexer 43A, an interface register circuit 44A, and a power supply circuit 45A.
Similarly, the sensor IC 4B includes a transmission circuit 41B, a reception circuit 42B, a multiplexer 43B, an interface register circuit 44B, and a power supply circuit 45B.

The sensors IC4A and 4B are, for example, IC chips having the same configuration.
When each sensor IC such as sensor ICs 4A and 4B is generically referred to as "sensor IC4". Similarly, when each part in the sensor IC 4 is generically referred to, it is described as "transmission circuit 41", "reception circuit 42", "multiplexer 43", "interface register circuit 44", and "power supply circuit 45".

The transmission circuit 41 of each sensor IC 4 outputs a transmission signal to the terminal on the touch panel 2 selected by the multiplexer 43. Further, the receiving circuit 42 receives a signal from the terminal on the touch panel 2 selected by the multiplexer 43, and performs necessary comparison processing and the like.

FIG. 2 schematically shows the connection state of the transmission circuit 41, the reception circuit 42, the multiplexer 43 and the touch panel 2.
In the touch panel 2, n transmission signal lines Tx1 to Tx (n) as electrodes on the transmission side are arranged on a panel plane forming a touch surface.
Similarly, on the panel plane, m reception signal lines Rx1 to Rx (m) as electrodes on the reception side are arranged.
When the transmission signal line Tx1 ... Tx (n) and the reception signal line Rx1 ... Rx (m) are not particularly distinguished, they are collectively referred to as "transmission signal line Tx" and "reception signal line Rx".

The transmission signal line Tx1 ... Tx (n) and the reception signal line Rx1 ... Rx (m) may be arranged intersecting each other as shown in the figure, or the so-called single layer structure does not intersect. It may be arranged as such. In any case, the touch operation surface is formed within the range in which the transmission signal line Tx and the reception signal line Rx are arranged, and the operation position is detected by the capacitance change during the touch operation.
The figure illustrates only a part of the capacitance generated between the transmission signal line Tx and the reception signal line Rx (capacities C22, C23, C32, C33), but the transmission signal line Tx and the reception signal are applied to the entire touch operation surface. There is a capacitance generated between the lines Rx (for example, a capacitance at the crossing position), and the position where the capacitance change is generated by the touch operation is detected by the receiving circuit 42.

The transmission circuit 41 outputs a transmission signal to the transmission signal lines Tx1 ... Tx (n) selected by the multiplexer 43. In the present embodiment, the multiplexer 43 performs scanning by selecting two adjacent transmission signal lines Tx at each timing.
The receiving circuit 42 receives the received signal from the received signal lines Rx1 ... Rx (m) selected by the multiplexer 43. In the present embodiment, the multiplexer 43 selects two adjacent reception signal lines Rx at each timing.
The sensing operation by the transmission circuit 41 and the reception circuit 42 will be described later.

Although the sensor IC 4 has been generically described above, when two sensors IC 4A and 4B are used as shown in FIG. 1, the functions of the transmission circuit 41, the reception circuit 42, and the multiplexer 43 in FIG. 2 are the transmission circuits, respectively. It will be shared and realized by 41A, 41B, receiving circuits 42A, 42B, and multiplexers 43A, 43B. Further, the receiving circuits 42A and 42B of each sensor IC have a plurality of (for example, eight) receiving channels. The division of scanning by having a plurality of sensor ICs 4 and a plurality of receiving channels in each sensor IC4 will also be described later.

It will be described back to FIG. The interface register circuit 44 (44A, 44B) of each sensor IC 4 (4A, 4B) has a transmission circuit 41 (41A or 41B), a multiplexer 43 (43A or 43B), and a reception circuit 42 (42A or 42A) in the sensor IC 4. 42B), various setting information for the power supply circuit 45 (45A or 45B) is written by the MCU 5. The MCU 5 transmits the setting information to the interface register circuits 44A and 44B via the bus B1. Specifically, the MCU 5 transmits a chip select signal by a control signal line (not shown) to select one of the interface register circuits 44A and 44B, and instructs writing by a write / read signal, and setting information by the bus B1. Is sent.
The operation of the transmission circuit 41, the multiplexer 43, the reception circuit 42, and the power supply circuit 45 is controlled by the setting information stored in the interface register circuit 44, respectively.
Further, the interface register circuit 44 stores the detected value (also referred to as “RAW value” in the description) detected by the receiving circuit 42 so that the MCU 5 can acquire it via the bus B1.

Further, the MCU 5 transmits a sensing control signal SS to the interface register circuits 44A and 44B.
The setting of the sensor IC4 by the MCU 5 can be performed by writing to the register via the bus B1 as described above, but when a plurality of sensor IC4s are used, the writing to the register by software is performed by each interface register circuit 44A. It may not be possible to execute 44B at the same time. Therefore, if the setting related to the sensing timing is performed by register writing, the timing may be deviated between the sensors IC4A and 4B. Then, the RAW values at the same timing cannot be obtained from the sensors IC4A and 4B, and the correct touch position may not be detected.
Therefore, the sensing control signal SS is used as a hardware-like timing signal. For example, the timing control signal enables the sensors IC 4A and 4B to output the transmission signal (transmission signal T +, T- described later) to the transmission signal line Tx at the same timing, and the sensors IC 4A and 4B are used. However, the RAW value at the same timing can be obtained.

The power supply circuit 45 generates a drive voltage AVCC and supplies it to the transmission circuit 41 and the reception circuit 42. As will be described later, the transmission circuit 41 applies a pulse using the drive voltage AVCC to the transmission signal line Tx selected by the multiplexer 43.
The receiving circuit 42 also applies the drive voltage AVCC to the received signal line Rx selected by the multiplexer 43 during the sensing operation.

The MCU 5 sets and controls the sensor IC 4. As described above, the MCU 5 controls the operation of the sensors IC 4A and 4B by writing necessary setting information to the interface register circuits 44A and 44B of the sensors IC 4A and 4B and transmitting the sensing control signal SS. ..
Further, the MCU 5 acquires the RAW values from the receiving circuits 42A and 42B by reading them from the interface register circuits 44A and 44B. Then, the MCU 5 performs a coordinate calculation using the RAW value, and performs a process of transmitting the coordinate value as the user's touch operation position information to the product side MCU 90.
In FIG. 1, the RAM area, the ROM area, the non-volatile storage area, and the like are collectively shown as the memory 5a in the MCU 5. This memory 5a is used to store the setting information given to the interface register circuits 44A and 44B. Further, the memory 5a also uses the detected RAW value and the coordinate value as the touch operation position information corresponding to the detected RAW value as a temporary storage area.

<2. Sensing operation>
The sensing operation by the touch panel device 1 having the above configuration will be described.
First, the operation of the transmission circuit 41 and the reception circuit 42 with respect to the touch panel 2 will be described with reference to FIG. The figure shows two transmission signal lines Tx2 and Tx3 and two reception signal lines Rx2 and Rx3 on the touch panel 2.

The following sensing operation will be described as the operation of one receiving channel in any one of the sensors IC 4A and 4B.

In the case of the present embodiment, the transmission circuit 41 and the reception circuit 42 transmit and receive two adjacent transmission and reception signals to the transmission signal line Tx and the reception signal line Rx as shown in FIG. By going, the touch operation is detected. That is, the detection scan is sequentially performed in cell units using two × two of the pair of transmission signal lines Tx and the pair of reception signal lines Rx as basic cells. In FIG. 3, the part of the one cell is shown.

The transmission circuit 41 outputs the drive voltage AVCC1 from the drivers 411 and 412 to the two transmission signal lines Tx (Tx2 and Tx3 in the case of the figure). That is, the transmission signals T + and T-, which are the outputs of the drivers 411 and 412, are supplied to the transmission signal lines Tx2 and Tx3 selected by the multiplexer 43.
The drive voltage AVCC 1 is a drive voltage AVCC itself generated by the power supply circuit 45 of FIG. 1 or a voltage based on the drive voltage AVCC.

In this case, the transmission circuit 41 sets the idle (Idle) period as the low level (hereinafter referred to as “L level”) for the transmission signal T + from the driver 411 as shown in the figure. For example, 0V. Then, during the subsequent active period, the level is set to high level (hereinafter referred to as "H level"). In this case, specifically, the drive voltage AVCC1 is applied as the H level signal.
Further, in the transmission circuit 41, the transmission signal T- from the other driver 412 has an idle period of H level (application of drive voltage AVCC1) and a subsequent active period of L level.
Here, the idle period is a period for stabilizing the potentials of the received signals R + and R-, and the active period is a period for sensing the potential changes of the received signals R + and R-.

The logic timings of the H level and L level of the transmission signals T + and T− pulses are set based on, for example, the timing control signal from the MCU 5. For example, the logic of the timing control signal is the same as that of the transmission signal T−.

In the idle period and active period defined by the transmission signals T + and T-, the reception circuit 42 receives reception signals R + and R- from two reception signal lines Rx (Rx3 and Rx2 in the figure) selected by the multiplexer 43. To receive.
The receiving circuit 42 includes a comparator 421, a reference capacitance unit 422, a switch 423, 425, a measurement capacitance unit 424, and an arithmetic control unit 426.
The reception signals R + and R-from the two reception signal lines Rx are received by the comparator 421. The comparator 421 compares the potentials of the received signals R + and R-, and outputs the comparison result to the arithmetic control unit 426 at the H level or the L level.

A drive voltage AVCC2 is applied to one end of a capacitor constituting the reference capacitance portion 422. The drive voltage AVCC 2 is a voltage based on the drive voltage AVCC itself generated by the power supply circuit 45 of FIG. 1 or the drive voltage AVCC. The other end of the capacitor constituting the reference capacitance portion 422 is connected to the + input terminal of the comparator 421 via the terminal Ta of the switch 423.
Further, a drive voltage AVCC2 is applied to one end of the measurement capacitance unit 424. The other end of the measurement capacitance unit 424 is connected to the − input terminal of the comparator 421 via the terminal Ta of the switch 425.

For switches 423 and 425, the terminal Ti is selected during the idle period. Therefore, during the idle period, the + input terminal (received signal line Rx3) and-input terminal (received signal line Rx2) of the comparator 421 are connected to the ground, and the received signals R + and R- become ground potentials.
For switches 423 and 425, the terminal Ta is selected during the active period. Therefore, during the active period, the drive voltage AVCC2 is applied to the + input terminal (received signal line Rx3) and-input terminal (received signal line Rx2) of the comparator 421.

In FIG. 3, the waveforms of the received signals R + and R− when the cell is in the non-touch state are shown by solid lines. In the idle period, the switches 423 and 425 select the terminal Ti, so that the received signals R + and R− are stabilized at a certain potential (ground potential).
In the active period, the switch 423 and 425 select the terminal Ta, so that the drive voltage AVCC2 is applied to the received signal lines Rx3 and Rx2. As a result, the potentials of the received signals R + and R− increase by ΔV. In the non-touch state, this potential increase of ΔV occurs in both the received signals R + and R−.

On the other hand, on the transmission circuit 41 side, during the active period, the transmission signal T + rises and the transmission signal T− falls as described above. As a result, when there is a touch operation, the degree of potential increase of the received signals R + and R− changes.
If the A1 position that affects the capacitance C22 is touched, the potential of the received signal R− rises by ΔVH as shown by the broken line during the active period.
If the A2 position where the capacitance C32 changes is touched, the potential of the received signal R− rises by ΔVL indicated by the broken line during the active period.
As described above, the potential change amount of the received signal R− becomes larger or smaller than the potential change amount (ΔV) of the received signal R + depending on the touch operation position with respect to the cell.
The comparator 421 will compare such received signals R + and R−.

The potential difference itself of the received signals R + and R- changing in this way may be output as a RAW value (detection result), but in the present embodiment, the receiving circuit 42 is received by the arithmetic control unit 426. The setting of the measurement capacitance unit 424 is changed so that the voltage balance of the signals R + and R- can be obtained, and the RAW value is obtained.
The arithmetic control unit 426 performs on / off of the switches 423 and 425 and switching of the capacity value of the measurement capacity unit 424 according to the setting information written in the interface register circuit 44. Further, the output of the comparator 421 is monitored, and the RAW value is calculated by the process described later. The RAW value calculated by the arithmetic control unit 426 is written to the interface register circuit 44 so that the MCU 5 can acquire it.

The measurement capacitance unit 424 indicated by the symbol of the variable capacitor in FIG. 3 is composed of a plurality of capacitance units CM (CM0 to CM7) and switches SW (SW0 to SW7) as shown in FIG. 4, for example.
Note that FIG. 4 shows an equivalent circuit in a state where the switches 423 and 425 are connected to the terminal Ta (active period), and the switches 423 and 425 are not shown.
The capacitance units CM0 to CM7 are connected in parallel between the potential of the drive voltage AVCC2 and the-input terminal of the comparator 421. Further, switches SW0 to SW7 are connected in series to each of the capacitance units CM0 to CM7. That is, by turning on / off the switches SW0 to SW7, the capacitance part CM that affects the received signal R- can be changed.
Further, the switches SW0 to SW7 are each configured by using a switch element such as a FET (Field effect transistor), but a plurality of switch elements may be provided as one switch SW.

The capacity values of the capacity units CM0 to CM7 are, for example, capacity units CM0 = 2fF (femtofarad), CM1 = 4fF, CM2 = 8fF, CM3 = 16fF, CM4 = 32fF, CM5 = 64fF, CM6 = 128fF, CM7 = 256fF. Will be done.
In FIG. 4, each of the capacitors CM0 to CM7 is composed of one capacitor, but all or part of each of the capacitors CM0 to CM7 is composed of a plurality of capacitors, and the combined capacitance is the same as the above capacitance value. It may be.
The capacitance units CM0 to CM7 are selected by 8-bit values of bits "0" to "7". The capacitance unit CM0 and the switch SW0 function as a bit “0”, the capacitance unit CM1 and the switch SW1 function as a bit “1”, and the capacitance unit CM7 and the switch SW7 function as a bit “7”.
Then, a capacity setting value from 0 (= "0000000000") to 255 (= "111111111") is given as an 8-bit value. The capacity setting value is one of the setting information written by the MCU 5 to the interface register circuit 44.
In the receiving circuit 42, the switches SW0 to SW7 are turned on / off according to the 8-bit capacity setting value. That is, the switches SW0 to SW7 are turned off when the corresponding bit is "0" and turned on when the corresponding bit is "1". As a result, the total capacity value of the measurement capacity unit 424 is changed in 256 steps in the range of 0fF to 510fF.

On the other hand, the capacitance value of the capacitor of the reference capacitance section 422 on the reception signal R + side is, for example, 256 fF.

As described above, the degree of potential increase of the waveform of the received signal R- in the active period changes depending on the presence / absence and position of touch. It becomes larger or smaller than the waveform rise degree (ΔV) of the received signal R +.
In the configuration of FIG. 4, the degree of potential increase of the waveform of the received signal R- can be changed by changing the capacity set value of the measuring capacity unit 424, for example, the measuring capacity equivalent to that of the received signal R +. The capacity setting value of the unit 424 can be found.
For example, assuming that the waveform Sg1 shown by the broken line of the received signal R- in FIG. 4 is in the initial state, if the capacity of the measuring capacitance unit 424 is reduced, the received signal R- becomes smaller than the waveform Sg1 like the waveform Sg2. .. Further, if the capacity of the measurement capacity unit 424 is increased, the received signal R- becomes larger than the waveform Sg1 like the waveform Sg3.
That is, the capacity setting value of the measurement capacitance unit 424 when the voltage levels of the received signals R + and R− are the same in the comparator 421 is equivalent to the value corresponding to the voltage change of the received signal R− due to the touch. Therefore, while observing the output of the comparator 421, the capacity setting value of the measurement capacity unit 424 is changed, and the capacity setting value at which the voltages of the received signals R + and R- during the active period are the same is searched for. Then, the searched capacity setting value can be used as the RAW value as the sensing information of the touch operation.

The specific procedure of the above sensing operation will be described with reference to FIG. FIG. 5 shows processing mainly performed in the transmission circuit 41 and the reception circuit 42 based on various setting information written by the MCU 5 in the interface register circuit 44 and the sensing control signal SS.
Further, FIG. 6 shows the state of the sensing control signal SS corresponding to each step of FIG. In FIG. 6, the processes shown by the thick frames W1 and W2 are the processes for generating the sensing control signal SS in the MCU 5, and the other processes show the states of the sensing control signal SS. "High" is the H level and "Low" is the L level. The logic of the sensing control signal SS is the same as that of the transmission signal T-. That is, the transmission signal T-is a signal having the same logic as the sensing control signal SS, and the transmission signal T + is a signal obtained by inverting the logic of the sensing control signal SS.
Hereinafter, in the description of each step of FIG. 5, the sensing control signal SS shown in FIG. 6 will also be referred to.

In FIG. 5, the loop processing of steps S100 to S110 shows a sensing procedure for one cell (a set of two transmission signal lines Tx and two reception signal lines Rx). By the time the RAW value is obtained, the capacity setting value takes 8 different values (changed 7 times from the initial state).

In step S100, the variable n is first set to n = 7 as an initial value. Further, the receiving circuit 42 sets the capacity value of the measurement capacity unit 424 to 256 fF based on the instruction (capacity set value) of the MCU 5. That is, the capacity setting value = 128 (= 1000000), and since only the bit “7” is “1”, only the switch SW7 is turned on.
The sensing control signal SS is H level.

In step S101, the input / output settings of all the terminals in the multiplexer 43 are set. This particularly selects the transmission signal line Tx that outputs the transmission signals T + and T-, and selects the reception signal line Rx that receives the reception signals R + and R-.
In particular, since the settings for supporting a plurality of sensor ICs are included, the details will be described later.

In step S102, the idle period is set.
As shown in FIG. 6, the sensing control signal SS by the MCU5 has maintained the H level until then, but at the time of this step S102, the MCU5 starts the time count (Timer count1) and continues to maintain the H level during that time. (See thick frame W1).
In response to this, in the transmission circuit 41, the transmission signal T + from the driver 411 is set to the L level, and the transmission signal T- is set to the H level (= drive voltage AVCC1).
In the receiving circuit 42, the switches 423 and 425 are connected to the terminal Ti. As a result, the + input terminal and the-input terminal of the comparator 421 are connected to the ground.

Next, in step S103 of FIG. 5, switching from the idle period to the active period is performed by the lapse of a predetermined period by the time count (Timer count1).
As shown in FIG. 6, the MCU 5 starts a time count (Timer count2) so that the L level is maintained during that time (see thick frame W2).
Accordingly, in the transmission circuit 41, the transmission signal T + from the driver 411 is set to H level (= drive voltage AVCC1), and the transmission signal T- from the driver 412 is set to L level.
In the receiving circuit 42, the switches 423 and 425 are connected to the terminal Ta. As a result, the + input terminal of the comparator 421 is connected to the drive voltage AVCC2 via the reference capacitance unit 422, and the-input terminal is connected to the drive voltage AVCC2 via the measurement capacitance unit 424.

During the active period, the received signals R + and R- increase by ΔV, but the transmitted signal T + rises and the transmitted signal T- falls, so that the received signal R according to the presence / absence of a touch operation on the cell being detected and the touch operation position. -A change occurs (the amount of increase is ΔVH or ΔVL).
During this active period, as shown in step S104 of FIG. 5, the comparator 421 compares the received signals R + and R− and outputs the comparison result. From the comparator 421, an H level output is obtained if (received signal R +)> (received signal R−), and an L level output is obtained if (received signal R +) <(received signal R−).

After that, when a predetermined time by the time count (Timer count2) elapses, the sensing control signal SS is set to the H level at the timing of step S105 as shown in FIG. 6, and then the comparator result is read after step S105 in FIG. Is done.

In step S105, the process is branched according to the output of the comparator 421.
If the output of the comparator 421 is H level, the capacitance of the measurement capacitance unit 424 is switched in step S106. In this case, the switch of the bit "n-1" is turned on while the switch of the bit "n" is kept on.
Until then, when the capacity setting value = "10000000" and only the bit "7" was turned on in the initial state as described above, the capacity setting value = "11000000" was subsequently set and the bit "7" and the bit "6" were turned on. Is turned on. That is, the switches SW7 and SW6 are turned on, and the capacity value of the measurement capacity unit 424 is 384fF.
If the variable n> 0 in step S108, the variable n is decremented in step S109 and the process returns to step S102. That is, after increasing the capacity of the measurement capacity unit 424, the operation during the idle period and the active period described above is performed to confirm the output of the comparator 421.

If the output of the comparator 421 is L level in step S105, the capacity of the measurement capacitance unit 424 is switched in step S107. In this case, the switch of the bit "n" is turned off and the switch of the bit "n-1" is turned on.
If the capacity setting value = "10000000" is set and only the bit "7" is turned on in the initial state, then the capacity setting value = "01000000" is set and the bit "7" is turned off and the bit "6" is turned on. Is turned on. That is, the switch SW7 is turned off, the switch SW6 is turned on, and the capacity value of the measurement capacity unit 424 is 128 fF.
If the variable n> 0 in step S108, the variable n is decremented in step S109 and the process returns to step S102. That is, after reducing the capacity of the measuring capacity unit 424, the operation during the idle period and the active period described above is performed to confirm the output of the comparator 421.

By performing this process until the variable n = 0, the capacity setting value when the voltage value in the active period of the received signal R− and the voltage value in the active period of the received signal R + are balanced is determined.
Since the bit "n-1" does not exist in steps S106 and S107 when the variable n = 0, the processing of the bit "n-1" is not performed.
If the variable n = 0 in step S108, the process proceeds to step S110, and the receiving circuit 42 calculates the RAW value. This is a process of taking the sum of the powers of 2 of the bits of the switch SW that are turned on in the measurement capacitance unit 424. For example, if the switches SW5, SW3, and SW2 were finally turned on, ²⁵ +2 ³ +2 ² = 44, and the RAW value = 44.

The RAW value thus obtained is acquired by the MCU 5 as a detection value of one cell via the interface register circuit 44.
The processing of FIG. 5 is similarly performed for each cell (a set of two transmission signal lines Tx and two reception signal lines Rx) on the touch panel 2, and a RAW value is obtained.
The MCU 5 acquires the RAW value for each cell, calculates the coordinate of the touch operation position, and transmits the obtained coordinate value to the MCU 90 on the product side.

In the present embodiment, as the sensing operation as described above, by taking the difference between the received signals R + and R-, the acquired RAW value can be made less likely to be affected by the external environment, and the touch operation can be performed. Detection accuracy can be improved.
In particular, when not touched, the potentials of the received signals R + and R-are balanced, and the potentials of the received signals R + and R- are different due to the capacitance change due to the touch. The capacity of the measurement capacity unit 424 is sequentially changed to search for a capacity value in which the received signals R + and R- are balanced, and the RAW value is obtained from the capacity setting value for which the capacity value is specified. As a result, the difference between the received signals R + and R- caused by the capacitance change due to the touch operation can be accurately detected.

There are mainly two reasons for charging the selected reception signal line Rx by applying the drive voltage AVCC2 from the reception circuit 42.
One is the situation when the touch panel 2 has a single layer structure. In the case of the single layer structure, in the non-touch state, almost no capacitance is generated between the transmission signal line Tx and the reception signal line Rx. That is, the space between the transmission signal line Tx and the reception signal line Rx (between the electrodes) is in an insulated state. However, even in the non-touch state, it is necessary to make the received signal waveform rise during the active period. For this reason, by transmitting the drive voltage AVCC2, the above-mentioned sensing operation can be performed satisfactorily even in the case of a single layer.
Another reason is not limited to single layers. In the above sensing method, the potential increase width of the received signal R- is seen from the transition to the active period, but it is also desired to understand the influence of the falling edge of the transmitted signal T-. That is, it is necessary to observe the potential increase of ΔVL shown by the broken line in FIG. If the potentials of the received signals R + and R- in the non-touch state during the active period are 0 V, the potential of the received signal R- becomes a negative value when affected by the falling edge, and is handled by the receiving circuit 42. It will be difficult. Therefore, the potential of the received signal R- is raised so as not to be 0 V or less, and the drive voltage AVCC2 is applied to facilitate the easy and appropriate observation of the potential of the received waveform due to the influence of the falling edge of the transmitted signal T-. are doing.

By the way, in the present embodiment, the sensors IC 4A and 4B each have a plurality of receiving channels, and each receiving channel performs the above-mentioned sensing operation.
This will be described with reference to FIG. FIG. 7 shows a case where one sensor IC 4 has a plurality of receiving channels ch1 ... Chx. In this case, the above-mentioned comparator 421 is shown as each receiving channel ch1, ch2 ... That is, the configuration shown in FIG. 4 corresponds to one receiving channel.

FIG. 7A shows a state in which the transmission signals T + and T− are output to the transmission signal lines Tx1 and Tx2 by the drivers 411 and 412.
At this time, the reception signal lines Rx1 and Rx2 are connected to the reception channel ch1, and the reception signals R + and R− are supplied to the comparator 421 of the reception channel ch1.
Further, the reception signal lines Rx (p) and Rx (p + 1) are connected to the reception channel ch2, and the reception signals R + and R− are supplied to the comparator 421 of the reception channel ch2.
Similarly, the reception signal lines Rx (q) and Rx (q + 1) are connected to the reception channel chx, and the reception signals R + and R− are supplied to the comparator 421 of the reception channel chx.
Therefore, when scanning the transmission signal lines Tx1 and Tx2, sensing can be performed simultaneously on the x reception channels ch1 ... Chx.

At the next timing, the transmission signal line Tx to be scanned is shifted while maintaining the connection relationship between the reception signal line Rx and each reception channel ch1 ... chx. That is, although not shown, transmission signals T + and T− are output to transmission signal lines Tx2 and Tx3, and sensing is simultaneously performed on x reception channels ch1 ... Chx during this period.
FIG. 7B shows a state in which the scanning target of the transmission signal line Tx has reached the final line.
That is, the transmission signals T + and T-are output to the transmission signal lines Tx (n-1) and Tx (n), and sensing is simultaneously performed on the x reception channels ch1 ... Chx during this period.

At the next timing, the transmission signal line Tx to be scanned is returned to the transmission signal lines Tx1 and Tx2, and the reception signal line Rx connected to each reception channel ch1 ... chx is shifted. That is, the reception signal lines Rx1 and Rx2 are connected to the reception channel ch1, and the reception signal lines Rx (p + 1) and Rx (p + 2) are connected to the reception channel ch2. Similarly, the reception signal lines Rx (q + 1) and Rx (q + 2). Is connected to the receive channel chx. As a result, sensing is performed on the reception channels ch1 ... chx.

After that, the transmission signal line Tx to be scanned is shifted while maintaining the connection relationship between the reception signal line Rx and each reception channel ch1 ... chx.

By the above operation, when the transmission signals T + and T- are output to the pair of transmission signal lines Tx, sensing is performed simultaneously on a plurality of reception channels, so that the panel becomes large and the sensing cells increase. Sensing can be performed efficiently.
However, in such a case, the number of RAW values that can be read out at the same time is limited by the number of receiving channels included in the sensor IC 4. For example, if the sensor IC 4 has eight receiving channels, only eight RAW values can be read at the same time. Therefore, in order to perform efficient sensing even for a larger panel, a plurality of sensors IC4A and 4B are used as shown in FIG. In this case, the RAW value can be read simultaneously on 16 receiving channels.

When a plurality of sensors ICs 4A and 4B are actually used for a large touch panel, the allocations shown in FIGS. 8 and 9 can be considered.
FIG. 8 is an example in which the sensor IC 4A is used exclusively for transmission and the sensor IC 4B is used exclusively for reception. However, if this is done, the reception channel of the sensor IC4A cannot be used.
Therefore, the assignment is as shown in FIG.

In the case of FIG. 9, the sensor IC 4A is in charge of receiving the left half area of the touch panel 2 and is also in charge of transmitting the lower half area.
Further, the sensor IC 4B is in charge of receiving the right half area of the touch panel 2 and is also in charge of transmitting the upper half area.
In this way, for example, simultaneous sensing of 16 channels becomes possible. As a result, the time required to acquire the RAW value of one screen sentence can be shortened, which is suitable for a large panel.

However, when a plurality of sensor ICs 4 are used, there arises a problem that the position detection accuracy is lowered in the boundary region where the respective sensors IC4A and 4B are in charge of each sensor IC4A and 4B in the received signal line Rx.
FIG. 10A schematically shows the state of sensing at the boundary portion. The received signal lines Rx (k-1), Rx (k), Rx (k + 1), and Rx (k + 2) are shown, and the received signal lines Rx (k-1) and Rx (k) are handled by the sensor IC4A. It is assumed that the sensor IC4B is in charge of Rx (k + 1) and Rx (k + 2).

Sensing for the pair of received signal lines Rx needs to be performed in one receiving channel of one sensor IC4. This is to obtain the RAW value by the procedure of FIG. 5 in the configuration of FIG.
In the case of FIG. 10A, the received signals R- and R + at the time of scanning the received signal lines Rx (k-1) and Rx (k) can be compared by the comparator 421 of the sensor IC 4A.
Further, the received signals R− and R + at the time of scanning the received signal lines Rx (k + 1) and Rx (k + 2) can be compared by the comparator 421 of the sensor IC 4B.
However, assuming a set of received signal lines Rx (k) and Rx (k + 1), the received signal R + is input to the sensor IC4A and the received signal R- is input to the sensor IC4B as shown in FIG. 10B. It ends up.
That is, the region corresponding to the set of the received signal lines Rx (k) and Rx (k + 1) is a region that cannot be sensed, and the RAW value cannot be obtained, so that the sensing accuracy is lowered. Further, even if an attempt is made to sense as shown in FIG. 10B, a correct RAW value cannot be obtained because the received signals R + and R- straddle another sensor IC4A.

In the present embodiment, the RAW value can be correctly detected even at such a boundary portion, so that the sensing accuracy can be maintained even when a plurality of sensors IC4A are used.

<3. First Embodiment>
A specific configuration and operation as the first embodiment will be described.
11A and 11B schematically show the concept of the first embodiment.
The figure shows the received signal lines Rx (k), Rx (k + 1), and Rx (k + 2).
In this case, the received signal lines Rx1 to Rx (k) arranged in the left side region of the touch panel 2 are connected only to the sensor IC 4A.
Further, the received signal lines Rx (k + 2) to Rx (m) arranged in the right side region of the touch panel 2 are configured to be connected only to the sensor IC 4B.
The received signal line Rx (k + 1) can be connected to both the sensors IC4A and 4B.

That is, the sensor IC 4A is capable of sensing scanning with respect to the reception signal line group G1 from the reception signal line Rx1 to Rx (k + 1). Further, the sensor IC 4B is capable of sensing scanning with respect to the received signal line group G2 from the received signal line Rx (k + 1) to Rx (m).
Here, the received signal line group G1 is a part of all the received signal lines Rx, and is a plurality of received signal lines Rx continuously arranged in an adjacent state. The reception signal line group G2 is also a part of all the reception signal lines Rx, and is a plurality of reception signal lines Rx arranged continuously in an adjacent state, but only the reception signal line Rx (k + 1) is used. It shall be common with the received signal line group G1.
The reception signal line Rx (k + 1) included in both the reception signal line groups G1 and G2 is the boundary reception signal line.

Then, when sensing the set of the received signal line Rx (k) and Rx (k + 1), the received signal line Rx (k + 1) is connected to the sensor IC4A as shown in FIG. 11A, and N / C for the sensor IC4B. (Non Connection).
When sensing the set of received signal lines Rx (k + 1) and Rx (K + 2), connect the received signal lines Rx (k + 1) to the sensor IC4B as shown in FIG. 11B, and use N / C for the sensor IC4A. do.

That is, the function of disconnecting the terminal connection of the sensor IC4 is provided, and the lead-out wiring of the boundary reception signal line Rx (k + 1) corresponding to the boundary of the division of the sensors IC4A and 4B is branched to the sensors IC4A and 4B. Connecting. The wiring may be branched on the touch panel 2 or on a board (FPC (Flexible printed circuits), PCB (Printed Circuit Board), etc.) attached to the touch panel 2. In addition, it has a function to make the branched wiring N / C.
By enabling the sensors IC 4A and 4B to connect the boundary reception signal line Rx (k + 1) in this way, it is possible to prevent a region (cell) that cannot be sensed at the boundary portion of the division.

This will be specifically described using the model of FIG. For the sake of brevity, the operation of each of the sensors IC4A and 4B will be described as the operation of a certain receiving channel.

FIG. 12 shows the sensors IC4A and 4B shown in FIG. 1 and the MCU5. In the touch panel 2, eight transmission signal lines Tx1 ... Tx8 and nine reception signal lines Rx1 ... Rx9 are shown as explanatory models.
The reception signal lines Rx1 to Rx5 are referred to as a first reception signal line group G1, and the reception signal lines Rx5 to Rx9 are referred to as a second reception signal line group G2. Therefore, the reception signal line Rx5 becomes the boundary reception signal line.

Transmission signal lines Tx1, Tx2, Tx3, and Tx4 are connected to the terminals TS11, TS12, TS13, and TS14 of the multiplexer 43A.
Further, the reception signal lines Rx1, Rx2, Rx3, and Rx4 are connected to the terminals TS15, TS16, TS17, and TS18. The branch wiring Rx51 of the reception signal line Rx5 is connected to the terminal TS19.

Transmission signal lines Tx5, Tx6, Tx7, and Tx8 are connected to the terminals TS21, TS22, TS23, and TS24 of the multiplexer 43B.
The reception signal lines Rx6, Rx7, Rx8, and Rx9 are connected to the terminals TS26, TS27, TS28, and TS29. The branch wiring Rx52 of the reception signal line Rx5 is connected to the terminal TS25.

Assuming this configuration, the setting process for switching the signal path to the multiplexers 43A and 43B by the MCU5 at each timing in the process of sensing scanning for one screen will be described with reference to FIGS. 13 and 5. The timing of these switching controls refers to the timing at which the sensing of the cell defined by a certain set of received signal lines Rx and a certain set of transmitted signal lines Tx is started.

First, the set of transmission signal lines Tx1 and Tx2 is selected, sensing with the set of reception signal lines Rx1 and Rx2 on the sensor IC4A side, and the timing TM1 for sensing the set of reception signal lines Rx5 and Rx6 on the sensor IC4B side. Focus on it. That is, it is the timing for sensing the cells CE1A and CE1B.
In this timing TM1, the setting on the receiving side with respect to the multiplexer 43A on the sensor IC4A side performed in step S101 of FIG. 5 is as follows (see FIG. 13).
-Set the terminal TS15 to be the received signal R + when active-Set the terminal TS16 to be the received signal R- when active-Set the terminal TS19 to N / C

The settings on the receiving side of the multiplexer 43B on the sensor IC 4B side are as follows.
-Set the terminal TS25 to be the received signal R + when active.-Set the terminal TS26 to be the received signal R- when active.

Then, in the multiplexer 43A, the terminals TS11 and TS12 are set to the transmission signals T + and T−.
After the above setting is performed in step S101 of FIG. 5, the processing of step S110 is performed from step S102, so that the cells CE1A and CE1B of FIG. 12 are sensed.

At the next timing, the terminal settings on the transmitting side are switched while maintaining the terminal settings on the receiving side of the multiplexers 43A and 43B. That is, in step S101 of FIG. 5, the terminals TS12 and TS13 are set to the transmission signals T + and T− in the multiplexer 43A, and sensing is similarly performed in step S102 and subsequent steps.

At the next timing, the multiplexer 43A sets the terminals TS13 and TS14 to the transmission signals T + and T-, and sensing is performed.
At the next timing, the terminal T14 is set to the transmission signal T + in the multiplexer 43A, and the terminal TS21 is set to the transmission signal T− in the multiplexer 43B, and sensing is performed.
At the next timing, the multiplexer 43B sets the terminals TS21 and TS22 to the transmission signals T + and T-, and sensing is performed.
At the next timing, the multiplexer 43B sets the terminals TS22 and TS23 to the transmission signals T + and T-, and sensing is performed.
At the next timing, the multiplexer 43B sets the terminals TS23 and TS24 to the transmission signals T + and T-, and sensing is performed.

This completes the sensing of each cell for the set of the received signal lines Rx1 and Rx2 and the set of the received signal lines Rx5 and Rx6.
The terminals not mentioned in the multiplexers 43A and 43B (terminals not used for scanning the cell at that time) are connected to the ground. The same applies to each timing described below.

Next, in the timing TM2 in which the sensor IC 4A side senses the set of the received signal lines Rx2 and Rx3 and the sensor IC 4B side senses the set of the received signal lines Rx6 and Rx7, the timing TM2 with respect to the multiplexers 43A and 43B in step S101 of FIG. The setting process on the receiving side is as follows (see FIG. 13).
-Set the terminal TS16 to be the received signal R + when active-Set the terminal TS17 to be the received signal R- when active-Set the terminal TS26 to be the received signal R + when active-Receive the terminal TS27 when active Set the signal R-, and set the terminals TS11 and TS12 to the transmission signals T + and T- in the multiplexer 43A as the setting on the transmission side.
After the above settings are made, sensing is performed in the processes of steps S102 to S110.

After that, the terminal settings of the transmission signals T + and T- are shifted to terminals TS11, TS12, terminals TS12, TS13 ... Terminals TS23, TS23 in the same manner as in the above timing TM1 and later, while sensing in each region is performed. It will be done.

Next, in the timing TM3 in which the sensor IC 4A side senses the set of the received signal lines Rx3 and Rx4 and the sensor IC 4B side senses the set of the received signal lines Rx7 and Rx8, the timing TM3 with respect to the multiplexers 43A and 43B in step S101 of FIG. The setting process on the receiving side is as follows (see FIG. 13).
-Set the terminal TS17 to be the received signal R + when active-Set the terminal TS18 to be the received signal R- when active-Set the terminal TS27 to be the received signal R + when active-Receive the terminal TS28 when active Set the signal R-, and set the terminals TS11 and TS12 to the transmission signals T + and T- in the multiplexer 43A as the setting on the transmission side.
After the above settings are made, sensing is performed in the processes of steps S102 to S110.

Further, after that, sensing in each region is performed while the terminal settings of the transmission signals T + and T- are shifted in the same manner as in the above timing TM1 and later.

Next, pay attention to the timing TM4 in which the sensor IC 4A side senses the set of the received signal lines Rx4 and Rx5, and the sensor IC 4B side senses the set of the received signal lines Rx8 and Rx9. That is, it is the timing for sensing the cells CE4A and CE4B.
At this time, the setting process on the receiving side for the multiplexers 43A and 43B in step S101 of FIG. 5 is as follows (see FIG. 13).
-Set the terminal TS18 to be the received signal R + when active-Set the terminal TS19 to be the received signal R- when active-Set the terminal TS28 to be the received signal R + when active-Receive the terminal TS29 when active Set the signal R- to be set.-Set the terminal TS25 to N / C. Also, as the setting on the transmitting side, set the terminals TS11 and TS12 to the transmission signals T + and T- in the multiplexer 43A.
After the above settings are made, sensing is performed in the processes of steps S102 to S110.

Further, after that, sensing in each region is performed while the terminal settings of the transmission signals T + and T- are shifted in the same manner as in the above timing TM1 and later.

By the above procedure, scanning for one screen of the touch sensor 2 is performed. In this case, there are no regions (cells) on the left and right of the boundary reception signal line Rx5 where the RAW value cannot be appropriately obtained. As understood as the case of the timing TM4 and TM1 described above, the sensing for the set of the received signal lines Rx4 and Rx5 is normally performed by the receiving circuit 42A, and the sensing for the set of the received signal lines Rx5 and Rx6 is performed by the receiving circuit. This is because it is normally performed by 42B.

The settings for the multiplexers 43A and 43B as described above may not be performed at the same time. By defining the timing of the transmission signals T + and T- by the sensing control signal SS as described in FIG. 6, the RAW values by the sensors IC4A and 4B can be obtained at the same time.

<4. Second Embodiment>
The configuration and operation of the second embodiment will be described with reference to FIG.
In the figure, the reception signal lines Rx (k), Rx (k + 1), and Rx (k + 2) are shown, but the reception signal line Rx (k + 1) is the boundary reception signal line. The reception signal lines Rx1 to Rx (k + 1) are considered to be the reception signal line group G1, and the reception signal lines Rx (k + 1) to Rx (m) are considered to be the reception signal line group G2.

In this case, the received signal lines Rx1 to Rx (k) arranged in the left side region of the touch panel 2 are connected to the terminals of the multiplexer 43A of the sensor IC 4A.
Further, the received signal lines Rx (k + 1) to Rx (m) arranged in the right side region of the touch panel 2 are connected to the terminals of the multiplexer 43B of the sensor IC 4B.

Here, the received signal line Rx (k + 1) is connected to the terminal TSa of the multiplexer 43B. The terminal TSb of the multiplexer 43B is connected to the terminal TSc of the multiplexer 43A by wiring. By setting the multiplexer 43B to connect the terminal TSa and the terminal TSb, the received signal line Rx (k + 1) can be connected from the terminal TSc to the sensor IC4A side.

That is, the multiplexer 43A of the sensor IC 4A can connect its external input terminal to the comparator 421 by the terminal setting as described in the first embodiment including the terminal TSc.
As a result, the reception signal R-from the boundary reception signal line Rx (k + 1) can be input, so that the reception circuit 42A can sense the set of the reception signal lines Rx (k) and Rx (k + 1). In this case, on the multiplexer 43B side, it is conceivable to set the capacitor setting for capacitance detection to 0 so that the receiving circuit 42B does not function.

At the timing of sensing the set of received signal lines Rx (k + 1) and Rx (k + 2), the multiplexer 43B is set to disconnect the terminal TSa and the terminal TSb, and the terminal TSa is set to be the received signal R + when it is active. Then, the terminal connected to the reception signal line Rx (k + 2) is set to be the reception signal R- when active. As a result, sensing can be performed by the receiving circuit 42B.

By doing so, there are no cells in which the RAW value cannot be appropriately obtained on the left and right of the boundary reception signal line Rx (k + 1).

<5. Summary and modification>
According to the touch panel device 1 or the touch panel drive device 3 of the above embodiment, the following effects can be obtained.
In the embodiment, when the received signal line groups G1 and G2 in which only the boundary received signal lines overlap are considered, the sensing scan can be performed on each received signal line Rx of the received signal line group G1. The receiving circuit 42A is provided with the receiving circuit 42A, which is another IC chip and is configured so that sensing scanning can be performed on each receiving signal line Rx of the receiving signal line group G2. Further, an MCU 5 (control unit) that controls switching of signal paths so that the received signals by the boundary received signal lines included in the received signal line groups G1 and G2 are supplied to the receiving circuits 42A and 42B at different timings is provided. Be prepared.
Since the receiving circuits 42A and 42B are both configured to be capable of scanning the boundary reception signal line for sensing, it is possible to eliminate the occurrence of a region where sensing cannot be performed at the boundary portion of each sensor IC 4A and 4B. become. Therefore, when a plurality of sensor ICs 4 are used in a large panel, the sensing accuracy is not deteriorated, which is preferable.
Then, in the example of FIG. 12, in the timing TM4 for supplying the received signal of the boundary reception signal line Rx5 to the reception circuit 42A of the sensor IC4A, the reception signal line Rx5 (wiring Rx52) is used for the sensor IC4B. ) Is set to N / C, and in the timing TM1 in which the received signal of the received signal line Rx5 is supplied to the receiving circuit 42B of the sensor IC4B, the received signal line Rx5 (wiring Rx51) is N / C with respect to the sensor IC4A. C is set. That is, the signal path switching control is performed so that the received signal by the boundary reception signal line Rx5 is supplied to the receiving circuits 42A and 42B at different timings. As a result, each of the receiving circuits 42A and 42B can perform sensing using the boundary receiving signal line Rx5 in the same manner as the other receiving signal line Rx without being affected by the other sensor IC, and the sensing accuracy is also in this respect. It becomes suitable for maintenance of.

Although the received signal line groups G1 and G2 have been described in the example of sensing with two sensors IC4A and 4B, it is also possible to divide the received signal line groups into three or more received signal line groups and sense them with three or more sensor IC4s.
For example, 24 channels can be simultaneously sensed by using three sensors IC4A, 4B, and 4C (not shown) having 8 channels for receiving signal lines G1, G2, and G3 (not shown) separately. Also in that case, the sensors IC4A and 4B are controlled as in the embodiment with respect to the boundary reception signal lines for the reception signal line groups G1 and G2, and the sensor IC4B and the sensor IC4B for the boundary reception signal lines for the reception signal line groups G2 and G3. By controlling the 4C as in the embodiment, it is possible to prevent the sensing accuracy from being lowered.
That is, even when three or more sensor ICs 4 are provided and three or more receiving circuits 42 are provided, when two of them are viewed, they are regarded as the first receiving circuit and the second receiving circuit of the present invention, and the signal path is set by the MCU 5. Any configuration may be used as long as switching control is performed.

In the embodiment, a pair of received signal lines Rx are sequentially selected and connected to each of the receiving circuits 42A and 42B by the multiplexers 43A and 43B in the process of scanning, and the MCU 5 controls switching. Was determined by setting the terminals for the multiplexers 43A and 43B.
In the case of a configuration in which the reception signal line Rx is connected to the reception circuits 42A and 42B via the multiplexers 43A and 43B, the signal path of the reception signal line Rx5 can be easily switched by setting the terminals for the multiplexers 43A and 43B for each timing. can. Further, it is not necessary to separately provide wiring for the boundary reception signal line including the switching path.
Further, since the MCU5 manages the settings of all terminals including the terminal settings of the multiplexers 43A and 43B at each timing shown in FIG. 13 and the terminal settings (not shown), the sensors IC 4A and 4B are set at each timing. May be operated according to the instruction of the MCU 5, and can be applied to the same one type of IC. This is also convenient when three or more sensor ICs 4 are provided.

In the first embodiment, when the MCU 5 connects the boundary reception signal line to the reception circuit 42A by the multiplexer 43A, the FIFO makes the boundary reception signal line unconnected to the reception circuit 42B by the multiplexer 43B. When the boundary reception signal line is connected to the reception circuit 42B by the multiplexer 43B, the boundary reception signal line is disconnected from the reception circuit 42A by the multiplexer 43A.
As a result, the boundary reception signal line becomes the reception signal line Rx connected only to the reception circuit 42A when sensed by the reception circuit 42A, and the reception signal connected only to the reception circuit 42B when sensed by the reception circuit 42B. It becomes the line Rx. Therefore, the receiving circuits 42A and 42B can execute the sensing for the set including the boundary receiving signal line under the same conditions as the other receiving signal lines Rx and without the influence of the other receiving circuit system. As a result, it is possible to prevent the detection accuracy from being lowered with respect to the pair of sensing including the boundary reception signal line.

In the second embodiment, when the boundary reception signal line is connected to the reception circuit 42A, the MCU 5 controls the multiplexer 43B to connect the boundary reception signal line to the specific terminal TSc of the multiplexer 43A, and also controls the multiplexer 43B. The multiplexer 43A is controlled to connect a specific terminal TSc to the receiving circuit 42A.
As a result, even when the boundary reception signal line is connected to one of the multiplexers 43B, the signal path can be switched to a state in which the reception circuit 42A can sense. This is suitable when there is a situation in which it is difficult to form a branch wiring between the touch sensor 2 and the multiplexer 43 as the wiring of the boundary reception signal line.

Although the touch panel device 1 of the embodiment has been described as performing a touch operation that actually touches the panel surface, the present invention is a touch panel corresponding to so-called hover sensing (non-contact proximity operation) that performs an operation equivalent to a touch. The present invention also includes an apparatus, and the present invention can be applied in that case as well. That is, the "touch" in the present invention and the embodiment also includes a non-contact proximity operation state.

Further, the configuration and operation of the embodiment are examples. In the present invention, various configuration examples and operation examples can be considered. For example, the receiving circuit 42 and the measuring capacitance unit 424 are not limited to the configuration shown in FIG. Further, the sensor IC 4 (4A, 4B) has a transmission circuit 41, a reception circuit 42, a multiplexer 43, an interface register circuit 44, and a power supply circuit 45, some of which are provided outside the IC chip. You may.

1 Touch panel device 2 Touch panel 3 Touch panel drive device 4, 4A, 4B Sensor IC
5 MCU
Tx, Tx1 ... Tx (n) Transmission signal line Rx, Rx1 ... Rx (m) Reception signal line 41, 41A, 41B Transmission circuit 42, 42A, 42B Reception circuit 43, 43A, 43B multiplexer 44, 44A, 44B interface register circuit 45, 4A, 45B power supply circuit

In the above-mentioned touch panel drive device and touch panel device, the first receiving circuit selectively selects a terminal to which each reception signal line of the first reception signal line group excluding the boundary reception signal line is connected and a specific terminal. A first multiplexer connected to the above, and a second multiplexer for selectively connecting a terminal to which each reception signal line of the second reception signal line group is connected to the second reception circuit are provided. When connecting the boundary reception signal line to the first receiving circuit, the control unit controls the second multiplexer to connect the boundary reception signal line to the specific terminal of the first multiplexer. At the same time, it is conceivable to control the first multiplexer to connect the specific terminal to the first receiving circuit.
The boundary reception signal line is connected to one multiplexer, but it can also be connected to the other multiplexer by wiring between the multiplexers.

By the above procedure, scanning for one screen of the touch panel 2 is performed. In this case, there are no regions (cells) on the left and right of the boundary reception signal line Rx5 where the RAW value cannot be appropriately obtained. As is understood as the case of the timing TM4 and TM1 described above, the sensing for the set of the received signal lines Rx4 and Rx5 is normally performed by the receiving circuit 42A, and the sensing for the set of the received signal lines Rx5 and Rx6 is performed by the receiving circuit. This is because it is normally performed by 42B.

In the second embodiment, when the boundary reception signal line is connected to the reception circuit 42A, the MCU 5 controls the multiplexer 43B to connect the boundary reception signal line to the specific terminal TSc of the multiplexer 43A, and also controls the multiplexer 43B. The multiplexer 43A is controlled to connect a specific terminal TSc to the receiving circuit 42A.
As a result, even when the boundary reception signal line is connected to one of the multiplexers 43B, the signal path can be switched to a state in which the reception circuit 42A can sense. This is suitable when there is a situation in which it is difficult to form a branch wiring between the touch panel 2 and the multiplexer 43 as the wiring of the boundary reception signal line.

Claims (5)

A touch panel drive device that sequentially scans a touch panel to select a pair of adjacent transmission signal lines and a pair of adjacent reception signal lines.
A plurality of received signal lines which are a part of all received signal lines on the touch panel and are arranged in an adjacent state are designated as a first received signal line group.
It is a part of all the received signal lines in the touch panel, and is a plurality of received signal lines arranged in an adjacent state, and only one received signal line is included in the first received signal line group. When a plurality of received signal lines to be different are set as the second received signal line group,
A first receiving circuit configured to be capable of performing sensing scanning on each received signal line of the first received signal line group, and a first receiving circuit.
A second receiving circuit, which is an IC chip different from the first receiving circuit and is configured to be capable of performing sensing scanning on each received signal line of the second received signal line group.
The reception signal by the boundary reception signal line included in both the first reception signal line group and the second reception signal line group is supplied to the first reception circuit and the second reception circuit at different timings. A touch panel drive device equipped with a control unit that controls switching of signal paths so as to be performed. A pair of received signal lines are sequentially selected and connected by a multiplexer in the process of scanning to each of the first receiving circuit and the second receiving circuit.
The touch panel drive device according to claim 1, wherein the control unit performs the switching control by setting terminals for the multiplexer. A first multiplexer that selectively connects each received signal line of the first received signal line group to the first received circuit, and
A second multiplexer that selectively connects each received signal line of the second received signal line group to the second received circuit, and
Equipped with
The control unit
When the boundary reception signal line is connected to the first reception circuit by the first multiplexer, the boundary reception signal line is disconnected from the second reception circuit by the second multiplexer.
When the boundary reception signal line is connected to the second receiving circuit by the second multiplexer, the boundary reception signal line is disconnected from the first reception circuit by the first multiplexer. The touch panel drive device according to claim 1 or 2. A first multiplexer that selectively connects a terminal to which each reception signal line of the first reception signal line group excluding the boundary reception signal line is connected and a specific terminal to the first reception circuit.
A second multiplexer that selectively connects the terminal to which each reception signal line of the second reception signal line group is connected to the second reception circuit, and
Equipped with
When the control unit connects the boundary reception signal line to the first reception circuit, the control unit may use the control unit.
The second multiplexer is controlled to connect the boundary signal line to the specific terminal of the first multiplexer, and the specific terminal is connected to the first receiving circuit of the first multiplexer. The touch panel driving device according to claim 1 or 2, wherein the touch panel driving device is controlled to be operated. Touch panel and
The touch panel has a touch panel driving device that sequentially performs scanning for selecting a pair of adjacent transmission signal lines and a pair of adjacent reception signal lines.
The touch panel drive device is
A plurality of received signal lines which are a part of all received signal lines on the touch panel and are arranged in an adjacent state are designated as a first received signal line group.
It is a part of all the received signal lines in the touch panel, and is a plurality of received signal lines arranged in an adjacent state, and only one received signal line is included in the first received signal line group. When a plurality of received signal lines to be different are set as the second received signal line group,
A first receiving circuit configured to be capable of performing sensing scanning on each received signal line of the first received signal line group, and a first receiving circuit.
A second receiving circuit, which is an IC chip different from the first receiving circuit and is configured to be capable of performing sensing scanning on each received signal line of the second received signal line group.
The reception signal by the boundary reception signal line included in both the first reception signal line group and the second reception signal line group is supplied to the first reception circuit and the second reception circuit at different timings. A touch panel device including a control unit that controls switching of signal paths so as to be performed.

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