JP5158493B2 - Touch switch detection device and water supply device using the same - Google Patents

Description

  An aspect of the present invention generally relates to a touch switch detection device and a water supply device using the touch switch detection device, and more specifically, to a capacitive touch switch detection device and a water supply device using the same.

  There is one that detects an operation start and an operation end by an increase and a decrease in detection output of an electrostatic touch switch detection device (for example, Patent Document 1). The touch switch detection device described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-150733) uses the differential signal of the detection signal, accurately detects the start and end of the touch state of the touch sensor, and continues the contact state. Judge the time.

However, even if it is attempted to detect the start and end of the contact state with the differential signal of the increase and decrease of the detection output of the electrostatic touch switch detection device, the increase in the detection output and Since the case where the drop has a predetermined inclination is not considered, whether the touch switch detection device described in Patent Document 1 (Japanese Patent Laid-Open No. 2007-150733) is a human operation or whether water droplets have adhered to it. There is a problem that it cannot be determined.
JP 2007-150733 A

  The aspect of the present invention has been made on the basis of recognition of such a problem, and by appropriately performing the object determination and the separation determination, whether the touch switch operation is performed by a human operation or by the attachment of water droplets, etc. Provided are a touch switch detection device and a water supply device using the touch switch detection device that can accurately determine whether or not the object is an object.

  According to an aspect of the present invention, a touch detection electrode that detects a change in capacitance due to a user's contact or separation, a detection unit that outputs a detection output reflecting the change in capacitance, and the detection output An operation determination unit that determines the presence or absence of a user's operation based on whether the change rate of the detection output at the start of detection is equal to or less than a predetermined object determination value An object determination unit that determines an object that touches the touch detection electrode; and a separation determination unit that determines whether the user is separated based on whether a change rate of the detection output is equal to or greater than a predetermined separation value. The operation determination unit sets an operation determination value according to the object determined by the object determination unit, and determines whether the change rate of the detection output is equal to or higher than the operation determination value. Touch characterized by determining presence or absence of operation Switch detection apparatus is provided.

  According to another aspect of the present invention, the touch switch detection device, an electromagnetic valve that opens and closes a water supply channel, a water outlet that discharges water supplied through the water supply channel, A water supply apparatus comprising: a control unit that controls the operation of the electromagnetic valve based on the determination of the operation determination unit.

  According to the aspect of the present invention, it is possible to accurately determine whether the operation of the touch switch is performed by a human operation or the attachment of water droplets by accurately performing the object determination and the separation determination. A switch detection device and a water supply device using the same are provided.

A first invention is based on a touch detection electrode that detects a change in capacitance due to contact or separation of a user, a detection unit that outputs a detection output reflecting the change in capacitance, and the detection output. An operation determination unit that determines whether or not the user has operated, wherein the operation determination unit determines whether the change rate of the detection output at the start of detection is equal to or less than a predetermined object determination value. An object determination unit that determines an object that touches the object, and a separation determination unit that determines whether the user is separated based on whether a change rate of the detection output is equal to or greater than a predetermined separation value, and the operation The determination unit sets an operation determination value according to the object determined by the object determination unit, and whether or not there is an operation by the user depending on whether the change rate of the detection output is equal to or higher than the operation determination value. Touch switch detection, characterized by It is a device.
As a result, whether the operation of the touch switch detection device is due to human operation or due to the attachment of water droplets, the initial change in the detection output due to the difference in the capacitance of the object to be detected Since the rates are different, it is possible to accurately determine the target object by estimating the target object based on the rate of change and setting a detection condition more suitable for the target object.

According to a second aspect of the present invention, in the first aspect, when the rate of change of the detection output is equal to or greater than the operation determination value, the operation determination unit determines that the user has operated. There is a touch switch detection device.
As a result, with regard to the inherent capacitance, a human finger is larger than a water drop, so the rate of change in detection output detected by the finger is greater than that of a water drop, and the touch switch detection device is operated by a human. It is possible to more accurately determine whether or not the operation is due to the above operation.

In a third aspect based on the first aspect, the operation determination value includes a first operation determination value and a second operation determination value that is larger than the first operation determination value. The touch switch detection device is characterized by being set to either one.
As a result, two large and small operation determination values are set and a certain range is provided for the determination reference, so that it is possible to more accurately determine whether or not the operation of the touch switch detection device is due to adhesion of water droplets or the like.

In a fourth aspect based on the third aspect, the operation determination is performed when a change rate of the detection output is not between the first operation determination value and the second operation determination value. The unit is a touch switch detection device that determines that the user has operated.
As a result, it is possible to accurately determine when the user releases the touch switch quickly or slowly, and when the operation of the touch switch detection device is due to the attachment of water droplets, etc. Can not be accepted.

According to a fifth aspect of the present invention, in the first to fourth aspects of the invention, when the operation determination unit determines that the object is a water droplet, the operation determination unit contacts the object with the user. The touch switch detection device is characterized in that the operation determination value is set to a value larger than that determined when the operation determination value is determined.
As a result, when the user removes the wet finger from the touch detection electrode, the touch detection electrode and the user's finger continue to contact each other due to the surface tension of the water droplet, and the contact suddenly disappears at the critical point where the surface tension breaks Thus, the phenomenon that the rate of change (decrease rate) in the voltage value increases can be determined more accurately.

Moreover, 6th invention is the electromagnetic valve which opens and closes a water supply flow path, the water discharge port which discharges the water supplied through the said water supply flow path, and said operation. A water supply device comprising: a control unit that controls the operation of the electromagnetic valve based on the determination of the determination unit.
As a result, it is possible to perform a water discharge operation by making a more accurate operation determination without malfunction even when a water droplet is applied.

The seventh invention is characterized in that, in the sixth invention, at least one of the predetermined object judgment value and the operation judgment value is changed according to an open / close state of the electromagnetic valve. It is a water supply device.
As a result, the case where the user presses the touch detection electrode with a dry finger, the case where the user presses the touch detection electrode with a wet finger, and the case where a water droplet is attached to the touch detection electrode can be determined more accurately.

In addition, in an eighth aspect based on the seventh aspect, the operation determination unit is configured such that when the electromagnetic valve is in an open state, the predetermined object determination value that is larger than that in the case where the electromagnetic valve is in a closed state, and The water supply device is characterized in that the operation determination value is set.
As a result, when the solenoid valve is in the open state, the touch detection electrode is likely to be splashed with water, and it is often operated with wet hands when stopping the water, so the influence of water droplets on the operation of the touch detection electrode This makes it possible to make a more accurate operation determination.

Embodiments of the present invention will be described below with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.
FIG. 1 is a block diagram of a touch switch detection device according to an embodiment of the present invention.
A touch switch detection device 100 according to an embodiment of the present invention includes a touch detection electrode 200, a detection unit 300, and an operation determination unit 400. As will be described later, the touch detection electrode 200 is provided, for example, directly below a panel of a water supply device or the like. Note that touching the panel by the user is equivalent to touching the touch detection electrode 200. The detection unit 300 includes an oscillation unit 310 and a voltage conversion unit 320. Further, the operation determination unit 400 includes a separation determination unit 420 and an object determination unit 430.

  The oscillation unit 310 outputs a high frequency signal, forms a high frequency voltage based on the high frequency signal, and applies the high frequency voltage to the touch detection electrode 200. When the user does not touch the touch detection electrode 200 with a finger, the voltage amplitude (oscillation intensity) of the high frequency voltage applied to the touch detection electrode 200 does not change and is output to the voltage conversion unit 320. On the other hand, when the user touches the touch detection electrode 200 with a finger, the capacitance between the touch detection electrode 200 and the ground changes. As a result, the voltage amplitude (oscillation intensity) of the high-frequency voltage applied to the touch detection electrode 200 changes according to the change in capacitance, and is output to the voltage conversion unit 320. The voltage conversion unit 320 outputs the output of the oscillation unit 310 to the operation determination unit as a voltage value detection signal.

  The object determination unit 430 determines an object that has touched the touch detection electrode 200 according to the output change rate at the start of detection of the detection signal (detection output) output from the voltage conversion unit 320. On the other hand, when the separation determination unit 420 receives the detection signal output from the voltage conversion unit 320, the separation determination unit 420 determines whether a human finger or the like has separated from the touch detection electrode 200 based on an operation described in detail later. .

FIG. 2 is a block diagram of a water supply device using the touch switch detection device according to the present embodiment.
Moreover, FIG. 3 represents the schematic diagram of the water supply apparatus using the touch switch detection apparatus concerning this embodiment.
The touch switch detection device 100 according to the present embodiment is used in, for example, a water supply device. A water supply device 500 shown in FIGS. 2 and 3 includes a touch switch detection device 100, a control unit 510, an electromagnetic valve 520, and a water discharge port 530.

  The water supply device illustrated in FIG. 3 includes touch switch detection devices 100a, 100b, and 100c. For example, the touch switch detection device 100a is a “water discharge switch”, the touch switch detection device 100b is a “flow rate adjustment switch”, and a touch switch. The detection device 100c can have a function as a “water stop switch”.

  Based on the signal output from touch switch detection device 100, control unit 510 determines the presence or absence of a user's operation, and instructs electromagnetic valve 520 to perform a spouting operation. The electromagnetic valve 520 opens and closes the valve based on the instruction output from the control unit 510. Thereby, the water discharge from the water outlet 530 of the water supply apparatus 500 is controlled.

FIG. 4 is a graph showing a voltage value (actual measurement value) output from the detection unit when the touch detection electrode is pressed with a dry finger.
The vertical axis of the graph shown in FIG. 4 represents a voltage value (100 mV / div), and the horizontal axis represents time (50 ms / div).

  When the user touches the touch detection electrode 200 with a dry finger, as described above with reference to FIG. 1, the capacitance between the touch detection electrode 200 and the ground changes, and the voltage value output from the detection unit 300 increases. The detection signal changes. In addition, when the touch detection electrode 200 is touched with a dry finger, the contact area of the finger with the touch detection electrode 200 gradually increases with the deformation of the fingertip, so that the graph shown in FIG. The voltage value (detection output) output from the detection unit 300 gradually increases. Here, the conversion method of the voltage conversion unit 320 may be such that the voltage value decreases when the user touches the touch detection electrode 200 with a finger.

  When the user touches the touch detection electrode 200 with his / her finger, the capacitance between the touch detection electrode 200 and the ground remains changed (increased) as compared with the case where the user does not touch the touch detection electrode 200. As shown in the graph of FIG. 4, the voltage value output from the detection unit 300 remains substantially constant while being increased. The time t1 from when the voltage value starts to rise until it becomes substantially constant is, for example, about 20 milliseconds.

  Thereafter, even when the user removes the dry finger from the touch detection electrode 200, the contact area of the finger with respect to the touch detection electrode 200 gradually decreases as the fingertip is deformed. The value gradually decreases. When the dry finger is completely separated from the touch detection electrode 200, the voltage value output from the detection unit 300 decreases to the voltage value before touching with the dry finger as shown in the graph of FIG. It becomes. The time t2 from when the voltage value starts to decrease until it becomes substantially constant is, for example, about 20 milliseconds.

FIG. 5 is a graph illustrating a voltage value (actual measurement value) output from the detection unit when a water droplet is attached to the touch detection electrode.
The vertical axis and the horizontal axis of the graph shown in FIG. 5 represent the voltage value (100 mV / div) and time (50 ms / div), respectively, as in the graph shown in FIG.

  When a water droplet is attached to the touch detection electrode 200, the capacitance between the touch detection electrode 200 and the water droplet changes, and the detection signal of the voltage value output from the detection unit 300 changes, as in the case of touching with a finger. To do. When a water droplet is attached to the touch detection electrode 200, the contact area of the water droplet with respect to the touch detection electrode 200 is rapidly increased compared to the case where the touch detection electrode 200 is touched with a dry finger. The change rate (increase rate) of the voltage value output from 300 is greater than the increase rate when touched with a dry finger. The time from the start of the increase of the voltage value to the end of the increase is, for example, about 5 milliseconds. Here, the conversion method of the voltage conversion unit 320 may be such that the voltage value decreases when a water droplet is applied to the touch detection electrode 200.

  Further, when the user is touching the touch detection electrode 200, the person is also in contact with the ground, so that the charge transmitted from the touch detection electrode 200 to the user escapes to the ground through the human body. Therefore, the voltage value output from the detection unit 300 until the user lifts the finger is maintained at a certain voltage value. On the other hand, when a water droplet is attached, the charge is transferred from the touch detection electrode 200 to the water droplet, so that charging proceeds to the capacitive component of the water droplet, and finally the touch detection electrode 200 and the water droplet are at the same potential. turn into. Therefore, even when the water droplet remains on the touch detection electrode 200, the voltage value gradually decreases as shown in FIG. The speed at which the charge is transferred from the touch detection electrode 200 to the water droplet is determined by the capacitance component of the water droplet, but is slower than the speed at which the user lifts the finger from the touch detection electrode 200. For this reason, the voltage value decrease rate in a state where the water droplet remains on the touch detection electrode 200 is smaller than the voltage value decrease rate when the user lifts the dry finger from the touch detection electrode 200 and gradually decreases. I will do it. The time t4 from when the voltage value starts to decrease until it becomes substantially constant is slightly different depending on the amount of water droplets, but is about 150 milliseconds in the actual measurement value shown in FIG.

FIG. 6 is a graph showing a voltage value (actual measurement value) output from the detection unit when the touch detection electrode of this embodiment is pressed with a wet finger.
The vertical axis and the horizontal axis of the graph shown in FIG. 6 represent the voltage value (100 mV / div) and time (50 ms / div), respectively, similarly to the graph shown in FIG. 6 is a waveform of a voltage value when a user presses the touch detection electrode while the water drop on the finger does not fall on the touch detection electrode 200 and remains on the finger. Represents.

  When the user touches the touch detection electrode 200 with a wet finger, the water attached to the finger spreads quickly to the touch detection electrode 200, so that the voltage value increases at a higher rate than when touched with a dry finger. . The time t5 from when the voltage value starts to rise until it becomes substantially constant is, for example, about 10 milliseconds. Furthermore, since the finger is wet with water, the contact area with respect to the touch detection electrode 200 is increased by the amount wet. Therefore, the capacitance is larger than that when touching with a dry finger, and as a result, the voltage value while the user touches the touch detection electrode 200 with a wet finger is dry as shown in FIG. It is larger than the voltage value while touching with a finger (see FIG. 4).

  After that, when the user releases the wet finger from the touch detection electrode 200, the touch detection electrode 200 and the finger come into contact with each other through the water due to the surface tension of water even if the finger tries to move away from the touch detection electrode 200. The state continues. When the finger is separated to some extent, the water is separated from the finger, and as a result, the finger is separated from the touch detection electrode 200 at a stretch. Therefore, the contact area between the finger and the touch detection electrode 200 does not gradually decrease as in the case where the touch detection electrode 200 is pressed with a dry finger. Therefore, when the wet finger moves away from the touch detection electrode 200, the voltage value decreases at a larger change rate than that of the dry finger.

  As described above, even when the user presses the touch detection electrode 200 with a finger, the rate of increase in the voltage value output from the detection unit 300 differs depending on the wetness of the finger. Therefore, even if the voltage value changes at a higher rate than when the touch detection electrode 200 is pressed with a dry finger, it cannot be determined that there is no user operation. That is, it is not possible to determine whether or not the user has performed an operation only by determining the object that has touched the touch detection electrode 200 based on the rate of change (increase rate) when the voltage value increases.

Next, a specific example of the determination operation of the touch switch detection device according to the present embodiment will be described with reference to the drawings.
FIG. 7 is a schematic view illustrating the case where the touch detection electrode is pressed with a dry finger. 7A is a schematic diagram illustrating a state in which the touch detection electrode is touched with a dry finger, and FIG. 7B is a schematic diagram illustrating a voltage value output from the detection unit.

  When the user presses the touch detection electrode 200 with a dry finger, the voltage value output from the detection unit 300 gradually increases (range A1), and the voltage value remains increased and becomes substantially constant (range B1). Here, the operation determination unit 400 calculates the rate of change (increase rate) of the voltage value output from the detection unit 300, as will be described in detail later. An object touching the touch detection electrode 200 is determined according to the change rate (here, about 20 milliseconds), and an operation determination value that is a threshold value for the change rate (decrease rate) of the voltage value is set.

  Thereafter, when the user removes his / her finger from the touch detection electrode 200, the voltage value output from the detection unit 300 gradually decreases (range C1). For example, the voltage before pressing the touch switch detection device in about 20 milliseconds. The value is substantially constant (range D1).

  Here, as illustrated in FIG. 7B, when the absolute value of the decrease rate of the voltage value is larger than the absolute value of the operation determination value, the operation determination unit 400 is assumed to have been operated by the user. The touch switch detection apparatus 100 accepts this operation. That is, the touch switch detection device 100 according to the present embodiment does not determine the presence / absence of the user's operation only by determining the object that has touched the touch detection electrode 200, but does not determine the operation determination value ( By comparing the absolute value of (threshold value) with the absolute value of the rate of decrease in voltage value, the presence / absence of a user operation is determined. In the present specification, the user's operation is not only an operation in which the user touches the touch detection electrode 200 with a finger or the like, but also an operation in which a touching operation (contact operation) and a releasing operation (separation operation) are combined. Say.

  On the other hand, when the absolute value of the decrease rate of the voltage value is smaller than the absolute value of the operation determination value, as will be described later, the operation determination unit 400 determines that there is no user operation, and the touch switch The detection apparatus 100 does not accept this operation.

  In the specific example shown in FIG. 7, the change rate of the voltage value when the user lifts his / her finger from the touch detection electrode 200 is negative (minus). Compare the magnitude relationship of the absolute values of and. On the other hand, depending on the configuration of the detection circuit of the detection unit 300, the change rate of the voltage value when the finger is removed from the touch detection electrode 200 may be positive (plus). If the change rate of the voltage value when the user releases the finger from the touch detection electrode 200 is positive, the magnitude relationship between the change rate of the voltage value and the operation determination value is compared without considering the absolute value. May be. As described above, since the rate of change of the voltage value output from the detection unit 300 may be positive or negative, the operation of a specific example will be described below in consideration of the absolute value. In addition, a large change rate of the voltage value output from the detection unit 300 means that the gradient of the change is steep. On the other hand, a small change rate of the voltage value output from the detection unit 300 means that the slope of the change is gentle.

  FIG. 8 is a schematic view illustrating the case where water droplets are attached to the touch detection electrode. FIG. 8A is a schematic diagram illustrating a state in which water droplets are attached to the touch detection electrode, and FIG. 8B is a schematic diagram illustrating a voltage value output from the detection unit.

  When the water droplet is attached to the touch detection electrode 200, as described above with reference to FIG. 5, the voltage value output from the detection unit 300 increases at a large increase rate (range A2). The operation determination unit 400 calculates the rate of change (the rate of increase), determines the object that has touched the touch detection electrode 200 according to the rate of change (here, about 5 milliseconds), and the rate of change of the voltage value. An operation determination value that is a threshold value (decrease rate) is set.

  Subsequently, as described above with reference to FIG. 5, it is assumed that the time until the voltage value starts to decrease and becomes substantially constant as a result of the voltage value gradually decreasing is about 40 milliseconds, for example. In the change of the voltage value shown in FIG. 8B, the decrease rate in the range B2 is different from the decrease rate in the range C2, but it is not limited to this and is the same. Also good.

  At this time, as described above with reference to FIG. 5, the absolute value of the decrease rate of the voltage value when the water droplet is attached to the touch detection electrode 200 is the voltage value when the user presses the touch detection electrode 200 with a dry finger. Is smaller than the absolute value of the decrease rate. Therefore, depending on the setting of the operation determination value, the absolute value of the decrease rate of the voltage value when a water droplet is attached to the touch detection electrode 200 is smaller than the absolute value of the operation determination value, and the user moves the touch detection electrode 200. The absolute value of the decrease rate of the voltage value when pressed with a dry finger may be larger than the absolute value of the operation determination value. When the absolute value of the voltage value decrease rate is smaller than the absolute value of the operation determination value, the operation determination unit 400 determines that there is no user operation, and the touch switch detection device 100 does not accept this operation.

  Therefore, the operation determination unit 400 sets an operation determination value according to the object that has touched the touch detection electrode 200, and determines the magnitude relationship between the absolute value of the operation determination value and the absolute value of the voltage value decrease rate. By comparing, the presence or absence of the user's operation can be determined more accurately.

FIG. 9 is a schematic view illustrating the case where the touch detection electrode is pressed with a wet finger. FIG. 9A is a schematic view illustrating a state in which water droplets attached to the finger have fallen on the touch detection electrode, and FIG. 9B illustrates a state immediately after the finger is released from the touch detection electrode. FIG. 9C is a schematic diagram illustrating a state where the finger is completely separated from the touch detection electrode.
FIG. 10 is a schematic diagram illustrating voltage values when the touch detection electrode is pressed with a wet finger.

  When the user tries to push the touch detection electrode 200 with a wet finger, if a water droplet attached to the finger falls on the touch detection electrode 200, the voltage value output from the detection unit 300 increases at a large increase rate. (Range A3). This is because it can be considered in the same manner as when a water droplet is attached to the touch detection electrode 200 (see FIG. 8). The operation determination unit 400 calculates the rate of change (the rate of increase), determines the object that has touched the touch detection electrode 200 according to the rate of change (here, about 5 milliseconds), and the rate of change of the voltage value. An operation determination value that is a threshold value (decrease rate) is set. That is, the operation determination value shown in FIG. 8B and the operation determination value shown in FIG. 10 are substantially the same.

  Subsequently, while the user presses the touch detection electrode 200 with his / her finger, the voltage value remains increased and becomes substantially constant (range B3). Further, even if the finger is separated from the touch detection electrode 200, as shown in FIG. 9B, the finger and the touch detection electrode 200 are in contact with each other through the water drop to a certain height due to the surface tension of the water drop. Therefore, the voltage value remains substantially constant while being increased (range B3).

  Thereafter, when the water droplet is separated from the finger, the finger is separated from the touch detection electrode 200 at a stretch as shown in FIG. Therefore, the contact area between the finger and the touch detection electrode 200 does not gradually decrease as in the case where the touch detection electrode 200 is pressed with a dry finger. Therefore, the voltage value decreases at a larger decrease rate than when the touch detection electrode 200 is pressed with a dry finger (range C3).

  At this time, as shown in FIG. 10, the absolute value of the decrease rate of the voltage value when the wet finger is removed from the touch detection electrode 200 is the decrease rate of the voltage value when a water droplet is attached to the touch detection electrode 200. Is greater than the absolute value of. Therefore, depending on the setting of the operation determination value, the absolute value of the decrease rate of the voltage value when a water droplet is attached to the touch detection electrode 200 is smaller than the absolute value of the operation determination value, and the user moves the touch detection electrode 200. The absolute value of the decrease rate of the voltage value when pressed with a wet finger may be larger than the absolute value of the operation determination value. Therefore, it is possible to more accurately determine the case where the user presses the touch detection electrode 200 with a wet finger and the case where a water droplet is attached to the touch detection electrode 200.

  FIG. 11 is a schematic view illustrating the case where the touch detection electrode is pressed with a wet finger. FIG. 11A is a schematic view illustrating a state in which water droplets attached to the finger do not fall on the touch detection electrode, and FIG. 11B shows a state immediately after the finger is released from the touch detection electrode. FIG. 11C is a schematic diagram illustrating a state where the finger is completely separated from the touch detection electrode. FIG. 12 is a schematic diagram illustrating voltage values when the touch detection electrode is pressed with a wet finger.

  When the touch detection electrode 200 is pressed while the water droplet is still on the finger, the water attached to the finger spreads quickly with respect to the touch detection electrode 200, and therefore the voltage value is increased at a higher rate than when touched with a dry finger. Rises (range A4). The operation determination unit 400 calculates the rate of change (increase rate), determines an object that has touched the touch detection electrode 200 according to the rate of change (here, about 10 milliseconds), and the rate of change in voltage value. An operation determination value that is a threshold value (decrease rate) is set.

  Subsequently, immediately after the finger is released from the touch detection electrode 200, as described above with reference to FIG. 9B, the finger and the touch detection electrode 200 are in contact with each other through the water droplets up to a certain height. As in the case where the touch detection electrode 200 is being pressed with a finger, the voltage value remains increased and becomes substantially constant (range B4).

  Thereafter, when the user completely removes the finger from the touch detection electrode 200, as described above with reference to FIG. 9C, the voltage value decreases at a higher rate than when the touch detection electrode 200 is pressed with a dry finger. (Range C4).

  Therefore, as in the case described above with reference to FIGS. 9 and 10, depending on the setting of the operation determination value, the absolute value of the decrease rate of the voltage value when the water droplets are attached to the touch detection electrode 200 is the absolute value of the operation determination value. The absolute value of the voltage value reduction rate when the user presses the touch detection electrode 200 with a wet finger may be larger than the absolute value of the operation determination value. Therefore, it is possible to more accurately determine the case where the user presses the touch detection electrode 200 with a wet finger and the case where a water droplet is attached to the touch detection electrode 200.

  FIG. 13 is a schematic view illustrating the case where the touch detection electrode with a water droplet is pressed with a dry finger. 13A is a schematic diagram illustrating a state in which the touch detection electrode 200 with water droplets is pressed with a dry finger, and FIG. 13B is a schematic diagram illustrating a voltage value output from the detection unit. It is.

  When the user presses the touch detection electrode 200 with water droplets with a dry finger, the apparent contact area with the touch detection electrode 200 immediately expands, so that the touch detection electrode 200 without water droplets is pressed with a finger. The voltage value increases at a large increase rate (range A5). The rate of increase of the voltage value at this time is when the water droplets are attached to the touch detection electrode 200 (see FIG. 8) and when the water droplets are dropped from a finger wet on the touch detection electrode 200 (see FIGS. 9 and 10). It becomes almost the same as the rate of increase. The operation determination unit 400 calculates the rate of change (the rate of increase), determines the object that has touched the touch detection electrode 200 according to the rate of change (here, about 5 milliseconds), and the rate of change of the voltage value. An operation determination value that is a threshold value (decrease rate) is set. That is, the operation determination value shown in FIG. 13B is set to substantially the same rate of change as the operation determination value shown in FIGS. 8B and 10.

  Subsequently, the decrease rate of the voltage value when the finger is released from the touch detection electrode 200 is larger than that in the state where water droplets remain attached, as in the case illustrated in FIGS. 9B and 9C. The voltage value decreases at a rate (range C5).

  Therefore, depending on the setting of the operation determination value, the absolute value of the decrease rate of the voltage value when a water droplet is attached to the touch detection electrode 200 is smaller than the absolute value of the operation determination value and the touch detection electrode 200 with a water droplet is attached. In some cases, the absolute value of the decrease rate of the voltage value when pressing with a dry finger is greater than the absolute value of the operation determination value. Therefore, it is possible to more accurately determine when the touch detection electrode 200 with water droplets is pressed with a dry finger and when the touch detection electrode 200 has water droplets.

FIG. 14 is a flowchart illustrating a specific example of the operation of the operation determination unit of this embodiment.
The operation determination unit 400 first determines an object that has touched the touch detection electrode 200 by using the object determination unit 430 (step S102). The operation of the object determination unit 430 will be described later with reference to FIG.

When the object determination unit 430 determines that the object in contact with the touch detection electrode 200 is “object 1” (step S104: YES), the operation determination unit 400 determines the rate of change in voltage value (decrease rate). ) Is set to “α1” (step S110). Similarly, in the case of “target 2” (step S106: YES), the operation determination unit 400 sets “α2” as the operation determination value (step S112), and “target (N−1)”. ”(Step S108: YES),“ α _n−1 ”is set as the operation determination value (step S114). In other cases (step S108: NO),“ α _n ”is set as the operation determination value. Set (step S116).

  Subsequently, the separation determination unit 420 determines whether or not a finger or the like has separated from the touch detection electrode 200 (step S118). The operation of the separation determination unit 420 will be described later with reference to FIG. When it is determined that a finger or the like is separated from the touch detection electrode 200, the operation determination unit 400 determines that the absolute value of the change rate (decrease rate) of the voltage value output from the detection unit 300 is step S110, step S112, step It is determined whether or not the operation determination value set in S114 or step S116 is larger than the absolute value (step S120).

  When the absolute value of the change rate of the voltage value output from the detection unit 300 is larger than the absolute value of the set operation determination value (step S120: YES), the operation determination unit 400 has an operation by the user. (Step S122). On the other hand, when the absolute value of the change rate of the voltage value output from the detection unit 300 is smaller than the absolute value of the set operation determination value (step S120: NO), the operation determination unit 400 performs the user's operation. It is determined that there was no (step S124). Therefore, the operation determination unit 400 can more accurately determine the presence / absence of the user's operation by determining the contact operation and the separation operation of the object that contacts the touch detection electrode 200.

FIG. 15 is a flowchart illustrating a specific example of the operation of the object determination unit of the present embodiment.
The object determination unit 430 first reads the detection output (voltage value) output from the detection unit 300 (step S202). Subsequently, the change rate (increase rate) of the voltage value is calculated based on the read voltage value (step S204). If the rate of change is “0” (step S206: NO), the detection output (voltage value) output from the detection unit 300 is read again (step S202). On the other hand, if the rate of change is not “0” (step S206: YES), the object determining unit 430 determines whether the absolute value of the rate of change calculated in step S204 is equal to or smaller than the absolute value of the predetermined object determined value A1. It is determined whether or not (step S208).

  If the absolute value of the change rate calculated in step S204 is less than or equal to the absolute value of the predetermined object determination value A1, the object determination unit 430 determines that the object that has touched the touch detection electrode 200 is “object 1”. Judgment is made (step S214). On the other hand, if the absolute value of the change rate calculated in step S204 is not less than or equal to the absolute value of the predetermined object determination value A1 (step S208: NO), the object determination unit 430 calculates the absolute value of the change rate calculated in step S204. It is determined whether or not the value is equal to or less than an absolute value of a predetermined object determination value A2 (step S210).

If the absolute value of the change rate calculated in step S204 is less than or equal to the absolute value of the predetermined object determination value A2, the object determination unit 430 determines that the object that has touched the touch detection electrode 200 is “object 2”. Judgment is made (step S216). On the other hand, if the absolute value of the change rate calculated in step S204 is not less than or equal to the absolute value of the predetermined object determination value A2 (step S210: NO), the object determination unit 430 calculates the absolute value of the change rate calculated in step S204. It is determined whether or not the value is equal to or less than an absolute value of a predetermined object determination value _An-1 (step S212).

If the absolute value of the change rate calculated in step S204 is equal to or less than the absolute value of the predetermined object determination value _An-1 , the object determination unit 430 determines the object that has touched the touch detection electrode 200 as “object (N -1) "(step S218). On the other hand, if the absolute value of the change rate calculated in step S204 is not less than or equal to the absolute value of the predetermined object determination value _An-1 (step S212: NO), the object determination unit 430 contacts the touch detection electrode 200. The determined object is determined to be “object N” (step S220).

By performing such an operation, the object determination unit 430 determines an object that has touched the touch detection electrode 200. Then, as described above with reference to FIG. 14, the operation determination unit 400 sets an operation determination value that is a threshold value of the change rate (decrease rate) of the voltage value according to the object determined by the object determination unit 430. Note that the relationship of the following expressions holds for the object determination value and the operation determination value.

| A1 | <| A2 | <... <| A _n-1 | <| A _n | Formula (1)

| Α1 | <| α2 | <... <| α _n−1 | <| α _n | Equation (2)

FIG. 16 is a flowchart illustrating a specific example of the operation of the separation determination unit of the present embodiment.
The separation determination unit 420 first reads the detection output (voltage value) output from the detection unit 300 (step S302). Subsequently, the change rate (decrease rate) of the voltage value is calculated based on the read voltage value (step S304). Subsequently, it is determined whether or not the absolute value of the change rate calculated in step S304 is larger than the absolute value of the predetermined separation value (step S306). When the absolute value of the change rate is smaller than the absolute value of the predetermined separation value (step S306: NO), the detection output (voltage value) output from the detection unit 300 is read again (step S302). On the other hand, when the absolute value of the change rate is larger than the absolute value of the predetermined separation value (step S306: YES), the separation determination unit 420 determines that a finger or the like has separated from the touch detection electrode 200, and performs the operation. The process ends (step S308).

  By performing such an operation, the separation determination unit 420 determines whether a finger or the like has separated from the touch detection electrode 200. Then, as described above with reference to FIG. 14, the absolute value of the change rate of the voltage value output from the detection unit 300 rather than the absolute value of the operation determination value set according to the object determined by the object determination unit 430. If is greater, the operation determination unit 400 determines that there has been a user operation.

Next, the operation of the operation determination unit of this example will be further described with reference to time charts corresponding to the operations of the flowcharts shown in FIGS.
FIG. 17 is a time chart for explaining a specific example of the operation of the operation determination unit of this specific example. FIG. 17A is a schematic diagram illustrating a voltage value when the touch detection electrode is pressed with a dry finger, and FIG. 17B is a voltage value when a water droplet is attached to the touch detection electrode. FIG. 17C is a schematic diagram illustrating the voltage value when the touch detection electrode is pressed with a wet finger.

  When an object comes into contact with the touch detection electrode 200 and the absolute value of the change rate (increase rate) of the voltage value is equal to or smaller than the absolute value of the predetermined object determination value A1, as shown in FIG. The object determination unit 430 determines that the object is a user's finger. As described above with reference to FIG. 4 and FIG. 7, when the touch detection electrode 200 is touched with a finger, the contact area of the finger with the touch detection electrode 200 gradually increases. This is because the applied voltage value rises more slowly than in the case of water drops.

  Here, the operation determination unit 400 sets the operation determination value to α1 based on the object (user's finger) determined by the object determination unit 430. Subsequently, since the absolute value of the voltage value change rate (decrease rate) is larger than the absolute value of the predetermined separation value, the separation determination unit 420 determines that a finger or the like has separated from the touch detection electrode 200. Here, since the absolute value of the change rate of the voltage value shown in FIG. 17A is larger than the absolute value of the operation determination value α1, the operation determination unit 400 determines that there has been an operation by the user, The touch switch detection device 100 accepts this operation.

  On the other hand, an object contacts the touch detection electrode 200, and as shown in FIG. 17B, the absolute value of the change rate (increase rate) of the voltage value is the absolute value of the predetermined object determination value A2. If it is equal to or less than the object determination value A1, the object determination unit 430 determines that the object is a water droplet or the like. As described above with reference to FIGS. 5 and 8, when a water droplet is attached to the touch detection electrode 200, the contact area of the water droplet with respect to the touch detection electrode 200 spreads quickly, and thus the voltage value output from the detection unit 300. This is because it rises more rapidly than when touched with a finger.

  Here, the operation determination unit 400 sets the operation determination value to α2 based on the object (water droplet) determined by the object determination unit 430. Subsequently, since the absolute value of the voltage value change rate (decrease rate) is larger than the absolute value of the predetermined separation value, the separation determination unit 420 determines that a finger or the like has separated from the touch detection electrode 200. However, since the absolute value of the change rate of the voltage value shown in FIG. 17B is smaller than the absolute value of the operation determination value α2, the operation determination unit 400 determines that there is no operation by the user, and the touch switch The detection apparatus 100 does not accept this operation.

  On the other hand, an object contacts the touch detection electrode 200, and as shown in FIG. 17C, the absolute value of the change rate (increase rate) of the voltage value is a predetermined object determination value A2. When the absolute value is less than the absolute value and larger than the absolute value of the object determination value A1, the object determination unit 430 determines that the object is a water drop or the like, as in the time chart shown in FIG. to decide. Note that the time chart shown in FIG. 17C illustrates the case where a water droplet attached to the finger falls on the touch detection electrode as in the case described above with reference to FIG.

  Here, the operation determination unit 400 sets the operation determination value to α2 based on the object (water droplet) determined by the object determination unit 430. Subsequently, since the absolute value of the voltage value change rate (decrease rate) is larger than the absolute value of the predetermined separation value, the separation determination unit 420 determines that a finger or the like has separated from the touch detection electrode 200. At this time, the absolute value of the change rate of the voltage value shown in FIG. 17C is larger than the absolute value of the operation determination value α2. This is because, as described above with reference to FIG. 9, when the water droplet is separated from the finger, the finger is suddenly separated from the touch detection electrode 200, and therefore, the water drops more rapidly than the case where only the water droplet is attached to the touch detection electrode 200. . In this case, the operation determination unit 400 determines that there has been a user's operation, and the touch switch detection device 100 accepts this operation.

  As described above, the operation determination unit 400 according to the present specific example has a case where the user presses the touch detection electrode 200 with a dry finger, a case where the user presses the touch detection electrode 200 with a wet finger, and a case where a water droplet is attached to the touch detection electrode 200. Can be determined more accurately. Therefore, it is possible to accurately determine whether the operation of the touch switch detection device 100 is due to a human operation or due to water droplet adhesion.

  FIG. 18 is a flowchart illustrating another specific example of the operation of the operation determination unit according to this embodiment. Note that the operation of the operation determination unit illustrated in FIG. 18 illustrates a case where the touch switch detection device 100 is used in a device having an on-off valve such as the electromagnetic valve 520 such as the water supply device illustrated in FIG. ing.

  When the electromagnetic valve 520 is open, the water supply device using the touch switch detection device 100 is used by the user, and there is a high possibility that the user's hand is wet. Further, when the electromagnetic valve 520 is open, the device is used by the user, and there is a high possibility that water droplets will be attached to the touch detection electrode 200 due to reflection on the cleaning object. Therefore, the operation determination unit 400 of this specific example estimates that the user is likely to press the touch detection electrode 200 with a wet finger when the electromagnetic valve 520 is open, and the electromagnetic valve opens. The object judgment value and the operation judgment value can be changed depending on whether the object is closed or closed.

The operation determination unit 400 first determines whether or not the electromagnetic valve 520 is closed (step S402). If the solenoid valve is closed (step S404: YES), a predetermined object determination value is set to _{A1, A2, A n-1} , and _{A n} (step S404), the solenoid valve is opened If it is present (step S402: NO), the predetermined object judgment value is set to B1, B2, B _n-1 , and B _n (step S406). The relationship of the formula (1) is established for the object determination value A, and for the object determination value B and between the object determination value A and the object determination value B, It holds.

| B1 | <| B2 | <... <| _Bn-1 | <| _Bn | Formula (3)

| A1 | <| B1 | Formula (4)

| A2 | <| B2 | Formula (5)

| A _n-1 | <| B _n-1 | Formula (6)

| A _n | <| B _n | Formula (7)

This is because the absolute value of the increase rate and the decrease rate of the voltage value is larger when the touch detection electrode 200 is pressed with a wet finger than with a dry finger.

Subsequently, the target object determination unit 430 determines the target object that has touched the touch detection electrode 200 by performing the operation illustrated in FIG. 15 (step S408). Subsequently, the operation determination unit 400 determines again whether or not the electromagnetic valve 520 is closed (step S410). When the electromagnetic valve 520 is closed (step S410: YES), the operation determination value is set to α1, α2, or the like according to the object determined by the object determination unit 430 (step S412, step S414, step S416). α _n-1 or α _n is set (step S418, step S420, step S422, step S424). On the other hand, when the electromagnetic valve 520 is open (step S410: NO), the operation determination value is set to β1, according to the object determined by the object determination unit 430 (step S426, step S428, step S430). .beta.2, set to beta _n-1 or beta _n, (step S432, step S434, step S436, step S438). Note that the relationship of Expression (2) is established for the operation determination value α, and the following expression is established for the operation determination value β and between the operation determination value α and the operation determination value β.

| Β1 | <| β2 | <... <| β _n-1 | <| β _n | Equation (8)

| Α1 | <| β1 | Formula (9)

| Α2 | <| β2 | Formula (10)

| Α _n-1 | <| β _n-1 | Formula (11)

| Α _n | <| β _n | Equation (12)

  Subsequently, the operation determination unit 400 determines the presence / absence of the user's operation by performing the same operations as in Step S118, Step S120, Step S122, and Step S124 illustrated in FIG. When the operation determination unit 400 determines that there has been a user operation, the touch switch detection device 100 accepts this operation. On the other hand, when the operation determination unit 400 determines that there is no user operation, the touch switch detection device 100 does not accept this operation.

Next, the operation of the operation determination unit of this example will be further described with reference to a time chart corresponding to the operation of the flowchart shown in FIG.
FIG. 19 is a schematic view illustrating voltage values when the touch detection electrode is pressed with a finger to open the electromagnetic valve. FIG. 19A is a schematic diagram illustrating voltage values when the touch detection electrode is pressed with a dry finger to open the solenoid valve, and then pressed with a wet finger to close the solenoid valve. FIG. 19B is a schematic diagram illustrating voltage values when a minute amount of water droplets are attached to the touch detection electrode after the touch detection electrode is pressed with a dry finger to open the solenoid valve.

When the user presses the touch detection electrode 200 with a dry finger to open the electromagnetic valve 520, the electromagnetic valve 520 is closed, so that the operation determination unit 400 sets the predetermined object determination values to A1, A2, set to a _n-1, and _{a n.} Subsequently, the object determination unit 430 detects the object that has touched the touch detection electrode 200 based on the fact that the absolute value of the rate of change (increase rate) of the voltage value is equal to or less than the absolute value of the predetermined object determination value A1. Is determined to be a user's finger, and the operation determination value is set to “α1”. According to the time chart shown in FIG. 19A, the absolute value of the change rate (decrease rate) of the voltage value is larger than the absolute value of the operation determination value α1, so that the operation is accepted and the electromagnetic valve 520 is opened. To do.

Here, since solenoid valve 520 is opened, operation determination unit 400 sets predetermined object determination values to B1, B2, B _n−1 , and B _n . Subsequently, the object determination unit 430 has an absolute value of the rate of change (increase rate) of the voltage value that is equal to or smaller than the absolute value of the predetermined object determination value B2 and greater than the absolute value of the object determination value B1. Based on the above, it is determined that the object touching the touch detection electrode 200 is a water droplet, and the operation determination value is set to “β2”. According to the time chart shown in FIG. 19A, the absolute value of the change rate (decrease rate) of the voltage value is larger than the absolute value of the operation determination value β2, so that the operation determination unit 400 has the touch detection electrode 200. The touch switch detection device 100 accepts this operation and closes the electromagnetic valve 520 by determining that there is an operation by the user instead of a water drop.

  On the other hand, according to the time chart shown in FIG. 19B, after the electromagnetic valve 520 is opened by pressing the touch detection electrode 200 with a dry finger, a small amount of water droplets are attached to the touch detection electrode 200. In this case, as in the time chart shown in FIG. 19A, the operation determination unit 400 sets the operation determination value to “β2”, but the absolute value of the voltage value change rate (decrease rate) is determined as the operation determination. Since it is smaller than the absolute value of the value β2, it is determined that there is no operation by the user, and the touch switch detection device 100 does not accept this operation and does not close the electromagnetic valve 520.

  As described above, the operation determination unit 400 according to the present specific example sets the predetermined object determination value and the operation determination value depending on whether the electromagnetic valve is open or closed. Therefore, when the user removes the wet finger from the touch detection electrode 200, it is possible to perform a more accurate operation determination in consideration of the influence of water.

FIG. 20 is a flowchart illustrating still another specific example of the operation of the operation determination unit according to this embodiment.
First, based on the object determined by the object determination unit 430, the operation determination unit 400 has two operation determination values “Lα1 (first determination value), Hα1 (second determination value)”, “ “Lα2, Hα2”, “Lα _n−1 , Hα _n−1 ”, “Lα _n , Hα _n ” are set (step S504, step S506, step S508, step S510, step S512, step S514, step S516). . The absolute value of these operation determination values has the following relationship.

| Lα1 | <| Lα2 | <... <| Lα _n-1 | <| Lα _n | Equation (13)

| Hα1 | <| Hα2 | <... <| Hα _n−1 | <| Hα _n | Equation (14)

| Lα1 | <| Hα1 | Formula (15)

| Lα2 | <| Hα2 | Formula (16)

| Lα _n-1 | <| Hα _n-1 | Formula (17)

| Lα _n | <| Hα _n | Formula (18)

  Subsequently, the operation of the separation determination unit 420 shown in FIG. 16 determines whether or not a finger or the like has separated from the touch detection electrode 200 (step S518). If it is determined that the finger has separated (step S518: YES) ), It is determined whether or not the absolute value of the voltage value decrease rate (change rate) is between the absolute value of the operation determination value Lα and the absolute value of the operation determination value Hα (step S520). When the absolute value of the voltage value decrease rate (change rate) is between the absolute value of the operation determination value Lα and the absolute value of the operation determination value Hα (step S520: YES), the operation determination unit 400 Determines that there is no user operation, and the touch switch detection device 100 does not accept this operation (step S522). On the other hand, if the absolute value of the rate of decrease (change rate) of the voltage value is not between the absolute value of the operation determination value Lα and the absolute value of the operation determination value Hα (step S520: NO), the operation determination The unit 400 determines that there has been a user operation, and the touch switch detection device 100 accepts this operation (step S524).

Next, the operation of the operation determination unit of the present specific example will be further described with reference to a time chart corresponding to the operation of the flowchart shown in FIG.
FIG. 21 is a time chart for explaining a specific example of the operation of the operation determination unit of this specific example. FIG. 21A is a schematic diagram illustrating the voltage value when the touch detection electrode is pressed with a dry finger, and FIG. 21B is the voltage value when a water droplet is attached to the touch detection electrode. FIG. 21C is a schematic diagram illustrating the voltage value when the touch detection electrode is pressed with a wet finger.

  When an object comes into contact with the touch detection electrode 200 and the absolute value of the voltage value change rate (increase rate) is equal to or less than the absolute value of the predetermined object determination value A1, as shown in FIG. The object determination unit 430 determines that the object is a user's finger. Here, the operation determination unit 400 sets the operation determination value to “Lα1, Hα1” based on the object (user's finger) determined by the object determination unit 430.

  Subsequently, according to the change of the voltage value shown in FIG. 21A, the absolute value of the change rate (decrease rate) of the voltage value is the absolute value of the operation determination value Lα1 and the absolute value of the operation determination value Hα1. The operation determination unit 400 determines that there has been an operation by the user because the operation determination value Hα1 is larger than the absolute value of the operation determination value Hα1, and the touch switch detection device 100 accepts this operation.

  On the other hand, an object contacts the touch detection electrode 200, and as shown in FIG. 21B, the absolute value of the change rate (increase rate) of the voltage value is the absolute value of the predetermined object determination value A2. If it is equal to or less than the object determination value A1, the object determination unit 430 determines that the object is a water droplet. Here, the operation determination unit 400 sets the operation determination value to “Lα2, Hα2” based on the object (water droplet) determined by the object determination unit 430.

  Subsequently, according to the change of the voltage value shown in FIG. 21B, the absolute value of the change rate (decrease rate) of the voltage value is the absolute value of the operation determination value Lα2 and the absolute value of the operation determination value Hα2. Therefore, the operation determination unit 400 determines that there is no user operation, and the touch switch detection device 100 does not accept this operation.

  On the other hand, an object contacts the touch detection electrode 200, and as shown in FIG. 21C, the absolute value of the change rate (increase rate) of the voltage value is a predetermined object determination value A2. When the absolute value is equal to or smaller than the absolute value and larger than the absolute value of the object determination value A1, the object determination unit 430 determines that the object is a water droplet, as in the time chart shown in FIG. To do. Note that, in the time chart shown in FIG. 21C, a case where a water droplet attached to the finger falls on the touch detection electrode is illustrated as in the case described above with reference to FIG.

  Here, the operation determination unit 400 sets the operation determination value to “Lα2, Hα2” based on the object (water droplet) determined by the object determination unit 430. According to the voltage value change shown in FIG. 21C, the absolute value of the voltage value change rate (decrease rate) is between the absolute value of the operation determination value Lα2 and the absolute value of the operation determination value Hα2. However, since it is larger than the absolute value of the operation determination value Hα2, the operation determination unit 400 determines that there is an operation by the user, and the touch switch detection device 100 accepts this operation.

  As described above, the operation determination unit 400 of this specific example sets two operation determination values, large and small, and provides a certain width for the determination reference, so that the user presses the touch detection electrode 200 with a dry finger. It is possible to more accurately determine the case where the touch detection electrode 200 is pressed with a wet finger and the case where a water droplet is attached to the touch detection electrode 200. Therefore, it is possible to accurately determine whether the operation of the touch switch detection device 100 is due to a human operation or due to water droplet adhesion.

  FIG. 22 is a flowchart illustrating yet another specific example of the operation of the operation determination unit according to this embodiment. The operation of the operation determination unit illustrated in FIG. 22 is a combination of the operation of the operation determination unit illustrated in FIG. 18 and the operation of the operation determination unit illustrated in FIG.

In the flowchart shown in FIG. 22, the operation judgment values α1, α2, α _n−1 , α _n respectively set in step S418, step S420, step S422, and step S424 of the flowchart shown in FIG. The operation determination values “Lα1, Hα1”, “Lα2, Hα2”, “Lα _n−1 , Hα _n−1 ”, “Lα _n , Hα _n ” are respectively replaced with large and small operation determination values (step S618, step S620, step S620). S622, step S624). Similarly, the operation determination values β1, β2, β _n−1 , β _n set in step S432, step S434, step S436, and step S438 in the flowchart shown in FIG. The judgment values “Lβ1, Hβ1”, “Lβ2, Hβ2”, “Lβ _n−1 , Hβ _n−1 ”, “Lβ _n , Hβ _n ” are respectively replaced (Step S632, Step S634, Step S636, Step S638). ).

  Furthermore, the determination method in step S442 in the flowchart shown in FIG. 18 is based on the absolute value of the decrease rate (change rate) of the voltage value being the absolute value of the operation determination value Lα (β) and the operation determination value Hα (β). The method is replaced with a method of determining whether or not the absolute value is in between (step S642). When the absolute value of the decrease rate (change rate) of the voltage value is between the absolute value of the operation determination value Lα (β) and the absolute value of the operation determination value Hα (β) (step S642: YES). The operation determination unit 400 determines that there is no user operation, and the touch switch detection device 100 does not accept this operation. On the other hand, when the absolute value of the voltage value decrease rate (change rate) is not between the absolute value of the operation determination value Lα (β) and the absolute value of the operation determination value Hα (β) (step S642: NO), the operation determination unit 400 determines that there has been a user's operation, and the touch switch detection device 100 accepts this operation. Other operations are the same as those shown in FIG.

Next, the operation of the operation determination unit of this example will be further described with reference to a time chart corresponding to the operation of the flowchart shown in FIG.
FIG. 23 is a schematic view illustrating the voltage value when the electromagnetic valve is opened by pressing the touch detection electrode with a finger. FIG. 23A is a schematic diagram illustrating the voltage value when the touch detection electrode is pressed with a dry finger to open the solenoid valve and then pressed with a wet finger to close the solenoid valve. FIG. 23B is a schematic diagram illustrating voltage values when a minute amount of water droplets are attached to the touch detection electrode after the touch detection electrode is pressed with a dry finger to open the solenoid valve.

When the user presses the touch detection electrode 200 with a dry finger to open the electromagnetic valve 520, the electromagnetic valve 520 is closed, so that the operation determination unit 400 sets the predetermined object determination values to A1, A2, set to a _n-1, and _{a n.} Subsequently, the object determination unit 430 detects the object that has touched the touch detection electrode 200 based on the fact that the absolute value of the rate of change (increase rate) of the voltage value is equal to or less than the absolute value of the predetermined object determination value A1. Is determined to be a user's finger, and the operation determination value is set to “Lα1, Hα1”. According to the time chart shown in FIG. 23A, the absolute value of the voltage value decrease rate (change rate) is not between the absolute value of the operation determination value Lα1 and the absolute value of the operation determination value Hα1. Since it is larger than the operation determination value Hα1, it is determined that there has been an operation by the user, and the touch switch detection device 100 accepts this operation and closes the electromagnetic valve 520.

Here, since solenoid valve 520 is opened, operation determination unit 400 sets predetermined object determination values to B1, B2, B _n−1 , and B _n . Subsequently, the object determination unit 430 has an absolute value of the rate of change (increase rate) of the voltage value that is equal to or smaller than the absolute value of the predetermined object determination value B2 and greater than the absolute value of the object determination value B1. Based on the above, it is determined that the object in contact with the touch detection electrode 200 is a water droplet, and the operation determination value is set to “Lβ2, Hβ2.” According to the time chart shown in FIG. 23A, the absolute value of the voltage value decrease rate (change rate) is not between the absolute value of the operation determination value Lβ2 and the absolute value of the operation determination value Hβ2. Since it is larger than the operation determination value Hβ2, it is determined that there has been an operation by the user, and the touch switch detection device 100 accepts this operation and closes the electromagnetic valve 520.

  On the other hand, according to the time chart shown in FIG. 23B, after the touch detection electrode 200 is pressed with a dry finger to open the electromagnetic valve 520, a small amount of water droplets are attached to the touch detection electrode 200. In this case, as in the time chart shown in FIG. 23A, the operation determination unit 400 sets the operation determination value to “Lβ2, Hβ2,” but the absolute value of the voltage value change rate (decrease rate) is Since it is between the absolute value of the operation determination value Lβ2 and the absolute value of the operation determination value Hβ2, it is determined that there has been no operation by the user, and the touch switch detection device 100 does not accept this operation, Do not close.

  As described above, the operation determination unit 400 according to the present specific example performs the combined operation of the operation of the operation determination unit illustrated in FIG. 18 and the operation of the operation determination unit illustrated in FIG. It is possible to judge more clearly when the button is pressed and when a drop of water is attached, and more accurate use is possible by setting two large and small operation judgment values and providing a certain range for the judgment criteria. The presence or absence of the user's operation can be determined.

  As described above, according to the present embodiment, the operation determination value is set according to the object touching the touch detection electrode 200, the absolute value of the operation determination value, and the absolute value of the voltage value decrease rate , To determine whether the user has operated. Alternatively, two large and small operation determination values are set according to the object touching the touch detection electrode 200, and the absolute value of the two large and small operation determination values is compared with the absolute value of the voltage value decrease rate. To determine if there is any user operation. Accordingly, the operation determination unit 400 can more accurately determine when the user presses the touch detection electrode 200 with a dry finger, when the user presses the touch detection electrode 200 with a wet finger, and when a water droplet is attached to the touch detection electrode 200. Can be determined. Therefore, it is possible to accurately determine whether the operation of the touch switch detection device 100 is due to a human operation or due to water droplet adhesion.

The embodiment of the present invention has been described above. However, the present invention is not limited to these descriptions. As long as the features of the present invention are provided, those skilled in the art appropriately modified the design of the above-described embodiments are also included in the scope of the present invention. For example, in the description of the embodiment of the present invention, the voltage value of the detection output reflecting the change in the capacitance increases when the finger touches, and the voltage value decreases when the finger is released as an example. However, the present invention is not limited to this, and depending on the configuration of the detection circuit, the voltage value of the detection output can be lowered when the finger is touched, and the voltage value can be increased when the finger is removed.
Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

The block diagram of the touch switch detection apparatus concerning embodiment of this invention is represented. The block diagram of the water supply apparatus using the touch switch detection apparatus concerning this embodiment is represented. The schematic diagram of the water supply apparatus using the touch switch detection apparatus concerning this embodiment is represented. It is a graph showing the voltage value (actual measurement value) output from the detection part when a touch detection electrode is pushed with the dry finger. It is a graph showing the voltage value (actual measurement value) output from the detection part when a water droplet adheres to a touch detection electrode. It is a graph showing the voltage value (actual measurement value) output from the detection part when the touch detection electrode of this embodiment is pushed with the wet finger. It is a schematic diagram which illustrates the case where a touch detection electrode is pushed with the dry finger. It is a schematic diagram which illustrates the case where a water droplet adheres to the touch detection electrode. It is a schematic diagram which illustrates the case where a touch detection electrode is pushed with a wet finger. It is a schematic diagram showing the voltage value at the time of pushing a touch detection electrode with a wet finger. It is a schematic diagram which illustrates the case where a touch detection electrode is pushed with a wet finger. It is a schematic diagram showing the voltage value at the time of pushing a touch detection electrode with a wet finger. It is a schematic diagram which illustrates the case where the touch detection electrode with a water drop is pushed with a dry finger. It is a flowchart figure which illustrates the specific example of operation | movement of the operation determination part of this embodiment. It is a flowchart figure which illustrates the specific example of operation | movement of the target object judgment part of this embodiment. It is a flowchart figure which illustrates the specific example of operation | movement of the separation determination part of this embodiment. It is a time chart for demonstrating the specific example of operation | movement of the operation determination part of this specific example. It is a flowchart figure which illustrates the other specific example of operation | movement of the operation determination part of this embodiment. It is a schematic diagram which illustrates the voltage value at the time of pushing a touch detection electrode with a finger | toe and opening an electromagnetic valve. It is a flowchart figure which illustrates the other specific example of operation | movement of the operation determination part of this embodiment. It is a time chart for demonstrating the specific example of operation | movement of the operation determination part of this specific example. It is a flowchart figure which illustrates the other specific example of operation | movement of the operation determination part of this embodiment. It is a schematic diagram which illustrates the voltage value at the time of pushing a touch detection electrode with a finger | toe and opening an electromagnetic valve.

Explanation of symbols

100, 100a, 100b, 100c Touch switch detection device, 200 touch detection electrode, 300 detection unit, 310 oscillation unit, 320 voltage conversion unit, 400 operation determination unit, 420 separation determination unit, 430 object determination unit, 500 water supply device, 510 control unit, 520 solenoid valve, 530 water outlet

Claims (8)

A touch detection electrode that detects a change in capacitance due to a user's contact or separation; and
A detection unit that outputs a detection output reflecting the change in the capacitance;
An operation determination unit that determines the presence or absence of a user's operation based on the detection output;
With
The operation determination unit is
An object determination unit that determines an object that contacts the touch detection electrode based on whether or not a change rate of the detection output at the start of detection is equal to or less than a predetermined object determination value;
A separation determination unit that determines whether the user is separated based on whether the change rate of the detection output is equal to or greater than a predetermined separation value;
Have
The operation determination unit sets an operation determination value according to the object determined by the object determination unit, and the user's operation depends on whether the change rate of the detection output is equal to or higher than the operation determination value. A touch switch detection device characterized by determining the presence or absence of a touch switch.   The touch switch detection device according to claim 1, wherein when the change rate of the detection output is equal to or greater than the operation determination value, the operation determination unit determines that the user has operated. The operation judgment value is
A first operation determination value;
A second operation determination value that is larger than the first operation determination value;
The touch switch detection device according to claim 1, wherein the touch switch detection device is set to any one of the following.   When the change rate of the detection output is not between the first operation determination value and the second operation determination value, the operation determination unit determines that the user has operated. The touch switch detection device according to claim 3.   The operation determination unit, when the object determination unit determines that the object is a water droplet, the operation determination value that is larger than a value determined when the object is determined to be a contact of the user. The touch switch detection device according to claim 1, wherein the touch switch detection device is set. The touch switch detection device according to any one of claims 1 to 5,
A solenoid valve that opens and closes the water supply flow path;
A water discharge port for discharging water supplied through the water supply channel;
Based on the determination of the operation determination unit, a control unit that controls the operation of the solenoid valve;
A water supply apparatus comprising:   The water supply apparatus according to claim 6, wherein at least one of the predetermined object determination value and the operation determination value is changed according to an open / close state of the electromagnetic valve.   The said operation determination part sets the said predetermined target judgment value and the said operation judgment value which are a larger value when the said solenoid valve is an open state than the case where the said solenoid valve is a closed state, It is characterized by the above-mentioned. 7. The water supply apparatus according to 7.