JP6429112B2 - Capacitive coupling type electrostatic sensor - Google Patents

Description

  The present invention relates to an input device using a capacitive coupling method as an input method.

In recent years, input devices using the capacitive coupling method have been required to be installed outdoors, in bathrooms, and in places where water droplets are applied, such as in bathrooms.
For example, those described in Patent Document 1, Patent Document 2, and Patent Document 3 are known. In the capacitive touch switch device described in Patent Document 1, switch electrodes are printed on a PET film with silver paste. When the electrode is further bent, the resistance value of the register electrode is changed with the finger pressed against the touch switch on which the electrode sheet is mounted. It is described that an arithmetic circuit that measures the amount of change in capacitance and a nonvolatile memory that stores the amount of change in both resistance and capacitance are mounted to prevent malfunction due to water droplets.
The touch switch detection device described in Patent Document 2 employs a self-capacitance type capacitive touch switch, and detects the presence or absence of a user's operation based on the number of contact electrodes determined to be in contact with a finger. It describes that a detection threshold that is a criterion for determination is set.
The touch panel device described in Patent Document 3 employs a mutual capacitive capacitive touch panel, calculates a change distribution of the detection signal based on the detection signal change amount, and outputs the change distribution calculation unit, It is described that a determination unit is provided that determines that the contact with the capacitive touch panel is a water droplet when the peak value of the change amount distribution of the detection signal is equal to or less than a predetermined negative threshold value.
JP 2006-185745 A JP 2009-238701 A JP 2012-088899 A

Although the capacitance type touch switch device described in Patent Document 1 described above can prevent malfunction due to water droplets, it has a problem that the configuration is complicated because a resistor electrode for reading a resistance value is required. .

  Since the touch switch detection device described in Patent Document 2 employs a self-capacitance type capacitive touch switch, a detection signal when a change amount of a detection signal when a water droplet is detected detects a finger. Since the area of the water droplet on the touch switch changes and increases, there is a problem that it cannot be determined as a finger and erroneously reacts.

The touch panel device described in Patent Document 3 requires a change amount distribution calculation unit that calculates and outputs a change amount distribution of the detection signal based on the detection signal change amount. Furthermore, a storage unit for storing the variation distribution is necessary. Therefore, there is a problem that a lot of memory is required.
In addition, the detection signal change amount of the mutual capacitance type electrostatic touch panel outputs a positive value and a negative value centering on the zero value, and in the case of water, the detection signal change amount takes a negative value, In the case of contact, the detection signal change amount takes a positive value. This is because, when measuring the intersection of the transmitting electrode and the receiving electrode sequentially, if the water droplets are continuously placed at the intersection of a plurality of locations, the signal of the transmitting electrode being measured is not measured. Since there is a voltage at the reception side electrode, the detection signal of the reception side electrode that is absorbed and measured through the water droplets becomes small, and the change amount of the detection signal becomes a negative value.
However, when the distance between the transmission electrodes is different from the distance between the reception electrodes, and a water drop is placed only on one intersection of the transmission electrode and the reception electrode, the change in the detection signal of the place where the water drop is placed The quantity distribution shows a positive value. This is because the signal of the transmitting side electrode being measured is measured because the interval between the transmitting side electrodes is separated from the interval between the receiving side electrodes, and water droplets are not continuously placed at the intersections of a plurality of locations. There is very little absorption of the transmitter electrode and receiver electrode, and the location of the intersection of the transmitter electrode and receiver electrode on which the water drop is placed is air before the water drop is placed, and the water drop is in the air. On the other hand, since the relative permittivity is large, the change amount of the detection signal at the intersection where the water droplet is placed is a positive value, which is the same as the case of contact between the finger and the pen when the water droplet is not placed at the intersection. Such a detection signal change amount becomes a positive value, and coordinate input becomes possible. From this, there is a possibility of erroneous input as coordinate input by contact with a finger or pen. In addition, there is a possibility that it is impossible to determine which state is in the case where water drops are placed continuously at the intersections of multiple places, or when water drops are placed only on the intersections without being placed at the same multiple intersections. There is.

The present invention provides an electrostatic capacitance of a touch switch in which a plurality of switch electrodes made of a conductive material are arranged on an insulator, and a capacitor is formed between the switch electrodes belonging to the switch electrode group A and the switch electrodes belonging to the switch electrode group B. In order to measure capacitance, a signal generated by an oscillator is converted into a sin signal and a cos signal synchronized by a synchronous oscillation circuit, and a switch electrode belonging to the switch electrode group A to which the sin signal is applied is selected and driven. A line for selecting and connecting a current / voltage conversion circuit and a switch electrode belonging to the switch electrode group B via the wiring, a signal converted from current / voltage, and the sin signal and the cos signal are multiplied. and multiplication circuit, a low pass filter circuit having a DC signal a signal by said multiplication circuit, with measures the DC signal of voltage, In the capacitive coupling type electrostatic sensor composed of a control device that performs arithmetic processing, a state where the finger or the coordinate indicator is close to the touch switch, a state where the finger or the coordinate indicator is separated from the touch switch, and one Static means provided with means for discriminating between a state in which a conductor is placed on only one touch switch and a state in which one conductor is placed across a plurality of touch switches, and means for notifying the state by the discriminating means. The gist of the capacitive coupling type electrostatic sensor. The other means for solving will be described later in the mode for carrying out the invention.

In the present invention, even when switch electrodes having different resistance values are used, the true current value can be obtained by multiplying the output of the current / voltage conversion circuit by the multiplying circuit by the two of the sin signal and the cos signal having a phase difference of 90 degrees. Only the AC signal has a double AC frequency including the DC signal, and becomes a DC signal by passing through a low-pass filter. Even if the switch electrode is connected, all the frequencies are higher than the frequency of the sin signal, and the high frequency AC signal is passed through the low-pass filter so that even if a noise frequency other than the frequency of the sin signal is mixed into the switch electrode, it is accurate. Capacitance is generated between the switch electrode and the finger and hand, and the on / off state of the touch switch can be detected. When a water droplet is placed on the touch switch, it can be seen whether it is placed on the plurality of touch switches or on each of the plurality of touch switches. When a plurality of water droplets are placed across the touch switches, this information can be notified to the operator so that it can be understood that an erroneous input will occur if touched as it is. Furthermore, when touching in this state, even if one touch switch is touched, the operator can be notified that touches of a plurality of touch switches via water droplets may be erroneously input.
When the water droplets are not placed on the plurality of touch switches but are placed on the individual touch switches, the operator can be notified of the information on the water droplets. When touching in this state, an erroneous input has not occurred, but the operator can be notified that the touch is in a state where a water droplet is placed.

1 is a configuration diagram of a capacitive coupling type electrostatic sensor of Example 1. FIG. Schematic diagram of the touch switch of Example 1 Schematic diagram of switch electrodes for driving the temporary touch switch of Example 1 Multiplication circuit waveform diagram of embodiment 1 Example 1 Input Signal Level and Phase Difference Diagram Example 1 sin signal multiplication waveform diagram Relationship diagram between finger and switch electrode during finger measurement in Example 1 Relationship diagram between finger and switch electrode during finger measurement in Example 1 Relationship diagram between finger and switch electrode during finger measurement in Example 1 Relationship diagram between finger and switch electrode during finger measurement in Example 1 FIG. 3 is a diagram illustrating a relationship between a finger and a switch electrode during finger measurement according to the first embodiment. FIG. 3 is a diagram illustrating a relationship between a finger and a switch electrode during finger measurement according to the first embodiment. The correspondence table of the touch switch of Example 1 and a temporary touch switch. Control flow of embodiment 1 Control flow of embodiment 1 Control flow of embodiment 1 Control flow of embodiment 1 Control flow of embodiment 1 Control flow of embodiment 1 Memory configuration diagram of Embodiment 1 Schematic diagram of switch electrodes for driving the temporary touch switch of Example 2 Relationship diagram between finger and switch electrode during finger measurement in Example 2 Relationship diagram between finger and switch electrode during finger measurement in Example 2 Relationship diagram between finger and switch electrode during finger measurement in Example 2 The correspondence table of the touch switch of Example 2 and a temporary touch switch.

  The touch switch using the capacitive coupling method uses the area where the finger, hand, or coordinate indicator can touch the switch electrode as the touch switch, and the coordinate indicator held by the finger, hand, or hand is the touch switch. This is a digital input device that detects that the switch electrode has been approached and detects whether the touch switch is on or off.

The finger, hand, or coordinate indicator includes not only the fingertip and the edge of the hand, but also other human body parts, a touch pen having a tip formed of a conductive material, a stylus pen, and the like.
For example, the switch electrode is formed by printing an electrically conductive material on the surface of a PET film serving as an insulator by a screen printing method to form a touch switch. Screen printing is a printing method that uses an squeegee (rubber spatula or metal spatula) to push out ink from the space between the yarns called the opening (screen plate) and form an image pattern. It is a method rooted in Japan as a traditional craft such as sushi and printing.
Further, the thickness of the completed image pattern is the thickness of the screen plate used. Currently, screen printing has been established as an indispensable method in the electronics field, and screen printing is always used in the production of printed wiring boards, electronic components, flat panel displays, and automobile meters. It is known.
The switch electrode is printed by using silver paste (substance is silver) ink and ITO (indium oxide) (substance is tin) ink, which is a conductive material, on the surface of the PET film that becomes an insulator by screen printing. Forming a switch. The screen plate for forming the switch electrode has a thickness of 10 to 30 μm. Further, silver paste ink and ITO (indium tin oxide) ink, which are conductive materials, have high resistivity values, and have an area resistance of several Ω to several kΩ / cm ² . A switch in which a switch electrode is formed on a PET film is used as an input area of the touch switch, and the user's finger touches the input area of the touch switch through the PET film.
In the present invention, even when switch electrodes having different resistance values are used, a signal generated from an oscillator is converted into a sin signal whose phase is taken by two synchronous oscillation circuits and a cos signal having a phase difference of 90 degrees. One drives a signal via a switch electrode of a switch electrode group A via an amplifier circuit, and is connected to a switch electrode of another switch electrode group B through a resistor R of a current / voltage conversion circuit. One of the sin signals is connected to two multiplication circuits. The cos signal is connected to another multiplication circuit. The outputs of the current / voltage conversion circuits are connected to two multiplication circuits, respectively, and multiplied by the sin signal and the cos signal, respectively. The multiplied signal becomes a DC signal when only the AC signal of the true current value has a double AC frequency including the DC signal and passes through a low-pass filter.
Here, all the noises other than the frequencies of the sin signal and the cos signal mixed in the switch electrode become an AC signal having a frequency higher than the frequency of the sin signal / cos signal by multiplication with the sin signal / cos signal. This can be eliminated by passing a low-pass filter sufficiently lower than the signal frequency.
A capacitor is formed between the switch electrode of the connected switch electrode group A and the switch electrode of the switch electrode group B to constitute one touch switch. At this time, the switch electrode of the switch electrode group A and the switch electrode of the switch electrode group B that are not wired may be in an unconnected state, connected to GND, or connected to an intermediate potential of a sin signal or a cos signal. You may do it.

  As the scanning at this time, one switch electrode of the switch electrode group A constituting one touch switch and one switch electrode of the switch electrode group B are connected, the other switch electrodes are not connected, and are connected to GND. Alternatively, one touch switch is measured by connecting to an intermediate potential. Similarly, there is a method of sequentially measuring other touch switches.

  Further, as another scan, a plurality of switch electrodes of the switch electrode group A constituting one touch switch are connected, a switch electrode of one switch electrode group B is connected, and the other switch electrodes are not connected. Connect to GND or connect to intermediate potential and measure one touch switch. Similarly, there is a method of sequentially measuring other touch switches.

In addition, measurement of noise having the same frequency as the sin signal and the cos signal mixed in the switch electrode is performed by first connecting all the switch electrodes of the switch electrode group A to the unconnected or GND or intermediate potential. Then, one of the switch electrodes of the switch electrode group B is connected and measured. At this time, when a change appears in the signal, it is determined that noise of the same frequency is mixed. Then, by controlling the frequency of the signal generated by the oscillator, the frequency of the sin signal and the cos signal by the two synchronous oscillation circuits is changed from the signal from the oscillator, and the bandpass filter corresponding to the changed frequency Is provided. As a result, noise of harmonic components in the frequency band of the sin signal and cos signal to be used can be taken, and therefore it is desirable to use a band pass filter corresponding to the changed frequency.
Here, one touch switch will be described. A detection signal x obtained by multiplication of the sin signal and the cos signal is generated at each switch electrode connected to the drive of the sin signal and the resistor R of the current / voltage conversion circuit, and detection of y and x is performed. The signal is converted by each A / D converter through each low-pass filter to generate two pieces of digital data. This digital data is stored in the control device as a measurement value. The sin signal side of the measurement value is referred to as measurement value SW1_y, and the cos signal side is referred to as measurement value SW1_x. In particular, a measured value in an initialization state after power-on or the like is set as a reference value (hereinafter referred to as a base value), the sin signal side is referred to as a base value SW1_y_base, and the cos signal side is referred to as a base value SW1_x_base.
When measuring the state of the finger, hand, or coordinate indicator and switch electrode, measure the capacitance between the sin signal drive and the switch electrode connected to the resistor R of the current / voltage conversion circuit. Then, the difference SW1_y_dt and the difference SW1_x_dt of the measured value and the base value from the detection signal x obtained by multiplication with the sin signal at that time and the detection signal x obtained by multiplication of the cos signal are obtained. SW1_y_dt is (SW1_y-SW1_y_base), and SW1_x_dt is (SW1_x-x_base). From this, the change amount SW1_dt is obtained by calculating the equation route (square of SW1_y_dt + square of SW1_x_dt). In addition, the phase difference SW1_theta at this time is obtained from the equation arctangent (SW1_y_dt / SW1_x_dt). Then, the phase difference SW1_theta differs by about 180 ° between when the finger, hand, or coordinate indicator touches the touch switch and when a conductor such as water is placed, and this phase difference is used. The amount of change SW1_dt that has been reduced decreases when touched, and increases when a conductor such as water is placed.
Here, the above-described change SW1_dt and the phase difference SW1_theta are set to the reference change SW1_scale, the reference in a state where the reference metal rod is held in contact with the switch electrode through the PET film. Is stored in advance in the EEPROM as the phase difference SW1_deg.
Then, the change amount SW1_dt in the state of measuring the state of the finger, the hand, or the coordinate indicator and the switch electrode is normalized. This is to correct measurement differences due to the shape and size between the switch electrodes. The normalized value SW1_normal is expressed as a percentage by SW1_dt / SW1_scale × 100.
Furthermore, if the phase difference SW1_theta is within a range of ± 90 ° with respect to the reference phase difference SW1_deg, the finger, hand, or coordinate indicator touches the switch electrode constituting the touch switch via the PET film. It represents that. Moreover, if it is outside the range of ± 90 °, it means that water is placed on the switch electrode constituting the touch switch via the PET film. This is a process in which two sinusoidal oscillation circuits are 90 degrees out of phase with two sinusoidal oscillation circuits in the process of inputting to two multiplication circuits that are input from the path of the wiring that drives the switch electrodes of the switch electrode group A to which the sin signal is applied. This is to cope with a case where a phase delay occurs in the input from the path of the wiring that drives the switch electrodes of the switch electrode group A to which the sin signal is applied in the multiplication circuit that inputs the two cos signals.
In addition, the touch switch ON / OFF threshold SW1_threshold1 and the touch switch OFF / water mounting threshold SW1_threshold2 are previously input from the external processing apparatus, and are set in the EEPROM. The state of the touch switch ON when the finger, hand, or coordinate indicator touches the touch switch is such that the measured phase difference SW1_theta is within a range of ± 90 ° with respect to the reference phase difference SW1_deg, and The measured and normalized change amount SW1_normal is set to a negative value, and the negative value SW1_normal is equal to or less than the threshold value SW1_threshold1. At this time, when the threshold SW1_threshold1 is exceeded, the touch switch is OFF when the finger, hand, or coordinate indicator is not touching the touch switch. If the variation SW1_normal measured and normalized is greater than or equal to the threshold SW1_threshold2, if it is out of the range of ± 90 °, the touch switch mounted on the switch electrode constituting the touch switch When the touch switch is less than the threshold SW1_threshold2, the touch switch is off when the finger, hand, or coordinate indicator is not touching the touch switch. If the touch switch is placed in the water-mounted state, the touch switch is turned on. When the finger, hand, or coordinate indicator approaches the touch switch on which water is placed in the process of the state transition from the touch switch water placement state to the touch switch ON state, the touch switch temporarily An OFF state occurs. For this reason, when the touch switch is placed in the water-mounted state, the water-mounted state is held in the memory for a certain period of time, and when the touch switch is turned on, the water is placed in the memory. If this state is maintained, the touch switch is turned on when the water is placed.
Next, two touch switches will be described.
Each touch switch is in a state as described in the above-mentioned one touch switch. Furthermore, when water is placed across the two touch switches, the water is placed across the two touch switches. The state of the position is required. In order to generate this state, it is necessary to generate the states of the two touch switches from the states of the four temporary touch switches.
Two configurations of the four temporary touch switches each connect one switch electrode of the switch electrode group A of the temporary temporary touch switch and one switch electrode of the switch electrode group B. This is the configuration of the measurement method (1). Each of the other two configurations of the four temporary touch switches connects two switch electrodes of the switch electrode group A of the temporary one touch switch and one switch electrode of the switch electrode group B. This is the configuration of the measurement method (2). Alternatively, one switch electrode of one temporary touch switch of the switch electrode group A having a configuration of two temporary touch switches is connected to one switch electrode of the other temporary touch switch of the switch electrode group B. This is the measuring method (3). And, when water is placed across the two touch switches by the combination of (1) and (2) or the combination of (1) and (3), the state of the water placement across the two touch switches Occur. This is because, in the two temporary touch switches (2) and (3), the two touch switches according to the state of the two temporary touch switches (1) when it is determined that water is placed on the two. It is determined whether water has been placed across
When touching in a state where water is placed across the two touch switches, the two touch switches are turned on. The touch switch on which the finger, hand, or coordinate indicator is placing water in the process of state transition from the state where water is placed across the two touch switches to the state where the two touch switches are on When one approaches, the one touch switch or two touch switches are temporarily turned off. For this reason, when the touch switch is switched from the water mounting state to the touch switch OFF state, the water mounting state is held in the memory for a certain period of time and the two touch switches are turned on. Sometimes, when the water placement state is held across the memory, the touch switch ON state is placed across the water placement.
Then, the information of the two touch switches is notified to the external processing device. The information to be notified is that the touch switch is OFF, ON, the water placement state, the touch switch ON state in the water placement, the water placement state, the water placement state, and the touch switch ON in the water placement. State.
In particular, in the state where the water is placed across, it becomes warning information that may cause an erroneous input to the external processing device. In the state where the touch switch is turned on across the water placement, there is an erroneous input to the external processing device. This is error information that has occurred.
Three or more touch switches can operate by applying what has been described above for two touch switches between adjacent touch switches.

  Hereinafter, the present invention will be described in detail by way of examples. First, a first embodiment will be described with reference to FIGS.

FIG. 1 shows a configuration diagram in a case where information of touch switches 1 and 2 by the capacitive coupling type electrostatic sensor of the first embodiment is notified to an external processing device.
First, the control device 34 includes a CPU 3, a ROM 28 incorporating a program, a RAM 29 incorporating a working memory, an EEPROM 32 incorporating constants (for example, a threshold, a reference change amount, a reference phase difference), and a touch switch mounted. A timer 33 that holds the state of the device for a certain period of time, an oscillator 4 that outputs a signal to the synchronous oscillation circuits 5 and 6 that convert the signal into a sin signal and a cos signal, From the switch selection 27 that controls the switching circuit 8 that selects 102, the switch selection 26 that controls the switching circuit 13 that selects the switch electrodes 111 and 112 of the switch electrode group B11 that receives the sin signal, and the bandpass filter circuit 17 Band filter of the band pass filter circuit 17 corresponding to the frequency band of the sin signal The switch selection 25 for controlling the selection, the sin signal from the synchronous oscillation circuit 5 and the sin signal via the band-pass filter circuit 17 are multiplied by the multiplication circuit 19, and the signal via the low-pass filter 21 is converted into digital data. The A / D conversion circuit 23, the cos signal from the synchronous oscillation circuit 6 and the sin signal via the band-pass filter circuit 17 are multiplied by the multiplication circuit 20, and the signal via the low-pass filter 22 is converted into digital data A The A / D conversion circuit 24 and the external I / F 30 that outputs the information of the touch switch obtained by calculating the digital data of the two A / D conversion circuits 23 and 24 to the external processing device 31 are configured.
Here, in FIG. 2, the touch switch which is the notification information of the state of the touch switch 1 transmitted to the external processing device 31 is in the OFF state, the ON state, the water mounting state, and the touch switch ON state in the water mounting. The schematic diagram of six states of the state of water mounting across and the state of touch switch ON in water mounting across is shown. The same applies to the notification information of the state of the touch switch 2.
In FIG. 3, switch electrodes for driving the temporary touch switches 121 to 124 are shown. In the configuration of the temporary touch switch 121, the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 are driven by a pair, and the configuration of the temporary touch switch 122 is the switch electrode of the switch electrode group A10. 102 and the switch electrode 112 of the switch electrode group B11, and the temporary touch switch 123 is configured by the switch electrode 101 and the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11. The temporary touch switch 124 is composed of the switch electrode 101 and the switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11. Further, the configuration of the temporary touch switch 120 is driven only by the switch electrode 111 of the switch electrode group B11 without using the switch electrode of the switch electrode group A10.
Then, the switch electrodes that are not used in the temporary touch switch being measured are connected to an intermediate potential (hereinafter referred to as VGND) of the sin signal or the cos signal.
Then, the switch electrode group A10 and the switch electrode group B11 are formed on the PET film 9 serving as an insulator, and the user's finger passes through the PET film 9 in the input area of the touch switch 1 and the touch switch 2. Touch or water placement can be reflected in the state of the touch switch 1 and the touch switch 2 from the state of the temporary touch switches 121 to 124 at this time (see FIG. 13). The temporary touch switch 120 measures noise having the same frequency as that of the sin signal and the cos signal mixed in the switch electrode, and when there is noise, the oscillation frequency of the oscillator 4 is switched or a band-pass filter corresponding to the oscillation frequency. Used for switching the band-pass filter of the circuit 17.

An oscillation frequency output from the oscillator 4 is set by the CPU 3 of the control device 34, and a signal output from the oscillator 4 is converted into a 90-degree phase difference between the sin signal and the cos signal from the two synchronous oscillation circuits and output. When setting the oscillation frequency, the switching circuit 18 is controlled by the switch selection 25 to select the bandpass filter of the bandpass filter circuit 17 corresponding to the frequency band of the sin signal. The sin signal is connected by the amplifier circuit 7 to the switching circuit 8 for selecting a line for driving the switch electrodes 101 and 102 of the switch electrode group A10.
The voltage of the sine signal amplified through one of the switch electrodes 101 and 102 of the switch electrode group A10 to be driven selected by controlling the switching circuit 8 from the switch selection 27 causes the switching circuit 13 to switch from the other switch selection 26. A current flows through the resistor 14 through the switch electrodes 111 and 112 of the switch electrode group B11 paired with the selected switch electrodes 101 and 102.
At this time, the switch electrodes that are not selected are connected to VGND by controlling the switching circuit 8 from the switch selection 27 and the switching circuit 13 from the switch selection 26. The currents i0 to i4 via the switch electrodes 111 and 112 of the switch electrode group B of the temporary touch switches 120 to 124 are converted to voltages E0 to E4 by passing through the resistor 14 and amplified by the amplifier circuit 16. Then, the switching circuit 18 is controlled by the switch selection 25 to pass through the band-pass filter circuit 17 corresponding to the band of the sin signal to be generated by the oscillation frequency output from the oscillator 4, and the frequency other than the pass band of the sin signal frequency. To cut.
The frequency output via the bandpass filter circuit 17 is input to the y side of the two multiplication circuits 19 and 20, respectively. A sin signal and a cos signal are input to the X side of the two multiplication circuits 19 and 20. As a result of the multiplication circuits 19 and 20 passing through the respective multiplication circuits 19 and 20, the noise signals are eliminated in the low-pass filters 21 and 22 that pass a very low frequency band, and a DC signal is taken out. .
Each DC signal is converted into digital data by the A / D converters 23 and 24 of the control device 2 and input to the CPU 3. The CPU 3 switches the switching circuit from the temporary touch switch 120 to the temporary touch switch 121, the temporary touch switch 122, the temporary touch switch 123, and the temporary touch switch 124 in this order via the switch selection 27 and the switch selection 26. 8 and the switching circuit 13 are sequentially controlled to input digital data.

FIG. 4 is a waveform diagram of the multiplication circuits 19 and 20 when measuring the on / off state of the touch switch according to the first embodiment. A sin signal or a cos signal is input to the X inputs of the multiplication circuits 19 and 20. One side of the resistor 14 is set to VGND. The Y inputs of the multiplication circuits 19 and 20 on the opposite side are connected to the switch electrodes 101 and 102 of the switch electrode group A10 that constitutes a touch switch in which the sin signal that has passed through the amplifier circuit 7 is connected to the drive line via the switching circuit 8. The switch electrodes 111 and 112 of the pair of switch electrodes B11 are connected via the switching circuit 13.
For example, when a human finger approaches the temporary touch switch 121 including the switch electrode 101 of the connected switch electrode group A10 and the switch electrode 111 of the switch electrode group B11, the current i1 connects the drive lines. A current flows from the switch electrode 101 of the switch electrode group A10 through a finger or the like to change, and the potential difference E1 changes at both ends of the resistor 14, and is input to Y of the multiplication circuits 19 and 20.
The X and Y input signals of the multiplication circuits 19 and 20 are multiplied, and only the AC signal of the true current value becomes a double AC frequency including the DC signal, and the DC signal is passed through the next low-pass filters 21 and 22. become. Even if noise, which is another frequency component, is mixed in the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 121, all the frequencies of the noise are sin signals and cos signals. As a result of the multiplication, an AC signal having a frequency higher than the frequency of the sin signal / cos signal is obtained, and the AC signal can be eliminated by passing the low-pass filters 21 and 22 sufficiently lower than the frequency of the sin signal / cos signal. In this way, it can be grasped that a human finger is approaching the temporary touch switch 121.

FIG. 5 shows the input signal level and phase difference diagram of the present invention. The input signal multiplied by the sin signal in the multiplication circuits 19 and 20 in FIG. 4 becomes a detection signal by sin, and the input signal multiplied by the cos signal becomes a detection signal by cos. Here, in the initialization state such as when the power is turned on, the switch electrodes 111 and 112 of the switch electrode group B11 paired with the switch electrodes 101 and 102 of the switch electrode group A10 constituting the temporary touch switches 121 to 124 are designated. The low-pass filters 21 and 22 represent the detection signal x obtained by multiplying the cosin signal with the detection signal y obtained by multiplying the sin signal in a state where no hand or the like is in contact with the water drop. Through the A / D converters 23 and 24, and the measured digital data is measured. In particular, a measured value in an initialization state such as when the power is turned on is called a base value. A sin signal side of the base value is a y_base value, and a cos signal side is an x_base value. When measurement is performed, the difference between the measured value of the input signal and the base value on the sin side y_dt, the difference on the cos side from the detection signal x obtained by multiplication with the sin signal at that time and the cos signal. Find x_dt. y_dt is (y-y_base), and x_dt is (xx-base).
From this, the change amount dt is calculated as an equation route (the square of (y−y_base) + the square of (xx−base)). The phase difference is obtained from the formula arctangent ((y-y_base) / (xx_base)). In FIG. 5, when x_base and y_base are the origins, a water drop is not placed and a finger is in contact is indicated by a solid line arrow. The detection signal on the sin signal side at this time is the detection signal on the y1 and cosine signal side. The detection signal is represented as x1. Further, when the water drop is placed and the finger is not in contact, the broken line arrow is indicated, and the detection signal on the sin signal side at this time is indicated as y2, and the detection signal on the cos signal side is indicated as x2. Then, when x_base and y_base are used as the origin, detection signals x1 and y1 when a water drop is not placed and a finger is in contact, and detection signals x2 and y2 when a water drop is placed and a finger is not in contact And indicate that the direction is different. In addition, the detection signal when the water droplet is placed and the finger is in contact is the same as the detection signals x1 and y1 when the water droplet is not placed and the finger is in contact when the origin is x_base and y_base. In terms of directionality, the amount of change in the input signal tends to be large.
From these facts, obtaining and using the measurement value and phase difference of the input signal is a very effective means for detecting the position coordinates and the like where accuracy is required.

  FIG. 6 shows a sin signal multiplication waveform diagram. Multiplying a · sin α and b · sin α yields (a · sin α) · (b · sin α) = (a · b / 2) − (a · b · cos 2α) / 2, where only a · b / 2. Where added, there is a cos signal that is half the frequency doubled. If this calculation result passes through the low-pass filter 21 or 22 having a sufficiently low value, the cos signal becomes 0, and only a constant of a · b / 2 is obtained. Even if a noise frequency other than the frequency of a · sin α is mixed according to this equation, the noise frequency is cut and the influence of the noise frequency is eliminated.

  FIG. 7 shows the relationship between the switch electrode of the temporary touch switch 121 and a human finger when no water is placed on the touch switch 1 and the touch switch 2. The switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 that do not contribute to the configuration of the temporary touch switch 121 are connected to VGND. In FIG. 7, 1) is a case where the finger is farther from the switch electrode constituting the temporary touch switch 121 via the PET film 9. Even if a human finger is separated from the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 that constitute the temporary touch switch 121, the finger is between the switch electrode 101 of the switch electrode group A10. Although capacitance is generated, the capacitance is very small. Therefore, since the current Δi hardly flows from the switch electrode 101 of the switch electrode group A10 to the ground via the finger, the voltage of the sin signal supplied to the switch electrode 101 of the switch electrode group A10 connected to the drive line. Is directly transmitted to the switch electrode 111 of the switch electrode group B11. The current i ′ of the switch electrode 111 of the switch electrode group B11 at this time is a value obtained by subtracting the lost current Δi from the current i of the switch electrode 101 of the switch electrode group A11. The signal that has passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and band-pass filter circuit 17 is used as the base value.

  2) in FIG. 7 is a case where the finger approaches or touches the vicinity of the touch switch 1. Capacitance is generated between a human finger and the switch electrode 101 of the switch electrode group A10 constituting the temporary touch switch 121 via the PET film 9, and a current Δi is generated from the switch electrode 101 of the switch electrode group A10. , And the current Δi is lost, so that the voltage of the sin signal at the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is smaller than 1) in FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine signal and the cosine signal via the subsequent amplifier circuit 16 and bandpass filter circuit 17 become smaller than 1) in FIG.

FIG. 8 shows a relationship between the switch electrode of the temporary touch switch 121 and a human finger when the touch switch 1 has water placed thereon and the touch switch 2 has no water placed thereon. Water is placed through the PET film 9 on the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 121. 8) shows a case where the finger is farther from the switch electrode constituting the temporary touch switch via the PET film 9. FIG. Even if a human finger is separated from the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 that constitute the temporary touch switch 121, the finger is between the switch electrode 101 of the switch electrode group A10. Although capacitance is generated, the capacitance is very small. Therefore, since the current Δi hardly flows from the switch electrode of the switch electrode group A10 to the ground through the finger, the voltage of the sin signal supplied to the switch electrode 101 of the switch electrode group A10 connected to the drive line is Then, it is transmitted to the switch electrode 111 of the switch electrode group B11 as it is. However, water is placed between the switch electrode 101 and the switch electrode 111, and the relative permittivity of the water is about 80, whereas in FIG. Air, which has a relative dielectric constant of about 1. Therefore, the voltage of the switch electrode 111 of the switch electrode group B11 increases from 1) in FIG. 7, and the current also increases. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and bandpass filter circuit 17 become larger than 1) in FIG.
A similar tendency is that the relative permittivity is larger than air, ice 4.2, sand 3.0-5.0, flour 2.5-3.0, paper 2.0-2.5, petroleum 2.0- 2.2 mag also appears. Further, when a metal that is a conductor, for example, a copper coin is placed on the switch electrode 101 and the switch electrode 111, the copper coin serves as a connection, and as a result, the switch electrode 101 and the switch forming a capacitor. The distance between the electrodes 111 is reduced in a pseudo manner, so that the voltage of the switch electrode 111 of the switch electrode group B11 increases from 1) in FIG. 7, and the current also increases.

  8) is a case where the finger approaches or touches the vicinity of the touch switch 1. FIG. Capacitance is generated between the human finger and the switch electrode 101 of the switch electrode group A10 constituting the temporary touch switch 121 via the PET film 9, and the current Δi is applied to the finger from the switch electrode 101 of the switch electrode group A10. Since the current Δi is lost by flowing from the water droplets to the ground through the finger, the voltage of the sin signal is switched between the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11. 7 of 1) and 2) of FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and bandpass filter circuit 17 become smaller than 1) in FIG. 7 and 2) in FIG.

FIG. 9 shows the relationship between the finger of the temporary touch switch 121 and the switch electrode in a state where water is placed on the touch switch 1 and the touch switch 2.
Switch electrode 101 of switch electrode group A10 and switch electrode 111 of switch electrode group B11 constituting temporary touch switch 121, and switch electrode 102 and switch of switch electrode group A10 not contributing to the configuration of temporary touch switch 121 The electrode group B11 is placed on the switch electrode 112 across the PET film 9 across the water. FIG. 9 1) shows a case where the finger is farther from the switch electrode constituting the temporary touch switch via the PET film 9. Even if a human finger is separated from the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 that constitute the temporary touch switch 121, the finger is between the switch electrode 101 of the switch electrode group A10. Although capacitance is generated, the capacitance is very small.

  However, since the switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 that do not contribute to the configuration of the temporary touch switch 121 are connected to VGND, the temporary touch switch 121 is connected via water. Between the switch electrode 101 of the switch electrode group A10 that constitutes the switch electrode 102, the switch electrode 102 of the switch electrode group A10 that does not contribute to the configuration of the temporary touch switch 121, and the switch electrode 112 of the switch electrode group B11. Is generated and flows from the switch electrode 101 of the switch electrode group A10 to VGND via the switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 that do not contribute to the configuration of the temporary touch switch 121. , The current Δi is lost. Therefore, the voltage of the sin signal at the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is smaller than 1) in FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine signal and the cosine signal via the subsequent amplifier circuit 16 and bandpass filter circuit 17 become smaller than 1) in FIG.

FIG. 9 2) shows a case where the finger approaches or touches the vicinity of the touch switch 1. Capacitance is generated between the human finger and the switch electrode 101 of the switch electrode group A10 constituting the temporary touch switch 121 via the PET film 9, and the current Δi is applied to the finger from the switch electrode 101 of the switch electrode group A10. Flows to the earth through the water, and also flows from the water to the earth through the fingers, losing current. Furthermore, the switch electrode 101 of the switch electrode group A10 that constitutes the temporary touch switch 121 and the switch electrode 102 and the switch electrode group B11 of the switch electrode group A10 that do not contribute to the configuration of the temporary touch switch 121 via water. Capacitance is generated between the switch electrode 112 and a current flows to VGND connected to the switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11, so that the current is lost. Since these currents Δi are lost, the voltage of the sin signal at the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is smaller than 1) of FIG. 7 and 2) of FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and bandpass filter circuit 17 become smaller than 1) in FIG. 7 and 2) in FIG. Note that 2) in FIG. 9 describes the temporary touch switch 121 when the finger approaches or touches the vicinity of the touch switch 1, but the finger approaches or touches the vicinity of the touch switch 2. Even in this case, since water is placed across the touch switches 1 and 2, the operation is the same as that of the temporary touch switch 121.

  7, 8, and 9, the temporary touch switch 121 has been described. However, the temporary touch switch 122 operates in the same manner as the temporary touch switch 121.

FIG. 10 shows the relationship between the finger of the temporary touch switch 123 and the switch electrode when no water is placed on the touch switch 1 and the touch switch 2. The switch electrode 112 of the switch electrode group B11 that does not contribute to the configuration of the temporary touch switch 123 is connected to VGND.
10 shows a case where the finger is farther than the switch electrode constituting the temporary touch switch 123 via the PET film 9. Even if a human finger is separated from the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 123, the switch electrodes 101 and 102 of the switch electrode group A10 are separated from the fingers. Capacitance is generated between the two, but the capacitance is very small. For this reason, since the current Δi hardly flows from the switch electrodes 101 and 102 of the switch electrode group A10 to the ground via the finger, the current Δi is supplied to the switch electrodes 101 and 102 of the switch electrode group A10 connected to the drive line. The voltage of the sin signal is transmitted to the switch electrode 111 of the switch electrode group B11 as it is. At this time, the current i ′ of the switch electrode 111 of the switch electrode group B11 is a value obtained by subtracting the lost current Δi from the current i of the switch electrodes 101 and 102 of the switch electrode group A11. The signal that has passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and band-pass filter circuit 17 is used as the base value.

  2) in FIG. 10 is a case where the finger approaches or touches the vicinity of the touch switch 1. Capacitance is generated between the human finger and the switch electrodes 101 and 102 of the switch electrode group A10 constituting the temporary touch switch 123 via the PET film 9, and the current Δi is changed to the switch electrode 101 of the switch electrode group A10. , 102 flows to the ground through a finger and loses the current Δi, so that the voltage of the sin signal at the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is as shown in 1) of FIG. Decrease. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and band-pass filter circuit 17 are smaller than 1) in FIG.

  FIG. 11 shows the relationship between the finger of the temporary touch switch 123 and the switch electrode when the touch switch 1 has water placed thereon and the touch switch 2 has no water placed thereon. Water droplets are placed on the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 123 via the PET film 9. 11 shows a case where the finger is farther than the switch electrode constituting the temporary touch switch via the PET film 9. Even if a human finger is separated from the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 123, the switch electrodes 101 and 102 of the switch electrode group A10 are separated from the fingers. A capacitance is generated between the two, but the capacitance is very small. For this reason, since the current Δi hardly flows from the switch electrode of the switch electrode group A10 to the ground via the finger, the sin signal supplied to the switch electrodes 101 and 102 of the switch electrode group A10 connected to the drive line The voltage is transmitted as it is to the switch electrode 111 of the switch electrode group B11. However, water is placed between the switch electrode 101 and the switch electrode 111, and the relative permittivity of the water is about 80, whereas in FIG. Air, which has a relative dielectric constant of about 1. Therefore, the voltage of the switch electrode 111 of the switch electrode group B11 increases from 1) in FIG. 10, and the current also increases. The signals that have passed through the multiplication circuits 19 and 20 with the sine signal and the cosine signal via the subsequent amplifier circuit 16 and band-pass filter circuit 17 become larger than 1) in FIG.

2) in FIG. 11 is a case where the finger approaches or comes into contact with the switch electrode constituting the temporary touch switch via the PET film 9. A capacitance is generated between the human finger and the switch electrodes 101 and 102 of the switch electrode group A10 constituting the temporary touch switch 123, and the current Δi is passed from the switch electrodes 101 and 102 of the switch electrode group A10 via the finger. Since it flows to the ground and flows from the water droplets to the ground through the finger and loses the current Δi, the voltage of the sin signal at the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is It is reduced from 1) of 10 and 2) of FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and bandpass filter circuit 17 become smaller than 1) in FIG. 10 and 2) in FIG.
The temporary touch switch 124 operates in the same manner as the temporary touch switch 123.

FIG. 12 shows the relationship between the finger of the temporary touch switch 123 and the switch electrode when water is placed on the touch switch 1 and the touch switch 2.
Switch electrodes 101 and 102 of switch electrode group A10 and switch electrode 111 of switch electrode group B11 constituting temporary touch switch 123, and switch electrode 112 of switch electrode group B11 not contributing to the configuration of temporary touch switch 121 It is placed across the water via the PET film 9. FIG. 12 1) shows a case where the finger is farther from the switch electrode constituting the temporary touch switch via the PET film 9. Even if a human finger is separated from the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 121, the finger is placed between the switch electrode 101 of the switch electrode group A10. Has a capacitance, but the capacitance is very small.

  However, since the switch electrode 112 of the switch electrode group B11 that does not contribute to the configuration of the temporary touch switch 123 is connected to VGND, the switch of the switch electrode group A10 that configures the temporary touch switch 123 via water. Capacitance is generated between the electrodes 101 and 102 and the switch electrode 112 of the switch electrode group B11 that does not contribute to the configuration of the temporary touch switch 123, and a current Δi is temporarily generated from the switch electrode 101 of the switch electrode group A10. Flows out to VGND via the switch electrode 112 of the switch electrode group B11 that does not contribute to the configuration of the touch switch 121, and the current Δi is lost. However, as compared with 2) in FIG. 9, since the number of electrodes of VGND is small and the number of electrodes to be driven is large, the voltage of the switch electrode 111 of the switch electrode group B11 increases from 1) of FIG. Will also increase. The signals that have passed through the multiplication circuits 19 and 20 with the sine signal and the cosine signal via the subsequent amplifier circuit 16 and band-pass filter circuit 17 become larger than 1) in FIG.

  2) of FIG. 12 is a case where the finger approaches or touches the vicinity of the touch switch 1. Capacitance is generated between the switch electrodes 101 and 102 of the switch electrode group A10 constituting the temporary touch switch 123 via the human finger and the PET film 9, and the current Δi is changed to the switch electrode 101 of the switch electrode group A10. The current flows from 102 to the ground through the finger and from the water droplets to the ground through the finger to lose the current. Furthermore, between the switch electrodes 101 and 102 of the switch electrode group A10 constituting the temporary touch switch 123 and the switch electrode 112 of the switch electrode group B11 not contributing to the configuration of the temporary touch switch 123 via water. Capacitance is generated and a current flows to VGND connected to the switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11, so that the current is lost. Since these currents Δi are lost, the voltage of the sin signal at the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is reduced from 1) in FIG. 10 and 2) in FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and bandpass filter circuit 17 become smaller than 1) in FIG. 10 and 2) in FIG. Note that 2) in FIG. 12 describes the temporary touch switch 123 when the finger approaches or touches the vicinity of the touch switch 1, but the finger approaches or touches the vicinity of the touch switch 2. Even in this case, since water is placed across the touch switches 1 and 2, the operation is the same as the description of the temporary touch switch 121.

10, 11, and 12, the temporary touch switch 123 has been described. However, the temporary touch switch 124 operates in the same manner as the temporary touch switch 123.
Here, the current i ′ of the temporary touch switches 121 to 124 when the touch switch 1 and the touch switch 2 are touched with no metal placed on the hand and touching the touch switch 1 and the touch switch 2 is measured in advance. At this time, the normalized value is stored in the EEPROM 32 in advance as a reference change amount and the phase difference at that time as a reference phase difference. Similarly, the normalized value when there is no noise of the same frequency as the sin signal and cos signal of the touch switch 120 is stored in the EEPROM 32 in advance as a reference change amount, and the phase difference at that time is also a reference phase difference.
In addition, the current i ′ when the finger is not touching the temporary touch switches 121 to 124 without water is measured in advance, and the current i ′ when the finger is touched is measured by the temporary touch switches 121 to 124. The amount of change in the current that is turned on is measured, and the normalized value at this time is stored in the EEPROM 32 in advance as a threshold value. Similarly, the normalized value when there is noise of the same frequency as the sin signal and cos signal of the touch switch 120 is stored in the EEPROM 32 in advance as a reference change amount, and the phase difference at that time is also a reference phase difference.

Further, the current i ′ when there is no water placement and a human finger does not touch the temporary touch switches 121 to 124 is measured in advance, and the current i ′ when there is water placement is temporarily measured. The amount of change in current that causes the touch switch 121 to be placed on the water is measured, and the normalized value at this time is stored in the EEPROM 32 in advance as a threshold value.
7 to 12, a table corresponding to the touch switch 1 and the touch switch 2 is shown in FIG. FIG. 13 shows the operation status of the temporary touch switches 121 to 124 depending on whether water is placed on the touch switch 1 and the touch switch 2 or a finger is touched. Then, based on the operation pattern of the temporary touch switches 121 to 124, the control flow of the first embodiment is performed to transmit the notification information of the state of the touch switch 1 and the touch switch 2 to the external processing device 31. Can do.

A control flow will be described with reference to FIGS.
14 shows a main control flow of the first embodiment, FIG. 15 shows an interrupt flow of the timer of the first embodiment, and FIG. 16 shows the same frequency as that of the sin signal and the cos signal in the temporary touch switch 120. FIG. 17 shows a calculation processing flow of the temporary touch switch 121, and FIG. 18 generates the states of the touch switch 1 and the touch switch 2 from the states of the temporary touch switches 121 to 124. FIG. 19 shows an output processing flow of the state of the touch switch 1 and the touch switch 2 to the external processing device. FIG. 20 shows the RAM 29 and the EEPROM 32 used in FIGS. Represents the memory being allocated.

First, the main control flow of FIG. 14 will be described.
Here, ON and OFF threshold values SW0_threshold1 to SW4_threshold1 corresponding to the temporary touch switches 120 to 124, OFF and water mounting threshold values SW0_threshhold2 to SW4_threshold2, reference change amounts SW0_scale to SW4_scale, reference phase differences SW0_de and g to SWg_de. Is stored in the EEPROM in advance, and counter data Count_data and the frequency HZ to be held for a predetermined time are stored in the EEPROM in advance. Then, this control flow is started. An external processing device 31, for example, an external I / F 30 connected to the host is initialized, the oscillation frequency data stored in the frequency HZ of the EEPROM 32 is set in the oscillator 4, and a bandpass filter circuit corresponding to the oscillation frequency data 17. Set via switch selection 25 and set timer 33 as interval timer (S1) (S represents step). Then, the flags Touch1_stat to Touch2_stat indicating the state of the touch switches 1 and 2 arranged on the RAM 29 are set to 0 to be in the OFF state, and the flag SW1_stat indicating the switch state of the temporary touch switches 121 to 124 is set. Set SW4_stat to 0 to turn it off, touch switches 1 and 2 that count the elapsed time of a timer that holds the water placement state of touch switches 1 and 2 and the placement state of water straddling for a certain period of time. Corresponding Count1 and Count2 are set to 0 (S2).
Next, in order to measure the digital data of the temporary touch switch 120, the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 121 is turned on, and the other switch electrodes are turned off via the switch selection 27. The switching circuit 8 is set and the switching circuit 13 is set via the switch selection 26. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. It is stored as a base value in SW0_y_base and SW0_x_base (S3).
Next, in order to measure the digital data of the temporary touch switch 121, the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 121 are turned on, and the other switch electrodes are turned off. As described above, the switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. It is stored as a base value in SW1_y_base and SW1_x_base (S4).

  Similarly, in order to measure the digital data of the temporary touch switch 122, the switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 constituting the temporary touch switch 122 are turned on, and the other switch electrodes are turned off. As described above, the switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. It is stored as a base value in SW2_y_base and SW2_x_base (S5).

  Similarly, in order to measure digital data of the temporary touch switch 123, the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 123 are turned on, and the other switch electrodes. The switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26 so as to be turned off. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. It is stored as a base value in SW3_y_base and SW3_x_base (S6).

Similarly, in order to measure the digital data of the temporary touch switch 124, the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 constituting the temporary touch switch 124 are turned on, and the other switch electrodes. The switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26 so as to be turned off. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. It is stored as a base value in SW4_y_base and SW4_x_base (S7).
Steps 3 to 7 are calibration periods of the present capacitive coupling type electrostatic sensor. At this time, the finger is not in contact with the switch electrode of each temporary touch switch, and water is loaded. Leave it out of place.
Next, in order to measure the digital data of the temporary touch switch 120, the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 120 is turned on, and the other switch electrodes are turned off via the switch selection 27. The switching circuit 8 is set and the switching circuit 13 is set via the switch selection 26. Then, the digital data via the A / D converter 23 measured with the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured with the cos signal of the oscillator 4 are stored on the RAM 29. The measured values are stored in SW1_y and SW1_x (S8).
Similarly, in order to measure the digital data of the temporary touch switch 121, the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 121 are turned on, and the other switch electrodes are turned off. As described above, the switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. The measured values are stored in SW1_y and SW1_x (S9).

  Similarly, in order to measure the digital data of the temporary touch switch 122, the switch electrode 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 constituting the temporary touch switch 122 are turned on, and the other switch electrodes are turned off. As described above, the switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. The measured values are stored in SW2_y and SW2_x (S10).

  Similarly, in order to measure digital data of the temporary touch switch 123, the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 constituting the temporary touch switch 123 are turned on, and the other switch electrodes. The switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26 so as to be turned off. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. The measured values are stored in SW3_y and SW3_x (S11).

  Similarly, in order to measure the digital data of the temporary touch switch 124, the switch electrodes 101 and 102 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 constituting the temporary touch switch 124 are turned on, and the other switch electrodes. The switching circuit 8 is set via the switch selection 27 and the switching circuit 13 is set via the switch selection 26 so as to be turned off. Then, the digital data via the A / D converter 23 measured by the sin signal of the oscillator 4 and the digital data via the A / D converter 24 measured by the cos signal of the oscillator 4 are stored on the RAM 29. The measured values are stored in SW4_y and SW4_x (S12).

Then, noise processing of the temporary touch switch 120 is performed (S13). This noise processing will be described in detail later, but the amount of change from the measured value and the base value is calculated and further normalized to determine whether the sin signal and the cos signal contain noise at the same frequency, and the same as that signal. In some cases, change to a different frequency. (S13)
Then, calculation processing of the temporary touch switch 121 is performed (S14). This calculation process will be described in detail later. Calculation of the amount of change from the measured value and the base value, normalization of the amount of change in which the directionality is set, and the temporary touch switch 121 corresponding to each threshold value being in the ON state , OFF state and water mounting state are set.

  Similarly, calculation processing of the temporary touch switch 122 is performed (S15). Since the arithmetic processing method of the temporary touch switch 121 is equivalent, the description is omitted.

  Similarly, calculation processing of the temporary touch switch 123 is performed (S16). Since the arithmetic processing method of the temporary touch switch 121 is equivalent, the description is omitted.

Similarly, calculation processing of the temporary touch switch 124 is performed (S17). Since the arithmetic processing method of the temporary touch switch 121 is equivalent, the description is omitted.
And the state process which produces | generates the state to the touch switches 1 and 2 from the touch ON of the temporary touch switches 121-124, the touch OFF, and the state of water mounting is performed (S18).
From the result of step 18, an output process for outputting the state of the touch switches 1 and 2 to the external processing device 31 is performed (S19). After the output process, the process returns to step 8.

Next, the interrupt flow of the timer according to the first embodiment shown in FIG. 15 will be described.
The counts of Count1 and Count2 corresponding to the touch switches 1 and 2 that count the elapsed time of the timer that holds the water placement state of the touch switches 1 and 2 and the placement state that the water straddles for a certain period of time are counted down every unit time. . First, if Count1 is 0 or more (S20), Count1 is counted down by one (S21), and the process proceeds to step 22. If Count1 is less than 0 in Step 20, the process proceeds to Step 22. In Step 22, if Count2 is 0 or more (S20), Count2 is counted down by one (S23), and the interrupt process is terminated. In step 22, if Count2 is less than 0, the interrupt process is terminated.

  Next, referring to FIG. 16, a flow of frequency switching when noise having the same frequency as that of the sin signal and the cos signal in the temporary touch switch 120 is mixed will be described. First, the difference SW0_y_dt between the measured value SW0_y on the sine side and the base value SW0_y_base and the difference SW0_x_dt between the measured value SW0_x on the cos side and the base value SW0_x_base are obtained. ) And the normalized value SW0_normal, the change amount SW0_dt is divided by the reference change amount SW1_scale, further multiplied by 100 and stored as a percentage (S24). When the normalized value SW0_normal exceeds the threshold value SW0_threshold1 (S25), it is determined that there is noise mixing with the same frequency as the frequency of the sin signal and the cos signal, and switching of the oscillation frequency of the oscillator 4 and corresponding to the oscillation frequency The band pass filter of the band pass filter circuit 17 is switched via the switch selection 25 (S26), and the noise processing is terminated. When the normalized value SW0_normal is equal to or smaller than the threshold value SW0_threshold1 (S25), the noise processing is terminated.

  Next, FIG. 17 illustrates a flow for setting the touch ON state, the OFF state, and the water placement state in the temporary touch switch 120.

  First, the difference SW1_y_dt between the measured value SW1_y on the sine side and the base value SW1_y_base and the difference SW1_x_dt between the measured value SW1_x on the cos side and the base value SW1_x_base are obtained. ) And the normalized value SW1_normal is divided by the change amount SW1_dt by the reference change amount SW1_scale, further multiplied by 100 and stored as a percentage (S27). If the difference SW1_x_dt is 0, the process proceeds to step 30; otherwise, the process proceeds to step 29 (S28). In step 29, the phase difference SW1_theta is obtained from the formula arctangent (SW1_y_dt / SW1_x_dt) and the process proceeds to step 34.

  Here, if the difference SW1_y_dt is 0 in step 30, the touch is turned off and the process proceeds to step 37. Otherwise, the process proceeds to step 31. In step 31, if the difference SW1_y_dt is 0 or more, the phase difference SW1_theta is set to 90 °, and if it is less than 0, it is set to 270 ° and the process proceeds to step 34.

  In step 34, if the phase difference SW1_theta is within ± 90 ° of the reference phase difference SW1_deg, the process proceeds to step 35 for making a touch determination. If the phase difference SW1_theta is other than ± 90 ° of the reference phase difference SW1_deg, water is placed. Proceed to step 39 for determination.

  In step 35, the normalized value SW1_normal is converted into a negative value. If SW1_normal is larger than the threshold value SW1_threshold1, it is determined that the touch is OFF, and SW1_stat is set to 0 (S37). If SW1_normal is equal to or lower than the threshold value SW1_threshold1, the touch is determined to be ON, 1 is set (S38), and the calculation process is terminated.

  In step 39, when SW1_normal is equal to or larger than the threshold SW1_threshold2, it is determined that the water is placed, and SW1_stat is set to 2 (S40). SW1_stat is set to 0 (S41), and the calculation process is terminated.

  Next, FIG. 18 illustrates a flow of state processing for generating the states of the touch switch 1 and the touch switch 2 from the states of the temporary touch switches 121 to 124.

  First, in step 42, SW1_stat of temporary touch switch 121 and SW2_stat of temporary touch switch 122 are both other than 2, that is, other than water placement, SW3_stat of temporary touch switch 123 and SW4_stat of temporary touch switch 124. However, when both are 2, that is, in the case of the water mounting state, the process proceeds to step 43 as the water mounting state across the touch switches 1 and 2. In step 43, the state Touch1_stat of the touch switch 1 is set to 6 and the state Touch2_stat of the touch switch 2 is set to 6 so as to be in the water-mounted state. The counters for holding the fixed time for the counters Count1 and Count2 Data Count_data is set (S44), and the state processing is terminated.

  If it is determined in step 42 that the state is other than the water placement state across the touch switches 1 and 2, the process proceeds to step 45. In step 45, SW1_stat of the temporary touch switch 121 and SW2_stat of the temporary touch switch 122 are both 1, that is, in the ON state, Touch1_stat of the touch switch 1 and Touch2_stat of the touch switch 2 are both 6, that is, straddle. In the state of water mounting, the touch switches 1 and 2 are turned on by water mounting, and the process proceeds to step 46. In step 46, 7 is set in Touch1_stat of touch switch 1 and 7 is set in Touch2_stat of touch switch 2, and the touch switch is turned on by placing on the water, and the counters Count1 and Count2 are held for a fixed time. The counter data Count_data is set (S47), and the state processing is terminated.

  If it is determined in step 45 that the touch switches 1 and 2 are not in the ON state due to water placement, the process proceeds to step 48. In step 48, when SW1_stat of the temporary touch switch 121 is 2, that is, in the water-mounted state, Touch1_stat of the touch switch 1 is set to 2 (S49), and the constant time holding counter Count1 is held for a fixed time. The counter data Count_data is set (S50), and the process proceeds to step 55.

  In step 48, when SW1_stat of the temporary touch switch 121 is other than 2, the process proceeds to step 51. In step 51, when SW1_stat of the temporary touch switch 121 is 1, that is, in the ON state, 1 is set to Touch1_stat of the touch switch 1 and set, and the past water state is also reflected. In step S52, the process proceeds to step 55.

  In step 51, when SW1_stat of the temporary touch switch 121 is other than 1, the process proceeds to step 53. When the temporary touch switch 121 is in the OFF state and the constant time holding counter Count1 is 0, Touch1_stat of the touch switch 1 is set to 0 (S54), and the process proceeds to step 55. If it is determined in step 54 that the constant time holding counter Count1 is other than 0, the process proceeds to step 55.

  In step 55, when SW2_stat of the temporary touch switch 122 is 2, that is, in the water-mounted state, Touch2_stat of the touch switch 2 is set to 2 (S56), and the constant time holding counter Count2 is held for a fixed time. The counter data Count_data is set (S57), and the state processing is terminated.

  If it is determined in step 55 that SW2_stat of the temporary touch switch 122 is other than 2, the process proceeds to step 58. In step 58, when SW2_stat of the temporary touch switch 122 is 1, that is, in the ON state, 1 is set in the Touch2_stat of the touch switch 2 to set it to reflect the past water state. (S59), and the state process ends.

  If it is determined in step 58 that SW2_stat of the temporary touch switch 122 is other than 1, the process proceeds to step 60. When the temporary touch switch 122 is in the OFF state and the constant time holding counter Count2 is 0, Touch2_stat of the touch switch 2 is set to 0 (S61), and the state process is terminated. In step 60, when the fixed time holding counter Count2 is other than 0, the state processing is terminated.

  Next, the state of the touch switch 1 and the touch switch 2 will be described with reference to FIG.

  In step 62, when the state Touch1_stat of the touch switch 1 is 0, a state in which the touch switch 1 is OFF is output to the external processing device 31 (S63), and the process proceeds to step 74.

  In step 62, when the state Touch1_stat of the touch switch 1 is other than 0, the process proceeds to step 64. In step 64, when the state Touch1_stat of the touch switch 1 is 1, the state in which the touch switch 1 is ON is output to the external processing device 31 (S65), and the process proceeds to step 74.

  In step 64, when the state Touch1_stat of the touch switch 1 is other than 1, the process proceeds to step 66. In step 66, when the state Touch1_stat of the touch switch 1 is 2, the touch switch 1 outputs the water placement state to the external processing device 31 (S67), and proceeds to step 74.

  If it is determined in step 66 that the state Touch1_stat of the touch switch 1 is other than 2, the process proceeds to step 68. In Step 68, when the state Touch1_stat of the touch switch 1 is 3, the touch switch 1 is placed on the water and the touch ON state is output to the external processing device 31 (S69), and the process proceeds to Step 74.

  In step 68, when the state Touch1_stat of the touch switch 1 is other than 3, the process proceeds to step 70. In step 70, when the state Touch1_stat of the touch switch 1 is 6, the touch switch 1 straddles and outputs the water placement state to the external processing device 31 (S71), and proceeds to step 74.

  In step 70, when the state Touch1_stat of the touch switch 1 is other than 6, the process proceeds to step 72. In step 72, when the state Touch1_stat of the touch switch 1 is 7, the touch switch 1 is straddled and the touch-on state is output to the external processing device 31 with water mounted (S73), and the process proceeds to step 74.

  In step 72, when the state Touch1_stat of the touch switch 1 is other than 7, the process proceeds to step 74.

  In step 74, when the state Touch2_stat of the touch switch 2 is 0, a state in which the touch switch 2 is OFF is output to the external processing device 31 (S75), and the output process is terminated.

  In step 74, when the state Touch2_stat of the touch switch 2 is other than 0, the process proceeds to step 76. In step 76, when the state Touch2_stat of the touch switch 2 is 1, the state in which the touch switch 2 is ON is output to the external processing device 31 (S77), and the output process is terminated.

  In step 76, when the state Touch2_stat of the touch switch 2 is other than 1, the process proceeds to step 78. In step 78, when the state Touch2_stat of the touch switch 2 is 2, the touch switch 2 outputs the water placement state to the external processing device 31 (S79), and the output process is terminated.

  In step 78, when the state Touch2_stat of the touch switch 2 is other than 2, the process proceeds to step 80. In step 80, when the state Touch2_stat of the touch switch 2 is 3, the touch switch 2 is placed on the water and the touch ON state is output to the external processing device 31 (S81), and the output process is terminated.

  In step 80, when the state Touch2_stat of the touch switch 2 is other than 3, the process proceeds to step 82. In step 82, when the state Touch2_stat of the touch switch 2 is 6, the water switch state is output to the external processing device 31 across the touch switch 2 (S83), and the output process is terminated.

  In step 82, when the state Touch2_stat of the touch switch 2 is other than 6, the process proceeds to step 84. In step 84, when the state Touch2_stat of the touch switch 2 is 7, the touch switch 2 is placed across the water and the touch ON state is output to the external processing device 31 (S85), and the output process is terminated.

  In step 84, when the state Touch2_stat of the touch switch 2 is other than 7, the output process is terminated.

  Next, a second embodiment will be described.

  In the first embodiment, the configuration of the temporary touch switch 123 includes the switch electrode 101 and the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11, and the configuration of the temporary touch switch 124 includes the switch electrode. The switch electrode 101 and the switch electrode 102 of the group A10, and the switch electrode 112 of the switch electrode group B11 are included. In the second embodiment, the configuration of the temporary touch switch 123 is a pair of the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11, and the configuration of the temporary touch switch 124 is the switch electrode. A case where the switch electrode 101 of the group A10 and the switch electrode 112 of the switch electrode group B11 are paired will be described.

Here, the configuration diagram of the second embodiment is equivalent to the configuration diagram of FIG. 1 of the first embodiment, and the schematic diagram of the touch switch of the second embodiment is the touch of FIG. 2 of the first embodiment. It is equivalent to the schematic diagram of the switch, the multiplication circuit waveform diagram of the second embodiment is also equivalent to the multiplication circuit waveform diagram of FIG. 4 of the first embodiment, and the input signal level and phase difference diagram of the second embodiment are This is equivalent to the input signal level and phase difference diagram of FIG. 5 of the first embodiment. Further, the sin signal multiplication waveform diagram of the second embodiment is equivalent to the sin signal multiplication waveform diagram of FIG. 6 of the first embodiment, and the state of the temporary touch switch 121 of the second embodiment when no water is mounted. The figure is also equivalent to the state diagram when the temporary touch switch 121 of FIG. Further, the state diagram of the temporary touch switch 121 according to the second embodiment when the water is placed is equivalent to the state diagram of the temporary touch switch 121 of FIG. 8 according to the first embodiment when the water is placed. The state diagram when water is placed across the temporary touch switch 121 of the second embodiment is also equivalent to the state diagram when water is placed across the temporary touch switch 121 of FIG. 9 of the first embodiment. The control flow of the second embodiment is also equivalent to the control flow of FIGS. 14 to 19 of the first embodiment, and the memory configuration diagram of the second embodiment is also equivalent to FIG. 20 of the first embodiment.
Here, FIG. 21 shows switch electrodes for driving the temporary touch switches 121 to 124. In the configuration of the temporary touch switch 121, the switch electrode 101 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 are driven by a pair, and the configuration of the temporary touch switch 122 is the switch electrode of the switch electrode group A10. 102 and the switch electrode 112 of the switch electrode group B11, and the temporary touch switch 123 is driven by the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11. The temporary touch switch 124 is driven by the switch electrode 101 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11. Further, the configuration of the temporary touch switch 120 is driven only by the switch electrode 111 of the switch electrode group B11 without using the switch electrode of the switch electrode group A10.
The switch electrodes that are not used in the temporary touch switch being measured are connected to an intermediate potential (hereinafter referred to as VGND) of the sin signal or the cos signal.
Then, the switch electrode group A10 and the switch electrode group B11 are formed on the PET film 9 serving as an insulator, and the user's finger passes through the PET film 9 in the input area of the touch switch 1 and the touch switch 2. The touch or water placement can be reflected in the state of the touch switch 1 and the touch switch 2 from the state of the temporary touch switches 121 to 124 at this time (see FIG. 25). The temporary touch switch 120 measures noise having the same frequency as that of the sin signal and the cos signal mixed in the switch electrode, and when there is noise, the oscillation frequency of the oscillator 4 is switched or a band-pass filter corresponding to the oscillation frequency. Used for switching the band-pass filter of the circuit 17.

  Next, the description of the operation of the temporary touch switch 121 and the temporary touch switch 122 is equivalent to the description of FIGS. 7, 8, and 9 of the first embodiment. This will be described with reference to FIGS.

  FIG. 22 shows the relationship between the switch electrode of the temporary touch switch 123 and a human finger when no water is placed on the touch switch 1 and the touch switch 2. The switch electrode 101 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 that do not contribute to the configuration of the temporary touch switch 123 are connected to VGND. FIG. 22 1) shows a case where the finger is farther than the switch electrode constituting the temporary touch switch 123 through the PET film 9. Even if a human finger is separated from the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 that form the temporary touch switch 123, the finger is between the switch electrode 102 of the switch electrode group A10. Although capacitance is generated, the capacitance is very small. Therefore, since the current Δi hardly flows from the switch electrode 102 of the switch electrode group A10 to the ground via the finger, the voltage of the sin signal supplied to the switch electrode 102 of the switch electrode group A10 connected to the drive line. Is directly transmitted to the switch electrode 111 of the switch electrode group B11. The current i ′ of the switch electrode 111 of the switch electrode group B11 at this time is a value obtained by subtracting the lost current Δi from the current i of the switch electrode 102 of the switch electrode group A11. The signal that has passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and band-pass filter circuit 17 is used as the base value.

  FIG. 22 2) shows a case where a finger approaches or touches the vicinity of the touch switch 1. Capacitance is generated between the human finger and the switch electrode 102 of the switch electrode group A10 constituting the temporary touch switch 123 via the PET film 9, and a current Δi is generated from the switch electrode 102 of the switch electrode group A10. And the current Δi is lost, so that the voltage of the sin signal at the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is smaller than 1) in FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and bandpass filter circuit 17 are smaller than 1) in FIG.

  FIG. 23 shows a relationship between the temporary touch switch 123, the switch electrode, and a human finger when the touch switch 1 has water placed thereon and the touch switch 2 has no water placed thereon. The switch electrode 101 of the switch electrode group A10 and the temporary touch switch 123 that do not contribute to the configuration of the temporary touch switch 123 are placed with water on the switch electrode 111 of the switch electrode group B11 via the PET film 9. . FIG. 23 1) shows a case where the finger is farther from the switch electrode constituting the temporary touch switch 123 via the PET film 9. Even if a human finger is separated from the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 that form the temporary touch switch 123, the finger is between the switch electrode 102 of the switch electrode group A10. Although capacitance is generated, the capacitance is very small. Therefore, since the current Δi hardly flows from the switch electrode of the switch electrode group A10 to the ground through the finger, the voltage of the sin signal supplied to the switch electrode 102 of the switch electrode group A10 connected to the drive line is Then, it is transmitted to the switch electrode 111 of the switch electrode group B11 as it is. However, water is placed between the switch electrode 102 and the switch electrode 111, and the relative dielectric constant of the water is about 80, whereas in 1) in FIG. Air, which has a relative dielectric constant of about 1. Therefore, the voltage of the switch electrode 111 of the switch electrode group B11 increases from 1) in FIG. 22, and the current also increases.

  However, since the switch electrode 101 of the switch electrode group A10 that does not contribute to the configuration of the temporary touch switch 123 is connected to VGND, the switch of the switch electrode group A10 that configures the temporary touch switch 123 via water. Capacitance is generated between the electrode 102 and the switch electrode 101 of the switch electrode group A10 that does not contribute to the configuration of the temporary touch switch 123, and the current Δi is provisionally touched from the switch electrode 102 of the switch electrode group A10. It flows out to VGND via the switch electrode 101 of the switch electrode group A10 that does not contribute to the configuration of the switch 123, and the current Δi is lost.

Since the increase and decrease of these two currents occur, the switch electrode 101 of the switch electrode group A10 and the switch 2 of the switch electrode group B11.
The voltage of the sin signal at the switch electrode 111 is substantially the same as 1) in FIG. The signals that have passed through the multiplication circuits 19 and 20 through the subsequent amplification circuit 16 and band-pass filter circuit 17 and the sin and cos signals are substantially the same as in 1) of FIG.

  2) in FIG. 23 is a case where the finger approaches or touches the vicinity of the touch switch 1. Capacitance is generated between the human finger and the switch electrode 102 of the switch electrode group A10 constituting the temporary touch switch 123 via the PET film 9, and the current Δi is applied to the finger from the switch electrode 102 of the switch electrode group A10. Since the current Δi is lost by flowing from the water droplets to the ground via the finger, the voltage of the sin signal is switched between the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11. It is reduced from 1) of 22 and 2) of FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine signal and the cosine signal via the subsequent amplifier circuit 16 and band-pass filter circuit 17 become smaller than 1) in FIG. 22 and 2) in FIG.

FIG. 24 shows a relationship between the switch electrode of the temporary touch switch 123 and a human finger in a state where water is placed on the touch switch 1 and the touch switch 2.
Switch electrode 102 of switch electrode group A10 and switch electrode 111 of switch electrode group B11 constituting temporary touch switch 123, and switch electrode 101 and switch of switch electrode group A10 not contributing to the configuration of temporary touch switch 123 The electrode group B11 is placed on the switch electrode 112 across the PET film 9 across the water. FIG. 24 1) shows a case where the finger is farther from the switch electrode constituting the temporary touch switch via the PET film 9. Even if a human finger is separated from the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 that form the temporary touch switch 123, the finger is between the switch electrode 102 of the switch electrode group A10. Although capacitance is generated, the capacitance is very small.

  However, since the switch electrode 101 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 that do not contribute to the configuration of the temporary touch switch 123 are connected to VGND, the temporary touch switch 123 is connected via water. Capacitance between the switch electrode 102 of the switch electrode group A10 that constitutes the switch electrode 101, the switch electrode 101 of the switch electrode group A10 that does not contribute to the configuration of the temporary touch switch 123, and the switch electrode 112 of the switch electrode group B11. The generated current Δi flows from the switch electrode 102 of the switch electrode group A10 to VGND via the switch electrode 101 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11 that do not contribute to the configuration of the temporary touch switch 123. , The current Δi is lost. For this reason, the voltage of the sin signal at the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is smaller than 1) in FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sine and cos signals via the subsequent amplifier circuit 16 and bandpass filter circuit 17 are smaller than 1) in FIG.

  FIG. 24 2) shows a case where the finger approaches or touches the vicinity of the touch switch 1. Capacitance is generated between the human finger and the switch electrode 102 of the switch electrode group A10 constituting the temporary touch switch 123 via the PET film 9, and the current Δi is applied to the finger from the switch electrode 102 of the switch electrode group A10. Flows to the earth through the water, and also flows from the water to the earth through the fingers, losing the current. Furthermore, the switch electrode 102 of the switch electrode group A10 that constitutes the temporary touch switch 123 and the switch electrode 101 and the switch electrode group B11 of the switch electrode group A10 that do not contribute to the configuration of the temporary touch switch 123 via water. Capacitance is generated between the switch electrode 112 and the current flows to VGND connected to the switch electrode 101 of the switch electrode group A10 and the switch electrode 112 of the switch electrode group B11, so that the current is lost. Since these currents Δi are lost, the voltage of the sin signal at the switch electrode 102 of the switch electrode group A10 and the switch electrode 111 of the switch electrode group B11 is smaller than 1) of FIG. 22 and 2) of FIG. The signals that have passed through the multiplication circuits 19 and 20 with the sn signal and the cos signal via the subsequent amplification circuit 16 and bandpass filter circuit 17 are smaller than 1) in FIG. 22 and 2) in FIG. Note that 2) in FIG. 24 describes the temporary touch switch 123 when the finger approaches or touches the vicinity of the touch switch 1, but the finger approaches or touches the vicinity of the touch switch 2. Even in this case, since water is placed across the touch switches 1 and 2, the operation is the same as the description of the temporary touch switch 123.

In the description of FIGS. 22, 23, and 24, the temporary touch switch 123 has been described. However, the temporary touch switch 124 operates in the same manner as the temporary touch switch 123.
Here, the current i ′ of the temporary touch switches 121 to 124 when the touch switch 1 and the touch switch 2 are touched with no metal placed on the hand and touching the touch switch 1 and the touch switch 2 is measured in advance. At this time, the normalized value is stored in the EEPROM 32 in advance as a reference change amount and the phase difference at that time as a reference phase difference. Similarly, the normalized value when there is no noise of the same frequency as the sin signal and cos signal of the touch switch 120 is stored in the EEPROM 32 in advance as a reference change amount, and the phase difference at that time is also a reference phase difference.
In addition, the current i ′ when the finger is not touching the temporary touch switches 121 to 124 without water is measured in advance, and the current i ′ when the finger is touched is measured by the temporary touch switches 121 to 124. The amount of change in the current that is turned on is measured, and the normalized value at this time is stored in the EEPROM 32 in advance as a threshold value. Similarly, the normalized value when there is noise of the same frequency as the sin signal and cos signal of the touch switch 120 is stored in the EEPROM 32 in advance as a reference change amount, and the phase difference at that time is also a reference phase difference.

Further, the current i ′ when there is no water placement and a human finger does not touch the temporary touch switches 121 to 124 is measured in advance, and the current i ′ when there is water placement is temporarily measured. The amount of change in current that causes the touch switch 121 to be placed on the water is measured, and the normalized value at this time is stored in the EEPROM 32 in advance as a threshold value.
7 to 9 and 22 to 24, a table corresponding to the touch switch 1 and the touch switch 2 is shown in FIG. FIG. 25 shows the operation status of the temporary touch switches 121 to 124 depending on whether water is placed on the touch switch 1 and the touch switch 2 or a finger is touched. Then, based on the operation pattern of the temporary touch switches 121 to 124, the control flow using FIGS. 14 to 19 of the first embodiment and the configuration of FIG. Notification information about the state of the touch switch 2 can be transmitted to the external processing device 31.

1 Touch switch 2 Touch switch 3 CPU
4 Oscillator 5 Synchronous Oscillator 6 Synchronous Oscillator 7 Amplifier 8 Switch Circuit 9 PET Film 10 Switch Electrode Group A
101 Switch electrode 102 Switch electrode 11 Switch electrode group B
DESCRIPTION OF SYMBOLS 111 Switch electrode 112 Switch electrode 13 Switching circuit 14 Resistance 15 Current-voltage converter 16 Amplifier circuit 17 Band pass filter circuit 19 Multiplication circuit 20 Multiplication circuit 21 Low-pass filter 22 Low-pass filter 23 A / D converter 24 A / D converter 25 Switch Selection 26 Switch selection 27 Switch selection 28 ROM
29 RAM
30 External I / F
31 External processing device 32 EEPROM
33 Timer 34 Control device 35 Finger

Claims (6)

A plurality of switch electrodes made of a conductive material are arranged on an insulator, and a capacitance of a touch switch in which a capacitor is formed between the switch electrodes belonging to the switch electrode group A and the switch electrodes belonging to the switch electrode group B is measured . Therefore, a signal generated by an oscillator is converted into a sin signal and a cos signal synchronized by a synchronous oscillation circuit, and a switch electrode belonging to the switch electrode group A to which the sin signal is applied is selected and driven, A current / voltage conversion circuit, a wiring for selecting and connecting the switch electrodes belonging to the switch electrode group B via the current / voltage conversion circuit, a multiplication circuit for multiplying the current / voltage converted signal by the sin signal and the cos signal, a low-pass filter circuit for a signal from the multiplying circuit and a DC signal, thereby measuring the DC signal of voltage, to processing In a capacitive coupling type electrostatic sensor composed of a control device, a state where a finger or a coordinate indicator is close to the touch switch, a state where the finger or the coordinate indicator is separated from the touch switch, and one conductor is 1 Capacitive coupling provided with means for discriminating between a state placed on only one touch switch and a state where one conductor is placed across a plurality of touch switches, and means for notifying the state by the discriminating means Electrostatic sensor. 2. The capacitive coupling type electrostatic sensor according to claim 1, wherein for one touch switch, the switch electrode group B is connected to the switch electrode group A via the wiring for driving the switch electrode of the switch electrode group A and the current / voltage conversion circuit. It has a plurality of wiring patterns of wirings connected to the switch electrodes, the voltage converted into the DC signal is measured by the plurality of wiring patterns for each of the plurality of touch switches, and a finger or a coordinate indicator A state in which the touch switch is close, a state in which a finger or a coordinate indicator is separated from the touch switch, a state in which one conductor is placed over a plurality of touch switches, and one touch switch in one conductor A capacitive coupling type electrostatic sensor provided with a means for discriminating the state of being placed only on the surface. 2. The capacitive coupling type electrostatic sensor according to claim 1 , wherein a switch for driving the switch electrode of the switch electrode group A for each of the plurality of touch switches and the switch of the switch electrode group B via the current / voltage conversion circuit. Wiring pattern of wiring connected to the electrode, wiring for driving the switch electrode of the switch electrode group A between adjacent touch switches, and wiring connected to the switch electrode of the switch electrode group B via the current / voltage conversion circuit The voltage converted into the DC signal is measured by a wiring pattern for each of a plurality of touch switches and between adjacent touch switches, and a finger or a coordinate indicator is a touch switch based on a result of calculation processing. Close to the touch panel, a finger or coordinate indicator is separated from the touch switch, and one conductor is connected to multiple touch switches. And a state of mounting across pitch, capacitive coupling type electrostatic sensor having means for discriminating between a state in which one conductor is placed on only one of the touch switches. 2. The capacitive coupling type electrostatic sensor according to claim 1 , wherein the placement information of the conductor is held, and when the finger or the coordinate indicator comes close to the touch switch while the conductor is placed, one conductor is Placed across multiple touch switches, with finger or coordinate indicator in proximity to touch switch, one conductor placed in only one touch switch, finger or coordinate indicator in proximity to touch switch An electrostatic capacity coupling type electrostatic sensor provided with means for determining a state. A plurality of switch electrodes made of a conductive material are arranged on an insulator, and a capacitance of a touch switch in which a capacitor is formed between the switch electrodes belonging to the switch electrode group A and the switch electrodes belonging to the switch electrode group B is measured . Therefore, a signal generated by an oscillator is converted into a sin signal and a cos signal synchronized by a synchronous oscillation circuit, and a switch electrode belonging to the switch electrode group A to which the sin signal is applied is selected and driven, A current / voltage conversion circuit, a wiring for selecting and connecting the switch electrodes belonging to the switch electrode group B via the current / voltage conversion circuit, a multiplication circuit for multiplying the current / voltage converted signal by the sin signal and the cos signal, a low-pass filter circuit for a signal from the multiplying circuit and a DC signal, thereby measuring the DC signal of voltage, to processing In a capacitive coupling type electrostatic sensor composed of a control device, a state where a finger or a coordinate indicator is close to the touch switch, a state where the finger or the coordinate indicator is separated from the touch switch, and one conductor is 1 Means for discriminating the state placed on only one touch switch, and means for notifying the state by the discriminating means, and a state where a finger or a coordinate indicator is close to only the touch switch and one conductor The capacitive coupling type electrostatic sensor is a means for discriminating the state of being placed only on one touch switch as a phase difference between the sin signal and the cos signal measured as the voltage converted into the DC signal . A plurality of switch electrodes made of a conductive material are arranged on an insulator, and a capacitance of a touch switch in which a capacitor is formed between the switch electrodes belonging to the switch electrode group A and the switch electrodes belonging to the switch electrode group B is measured . Therefore, a signal generated by an oscillator is converted into a sin signal and a cos signal synchronized by a synchronous oscillation circuit, and a switch electrode belonging to the switch electrode group A to which the sin signal is applied is selected and driven, A current / voltage conversion circuit, a wiring for selecting and connecting the switch electrodes belonging to the switch electrode group B via the current / voltage conversion circuit, a multiplication circuit for multiplying the current / voltage converted signal by the sin signal and the cos signal, a low-pass filter circuit for a signal from the multiplying circuit and a DC signal, thereby measuring the DC signal of voltage, to processing In a capacitive coupling type electrostatic sensor composed of a control device, a state where a finger or a coordinate indicator is close to the touch switch, a state where the finger or the coordinate indicator is separated from the touch switch, and one conductor is 1 Means for discriminating the state placed on only one touch switch, means for notifying the state by the discriminating means, and means for measuring noise having the same frequency as the sin signal and cos signal synchronized by the synchronous oscillation circuit capacitive coupling type electrostatic sensor with and.

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