JPH04207713A - Touch sensor device - Google Patents

Abstract

PURPOSE:To constitute a device so that even a beginner can execute surely the intended operation by constituting the device so that a driving signal is outputted by deciding definitely a detecting signal, and the definite decision of an input part is not executed for a prescribed time after the driving signal is outputted. CONSTITUTION:When a detecting signal is inputted, an output part 23 outputs a driving signal to a load driving part 4 by a definite decision with an input part 22. Simultaneously, in an input signal control part 24, the timer of a prescribed time is started. When this timer is in the course of counting, the input of the detecting signal is not executed in the input part 22. Therefore, even if a piezoelectric element 1 is pushed and a detecting circuit 2 outputs the detecting signal in the course of counting by the timer, the detecting signal is not received since a control part 21 is not in an input waiting state.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a touch sensor device using a piezoelectric element.

BACKGROUND OF THE INVENTION In recent years, various touch sensor devices have been devised and implemented. Some of these devices include those with contacts, those that use capacitance, and those that use pressure-sensitive elements whose impedance changes with pressure. In terms of reliability and price, touch sensors are not necessarily perfect, and the most appropriate type of touch sensor for the purpose of use is used.

Furthermore, the piezoelectric effect of a piezoelectric element that generates an electromotive force due to pressure is used in many fields, and has also been used as a touch sensor device.

Conventionally, touch sensor devices using this type of piezoelectric element are
The one shown in Figure 3 was common. The configuration will be explained below.

As shown in the figure, when the piezoelectric element 1 is touched, it generates an electromotive force, this electromotive force is detected by the detection circuit 2, and the control unit 3 inputting the detection signal is sent to the load drive unit 4 connected to the load. Outputs a drive signal to start or stop driving.

The electromotive force due to the piezoelectric effect of the piezoelectric element 1, which is typified by piezoelectric ceramic 7x, etc., varies over a wide range from several tens of mV to several tens of volts depending on the touch intensity, and the output waveform of the electromotive force also varies depending on the touch method and individual differences. The positive and frequency components were not determined, and the detected signal was extremely unstable. For this reason, the detection circuit 2 of the touch sensor device using the piezoelectric element 1 was constructed as shown in FIG. That is, a resistor 5 and a capacitor 6 are connected to both ends of the piezoelectric element 1, one end of the piezoelectric element 1 is grounded, and the other end of the piezoelectric element 1 is connected to a differentiating circuit 9 consisting of a capacitor 7 and a resistor 8. The cathode of a diode 10 whose anode is connected to the output of a) is connected to an integrating circuit 13 consisting of a resistor 11 and a capacitor 12, and the cathode of a Zener diode 140 is connected to the output of the integrating circuit 13.
The anode of 4 is grounded, the output of the integrating circuit 13 is input to the amplifier circuit 15 and amplified with a predetermined gain, and the output of the amplifier circuit 15 and a predetermined voltage are manually compared with the comparator circuit 16. .

With this detection circuit 2, the electromotive force generated by the piezoelectric element 1 is reduced to only a change in electromotive force by a differentiating circuit 9, and is rectified by a diode 10 to become only a positive side. This signal is stabilized by passing through the integrating circuit 13, and the amplifier circuit 1
5 with a predetermined gain. When the output exceeds a predetermined voltage value, the comparison circuit 16 outputs it as a detection signal.

The output signal of this detection circuit 2 was subjected to detection processing by a control section 3 as shown in FIG. The flowchart is shown in FIG. When the detection signal from the detection circuit 2 is output, the input section 17 of the control section 3 determines the detection signal. When the input section 17 confirms the determination, the output section 18 outputs a drive signal. The drive signal output from the output section 18 of the control section 3 is input to the load drive section 4, and processes such as starting or stopping driving of the load are performed. Then, it waited for the next detection signal input.

Problems to be Solved by the Invention In such conventional touch sensor devices, the polarity and frequency components of the output waveform of the electromotive force of the piezoelectric element 1 are not fixed due to the touch method and individual differences. In many cases, the detection signal is actually output more than once even though the user intended to do so. In other words, the piezoelectric element 1 at the moment when you first touch it with your finger
Even if it is detected by the electromotive force of It changed and the electromotive force was generated again. Furthermore, even if you intended to hit the ball only once, your finger may bounce and the detection signal may be output twice or more. In this way, two or more detection signals may be output by one touch.

To explain this point in detail, the voltage waveforms at each point of the 41ffiA to D when the electromotive force of the piezoelectric element 1 is generated by a human touch are shown in FIGS.
It is shown in Figures (A) to (D).

Figures 6 (A) to (D) are when the piezoelectric element 1 is touched as if hitting it, Figures 7 (A) to (D) are when the piezoelectric element 1 is touched, and Figure 8 (A) - (D) are the piezoelectric elements when touching the piezoelectric element 1 and releasing the finger when the finger is pressed unconsciously, and Fig. 9 (A) - (D) are the piezoelectric element when touching the piezoelectric element I and releasing the finger. These are voltage waveforms when a negative electromotive force is generated due to a change in stress to 1. The electromotive force generated by the piezoelectric element I by the detection circuit 2 of FIG. 4 is reduced to only a change in electromotive force by the differentiating circuit 9, and is rectified by the diode IO to become only on the positive side. This signal is stabilized by passing through the integrating circuit 13, and is amplified by the amplifier circuit 15 with a predetermined gain. When the output exceeds a predetermined voltage value, the comparison circuit 16 detects it as a detection signal. The voltage waveforms in Figures 6(D) and 7(D) are detection signals that are detected only once, but the voltage waveforms in Figures 8(D) and 9(C)
In D), the detection signal is output twice.

For this reason, devices equipped with conventional touch sensor devices sometimes malfunction against the user's intention.

FIG. 10 shows a faucet fitting as an application example of a device using a touch sensor device. This faucet fitting 19 is provided with a touch sensor device 20 at the tip of the fitting, and when the touch sensor device 20 is touched, water starts discharging, and when touched again, water is stopped. This device is extremely easy to operate and easy to use, as it can start and stop discharging water simply by touching the touch sensor device 20, unlike a faucet fitting that typically turns a faucet.

However, even if the touch sensor device 20 is touched to cause water to be discharged, the water discharge may remain in a stopped state, or
While discharging water, even if the user touches the touch sensor device 20 to stop discharging water, the water may continue to be discharged.

Therefore, there is a problem that the device may become inconvenient to use, such as requiring the user to get used to it.

The present invention solves the above-mentioned problems, and aims to provide a touch sensor device that is free from malfunctions due to the way the piezoelectric element is touched and is easy to use even for beginners.

Means for Solving the Problems In order to achieve the above object, the present invention includes a piezoelectric element, a detection circuit that detects the electromotive force of the piezoelectric element and outputs a detection signal, and a control circuit that outputs a drive signal based on the detection signal. Department and
A load driving section that drives a load using a drive signal from the control section, and the control section includes an input section that determines the detection signal, an output section that outputs the drive signal based on the determination of the detection signal, The problem solving means includes an input signal control section that does not determine the input section for a predetermined period of time after outputting the drive signal.

Function: According to the present invention, the load is driven once the piezoelectric element is touched by the above-mentioned means for solving the problem. After this,
By not detecting the input signal from the piezoelectric element for a predetermined period of time, it is possible to prevent malfunctions due to differences in human touch sense.

Example Hereinafter, one embodiment of the present invention will be described based on FIG.

Note that components having the same configuration as those of the conventional example are given the same reference numerals, and description thereof will be omitted.

As shown in the figure, the control unit 21 outputs a drive signal based on the detection signal of the detection circuit 2, and includes an input unit 22 that determines the detection signal, and an output unit 23 that outputs the drive signal based on the determination of the detection signal. , and a human power signal control section 24 that prevents the input section 22 from being established for a predetermined period of time after outputting the drive signal.

In the above configuration, the operation of the control unit 21 when the detection signals shown in FIGS. 6(D) to 9(D) are inputted from the detection circuit 2 will be described with reference to FIG. 2.

First, the human power section 22 waits for a detection signal from the detection circuit 2. When the detection signal is input, the input section 22
As a result of the determination, the output section 23 outputs a drive signal to the load drive section 4. At the same time, the input signal control section 24 starts a timer for a predetermined time.

While this timer is counting, no detection signal is input to the input section 22. When the predetermined time has elapsed and the timer counts up, the input section 22 waits for a detection signal again. Therefore, even if the piezoelectric element 1 is pressed while the timer is counting and the detection circuit 2 outputs a detection signal, the input section 22 of the control section 21 is not in an input standby state and does not receive the detection signal. That is, two or more consecutive detection signals are regarded as only one detection signal.

When the detection signal of the detection circuit 2 is generated only once as shown in FIG. 6(D) or FIG. 7(D), the control section 21 outputs the drive signal and waits for the next detection signal. If the detection signal is input two or more times in a row as shown in Figure 8 (D) or Figure 9 (D), the timer is still counting, so
No input confirmation is performed, and the detection signal is ignored within a predetermined time. When the piezoelectric element 1 is pressed again and a detection signal is input, if a predetermined time has already elapsed, the input is confirmed.

Here, the predetermined time of the timer may be about 0.7 seconds, since the human touch time is generally several hundred square meters, and the device can be used without any discomfort. However, it is not limited to this time in particular, and may be set to an appropriate value depending on the device.

Furthermore, since the control section 21 does not require the addition of any particular circuit and only changes the processing method of the control section 21, it is possible to change not only the program of the microcomputer used in the device, but also extremely useful. A highly effective detection method can be easily obtained.

In this way, even if a detection signal that is continuously input is manually input without being influenced by the human touch sense, which has large individual differences, it is processed as a single detection signal within a predetermined time, so no one can detect it. There is no need to get used to the operation, and even beginners can reliably perform the intended operation.

In addition, the faucet fitting shown in Fig. 10 starts discharging water when the touch sensor 20 is touched while discharging water is stopped, and stops discharging water when the touch sensor 20 is touched during discharging water. Even if a detection signal is detected twice or more, it is processed as a single detection signal. Therefore, when trying to start discharging water, it will not malfunction and return to the stopped state again, and similarly, when trying to stop water dispensing, it will not return to the dispensing state again, and the The operation can be ensured.

When an ill valve that opens and closes a waterway is used as a load, the equipment has a durable life, or the load does not repeatedly start and stop driving within a predetermined time set by a timer, so the equipment has a durable life. In this case, since unnecessary driving is not performed, its durability can be improved.

In addition, since the load is a solenoid valve that opens and closes the waterway, the frequency of damage to the waterway system due to water hammer, etc. can be kept to the necessary minimum, and there is less negative impact on other connected equipment.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the control section includes an input section for determining a detection signal, an output section for outputting a drive signal based on the determination of the detection signal, and an output section for outputting a drive signal. Since the input signal controller is configured to not confirm the input part for a predetermined period of time after the detection, the detection signal can be continuously input without being influenced by human touch illusions, which have large individual differences. Even if a
There is no need for getting used to it, even a beginner can reliably perform the intended operation, and the device is extremely easy to use.

In addition, if the load does not repeatedly start and stop driving within the predetermined time of the input signal control unit and the equipment used has the durable life, unnecessary driving will not be performed, so the durability can be improved. can be improved.

Furthermore, in equipment where the load is to open and close the waterway using a solenoid valve, the frequency of water hammer movement of the waterway system can be reduced to the necessary minimum, and this has the effect of reducing the negative impact on other equipment that is sustained. There is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a touch sensor device according to an embodiment of the present invention, FIG. 2 is a flow chart of the same touch sensor device,
FIG. 3 is a block diagram of a conventional touch sensor device, FIG. 4 is a circuit diagram of a detection circuit of the same touch sensor device, FIG. 5 is a flowchart of the same touch sensor device, and FIGS.
D) to FIG. 9(A) to (D) are voltage waveform diagrams of main parts of the detection circuit when the piezoelectric element of the same touch sensor device is touched, respectively, and FIG. 10 is a perspective view of an application example of the same touch sensor device. It is a diagram. l...piezoelectric element, 2...detection circuit, 4
...Load drive unit, 21...Control unit, 2
2...Input section, 23...Output section, 24
...Input signal control section. Name of agent: Patent attorney Akira Okaji and two others 111 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] a piezoelectric element, a detection circuit that detects an electromotive force of the piezoelectric element and outputs a detection signal, a control section that outputs a drive signal based on the detection signal, and a load drive section that drives a load using the drive signal of the control section. The control unit includes an input unit that determines the detection signal, an output unit that outputs the drive signal upon determination of the detection signal, and an input unit that outputs the drive signal for a predetermined period of time after outputting the drive signal. A touch sensor device comprising an input signal control section that prevents the determination of the input signal.