Sensor controller, electronic apparatus, and control method for sensor controller

Abstract

To reduce power consumption without connecting elements such as switches to output signal lines.SOLUTION: A sensor controller includes: a plurality of transmission drivers that each have a first terminal and a second terminal, generate signal waveforms that transition between a first potential and a second potential, and output the signal waveforms to a corresponding detection electrode; and an intermediate potential supply unit that has a potential generation unit including a voltage source or a capacitive element separate from the transmission drivers, and supplies an intermediate potential between the first potential and the second potential to at least one of the first terminal and the second terminal by outputting voltage from the potential generation unit.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sensor controller, and more particularly to a sensor controller connected to a touch sensor, an electronic device, and a method for controlling the sensor controller. [Background technology]

[0002] Conventionally, in a circuit in which multiple transmission drivers are arranged in parallel, a technology (so-called adiabatic driving technology) has been known in which the output signal lines of the transmission drivers are shorted together by a control signal for a predetermined period of time, and the potential of the output signal lines is gradually transitioned from a high level to a low level via an intermediate potential that is between a high level and a low level, or from a low level to a high level via the intermediate potential, thereby reducing the power consumption of the circuit.

[0003] In this regard, Patent Document 1 discloses a tablet terminal including a plurality of sensor electrodes, an output signal line provided for each sensor electrode and connected to the sensor electrode, a switch provided for each output signal line, one end of which is connected to the output signal line and the other end of which is connected to a short line, and a control signal line for controlling each switch.

[0004] Patent document 2 also discloses a processing system including a driver module having a transmitter electrode and an electronic storage device configured to drive the transmitter electrode from an intermediate potential between a first potential and a second potential to the second potential and to drive the transmitter electrode to the intermediate potential.

[0005] In Patent Documents 1 and 2, the tablet terminal controls each switch to short-circuit each output signal line or connect each output signal line to an electronic storage device for a certain period of time when the potential of each sensor electrode transitions from high level to low level or from low level to high level, and reduces power consumption by supplying charge from the output signal line whose potential is at a high level to the output signal line whose potential is at a low level via a short line or an electronic storage device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-091442 A [Patent Document 2] Patent No. 6156886 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the techniques described in Patent Documents 1 and 2, since a switch is connected to the output signal line, there is a possibility that the parasitic capacitance of the switch may affect the transmission signal.

[0008] The present invention has been made in consideration of these problems, and its purpose is to provide a sensor controller, an electronic device, and a control method for a sensor controller that can reduce power consumption without connecting elements such as switches to an output signal line. [Means for solving the problem]

[0009] In order to solve the above problems, a sensor controller according to a first aspect of the present invention is connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, has a positive power supply terminal and a negative power supply terminal, and generates a signal waveform that transitions between a first potential that is supplied to the negative power supply terminal and is higher than the first potential and a second potential that is supplied to the positive power supply terminal, and outputs the signal waveform as a transmission signal to the corresponding detection electrode; and an intermediate potential supply unit that has a potential generation unit that includes a voltage source or a capacitive element separate from the transmission driver, and supplies an intermediate potential between the first potential and the second potential to at least one of the positive power supply terminal and the negative power supply terminal by outputting a voltage from the potential generation unit at a first timing when the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential.

[0010] In addition, a second sensor controller according to the present invention is connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, and includes a plurality of transmission drivers having a positive power supply terminal and a negative power supply terminal, generating a signal waveform that transitions between a first potential supplied to the negative power supply terminal and a second potential supplied to the positive power supply terminal that is a potential higher than the first potential, and outputting the signal waveform to the corresponding detection electrode as a transmission signal; and an intermediate potential supply unit that generates an intermediate potential between the first potential and the second potential, supplies the intermediate potential to at least one of the positive power supply terminal and the negative power supply terminal of at least one of the transmission drivers during a period from a time point at which the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential to a time point at which the potentials of the positive power supply terminal and the negative power supply terminal of the transmission driver reach the intermediate potential, and stops supplying the intermediate potential at the timing when the potential of at least one of the positive power supply terminal and the negative power supply terminal reaches the intermediate potential.

[0011] Moreover, an electronic device according to a third aspect of the present invention includes a touch sensor having a plurality of detection electrodes arranged in a planar shape; a plurality of transmission drivers connected to the touch sensor and having a negative power supply terminal to which a first potential is supplied and a positive power supply terminal to which a second potential higher than the first potential is supplied, the transmission drivers generating signal waveforms that transition between the first potential and the second potential and outputting the signal waveforms as transmission signals to the corresponding detection electrodes; and a sensor controller having a potential generating unit including a voltage source or a capacitive element separate from the transmission drivers, and an intermediate potential supply unit that supplies an intermediate potential between the first potential and the second potential to at least one of the positive power supply terminal and the negative power supply terminal by outputting a voltage from the potential generating unit at a first timing when the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential.

[0012] Moreover, an electronic device according to a fourth aspect of the present invention includes a touch sensor having a plurality of detection electrodes arranged in a planar shape; a plurality of transmission drivers connected to the touch sensor and having a negative power supply terminal to which a first potential is supplied and a positive power supply terminal to which a second potential higher than the first potential is supplied, the transmission drivers generating a signal waveform that transitions between the first potential and the second potential and outputting the signal waveform as a transmission signal to the corresponding detection electrode; and an intermediate potential supply unit that generates an intermediate potential between the first potential and the second potential and supplies the intermediate potential to at least one of the positive power supply terminal and the negative power supply terminal of at least one of the transmission drivers during a period from a time point at which the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential to a time point at which the potentials of the positive power supply terminal and the negative power supply terminal reach the intermediate potential, and stops supplying the intermediate potential at a timing when the potential of at least one of the positive power supply terminal and the negative power supply terminal reaches the intermediate potential.

[0013] A fifth control method of a sensor controller according to the present invention is a control method of a sensor controller connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, and includes: generating a signal waveform that transitions between a first potential and the second potential by a plurality of transmission drivers having a negative power supply terminal to which a first potential is supplied and a positive power supply terminal to which a second potential higher than the first potential is supplied; outputting the signal waveform generated by the transmission drivers as a transmission signal to the corresponding detection electrodes; outputting an intermediate potential between the first potential and the second potential from a potential generating unit including a voltage source or a capacitive element separate from the transmission drivers at a first timing at which the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential; and supplying the intermediate potential to at least one of the positive power supply terminal and the negative power supply terminal.

[0014] A sixth control method of a sensor controller according to the present invention is a control method of a sensor controller connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, the control method including: generating a signal waveform that transitions between a first potential and the second potential by a plurality of transmission drivers having a negative power supply terminal to which a first potential is supplied and a positive power supply terminal to which a second potential higher than the first potential is supplied; outputting the signal waveform generated by the transmission drivers as a transmission signal to the corresponding detection electrodes; generating an intermediate potential between the first potential and the second potential; supplying the intermediate potential to at least one of the positive power supply terminal and the negative power supply terminal of at least one of the transmission drivers during a period from a time point at which the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential to a time point at which the potentials of the positive power supply terminal and the negative power supply terminal of the transmission driver reach the intermediate potential; and stopping the supply of the intermediate potential at a timing when the potential of at least one of the positive power supply terminal and the negative power supply terminal reaches the intermediate potential. Effect of the Invention

[0015] According to the present invention, it is possible to reduce power consumption without connecting an element such as a switch to an output signal line. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating an example of an electronic device according to a first embodiment. [Diagram 2] 4 is a diagram illustrating a part of a circuit configuration of an output circuit and an example of a touch sensor. FIG. [Diagram 3] FIG. 2 is a diagram showing an example of a circuit configuration of an output circuit including an intermediate potential supply unit; [Figure 4] 4 is a timing chart showing an example of transition of potentials of each signal in an output circuit. [Figure 5A] FIG. 2 is a diagram illustrating a first example of a circuit configuration of a transmission driver. [Figure 5B] FIG. 13 is a diagram illustrating a second example of the circuit configuration of the transmission driver. [Figure 5C] FIG. 13 is a diagram illustrating a third example of a circuit configuration of a transmission driver. [Figure 5D] FIG. 13 is a diagram illustrating a fourth example of a circuit configuration of a transmission driver. [Figure 6] 10 is a timing chart showing an example of transition of potentials of signals in a transmission driver. [Figure 7] FIG. 11 is a diagram showing an example of a circuit configuration of an output circuit including an intermediate potential supply unit according to a second embodiment; [Figure 8] 10 is a timing chart showing transitions of potentials of signals in an output circuit according to a second embodiment; [Figure 9] FIG. 13 is a diagram showing an example of a circuit configuration of an output circuit including an intermediate potential supply unit according to a third embodiment; [Figure 10] 13 is a timing chart showing an example of transition of potentials of each signal in an output circuit according to a third embodiment. [Figure 11A] FIG. 11 is a diagram showing a first example of a circuit configuration of an output control circuit according to a third embodiment. [Figure 11B] FIG. 13 is a diagram illustrating a second example of the circuit configuration of an output control circuit according to a third embodiment. [Figure 12] FIG. 13 is a diagram showing an example of a circuit configuration of an output circuit including an intermediate potential supply unit according to a fourth embodiment; [Figure 13] 13 is a timing chart showing an example of transition of potentials of each signal in an output circuit according to the fourth embodiment. [Figure 14] FIG. 4 is a diagram showing an example of a circuit configuration of a voltage source in a potential generating unit. [Figure 15] 1 is a flowchart showing an example of a flow of a series of processes in an output circuit according to the first and second embodiments. [Figure 16] 13 is a flowchart showing an example of a flow of a series of operations of the output circuit according to the third and fourth embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components and steps in each drawing are denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0018] ---First embodiment--- First, the first embodiment will be described.

[0019] <Circuit configuration> 1 is a diagram showing an example of an electronic device 1 according to a first embodiment. The electronic device 1 is a computer owned by a user, and is configured, for example, as a tablet, a smartphone, or a personal computer. The user can write pictures or characters on the electronic device 1 by holding a stylus 2, which is a pen-shaped pointing device, and moving the pen tip while pressing it against a touch surface of the electronic device 1. The stylus 2 is, for example, an active electrostatic coupling type (AES) electronic pen, and is configured to be capable of bidirectional communication with the electronic device 1.

[0020] The electronic device 1 detects the position pointed to by the stylus 2 and performs various information processes according to the detection result. Specifically, the electronic device 1 transmits an uplink signal US to the stylus 2, detects the position pointed to by the stylus 2 according to the reception result of a downlink signal DS from the stylus 2, and performs processes such as generating digital ink and displaying a pointer. The electronic device 1 includes a sensor controller 10 and a touch sensor 20 in addition to a host processor, a memory, and a communication module (none of which are shown).

[0021] The touch sensor 20 is a capacitance type sensor having a plurality of detection electrodes arranged in a planar shape. The touch sensor 20 includes, for example, a plurality of X-line electrodes (hereinafter referred to as "linear electrodes 21") for detecting the position of the X-axis of a sensor coordinate system, and a plurality of Y-line electrodes (hereinafter referred to as "linear electrodes 22") for detecting the position of the Y-axis. The linear electrodes 21 and 22 may be made of a transparent conductive material including ITO (Indium Tin Oxide), or may be made of a wire mesh sensor. The touch sensor 20 may be a self-capacitance type sensor in which block-shaped electrodes are arranged in a two-dimensional lattice shape, instead of the mutual capacitance type sensor described above.

[0022] The sensor controller 10 includes an MCU (Micro Controller Unit) 11, a control circuit 12, a transmission circuit 13, a reception circuit 14, an output circuit 15, a detection circuit 16, and selection circuits 17 and 18.

[0023] The output circuit 15 is a circuit that selects one of the plurality of linear electrodes 22 or a plurality of adjacent electrodes based on an instruction from the control circuit 12, amplifies an input signal transmitted from the control circuit 12 to a predetermined voltage, and outputs the output signal to the linear electrode 22. The detection circuit 16 is a circuit that selects one of the plurality of linear electrodes 21 or a plurality of adjacent electrodes based on an instruction from the control circuit 12.

[0024] The selection circuit 17 is, for example, a multiplexer, and is a circuit for switching whether the linear electrode 22 selected by the output circuit 15 is used for reception or transmission. When the selection signal SELY output from the control circuit 12 is in a low state "0", the selection circuit 17 connects the linear electrode 22 selected by the output circuit 15 to the reception circuit 14 via the selection circuit 18. On the other hand, when the selection signal SELY is in a high state "1", the selection circuit 17 supplies the input signal input from the control circuit 12 via the transmission circuit 13 to the linear electrode 22 selected by the output circuit 15.

[0025] The selection circuit 18 is, for example, a multiplexer, and selects either a signal input via the selection circuit 17 from the linear electrode 22 selected by the output circuit 15, or a signal input from the linear electrode 21 selected by the detection circuit 16, and outputs the selected signal to the receiving circuit 14. On the other hand, when the selection signal SELX output from the control circuit 12 is in a low state, the selection circuit 18 connects the linear electrode 22 selected by the output circuit 15 to the receiving circuit 14. On the other hand, when the selection signal SELX is in a high state, the selection circuit 18 connects the linear electrode 22 selected by the output circuit 15 to the receiving circuit 14 via the selection circuit 17.

[0026] The electronic device 1 has the following four modes, and the control circuit 12 controls each circuit in the sensor controller 10 while switching between these modes in the order shown below. Each mode will be described in detail below.

[0027] The first mode is a mode for detecting the position of a finger. In this mode, the control circuit 12 sets the selection signal SELY to a high state and the selection signal SELX to a low state. That is, a transmission signal output from the control circuit 12 via the transmission circuit 13 and the output circuit 15 is supplied to the linear electrode 22 selected by the output circuit 15, and a touch detection signal is transmitted from the touch sensor 20. In addition, the linear electrode 21 selected by the detection circuit 16 is connected to the reception circuit 14. With this configuration, the MCU 11 reads a change in the detection signal caused by a finger touching the sensor surface and calculates the coordinate position of the finger.

[0028] The second mode is a mode in which an uplink signal US is transmitted to the stylus 2. In this case, the control circuit 12 sets the selection signal SELY to a high state, whereby a transmission signal output from the control circuit 12 via the transmission circuit 13 and the output circuit 15 is supplied to the linear electrode 22 selected by the output circuit 15, and an uplink signal US is transmitted from the touch sensor 20. At this time, the output circuit 15 may select an electrode of the linear electrode 22 in the vicinity of the electrode pointed to by the stylus 2 and transmit the uplink signal US, or the output circuit 15 may simultaneously select all electrodes of the linear electrode 22 and transmit the trigger signal US_trg.

[0029] The third mode is a mode in which the position of the stylus 2 is detected by detecting the position signal DS_pos transmitted by the stylus 2. In this case, the control circuit 12 sets the selection signal SELY to a low state, so that the linear electrode 22 selected by the output circuit 15 is connected to the receiving circuit 14 via the selection circuit 17. When determining the X-axis coordinate of the stylus 2, the control circuit 12 sets the selection signal SELX to a low state and connects the linear electrode 21 selected by the detection circuit 16 to the receiving circuit 14. In this state, the MCU 11 reads the data output from the receiving circuit 14 as a signal level value while sequentially selecting the linear electrodes 21 selected by the detection circuit 16 one by one from a plurality of linear electrodes 21, for example, five linear electrodes 21, with the linear electrode 21 closest to the pointing position of the stylus 2 at the center. The MCU 11 calculates the X-axis coordinate of the stylus 2 from the signal level distribution for the selected linear electrode 21. Furthermore, when determining the Y-axis coordinate of the stylus 2, the control circuit 12 sets the selection signal SELX to a high state, and connects the linear electrode 22 selected by the output circuit 15 to the receiving circuit 14. In this state, the MCU 11 reads the data output from the receiving circuit 14 as signal level values ​​while sequentially selecting, one by one, the linear electrodes 22 selected by the output circuit 15, from among a plurality of linear electrodes 22 (for example, five linear electrodes 22) centered on the linear electrode 22 closest to the pointing position of the stylus 2. The MCU 11 calculates the Y-axis coordinate of the stylus 2 from the signal level distribution for the selected linear electrodes 22.

[0030] The fourth mode is a mode for receiving the data signal DS_res transmitted by the stylus 2. When receiving the data signal DS_res, either the linear electrode 21 or the linear electrode 22 may be used, but here, a case where the data signal DS_res is received using the linear electrode 21 will be described. The control circuit 12 connects the linear electrode 21 selected by the detection circuit 16 to the reception circuit 14 by setting the selection signal SELX to a low state. Also, the detection circuit 16 operates the control circuit 12 so that multiple linear electrodes 21, for example, three linear electrodes 21, centered on the linear electrode 21 closest to the pointing position of the stylus 2, are simultaneously selected. In this state, the MCU 11 periodically reads the output from the reception circuit 14. When receiving the data signal DS_res using the linear electrode 22, the selection signal SELY may be set to a low state and the selection signal SELX may be set to a high state.

[0031] The above is the operation of the control circuit 12 in each mode. As can be understood from the above description, the electronic device 1 is configured to transmit and receive signals using the same touch sensor 20 for both transmission and reception. Other configurations within the electronic device 1 shown in FIG. 1 will now be described.

[0032] The MCU 11 is a microprocessor having an internal ROM (Read Only Memory) and RAM (Random Access Memory) and operating based on a predetermined program. The MCU 11 controls the control circuit 12 so as to output each signal output from the control circuit 12 as described above, and also reads and processes the digital data output by the receiving circuit 14.

[0033] The control circuit 12 is a logic circuit for accurately outputting each signal at a specified timing based on instructions from the MCU 11 .

[0034] The above has described the configuration and operation of the electronic device 1. Next, a detailed description will be given of the configuration of the circuit that functions when the output circuit 15 transmits a signal to the linear electrode 22. Fig. 2 is a diagram showing a part of the circuit configuration of the output circuit 15 according to this embodiment and an example of the touch sensor 20.

[0035] As shown in FIG. 2, the output circuit 15 includes a driver selection circuit 151, a plurality of transmission drivers 152, and an intermediate potential supply unit 153.

[0036] The driver selection circuit 151 selects some of the multiple transmission drivers 152 that transmit signals to the linear electrodes 22 in accordance with instructions from the control circuit 12, and outputs each input signal IN to the corresponding transmission driver 152, using the data signals transmitted from the transmission circuit 13 as multiple input signals IN.

[0037] One transmission driver 152 is provided for each linear electrode 22. The transmission driver 152 amplifies an input signal IN input from the driver selection circuit 151 to a potential difference at which a signal can be transmitted from the linear electrode 22, and transmits the amplified signal as a transmission signal OUT to the corresponding linear electrode 22 via an output signal line Wout. Here, the potential difference at which a signal can be transmitted from the linear electrode 22 is a potential difference of 5V or more, for example, about 9V, where a low level is, for example, 0V (first potential) and a high level is, for example, about 9V, where a high level is, for example, about 5V or more (second potential). The transmission driver 152 also has a positive power supply terminal to which a positive power supply potential (high level) is supplied, and a negative power supply terminal to which a negative power supply potential (low level) is supplied.

[0038] The intermediate potential supplying unit 153 generates an intermediate potential that is a potential between a high level and a low level. Here, the intermediate potential is, for example, a potential obtained by adding the values ​​of the high level and the low level and dividing the result by two. The intermediate potential supplying unit 153 supplies the generated intermediate potential to the positive power supply terminal of the transmission driver 152 selected by the driver selection circuit 151 at the timing when the potential of the signal waveform generated by the transmission driver 152 transitions from the low level to the high level. The intermediate potential supplying unit 153 supplies the generated intermediate potential to the negative power supply terminal of the transmission driver 152 selected by the driver selection circuit 151 at the timing when the potential of the signal waveform generated by the transmission driver 152 transitions from the high level to the low level. The intermediate potential supplying unit 153 stops supplying the intermediate potential to the transmission driver 152 at the timing when the potential of the signal waveform generated by the transmission driver 152, which is the supply target of the intermediate potential, reaches the intermediate potential.

[0039] The above describes the configuration of the output circuit 15. Next, a detailed description will be given of the circuit configuration of the intermediate potential supplying section 153. Fig. 3 is a diagram showing an example of the circuit configuration of the output circuit 15 including the intermediate potential supplying section 153A according to this embodiment.

[0040] As shown in Fig. 3, the output circuit 15A includes a driver selection circuit 151, a plurality of transmission drivers 152A, and an intermediate potential supply unit 153A. In this figure, the driver selection circuit 151 selects n+1 transmission drivers 152A, where n is a positive integer. The linear electrode 22 has a capacitance element Cout as a load capacitance. The capacitance of the capacitance element Cout is, for example, about 1200 pF.

[0041] As described above, the driver selection circuit 151 selects n+1 transmission drivers 152A and transmits an input signal IN to the selected transmission drivers 152A. Here, the input signal IN0 is input to the 0th transmission driver 152A. The input signal IN1 is input to the 1st transmission driver 152A, the input signal INn-1 is input to the nth transmission driver 152A, and the input signal INn is input to the n+1th transmission driver 152A.

[0042] The transmission driver 152A is a driver in which an output control function is added to the above-mentioned transmission driver 152. The transmission driver 152A sets the mode to the output mode or the stop mode according to the output control signal EN output from the control circuit 12. Meanwhile, in the output mode, the transmission driver 152A amplifies the input signal IN to a potential difference at which the signal can be transmitted from the linear electrode 22, and transmits the amplified signal as the transmission signal OUT to the corresponding linear electrode 22 via the output signal line Wout. Meanwhile, in the stop mode, the transmission driver 152A sets the output state to a high impedance state "Hi-Z" and stops transmission of the transmission signal OUT.

[0043] The intermediate potential supply unit 153A includes a potential generation unit 154A, a plurality of short-circuit control elements SWU, a plurality of short-circuit control elements SWD, a short-circuit control element SWr, a reset voltage source Vrst, and a short-circuit signal line Ws.

[0044] The potential generating unit 154A includes, for example, a voltage source Vmid and a capacitance element Cext. The voltage source Vmid is, for example, a voltage source that generates an intermediate potential. The potential generating unit 154A generates an intermediate potential, for example, 4.5V, and applies the generated intermediate potential to the short-circuit signal line Ws. The capacitance element Cext is, for example, a capacitor with a capacitance of about 1 uF, one end of which is connected to the short-circuit signal line Ws and the other end of which is connected to the reference line GND. The capacitance element Cext charges or discharges an electric charge according to the potential supplied to the short-circuit signal line Ws, and stabilizes the potential of the short-circuit signal line Ws. Note that, in this embodiment, the potential generating unit 154A includes the voltage source Vmid and the capacitance element Cext, but may be configured with only one of the voltage source Vmid and the capacitance element Cext.

[0045] The reset voltage source Vrst is a voltage source that generates an initial potential (e.g., 4.5 V) and supplies the initial potential generated when the short-circuit control element SWr is short-circuited to the short-circuit signal line Ws. One end of the reset voltage source Vrst is connected to the other end of the short-circuit control element SWr, and the other end is connected to the reference line GND.

[0046] The short-circuit control elements SWU, SWD, and SWr are, for example, switch elements or transistors. The short-circuit control elements SWU, SWD, and SWr short-circuit or open both ends according to the input signal. Specifically, on the one hand, the short-circuit control elements SWU, SWD, and SWr short-circuit both ends when the input signal is in a high state. On the other hand, the short-circuit control elements SWU, SWD, and SWr open both ends when the input signal is in a low state. In addition, the short-circuit control elements SWU and SWD are provided for each transmission driver 152A.

[0047] The short-circuit control element SWr has one end connected to the short-circuit signal line Ws and the other end connected to one end of the reset voltage source Vrst. The short-circuit control element SWr shorts or opens both ends in response to a reset signal RST output from the control circuit 12.

[0048] One end of the short-circuit control element SWU is connected to the positive power supply terminal of the corresponding transmission driver 152A, and the other end is connected to the short-circuit signal line Ws. The short-circuit control element SWU shorts or opens both ends in accordance with a control signal CTU output from the control circuit 12.

[0049] One end of the short-circuit control element SWD is connected to the negative power supply terminal of the corresponding transmission driver 152A, and the other end is connected to the short-circuit signal line Ws. The short-circuit control element SWD shorts or opens both ends in accordance with a control signal CTD output from the control circuit 12.

[0050] In the output circuit 15A configured as above, the control circuit 12 controls the state of the transmission driver 152A to a high impedance state and controls the short-circuit control element SWU to a short-circuit state at the timing when the state of any of the input signals IN0 to INn transitions from a low state to a high state. Also, the control circuit 12 controls the state of the transmission driver 152A to a high impedance state and controls the short-circuit control element SWD to a short-circuit state at the timing when the state of any of the input signals IN0 to INn transitions from a high state to a low state. As a result, the positive power supply terminal and the short-circuit signal line Ws of the transmission driver 152A corresponding to the input signal IN whose state transitions from a low state to a high state are short-circuited, and the negative power supply terminal and the short-circuit signal line Ws of the transmission driver 152A corresponding to the input signal IN whose state transitions from a high state to a low state are short-circuited, so that a potential is supplied from the output signal line Wout whose potential is at a high level to the output signal line Wout whose potential is at a low level and the capacitance element Cext through the short-circuit signal line Ws. Further, a potential is supplied from the voltage source Vmid and the capacitive element Cext via the short-circuit signal line Ws to the output signal line Wout, which is at a low level.

[0051] Next, when the potentials of the positive power supply terminal, the negative power supply terminal, the short-circuit signal line Ws, and one end of the capacitance element Cext of each transmission driver 152A reach the intermediate potential, the control circuit 12 controls the state of the transmission driver 152A to the output state and controls the short-circuit control elements SWU and SWD to the open state. As a result, the potential of each output signal line Wout transitions to a high level or a low level by the corresponding transmission driver 152A, and the transmission signals OUT0, OUT1, OUTn-1, and OUTn are transmitted via the linear electrodes 22.

[0052] The configuration of the intermediate potential supply unit 153A has been described above. Next, the circuit configuration of the transmission driver 152 will be described in detail. Fig. 5A is a diagram showing an example of the circuit configuration of the transmission driver 152A according to this embodiment. As shown in Fig. 5A, the transmission driver 152A includes, for example, logical negation circuits INV1 and INV2, transistors TR1, TR2, TR3 and TR4, a power supply line VDD, and a reference line GND.

[0053] The logical negation circuits INV1 and INV2 are inverter circuits including transistors, for example. The logical negation circuit INV1 performs a logical negation operation on the input signal IN input from the driver selection circuit 151, and outputs the signal obtained by the operation to the gate terminals of the transistors TR2 and TR3. The logical negation circuit INV2 performs a logical negation operation on the output control signal EN input from the control circuit 12, and outputs the signal obtained by the operation to the gate terminal of the transistor TR1.

[0054] The transistors TR1 and TR2 are, for example, P-type MOS (Metal Oxide Semiconductor) transistors. The transistors TR1 and TR2 supply the potential supplied to the source terminal to the drain terminal or stop the supply according to a signal input to the gate terminal. Specifically, when the state of the signal input to the gate terminal is low, the transistors TR1 and TR2 supply the potential supplied to the source terminal to the drain terminal, while stopping the supply when the state of the signal input to the gate terminal is high.

[0055] The transistor TR1 has a gate terminal connected to the output terminal of the logical NOT circuit INV2, a source terminal connected to the power supply line VDD, and a drain terminal connected to the positive power supply terminal of the transmission driver 152A.

[0056] The transistor TR2 has a gate terminal connected to the output terminal of the logical NOT circuit INV1, a source terminal connected to the positive power supply terminal of the transmission driver 152A, and a drain terminal connected to the drain terminal of the transistor TR3 and the output signal line Wout.

[0057] The transistors TR3 and TR4 are, for example, N-type MOS (Metal Oxide Semiconductor) transistors. The transistors TR3 and TR4 extract or stop the extraction of electric charge from the drain terminal to the source terminal according to a signal input to the gate terminal. Specifically, when the state of the signal input to the gate terminal is high, the transistors TR3 and TR4 extract electric charge from the drain terminal to the source terminal, while when the state of the signal input to the gate terminal is low, the transistors TR3 and TR4 stop the extraction.

[0058] The transistor TR3 has a gate terminal connected to the output terminal of the logical NOT circuit INV1, a source terminal connected to the negative power supply terminal of the transmission driver 152A, and a drain terminal connected to the drain terminal of the transistor TR2 and the output signal line Wout.

[0059] The transistor TR4 has a gate terminal connected to the control circuit 12, a source terminal connected to the reference line GND, and a drain terminal connected to the negative power supply terminal of the transmission driver 152A.

[0060] The power supply line VDD supplies a high-level potential to the transmission driver 152A, which is supplied from a voltage source (not shown). Here, the high-level potential is a potential of 5V or more, for example, about 9V. The reference line GND supplies a low-level potential to the transmission driver 152A. Here, the low-level potential is, for example, a potential of 0V.

[0061] The transmission driver 152A configured as described above, in the output mode where the output control signal EN is in the low state, amplifies the input signal IN to a potential difference that allows the signal to be transmitted from the linear electrode 22, and transmits the amplified signal as the transmission signal OUT to the output signal line Wout. On the other hand, in the stop mode where the output control signal EN is in the high state, the transmission driver 152A sets the output state to the high impedance state "Hi-Z" and stops transmission of the transmission signal OUT.

[0062] 5B is a diagram showing another example of the circuit configuration of the transmission driver 152 according to the present embodiment. As shown in FIG. 5B, the transmission driver 152B includes, for example, current sources I0 and I1 in addition to the configuration of the transmission driver 152A described above. In the description of the circuit configuration of the transmission driver 152B, the description of the same configuration as that of the transmission driver 152A will be omitted.

[0063] The current sources I0 and I1 are, for example, current mirror circuits including MOS transistors. The current source I0 limits the current flowing from the power supply line VDD to the source terminal of the transistor TR1 to a constant current value. The current source I1 limits the current flowing from the source terminal of the transistor TR4 to the reference line GND to a constant current value.

[0064] The transmission driver 152B configured as above limits the current flowing from the power supply line VDD to the transmission driver 152B and the current flowing from the transmission driver 152B to the reference line GND to constant current values, thereby making the transition of the potential of the transmission signal OUT more gradual than that of the transmission driver 152A. As a result, the EMI characteristics of the transmission driver 152B are improved compared to that of the transmission driver 152A by reducing the high-frequency components of the transmission driver 152B.

[0065] 5C is a diagram showing another example of the circuit configuration of the transmission driver 152 according to the present embodiment. As shown in FIG. 5C, the transmission driver 152C includes, in addition to the configuration of the transmission driver 152A described above, for example, a logical sum circuit OR, a logical product circuit AND, and delay circuits DL0 and DL1. In the description of the circuit configuration of the transmission driver 152C, the description of the same configuration as that of the transmission driver 152A will be omitted.

[0066] The logical sum circuit OR is configured to include, for example, MOS transistors, and performs a logical sum operation on the output signal of the logical negation circuit INV1 and the trigger signal TGn output from the delay circuit DL1, and outputs the result of the operation to the delay circuit DL0.

[0067] The AND circuit AND is configured to include, for example, MOS transistors, and performs a logical AND operation on the output signal of the logical negation circuit INV1 and the trigger signal TGp output from the delay circuit DL0, and outputs the result of this operation to the delay circuit DL1.

[0068] The delay circuits DL0 and DL1 are buffer circuits including, for example, MOS transistors. The delay circuit DL0 delays the output signal of the logical sum circuit OR by a delay time td, and outputs the delayed signal as a trigger signal TGp to the gate terminal of the transistor TR2 and the logical product circuit AND. The delay circuit DL1 delays the output signal of the logical product circuit AND by a delay time td, and outputs the delayed signal as a trigger signal TGn to the gate terminal of the transistor TR3 and the logical sum circuit OR.

[0069] In the transmission driver 152C configured as described above, the logical sum circuit OR, the logical product circuit AND, the drain terminal and source terminal of transistor TR2, and the drain terminal and source terminal of transistor TR3 are never simultaneously in a conductive state, thereby preventing the occurrence of a through current from the power supply line VDD through transistors TR1 to TR4 to the reference line GND.

[0070] 6 is a timing chart showing the transition of the potential of each signal in the transmission driver 152C according to this embodiment. Although not shown, the state of the output control signal EN is assumed to be high level at any time.

[0071] 6, at time t60, the driver selection circuit 151 transitions the state of the input signal IN from a low state to a high state. At time t60, the logical negation circuit INV1 performs a logical negation operation on the input signal IN (high state), and outputs the signal that is in a low state as a result of the operation to the logical sum circuit OR and the logical product circuit AND. At time t60, the logical product circuit AND performs a logical product operation on the trigger signal TGp (high state) and the signal (low state) output from the logical negation circuit INV1, and outputs the signal that is in a low state as a result of the operation to the delay circuit DL1.

[0072] At time t60, the delay circuit DL1 receives the signal that has become low from the AND circuit AND, and delays the signal by delay time td. At time t61, which is the delay time td after time t60, the delay circuit DL1 outputs the delayed result as a trigger signal TGn to the gate terminal of transistor TR3 and to the OR circuit OR. At time t61, the transistor TR3 receives the trigger signal TGn in the low state, and makes the drain terminal and the source terminal non-conductive. As a result, the drain terminal and the source terminal of transistor TR2 and the drain terminal and the source terminal of transistor TR3 are both non-conductive, and the output signal line Wout is in a high impedance state.

[0073] At time t61, the logical sum circuit OR performs a logical sum operation on the trigger signal TGn (low state) and the signal (low state) output from the logical negation circuit INV1, and outputs the signal that has become low state as a result of the operation to the delay circuit DL0.

[0074] At time t61, the delay circuit DL0 receives the signal that has become low from the logical sum circuit OR and delays the signal by delay time td. At time t62, which is the delay time td after time t61, the delay circuit DL0 outputs the delayed result as a trigger signal TGp to the gate terminal of transistor TR2 and to the logical product circuit AND. At time t62, the transistor TR2 receives the trigger signal TGp in the low state and makes the drain terminal and source terminal conductive. As a result, a high-level potential is supplied from the power supply line VDD to the output signal line Wout via the transistors TR1 and TR2, and the potential of the transmission signal OUT transitions to a high level.

[0075] At time t63, the driver selection circuit 151 transitions the state of the input signal IN from a high state to a low state. At time t63, the logical negation circuit INV1 performs a logical negation operation on the input signal IN (low state), and outputs the signal that is in a high state as a result of the operation to the logical sum circuit OR and the logical product circuit AND. At time t63, the logical sum circuit OR performs a logical sum operation on the trigger signal TGn (low state) and the signal (high state) output from the logical negation circuit INV1, and outputs the signal that is in a high state as a result of the operation to the delay circuit DL0.

[0076] At time t63, the delay circuit DL0 receives the high-state signal from the logical sum circuit OR and delays the signal by delay time td. At time t64, which is the delay time td after time t63, the delay circuit DL0 outputs the delayed result as a trigger signal TGp to the gate terminal of transistor TR2 and to the logical product circuit AND. At time t63, the transistor TR2 receives the high-state trigger signal TGp and makes the drain terminal and source terminal non-conductive. As a result, the drain terminal and source terminal of transistor TR2 and the drain terminal and source terminal of transistor TR3 are both non-conductive, and the output signal line Wout is in a high impedance state.

[0077] At time t64, the AND circuit AND performs a logical AND operation on the trigger signal TGp (high state) and the signal (high state) output from the logical NOT circuit INV1, and outputs the signal that is in a high state as a result of the operation to the delay circuit DL1. At time t64, the delay circuit DL1 receives the signal that is in a high state from the AND circuit AND and delays the signal by a delay time td. At time t65, which is the delay time td after time t64, the delay circuit DL1 outputs the trigger signal TGn in a high state as the result of the delay to the gate terminal of the transistor TR3 and the OR circuit OR. At time t65, the transistor TR3 receives the trigger signal TGn in a high state and makes the drain terminal and the source terminal conductive. As a result, charges are drawn from the output signal line Wout to the reference line GND via the transistors TR1 and TR2, and the potential of the transmission signal OUT transitions to a low level.

[0078] 5D is a diagram showing another example of the circuit configuration of the transmit driver 152 according to the first embodiment of the present invention. As shown in FIG. 5D, the transmit driver 152D has a configuration in which the configuration of the transmit driver 152C is added to the configuration of the transmit driver 152B described above. Therefore, the description of the circuit configuration of the transmit driver 152D will be omitted.

[0079] As shown in FIG. 5D, the transmission driver 152D is configured by combining the configurations of the transmission drivers 152B and 152C, and therefore the EMI characteristics are improved compared to the transmission driver 152A by reducing high-frequency components, and the occurrence of a through current from the power supply line VDD through the transistors TR1 to TR4 to the reference line GND can be prevented.

[0080] <Flow of a series of operations related to the output circuit> The above describes the configuration of the transmission driver 152. Next, a detailed description will be given of the transition of potentials of each signal in the output circuit 15A. Fig. 4 is a timing chart showing the transition of potentials of each signal in the output circuit 15A according to this embodiment.

[0081] At time t40, the control circuit 12 sets the reset signal RST to a low state, thereby opening both ends of the short-circuit control element SWr, thereby stopping the supply of the initial potential from the reset voltage source Vrst to the short-circuit signal line Ws.

[0082] At time t41, the driver selection circuit 151 transitions the states of the input signals IN0 and INn-1 from a low state to a high state, while transitioning the states of the input signals IN1 and INn from a high state to a low state, and inputs the input signals IN0, IN1, INn-1, and INn to the corresponding transmitting drivers 152A.

[0083] At time t41, the control circuit 12 changes the state of the output control signal EN from high to low, and sets the mode of each transmission driver 152A to the stop mode. Also, at time t41, the control circuit 12 changes the state of the control signals CTU0, CTUn-1, CTD1, and CTDn from low to high, and outputs the control signals CTU0, CTUn-1, CTD1, and CTDn to the corresponding short-circuit control elements SWU or SWD, thereby shorting both ends of each short-circuit control element SWU and SWD. As a result, at time t41, each output signal line Wout is shorted via each short-circuit control element SWU and SWD whose both ends are shorted. At time t41, charges are supplied from the output signal line Wout whose potential is high and the potential generating unit 154A to the output signal line Wout whose potential is low, so that the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn become intermediate potentials.

[0084] At time t42, the control circuit 12 changes the state of the output control signal EN from a low state to a high state, and sets the mode of each transmission driver 152A to the output mode. Also, at time t42, the control circuit 12 changes the state of the control signals CTU0, CTUn-1, CTD1, and CTDn from a high state to a low state, and outputs the control signals CTU0, CTUn-1, CTD1, and CTDn to each short-circuit control element SWU or SWD, thereby opening both ends of each short-circuit control element SWU or SWD. As a result, at time t42, the short-circuit state between each output signal line Wout is released. At time t42, the potentials of the transmission signals OUT0 and OUTn-1 change from an intermediate potential to a high level by supplying charges from the corresponding transmission driver 152A, while the potentials of the transmission signals OUT1 and OUTn change from an intermediate potential to a low level by drawing charges from the corresponding transmission driver 152A.

[0085] At time t43, the control circuit 12 changes the state of the output control signal EN from high to low, and sets the mode of each transmission driver 152A to the stop mode. Also at time t43, the control circuit 12 changes the state of the control signals CTD0, CTDn-1, CTU1, and CTUn from low to high, and outputs the control signals CTD0, CTDn-1, CTU1, and CTUn to the corresponding short-circuit control elements SWU or SWD, thereby opening both ends of each short-circuit control element SWU and SWD. As a result, at time t43, the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn become intermediate potentials, similar to time t41.

[0086] At time t44, the control circuit 12 changes the state of the output control signal EN from a low state to a high state, and sets the mode of each transmission driver 152A to the output mode. Also, at time t44, the control circuit 12 changes the state of the control signals CTD0, CTDn-1, CTU1, and CTUn from a high state to a low state, and outputs the control signals CTD0, CTDn-1, CTU1, and CTUn to the corresponding short-circuit control elements SWU or SWD, thereby opening both ends of each short-circuit control element SWU and SWD. As a result, at time t44, the short-circuit state between each output signal line Wout is released. At time t44, the potentials of the transmission signals OUT0 and OUTn-1 change from an intermediate potential to a low level by supplying charges from the corresponding transmission driver 152A, while the potentials of the transmission signals OUT1 and OUTn change from an intermediate potential to a high level by drawing charges from the corresponding transmission driver 152A.

[0087] The transition of the potential of each signal in the output circuit 15A has been described above. Next, the flow of a series of processes in the output circuit 15A will be described in detail. Fig. 15 is a flowchart showing the flow of a series of processes in the output circuit 15A according to the first embodiment.

[0088] (Step SP20) The transmission driver 152A amplifies the input signal IN input from the driver selection circuit 151 to a potential difference at which the signal can be transmitted from the linear electrode 22, and transmits the amplified signal as a transmission signal OUT to the corresponding output signal line Wout. Then, the process proceeds to step SP12.

[0089] (Step SP22) The control circuit 12 judges whether the signal waveform of the transmission signal OUT rises from a low level to a high level. If the judgement is affirmative, the process proceeds to step SP24. If the judgement is negative, the process proceeds to step SP32.

[0090] (Step SP24) The control circuit 12 sets the mode of the transmission driver 152A to the stop mode, which puts the output of the transmission driver 152A into a high impedance state. Then, the process proceeds to step SP26.

[0091] (Step SP26) The control circuit 12 controls each short circuit control element SWU so that both ends are short circuited. As a result, each output signal line Wout is short circuited via the short circuit signal line Ws, and a potential is supplied from the potential generating unit 154A and the output signal line Wout whose potential is at a high level to the output signal line Wout whose potential is at a low level via the short circuit signal line Ws. The potentials of the short circuit signal line Ws and each output signal line Wout become intermediate potentials. Then, the process proceeds to the process of step SP28. Note that, as described in the second embodiment to be described later, when there are multiple short circuit signal lines Ws, the control circuit 12 determines which short circuit signal line Ws each output signal line Wout is to be connected to, and controls the short circuit control element SWU corresponding to the determined short circuit signal line Ws to be short circuited.

[0092] (Step SP28) The control circuit 12 controls each short circuit control element SWU so as to open both ends thereof, thereby releasing the short circuit between the output signal lines Wout, and the process proceeds to step SP30.

[0093] (Step SP30) The control circuit 12 sets the mode of the transmission driver 152A to the output mode. This causes the transmission driver 152A to supply a high level to the output signal line Wout. The potential of the transmission signal OUT transitions from the intermediate potential to the high level in accordance with the potential of the output signal line Wout.

[0094] (Step SP32) The control circuit 12 judges whether the signal waveform of the transmission signal OUT falls from a high level to a low level. On the other hand, if the judgment is positive, the process proceeds to step SP34. On the other hand, if the judgment is negative, the process ends the series of processes in FIG. 15.

[0095] (Step SP34) The control circuit 12 sets the mode of the transmission driver 152A to the stop mode, which puts the output of the transmission driver 152A into a high impedance state. Then, the process proceeds to step SP36.

[0096] (Step SP36) The control circuit 12 controls each short circuit control element SWD so that both ends are short circuited. As a result, each output signal line Wout is short circuited via the short circuit signal line Ws, and a potential is supplied from the potential generating unit 154A and the output signal line Wout whose potential is at a high level to the output signal line Wout whose potential is at a low level via the short circuit signal line Ws. The potentials of the short circuit signal line Ws and each output signal line Wout become intermediate potentials. Then, the process proceeds to the process of step SP38. Note that, as described in the second embodiment described later, when there are multiple short circuit signal lines Ws, the control circuit 12 determines which short circuit signal line Ws each output signal line Wout is to be connected to, and controls the short circuit control element SWD corresponding to the determined short circuit signal line Ws to be short circuited.

[0097] (Step SP38) The control circuit 12 controls each short circuit control element SWD so as to open both ends thereof, thereby releasing the short circuit between the output signal lines Wout, and the process proceeds to step SP40.

[0098] (Step SP40) The control circuit 12 sets the mode of the transmission driver 152A to the output mode. As a result, a low level is supplied from the transmission driver 152A to the output signal line Wout. The potential of the transmission signal OUT transitions from the intermediate potential to the low level in accordance with the potential of the output signal line Wout.

[0099] <Effects> As described above, in this embodiment, the sensor controller 10 is connected to the touch sensor 20 in which the linear electrodes 21 and 22 are arranged in a planar shape. The sensor controller 10 includes a plurality of transmission drivers 152A having a positive power supply terminal and a negative power supply terminal, generating a signal waveform that transitions between a first potential (low level) supplied to the negative power supply terminal and a second potential (high level) that is supplied to the positive power supply terminal and is higher than the first potential, and outputting the signal waveform as a transmission signal to a corresponding linear electrode 22; and an intermediate potential supply unit 153A having a potential generation unit 154A including a voltage source Vmid or a capacitive element Cext separate from the transmission driver 152A, supplying an intermediate potential between the first potential (low level) and the second potential (high level) to at least one of the positive power supply terminal and the negative power supply terminal by outputting a voltage from the potential generation unit 154A at a first timing (times t41, t43, t45, and t47) at which the potential of the signal waveform starts to transition from the first potential (low level) to the second potential (high level) or from the second potential (high level) to the first potential (low level).

[0100] According to this configuration, the sensor controller 10 can stably supply an intermediate potential to at least one of the positive power supply terminal and the negative power supply terminal of the transmission driver 152A at a required timing by outputting an intermediate potential from the intermediate potential supply unit 153A having a voltage source Vmid or a potential generation unit 154A having a capacitive element Cext separate from the transmission driver 152A to at least one of the positive power supply terminal and the negative power supply terminal of the transmission driver 152A. Therefore, according to the present invention, the sensor controller 10 can reduce power consumption compared to the conventional configuration without connecting an element such as a switch to the output signal line Wout.

[0101] In this embodiment, the output side of the potential generating unit 154A is connected to two or more of the multiple transmitting drivers 152A.

[0102] According to this configuration, the sensor controller 10 can suppress the shoot-through current and reduce power consumption compared to the conventional configuration.

[0103] In this embodiment, the sensor controller 10 includes a control circuit 12 that transmits control signals CTU and CTD. The transmission driver 152A has an output mode in which a transmission signal OUT is output, and a stop mode in which the supply of a second potential (high level) from the power supply line VDD to the positive power supply terminal and the supply of a first potential (low level) from the reference line GND to the negative power supply terminal are stopped, and the output state is set to a high impedance state. The control circuit 12 controls the transmission driver 152A to enter the stop mode at a first timing, and controls the transmission driver 152A to enter the output mode at a second timing (times t42, t44, t46, and t48) when a predetermined time has elapsed from the first timing.

[0104] According to this configuration, the sensor controller 10 can reduce power consumption by setting the output state of each transmission driver 152A to a high impedance state and providing a period during which an intermediate potential is stably supplied from the intermediate potential supply unit 153A to each transmission driver 152A.

[0105] In this embodiment, the intermediate potential supply unit 153A has a plurality of first short-circuit control elements SWU each having both ends shorted or opened according to a control signal CTU, one end connected to a corresponding positive power supply terminal, and the other end connected to the output side of the potential generation unit 154A, and a plurality of second short-circuit control elements SWD each having both ends shorted or opened according to a control signal CTD, one end connected to a corresponding negative power supply terminal, and the other end connected to the output side of the potential generation unit 154A. The control circuit 12 controls at least one of the first short-circuit control element SWU and the second short-circuit control element SWD to be short-circuited at a first timing, and controls at least one of the first short-circuit control element SWU and the second short-circuit control element SWD shorted at the first timing to be opened at a second timing.

[0106] According to this configuration, the sensor controller 10 can reduce power consumption compared to the conventional configuration without connecting an element such as a switch to the output signal line Wout.

[0107] In addition, in this embodiment, the control circuit 12 shorts the first short-circuit control element SWU at the timing during the first timing when the potential of the signal waveform starts to transition from the first potential (low level) to the second potential (high level), and shorts the second short-circuit control element SWD at the timing during the first timing when the potential of the signal waveform starts to transition from the second potential (high level) to the first potential (low level).

[0108] According to this configuration, the sensor controller 10 can reduce power consumption compared to the conventional configuration without connecting an element such as a switch to the output signal line Wout.

[0109] In this embodiment, the second potential (high level) is a potential of 5 V or more, and the second potential (high level) is a potential higher than the first potential (low level).

[0110] According to this configuration, the sensor controller 10 can reduce power consumption even when using the transmission driver 152A that operates at a voltage of 5V or more.

[0111] --- Second embodiment --- The first embodiment has been described above. Next, the second embodiment will be described.

[0112] <Circuit configuration> FIG. 7 is a diagram showing an example of a circuit configuration of an output circuit 15B including an intermediate potential supply unit 153B according to the second embodiment.

[0113] 7, the output circuit 15B includes a driver selection circuit 151, a plurality of transmission drivers 152A, and an intermediate potential supply unit 153B. In this figure, the driver selection circuit 151 selects n+1 transmission drivers 152A. The linear electrode 22 has a capacitance element Cout as a load capacitance. The capacitance of the capacitance element Cout is, for example, about 1200 pF.

[0114] The driver selection circuit 151 and the transmission driver 152A are the same as those described in the first embodiment, and therefore the description thereof will be omitted.

[0115] The intermediate potential supply unit 153B includes a potential generation unit 154B, a plurality of short-circuit control elements SWU and SWD, short-circuit signal lines Wsu and Wsd, a short-circuit control element SWr, and a capacitance element Cext.

[0116] The potential generating unit 154B includes, for example, a capacitive element Cext. The capacitive element Cext is, for example, a capacitor with a capacitance of about 1 uF, with one end connected to the short-circuit signal line Wsu and the other end connected to the short-circuit signal line Wsd. The capacitive element Cext charges or discharges electric charge according to the potential difference between the potentials supplied to the short-circuit signal lines Wsu and Wsd, and stabilizes the potentials of the short-circuit signal lines Wsu and Wsd.

[0117] The short-circuit control elements SWUU, SWUD, SWDU, SWDD, and SWr are, for example, switch elements or transistors. The short-circuit control elements SWUU, SWUD, SWDU, SWDD, and SWr short-circuit or open both ends according to the input signal. Specifically, on the one hand, the short-circuit control elements SWUU, SWUD, SWDU, SWDD, and SWr short-circuit both ends when the input signal is in a high state. On the other hand, the short-circuit control elements SWUU, SWUD, SWDU, SWDD, and SWr open both ends when the input signal is in a low state. Also, the short-circuit control elements SWUU, SWUD, SWDU, and SWDD are provided for each transmission driver 152A.

[0118] The short-circuit control element SWr shorts or opens the short-circuit signal line Ws and the reset voltage source Vrst in accordance with the reset signal RST output from the control circuit 12. One end of the short-circuit control element SWr is connected to the short-circuit signal line Wsu, and the other end is connected to one end of the short-circuit signal line Wsd. The short-circuit control element SWr shorts the short-circuit signal lines Wsu and Wds when shorted, and releases the short circuit between the short-circuit signal lines Wsu and Wds when open.

[0119] One end of the short-circuit control element SWUU is connected to the positive power supply terminal of the corresponding transmission driver 152A, and the other end is connected to the short-circuit signal line Wsu. The short-circuit control element SWUU shorts or opens both ends in accordance with a control signal CTUU output from the control circuit 12 for each short-circuit control element SWUU.

[0120] One end of each of the short-circuit control elements SWUD is connected to the positive power supply terminal of the corresponding transmission driver 152A, and the other end is connected to the short-circuit signal line Wsd. The short-circuit control elements SWUD short-circuit or open both ends in accordance with a control signal CTUD output from the control circuit 12 for each of the short-circuit control elements SWUD.

[0121] One end of the short-circuit control element SWDU is connected to the negative power supply terminal of the corresponding transmission driver 152, while the other end is connected to the short-circuit signal line Wsu. The short-circuit control element SWDU shorts or opens both ends in accordance with a control signal CTDU output from the control circuit 12 for each short-circuit control element SWDU.

[0122] One end of the short-circuit control element SWDD is connected to the negative power supply terminal of the corresponding transmission driver 152, while the other end is connected to the short-circuit signal line Wsd. The short-circuit control element SWDD shorts or opens both ends in accordance with a control signal CTDD output from the control circuit 12 for each short-circuit control element SWDD.

[0123] In the output circuit 15B configured as above, the control circuit 12 controls the state of the transmission driver 152A to a high impedance state at the timing when any of the input signals IN0 to INn transitions from a high state to a low state or from a low state to a high state. The control circuit 12 also assigns a value according to a code (e.g., an orthogonal code) to each transmission driver 152A, and determines whether the corresponding transmission driver 152A is connected to the short-circuit signal line Wsu or Wsd. Specifically, for example, when the value of the orthogonal code corresponding to a certain transmission driver 152A is "0", the control circuit 12 determines to connect the certain transmission driver 152A to the short-circuit signal line Wsu, while when the value of the orthogonal code corresponding to a certain transmission driver 152A is "1", the control circuit 12 determines to connect the certain transmission driver 152A to the short-circuit signal line Wsd. Note that it is preferable that the code that determines the value to be assigned to each transmission driver 152A contains values ​​of "0" and "1" at approximately the same ratio.

[0124] The control circuit 12 controls the short-circuit control element SWUU corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsu to a short-circuit state at the timing when the state of any of the input signals IN0 to INn transitions from a low state to a high state, while controlling the short-circuit control element SWDU corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsd to a short-circuit state. Also, the control circuit 12 controls the short-circuit control element SWUD corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsu to a short-circuit state at the timing when the state of any of the input signals IN0 to INn transitions from a high state to a low state, while controlling the short-circuit control element SWDD corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsd to a short-circuit state. Therefore, the output signal line Wout corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsu is short-circuited to one end of the capacitance element Cext via the short-circuit signal line Wsu, and the output signal line Wout corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsd is short-circuited to the other end of the capacitance element Cext via the short-circuit signal line Wsd. As a result, charge is exchanged between the output signal line Wout and one end of the capacitive element Cext via the short-circuit signal line Wsu, while charge is exchanged between the output signal line Wout and the other end of the capacitive element Cext via the short-circuit signal line Wsd, so that the potential of the output signal line Wout, the potentials of the short-circuit signal lines Wsu and Wsd, and the potentials at both ends of the capacitive element Cext reach an intermediate potential.

[0125] Next, when the potentials of each output signal line Wout, the short-circuit signal lines Wsu and Wsd, and both ends of the capacitance element Cext reach an intermediate potential, the control circuit 12 controls the state of the transmission driver 152A to an output state and controls the short-circuit control elements SWUU, SWUD, SWDU, and SWDD to an open state. As a result, the potential of each output signal line Wout transitions to a high level or a low level by the corresponding transmission driver 152A, and the transmission signals OUT0, OUT1, OUTn-1, and OUTn are transmitted via the linear electrodes 22.

[0126] <Flow of a series of operations related to the output circuit> The circuit configuration of the output circuit 15B has been described above. Next, the transition of the potential of each signal in the output circuit 15B will be described in detail. Fig. 8 is a timing chart showing the transition of the potential of each signal in the output circuit 15B according to the second embodiment. In this figure, it is assumed that the control circuit 12 determines to connect the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 to the short-circuit signal line Wsu, and to connect the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn to the short-circuit signal line Wsd.

[0127] At time t80, the control circuit 12 sets the reset signal RST to a low state, thereby opening both ends of the short-circuit control element SWr, thereby releasing the short-circuit state between the short-circuit signal lines Wsu and Wsd.

[0128] At time t81, the driver selection circuit 151 transitions the states of the input signals IN0 and INn-1 from a low state to a high state, while transitioning the states of the input signals IN1 and INn from a high state to a low state, and inputs the input signals IN0, IN1, INn-1, and INn to the corresponding transmitting drivers 152A.

[0129] At time t81, the control circuit 12 transitions the state of the output control signal EN from high to low, and sets the mode of each transmission driver 152A to the stop mode. Also at time t81, the control circuit 12 transitions the states of the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn from low to high, and outputs the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn to the short-circuit control elements SWUU0, SWUUn-1, SWDD1, and SWDDn, thereby shorting both ends of the short-circuit control elements SWUU0, SWUUn-1, SWDD1, and SWDDn.

[0130] As a result, at time t81, the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 is short-circuited to one end of the potential generator 154B via the short-circuit control elements SWUU0 and SWUUn-1, both ends of which are short-circuited. Also, at time t81, the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn is short-circuited to the other end of the potential generator 154B via the short-circuit control elements SWDD1 and SWDDn, both ends of which are short-circuited. At time t81, charges are supplied from the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn to the potential generator 154B, while charges are supplied from the potential generator 154B to the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1, so that the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn become intermediate potentials.

[0131] At time t82, the control circuit 12 changes the state of the output control signal EN from low to high, and sets the mode of each transmission driver 152A to the output mode. Also at time t82, the control circuit 12 changes the state of the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn from high to low, and outputs the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn to the short-circuit control elements SWUU0, SWUUn-1, SWDD1, and SWDDn, thereby opening both ends of the short-circuit control elements SWUU0, SWUUn-1, SWDD1, and SWDDn. As a result, at time t82, the short-circuit state between each transmission driver 152A and the potential generation unit 154B is released. At time t82, the potentials of the transmission signals OUT0 and OUTn-1 transition from the intermediate potential to a high level as charge is supplied from the corresponding transmission driver 152A, while the potentials of the transmission signals OUT1 and OUTn transition from the intermediate potential to a low level as charge is extracted from the corresponding transmission driver 152A.

[0132] At time t83, the driver selection circuit 151 transitions the states of the input signals IN0 and INn-1 from a high state to a low state, while transitioning the states of the input signals IN1 and INn from a hollow state to a high state, and inputs the input signals IN0, IN1, INn-1, and INn to the corresponding transmitting drivers 152A.

[0133] At time t83, the control circuit 12 transitions the state of the output control signal EN from a high state to a low state, and sets the mode of each transmission driver 152A to the stop mode. Also at time t83, the control circuit 12 transitions the states of the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn from a low state to a high state, and outputs the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn to the short-circuit control elements SWDU0, SWDUn-1, SWUD1, and SWUDn, thereby shorting both ends of the short-circuit control elements SWDU0, SWDUn-1, SWUD1, and SWUDn.

[0134] As a result, at time t83, the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 is short-circuited to one end of the potential generator 154B via the short-circuit control elements SWDU0 and SWDUn-1, both ends of which are short-circuited. Also, at time t83, the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn is short-circuited to the other end of the potential generator 154B via the short-circuit control elements SWUD1 and SWUDn, both ends of which are short-circuited. At time t83, charges are supplied from the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 to the potential generator 154B, while charges are supplied from the potential generator 154B to the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn, so that the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn become intermediate potentials.

[0135] At time t84, the control circuit 12 changes the state of the output control signal EN from low to high, and sets the mode of each transmission driver 152A to the output mode. Also at time t84, the control circuit 12 changes the state of the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn from high to low, and outputs the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn to the short-circuit control elements SWDU0, SWDUn-1, SWUD1, and SWUDn, thereby opening both ends of the short-circuit control elements SWDU0, SWDUn-1, SWUD1, and SWUDn. As a result, at time t84, the short-circuit state between each output signal line Wout and the potential generating unit 154B is released. At time t84, the potentials of the transmission signals OUT1 and OUTn transition from the intermediate potential to a high level as charge is supplied from the corresponding transmission driver 152A, while the potentials of the transmission signals OUT0 and OUTn-1 transition from the intermediate potential to a low level as charge is extracted from the corresponding transmission driver 152A.

[0136] The above describes the transition of the potential of each signal in the output circuit 15 B. Note that the flow of a series of processes in the output circuit 15 B is similar to that in the first embodiment, and therefore description thereof will be omitted.

[0137] <Effects> As described above, in the present embodiment, the sensor controller 10 includes a potential generating unit 154B having a capacitance element Cext, an intermediate potential supplying unit 153B having a first short-circuit signal line Wsu connected to one end of the capacitance element Cext, a second short-circuit signal line Wsd connected to the other end of the capacitance element Cext, a plurality of first short-circuit control elements SWUU each having one end short-circuited or open in accordance with a control signal CTUU, one end connected to a positive power supply terminal of a corresponding transmission driver 152A and the other end connected to the first short-circuit signal line Wsu, and a plurality of first short-circuit control elements SWUU each having one end short-circuited or open in accordance with a control signal CTUD, one end connected to a positive power supply terminal of a corresponding transmission driver 152A and the other end connected to the first short-circuit signal line Wsu. the other end connected to the first short-circuit signal line Wsd; and a plurality of third short-circuit control elements SWDU, both ends of which are short-circuited or opened in accordance with a control signal CTDU, one end of which is connected to the negative power supply terminal of the corresponding transmitting driver 152A, and the other end of which is connected to the first short-circuit signal line Wsu; and a plurality of fourth short-circuit control elements SWDD, both ends of which are short-circuited or opened in accordance with a control signal CTDD, one end of which is connected to the negative power supply terminal of the corresponding transmitting driver 152A, and the other end of which is connected to the second short-circuit signal line Wsd.

[0138] According to this configuration, the sensor controller 10 can stably supply an intermediate potential to the transmission driver 152A at a required timing by outputting an intermediate potential from the intermediate potential supply unit 153B having the potential generation unit 154B having the capacitance element Cext to the transmission driver 152A. Therefore, according to the present invention, the sensor controller 10 can reduce power consumption compared to the conventional configuration without connecting an element such as a switch to the output signal line Wout.

[0139] In addition, in this embodiment, the control circuit 12 determines whether the output signal line Wout will be connected to the first short-circuit signal line Wsu or the second short-circuit signal line Wsd for each transmission driver 152A, and when it is determined that the output signal line Wout is to be connected to the first short-circuit signal line Wsu, it controls at least one of the corresponding first short-circuit control element SWUU and third short-circuit control element SWDU so as to short-circuit at a first timing (times t81, t83, t85, and t87) and open at a second timing (times t82, t84, t86, and t88), while when it is determined that the output signal line Wout is to be connected to the second short-circuit signal line Wsd, it controls at least one of the corresponding second short-circuit control element SWUD and fourth short-circuit control element SWDD so as to short-circuit at a first timing (times t81, t83, t85, and t87) and open at a second timing (times t82, t84, t86, and t88).

[0140] According to this configuration, the sensor controller 10 can reduce power consumption by setting the output state of each transmission driver 152A to a high impedance state and providing a period during which an intermediate potential is stably supplied from the intermediate potential supply unit 153A to each output signal line Wout.

[0141] ---Third embodiment--- The second embodiment has been described above. Next, a third embodiment will be described.

[0142] <Circuit configuration> FIG. 9 is a diagram showing an example of a circuit configuration of an output circuit 15C including an intermediate potential supply unit 153C according to the third embodiment.

[0143] 9, the output circuit 15C includes a driver selection circuit 151, a plurality of transmission drivers 152A, and an intermediate potential supply unit 153C. In this figure, the driver selection circuit 151 selects n+1 transmission drivers 152A. The linear electrode 22 has a capacitance element Cout as a load capacitance. The capacitance of the capacitance element Cout is, for example, about 1200 pF. The driver selection circuit 151 and the transmission driver 152A are the same as those in the first embodiment, and therefore will not be described.

[0144] The intermediate potential supply unit 153C includes a potential generation unit 154A, a plurality of output control circuits 155A and 156A, a short-circuit signal line Ws, a short-circuit control element SWr, and a reset voltage source Vrst. Note that the potential generation unit 154A, the short-circuit control element SWr, and the reset voltage source Vrst are the same as those in the first embodiment, and therefore will not be described.

[0145] The output control circuit 155A is provided for each transmitting driver 152B, and makes a current path in a first direction from the corresponding output signal line Wout to the short-circuit signal line Ws conductive or non-conductive in accordance with a control signal CTD output for each corresponding transmitting driver 152B from the control circuit 12. The output control circuit 155A includes a short-circuit control element SWD and a current control element DD.

[0146] The output control circuit 156A is provided for each transmitting driver 152B, and makes a current path in a second direction from the short-circuit signal line Ws to the corresponding output signal line Wout conductive or non-conductive in accordance with a control signal CTU output for each corresponding transmitting driver 152B from the control circuit 12. The output control circuit 156A includes a short-circuit control element SWU and a current control element DU.

[0147] The short-circuit control elements SWU and SWD are, for example, switch elements or transistors, and short-circuit or open both ends according to the input signal. Specifically, the short-circuit control elements SWU and SWD short-circuit both ends when the input signal is in a high state, and open both ends when the input signal is in a low state.

[0148] One end of the short-circuit control element SWD is connected to the negative power supply terminal of the corresponding transmission driver 152A, and the other end is connected to the anode terminal of the current control element DD. The short-circuit control element SWD shorts or opens both ends in accordance with a control signal CTD.

[0149] One end of the short-circuit control element SWU is connected to the positive power supply terminal of the corresponding transmission driver 152A, while the other end is connected to the cathode terminal of the current control element DU. The short-circuit control element SWU shorts or opens both ends in accordance with a control signal CTU.

[0150] The current control element DD is, for example, a diode, and while a current path in a first direction from the short circuit control element SWD to the short circuit signal line Ws is conductive, a current path in a direction from the short circuit signal line Ws to the short circuit control element SWD is non-conductive. The current control element DD has an anode terminal connected to the short circuit control element SWD and a cathode terminal connected to the short circuit signal line Ws.

[0151] The current control element DU is, for example, a diode, with an anode terminal connected to the short-circuit signal line Ws and a cathode terminal connected to the short-circuit control element SWU. The current control element DU conducts a current path in a second direction from the short-circuit signal line Ws to the short-circuit control element SWU, while the current path from the short-circuit control element SWU to the short-circuit signal line Ws is non-conductive.

[0152] In the output circuit 15C configured as above, the control circuit 12 controls the short-circuit control element SWU to the short-circuit state at the timing when the state of any of the input signals IN0 to INn transitions from the low state to the high state. Also, the control circuit 12 controls the short-circuit control element SWD to the short-circuit state at the timing when the state of any of the input signals IN0 to INn transitions from the high state to the low state. As a result, a current path in a first direction from the positive power supply terminal of the transmission driver 152A, whose potential is at a high level, to the short-circuit signal line Ws is conducted, and a current path in a second direction from the short-circuit signal line Ws to the negative power supply terminal of the transmission driver 152A, whose potential is at a low level, is conducted, so that charges are supplied from the output signal line Wout, whose potential is at a high level, to the capacitance element Cext and the output signal line Wout, whose potential is at a low level, via the transmission driver 152A and the short-circuit signal line Ws. Also, charges are supplied from the voltage source Vmid and the capacitance element Cext to the output signal line Wout, whose potential is at a low level, via the short-circuit signal line Ws and the transmission driver 152A. As a result, the potentials of the output signal lines Wout and the short circuit signal line Ws reach the intermediate potential.

[0153] Next, the current control element DU makes the current path in the second direction non-conductive when the potential of the short-circuit signal line Ws falls below the potential of the corresponding output signal line Wout. Also, the current control element DD makes the current path in the first direction non-conductive when the potential of the corresponding output signal line Wout falls below the potential of the short-circuit signal line Ws. As a result, the potential of each output signal line Wout transitions from the intermediate potential to a high level or a low level by the corresponding transmission driver 152A, and the transmission signals OUT0, OUT1, OUTn-1, and OUTn are transmitted via the linear electrodes 22.

[0154] The above has described the configuration of the output circuit 15C. Next, a description will be given of another example of the circuit configuration of the output control circuit 156. Fig. 11A is a diagram showing another example of the circuit configuration of the output control circuit 156 according to the third embodiment.

[0155] As shown in FIG. 11A, the output control circuit 156B includes a logical NOT circuit INV3, transistors TR5 and TR6, a short-circuit control element SWcu, and a voltage source VB.

[0156] The logical negation circuit INV3 is, for example, an inverter circuit formed of MOS transistors, which performs a logical negation operation on the control signal CTU output from the control circuit 12 and outputs the result of the operation to the short-circuit control element SWcu and the gate terminal of the transistor TR5.

[0157] The transistors TR5 and TR6 are, for example, N-type MOS transistors, and extract or stop the extraction of charges from the drain terminal to the source terminal according to a signal input to the gate terminal. Specifically, when the state of the signal input to the gate terminal is high, the transistors TR5 and TR6 extract charges from the drain terminal to the source terminal, and when the state of the signal input to the gate terminal is low, the transistors TR5 and TR6 stop the extraction.

[0158] The transistor TR5 has a gate terminal connected to the output terminal of the logical NOT circuit INV3, a source terminal connected to the reference line GND, and a drain terminal connected to the gate terminal of the transistor TR6 and the other end of the short control element SWcu. The transistor TR5 extracts charge from the gate terminal of the transistor TR6 toward the reference line GND in response to a signal output from the logical NOT circuit INV3.

[0159] The transistor TR6 has a gate terminal connected to the drain terminal of the transistor TR5 and the other end of the short-circuit control element SWcu, a source terminal connected to the positive power supply terminal of the corresponding transmission driver 152A, and a drain terminal connected to the short-circuit signal line Ws. The transistor TR6 supplies the potential of the short-circuit signal line Ws to the corresponding output signal line Wout according to the potential of the gate terminal. When the potential of the short-circuit signal line Ws is the same as the potential of the positive power supply terminal of the corresponding transmission driver 152A, the supply of potential from the short-circuit signal line Ws to the corresponding output signal line Wout is stopped.

[0160] The voltage source VB generates an intermediate potential and supplies the generated intermediate potential to one end of the short-circuit control element SWcu. One end of the voltage source VB is connected to the short-circuit control element SWcu, and the other end is connected to the reference line GND.

[0161] The short-circuit control element SWcu is, for example, a transistor or a switch element, and has one end connected to a voltage source VB and the other end connected to the drain terminal of the transistor TR5 and the gate terminal of the transistor TR6. The short-circuit control element SWcu shorts or opens both ends according to the signal output from the logical negation circuit INV3. Specifically, the short-circuit control element SWcu shorts both ends when the state of the signal output from the logical negation circuit INV3 is low, and opens both ends when the signal is high.

[0162] The output control circuit 156B configured as above supplies the potential of the short-circuit signal line Ws to the corresponding output signal line Wout in accordance with the control signal CTU output from the control circuit 12. Specifically, when the control signal CTU is in a high state, the potential of the short-circuit signal line Ws is supplied to the positive power supply terminal of the corresponding transmission driver 152A, whereas when the control signal CTU is in a low state, the supply of the potential from the short-circuit signal line Ws to the positive power supply terminal of the corresponding transmission driver 152A is stopped. In addition, even when the potential of the short-circuit signal line Ws and the potential of the positive power supply terminal of the corresponding transmission driver 152A are the same, the output control circuit 156B stops the supply of the potential from the short-circuit signal line Ws to the positive power supply terminal of the corresponding transmission driver 152A.

[0163] The above describes the circuit configuration of the output control circuit 156B. Next, a description will be given of another example of the circuit configuration of the output control circuit 155. Fig. 11B is a diagram showing another example of the circuit configuration of the output control circuit 155 according to the third embodiment.

[0164] As shown in FIG. 11B, the output control circuit 155B includes transistors TR7 and TR8, a short-circuit control element SWcd, and a voltage source VB.

[0165] The transistors TR7 and TR8 are, for example, P-type MOS transistors. The transistors TR7 and TR8 supply the potential supplied to the source terminal to the drain terminal or stop the supply according to a signal input to the gate terminal. Specifically, when the state of the signal input to the gate terminal is low, the transistors TR7 and TR8 supply the potential supplied to the source terminal to the drain terminal, while when the state of the signal input to the gate terminal is high, the transistors TR7 and TR8 stop the supply.

[0166] The transistor TR7 has a gate terminal connected to the control circuit 12, a source terminal connected to the power supply line VDD, and a drain terminal connected to the gate terminal of the transistor TR8 and the other end of the short control element SWcd. The transistor TR7 supplies the potential (high level) of the power supply line VDD to the gate terminal of the transistor TR8 in accordance with a control signal CTD output from the control circuit 12.

[0167] The transistor TR8 has a gate terminal connected to the drain terminal of the transistor TR7 and the other end of the short-circuit control element SWcd, a source terminal connected to the negative power supply terminal of the corresponding transmission driver 152A, and a drain terminal connected to the short-circuit signal line Ws. The transistor TR8 supplies the potential of the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal line Ws according to the potential of the gate terminal. When the potential of the short-circuit signal line Ws is the same as the potential of the negative power supply terminal of the corresponding transmission driver 152A, the supply of potential from the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal line Ws is stopped.

[0168] The voltage source VB generates an intermediate potential and supplies the generated intermediate potential to one end of the short-circuit control element SWcd. One end of the voltage source VB is connected to the short-circuit control element SWcd, and the other end is connected to the reference line GND.

[0169] The short-circuit control element SWcd is, for example, a transistor or a switch element, and has one end connected to a voltage source VB and the other end connected to the drain terminal of the transistor TR7 and the gate terminal of the transistor TR8. The short-circuit control element SWcd shorts or opens both ends according to a control signal CTD output from the control circuit 12. Specifically, when the control signal CTD is in a high state, the short-circuit control element SWcd shorts both ends, and when the signal is in a low state, the short-circuit control element SWcd opens both ends.

[0170] The output control circuit 155B configured as above supplies the potential of the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal line Ws in accordance with the control signal CTD output from the control circuit 12. Specifically, when the control signal CTD is in a high state, the potential of the negative power supply terminal of the corresponding transmission driver 152A is supplied to the short-circuit signal line Ws, whereas when the control signal CTD is in a low state, the supply of the potential from the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal line Ws is stopped. In addition, even when the potential of the short-circuit signal line Ws and the potential of the negative power supply terminal of the corresponding transmission driver 152A are the same, the output control circuit 155B stops the supply of the potential from the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal line Ws.

[0171] The circuit configuration of the output control circuit 155B has been described above. Next, an example of the circuit configuration of the voltage source Vmid will be described. Fig. 14 is a diagram showing an example of the circuit configuration of the voltage source Vmid according to the third embodiment.

[0172] As shown in FIG. 14, the voltage source Vmid includes transistors TRv1, TRv2, TRv3, and TRv4, capacitance elements Cu and Cd, voltage sources Vc1 and Vc2, a power supply line VDD, and a reference line GND.

[0173] The transistors TRv1 and TRv2 are, for example, P-type MOS transistors, and supply the potential supplied to the source terminal to the drain terminal or stop the supply according to a signal input to the gate terminal. Specifically, when the state of the signal input to the gate terminal is low, the transistors TRv1 and TRv2 supply the potential supplied to the source terminal to the drain terminal, and when the state of the signal input to the gate terminal is high, the transistors TRv1 and TRv2 stop the supply.

[0174] The transistor TRv1 supplies the potential of the power supply line VDD connected to the source terminal to the short signal line Ws connected to the drain terminal in accordance with a control signal CTv1 input from the control circuit 12 to the gate terminal.

[0175] In accordance with a control signal CTv2 input from the control circuit 12 to the gate terminal, the transistor TRv2 supplies the potential of a voltage source Vc1 connected to the source terminal to a short-circuit signal line Ws connected to the drain terminal.

[0176] The transistors TRv3 and TRv4 are, for example, N-type MOS transistors, and extract or stop the extraction of electric charge from the drain terminal to the source terminal according to a signal input to the gate terminal. Specifically, when the state of the signal input to the gate terminal is high, the transistors TRv3 and TRv4 extract electric charge from the drain terminal to the source terminal, and when the state of the signal input to the gate terminal is low, the transistors TRv3 and TRv4 stop the extraction.

[0177] In accordance with a control signal CTv3 input from the control circuit 12 to the gate terminal, the transistor TRv3 supplies the potential of a voltage source Vc2 connected to the source terminal to a short-circuit signal line Ws connected to the drain terminal.

[0178] In accordance with a control signal CTv4 input from the control circuit 12 to the gate terminal, the transistor TRv4 supplies the potential of the reference line GND connected to the source terminal to the short-circuit signal line Ws connected to the drain terminal.

[0179] The voltage source Vc1 supplies a potential to the source terminal of the transistor TRv2 and the capacitive element Cu. The potential supplied by the voltage source Vc1 is, for example, two-thirds of the high-level potential. One end of the voltage source Vc1 is connected to the source terminal of the transistor TRv2 and the anode of the capacitive element Cu, and the other end is connected to the reference line GND.

[0180] The voltage source Vc2 supplies a potential to the source terminal of the transistor TRv3 and the capacitive element Cd. The potential supplied by the voltage source Vc1 is, for example, one third of the high-level potential. One end of the voltage source Vc1 is connected to the source terminal of the transistor TRv3 and the anode of the capacitive element Cd, and the other end is connected to the reference line GND.

[0181] The capacitance element Cu is, for example, an electrolytic capacitor, and stabilizes the potential of the voltage source Vc1. The capacitance element Cu has an anode connected to the source terminal of the transistor TRv2 and the voltage source Vc1, and a cathode connected to the reference line GND.

[0182] The capacitance element Cd is, for example, an electrolytic capacitor, and stabilizes the potential of the voltage source Vc2. The capacitance element Cd has an anode connected to the source terminal of the transistor TRv3 and the voltage source Vc2, and a cathode connected to the reference line GND.

[0183] The voltage source Vmid configured as above switches between four potentials, namely, a high level potential, two-thirds the high level potential, one-third the high level potential, and a low level potential, and supplies these to the short-circuit signal line Ws in accordance with the control signals CTv1, CTv2, CTv3, and CTv4 output from the control circuit 12. Note that the potentials supplied by the voltage sources Vc1 and Vc2 are not limited to the above-mentioned potentials, and may be, for example, one-half the high level potential.

[0184] <Flow of a series of operations related to the output circuit> An example of the circuit configuration of the voltage source Vmid has been described above. Next, the transition of the potential of each signal in the output circuit 15C will be described in detail. Fig. 10 is a timing chart showing the transition of the potential of each signal in the output circuit 15C according to the third embodiment.

[0185] At time t100, the control circuit 12 sets the reset signal RST to a low state, thereby opening both ends of the short-circuit control element SWr, thereby stopping the supply of the initial potential from the reset voltage source Vrst to the short-circuit signal line Ws.

[0186] At time t101, the driver selection circuit 151 transitions the states of the input signals IN0 and INn-1 from a low state to a high state, while transitioning the states of the input signals IN1 and INn from a high state to a low state, and inputs the input signals IN0, IN1, INn-1, and INn to the corresponding transmission drivers 152A. Also, at time t101, the control circuit 12 sets the state of the transmission driver 152A to a high impedance state.

[0187] At time t101, the control circuit 12 transitions the states of the control signals CTD0, CTDn-1, CTU1, and CTUn from high to low, and outputs the control signals CTD0, CTDn-1, CTU1, and CTUn to the short-circuit control elements SWD0, SWDn-1, SWU1, and SWUn, thereby opening both ends of the short-circuit control elements SWD0, SWDn-1, SWU1, and SWUn.

[0188] At time t102, when a predetermined time has elapsed from time t101, the control circuit 12 transitions the states of the control signals CTU0, CTUn-1, CTD1, and CTDn from low to high, and outputs the control signals CTU0, CTUn-1, CTD1, and CTDn to the short-circuit control elements SWU0, SWUn-1, SWD1, and SWDn, thereby shorting both ends of the short-circuit control elements SWU0, SWUn-1, SWD1, and SWDn. Also, at time t102, the control circuit 12 sets the state of the transmission driver 152A to the output state.

[0189] As a result, at time t102, charge is supplied from the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn via the short signal line Ws to the capacitive element Cext and the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1, and the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn begin to transition to the intermediate potential.

[0190] At time t103, the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn reach the intermediate potential. At time t103, the current control element DU makes the current path in the second direction non-conductive. Also, at time t103, the current control element DD makes the current path in the first direction non-conductive. Also, at time t103, the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 supplies charge to the corresponding output signal line Wout. As a result, at time t103, the potentials of the transmission signals OUT0 and OUTn-1 start to transition from the intermediate potential to a high level. Also, at time t103, the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn draws charge from the corresponding output signal line Wout. As a result, at time t103, the potentials of the transmission signals OUT1 and OUTn start to transition from the intermediate potential to a low level.

[0191] At time t104, the potentials of the transmission signals OUT0 and OUTn-1 reach a high level as a result of charge being supplied from the corresponding transmission driver 152A, and at time t104, the potentials of the transmission signals OUT1 and OUTn reach a low level as a result of charge being extracted from the corresponding transmission driver 152A.

[0192] At time t105, the control circuit 12 changes the states of the control signals CTU0, CTUn-1, CTD1, and CTDn from high to low, and outputs the control signals CTU0, CTUn-1, CTD1, and CTDn to the short-circuit control elements SWU0, SWUn-1, SWD1, and SWDn, thereby opening both ends of the short-circuit control elements SWU0, SWUn-1, SWD1, and SWDn. Also, at time t105, the control circuit 12 sets the state of the transmission driver 152A to a high impedance state.

[0193] At time t106, when a predetermined time has elapsed from time t105, the control circuit 12 changes the states of the control signals CTD0, CTDn-1, CTU1, and CTUn from low to high, and outputs the control signals CTD0, CTDn-1, CTU1, and CTUn to the short-circuit control elements SWD0, SWDn-1, SWU1, and SWUn, thereby shorting both ends of the short-circuit control elements SWD0, SWDn-1, SWU1, and SWUn. Also, at time t106, the control circuit 12 changes the state of the transmission driver 152A to the output state.

[0194] As a result, at time t106, charge is supplied from the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 via the short signal line Ws to the capacitive element Cext and the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn, and the potentials of the transmission signals OUT0, OUT1, OUTn-1 and OUTn begin to transition to the intermediate potential.

[0195] At time t107, the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn reach the intermediate potential. At time t107, the current control element DU makes the current path in the second direction non-conductive. Also, at time t107, the current control element DD makes the current path in the first direction non-conductive. Also, at time t107, the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn supplies charge to the corresponding output signal line Wout. As a result, at time t107, the potentials of the transmission signals OUT1 and OUTn start to transition from the intermediate potential to a high level. Also, at time t107, the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 draws charge from the corresponding output signal line Wout. As a result, at time t107, the potentials of the transmission signals OUT0 and OUTn-1 start to transition from the intermediate potential to a low level.

[0196] At time t108, the potentials of the transmission signals OUT1 and OUTn reach a high level as a result of charge being supplied from the corresponding transmission driver 152A, and at time t108, the potentials of the transmission signals OUT0 and OUTn-1 reach a low level as a result of charge being extracted from the corresponding transmission driver 152A.

[0197] The transition of the potential of each signal in the output circuit 15C has been described above. Next, the flow of a series of processes in the output circuit 15C will be described in detail. Fig. 16 is a flowchart showing the flow of a series of processes in the output circuit 15C according to the third embodiment.

[0198] (Step SP60) The transmission driver 152A amplifies the input signal IN input from the driver selection circuit 151 to a potential difference at which the signal can be transmitted from the linear electrode 22, and transmits the amplified signal as a transmission signal OUT to the corresponding output signal line Wout. Then, the process proceeds to step SP62.

[0199] (Step SP62) The control circuit 12 judges whether or not it is time for the signal waveform of the transmission signal OUT to rise from a low level to a high level. If the judgment is positive, the process proceeds to step SP64, whereas if the judgment is negative, the process proceeds to step SP68.

[0200] (Step SP64) The control circuit 12 controls each short circuit control element SWD so as to open both ends thereof, and then the process proceeds to step SP66.

[0201] (Step SP66) The control circuit 12 controls each short circuit control element SWU so that both ends are short circuited. As a result, a potential is supplied from the transmission driver 152A corresponding to the output signal line Wout whose potential is high level through the short circuit signal line Ws to the capacitance element Cext and the transmission driver 152A corresponding to the output signal line Wout whose potential is low level. The potentials of the output signal line Wout and the short circuit signal line Ws corresponding to each transmission driver 152Ani first transition to an intermediate potential. Then, the potential of the output signal line Wout corresponding to each transmission driver 152A transitions from the intermediate potential to a high level.

[0202] (Step SP68) The control circuit 12 judges whether or not it is time for the signal waveform of the transmission signal OUT to fall from a high level to a low level. If the judgment is positive, the process proceeds to step SP70. On the other hand, if the judgment is negative, the series of processes shown in FIG. 16 ends.

[0203] (Step SP70) The control circuit 12 controls each short circuit control element SWU so that both ends thereof are opened, and then the process proceeds to step SP72.

[0204] (Step SP72) The control circuit 12 controls each short circuit control element SWD so that both ends are short circuited. As a result, a potential is supplied from the transmission driver 152A corresponding to the output signal line Wout whose potential is high level through the short circuit signal line Ws to the capacitance element Cext and the transmission driver 152A corresponding to the output signal line Wout whose potential is low level. The potentials of the output signal line Wout and the short circuit signal line Ws corresponding to each transmission driver 152A first transition to an intermediate potential. Then, the potential of the output signal line Wout corresponding to each transmission driver 152A transitions from the intermediate potential to a low level.

[0205] <Effects> As described above, in this embodiment, the sensor controller 10 includes a control circuit 12 that transmits control signals CTU and CTD, and the intermediate potential supply unit 153C includes a short circuit signal line Ws, a plurality of first output control circuits 155A each having one end connected to the negative power supply terminal of the corresponding transmission driver 152A and the other end connected to the short circuit signal line Ws, and conducting only in a first direction from the negative power supply terminal to the short circuit signal line Ws in accordance with the control signal CTD, and a plurality of second output control circuits 156A each having one end connected to the positive power supply terminal of the corresponding transmission driver 152A and the other end connected to the short circuit signal line Ws, and conducting only in a second direction from the corresponding short circuit signal line Ws to the positive power supply terminal in accordance with the control signal CTU.

[0206] According to this configuration, the output control circuit 155A makes the current path in the first direction non-conductive at the timing when the potential of the short-circuit signal line Ws exceeds the potential of the negative power supply terminal of the corresponding transmission driver 152A. Also, the output control circuit 156A makes the current path in the second direction non-conductive at the timing when the potential of the positive power supply terminal of the corresponding transmission driver 152A exceeds the potential of the short-circuit signal line Ws. Therefore, according to the present invention, the sensor controller 10 supplies the intermediate potential from the intermediate potential supply unit 153C to the transmission driver 152A only for a necessary period, so that the sensor controller 10 can reduce power consumption compared to the conventional configuration without connecting an element such as a switch to the output signal line Wout.

[0207] In this embodiment, the first output control circuit 155B has an N-type transistor whose source terminal is connected to the negative power supply terminal, whose drain terminal is connected to the short signal line Ws, and whose gate terminal is supplied with a first potential (low level) or an intermediate potential from a voltage source VB different from the transmission driver 152A and the intermediate potential supply unit 153C. The second output control circuit 156B has a P-type transistor whose source terminal is connected to the positive power supply terminal, whose drain terminal is connected to the short signal line Ws, and whose gate terminal is supplied with a second potential (high level) or an intermediate potential from a voltage source VB different from the transmission driver 152A and the intermediate potential supply unit 153C.

[0208] According to this configuration, the output control circuits 155A and 156A are configured by transistors instead of the current control elements DU and DD, so that the cost of parts can be reduced.

[0209] In this embodiment, the control circuit 12 controls the first output control circuit 155A to be conductive only in the second direction at the timing when the potential of the signal waveform of the corresponding transmission driver 152A falls and to be non-conductive at the timing when the potential of the signal waveform of the corresponding transmission driver 152A rises. The control circuit 12 controls the second output control circuit 156A to be conductive only in the first direction at the timing when the potential of the signal waveform of the corresponding transmission driver 152A rises and to be non-conductive at the timing when the potential of the signal waveform of the corresponding transmission driver 152A falls.

[0210] According to this configuration, the sensor controller 10 supplies an intermediate potential from the intermediate potential supply unit 153C to the transmission driver 152A only for the required period, so that the sensor controller 10 can reduce power consumption compared to the conventional configuration without connecting an element such as a switch to the output signal line Wout.

[0211] In addition, in this embodiment, the intermediate potential supply unit 153C has a potential generation unit 154B having a voltage source Vmid or a capacitive element Cext separate from the transmission driver 152A, and supplies an intermediate potential to the transmission driver 152A by outputting a voltage from the potential generation unit 154B during a period from the timing at which a transition from a first potential (low level) to a second potential (high level) or a transition from the second potential (high level) to the first potential (low level) begins until the potential of the positive power supply terminal or the negative power supply terminal of the transmission driver 152A reaches the intermediate potential.

[0212] According to this configuration, the sensor controller 10 supplies an intermediate potential from the intermediate potential supply unit 153C to the transmission driver 152A only for the required period, so that the sensor controller 10 can reduce power consumption compared to the conventional configuration without connecting an element such as a switch to the output signal line Wout.

[0213] ---Fourth embodiment--- The third embodiment has been described above. Next, a fourth embodiment will be described.

[0214] <Circuit configuration> FIG. 12 is a diagram showing an example of a circuit configuration of an output circuit 15D including an intermediate potential supply unit 153D according to the fourth embodiment.

[0215] As shown in Fig. 12, the output circuit 15D includes a driver selection circuit 151, a plurality of transmission drivers 152A, and an intermediate potential supply unit 153D. In this figure, the driver selection circuit 151 selects n+1 transmission drivers 152A. The linear electrode 22 has a capacitance element Cout as a load capacitance. The capacitance of the capacitance element Cout is, for example, about 1200 pF. The driver selection circuit 151 and the transmission driver 152A are the same as those in the first embodiment, and therefore will not be described.

[0216] The intermediate potential supply unit 153D includes a potential generation unit 154B, a plurality of output control circuits 155BD and 156C, short-circuit signal lines Wsu and Wsd, and a short-circuit control element SWr. Note that the potential generation unit 154B and the short-circuit control element SWr are the same as those described above, and therefore will not be described here.

[0217] The output control circuit 155B includes, for example, short-circuit control elements SWDU0 and SWDD0 and a current control element DD. The output control circuit 155B is provided for each corresponding transmission driver 152B, and supplies the potential of the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal lines Wsu and Wsd in accordance with the control signals CTDD and CTDD output from the control circuit 12 for each corresponding transmission driver 152B. Specifically, when the control signal CTDU is in a high state, the output control circuit 155B supplies the potential of the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal line Wsu, while when the control signal CTDU is in a low state, the output control circuit 155B stops the supply of the potential from the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit signal line Wsu. In addition, when the control signal CTDD is in a high state, the output control circuit 155B supplies the potential of the negative power supply terminal of the corresponding transmitting driver 152A to the short-circuit signal line Wsd, while when the control signal CTDD is in a low state, the output control circuit 155B stops supplying the potential from the negative power supply terminal of the corresponding transmitting driver 152A to the short-circuit signal line Wsd.

[0218] The output control circuit 156B includes, for example, short-circuit control elements SWUU and SWUD and a current control element DU. The output control circuit 156B is provided for each corresponding transmission driver 152A, and supplies the potentials of the short-circuit signal lines Wsu and Wsd to the positive power supply terminal of the corresponding transmission driver 152A in accordance with the control signals CTUU and CTUD output from the control circuit 12 for each corresponding transmission driver 152A. Specifically, when the control signal CTUU is in a high state, the output control circuit 156B supplies the potential of the short-circuit signal line Wsu to the positive power supply terminal of the corresponding transmission driver 152A, while when the control signal CTUU is in a low state, the output control circuit 156B stops the supply of the potential from the short-circuit signal line Wsu to the positive power supply terminal of the corresponding transmission driver 152A. In addition, when the control signal CTUD is in a high state, the output control circuit 156B supplies the potential of the short-circuit signal line Wsd to the positive power supply terminal of the corresponding transmission driver 152A, while when the control signal CTUD is in a low state, the output control circuit 156B stops the supply of potential from the short-circuit signal line Wsd to the positive power supply terminal of the corresponding transmission driver 152A.

[0219] The short-circuit control elements SWDU, SWDD, SWUU, and SWUD are, for example, transistors or switch elements, and short-circuit or open both ends according to the input signal. Specifically, the short-circuit control elements SWDU, SWDD, SWUU, and SWUD short-circuit both ends when the input signal is in a high state, and open both ends when the input signal is in a low state.

[0220] One end of the short-circuit control element SWDU is connected to the short-circuit signal line Wsu, and the other end is connected to the cathode terminal of the current control element DD. The short-circuit control element SWDU shorts or opens both ends of the short-circuit control element SWDU in accordance with a control signal CTDU output from the control circuit 12 to each corresponding transmission driver 152A.

[0221] The short-circuit control element SWDD has one end connected to the short-circuit signal line Wsd and the other end connected to the cathode terminal of the current control element DD. The short-circuit control element SWDD shorts or opens both ends in response to a control signal CTDD output from the control circuit 12 for each corresponding transmission driver 152A.

[0222] One end of the short-circuit control element SWUU is connected to the short-circuit signal line Wsu, and the other end is connected to the anode terminal of the current control element DU. The short-circuit control element SWUU shorts or opens both ends of the short-circuit control element SWUU in accordance with a control signal CTUU output from the control circuit 12 for each corresponding transmission driver 152A.

[0223] The short-circuit control element SWUD has one end connected to the short-circuit signal line Wsd and the other end connected to the anode terminal of the current control element DU. The short-circuit control element SWUD shorts or opens both ends in accordance with a control signal CTUD output from the control circuit 12 for each corresponding transmission driver 152A.

[0224] The current control element DD is, for example, a diode, with an anode terminal connected to the negative power supply terminal of the corresponding transmission driver 152A and a cathode terminal connected to the other end of the short-circuit control element SWDU and the other end of SWDD. The current control element DD conducts a current path from the negative power supply terminal of the corresponding transmission driver 152A to the short-circuit control elements SWDU and SWDD, while the current path from the short-circuit control elements SWDU and SWDD to the negative power supply terminal of the corresponding transmission driver 152A is non-conductive.

[0225] The current control element DU is, for example, a diode, with an anode terminal connected to the short-circuit control elements SWUU and SWUD and a cathode terminal connected to the positive power supply terminal of the corresponding transmission driver 152 A. The current control element DU conducts a current path from the short-circuit control elements SWUU and SWUD to the positive power supply terminal of the corresponding transmission driver 152 A, while the current path from the positive power supply terminal of the corresponding transmission driver 152 A to the short-circuit control elements SWUU and SWUD is non-conductive.

[0226] In the output circuit 15D configured as above, the control circuit 12 assigns a value according to a code (e.g., an orthogonal code) to each transmission driver 152A, and determines whether the corresponding transmission driver 152A is connected to the short-circuit signal line Wsu or Wsd. Specifically, when the value of the orthogonal code corresponding to a certain transmission driver 152A is "0", the control circuit 12 determines to connect the certain transmission driver 152A to the short-circuit signal line Wsu, while when the value of the orthogonal code corresponding to a certain transmission driver 152A is "1", the control circuit 12 determines to connect the certain transmission driver 152A to the short-circuit signal line Wsd. Note that the code that determines the value to be assigned to each transmission driver 152A preferably contains values ​​of "0" and "1" at approximately the same ratio.

[0227] At the timing when any of the input signals IN0 to INn transitions from a high state to a low state, the control circuit 12 controls the short-circuit control element SWDU corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsu to a short-circuit state, while controlling the short-circuit control element SWDD corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsd to a short-circuit state. Therefore, the direction from the transmission driver 152A determined to be connected to the short-circuit signal line Wsu to the short-circuit signal line Wsu and the direction from the transmission driver 152A determined to be connected to the short-circuit signal line Wsd to the short-circuit signal line Wsd are respectively conductive. As a result, charge is supplied from the corresponding transmission driver 152A to one end of the capacitance element Cext via the short-circuit signal line Wsu, while charge is supplied from the corresponding transmission driver 152A to the other end of the capacitance element Cext via the short-circuit signal line Wsd, so that the potential of the output signal line Wout, the potentials of the short-circuit signal lines Wsu and Wsd, and the potentials at both ends of the capacitance element Cext reach an intermediate potential.

[0228] Next, the control circuit 12 controls the short-circuit control elements SWDU and SWDD to an open state at the timing when the potentials of each output signal line Wout, the short-circuit signal lines Wsu and Wsd, and both ends of the capacitance element Cext reach an intermediate potential. As a result, the potential of the output signal line Wout corresponding to each transmission driver 152A transitions to a low level by the corresponding transmission driver 152A, and the transmission signals OUT0, OUT1, OUTn-1, and OUTn are transmitted via the linear electrodes 22.

[0229] In response to this, the control circuit 12 controls the short-circuit control element SWUU corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsu to a short-circuit state at the timing when the state of any of the input signals IN0 to INn transitions from a low state to a high state, while controlling the short-circuit control element SWDU corresponding to the transmission driver 152A determined to be connected to the short-circuit signal line Wsd to a short-circuit state. Therefore, the direction from the short-circuit signal line Wsu to the transmission driver 152A determined to be connected to the short-circuit signal line Wsu and the direction from the short-circuit signal line Wsd to the transmission driver 152A determined to be connected to the short-circuit signal line Wsd are each conductive. As a result, charge is supplied from one end of the capacitance element Cext to the corresponding transmission driver 152A via the short-circuit signal line Wsu, while charge is supplied from the other end of the capacitance element Cext to the corresponding transmission driver 152A via the short-circuit signal line Wsd, and the potential of the output signal line Wout, the potentials of the short-circuit signal lines Wsu and Wsd, and the potentials at both ends of the capacitance element Cext reach an intermediate potential.

[0230] Next, the control circuit 12 controls the short control elements SWUU and SWUD to an open state at the timing when the potentials of each output signal line Wout, the short signal lines Wsu and Wsd, and both ends of the capacitance element Cext reach an intermediate potential. As a result, the potential of the output signal line Wout corresponding to each transmission driver 152A transitions to a high level by the corresponding transmission driver 152B, and the transmission signals OUT0, OUT1, OUTn-1, and OUTn are transmitted via the linear electrodes 22.

[0231] <Flow of a series of operations related to the output circuit> The configuration of the output circuit 15D has been described above. Next, the transition of the potential of each signal in the output circuit 15D will be described in detail. Fig. 13 is a timing chart showing the transition of the potential of each signal in the output circuit 15D according to the fourth embodiment. In this figure, it is assumed that the control circuit 12 determines to connect the output signal lines Wout corresponding to the transmission signals OUT0 and OUTn-1 to the short-circuit signal line Wsu, and to connect the output signal lines Wout corresponding to the transmission signals OUT1 and OUTn to the short-circuit signal line Wsd.

[0232] At time t120, the control circuit 12 sets the reset signal RST to a low state, thereby opening both ends of the short-circuit control element SWr, thereby opening both ends of the capacitance element Cext.

[0233] At time t121, the driver selection circuit 151 transitions the states of the input signals IN0 and INn-1 from a low state to a high state, while transitioning the states of the input signals IN1 and INn from a high state to a low state, and inputs the input signals IN0, IN1, INn-1, and INn to the corresponding transmitting drivers 152A.

[0234] At time t121, the control circuit 12 changes the states of the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn from high to low, and outputs the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn to the corresponding short-circuit control elements SWUU and SWDD, thereby opening both ends of the short-circuit control elements SWUU and SWDD. Also, at time t121, the control circuit 12 sets the state of the transmission driver 152A to a high impedance state.

[0235] At time t122, when a predetermined time has elapsed from time t121, the control circuit 12 transitions the states of the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn from low to high, and outputs the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn to the corresponding short-circuit control elements SWDU and SWUD, thereby shorting both ends of the corresponding short-circuit control elements SWDU and SWUD. Also, at time t122, the control circuit 12 sets the state of the transmission driver 152A to the output state.

[0236] As a result, at time t122, charge is supplied to the other end of the capacitive element Cext from the transmitting driver 152A corresponding to the transmitting signals OUT1 and OUTn via the short-circuit signal line Wsu, while charge is supplied from one end of the capacitive element Cext to the transmitting driver 152A corresponding to the transmitting signals OUT0 and OUTn-1 via the short-circuit signal line Wsd, causing the potentials of the transmitting signals OUT0, OUT1, OUTn-1, and OUTn to begin transitioning to an intermediate potential.

[0237] At time t123, the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn reach the intermediate potential. As a result, at time t123, the current control elements DU and DD become non-conductive. Also, at time t123, the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 supplies charge to the corresponding output signal line Wout. As a result, at time t123, the potentials of the transmission signals OUT0 and OUTn-1 start to transition from the intermediate potential to a high level. Also, at time t123, the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn draws charge from the corresponding output signal line Wout. As a result, at time t123, the potentials of the transmission signals OUT1 and OUTn start to transition from the intermediate potential to a low level.

[0238] At time t124, the potentials of the transmission signals OUT0 and OUTn-1 reach a high level as a result of charge being supplied from the corresponding transmission driver 152A, and at time t124, the potentials of the transmission signals OUT1 and OUTn reach a low level as a result of charge being extracted from the corresponding transmission driver 152A.

[0239] At time t125, the control circuit 12 changes the states of the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn from high to low, and outputs the control signals CTDU0, CTDUn-1, CTUD1, and CTUDn to the corresponding short-circuit control elements SWDU and SWUD, thereby opening both ends of the corresponding short-circuit control elements SWDU and SWUD. Also, at time t125, the control circuit 12 changes the state of the transmission driver 152A to a high impedance state.

[0240] At time t126, when a predetermined time has elapsed from time t125, the control circuit 12 transitions the states of the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn from low to high, and outputs the control signals CTUU0, CTUUn-1, CTDD1, and CTDDn to the corresponding short-circuit control elements SWUU and SWDD, thereby shorting both ends of the corresponding short-circuit control elements SWUU and SWDD. Also, at time t126, the control circuit 12 changes the state of the transmission driver 152A to the output state.

[0241] As a result, at time t126, charge is supplied to one end of the capacitive element Cext from the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 via the short-circuit signal line Wsu, and charge is supplied from the other end of the capacitive element Cext to the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn via the short-circuit signal line Wsd, causing the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn to begin transitioning to the intermediate potential.

[0242] At time t127, the potentials of the transmission signals OUT0, OUT1, OUTn-1, and OUTn reach the intermediate potential. As a result, at time t127, the current control elements DU and DD become non-conductive. Also, at time t127, the transmission driver 152A corresponding to the transmission signals OUT1 and OUTn supplies charge to the corresponding output signal line Wout. As a result, at time t127, the potentials of the transmission signals OUT1 and OUTn start to transition from the intermediate potential to a high level. Also, at time t127, the transmission driver 152A corresponding to the transmission signals OUT0 and OUTn-1 draws charge from the corresponding output signal line Wout. As a result, at time t127, the potentials of the transmission signals OUT0 and OUTn-1 start to transition from the intermediate potential to a low level.

[0243] At time t128, the potentials of the transmission signals OUT1 and OUTn reach a high level as a result of charge being supplied from the corresponding transmission driver 152A. Also, at time t128, the potentials of the transmission signals OUT0 and OUTn-1 reach a low level as a result of charge being extracted from the corresponding transmission driver 152A.

[0244] The above describes the transition of the potential of each signal in the output circuit 15D. Note that the flow of a series of processes in the output circuit 15D is the same as in the third embodiment, and therefore a description thereof will be omitted.

[0245] <Effects> As described above, in this embodiment, the sensor controller 10 is connected to the touch sensor 20 in which the linear electrodes 21 and 22 are arranged in a planar shape. The sensor controller 10 includes a plurality of transmission drivers 152A having a positive power supply terminal and a negative power supply terminal, generating a signal waveform that transitions between a first potential (low level) supplied to the negative power supply terminal and a second potential (high level) that is supplied to the positive power supply terminal and is a potential higher than the first potential (low level), and outputting the signal waveform to a corresponding linear electrode 22 as a transmission signal; and an intermediate potential supply unit 153D that generates an intermediate potential between the first potential (low level) and the second potential (high level), supplies the intermediate potential to at least one of the positive power supply terminal and the negative power supply terminal of at least one transmission driver 152A during a period from a time point when the potential of the signal waveform starts to transition from the first potential (low level) to the second potential (high level) or from the second potential (high level) to the first potential (low level) to a time point when the potential of the positive power supply terminal and the negative power supply terminal of the transmission driver 152A reaches the intermediate potential, and stops supplying the intermediate potential at the timing when the potential of at least one of the positive power supply terminal and the negative power supply terminal reaches the intermediate potential.

[0246] According to this configuration, the sensor controller 10 supplies an intermediate potential from the intermediate potential supply unit 153D to the transmission driver 152A only for a necessary period, so that the sensor controller 10 can suppress shoot-through current and reduce power consumption compared to the conventional configuration.

[0247] In addition, in this embodiment, the intermediate potential supply unit 153D has a plurality of first output control circuits 155B that extract charge from the corresponding transmitting driver 152A at the timing when the potential of the signal waveform of the corresponding transmitting driver 152A falls, and a plurality of second output control circuits 156B that supply an intermediate potential to the corresponding transmitting driver 152A at the timing when the potential of the signal waveform of the corresponding transmitting driver 152A rises.

[0248] According to this configuration, the sensor controller 10 supplies an intermediate potential from the intermediate potential supply unit 153D to the transmission driver 152A only for a necessary period, so that the sensor controller 10 can suppress shoot-through current and reduce power consumption compared to the conventional configuration.

[0249] In addition, in this embodiment, the sensor controller 10 includes a control circuit 12 that transmits control signals CTUU, CTUD, CTDU, and CTDD, the intermediate potential supply unit 153D has a first short-circuit signal line Wsu and a second short-circuit signal line Wsd, the first output control circuit 155B has one end connected to the negative power supply terminal of the corresponding transmission driver 152A and the other end connected to the first short-circuit signal line Wsu and the second short-circuit signal line Wsd, and is conductive or non-conductive in the direction from the corresponding negative power supply terminal to the first short-circuit signal line Wsu or the second short-circuit signal line Wsd according to the control signals CTDU and CTDD, and the second output control circuit 156B has one end connected to the positive power supply terminal of the corresponding transmission driver 152A and the other end connected to the first short-circuit signal line Wsu and the second short-circuit signal line Wsd, and is conductive or non-conductive in the direction from the first short-circuit signal line Wsu and the second short-circuit signal line Wsd to the positive power supply terminal of the corresponding transmission driver 152A according to the control signals CTUU and CTUD.

[0250] According to this configuration, the sensor controller 10 makes the current path from the negative power supply terminal of the corresponding transmission driver 152A toward the short-circuit signal lines Wsu and Wsd non-conductive at the timing when the potential of the short-circuit signal lines Wsu and Wsd exceeds the potential of the negative power supply terminal of the corresponding transmission driver 152A. Also, the sensor controller 10 makes the current path from the short-circuit signal lines Wsu and Wsd toward the positive power supply terminal of the corresponding transmission driver 152A non-conductive at the timing when the potential of the positive power supply terminal of the corresponding transmission driver 152A exceeds the potential of the short-circuit signal lines Wsu and Wsd. Therefore, according to the present invention, the sensor controller 10 supplies the intermediate potential to the transmission driver 152A from the intermediate potential supply unit 153D only for a necessary period, so that the sensor controller 10 can suppress the through current and reduce power consumption compared to the conventional configuration.

[0251] --- Variation --- The present invention is not limited to the above-described embodiment. In other words, the above-described embodiment may be modified by a person skilled in the art as appropriate, and the modifications may be included within the scope of the present invention as long as they include the characteristics of the present invention. In addition, the elements of the above-described embodiment and the modifications described below may be combined to the extent technically possible, and the combinations of these may be included within the scope of the present invention as long as they include the characteristics of the present invention.

[0252] For example, in the above embodiment, it has been explained that it is desirable for the code that determines the value to be assigned to each transmission driver 152 to contain values ​​of "0" and "1" in approximately equal proportions, but this code may also contain values ​​of "0" and "1" in approximately a 45:55 or 55:45 ratio.

[0253] Furthermore, in the above embodiment, one transmission driver 152 is provided for each linear electrode 22, but one transmission driver 152 may be provided for each linear electrode 21. That is, the transmission driver 152 may amplify an input signal IN input from the driver selection circuit 151 to a potential difference at which the signal can be transmitted from the linear electrode 21, and transmit the amplified signal as a transmission signal OUT to the corresponding linear electrode 21 via the output signal line Wout.

[0254] The touch sensor 20 may also have a switch element. Furthermore, at least one of the linear electrodes 22 may detect the depression of the switch element.

[0255] According to this configuration, even when at least one of the linear electrodes 22 detects a press of a switch of the touch sensor 20, the through current can be suppressed and power consumption can be reduced.

[0256] In addition, in the above embodiments, the transmission driver 152 has a function of switching the output state between an output state and a high-impedance state. However, in the third and fourth embodiments, the transmission driver 152 does not have to have a function of switching the output state between an output state and a high-impedance state.

[0257] According to this configuration, the transmission driver 152 can reduce power consumption even if it does not have a function for switching the output state between the output state and the high impedance state. [Explanation of symbols]

[0258] 10: sensor controller, 20: touch sensor, 152: transmission driver, 153: intermediate potential supply unit

Claims

1. A sensor controller connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, a plurality of transmission drivers each having a first terminal to which a first potential is supplied and a second terminal to which a second potential higher than the first potential is supplied, the transmission drivers generating signal waveforms that transition between the first potential and the second potential and outputting the signal waveforms as transmission signals to the corresponding detection electrodes; an intermediate potential supplying unit that has a potential generating unit including a voltage source or a capacitive element separate from the transmission driver, and supplies an intermediate potential between the first potential and the second potential to at least one of the first terminal and the second terminal by outputting a voltage from the potential generating unit; A sensor controller comprising:

2. 2. The sensor controller according to claim 1, wherein the intermediate potential supply unit outputs a voltage from the potential generating unit at a first timing when the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential.

3. The sensor controller according to claim 2 , wherein an output side of the potential generating unit is connected to two or more of the plurality of transmitting drivers.

4. A control circuit for transmitting a control signal; the transmission driver has an output mode in which the transmission signal is output, and a stop mode in which the supply of the second potential from a power supply line to the second terminal and the supply of the first potential from a reference line to the first terminal are stopped, and an output state is set to a high impedance state; 4. The sensor controller according to claim 3, wherein the control circuit controls the transmission driver to switch to the stop mode at the first timing, and controls the transmission driver to switch to the output mode at a second timing that is a predetermined time after the first timing.

5. the intermediate potential supply unit includes a plurality of first short-circuit control elements each having both ends shorted or opened in accordance with the control signal, one end connected to the corresponding second terminal, and the other end connected to the output side of the potential generation unit, and a plurality of second short-circuit control elements each having both ends shorted or opened in accordance with the control signal, one end connected to the corresponding first terminal, and the other end connected to the output side of the potential generation unit, The sensor controller of claim 4, wherein the control circuit controls at least one of the first short-circuit control element and the second short-circuit control element to be short-circuited at the first timing, and controls at least one of the first short-circuit control element and the second short-circuit control element shorted at the first timing to be opened at the second timing.

6. A sensor controller as described in claim 5, wherein the control circuit controls the first short-circuit control element to short-circuit at the timing during the first timing when the potential of the signal waveform starts to transition from the first potential to the second potential, and controls the second short-circuit control element to short-circuit at the timing during the first timing when the potential of the signal waveform starts to transition from the second potential to the first potential.

7. the potential generating unit has the capacitance element, The intermediate potential supply unit is a first short signal line connected to one end of the capacitive element; a second short-circuit signal line connected to the other end of the capacitive element; a plurality of first short-circuit control elements each having both ends shorted or opened in accordance with the control signal, one end connected to the second terminal of the corresponding transmission driver, and the other end connected to the first short-circuit signal line; a plurality of second short-circuit control elements each having both ends shorted or opened in accordance with the control signal, one end connected to the second terminal of the corresponding transmission driver, and the other end connected to the second short-circuit signal line; a plurality of third short-circuit control elements each having both ends shorted or opened in accordance with the control signal, one end connected to the first terminal of the corresponding transmission driver, and the other end connected to the first short-circuit signal line; a plurality of fourth short-circuit control elements each having both ends shorted or opened in accordance with the control signal, one end connected to the first terminal of the corresponding transmission driver, and the other end connected to the second short-circuit signal line; The sensor controller of claim 4 .

8. 8. The sensor controller according to claim 7, wherein the control circuit determines, for each of the transmitting drivers, to which of the first short-circuit signal line and the second short-circuit signal line the transmitting driver is to be connected, and when it is determined to connect the transmitting driver to the first short-circuit signal line, controls at least one of the first short-circuit control element and the third short-circuit control element corresponding to short-circuit at the first timing and open at the second timing, and when it is determined to connect the transmitting driver to the second short-circuit signal line, controls at least one of the second short-circuit control element and the fourth short-circuit control element corresponding to short-circuit at the first timing and open at the second timing.

9. A control circuit for transmitting a control signal; The intermediate potential supply unit is A shorted signal line; a plurality of first output control circuits, each having one end connected to the first terminal of the corresponding one of the transmission drivers and the other end connected to the short-circuit signal line, and each of which is conductive only in a first direction from the first terminal to the short-circuit signal line in accordance with the control signal; a plurality of second output control circuits, each having one end connected to the second terminal of the corresponding one of the transmission drivers and the other end connected to the short-circuit signal line, and each of which is conductive only in a second direction from the corresponding short-circuit signal line to the second terminal in accordance with the control signal; The sensor controller of claim 3 .

10. the first output control circuit has an N-type transistor having a source terminal connected to the first terminal, a drain terminal connected to the short signal line, and a gate terminal to which the first potential is supplied or to which the intermediate potential is supplied from a voltage source different from the transmission driver and the intermediate potential supply unit; 10. The sensor controller according to claim 9, wherein the second output control circuit has a P-type transistor having a source terminal connected to the second terminal, a drain terminal connected to the short-circuit signal line, and a gate terminal to which the second potential is supplied or to which the intermediate potential is supplied from a voltage source different from the transmission driver and the intermediate potential supply unit.

11. 10. The sensor controller of claim 9, wherein the control circuit controls the first output control circuit so as to be conductive only in the first direction when the potential of the signal waveform of the corresponding transmitting driver falls and to be non-conductive when the potential of the signal waveform of the corresponding transmitting driver rises, and controls the second output control circuit so as to be conductive only in the second direction when the potential of the signal waveform of the corresponding transmitting driver rises and to be non-conductive when the potential of the signal waveform of the corresponding transmitting driver falls.

12. A sensor controller connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, a plurality of transmission drivers each having a first terminal to which a first potential is supplied and a second terminal to which a second potential higher than the first potential is supplied, the transmission drivers generating signal waveforms that transition between the first potential and the second potential and outputting the signal waveforms as transmission signals to the corresponding detection electrodes; an intermediate potential supply unit that generates an intermediate potential between the first potential and the second potential, supplies the intermediate potential to at least one of the first terminal and the second terminal of at least one of the transmission drivers, and stops supplying the intermediate potential; A sensor controller comprising:

13. 13. The sensor controller of claim 12, wherein the intermediate potential supply unit supplies the intermediate potential to at least one of the first terminal and the second terminal of at least one of the transmission drivers during a period from a time point when the potential of the signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential to a time point when the potentials of the first terminal and the second terminal of the transmission driver reach the intermediate potential, and stops supplying the intermediate potential at a timing when the potential of at least one of the first terminal and the second terminal reaches the intermediate potential.

14. The intermediate potential supply unit is a plurality of first output control circuits that extract electric charges from the corresponding transmission drivers at timings when the potential of the signal waveform of the corresponding transmission driver falls; a plurality of second output control circuits each supplying the intermediate potential to a corresponding one of the transmission drivers at a timing when the potential of the signal waveform of the corresponding one of the transmission drivers rises; The sensor controller of claim 13 .

15. 14. The sensor controller of claim 13, wherein the intermediate potential supply unit has a potential generating unit having a voltage source or a capacitive element separate from the transmission driver, and supplies the intermediate potential to the transmission driver by outputting a voltage from the potential generating unit during a period from a timing at which a transition from the first potential to the second potential or a transition from the second potential to the first potential starts until the potential of the first terminal or the second terminal of the transmission driver reaches the intermediate potential.

16. A control circuit for transmitting a control signal; the intermediate potential supply unit includes a first short circuit signal line and a second short circuit signal line; the first output control circuit has one end connected to the first terminal of the corresponding transmission driver, and the other end connected to the first short-circuit signal line and the second short-circuit signal line, and is conductive or non-conductive in a direction from the corresponding first terminal to the first short-circuit signal line or the second short-circuit signal line according to the control signal; The sensor controller according to claim 14, wherein the second output control circuit has one end connected to the second terminal of the corresponding transmitting driver and the other end connected to the first short-circuit signal line and the second short-circuit signal line, and is conductive or non-conductive in a direction from the first short-circuit signal line and the second short-circuit signal line to the second terminal of the corresponding transmitting driver according to the control signal.

17. The potential difference between the first potential and the second potential is 5 V or more. The sensor controller according to any one of claims 1 to 16.

18. The touch sensor includes a switch. At least one of the detection electrodes detects depression of the switch. The sensor controller of claim 1 .

19. A touch sensor having a plurality of detection electrodes arranged in a planar shape; a sensor controller including: a plurality of transmission drivers connected to the touch sensor, the transmission drivers having a first terminal to which a first potential is supplied and a second terminal to which a second potential higher than the first potential is supplied, the transmission drivers generating signal waveforms that transition between the first potential and the second potential and outputting the signal waveforms to the corresponding detection electrodes as transmission signals; and an intermediate potential supply unit having a potential generation unit including a voltage source or a capacitive element separate from the transmission drivers, the intermediate potential supply unit supplying an intermediate potential between the first potential and the second potential to at least one of the first terminal and the second terminal by outputting a voltage from the potential generation unit; An electronic device comprising:

20. A touch sensor having a plurality of detection electrodes arranged in a planar shape; a sensor controller connected to the touch sensor, the sensor controller having a first terminal to which a first potential is supplied and a second terminal to which a second potential higher than the first potential is supplied, the sensor controller generating a signal waveform that transitions between the first potential and the second potential and outputting the signal waveform to a corresponding detection electrode as a transmission signal, and an intermediate potential supplying unit that generates an intermediate potential between the first potential and the second potential, supplies the intermediate potential to at least one of the first terminal and the second terminal of at least one of the transmission drivers, and stops supplying the intermediate potential; An electronic device comprising:

21. A method for controlling a sensor controller connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, comprising: generating a signal waveform that transitions between the first potential and the second potential by a plurality of transmission drivers having a first terminal to which a first potential is supplied and a second terminal to which a second potential higher than the first potential is supplied; outputting the signal waveform generated by the transmission driver as a transmission signal to the corresponding detection electrode; outputting an intermediate potential between the first potential and the second potential from a potential generating unit including a voltage source or a capacitive element separate from the transmission driver; supplying the intermediate potential to at least one of the first terminal and the second terminal; A control method for a sensor controller comprising:

22. A method for controlling a sensor controller connected to a touch sensor having a plurality of detection electrodes arranged in a planar shape, comprising: generating a signal waveform that transitions between the first potential and the second potential by a plurality of transmission drivers having a first terminal to which a first potential is supplied and a second terminal to which a second potential higher than the first potential is supplied; outputting the signal waveform generated by the transmission driver as a transmission signal to the corresponding detection electrode; generating an intermediate potential between the first potential and the second potential; supplying the intermediate potential to at least one of the first terminal and the second terminal of at least one of the transmission drivers; Stopping the supply of the intermediate potential; A control method for a sensor controller comprising:

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