WO2020045058A1 - Touch panel - Google Patents

Touch panel Download PDF

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Publication number
WO2020045058A1
WO2020045058A1 PCT/JP2019/031634 JP2019031634W WO2020045058A1 WO 2020045058 A1 WO2020045058 A1 WO 2020045058A1 JP 2019031634 W JP2019031634 W JP 2019031634W WO 2020045058 A1 WO2020045058 A1 WO 2020045058A1
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WO
WIPO (PCT)
Prior art keywords
circuit
detection circuit
touch panel
pressure
detection
Prior art date
Application number
PCT/JP2019/031634
Other languages
French (fr)
Japanese (ja)
Inventor
宏明 北田
Original Assignee
株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Priority to JP2020539310A priority Critical patent/JP6973654B2/en
Priority to CN201990000231.9U priority patent/CN212322228U/en
Publication of WO2020045058A1 publication Critical patent/WO2020045058A1/en

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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means

Definitions

  • the present invention relates to a touch panel that detects a user's touch operation.
  • Patent Document 1 discloses a sensor device that detects a touch operation and a pressing operation on an operation surface.
  • the sensor device of Patent Literature 1 includes a capacitance-type touch panel and a pressure-sensitive sensor. Further, the sensor device of Patent Document 1 includes a second switch circuit. The sensor device of Patent Literature 1 switches the second switch circuit so that the detection circuit for the touch panel doubles as the detection circuit for the pressure-sensitive sensor.
  • Patent Document 1 The pressure-sensitive sensor disclosed in Patent Document 1 is a capacitance-type sensor. Patent Document 1 does not disclose the use of a pressure-sensitive sensor other than the capacitance type.
  • the object of the present invention is to provide a touch panel using a touch sensor and a pressure-sensitive sensor other than a capacitance-type sensor.
  • the touch panel of the present invention includes a touch sensor of a first detection method, a pressure sensor of a second detection method different from the first detection method, a detection circuit connected to the touch sensor and the pressure sensor. And a processing unit connected to the detection circuit.
  • the pressure sensor of the second detection method different from the touch sensor of the first detection method is connected to a processing unit common to the touch sensor (processing unit for the touch sensor).
  • processing unit for the touch sensor processing unit for the touch sensor.
  • the touch panel of the present invention can use the detection circuit for the touch sensor as the detection circuit for the pressure-sensitive sensor.
  • the detection circuit for the touch sensor can be used also as the detection circuit for the pressure-sensitive sensor.
  • FIG. 1 is an external perspective view of a display device 1 including a touch panel.
  • FIG. 2 is a side sectional view of the display device 1.
  • FIG. 3A is a plan view illustrating an example of an electrode arrangement of the touch sensor 20, and
  • FIG. 3B is a plan view illustrating an example of an electrode arrangement of the pressure-sensitive sensor 30.
  • FIG. 4 is a block diagram illustrating a configuration of the touch panel 10 including the touch sensor 20 and the pressure-sensitive sensor 30.
  • FIG. 5 is a circuit diagram showing a configuration example of the charge-voltage conversion circuit 91.
  • FIG. 6 is a circuit diagram showing a modification of the charge-voltage conversion circuit 91.
  • FIG. 7A is a block diagram illustrating a configuration of a touch panel 10B according to Modification Example 1, and FIG.
  • FIG. 7B is a circuit diagram illustrating a partial configuration of a detection circuit 55B.
  • FIG. 8 is a block diagram showing a configuration of a touch panel 10C according to the second modification.
  • FIG. 9 is a circuit diagram showing a modification of the voltage-current conversion circuit 92.
  • FIG. 10 is a circuit diagram showing a partial configuration of a touch panel when using the resistance type pressure-sensitive sensor 30F.
  • FIG. 11 is a block diagram illustrating a configuration of a touch panel 10D according to the third modification.
  • FIG. 12A is a cross-sectional view of a display device 1A including a touch panel 10D
  • FIG. 12B is a plan view of a flexible substrate 300.
  • FIG. 13 is a block diagram showing a configuration of a touch panel 10E according to the fourth modification.
  • FIG. 14 is a block diagram illustrating a configuration of a touch panel 10F according to the fifth modification.
  • FIG. 15 is a plan view showing another example of the electrode arrangement of the pressure-sensitive sensor.
  • FIG. 16 is a block diagram illustrating a configuration of a touch panel 10G including the pressure-sensitive sensor 30C.
  • FIG. 1 is an external perspective view of the display device 1.
  • the width direction (horizontal direction) of the housing 50 is defined as the X direction
  • the length direction (vertical direction) is defined as the Y direction
  • the thickness direction is defined as the Z direction.
  • the display device 1 includes, in appearance, a rectangular parallelepiped casing 50 and a planar surface panel 40 disposed in an opening on the upper surface of the casing 50. I have.
  • the display device 1 is an information processing device such as a smartphone or a tablet terminal.
  • the front panel 40 functions as an operation surface on which a user performs a touch operation using a finger, a pen, or the like.
  • FIG. 2 is a side sectional view of the display device 1. As shown in FIG. 2, inside the housing 50, a surface panel 40, a touch sensor 20, and a pressure-sensitive sensor 30 are sequentially arranged along the Z-axis direction from the opening (surface panel 40) side of the housing 50. Are located.
  • the touch sensor 20, the pressure sensor 30, and the front panel 40 have a flat plate shape.
  • the respective main surfaces of the touch sensor 20, the pressure sensor 30, and the front panel 40 are arranged inside the housing 50 so as to face the main surface of the front panel 40.
  • the main surfaces of the touch sensor 20 and the pressure-sensitive sensor 30 are connected to each other with an adhesive 70.
  • a circuit board 80 is disposed in the housing 50.
  • the circuit board 80 is connected to the touch sensor 20, the pressure-sensitive sensor 30, or the front panel 40 via a flexible cable (not shown).
  • the circuit board 80 may be integrated with the flexible cable using a flexible board material such as a flexible board or may be formed as a part of the main board.
  • the touch sensor 20 is a capacitance-type sensor.
  • the touch sensor 20 includes a first electrode 21, an insulating substrate 22, and a second electrode 23.
  • the insulating substrate 22 is made of a transparent material, for example, PMMA (acrylic resin).
  • the first electrode 21 is arranged on the main surface on the front surface side of the insulating substrate 22, and the second electrode 23 is arranged on the main surface on the back surface side.
  • the first electrode 21 and the second electrode 23 are all made of a material having transparency, for example, a material mainly containing indium tin oxide (ITO), zinc oxide (ZnO), silver nanowires, or polythiophene.
  • ITO indium tin oxide
  • ZnO zinc oxide
  • silver nanowires or polythiophene.
  • FIG. 3A is a plan view illustrating an example of an electrode arrangement of the touch sensor 20.
  • the first electrode 21 has a rectangular shape that is long in one direction in plan view, and is arranged so that the long direction is parallel to the Y direction.
  • the plurality of first electrodes 21 are arranged at predetermined intervals along the X direction.
  • the second electrode 23 has a rectangular shape that is long in one direction in plan view.
  • the second electrode 23 is arranged so that the long direction is parallel to the X direction.
  • the plurality of second electrodes 23 are arranged at predetermined intervals along the Y direction.
  • FIG. 4 is a block diagram illustrating a configuration of the touch panel 10 including the touch sensor 20 and the pressure-sensitive sensor 30.
  • the touch panel 10 includes a touch sensor 20, a pressure sensor 30, and a signal processing circuit 51.
  • the touch panel 10 includes a reference voltage source 90, a charge-voltage conversion circuit 91, and a voltage-current conversion circuit 92.
  • the signal processing circuit 51, the reference voltage source 90, the charge-voltage conversion circuit 91, and the voltage-current conversion circuit 92 are mounted on a circuit board 80.
  • the touch sensor 20 is connected to the signal processing circuit 51.
  • the signal processing circuit 51 includes a plurality of detection circuits 55A, a detection circuit 55B, a signal generation circuit 57, and a processing unit 58.
  • the detection circuit 55A is an example of the “first detection circuit” of the present invention
  • the detection circuit 55B is an example of the “second detection circuit” of the present invention.
  • the detection circuit 55A and the detection circuit 55B are collectively an example of the “detection circuit” of the present invention.
  • the signal generation circuit 57 applies a pulse-shaped voltage signal to the first electrode 21 or the second electrode 23 of the touch sensor 20.
  • the plurality of detection circuits 55A are connected to the first electrode 21 or the second electrode 23 of the touch sensor 20, respectively.
  • the plurality of detection circuits 55A detect the amount of electric charge (current signal) flowing into the detection circuit 55A from the first electrode or the second electrode 23 according to the voltage signal applied by the signal generation circuit 57.
  • the processing unit 58 detects the presence or absence of a touch operation and the touch position based on a change in the current value detected by the detection circuit 55A.
  • the pressure-sensitive sensor 30 includes a first electrode 31, a piezoelectric film 32, and a second electrode 33 in this order from the front panel 40 side.
  • the first electrode 31 and the second electrode 33 are disposed so as to cover substantially the entire main surface of the piezoelectric film 32 as shown in the plan view of FIG.
  • the first electrode 31 is omitted in FIG. 3B, the main surface of the first electrode 31 has the same area as the main surface of the second electrode 33.
  • the first electrode 31 and the second electrode 33 are made of a material having transparency, for example, indium tin oxide (ITO), zinc oxide (ZnO), silver nanowire, or a material mainly containing polythiophene.
  • ITO indium tin oxide
  • ZnO zinc oxide
  • silver nanowire or a material mainly containing polythiophene.
  • the piezoelectric film 32 bends in the normal direction and generates electric charges.
  • the piezoelectric film 32 is made of a transparent material, for example, a chiral polymer. More preferably, the piezoelectric film 32 is made of uniaxially stretched polylactic acid (PLA), and furthermore, L-type polylactic acid (PLLA).
  • the chiral polymer has a helical structure in the main chain, and has piezoelectricity when the molecule is uniaxially stretched and oriented.
  • the amount of charge generated by the uniaxially stretched chiral polymer is uniquely determined by the shear strain applied along the molecular axis of the helical molecule.
  • the uniaxially stretched PLLA has a very high piezoelectric constant in polymers. That is, the pressing operation can be detected with high sensitivity, and the electric charge corresponding to the pressing amount can be output with high accuracy.
  • chiral polymers do not need to be subjected to a poling treatment because piezoelectricity is generated by molecular orientation treatment by stretching or the like.
  • polylactic acid since polylactic acid has no pyroelectricity, the amount of generated electric charge does not change even when heat from a user's finger or the like is transmitted.
  • there is no influence such as a change in pressure sensitivity due to heat generation of the device or an ambient environment temperature.
  • it is effective to use polylactic acid for a small electronic device such as a smartphone or a tablet terminal in which a battery that easily generates heat and a piezoelectric film are arranged close to each other.
  • the piezoelectric constant of polylactic acid does not fluctuate with time and is extremely stable.
  • the piezoelectric film 32 expands or contracts in the horizontal direction.
  • spiral molecules contributing to piezoelectricity are oriented in the stretching axis direction.
  • the piezoelectric film 32 is arranged such that the uniaxial stretching direction forms an angle of approximately 45 ° with respect to the X direction and the Y direction.
  • the stretching ratio is preferably about 3 to 8 times.
  • the same effect as uniaxial stretching can be obtained by making the stretching ratio of each axis different. For example, when stretching is performed eight times in the X-axis direction and two times in the Y-axis direction orthogonal to the X-axis with a certain direction as the X-axis, uniaxial stretching is performed about four times in the X-axis direction with respect to the piezoelectric constant. The same effect as in the case can be obtained. Since a uniaxially stretched film is easily torn along the stretching axis direction, the strength can be increased somewhat by performing the biaxial stretching as described above.
  • a reference voltage source 90 and a charge-voltage conversion circuit 91 are connected to the pressure-sensitive sensor 30.
  • the reference voltage source 90 applies a reference voltage to the first electrode 31 or the second electrode 33 of the pressure sensor 30.
  • the charge-voltage conversion circuit 91 is connected to the first electrode 31 or the second electrode 33, and converts a charge generated in the piezoelectric film 32 into a voltage.
  • FIG. 5 is a circuit diagram showing a configuration example of the charge-voltage conversion circuit 91.
  • the charge-voltage conversion circuit 91 includes an operational amplifier A, a resistor R, and a capacitor C.
  • the inverting input terminal of the operational amplifier A is connected to the first electrode 31 or the second electrode 33.
  • the non-inverting input terminal of the operational amplifier A is connected to the reference voltage source 90.
  • An output terminal of the operational amplifier A is feedback-connected to an inverting input terminal of the operational amplifier A via a parallel circuit of a resistor R and a capacitor C.
  • the charge-voltage conversion circuit 91 forms an integration circuit, and converts charges generated in the piezoelectric film 32 into a voltage.
  • the voltage / current conversion circuit 92 converts the voltage signal output from the charge / voltage conversion circuit 91 into a current signal.
  • the charge-voltage conversion circuit 91 is composed of, for example, a resistor. Therefore, a current signal corresponding to the electric charge generated in the piezoelectric film 32 is input to the detection circuit 55B in the signal processing circuit 51.
  • the plurality of detection circuits 55A and 55B are detection circuits for a capacitive touch sensor. That is, the detection circuit 55A and the detection circuit 55B are the same type of circuit (current detection circuit in this embodiment), and both are connected to the common processing unit 58.
  • the processing unit 58 detects the presence or absence of a touch operation and the touch position according to the current value detected by the detection circuit 55A. Further, the processing unit 58 detects the presence or absence of a pressing operation and the amount of pressing according to the current value detected by the detection circuit 55B.
  • the capacitive touch sensor inputs a voltage signal for detection.
  • electric charges are continuously generated by a detection voltage signal, and thus a current signal is input to the detection circuit.
  • the detection circuit for the capacitive touch sensor is adjusted to have a sensitivity for detecting the current signal.
  • the pressure-sensitive sensor generates an electric charge intermittently when the user presses it. Therefore, the amount of electric charge (current value) flowing into the detection circuit differs greatly between the capacitive touch sensor and the pressure-sensitive sensor.
  • the pressure-sensitive sensor 30 of the present embodiment is connected to the detection circuit 55B via the charge-voltage conversion circuit 91 and the voltage-current conversion circuit 92.
  • the touch panel of the present embodiment uses the detection circuits for the capacitive touch sensor (the detection circuit 55A as the first detection circuit and the detection circuit 55B as the second detection circuit) as the detection circuits for the pressure-sensitive sensor. It can be shared.
  • FIG. 6 is a circuit diagram showing a modification of the charge-voltage conversion circuit 91.
  • 6 includes an operational amplifier A, resistors R1, R2, R3, and a capacitor C.
  • the inverting input terminal of the operational amplifier A is connected to the first electrode 31 or the second electrode 33.
  • the non-inverting input terminal of the operational amplifier A is connected to the input terminal of the charge-voltage conversion circuit 91 and the reference voltage source 90.
  • the non-inverting input terminal is connected to a reference voltage source 90 via a parallel circuit of a resistor R1 and a capacitor C.
  • the inverting input terminal of the operational amplifier A is connected to the reference voltage source 90 via the resistor R2.
  • the output terminal of the operational amplifier A is feedback-connected to the inverting input terminal of the operational amplifier A via the resistor R3.
  • the charge-voltage conversion circuit 91 forms an integration circuit, and converts the charge generated in the piezoelectric film 32 into a voltage. Further, the charge-voltage conversion circuit 91 shown in FIG. 6 has a gain according to the ratio between the feedback resistor R3 and the resistor R2, and thus constitutes an amplifier circuit. Therefore, the charge-voltage conversion circuit 91 shown in FIG. 6 can increase the sensitivity of the pressure-sensitive sensor 30.
  • FIG. 7A is a block diagram illustrating a configuration of a touch panel 10B according to the first modification.
  • FIG. 7B is a circuit diagram illustrating a partial configuration of the detection circuit 55B. Since the detection circuits 55A and 55B have the same configuration as described above, FIG. 7B shows the configuration of the detection circuit 55B as a representative.
  • the touch panel 10B is different from the touch panel 10 shown in FIG. 4 in that the voltage-current conversion circuit 92 is omitted. 7B, the detection circuit 55B includes at least a sample and hold circuit 550, an ADC (AD converter) 551, and an initialization circuit 552.
  • the detection circuit 55B includes at least a sample and hold circuit 550, an ADC (AD converter) 551, and an initialization circuit 552.
  • touch panel 10B Other configurations of the touch panel 10B are the same as those of the touch panel 10 shown in FIG.
  • the same components as those of the touch panel 10 of FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.
  • the detection circuit 55B is connected to the initialization circuit 552 and the capacitor of the sample and hold circuit 550 at each measurement timing of the touch sensor 20, and the capacitor of the sample and hold circuit 550 is initialized. Thereafter, the connection between the sample hold circuit 550 and the initialization circuit 552 is released, and the sample hold circuit 550 is connected to the charge-voltage conversion circuit 91. Further, the sample hold circuit 550 and the ADC 551 are connected. The voltage signal output from the charge-voltage conversion circuit 91 is held by the sample hold circuit 550. The ADC 551 converts the held voltage signal into a digital signal.
  • the pressure-sensitive sensor 30 can be connected to the detection circuit 55B, which is a current detection circuit.
  • FIG. 8 is a block diagram illustrating a configuration of a touch panel 10C according to the second modification.
  • the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
  • the voltage-current conversion circuit 92 and the detection circuit 55C are connected to the ground via a capacitor.
  • the detection circuit 55C is connected to the signal generation circuit 57.
  • the detection circuit 55C is a detection circuit of a self-capacitive touch sensor.
  • the detection circuit 55C is an example of the “second detection circuit” of the present invention.
  • An information processing device such as a smartphone may include a mutual capacitance type detection circuit and a self-capacitance type detection circuit, as in the example of FIG.
  • the pressure-sensitive sensor 30 can be connected to the self-capacitance detection circuit 55C instead of the mutual capacitance detection circuit 55A and the detection circuit 55B.
  • FIG. 9 is a circuit diagram showing a modified example of the voltage-current conversion circuit 92.
  • the voltage-current conversion circuit 92 in this modification includes operational amplifiers A1 and A2 and resistors R1, R2, R3, R4, and R5.
  • the inverting input terminal of the operational amplifier A1 is connected to the reference voltage source 90 via the resistor R1.
  • the non-inverting input terminal of the operational amplifier A1 is connected to the first electrode 31 or the second electrode 33 via the resistor R3.
  • the output terminal of the operational amplifier A1 is feedback-connected to the inverting input terminal of the operational amplifier A1 via the resistor R2.
  • the output terminal of the operational amplifier A1 is connected via a resistor R5 to the output terminal and the non-inverting input terminal of the operational amplifier A2.
  • the output terminal of the operational amplifier A2 is feedback-connected to the inverting input terminal. Further, the output terminal of the operational amplifier A2 is feedback-connected to the non-inverting input terminal of the operational amplifier A1 via the resistor R4.
  • the operational amplifier A1 is a non-inverting amplifier circuit whose gain is determined by the ratio of the resistors R1 and R2.
  • the operational amplifier A2 forms a voltage follower. When the load resistance at the subsequent stage is low, the operational amplifier A2 may be omitted.
  • the voltage-current conversion circuit 92 outputs a current value according to the input voltage value.
  • the output current value is determined by the ratio of the resistors R3, R4, R5. According to such a configuration, the linearity of the current signal with respect to the voltage signal is higher than that of the voltage-current conversion circuit 92 including only the resistor.
  • FIG. 10 is a circuit diagram showing a partial configuration of the touch panel in the case of using the resistance type pressure-sensitive sensor 30F.
  • the pressure-sensitive sensor 30F shown in FIG. 10 includes a bridge circuit including a plurality of resistors.
  • the output of the pressure-sensitive sensor 30F is connected to the amplifier circuit 95.
  • the pressure-sensitive sensor 30F is distorted, and the value of each resistor constituting the bridge circuit changes. Therefore, a potential difference is generated between both input terminals of the operational amplifier included in the amplification circuit 95, and a voltage signal is output to the voltage-current conversion circuit 92.
  • the pressure-sensitive sensor of the present invention is not limited to the piezoelectric type, but may be a resistance type.
  • FIG. 11 is a block diagram illustrating a configuration of a touch panel 10D according to the third modification.
  • the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
  • FIG. 12A is a cross-sectional view of a display device 1A including a touch panel 10D.
  • the display device 1A includes the second pressure-sensitive sensor 30B and the flexible substrate 300.
  • the second pressure sensor 30B is smaller than the pressure sensor 30.
  • the second pressure-sensitive sensor 30 ⁇ / b> B is arranged on the inner wall on the side surface of the housing 50.
  • the second pressure-sensitive sensor 30B is provided to detect an operation of pressing the side of the user instead of a physical switch such as a power button or a volume button.
  • the second pressure sensor 30B is connected to the reference voltage source 90 and the charge-voltage conversion circuit 91 of the circuit board 80 via the flexible board 300.
  • FIG. 12B is a plan view of the flexible substrate 300.
  • the flexible substrate 300 is made of, for example, a resin base material and has flexibility.
  • the flexible substrate 300 has a meandering shape.
  • the conductor pattern 301 is formed on the main surface or inside of the flexible substrate 300 along the shape of the flexible substrate 300.
  • the circuit board 80 is arranged at a position close to the capacitance type sensor. However, as in the example of FIG. 12A, the circuit board 80 may be arranged at a position far from the capacitance type sensor. Since the present invention is characterized in that the pressure-sensitive sensor is connected to the detection circuit of the capacitance-type sensor, from the pressure-sensitive sensor disposed far from the circuit board 80 to the circuit of the capacitance-type sensor Wiring needs to be routed. In such a case, the circuit board 80 is often arranged on the display module side, and the pressure-sensitive sensor is often arranged on the main body side. The display module is attached to the main body from above at the end of the assembly process. The pressure sensor and the circuit board must be connected before bonding.
  • the flexible substrate 300 has a meandering shape. Therefore, the flexible substrate 300 can be stretched to some extent without being damaged. Thus, even when the second pressure-sensitive sensor 30B is installed at a position distant from the circuit board 80, the flexible substrate 300 can be easily attached at the time of manufacturing, and the above-described problem can be solved.
  • FIG. 13 is a block diagram showing a configuration of a touch panel 10E according to the fourth modification.
  • the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
  • the reference voltage source 90 is built in the signal processing circuit 51. That is, the reference voltage source 90 is a reference voltage source for a touch sensor. In touch panel 10E of Modification 4, the reference voltage source for the touch sensor is also used as the reference voltage source for the pressure-sensitive sensor. Accordingly, it is not necessary to separately prepare a reference voltage source for the pressure-sensitive sensor, and the cost can be reduced. In addition, since all the reference potentials in the touch panel 10E are common and there is no difference in the reference potentials, the usable voltage range can be increased. Further, by incorporating the reference voltage source 90 in the signal processing circuit 51, a reference voltage that is not easily affected by power supply voltage fluctuation, such as a band gap type reference voltage source, can be used as the reference voltage source. For this reason, the power-supply voltage fluctuation suppression performance of the pressure-sensitive sensor 30 is improved.
  • a reference voltage that is not easily affected by power supply voltage fluctuation such as a band gap type reference voltage source
  • FIG. 14 is a block diagram illustrating a configuration of a touch panel 10F according to Modification 5.
  • the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
  • the touch panel 10F includes a switch circuit 920.
  • the switch circuit 920 is connected to the detection circuit 55A, the touch sensor 20, and the voltage-current conversion circuit 92.
  • the touch panel 10F switches the switch circuit 920 to connect the touch sensor 20 or the voltage-current conversion circuit 92 to the detection circuit 55A.
  • the detection circuit 55A of the touch sensor 20 is also used as a detection circuit for the pressure-sensitive sensor 30.
  • FIG. 15 is a plan view showing another example of the electrode arrangement of the pressure-sensitive sensor.
  • the electrode for detecting electric charge is divided into a second electrode 33A and a second electrode 33B.
  • the first electrode 31 (not shown) is disposed so as to cover substantially the entire main surface of the piezoelectric film 32.
  • the second electrode 33A and the second electrode 33B are respectively connected to different circuits.
  • FIG. 16 is a block diagram illustrating a configuration of a touch panel 10G including the pressure-sensitive sensor 30C.
  • the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
  • the pressure-sensitive sensor 30C is connected to two charge-voltage conversion circuits 91, respectively.
  • the second electrode 33A and the second electrode 33B are connected to different charge-voltage conversion circuits 91, respectively.
  • the processing unit 58 can detect the pressed position by determining whether the pressing operation has been performed on each of the second electrode 33A and the second electrode 33B. For example, when the detection circuit 55B connected to the second electrode 33A detects a pressing operation, the processing unit 58 can determine that the pressing operation has been performed at the left position in plan view.
  • the same configuration and function can be exhibited by dividing the electrode of one pressure-sensitive sensor into a plurality of pressure-sensitive sensors instead of dividing the electrode.
  • the processing unit 58 can detect operation patterns equal to or more than the total number of the detection circuits (the first detection circuit and the second detection circuit). For example, the processing unit 58 repeats a pattern in which pressing is performed only once within a predetermined time (one tap pattern), a pattern in which pressing is continued for a predetermined time or more (long pressing pattern), or pressing twice in a predetermined time. A pressing operation such as a pattern (double tap pattern) is detected as different operation patterns. Alternatively, the processing unit 58 may detect a different operation pattern according to the amount of pressing. As described above, the processing unit 58 can detect a plurality of operation patterns for one detection circuit.
  • A, A1, A2 ... operational amplifier C ... capacitors R, R1, R2, R3, R4, R5 ... resistor 1 ... display devices 10, 10B, 10C, 10D, 10E, 10F, 10G ... touch panel 20 ... touch sensor 21 ...
  • First Electrode 22 Insulating substrate 23 Second electrode 30, 30F Pressure sensor 30B Second pressure sensor 30C Pressure sensor 31 First electrode 32 Piezoelectric films 33, 33A, 33B Second electrode 40 Front panel 50 Casing 51 Signal processing circuits 55A, 55B, 55C Detection circuit 57 Signal generation circuit 58 Processing unit 70 Adhesive 80 Circuit board 90 Reference voltage source 91 Charge voltage conversion circuit 92 Voltage Current conversion circuit 95 amplifier circuit 300 flexible substrate 301 conductor pattern 550 sample hold circuit 551 ADC 552: initialization circuit 920: switch circuit

Abstract

This touch panel is characterized by comprising: a touch sensor (20) that uses a first detection method; a pressure-sensitive sensor (30) that uses a second detection method which is different from the first detection method; detection circuits (55A, 55B) that are connected to the touch sensor (20); and a processing unit (58) that is connected to the detection circuits (55A, 55B).

Description

タッチパネルTouch panel
　本発明は、利用者のタッチ操作を検出するタッチパネルに関する。 The present invention relates to a touch panel that detects a user's touch operation.
　特許文献１には、操作面に対するタッチ操作と、押圧操作と、を検知するセンサ装置が開示されている。特許文献１のセンサ装置は、静電容量式のタッチパネルおよび感圧センサを備えている。また、特許文献１のセンサ装置は、第２のスイッチ回路を備えている。特許文献１のセンサ装置は、第２のスイッチ回路を切り替えることで、タッチパネル用の検出回路を感圧センサ用の検出回路として兼用する。 Patent Document 1 discloses a sensor device that detects a touch operation and a pressing operation on an operation surface. The sensor device of Patent Literature 1 includes a capacitance-type touch panel and a pressure-sensitive sensor. Further, the sensor device of Patent Document 1 includes a second switch circuit. The sensor device of Patent Literature 1 switches the second switch circuit so that the detection circuit for the touch panel doubles as the detection circuit for the pressure-sensitive sensor.
特開２０１１－１３４０００号公報JP 2011-134000 A
　特許文献１に開示された感圧センサは、静電容量式のセンサである。特許文献１には、静電容量式以外の感圧センサを用いることについて何ら記載されていない。 圧 The pressure-sensitive sensor disclosed in Patent Document 1 is a capacitance-type sensor. Patent Document 1 does not disclose the use of a pressure-sensitive sensor other than the capacitance type.
　本発明は、タッチセンサと、静電容量式のセンサ以外の感圧センサと、を用いたタッチパネルを提供することを目的とする。 The object of the present invention is to provide a touch panel using a touch sensor and a pressure-sensitive sensor other than a capacitance-type sensor.
　本発明のタッチパネルは、第１の検出方式のタッチセンサと、第１の検出方式とは異なる第２の検出方式の感圧センサと、前記タッチセンサおよび前記感圧センサに接続される検出回路と、前記検出回路に接続される処理部と、を備えたことを特徴とする。 The touch panel of the present invention includes a touch sensor of a first detection method, a pressure sensor of a second detection method different from the first detection method, a detection circuit connected to the touch sensor and the pressure sensor. And a processing unit connected to the detection circuit.
　この様に、本発明のタッチパネルは、第１の検出方式のタッチセンサとは異なる第２の検出方式の感圧センサを、タッチセンサと共通の処理部（タッチセンサ用の処理部）に接続する。これにより、本発明のタッチパネルは、タッチセンサ用の検出回路を感圧センサ用の検出回路として兼用することができる。 As described above, in the touch panel of the present invention, the pressure sensor of the second detection method different from the touch sensor of the first detection method is connected to a processing unit common to the touch sensor (processing unit for the touch sensor). . Thus, the touch panel of the present invention can use the detection circuit for the touch sensor as the detection circuit for the pressure-sensitive sensor.
　この発明によれば、タッチセンサ用の検出回路を感圧センサ用の検出回路として兼用することができる。 According to the present invention, the detection circuit for the touch sensor can be used also as the detection circuit for the pressure-sensitive sensor.
図１は、タッチパネルを備えた表示装置１の外観斜視図である。FIG. 1 is an external perspective view of a display device 1 including a touch panel. 図２は、表示装置１の側面断面図である。FIG. 2 is a side sectional view of the display device 1. 図３（Ａ）は、タッチセンサ２０の電極配置の一例を示す平面図であり、図３（Ｂ）は、感圧センサ３０の電極配置の一例を示す平面図である。FIG. 3A is a plan view illustrating an example of an electrode arrangement of the touch sensor 20, and FIG. 3B is a plan view illustrating an example of an electrode arrangement of the pressure-sensitive sensor 30. 図４は、タッチセンサ２０および感圧センサ３０を備えたタッチパネル１０の構成を示すブロック図である。FIG. 4 is a block diagram illustrating a configuration of the touch panel 10 including the touch sensor 20 and the pressure-sensitive sensor 30. 図５は、電荷電圧変換回路９１の構成例を示す回路図である。FIG. 5 is a circuit diagram showing a configuration example of the charge-voltage conversion circuit 91. 図６は、電荷電圧変換回路９１の変形例を示す回路図である。FIG. 6 is a circuit diagram showing a modification of the charge-voltage conversion circuit 91. 図７（Ａ）は、変形例１に係るタッチパネル１０Ｂの構成を示すブロック図であり、図７（Ｂ）は、検出回路５５Ｂの一部構成を示す回路図である。FIG. 7A is a block diagram illustrating a configuration of a touch panel 10B according to Modification Example 1, and FIG. 7B is a circuit diagram illustrating a partial configuration of a detection circuit 55B. 図８は、変形例２に係るタッチパネル１０Ｃの構成を示すブロック図である。FIG. 8 is a block diagram showing a configuration of a touch panel 10C according to the second modification. 図９は、電圧電流変換回路９２の変形例を示す回路図である。FIG. 9 is a circuit diagram showing a modification of the voltage-current conversion circuit 92. 図１０は、抵抗式の感圧センサ３０Ｆを用いる場合のタッチパネルの一部構成を示す回路図である。FIG. 10 is a circuit diagram showing a partial configuration of a touch panel when using the resistance type pressure-sensitive sensor 30F. 図１１は、変形例３に係るタッチパネル１０Ｄの構成を示すブロック図である。FIG. 11 is a block diagram illustrating a configuration of a touch panel 10D according to the third modification. 図１２（Ａ）は、タッチパネル１０Ｄを備えた表示装置１Ａの断面図であり、図１２（Ｂ）は、フレキシブル基板３００の平面図である。FIG. 12A is a cross-sectional view of a display device 1A including a touch panel 10D, and FIG. 12B is a plan view of a flexible substrate 300. 図１３は、変形例４に係るタッチパネル１０Ｅの構成を示すブロック図である。FIG. 13 is a block diagram showing a configuration of a touch panel 10E according to the fourth modification. 図１４は、変形例５に係るタッチパネル１０Ｆの構成を示すブロック図である。FIG. 14 is a block diagram illustrating a configuration of a touch panel 10F according to the fifth modification. 図１５は、感圧センサの電極配置の他の例を示す平面図である。FIG. 15 is a plan view showing another example of the electrode arrangement of the pressure-sensitive sensor. 図１６は、感圧センサ３０Ｃを備えたタッチパネル１０Ｇの構成を示すブロック図である。FIG. 16 is a block diagram illustrating a configuration of a touch panel 10G including the pressure-sensitive sensor 30C.
　以下、図面を参照して、本発明のタッチパネルを備えた表示装置１について説明する。図１は、表示装置１の外観斜視図である。本実施形態では、筐体５０の幅方向（横方向）をＸ方向とし、長さ方向（縦方向）をＹ方向とし、厚み方向をＺ方向とする。 Hereinafter, the display device 1 including the touch panel of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of the display device 1. In the present embodiment, the width direction (horizontal direction) of the housing 50 is defined as the X direction, the length direction (vertical direction) is defined as the Y direction, and the thickness direction is defined as the Z direction.
　図１の外観斜視図に示すように、表示装置１は、外観上、直方体形状の筐体５０と、筐体５０の上面の開口部に配置された平面状の表面パネル４０と、を備えている。表示装置１は、例えばスマートフォンまたはタブレット端末等の情報処理装置である。表面パネル４０は、利用者が指またはペン等を用いてタッチ操作を行う操作面として機能する。 As shown in the external perspective view of FIG. 1, the display device 1 includes, in appearance, a rectangular parallelepiped casing 50 and a planar surface panel 40 disposed in an opening on the upper surface of the casing 50. I have. The display device 1 is an information processing device such as a smartphone or a tablet terminal. The front panel 40 functions as an operation surface on which a user performs a touch operation using a finger, a pen, or the like.
　図２は、表示装置１の側面断面図である。図２に示すように、筐体５０の内部には、筐体５０の開口部（表面パネル４０）側から順にＺ軸方向に沿って、表面パネル４０、タッチセンサ２０、および感圧センサ３０が配置されている。 FIG. 2 is a side sectional view of the display device 1. As shown in FIG. 2, inside the housing 50, a surface panel 40, a touch sensor 20, and a pressure-sensitive sensor 30 are sequentially arranged along the Z-axis direction from the opening (surface panel 40) side of the housing 50. Are located.
　タッチセンサ２０、感圧センサ３０、および表面パネル４０は、平板状の形状である。タッチセンサ２０、感圧センサ３０、および表面パネル４０のそれぞれの主面は、表面パネル４０の主面と対向するように、筐体５０の内部に配置されている。タッチセンサ２０および感圧センサ３０の主面は、粘着剤７０で互いに接続されている。 The touch sensor 20, the pressure sensor 30, and the front panel 40 have a flat plate shape. The respective main surfaces of the touch sensor 20, the pressure sensor 30, and the front panel 40 are arranged inside the housing 50 so as to face the main surface of the front panel 40. The main surfaces of the touch sensor 20 and the pressure-sensitive sensor 30 are connected to each other with an adhesive 70.
　筐体５０には、回路基板８０が配置されている。回路基板８０は、不図示のフレキシブルケーブルを介して、タッチセンサ２０、感圧センサ３０、または表面パネル４０に接続される。回路基板８０は、フレキシブル基板等の屈曲可能な基板材料を用いて、上記フレキシブルケーブルと一体化してもよいし、メイン基板の一部として形成してもよい。 回路 A circuit board 80 is disposed in the housing 50. The circuit board 80 is connected to the touch sensor 20, the pressure-sensitive sensor 30, or the front panel 40 via a flexible cable (not shown). The circuit board 80 may be integrated with the flexible cable using a flexible board material such as a flexible board or may be formed as a part of the main board.
　タッチセンサ２０は、静電容量式のセンサである。タッチセンサ２０は、第１電極２１、絶縁性基板２２、および第２電極２３を備えている。絶縁性基板２２は、透明性を有する材料からなり、例えばＰＭＭＡ（アクリル樹脂）からなる。絶縁性基板２２の表面側の主面には、第１電極２１が配置され、裏面側の主面には、第２電極２３が配置されている。 The touch sensor 20 is a capacitance-type sensor. The touch sensor 20 includes a first electrode 21, an insulating substrate 22, and a second electrode 23. The insulating substrate 22 is made of a transparent material, for example, PMMA (acrylic resin). The first electrode 21 is arranged on the main surface on the front surface side of the insulating substrate 22, and the second electrode 23 is arranged on the main surface on the back surface side.
　第１電極２１および第２電極２３は、全て透明性を有する材料からなり、例えば酸化インジウムスズ（ＩＴＯ）、酸化亜鉛（ＺｎＯ）、銀ナノワイヤー、またはポリチオフェンを主成分とする材料からなる。 The first electrode 21 and the second electrode 23 are all made of a material having transparency, for example, a material mainly containing indium tin oxide (ITO), zinc oxide (ZnO), silver nanowires, or polythiophene.
　図３（Ａ）は、タッチセンサ２０の電極配置の一例を示す平面図である。第１電極２１は、平面視して一方向に長い長方形状であり、長尺方向がＹ方向に平行になるように配置されている。複数の第１電極２１は、Ｘ方向に沿って所定の間隔で配置されている。 FIG. 3A is a plan view illustrating an example of an electrode arrangement of the touch sensor 20. The first electrode 21 has a rectangular shape that is long in one direction in plan view, and is arranged so that the long direction is parallel to the Y direction. The plurality of first electrodes 21 are arranged at predetermined intervals along the X direction.
　また、第２電極２３も、平面視して一方向に長い長方形状である。第２電極２３は、長尺方向がＸ方向に平行になるように配置されている。複数の第２電極２３は、Ｙ方向に沿って所定の間隔で配置されている。 {Circle around (2)} Also, the second electrode 23 has a rectangular shape that is long in one direction in plan view. The second electrode 23 is arranged so that the long direction is parallel to the X direction. The plurality of second electrodes 23 are arranged at predetermined intervals along the Y direction.
　図４は、タッチセンサ２０および感圧センサ３０を備えたタッチパネル１０の構成を示すブロック図である。タッチパネル１０は、タッチセンサ２０、感圧センサ３０、および信号処理回路５１を備えている。また、この例では、タッチパネル１０は、基準電圧源９０、電荷電圧変換回路９１、および電圧電流変換回路９２を備えている。信号処理回路５１、基準電圧源９０、電荷電圧変換回路９１、および電圧電流変換回路９２は、回路基板８０に搭載されている。 FIG. 4 is a block diagram illustrating a configuration of the touch panel 10 including the touch sensor 20 and the pressure-sensitive sensor 30. The touch panel 10 includes a touch sensor 20, a pressure sensor 30, and a signal processing circuit 51. In this example, the touch panel 10 includes a reference voltage source 90, a charge-voltage conversion circuit 91, and a voltage-current conversion circuit 92. The signal processing circuit 51, the reference voltage source 90, the charge-voltage conversion circuit 91, and the voltage-current conversion circuit 92 are mounted on a circuit board 80.
　タッチセンサ２０は、信号処理回路５１に接続される。信号処理回路５１は、複数の検出回路５５Ａ、検出回路５５Ｂ、信号生成回路５７、および処理部５８を備えている。なお、検出回路５５Ａは、本発明の「第１検出回路」の一例であり、検出回路５５Ｂは、本発明の「第２検出回路」の一例である。また、検出回路５５Ａ及び検出回路５５Ｂは、一まとまりとして、本発明の「検出回路」の一例である。 (4) The touch sensor 20 is connected to the signal processing circuit 51. The signal processing circuit 51 includes a plurality of detection circuits 55A, a detection circuit 55B, a signal generation circuit 57, and a processing unit 58. The detection circuit 55A is an example of the “first detection circuit” of the present invention, and the detection circuit 55B is an example of the “second detection circuit” of the present invention. The detection circuit 55A and the detection circuit 55B are collectively an example of the “detection circuit” of the present invention.
　信号生成回路５７は、タッチセンサ２０の第１電極２１または第２電極２３にパルス状の電圧信号を印加する。複数の検出回路５５Ａは、それぞれタッチセンサ２０の第１電極２１または第２電極２３に接続されている。複数の検出回路５５Ａは、信号生成回路５７により印加された電圧信号に応じて、第１電極または第２電極２３から検出回路５５Ａに流入する電荷量（電流信号）を検出する。 The signal generation circuit 57 applies a pulse-shaped voltage signal to the first electrode 21 or the second electrode 23 of the touch sensor 20. The plurality of detection circuits 55A are connected to the first electrode 21 or the second electrode 23 of the touch sensor 20, respectively. The plurality of detection circuits 55A detect the amount of electric charge (current signal) flowing into the detection circuit 55A from the first electrode or the second electrode 23 according to the voltage signal applied by the signal generation circuit 57.
　利用者が指またはペン等を用いて表面パネル４０に対しタッチ操作を行うと、第１電極２１および第２電極２３に生じた電荷の一部が利用者の指またはペンに流入する。したがって、検出回路５５Ａに流入する電荷量（電流値）が減少する。処理部５８は、検出回路５５Ａで検出される電流値の変化に基づいて、タッチ操作の有無およびタッチ位置を検出する。 (4) When the user performs a touch operation on the front panel 40 using a finger or a pen or the like, a part of the charges generated on the first electrode 21 and the second electrode 23 flows into the user's finger or pen. Therefore, the amount of charge (current value) flowing into the detection circuit 55A decreases. The processing unit 58 detects the presence or absence of a touch operation and the touch position based on a change in the current value detected by the detection circuit 55A.
　図２に戻り、感圧センサ３０は、表面パネル４０側から順に、第１電極３１、圧電フィルム３２、および第２電極３３を備えている。第１電極３１および第２電極３３は、図３（Ｂ）の平面図に示す様に、圧電フィルム３２の主面の略全面を覆うように配置されている。図３（Ｂ）において第１電極３１は省略しているが、第１電極３１の主面は、第２電極３３の主面と同じ面積を有する。 2, the pressure-sensitive sensor 30 includes a first electrode 31, a piezoelectric film 32, and a second electrode 33 in this order from the front panel 40 side. The first electrode 31 and the second electrode 33 are disposed so as to cover substantially the entire main surface of the piezoelectric film 32 as shown in the plan view of FIG. Although the first electrode 31 is omitted in FIG. 3B, the main surface of the first electrode 31 has the same area as the main surface of the second electrode 33.
　第１電極３１および第２電極３３は、透明性を有する材料からなり、例えば酸化インジウムスズ（ＩＴＯ）、酸化亜鉛（ＺｎＯ）、銀ナノワイヤー、またはポリチオフェンを主成分とする材料からなる。 The first electrode 31 and the second electrode 33 are made of a material having transparency, for example, indium tin oxide (ITO), zinc oxide (ZnO), silver nanowire, or a material mainly containing polythiophene.
　圧電フィルム３２は、利用者が表面パネル４０を押圧することで法線方向に撓み、電荷を発生する。圧電フィルム３２は、透明性を有する材料からなり、例えばキラル高分子からなる。より好ましくは、圧電フィルム３２には、一軸延伸されたポリ乳酸（ＰＬＡ）、さらにはＬ型ポリ乳酸（ＰＬＬＡ）である。 (4) When the user presses the front panel 40, the piezoelectric film 32 bends in the normal direction and generates electric charges. The piezoelectric film 32 is made of a transparent material, for example, a chiral polymer. More preferably, the piezoelectric film 32 is made of uniaxially stretched polylactic acid (PLA), and furthermore, L-type polylactic acid (PLLA).
　キラル高分子は、主鎖が螺旋構造を有し、一軸延伸されて分子が配向すると、圧電性を有する。そして、一軸延伸されたキラル高分子が発生する電荷量は、螺旋分子の分子軸に沿って加わったずり歪みによって一意的に決定される。 The chiral polymer has a helical structure in the main chain, and has piezoelectricity when the molecule is uniaxially stretched and oriented. The amount of charge generated by the uniaxially stretched chiral polymer is uniquely determined by the shear strain applied along the molecular axis of the helical molecule.
　一軸延伸されたＰＬＬＡの圧電定数は、高分子中で非常に高い部類に属する。すなわち、押圧操作を高感度に検出し、押圧量に応じた電荷を高精度に出力することができる。 圧 電 The uniaxially stretched PLLA has a very high piezoelectric constant in polymers. That is, the pressing operation can be detected with high sensitivity, and the electric charge corresponding to the pressing amount can be output with high accuracy.
　また、キラル高分子は、延伸等による分子の配向処理で圧電性が生じるため、ポーリング処理を行う必要がない。特に、ポリ乳酸は、焦電性がないため、利用者の指等の熱が伝わる場合であっても、発生する電荷量が変化することがない。また、機器の発熱や周囲環境温度によって押圧感度が変わる等の影響を受けることもない。特に、ポリ乳酸は、発熱し易いバッテリと圧電フィルムとを近接配置するようなスマートフォンまたはタブレット端末等の小型電子機器に対して用いることが有効である。さらに、ポリ乳酸の圧電定数は経時的に変動することがなく、極めて安定している。 In addition, chiral polymers do not need to be subjected to a poling treatment because piezoelectricity is generated by molecular orientation treatment by stretching or the like. In particular, since polylactic acid has no pyroelectricity, the amount of generated electric charge does not change even when heat from a user's finger or the like is transmitted. In addition, there is no influence such as a change in pressure sensitivity due to heat generation of the device or an ambient environment temperature. In particular, it is effective to use polylactic acid for a small electronic device such as a smartphone or a tablet terminal in which a battery that easily generates heat and a piezoelectric film are arranged close to each other. Furthermore, the piezoelectric constant of polylactic acid does not fluctuate with time and is extremely stable.
　表面パネル４０が利用者に押下されたとき、圧電フィルム３２は、水平方向に伸びる、または収縮する。押下操作による伸縮は、螺旋分子の分子軸に対してずり歪みとなるように分子軸を配置することが望ましい。一軸延伸のポリ乳酸フィルムでは、圧電性に寄与する螺旋分子は延伸軸方向に向いている。本実施形態では、圧電フィルム３２は、Ｘ方向およびＹ方向に対して、一軸延伸方向が略４５°の角度を成すように配置されている。このような配置を行うことで、より高感度に押圧操作を検出できる。なお、一軸延伸方向は、４５°であることが最も効果的であるが、例えば４５±１０°の範囲であっても略同等の効果が得られる。 (4) When the front panel 40 is pressed by the user, the piezoelectric film 32 expands or contracts in the horizontal direction. For the expansion and contraction by the pressing operation, it is desirable to arrange the molecular axes so that the molecular axes of the helical molecules are sheared. In a uniaxially stretched polylactic acid film, spiral molecules contributing to piezoelectricity are oriented in the stretching axis direction. In the present embodiment, the piezoelectric film 32 is arranged such that the uniaxial stretching direction forms an angle of approximately 45 ° with respect to the X direction and the Y direction. By performing such an arrangement, the pressing operation can be detected with higher sensitivity. It is most effective that the uniaxial stretching direction is 45 °, but substantially the same effect can be obtained even in the range of 45 ± 10 °.
　なお、延伸倍率は３～８倍程度が好適である。延伸後に熱処理を施すことにより、ポリ乳酸の延びきり鎖結晶の結晶化が促進され圧電定数が向上する。また、二軸延伸した場合はそれぞれの軸の延伸倍率を異ならせることによって一軸延伸と同様の効果を得ることができる。例えば、ある方向をＸ軸としてＸ軸方向に８倍、Ｘ軸に直交するＹ軸方向に２倍の延伸を施した場合、圧電定数に関してはおよそＸ軸方向に４倍の一軸延伸を施した場合とほぼ同等の効果が得られる。単純に一軸延伸したフィルムは延伸軸方向に沿って裂け易いため、前述したような二軸延伸を行うことにより幾分強度を増すことができる。 The stretching ratio is preferably about 3 to 8 times. By performing a heat treatment after stretching, crystallization of extended chain crystals of polylactic acid is promoted, and the piezoelectric constant is improved. In the case of biaxial stretching, the same effect as uniaxial stretching can be obtained by making the stretching ratio of each axis different. For example, when stretching is performed eight times in the X-axis direction and two times in the Y-axis direction orthogonal to the X-axis with a certain direction as the X-axis, uniaxial stretching is performed about four times in the X-axis direction with respect to the piezoelectric constant. The same effect as in the case can be obtained. Since a uniaxially stretched film is easily torn along the stretching axis direction, the strength can be increased somewhat by performing the biaxial stretching as described above.
　図４に示す様に、感圧センサ３０には、基準電圧源９０および電荷電圧変換回路９１が接続されている。基準電圧源９０は、感圧センサ３０の第１電極３１または第２電極３３に基準電圧を印加する。 (4) As shown in FIG. 4, a reference voltage source 90 and a charge-voltage conversion circuit 91 are connected to the pressure-sensitive sensor 30. The reference voltage source 90 applies a reference voltage to the first electrode 31 or the second electrode 33 of the pressure sensor 30.
　利用者が表面パネル４０を押圧すると、圧電フィルム３２は、電荷を発生する。電荷電圧変換回路９１は、第１電極３１または第２電極３３に接続され、圧電フィルム３２で生じた電荷を電圧に変換する。 When the user presses the front panel 40, the piezoelectric film 32 generates electric charges. The charge-voltage conversion circuit 91 is connected to the first electrode 31 or the second electrode 33, and converts a charge generated in the piezoelectric film 32 into a voltage.
　図５は、電荷電圧変換回路９１の構成例を示す回路図である。電荷電圧変換回路９１は、オペアンプＡ、抵抗Ｒ、およびコンデンサＣを備える。オペアンプＡの反転入力端子は、第１電極３１または第２電極３３に接続されている。オペアンプＡの非反転入力端子は、基準電圧源９０に接続されている。オペアンプＡの出力端子は、抵抗ＲおよびコンデンサＣの並列回路を介して、オペアンプＡの反転入力端子にフィードバック接続される。このような構成によって、電荷電圧変換回路９１は、積分回路を構成し、圧電フィルム３２で発生する電荷を電圧に変換する。 FIG. 5 is a circuit diagram showing a configuration example of the charge-voltage conversion circuit 91. The charge-voltage conversion circuit 91 includes an operational amplifier A, a resistor R, and a capacitor C. The inverting input terminal of the operational amplifier A is connected to the first electrode 31 or the second electrode 33. The non-inverting input terminal of the operational amplifier A is connected to the reference voltage source 90. An output terminal of the operational amplifier A is feedback-connected to an inverting input terminal of the operational amplifier A via a parallel circuit of a resistor R and a capacitor C. With such a configuration, the charge-voltage conversion circuit 91 forms an integration circuit, and converts charges generated in the piezoelectric film 32 into a voltage.
　電圧電流変換回路９２は、電荷電圧変換回路９１の出力する電圧信号を電流信号に変換する。電荷電圧変換回路９１は、例えば抵抗からなる。したがって、信号処理回路５１における検出回路５５Ｂには、圧電フィルム３２で生じた電荷に対応する電流信号が入力される。 The voltage / current conversion circuit 92 converts the voltage signal output from the charge / voltage conversion circuit 91 into a current signal. The charge-voltage conversion circuit 91 is composed of, for example, a resistor. Therefore, a current signal corresponding to the electric charge generated in the piezoelectric film 32 is input to the detection circuit 55B in the signal processing circuit 51.
　複数の検出回路５５Ａおよび検出回路５５Ｂは、いずれも静電容量式タッチセンサ用の検出回路である。つまり、検出回路５５Ａも検出回路５５Ｂも同じ種類の回路（本実施形態では電流検出用の回路）であり、いずれも、共通の処理部５８に接続される。 The plurality of detection circuits 55A and 55B are detection circuits for a capacitive touch sensor. That is, the detection circuit 55A and the detection circuit 55B are the same type of circuit (current detection circuit in this embodiment), and both are connected to the common processing unit 58.
　処理部５８は、検出回路５５Ａで検出される電流値に応じてタッチ操作の有無およびタッチ位置を検出する。また、処理部５８は、検出回路５５Ｂで検出される電流値に応じて押圧操作の有無および押圧量を検出する。 The processing unit 58 detects the presence or absence of a touch operation and the touch position according to the current value detected by the detection circuit 55A. Further, the processing unit 58 detects the presence or absence of a pressing operation and the amount of pressing according to the current value detected by the detection circuit 55B.
　静電容量式タッチセンサは、上述の様に、検出用の電圧信号を入力する。静電容量式タッチセンサは、検出用の電圧信号により継続して電荷が発生するため、検出回路には電流信号が入力される。静電容量式タッチセンサ用の検出回路は、当該電流信号を検出するための感度に調整されている。一方で、感圧センサは、利用者が押圧した場合に、断続的に電荷を生じる。そのため、静電容量式タッチセンサと感圧センサとでは、検出回路に流入する電荷量（電流値）は大きく異なる。しかし、本実施形態の感圧センサ３０は、電荷電圧変換回路９１および電圧電流変換回路９２を介して検出回路５５Ｂに接続される。したがって、感圧センサ３０で断続的に生じる電荷は、継続的に検知可能な電流信号に変換される。これにより、本実施形態のタッチパネルは、静電容量式タッチセンサ用の検出回路（第１検出回路である検出回路５５Ａおよび第２検出回路である検出回路５５Ｂ）を感圧センサ用の検出回路として兼用することができる。 (4) As described above, the capacitive touch sensor inputs a voltage signal for detection. In the capacitive touch sensor, electric charges are continuously generated by a detection voltage signal, and thus a current signal is input to the detection circuit. The detection circuit for the capacitive touch sensor is adjusted to have a sensitivity for detecting the current signal. On the other hand, the pressure-sensitive sensor generates an electric charge intermittently when the user presses it. Therefore, the amount of electric charge (current value) flowing into the detection circuit differs greatly between the capacitive touch sensor and the pressure-sensitive sensor. However, the pressure-sensitive sensor 30 of the present embodiment is connected to the detection circuit 55B via the charge-voltage conversion circuit 91 and the voltage-current conversion circuit 92. Therefore, the charge generated intermittently in the pressure-sensitive sensor 30 is converted into a continuously detectable current signal. Accordingly, the touch panel of the present embodiment uses the detection circuits for the capacitive touch sensor (the detection circuit 55A as the first detection circuit and the detection circuit 55B as the second detection circuit) as the detection circuits for the pressure-sensitive sensor. It can be shared.
　次に、図６は、電荷電圧変換回路９１の変形例を示す回路図である。図６の変形例に係る電荷電圧変換回路９１は、オペアンプＡ、抵抗Ｒ１，Ｒ２，Ｒ３、およびコンデンサＣを備える。オペアンプＡの反転入力端子は、第１電極３１または第２電極３３に接続されている。オペアンプＡの非反転入力端子は、電荷電圧変換回路９１の入力端子および基準電圧源９０に接続されている。また、非反転入力端子は、抵抗Ｒ１およびコンデンサＣの並列回路を介して、基準電圧源９０に接続されている。オペアンプＡの反転入力端子は、抵抗Ｒ２を介して基準電圧源９０に接続されている。また、オペアンプＡの出力端子は、抵抗Ｒ３を介して、オペアンプＡの反転入力端子にフィードバック接続される。 FIG. 6 is a circuit diagram showing a modification of the charge-voltage conversion circuit 91. 6 includes an operational amplifier A, resistors R1, R2, R3, and a capacitor C. The inverting input terminal of the operational amplifier A is connected to the first electrode 31 or the second electrode 33. The non-inverting input terminal of the operational amplifier A is connected to the input terminal of the charge-voltage conversion circuit 91 and the reference voltage source 90. The non-inverting input terminal is connected to a reference voltage source 90 via a parallel circuit of a resistor R1 and a capacitor C. The inverting input terminal of the operational amplifier A is connected to the reference voltage source 90 via the resistor R2. The output terminal of the operational amplifier A is feedback-connected to the inverting input terminal of the operational amplifier A via the resistor R3.
　このような構成によっても、電荷電圧変換回路９１は、積分回路を構成し、圧電フィルム３２で発生する電荷を電圧に変換する。また、図６に示す電荷電圧変換回路９１は、フィードバック抵抗Ｒ３と抵抗Ｒ２との比に応じた利得を有するため、増幅回路を構成する。よって、図６に示す電荷電圧変換回路９１は、感圧センサ３０の感度を高くすることができる。 も Even with such a configuration, the charge-voltage conversion circuit 91 forms an integration circuit, and converts the charge generated in the piezoelectric film 32 into a voltage. Further, the charge-voltage conversion circuit 91 shown in FIG. 6 has a gain according to the ratio between the feedback resistor R3 and the resistor R2, and thus constitutes an amplifier circuit. Therefore, the charge-voltage conversion circuit 91 shown in FIG. 6 can increase the sensitivity of the pressure-sensitive sensor 30.
　・タッチパネルの変形例１　
　次に、図７（Ａ）は、変形例１に係るタッチパネル１０Ｂの構成を示すブロック図である。図７（Ｂ）は、検出回路５５Ｂの一部構成を示す回路図である。検出回路５５Ａおよび検出回路５５Ｂは、上述の様に同じ構成を有するため、図７（Ｂ）では、代表して検出回路５５Ｂの構成を示す。 ・ Touch panel modification 1
Next, FIG. 7A is a block diagram illustrating a configuration of a touch panel 10B according to the first modification. FIG. 7B is a circuit diagram illustrating a partial configuration of the detection circuit 55B. Since the detection circuits 55A and 55B have the same configuration as described above, FIG. 7B shows the configuration of the detection circuit 55B as a representative.
　タッチパネル１０Ｂは、図４に示したタッチパネル１０に対して、電圧電流変換回路９２が省略されている。また、検出回路５５Ｂは、図７（Ｂ）に示す様に、少なくともサンプルホールド回路５５０と、ＡＤＣ（ＡＤコンバータ）５５１と、初期化回路５５２と、を含む。 The touch panel 10B is different from the touch panel 10 shown in FIG. 4 in that the voltage-current conversion circuit 92 is omitted. 7B, the detection circuit 55B includes at least a sample and hold circuit 550, an ADC (AD converter) 551, and an initialization circuit 552.
　タッチパネル１０Ｂのその他の構成は、図４に示したタッチパネル１０と同じ構成である。図４のタッチパネル１０と共通する構成については、同一の符号を付し、説明を省略する。 Other configurations of the touch panel 10B are the same as those of the touch panel 10 shown in FIG. The same components as those of the touch panel 10 of FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.
　検出回路５５Ｂは、タッチセンサ２０の測定タイミング毎に、初期化回路５５２とサンプルホールド回路５５０のコンデンサが接続され、サンプルホールド回路５５０のコンデンサが初期化される。その後、サンプルホールド回路５５０と初期化回路５５２との接続が解除され、電荷電圧変換回路９１にサンプルホールド回路５５０が接続される。また、サンプルホールド回路５５０およびＡＤＣ５５１が接続される。電荷電圧変換回路９１から出力される電圧信号は、サンプルホールド回路５５０によって保持される。ＡＤＣ５５１は、保持された電圧信号をデジタル変換する。 The detection circuit 55B is connected to the initialization circuit 552 and the capacitor of the sample and hold circuit 550 at each measurement timing of the touch sensor 20, and the capacitor of the sample and hold circuit 550 is initialized. Thereafter, the connection between the sample hold circuit 550 and the initialization circuit 552 is released, and the sample hold circuit 550 is connected to the charge-voltage conversion circuit 91. Further, the sample hold circuit 550 and the ADC 551 are connected. The voltage signal output from the charge-voltage conversion circuit 91 is held by the sample hold circuit 550. The ADC 551 converts the held voltage signal into a digital signal.
　この様な検出回路５５Ｂに流れる電流値Ｉは、サンプルホールド回路５５０内のコンデンサの容量Ｃ、電荷電圧変換回路９１の電圧値（測定開始時の電圧値）Ｖ、および単位時間あたりの測定回数ｎとすると、Ｉ＝ｎ・Ｃ・Ｖで表される。すなわち、検出回路５５Ｂに流れる電流値Ｉは、感圧センサ３０の出力値に比例する。 The current value I flowing through the detection circuit 55B is determined by the capacitance C of the capacitor in the sample and hold circuit 550, the voltage value (voltage value at the start of measurement) V of the charge-voltage conversion circuit 91, and the number of measurements n per unit time. Then, I = n · C · V. That is, the current value I flowing through the detection circuit 55B is proportional to the output value of the pressure-sensitive sensor 30.
　よって、電圧電流変換回路９２を省略した場合でも、電流検出用の回路である検出回路５５Ｂに感圧センサ３０を接続することができる。 Therefore, even when the voltage-current conversion circuit 92 is omitted, the pressure-sensitive sensor 30 can be connected to the detection circuit 55B, which is a current detection circuit.
　・タッチパネルの変形例２　
　次に、図８は、変形例２に係るタッチパネル１０Ｃの構成を示すブロック図である。図４と共通する構成については同一の符号を付し、説明を省略する。 ・ Touch panel modification 2
Next, FIG. 8 is a block diagram illustrating a configuration of a touch panel 10C according to the second modification. The same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
　電圧電流変換回路９２および検出回路５５Ｃは、コンデンサを介してグランドに接続される。また、検出回路５５Ｃは、信号生成回路５７に接続される。検出回路５５Ｃは、自己容量式のタッチセンサの検出回路である。検出回路５５Ｃは、本発明の「第２検出回路」の一例である。スマートフォン等の情報処理装置では、図８の例の様に、相互容量式の検出回路と、自己容量式の検出回路と、を備えている場合がある。変形例２に係る構成によれば、相互容量式の検出回路５５Ａおよび検出回路５５Ｂに代えて、自己容量式の検出回路５５Ｃに感圧センサ３０を接続することができる。 (4) The voltage-current conversion circuit 92 and the detection circuit 55C are connected to the ground via a capacitor. The detection circuit 55C is connected to the signal generation circuit 57. The detection circuit 55C is a detection circuit of a self-capacitive touch sensor. The detection circuit 55C is an example of the “second detection circuit” of the present invention. An information processing device such as a smartphone may include a mutual capacitance type detection circuit and a self-capacitance type detection circuit, as in the example of FIG. According to the configuration according to the second modification, the pressure-sensitive sensor 30 can be connected to the self-capacitance detection circuit 55C instead of the mutual capacitance detection circuit 55A and the detection circuit 55B.
　次に、図９は、電圧電流変換回路９２の変形例を示す回路図である。この変形例における電圧電流変換回路９２は、オペアンプＡ１，Ａ２、抵抗Ｒ１，Ｒ２，Ｒ３，Ｒ４，Ｒ５を備える。オペアンプＡ１の反転入力端子は、抵抗Ｒ１を介して基準電圧源９０に接続される。オペアンプＡ１の非反転入力端子は、抵抗Ｒ３を介して第１電極３１または第２電極３３に接続されている。オペアンプＡ１の出力端子は、抵抗Ｒ２を介してオペアンプＡ１の反転入力端子にフィードバック接続される。オペアンプＡ１の出力端子は、抵抗Ｒ５を介して出力端子およびオペアンプＡ２の非反転入力端子に接続される。オペアンプＡ２の出力端子は、反転入力端子にフィードバック接続される。また、オペアンプＡ２の出力端子は、抵抗Ｒ４を介してオペアンプＡ１の非反転入力端子にフィードバック接続される。 FIG. 9 is a circuit diagram showing a modified example of the voltage-current conversion circuit 92. The voltage-current conversion circuit 92 in this modification includes operational amplifiers A1 and A2 and resistors R1, R2, R3, R4, and R5. The inverting input terminal of the operational amplifier A1 is connected to the reference voltage source 90 via the resistor R1. The non-inverting input terminal of the operational amplifier A1 is connected to the first electrode 31 or the second electrode 33 via the resistor R3. The output terminal of the operational amplifier A1 is feedback-connected to the inverting input terminal of the operational amplifier A1 via the resistor R2. The output terminal of the operational amplifier A1 is connected via a resistor R5 to the output terminal and the non-inverting input terminal of the operational amplifier A2. The output terminal of the operational amplifier A2 is feedback-connected to the inverting input terminal. Further, the output terminal of the operational amplifier A2 is feedback-connected to the non-inverting input terminal of the operational amplifier A1 via the resistor R4.
　オペアンプＡ１は、抵抗Ｒ１および抵抗Ｒ２の比によって利得が決まる非反転増幅回路である。オペアンプＡ２は、ボルテージフォロワを構成する。後段の負荷抵抗が低い場合には、オペアンプＡ２は省略してもよい。 The operational amplifier A1 is a non-inverting amplifier circuit whose gain is determined by the ratio of the resistors R1 and R2. The operational amplifier A2 forms a voltage follower. When the load resistance at the subsequent stage is low, the operational amplifier A2 may be omitted.
　この様な構成により、電圧電流変換回路９２は、入力電圧値に応じた電流値を出力する。出力電流値は、抵抗Ｒ３，Ｒ４，Ｒ５の比によって決まる。この様な構成によれば、抵抗のみからなる電圧電流変換回路９２に比べて、電圧信号に対する電流信号の線形性が高くなる。 With such a configuration, the voltage-current conversion circuit 92 outputs a current value according to the input voltage value. The output current value is determined by the ratio of the resistors R3, R4, R5. According to such a configuration, the linearity of the current signal with respect to the voltage signal is higher than that of the voltage-current conversion circuit 92 including only the resistor.
　次に、図１０は、抵抗式の感圧センサ３０Ｆを用いる場合のタッチパネルの一部構成を示す回路図である。図１０に示す感圧センサ３０Ｆは、複数の抵抗から構成されるブリッジ回路からなる。感圧センサ３０Ｆの出力は、増幅回路９５に接続される。利用者が表面パネル４０を押圧すると、感圧センサ３０Ｆが歪み、ブリッジ回路を構成する各抵抗の値が変化する。したがって、増幅回路９５を構成するオペアンプの両入力端子に電位差が生じ、電圧電流変換回路９２に電圧信号が出力される。この様に、本発明の感圧センサは、圧電式に限らず、抵抗式であってもよい。 Next, FIG. 10 is a circuit diagram showing a partial configuration of the touch panel in the case of using the resistance type pressure-sensitive sensor 30F. The pressure-sensitive sensor 30F shown in FIG. 10 includes a bridge circuit including a plurality of resistors. The output of the pressure-sensitive sensor 30F is connected to the amplifier circuit 95. When the user presses the front panel 40, the pressure-sensitive sensor 30F is distorted, and the value of each resistor constituting the bridge circuit changes. Therefore, a potential difference is generated between both input terminals of the operational amplifier included in the amplification circuit 95, and a voltage signal is output to the voltage-current conversion circuit 92. Thus, the pressure-sensitive sensor of the present invention is not limited to the piezoelectric type, but may be a resistance type.
　・タッチパネルの変形例３　
　次に、図１１は、変形例３に係るタッチパネル１０Ｄの構成を示すブロック図である。図４と共通する構成については同一の符号を付し、説明を省略する。図１２（Ａ）は、タッチパネル１０Ｄを備えた表示装置１Ａの断面図である。 ・ Touch panel modification 3
Next, FIG. 11 is a block diagram illustrating a configuration of a touch panel 10D according to the third modification. The same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted. FIG. 12A is a cross-sectional view of a display device 1A including a touch panel 10D.
　表示装置１Ａは、第２感圧センサ３０Ｂおよびフレキシブル基板３００を備えている。第２感圧センサ３０Ｂは、感圧センサ３０よりも小型である。第２感圧センサ３０Ｂは、筐体５０の側面の内壁に配置されている。例えば、第２感圧センサ３０Ｂは、電源ボタンまたはボリュームボタン等の物理スイッチに代えて、利用者の側面を押圧する操作を検出するために設けられている。 The display device 1A includes the second pressure-sensitive sensor 30B and the flexible substrate 300. The second pressure sensor 30B is smaller than the pressure sensor 30. The second pressure-sensitive sensor 30 </ b> B is arranged on the inner wall on the side surface of the housing 50. For example, the second pressure-sensitive sensor 30B is provided to detect an operation of pressing the side of the user instead of a physical switch such as a power button or a volume button.
　第２感圧センサ３０Ｂは、フレキシブル基板３００を介して回路基板８０の基準電圧源９０および電荷電圧変換回路９１に接続されている。図１２（Ｂ）は、フレキシブル基板３００の平面図である。フレキシブル基板３００は、例えば樹脂基材からなり、可撓性を有する。フレキシブル基板３００は、形状がミアンダ状になっている。導体パターン３０１は、フレキシブル基板３００の形状に沿って、該フレキシブル基板３００の主面または内部に形成されている。 The second pressure sensor 30B is connected to the reference voltage source 90 and the charge-voltage conversion circuit 91 of the circuit board 80 via the flexible board 300. FIG. 12B is a plan view of the flexible substrate 300. The flexible substrate 300 is made of, for example, a resin base material and has flexibility. The flexible substrate 300 has a meandering shape. The conductor pattern 301 is formed on the main surface or inside of the flexible substrate 300 along the shape of the flexible substrate 300.
　回路基板８０は、静電容量式のセンサに近い位置に配置される。しかし、図１２（Ａ）の例の様に、回路基板８０は、静電容量式のセンサから遠い位置に配置される場合もある。本発明は、感圧センサを静電容量式のセンサの検出回路に接続することが特徴であるため、回路基板８０から遠い位置に配置した感圧センサから、静電容量式のセンサの回路まで配線を引き回す必要がある。このような場合、回路基板８０はディスプレイモジュール側に配置され、感圧センサは本体側に配置されることが多い。ディスプレイモジュールは組み立て工程の最後に本体に上部から張り合わせる。感圧センサと回路基板は、張り合わせの前に接続しなければならない。この場合、フレキシブル基板はある程度長さがないと、接続の作業性が悪くなる。したがって、作業時間の増大による組み立てコストの増大を招き、接続時にフレキシブル基板または接続用のコネクタを破損する可能性がある、といった課題がある。 The circuit board 80 is arranged at a position close to the capacitance type sensor. However, as in the example of FIG. 12A, the circuit board 80 may be arranged at a position far from the capacitance type sensor. Since the present invention is characterized in that the pressure-sensitive sensor is connected to the detection circuit of the capacitance-type sensor, from the pressure-sensitive sensor disposed far from the circuit board 80 to the circuit of the capacitance-type sensor Wiring needs to be routed. In such a case, the circuit board 80 is often arranged on the display module side, and the pressure-sensitive sensor is often arranged on the main body side. The display module is attached to the main body from above at the end of the assembly process. The pressure sensor and the circuit board must be connected before bonding. In this case, if the flexible substrate does not have a certain length, the operability of the connection deteriorates. Therefore, there is a problem that the assembling cost is increased due to an increase in operation time, and the flexible substrate or the connector for connection may be damaged at the time of connection.
　フレキシブル基板３００は、形状がミアンダ状になっている。そのため、フレキシブル基板３００を損傷することなく、ある程度引き伸ばすことが可能である。これにより、フレキシブル基板３００は、回路基板８０から離れた位置に第２感圧センサ３０Ｂを設置する場合でも、製造時に容易に取り付けることができ、上記課題を解決できる。 The flexible substrate 300 has a meandering shape. Therefore, the flexible substrate 300 can be stretched to some extent without being damaged. Thus, even when the second pressure-sensitive sensor 30B is installed at a position distant from the circuit board 80, the flexible substrate 300 can be easily attached at the time of manufacturing, and the above-described problem can be solved.
　・タッチパネルの変形例４　
　図１３は、変形例４に係るタッチパネル１０Ｅの構成を示すブロック図である。図４と共通する構成については同一の符号を付し、説明を省略する。 -Modification 4 of touch panel
FIG. 13 is a block diagram showing a configuration of a touch panel 10E according to the fourth modification. The same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
　タッチパネル１０Ｅは、信号処理回路５１に基準電圧源９０が内蔵されている。すなわち、基準電圧源９０は、タッチセンサ用の基準電圧源である。変形例４のタッチパネル１０Ｅでは、タッチセンサ用の基準電圧源を感圧センサ用の基準電圧源と兼用する。これにより、感圧センサ用の基準電圧源を別途用意する必要がなく、コストを低減することができる。また、タッチパネル１０Ｅ内の全ての基準電位が共通となり、基準電位に差が生じないため、使用可能な電圧範囲を大きくすることができる。また、基準電圧源９０を信号処理回路５１に内蔵することにより、基準電圧源として例えばバンドギャップ型基準電圧源といった電源電圧変動の影響を受けにくい基準電圧を利用できる。このため、感圧センサ３０の電源電圧変動の抑圧性能がよくなる。 In the touch panel 10E, the reference voltage source 90 is built in the signal processing circuit 51. That is, the reference voltage source 90 is a reference voltage source for a touch sensor. In touch panel 10E of Modification 4, the reference voltage source for the touch sensor is also used as the reference voltage source for the pressure-sensitive sensor. Accordingly, it is not necessary to separately prepare a reference voltage source for the pressure-sensitive sensor, and the cost can be reduced. In addition, since all the reference potentials in the touch panel 10E are common and there is no difference in the reference potentials, the usable voltage range can be increased. Further, by incorporating the reference voltage source 90 in the signal processing circuit 51, a reference voltage that is not easily affected by power supply voltage fluctuation, such as a band gap type reference voltage source, can be used as the reference voltage source. For this reason, the power-supply voltage fluctuation suppression performance of the pressure-sensitive sensor 30 is improved.
　・タッチパネルの変形例５　
　次に、図１４は、変形例５に係るタッチパネル１０Ｆの構成を示すブロック図である。図４と共通する構成については同一の符号を付し、説明を省略する。 -Modification 5 of touch panel
Next, FIG. 14 is a block diagram illustrating a configuration of a touch panel 10F according to Modification 5. The same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
　タッチパネル１０Ｆは、スイッチ回路９２０を備えている。スイッチ回路９２０は、検出回路５５Ａ、タッチセンサ２０、および電圧電流変換回路９２に接続されている。 (4) The touch panel 10F includes a switch circuit 920. The switch circuit 920 is connected to the detection circuit 55A, the touch sensor 20, and the voltage-current conversion circuit 92.
　変形例５に係るタッチパネル１０Ｆは、スイッチ回路９２０を切り替えて、検出回路５５Ａにタッチセンサ２０または電圧電流変換回路９２を接続する。これにより、タッチセンサ２０の検出回路５５Ａを感圧センサ３０用の検出回路として兼用する。 The touch panel 10F according to the fifth modification switches the switch circuit 920 to connect the touch sensor 20 or the voltage-current conversion circuit 92 to the detection circuit 55A. Thus, the detection circuit 55A of the touch sensor 20 is also used as a detection circuit for the pressure-sensitive sensor 30.
　図１５は、感圧センサの電極配置の他の例を示す平面図である。図１５の感圧センサ３０Ｃは、電荷検出用の電極が第２電極３３Ａおよび第２電極３３Ｂに分割されている。不図示の第１電極３１は、圧電フィルム３２の主面の略全面を覆うように配置されている。第２電極３３Ａおよび第２電極３３Ｂは、それぞれ異なる回路に接続される。 FIG. 15 is a plan view showing another example of the electrode arrangement of the pressure-sensitive sensor. In the pressure-sensitive sensor 30C of FIG. 15, the electrode for detecting electric charge is divided into a second electrode 33A and a second electrode 33B. The first electrode 31 (not shown) is disposed so as to cover substantially the entire main surface of the piezoelectric film 32. The second electrode 33A and the second electrode 33B are respectively connected to different circuits.
　図１６は、感圧センサ３０Ｃを備えたタッチパネル１０Ｇの構成を示すブロック図である。図４と共通する構成については同一の符号を付し、説明を省略する。 FIG. 16 is a block diagram illustrating a configuration of a touch panel 10G including the pressure-sensitive sensor 30C. The same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
　感圧センサ３０Ｃには、２つの電荷電圧変換回路９１にそれぞれ接続される。第２電極３３Ａおよび第２電極３３Ｂは、それぞれ異なる電荷電圧変換回路９１に接続される。これにより、第２電極３３Ａおよび第２電極３３Ｂのそれぞれについて生じる電荷（電流値）を処理する。つまり、処理部５８は、第２電極３３Ａおよび第２電極３３Ｂのそれぞれについて押圧操作がなされたか否かを判断することで、押圧位置を検出することができる。例えば、第２電極３３Ａに接続される検出回路５５Ｂで押圧操作が検出された場合には、処理部５８は、平面視して左側の位置で押圧操作がなされたと判断することができる。 に は The pressure-sensitive sensor 30C is connected to two charge-voltage conversion circuits 91, respectively. The second electrode 33A and the second electrode 33B are connected to different charge-voltage conversion circuits 91, respectively. Thereby, the charge (current value) generated for each of the second electrode 33A and the second electrode 33B is processed. That is, the processing unit 58 can detect the pressed position by determining whether the pressing operation has been performed on each of the second electrode 33A and the second electrode 33B. For example, when the detection circuit 55B connected to the second electrode 33A detects a pressing operation, the processing unit 58 can determine that the pressing operation has been performed at the left position in plan view.
　なお、１つの感圧センサの電極を分割するのではなく、複数の感圧センサに分割することでも、同じ構成および機能を発揮することができる。 The same configuration and function can be exhibited by dividing the electrode of one pressure-sensitive sensor into a plurality of pressure-sensitive sensors instead of dividing the electrode.
　なお、処理部５８は、検出回路（第１検出回路および第２検出回路）の合計数以上の操作パターンを検出することができる。例えば、処理部５８は、所定時間内に押圧が一度だけ行われるパターン（１タップパターン）や、所定時間以上押圧が継続するパターン（長押しパターン）、または所定時間内２回の押圧が繰り返されるパターン（ダブルタップパターン）、等の押圧操作をそれぞれ異なる操作パターンとして検出する。あるいは、処理部５８は、押圧量に応じて、異なる操作パターンとして検出してもよい。この様に、処理部５８は、１つの検出回路に対して、複数の操作パターンを検出することができる。 The processing unit 58 can detect operation patterns equal to or more than the total number of the detection circuits (the first detection circuit and the second detection circuit). For example, the processing unit 58 repeats a pattern in which pressing is performed only once within a predetermined time (one tap pattern), a pattern in which pressing is continued for a predetermined time or more (long pressing pattern), or pressing twice in a predetermined time. A pressing operation such as a pattern (double tap pattern) is detected as different operation patterns. Alternatively, the processing unit 58 may detect a different operation pattern according to the amount of pressing. As described above, the processing unit 58 can detect a plurality of operation patterns for one detection circuit.
　最後に、前記実施形態の説明は、すべての点で例示であり、制限的なものではないと考えられるべきである。本発明の範囲は、上述の実施形態ではなく、特許請求の範囲によって示される。さらに、本発明の範囲は、特許請求の範囲と均等の範囲を含む。 Lastly, the description of the above embodiment is merely an example in all respects, and should not be construed as limiting. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above. Further, the scope of the present invention includes the scope equivalent to the claims.
Ａ，Ａ１，Ａ２…オペアンプ
Ｃ…コンデンサ
Ｒ，Ｒ１，Ｒ２，Ｒ３，Ｒ４，Ｒ５…抵抗
１…表示装置
１０，１０Ｂ，１０Ｃ，１０Ｄ，１０Ｅ，１０Ｆ，１０Ｇ…タッチパネル
２０…タッチセンサ
２１…第１電極
２２…絶縁性基板
２３…第２電極
３０，３０Ｆ…感圧センサ
３０Ｂ…第２感圧センサ
３０Ｃ…感圧センサ
３１…第１電極
３２…圧電フィルム
３３，３３Ａ，３３Ｂ…第２電極
４０…表面パネル
５０…筐体
５１…信号処理回路
５５Ａ，５５Ｂ，５５Ｃ…検出回路
５７…信号生成回路
５８…処理部
７０…粘着剤
８０…回路基板
９０…基準電圧源
９１…電荷電圧変換回路
９２…電圧電流変換回路
９５…増幅回路
３００…フレキシブル基板
３０１…導体パターン
５５０…サンプルホールド回路
５５１…ＡＤＣ
５５２…初期化回路
９２０…スイッチ回路 A, A1, A2 ... operational amplifier C ... capacitors R, R1, R2, R3, R4, R5 ... resistor 1 ... display devices 10, 10B, 10C, 10D, 10E, 10F, 10G ... touch panel 20 ... touch sensor 21 ... first Electrode 22 Insulating substrate 23 Second electrode 30, 30F Pressure sensor 30B Second pressure sensor 30C Pressure sensor 31 First electrode 32 Piezoelectric films 33, 33A, 33B Second electrode 40 Front panel 50 Casing 51 Signal processing circuits 55A, 55B, 55C Detection circuit 57 Signal generation circuit 58 Processing unit 70 Adhesive 80 Circuit board 90 Reference voltage source 91 Charge voltage conversion circuit 92 Voltage Current conversion circuit 95 amplifier circuit 300 flexible substrate 301 conductor pattern 550 sample hold circuit 551 ADC
552: initialization circuit 920: switch circuit

Claims (13)

  1. 　第１の検出方式のタッチセンサと、
    　第１の検出方式とは異なる第２の検出方式の感圧センサと、
    　前記タッチセンサおよび前記感圧センサに接続される検出回路と、
    　前記検出回路に接続される処理部と、
    　を備えたタッチパネル。     A first detection type touch sensor;
    A pressure-sensitive sensor of a second detection method different from the first detection method;
    A detection circuit connected to the touch sensor and the pressure sensor;
    A processing unit connected to the detection circuit;
    Touch panel with.
  2. 　前記検出回路は、第１検出回路と、第２検出回路とを有し、
    　前記タッチセンサは、前記第１検出回路に接続され、
    　前記感圧センサは、前記第２検出回路に接続される、
    　請求項１に記載のタッチパネル。     The detection circuit has a first detection circuit and a second detection circuit,
    The touch sensor is connected to the first detection circuit,
    The pressure-sensitive sensor is connected to the second detection circuit;
    The touch panel according to claim 1.
  3. 　前記感圧センサは、圧電式または抵抗式である、
    　請求項１または請求項２に記載のタッチパネル。     The pressure-sensitive sensor is a piezoelectric type or a resistance type,
    The touch panel according to claim 1.
  4. 　前記処理部は前記第１の検出方式の信号を処理する、
    　請求項１乃至請求項３のいずれか１項に記載のタッチパネル。     The processing unit processes the signal of the first detection method,
    The touch panel according to claim 1.
  5. 　前記第１検出回路および前記第２検出回路は、電流検出用回路である、
    　請求項１乃至請求項４のいずれか１項に記載のタッチパネル。     The first detection circuit and the second detection circuit are current detection circuits,
    The touch panel according to claim 1.
  6. 　前記第２検出回路は、複数の第２検出回路を含み、
    　前記感圧センサは、いずれか一方の主面に複数の電極を備え、
    　前記複数の電極は、それぞれ異なる第２検出回路に接続される、
    　請求項１乃至請求項５のいずれか１項に記載のタッチパネル。     The second detection circuit includes a plurality of second detection circuits,
    The pressure-sensitive sensor includes a plurality of electrodes on any one main surface,
    The plurality of electrodes are connected to different second detection circuits, respectively.
    The touch panel according to claim 1.
  7. 　前記第２検出回路は、複数の第２検出回路を含み、
    　前記感圧センサは、複数の感圧センサを含み、
    　前記複数の感圧センサは、それぞれ異なる第２検出回路に接続される、
    　請求項１乃至請求項５のいずれか１項に記載のタッチパネル。     The second detection circuit includes a plurality of second detection circuits,
    The pressure sensor includes a plurality of pressure sensors,
    The plurality of pressure sensors are connected to different second detection circuits, respectively.
    The touch panel according to claim 1.
  8. 　前記複数の第２検出回路は、それぞれ電流検出用回路である、
    　請求項６または請求項７に記載のタッチパネル。     The plurality of second detection circuits are current detection circuits, respectively.
    The touch panel according to claim 6.
  9. 　前記処理部は、前記第１検出回路および前記第２検出回路の合計数以上の操作パターンを検出する、
    　請求項１乃至請求項８のいずれか１項に記載のタッチパネル。     The processing unit detects an operation pattern equal to or more than the total number of the first detection circuit and the second detection circuit,
    The touch panel according to claim 1.
  10. 　電荷電圧変換回路と、
    　電圧電流変換回路と、
    　を備え、
    　前記第２検出回路は、前記電荷電圧変換回路および前記電圧電流変換回路を介して、前記感圧センサに接続される、
    　請求項１乃至請求項９のいずれか１項に記載のタッチパネル。     A charge-voltage conversion circuit,
    A voltage-current conversion circuit,
    With
    The second detection circuit is connected to the pressure-sensitive sensor via the charge-voltage conversion circuit and the voltage-current conversion circuit,
    The touch panel according to claim 1.
  11. 　前記電圧電流変換回路は、増幅回路を含む、
    　請求項１０に記載のタッチパネル。     The voltage-current conversion circuit includes an amplification circuit,
    The touch panel according to claim 10.
  12. 　可撓性を有し、ミアンダ状のフレキシブル基板を備え、
    　前記第２検出回路は、前記フレキシブル基板の前記ミアンダ状の導体を介して前記感圧センサに接続される、
    　請求項１乃至請求項１１のいずれか１項に記載のタッチパネル。     Having flexibility, comprising a meander-like flexible substrate,
    The second detection circuit is connected to the pressure-sensitive sensor via the meandering conductor of the flexible substrate,
    The touch panel according to claim 1.
  13. 　前記処理部は、前記第１検出回路および前記第２検出回路の検出結果を処理する、
    　請求項１乃至請求項１２のいずれか１項に記載のタッチパネル。     The processing unit processes detection results of the first detection circuit and the second detection circuit,
    The touch panel according to claim 1.
PCT/JP2019/031634 2018-08-29 2019-08-09 Touch panel WO2020045058A1 (en)

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WO2015046289A1 (en) * 2013-09-27 2015-04-02 株式会社村田製作所 Touch input device
WO2017109455A1 (en) * 2015-12-23 2017-06-29 Cambridge Touch Technologies, Ltd Pressure-sensitive touch panel
WO2018052096A1 (en) * 2016-09-14 2018-03-22 ソニー株式会社 Sensor, input device, and electronic device

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JP6746090B2 (en) * 2015-10-06 2020-08-26 大日本印刷株式会社 Line segment input system
GB2565305A (en) * 2017-08-08 2019-02-13 Cambridge Touch Tech Ltd Device for processing signals from a pressure-sensing touch panel

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Publication number Priority date Publication date Assignee Title
WO2015046289A1 (en) * 2013-09-27 2015-04-02 株式会社村田製作所 Touch input device
WO2017109455A1 (en) * 2015-12-23 2017-06-29 Cambridge Touch Technologies, Ltd Pressure-sensitive touch panel
WO2018052096A1 (en) * 2016-09-14 2018-03-22 ソニー株式会社 Sensor, input device, and electronic device

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