JP5617735B2 - Human body communication type touch panel - Google Patents

Description

  The present invention relates to a human body communication type touch panel that outputs input operation data as if there was an input operation when a detection electrode pattern arranged on an input operation surface of the touch panel detects a natural oscillation signal via a capacitance. More specifically, the present invention relates to a human body communication type touch panel that identifies two types of input operations that differ depending on whether or not a transmitter is owned, and outputs input operation data.

  Detection by detecting the natural oscillation signal on the touch panel side by allowing the operator to own a transmitter that outputs the natural oscillation signal of the natural frequency, outputting the natural oscillation signal from the fingertip to the detection electrode pattern of the touch panel via the operator's human body A human body communication type touch panel (hereinafter simply referred to as a touch panel) that detects an input operation from an electrode pattern is known (Patent Document 1).

  The conventional touch panel 100 will be described with reference to FIGS. 5 and 6. As shown in FIG. 5, the operator 10 has a natural oscillation signal having a natural frequency f between the built-in oscillator and the transmission electrode 103 and the ground electrode 104. The transmitter 102 that outputs a signal is wound, the belt 101 is wound around the arm, the transmission electrode 103 and the ground electrode 104 are brought into contact with the arm of the operator 10, and the natural oscillation signal output from the transmitter 102 is passed through the human body of the operator 10. Output from the finger 10a.

  On the other hand, on the touch panel 100, one surface of the insulating panel 105 is used as an input operation surface, and a large number of detection electrode patterns 106 are wired so as to be insulated from each other on the input operation surface. Each detection electrode pattern 106 is connected to a tuning circuit type detector 107 that detects an induced voltage generated in each detection electrode pattern 106. When an induction voltage is detected from any of the detection electrode patterns 106, according to the frequency, A detection signal is output to any one of the output terminals 108a, 108b,.

  When the operator 10 who has wrapped the transmitter 102 around his / her arm performs an input operation by touching one of the detection electrode patterns 106 arranged on the input operation surface of the touch panel 100 with the finger 10a, the uniqueness output from the transmitter 102 is displayed. A natural oscillation signal having a frequency f flows through the body of the operator 10 and is output to the detection electrode pattern 106 touched by the finger 10a. The tuning circuit type detector 107 detects input operation data indicating detection of an input operation from any one of the output terminals 108n corresponding to the natural frequency f by detecting the natural oscillation signal of the natural frequency f from the detection electrode pattern 106. Output.

  The natural frequency f of the natural oscillation signal output from the transmitter 102 can be arbitrarily set. By setting different natural frequencies f for the plurality of transmitters 102, the natural frequency f set for each transmitter 102 owned by the operator 10 is set. Input operation data is output from the output terminals 108a, 108b,... 108n according to the frequency f, and the input operation for each transmitter 102 that is owned can be identified.

  Further, if the demodulation signal for demodulating the unique identification data from the modulation signal is provided on the touch panel 100 side including the modulation signal modulated by the unique identification data in the natural oscillation signal output from the transmitter 102, the natural frequency f is different. Even if the frequency is not set, the input operation from the operator 10 who owns the specific transmitter 102 can be identified.

JP 2002-366291 A (Items 0037 to 0056, FIGS. 9 and 10)

  The human body communication type touch panel 100 disclosed in Patent Document 1 can identify the input operation of the operator 10 who has a different transmitter 102 for each transmitter 102, but the transmitter 102 is wrapped around the arm, etc. Therefore, it is necessary to arrange the operator 10 around the operator 10, and an input operation is not detected unless the transmitter 102 is owned.

  For example, when the touch panel 100 is used as an input device for an electronic lock that locks a door installed at the entrance of a housing complex, a specific person such as a resident has the transmitter 102, and the specific that owns the transmitter 102 is specified. The electronic lock can be unlocked by a human input operation, but a specific person who has forgotten the transmitter 102 or a general operator 10 does not own the transmitter 102 and can thus recognize the input operation. In addition, it could not be unlocked by auxiliary input operations such as password and occupant's room number. After all, it is necessary to provide another touch panel for the auxiliary input operation, and only the conventional touch panel 100 cannot be used alone as an electronic lock input device.

  The present invention has been made in view of such conventional problems, and provides a human body communication type touch panel that detects an input operation even by an operator who does not own a transmitter. The purpose is to do.

  It is another object of the present invention to provide a human body communication type touch panel that identifies two types of input operations depending on whether the transmitter is owned or not and outputs input operation data.

  It is another object of the present invention to provide a human body communication type touch panel capable of detecting an input operation of an operator who does not own a transmitter without selecting a use environment by improving a simple circuit configuration.

  In order to achieve the above object, a human body communication type touch panel according to claim 1 is provided with one or more detection electrode patterns disposed on one surface of an insulating panel so as to be insulated from each other, and a transmitter disposed around an operator. And a first signal detecting means for detecting the first natural oscillation signal of the natural frequency f1 output from each detection electrode pattern, wherein the first signal detection means is the first from any one or two or more detection electrode patterns. A human body communication type touch panel that outputs input operation data indicating detection of an input operation on the assumption that there has been an input operation to the detection electrode pattern when a natural oscillation signal is detected, the second natural touch panel having a natural frequency f2 An oscillation circuit that outputs an oscillation signal, a potential oscillation unit that oscillates the potential of each detection electrode pattern at the natural frequency f2 by the second natural oscillation signal, and each detection electrode pattern and the potential are synchronized. And a second signal detecting means for detecting a second natural oscillation signal whose relative potential with each detection electrode pattern fluctuates at the natural frequency f2, wherein the second signal detecting means is any one or two or more. When the second natural oscillation signal is detected from the detection electrode pattern, it is assumed that an input operation to the detection electrode pattern has been performed, and input operation data indicating detection of the input operation is output.

  When an operator who places the transmitter around the user performs an input operation with his finger approaching the detection electrode pattern, the first natural oscillation signal of the natural frequency f1 output from the transmitter flows into the operator's body, and the operation is performed. It is output to a detection electrode pattern whose capacitance increases as it approaches from the person's finger. When detecting the first natural oscillation signal from the detection electrode pattern, the first signal detection means outputs input operation data indicating the detection of the input operation on the assumption that there has been an input operation to the detection electrode pattern.

  When an operator who does not own the transmitter performs an input operation with the finger approaching the detection electrode pattern, the capacitance between the operator's finger and the detection electrode pattern increases, so that the potential vibrates at the natural frequency f2. A second natural oscillation signal having a natural frequency f2 is output from the detection electrode pattern to a finger having a constant potential. Since the relative potential between the second signal detecting means whose potential fluctuates in synchronization with each detection electrode pattern and the detection electrode pattern from which the second natural oscillation signal is output to the finger fluctuates at the natural frequency f2, the second signal When detecting the second natural oscillation signal from the detection electrode pattern, the detection means outputs input operation data indicating detection of the input operation on the assumption that there has been an input operation to the detection electrode pattern.

  In the human body communication type touch panel according to claim 2, the transmitter includes the modulated signal modulated by the unique identification data in the first natural oscillation signal of the natural frequency f1 having the same frequency as the natural frequency f2, and outputs the first signal. The detecting means has a demodulating means for demodulating the unique identification data from the modulation signal included in the first natural oscillation signal, and detects the first natural oscillation signal because the demodulated signal includes the unique identification data. Features.

  An input operation by an operator who arranges transmitters around can be identified for each transmitter from the unique identification data.

  The human body communication type touch panel according to claim 3 includes identification data for identifying the detection of the first natural oscillation signal by the first signal detection means and the detection of the second natural oscillation signal by the second signal detection means in the input operation data. Output.

  From the identification data, an input operation using the transmitter and an input operation not using the transmitter can be identified.

  The human body communication type touch panel according to claim 4, wherein the potential oscillation means is connected to the reference power supply circuit through a reference power supply circuit connected to a DC power supply at a constant potential and a high impedance with respect to the natural frequency f2, A vibration power supply circuit connected to each detection electrode pattern, and an oscillation circuit connected to the vibration power supply circuit and driven by the output of a DC power supply via the inductor and a capacitor disposed between the reference power supply circuit, The natural frequency f2 of the second natural oscillation signal output from the oscillation circuit to the reference power supply circuit via the vicinity of the series resonance frequency where the inductor and the capacitor are connected in series is amplified to amplify the second natural oscillation signal and detect each electrode pattern It is characterized by oscillating the potential.

  Since the reference power supply circuit and the vibration power supply circuit are connected via an inductor having a high impedance to the second natural oscillation signal having the natural frequency f2, the second natural oscillation is connected from the oscillation circuit connected to the vibration power supply circuit via the capacitor. When the signal is output to the reference power supply circuit, the voltage of the vibration power supply circuit varies with the natural frequency f2 of the second natural oscillation signal with respect to the constant potential reference power supply circuit. The inductor between the reference power supply circuit and the vibration power supply circuit and the capacitor between the oscillation circuit and the reference power supply circuit are connected in series, and the natural frequency f2 is in the vicinity of the series resonance frequency. On the other hand, the voltage Vo of the vibration power supply circuit is amplified. As a result, the potential of the detection electrode pattern connected to the vibration power supply circuit can be enlarged and vibrated, and the second natural oscillation signal generated in the detection electrode pattern can be generated even if the capacitance Cf with the finger is very small. It can be amplified to a level that is easy to detect.

  According to the first aspect of the present invention, it is possible to detect two types of input operations, that is, an input operation by an operator who arranges a transmitter in the vicinity and an input operation by an operator who does not own the transmitter.

  If the respective frequencies are adjusted so that the natural frequency f1 of the first natural oscillation signal and the natural frequency f2 of the second natural oscillation signal are different, the transmitter is arranged around the frequency of the natural oscillation signal detected by the detection electrode pattern. It is possible to discriminate between the input operation by the operator who has performed the operation and the input operation by the operator who does not own the transmitter.

  Further, an input operation of an operator who does not own the transmitter can be detected by a simple improvement in which a potential oscillating means for oscillating the potential of the detection electrode pattern at the natural frequency f2 is used by using the same detection electrode pattern.

  Further, since a common mode signal generated from a commercial AC power source or the like is not used as a natural oscillation signal for detecting an input operation, an input operation of an operator who does not have a transmitter can be detected without being limited in use environment.

  According to the invention of claim 2, since the natural frequency f1 of the first natural oscillation signal and the natural frequency f2 of the second natural oscillation signal are the same frequency, the first natural oscillation signal is detected by the common detection circuit from the detection electrode pattern. Since the second natural oscillation signal can be detected and the modulation signal modulated by the unique identification data is included, the first natural oscillation signal can be identified from the second natural oscillation signal.

  Since the input operation of the operator who placed the transmitter around can be identified for each transmitter from the unique identification data, a unique command limited to the operator who owns the specific transmitter can be executed. .

  According to the invention of claim 3, it is possible to discriminate an input operation by an operator who arranges the transmitter around and an input operation by an operator who does not own the transmitter from the identification data included in the input operation data. The command executed by the input operation and the input screen display can be varied depending on the presence or absence.

  According to the invention of claim 4, the reference power supply circuit to which the DC power supply is connected and the vibration power supply circuit to which the detection electrode pattern is connected are separated without using an expensive insulating component such as an insulation type DC-DC converter, The voltage of the vibration power supply circuit can be varied at the natural frequency f2.

  In addition, even if the capacitance between the operator's finger and the detection electrode pattern is very small, the level of the natural oscillation signal generated in the detection electrode pattern is expanded, and the input operation is ensured from the minute change in capacitance. It can be detected. Therefore, the input operation can be performed without contact without touching the detection electrode pattern with the finger of the operator.

1 is a block diagram showing a human body communication touch panel 1 according to a first embodiment of the present invention. 2 is an equivalent circuit diagram of the human body communication type touch panel 1. FIG. It is a block diagram which shows the human body communication type touch panel 20 which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the human body communication type touch panel 30 which concerns on 3rd Embodiment of this invention. It is a top view which shows the state with which the transmitter 102 used for the conventional human body communication-type touch panel 100 was mounted | worn on the operator's 10 arm. It is a block diagram which shows the conventional human body communication type touch panel.

  Hereinafter, a human body communication type touch panel (hereinafter referred to as a touch panel) 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. The touch panel 1 according to the present embodiment is used as an input operation device that unlocks or locks an electronic lock provided at an entrance door of an apartment house, and is stacked on a display element that displays input keys. The

  As shown in FIG. 1, the touch panel 1 includes main circuit components constituting the touch panel 1 divided into two types of a non-vibration side circuit board 2 and a vibration side circuit board 3. The non-vibration circuit board 2 is provided with a reference power supply circuit 4 including a low-voltage reference power supply line GND and a high-voltage reference power supply line VCC that are set to the ground potential, and a DC voltage Vcc between the low-voltage reference power supply line GND and the high-voltage reference power supply line VCC. Is connected to a DC power source 5. Thereby, each circuit component such as the interface circuit 6 mounted on the non-vibration circuit board 2 is connected to the reference power supply circuit 4 and driven by the output voltage Vcc of the DC power supply 5.

  On the vibration side circuit board 3, a vibration power supply circuit 7 including a low voltage vibration power supply line SGND and a high voltage vibration power supply line SVCC is wired. The low-voltage vibration power supply line SGND is connected to the low-voltage reference power supply line GND, and the high-voltage vibration power supply line SVCC is connected to the high-voltage reference power supply line VCC via the coils 8 and 9, respectively. The inductances of the coil 8 and the coil 9 are both set to a value having a high impedance with respect to a second natural oscillation signal SG2 having a second natural frequency f2, which will be described later. Here, the coils 8 and 9 having the same inductance L Used. As a result, as shown in FIG. 1, the second natural oscillation signal SG2 having the second natural frequency f2 is synchronized from the later-described oscillation circuit 15 to the low voltage reference power supply line GND and the high voltage reference power supply line VCC of the reference power supply circuit 4. When output, the low-voltage reference power line GND of the reference power supply circuit 4 is grounded and at a stable potential, so that the potentials of the low-voltage vibration power supply line SGND and the high-voltage vibration power supply line SVCC of the vibration power supply circuit 7 are synchronized with the second natural frequency. It fluctuates at f2, and the voltage between the two becomes the same DC output voltage Vcc as that of the reference power supply circuit 4.

  An input operation in which the operator 10 performs an input operation by bringing the finger 10a closer to the surface of the vibration side circuit board 3 on which an electronic component to be described later is not mounted or the surface of the insulating panel arranged in the vicinity of the vibration side circuit board 3 When the operator 10 performs an input operation with the finger 10a pointing toward the input operation surface, one or more of the detection electrode patterns 11 are arranged along the input operation surface. The detection electrode pattern 11 faces or approaches the finger 10a.

  When the operator 10 performs an input operation by bringing the finger 10a closer to the input operation surface of the touch panel 1, the capacitance Cf between the detection electrode pattern 11 and the finger 10a arranged at a position where the finger 10a approaches is increased. As shown in FIG. 1, when the operator 10 possesses a transmitter 40 that outputs a first natural oscillation signal SG1 having a first natural frequency f1 around, for example, a pocket of clothes, the operation is performed from the transmitter 40. The first natural oscillation signal SG1 flowing in the body of the person 10 and appearing on the finger 10a is transmitted to the detection electrode pattern 11 facing or approaching the finger 10a via the increasing capacitance Cf, and the detection electrode pattern 11 is The potential vibrates with a predetermined amplitude at the natural frequency f1. That is, when the operator 10 holding the transmitter 40 in the vicinity performs an input operation, the finger 10a passing through the body of the operator 10 vibrates to the detection electrode pattern 11 close to the input operation position at the first natural frequency f1. The first natural oscillation signal SG1 is output.

  On the other hand, all the detection electrode patterns 11 are connected to the high-voltage vibration power supply line SVCC of the vibration power supply circuit 7. Therefore, while the second natural oscillation signal SG 2 having the second natural frequency f 2 is output from the oscillation circuit 15, The potential of the detection electrode pattern 11 also vibrates at the second natural frequency f2 in synchronization with the vibration power supply circuit 7.

  While the potentials of all the detection electrode patterns 11 vibrate at the second natural frequency f2, the operator 10 who does not own the transmitter 40 is grounded at a substantially constant potential with a part of his / her feet grounded. Yes, the potential of the finger 10a of the operator 10 is also a constant potential. Accordingly, the voltage (relative potential) between the finger 10a and the detection electrode pattern 11 vibrates at the second natural frequency f2, the input finger 10a approaches, and the capacitance Cf with the finger 10a increases. 11, the second natural oscillation signal SG2 having the second natural frequency f2 is transmitted from the detection electrode pattern 11 to the finger 10a via the electrostatic capacitance Cf. When this is performed from the side of the vibration power supply circuit 7 that vibrates in synchronization with the detection electrode pattern 11 at the second natural frequency f2, the potential of the finger 10a to be relatively input vibrates at the second natural frequency f2, and the operator 10 The second natural oscillation signal SG2 that vibrates at the second natural frequency f2 is output from the finger 10a to the detection electrode pattern 11 close to the input operation position. Therefore, in the signal detection means (MPU 16 to be described later) driven by the vibration power supply circuit 7, the potential of the detection electrode pattern 11 facing or approaching the finger 10a of the operator 10 who does not have the transmitter 40 in the vicinity is the second natural frequency. Since it vibrates with a predetermined amplitude at f2, the second natural oscillation signal SG2 can be detected from the detection electrode pattern 11.

  On the vibration side circuit board 3, circuit elements of an analog multiplexer 12, band pass filters 13a and 13b, A / D converters 14a and 14b, an MPU (microprocessor unit) 16 and an oscillation circuit 15 are mounted. The circuit 7 is connected to the low-voltage vibration power supply line SGND and the high-voltage vibration power supply line SVCC, and operates by receiving the output voltage Vcc from the DC power supply 5.

  All the detection electrode patterns 11 are connected to the corresponding inputs of the analog multiplexer 12, and the analog multiplexer 12 is not shown in the drawing for all the detection electrode patterns 11 for each pattern at a constant scanning period by switching control from the MPU 16. It connects to the 1st band pass filter 13a and the 2nd band pass filter 13b via an amplifier circuit.

  The first band pass filter 13a cuts noise components other than the first natural frequency f1 of the first natural oscillation signal SG1 output from the transmitter 40, and passes a signal in a frequency band centered on the first natural frequency f1. And output to the first A / D converter 14a in the subsequent stage.

  Similarly, the second band pass filter 13b cuts noise components other than the second natural frequency f2 of the second natural oscillation signal SG2 output from the oscillation circuit 15, and has a frequency centered on the second natural frequency f2. The band signal is passed and output to the second A / D converter 14b in the subsequent stage.

  The first A / D converter 14a and the second A / D converter 14b sample at a frequency that is at least twice the natural frequencies f1, f2 of the input natural oscillation signals SG1, SG2, respectively, The level of the 2 natural oscillation signal SG2 is quantized and output to the MPU 16.

  The quantized data output from the A / D converters 14a and 14b represents the detection levels of the first natural oscillation signal SG1 and the second natural oscillation signal SG2 generated in the detection electrode pattern 11 that is selectively connected by the analog multiplexer 12 at that time. Therefore, the MPU 16 acting as the signal detection means of the detection electrode pattern 11 compares the total sum of the quantized data input from the A / D converters 14a and 14b during the connection period of the detection electrode pattern 11 with a predetermined threshold value.

  When the sum of the quantized data input from the first A / D converter 14a is equal to or greater than a predetermined threshold, it is determined that the first natural oscillation signal SG1 has been detected, and the operator 10 that owns the transmitter 40 The input operation position is detected from the input operation and the arrangement position of the detection electrode pattern 11 selected and connected by the analog multiplexer 12 at that time.

  The analog multiplexer 12, the second band pass filter 13b, the second A / D converter 14b, and the MPU 16 are all connected to the vibration power supply circuit 7, and each potential vibrates in synchronization with the potential of the detection electrode pattern 11. Therefore, the second natural oscillation signal SG2 generated in the detection electrode pattern 11 can be detected, and the MPU 16 can detect when the sum of the quantized data input from the second A / D converter 14b is equal to or greater than a predetermined threshold value. Determines that the second natural oscillation signal SG2 has been detected, the input operation by the operator 10 who does not own the transmitter 40, and the arrangement of the detection electrode pattern 11 selectively connected by the analog multiplexer 12 at that time The input operation position is detected from the position.

When the MPU 16 detects any input operation, the MPU 16 receives identification data indicating which one of the first natural oscillation signal SG1 and the second natural oscillation signal SG2 is detected, and input operation data including the input operation position. Is output to the interface circuit 6 mounted on the non-vibration circuit board 2 through the signal line insulated from the input circuit, and the interface circuit 6 uses the input operation data for USB communication, I ² C communication, and the like. Output to the electronic lock that is the host device.

  The electronic lock performs different operations depending on the identification data included in the input operation data. For example, when the identification data indicates detection of an input operation by the operator 10 who owns the transmitter 40, the door is immediately opened. When the input operation is detected by a general operator 10 who does not own the transmitter 40, the password is entered or the room number of the apartment is entered to display a display prompting the resident to call on the interphone. It is displayed on the device and unlocked by entering a password or operating from a resident.

  The oscillation circuit 15 is also connected to the vibration power supply circuit 7, and its potential vibrates in synchronization with the vibration power supply circuit 7. However, the DC voltage is cut off from the reference power supply circuit 4, and the low voltage reference power supply of the reference power supply circuit 4 is used. In order to output the second natural frequency f2 of the second natural oscillation signal SG2 to the line GND and the high-voltage reference power supply line VCC, the output is bifurcated, and the low-voltage reference of the reference power supply circuit 4 via the capacitors 17 and 18 respectively. The power supply line GND and the high-voltage reference power supply line VCC are connected. Although the capacitances of the capacitor 17 and the capacitor 18 are arbitrary, the capacitors 17 and 18 having the same capacitance C are used here.

  The MPU 16 controls the operation of the oscillation circuit 15 and outputs the second natural oscillation signal SG2 from the oscillation circuit 15 while detecting the input operation of the operator 10 who does not own the transmitter 40. Even if the detection electrode pattern 11 is vibrated at the second natural frequency f2, if the first natural frequency f1 and the second natural frequency f2 are different, the first natural oscillation signal SG1 of the first natural frequency f1, that is, the transmitter 40, is changed. The input operation of the own operator 10 can be detected. However, in order to detect the input operation of the operator 10 who owns the transmitter 40, the output of the oscillation circuit 15 that causes noise is stopped in order to detect the input operation more accurately. I am letting.

  Further, the MPU 16 controls the amplitude and the second natural frequency f2 of the second natural oscillation signal SG2 output from the oscillation circuit 15 to arbitrary values, and here, the amplitude (between peaks) at the second natural frequency f2 of 187 kHz. The second natural oscillation signal SG2 having a voltage Vp-p) of 5V is output. The reason why the second natural frequency f2 is set to 187 kHz will be described below.

  When the second natural oscillation signal SG2 having the second natural frequency f2 flows to the reference power supply circuit 4 and the vibration power supply circuit 7, the low voltage reference power supply line GND and the high voltage reference power supply line VCC, and the low voltage vibration power supply line SGND and the high voltage vibration power supply line are used. Assuming that the SVCs are connected in close proximity and these power supply lines are short-circuited in the band of the second natural frequency f2, the reference power supply circuit 4 and the vibration power supply circuit 7 in FIG. Shown in the figure.

As shown in FIG. 2, since capacitors 17 and 18 having a capacitance C are connected in parallel between the output of the oscillation circuit 15 connected to the vibration power supply circuit 7 and the reference power supply circuit 4, the combined capacitance is 2C. Further, the combined inductance of the coils 8 and 9 connected in parallel between the reference power supply circuit 4 and the vibration power supply circuit 7 is L / 2. These capacitors and inductors are connected in series in a closed circuit through which the second natural oscillation signal SG2 having the second natural frequency f2 flows. The amplitude (level) of the second natural oscillation signal SG2 is Vi, and the reference between both ends of the coils 8 and 9 is used. If the voltage between the power supply circuit 4 and the vibration power supply circuit 7 is Vo, and the angular velocity represented by 2πf is ω (rad / sec),
Vo = [ω ² LC / (ω ² LC-1)] Vi (1)
Here, the circuit shown in FIG. 2 resonates in series at ω ² LC = 1, and the frequency f _{0 at} that time is
f ₀ = 1 / [2π (LC) ^1/2 ] (2).

That is, if the resonance frequency f ₀ obtained from the relationship of the equation (2) is the second natural frequency f2 of the second natural oscillation signal SG2, the theory from the equation (1) is obtained with respect to the level of the second natural oscillation signal SG2. The potential of the upper vibration power supply circuit 7 vibrates at infinity, and the potential of the detection electrode pattern 11 connected to the vibration power supply circuit 7 can also vibrate infinitely. As a result, even if the capacitance between the detection electrode pattern 11 and the finger 10a is as small as about 10 pF, the voltage generated between the detection electrode pattern 11 and the finger 10a expands infinitely, so the second natural frequency f2 Thus, the level of the second natural oscillation signal SG2 output from the second A / D converter 14b to the MPU 16 increases, and the MPU 16 can easily detect it.

The actual touch panel 1 does not resonate at the frequency f ₀ obtained from the equation (2) due to the influence of inductance, stray capacitance, etc. of the reference power supply circuit 4 and the vibration power supply circuit 7, and the reference power supply circuit 4 and the vibration power supply circuit 7. Due to an energy loss or the like when the second natural oscillation signal SG2 flows, the vibration power supply circuit 7 vibrates with an amplitude expanded to a finite magnification with respect to the level of the second natural oscillation signal SG2. On the other hand, it is not possible to apply a large voltage to the detection electrode pattern 11 with the finger 10a of the operator 10 touches, that the vicinity of the second natural frequency f2 of the second natural oscillating signal SG2 is shifted from the resonance frequency f ₀ At the same time, the amplitude of the second natural oscillation signal SG2 is adjusted to limit the amplitude of the voltage oscillation of the detection electrode pattern 11 so as to be within the reference voltage of the second A / D converter 14b.

  The amplitude and the second natural frequency f2 of the second natural oscillation signal SG2 that need to be adjusted according to the usage environment and circuit constants such as the coils 8, 9 and the capacitors 17, 18 can be easily controlled by the MPU 16 as described above. Can be adjusted. The second natural frequency f2 can be an arbitrary frequency. However, around the commercial AC power line, the finger 10a of the operator 10 may vibrate due to the common mode noise of the frequency of the commercial AC power supply instead of a constant potential. Therefore, it is preferable to set the frequency excluding the frequency of the commercial AC power supply and its harmonics.

  For example, in the touch panel 1 shown in FIG. 1, assuming that the inductances of the coils 8 and 9 are 220 μH and the capacitances of the capacitors 17 and 18 are 330 pF, the second characteristic frequency f2 is 187 kHz and the second natural frequency f2 is 187 kHz. When the natural oscillation signal SG2 is output from the oscillation circuit 15, it has been actually measured that the vibration power supply circuit 7 and the detection electrode pattern 11 connected to the vibration power supply circuit 7 vibrate with an amplitude (Vp-p) of 4 times 20V.

  In the above-described first embodiment, the first natural frequency f1 of the first natural oscillation signal SG1 and the second natural frequency f2 of the second natural oscillation signal SG2 are different frequencies. If it is not necessary to identify ten input operations, the same frequency may be used. In addition, even with the same frequency, it is possible to identify the input operation of the operator 10 based on whether or not the transmitter 40 is owned, and hereinafter, the touch panel according to the second embodiment that can identify the input operation with this common frequency. 20 will be described with reference to FIG. Since the main configuration of the touch panel 20 is the same as that of the touch panel 1 according to the first embodiment, the same number is given to the configuration that acts the same, and the description thereof is omitted.

  As shown in FIG. 3, the first natural frequency of the first natural oscillation signal SG1 output from the transmitter 41 owned by the operator 10 in the vicinity and the second natural oscillation signal SG2 output from the oscillation circuit 15 are obtained. The two natural frequencies are the same frequency f3. The transmitter 41 includes a modulation circuit (not shown), and outputs a modulation signal modulated by unique identification data for identifying the transmitter 41 in the modulation circuit, included in the first natural oscillation signal SG1.

  In the second embodiment, when the first natural oscillation signal SG1 and the second natural oscillation signal SG2 having the same frequency f3 are superimposed on the detection electrode pattern 11, the potential does not vibrate at the frequency f3 due to the phase difference. Since the natural oscillation signals SG1 and SG2 may not be detected, the second natural oscillation from the oscillation circuit 15 is controlled by the MPU 16 when detecting an input operation from the operator 10 who owns the transmitter 41 in the vicinity. The output of the signal SG2 is stopped. Further, the inductances of the coil 8 and the coil 9 are set to values having high impedance with respect to the second natural oscillation signal SG2 having the second natural frequency f3.

  In this touch panel 20, since the first natural frequency of the first natural oscillation signal SG1 and the second natural frequency of the second natural oscillation signal SG2 are the common frequency f3, the bandpass filter connected to the output of the analog multiplexer 12 13c is only one element that passes a signal in a frequency band centered on the frequency f3, and both the first natural oscillation signal SG1 and the second natural oscillation signal SG2 generated in the detection electrode pattern 11 are A / Ds in the subsequent stage. It outputs to the converter 14c and the demodulation circuit 21.

  The A / D converter 14c samples at a frequency that is at least twice the frequency f3, quantizes the levels of the first natural oscillation signal SG1 and the second natural oscillation signal SG2, and outputs them to the MPU 16.

  Further, the demodulation circuit 21 connected in parallel with the A / D converter 14c between the analog multiplexer 12 and the MPU 16 tries to demodulate from the natural oscillation signal output from the analog multiplexer 12, and from the modulation signal included in the natural oscillation signal. When the unique identification data specifying the transmitter 41 is demodulated, the unique identification data is output to the MPU 16.

  In the MPU 16, when the unique identification data is input from the demodulation circuit 21, the first specific oscillation signal SG1 is detected when the sum of the quantized data input from the A / D converter 14c is equal to or greater than a predetermined threshold. It is determined that the input operation has been performed by the operator 10 who owns the transmitter 40 identified by the unique identification data, and the input from the arrangement position of the detection electrode pattern 11 selectively connected by the analog multiplexer 12 at that time. Detect the operation position. When the same unique identification data is input for adjacent detection electrode patterns 11, the sum of the quantized data input from each A / D converter 14c is compared to detect the input operation position.

  In the MPU 16, when the unique identification data is not input from the demodulation circuit 21 and the sum of the quantized data input from the A / D converter 14c is equal to or greater than a predetermined threshold, the second specific oscillation signal SG2 is detected. The input operation position is detected from the fact that there is an input operation by the operator 10 who does not own the transmitter 40 and the arrangement position of the detection electrode pattern 11 selected and connected by the analog multiplexer 12 at that time.

  When the MPU 16 detects the identification data indicating which of the first natural oscillation signal SG1 or the second natural oscillation signal SG2 is detected, its input operation position, and the first natural oscillation signal SG1, Input operation data including transmitter data for identifying the transmitter 40 from the identification data is output to the host device via the interface circuit 6.

  In the first and second embodiments described above, the reference potential reference power supply circuit 4 and the vibration power supply circuit 7 having the second potential are used as the potential vibration means for vibrating the potential of the detection electrode pattern 11 at the second natural frequencies f2 and f3. The inductances 8 and 9 having high impedance are connected to the second natural oscillation signal SG2 having the frequencies f2 and f3. However, like the touch panel 30 according to the third embodiment shown in FIG. The power supply circuit 4 and the vibration power supply circuit 7 may be connected by the insulated DC-DC converter 31, and the potential of the detection electrode pattern 11 connected to the vibration power supply circuit 7 may be vibrated at the second natural frequency f2. Since the touch panel 30 according to the third embodiment is the same as the touch panel 1 according to the first embodiment in the touch panel 1 according to the first embodiment, the same number is assigned to the same function. A description thereof will be omitted.

  In this touch panel 30, all circuit elements mounted on the vibration side circuit board 3 are insulated from the main body and surrounding devices by using an insulation type DC-DC converter 31, and vibrations are wired to the vibration side circuit board 3. The power supply circuit 7 is vibrated at the second natural frequency f2 of the second natural oscillation signal SG2.

  Therefore, unlike the touch panels 1 and 20, the oscillation circuit 32 that outputs the second natural oscillation signal SG2 having the second natural frequency f2 is mounted on the non-vibration side circuit board 2 that is insulated from the vibration side circuit board 3, and is non-vibration. The side circuit board 2 is connected to the reference power supply circuit 4 wired and operates with the DC voltage Vcc of the DC power supply 5. The output of the oscillation circuit 32 is connected to the low-voltage vibration power supply line SGND of the vibration power supply circuit 7, whereby the low-voltage vibration power supply line SGND and the high-voltage vibration power supply line SVCC maintain the potential difference of the output voltage of the isolated DC-DC converter 31. However, each potential vibrates in synchronization with the second natural frequency f2.

  Since the potentials of the detection electrode pattern 11, the PMU 16 and the like connected to the vibration power supply circuit 7 vibrate at the second natural frequency f2, the second natural frequency from the detection electrode pattern 11 in which the finger 10a of the operator 10 having a constant potential is brought close. The second natural oscillation signal SG2 of f2 can be detected.

  According to the touch panel 30 according to the third embodiment, the DC voltage of the vibration power supply circuit 7 is mounted on the vibration side circuit board 3 by the insulating DC-DC converter 31 with respect to the DC voltage Vcc of the DC power supply 5. It can be arbitrarily adjusted according to the operating voltage of circuit components such as the PMU 16.

  As described in each of the above-described embodiments, the transmitter 40 is not necessarily in direct contact with the operator 10, but if the transmitter 40 is arranged around the operator 10, such as a pocket of clothes, the transmitter 10. The first natural oscillation signal SG1 is generated in the detection electrode pattern 11 that is close to the finger 10a through the body, and the input operation can be detected in the PMU 16.

  Similarly, the input operation of the operator 10 can be detected in a non-contact manner through the increasing capacitance Cf without bringing the finger 10a of the operator 10 into contact with the detection electrode pattern 11.

  In each of the above-described embodiments, the plurality of detection electrode patterns 11 are arranged on the input operation surface, and the input operation position is also detected from the arrangement position of the detection electrode pattern 11 from which the natural oscillation signals SG1 and SG2 are detected. The touch panel may function as a capacitance switch that detects the natural oscillation signals SG1 and SG2 from one detection electrode pattern 11 and detects that only an input operation has been performed.

  The oscillation circuit 15 is provided separately from the MPU 16, but may be built in the MPU 16.

  Further, the potential oscillating means for oscillating the potential of the detection electrode pattern 11 at the second natural frequency f2 is not limited to the means of the touch panels 1 and 30 of the above-described embodiments.

  Since the output signal of the transmitter 40 that appears on the finger 10a through the body of the operator 10 is detected, the present invention is suitable for a human body communication type touch panel that detects an input operation of the operator 10.

1, 20, 30 Human body communication type touch panel 4 Reference power supply circuit 5 DC power supply 7 Vibration power supply circuit 8, 9 Inductor (potential vibration means)
DESCRIPTION OF SYMBOLS 10 Operator 11 Detection electrode pattern 15, 32 Oscillation circuit 16 PMU (1st signal detection means, 2nd signal detection means)
17, 18 Capacitor 21 Demodulation circuit (demodulation means)
31 Insulated DC-DC converter (potential oscillation means)
40 Transmitter SG1 First natural oscillation signal SG2 Second natural oscillation signal

Claims (4)

One or more detection electrode patterns disposed on one surface of the insulating panel so as to be insulated from each other;
First signal detecting means for detecting a first natural oscillation signal of a natural frequency f1 arranged around an operator and output from a transmitter from each detection electrode pattern;
When the first signal detection means detects the first natural oscillation signal from any one or two or more detection electrode patterns, it is assumed that there is an input operation to the detection electrode pattern, and the input operation indicates the detection of the input operation. A human body communication type touch panel that outputs data,
An oscillation circuit for outputting a second natural oscillation signal having a natural frequency f2,
A potential oscillating means for oscillating the potential of each detection electrode pattern at a natural frequency f2 by a second natural oscillation signal;
A second signal detecting means for detecting a second natural oscillation signal in which the potential varies with each detection electrode pattern synchronously, and the relative potential with each detection electrode pattern varies at the natural frequency f2.
When the second signal detecting means detects the second natural oscillation signal from any one or more of the detection electrode patterns, it is assumed that there has been an input operation to the detection electrode pattern, and an input operation indicating detection of the input operation A human body communication type touch panel that outputs data. The transmitter includes the modulated signal modulated by the unique identification data in the first natural oscillation signal of the natural frequency f1 having the same frequency as the natural frequency f2, and outputs the first natural oscillation signal.
The first signal detecting means has a demodulating means for demodulating the unique identification data from the modulation signal included in the first natural oscillation signal, and detects the first natural oscillation signal because the demodulation signal includes the unique identification data. The human body communication touch panel according to claim 1. The identification data for identifying the detection of the first natural oscillation signal by the first signal detection means and the detection of the second natural oscillation signal by the second signal detection means are included in the input operation data and output. The human body communication type touch panel according to claim 1 or 2. The potential oscillation means is
A reference power supply circuit connected to a DC power supply at a constant potential;
A vibration power supply circuit connected to the reference power supply circuit via an inductor having high impedance with respect to the natural frequency f2, and connected to each detection electrode pattern;
It consists of a capacitor that is connected to a vibration power supply circuit and is driven between the reference power supply circuit and an oscillation circuit that is driven by the output of a DC power supply through the inductor,
The natural frequency f2 of the second natural oscillation signal output from the oscillation circuit to the reference power supply circuit via the capacitor is set to the vicinity of the series resonance frequency in which the inductor and the capacitor are connected in series, and the second natural oscillation signal is amplified and detected. 2. The human body communication type touch panel according to claim 1, wherein the electric potential of the electrode pattern is vibrated.

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