JP2003304147A - Touch switch with misoperation prevention - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch switch with misoperation prevention for preventing this equipment from being affected even when operating the equipment once by using a touch switch, and then operating it again, and for making it possible to operate the touch switch again in accordance with a reset signal. <P>SOLUTION: This touch switch with misoperation prevention is configured of a human body sensing part 2, a human body detecting part 1 for detecting the change of stray capacitance according as a part of a human body is brought into contact with the human body sensing part, and for transmitting an output, and a control circuit 3 for outputting a driving signal to a load when the output from the human body detecting part is inputted, and any inhibit signal is not inputted, and for inhibiting the driving signal to the load when the inhibit signal is inputted. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a touch switch that is turned on as a switch when a human body touches it, and by receiving a control signal, a load can be operated even when carelessly touched when it is not needed. The present invention relates to a touch switch with malfunction prevention that is not provided.

[0002]

2. Description of the Related Art Currently, as switches used in various devices, there are push switches, wave switches, and slide switches that are turned on and off by performing a pressing operation, and are turned on by performing a tilting operation. -There are toggle switches, knife switches, etc. that are turned off, and all of them are to physically contact the switch contacts to obtain conduction.

By the way, in the above-mentioned physical switch, after operating the switch for operating the device, the switch should not be operated during the operation of the device until the operation is completed. Locks the switch so that it cannot be operated physically, provides a barrier to prevent accidental operation when clothes are caught on it, and covers the switch operation part so that it cannot be operated. I was doing.

Further, in recent years, a part of a human body (finger) is touched with a metal plate, the induction of a commercial power source to the human body is used, or the change in the stray capacitance due to the approach of the human body is used. A touch switch that controls the on / off of the vehicle was developed, and by operating this touch switch, the lighting equipment was turned on / off or the stop floor number of the elevator was instructed.

[0005]

By the way, in the above-mentioned conventional physical switch, when the switch operation is prohibited again, the switch is physically locked, so that the structure of the switch is complicated. Therefore, the cost of the switch becomes high, and in the case of a switch that covers the lid, a malfunction occurs such that the lid is artificially opened and the switch is operated to stop the device.

[0006] In addition, there is no touch switch that has been used in such a manner that the switch is touched once and then touched again without affecting the operation of the device, and it is simply used as an on / off switch. There wasn't.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to use a touch switch to operate the device once and then operate the device again, and then to operate the device again. Another object of the present invention is to provide a touch switch with erroneous operation prevention that prevents the influence on the touch switch and allows the touch switch to be operated again by a reset signal.

[0008]

The touch switch with erroneous operation prevention of the present invention is intended to achieve the above-mentioned object.
The means of claim 1 includes a human body sensing unit, a human body detecting unit that detects a change in stray capacitance when a part of the human body touches the human body sensing unit, and outputs the output, and an output from the human body sensing unit. Is inputted and the inhibit signal is not inputted, the drive signal to the load is outputted, and when the inhibit signal is inputted, the control circuit for inhibiting the drive signal to the load is constituted. .

The means of claim 2 is characterized in that the control circuit also receives an inhibit signal and a reset signal for returning the switch to the initial state, and the means of claim 3 is different depending on the prohibition and permission output from the control circuit. It is characterized in that it is provided with a status indicator for displaying colors.

According to a fourth aspect of the present invention, the human body detecting unit oscillates a repetitive pulse signal, and a differential circuit type reactance attenuator that outputs a signal lacking the repetitive pulse when the human body touches the sensing unit. And a miss pulse detection circuit that outputs an output indicating that a human body touches the sensing unit by detecting the missing signal.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a human body detection unit 1 which detects that a part of a human body (finger or the like) is touched and outputs an output will be described with reference to FIGS. 1 and 2. In FIG. 1, 1
1 is the two inverters 11a and 11b shown in FIG.
The oscillation circuit composed of the resistor R1 and the capacitor C1 and the waveform shaping circuit composed of the inverter 12c shown in FIG. 2 (a) are used to generate a rectangular wave in the oscillation circuit 11. The reason is that a slight change in the stray capacitance is captured. This is because it is necessary to include high-order harmonics. However, in order to keep the contained spectrum as low as possible, the repetition frequency of the original vibration is brought to the midrange of the audible frequency.

Reference numeral 13 is a capacitor C2 shown in FIG.
It is a differential circuit type reactance attenuator composed of C3 and a resistor R2, and includes a human body sensing unit 2 described later. Here, the reason why the differentiating circuit is selected is to extract the high-order harmonics included in the original vibration, and the biggest reason for having such a circuit configuration is to capture a slight change in the stray capacitance at a high frequency. A region signal is required, but human motion is on the order of 0.1 seconds.

Therefore, a large amount of energy such as continuous high frequency is not necessary, and it is only necessary to intermittently take out a potential that exceeds the threshold of the gate 13a in the next stage, as shown in FIGS. 2 (c) and 2 (d). Therefore, the thinning pulse containing the high frequency component is extracted from the rectangular wave in the audio midrange and is repeatedly used by using the differentiating circuit. And
With such a circuit configuration, energy is extremely reduced as compared with a continuous high frequency signal.

In FIG. 1, reference numeral 2 denotes a human body (finger) sensing portion, and the electric field strength from the induction of a commercial power source guided to the human body to the broadcast radio wave has a great difference depending on the place, and malfunctions depending on the place of use. In order to prevent this from happening, the surface of the metal plate is insulated with paint or an insulating film so that the human body does not directly touch the metal plate (conductor). This sensing unit 2
Is connected between the midpoint of capacitors C2 and C3 in FIG. 2 (c) and ground.

In the differential circuit type reactance attenuator 13 of FIG. 2 (d), when the human body (finger) touches the sensing unit 2, 2
The stray capacitance at the midpoint of the two capacitors C2 and C3 increases. Therefore, the reactance of this portion decreases, and the differential waveform of the output in the figure is attenuated. What is important here is that it is necessary to set the value of the capacitor so that the differential waveform that has undergone this attenuation falls below the threshold value of the next stage gate 13a. As a result, when the finger touches the sensing unit 2, the next-stage gate 13a is not driven, so that the output does not appear.

Reference numeral 14 is a transistor T shown in FIG.
r, resistor R3, capacitor C4 and inverter 14a
The base of the transistor Tr is connected to the differential circuit type reactance attenuator 13 and is inverted and amplified in the inverter 14a.

The differential pulse of the differential circuit type reactance attenuator 13 is inputted to the base of the transistor Tr in the miss pulse detection circuit 14 as shown in FIG. 2 (e). Here, during the period I until the sensing unit 2 is touched by a finger, the capacitor C4 is charged via the resistor R3.

However, since the time constant of the capacitor C4 and the resistor R3 is set to be sufficiently larger than the pulse repetition time, the voltage across the capacitor C4 is the threshold of the inverter 14a as shown in (e) b. It is discharged by the transistor Tr with each pulse without reaching the maximum. Therefore, the output from the inverter 14a maintains a high level.

Then, when a finger is touched on the sensing section 2 in this state, the pulse from the differential circuit type reactance attenuator 13 is interrupted, so that the capacitor C4 is connected to the power source voltage as shown by the waveform b in the section II of FIG. 2 (e). Is charged up. Then, when the potential of the capacitor C4 exceeds the threshold value, the zero potential output is sent from the inverter 14a. The fact that the potential of this output changes from the power supply voltage to the common level is an output signal of the human body detection unit 1 when the sensing unit 2 is touched with a finger.

In FIG. 1, reference numeral 3 denotes a control circuit for controlling whether to output the output for driving the load 4 or to inhibit it by an inhibit signal when the output from the human body detecting section 1 is inputted, Reference numeral 31 is a control signal input circuit for sending an inhibit signal for not driving the load 4 even if it contacts the sensing portion 2, a control signal input circuit for sending the inhibit signal and a reset signal for returning the switch to an initial state, and 32 is a control signal input circuit. When a high-level inhibit signal is input from 31, the miss pulse detection circuit 1
The low-level signal from 4 passes through the AND gate, and when the low-level inhibit signal is input from the control signal input circuit 31, the signal from the miss pulse detection circuit 14 is cut off and a high-level constant signal is sent out. A positive logic NAND gate 33 is a flip-flop in which a high level output is alternately output to Q and bar Q each time the signal of the NAND gate 32 changes from low level to high level.

Numeral 5 is lit when a high level output is sent from the flip-flop 33, for example, a display comprising red and green LEDs, and when the green LED is lit, the load is It is in a standby state in which it is not driven. In this state, touching the sensing unit 2 drives the load, and touching the sensing unit 2 again stops the load and enters the standby state again to drive the load again. It shows the state that it is possible to do, and lights up green. If both the red and green LEDs are lit (visually orange),
The load is driven, and when only the red LED is lit, the inhibit signal is input and touching the sensing unit 2 does not affect the load.

It should be noted that the above-mentioned display 5 is the LE of the red portion.
It also serves as a control status indicator for displaying whether or not it is in the inhibit status together with the OR gate by using D. Also,
Reference numeral 6 is a confirmation sound generator that outputs a high level output from the flip-flop 33 to an electronic buzzer or an oscillating circuit that produces a sound and sounds a speaker.

Next, the overall operation will be described with reference to FIG.
First, the oscillation circuit 11 outputs a repetitive pulse signal of less than 1 KHz, and the pulse signal is waveform-shaped by the waveform shaping circuit 12 and then the differential circuit type reactance attenuator 1 is formed.
Input to 3. When the finger of the human body is not in contact with the sensing unit 2, the differential signal obtained by differentiating the pulse signal is inverted and amplified and shaped by the inverter 13a and is input to the miss pulse detection circuit 14, and the miss pulse detection circuit 14 is supplied. Outputs a high level voltage with no output, so that the load is not driven and the display 5 and the confirmation sound generator 6 are not driven.

On the other hand, when the human body (finger) touches the sensing unit 2,
Since the repetitive pulse from the differential circuit type reactance attenuator 13 is missing, the miss pulse detection circuit 14 sends an output with zero potential output, so that the load is driven, the display 5 is turned on, and the confirmation sound generator 6 is activated. Generates a confirmation sound.

The case where the high frequency energy is reduced by the differentiating circuit in the human body detecting section 1 has been described. However, as another method, as shown in FIG. The high frequency energy may be reduced by repeating a burst signal for about 0.1 seconds to cope with a small change in the stray capacitance.

Also, the waveform from the miss pulse detection circuit 14 and the output signal of the waveform c in FIG. 2 (e) can be used as a momentary switch.
A D-type flip-flop is added to the toggle switch as in the present embodiment, and a device called a photo MOS is driven to act as an AC touch switch. Further, the D-type flip-flop and the photo MOS are added. It is also possible to manufacture a wide variety of switches by various combinations such as configuring a toggle switch for alternating current.

Then, when the indicator 5 is illuminated in green (the load is stopped), the output from the miss pulse detection circuit 14 touching the sensing section 2 is at a low level, and the control signal is output. When the low level inhibit signal is not input to the AND gate 32 from the input circuit 31, a high level signal is output from the AND gate 32, and the flip-flop 33 outputs a high level output indicating that the state has changed. Since it is sent, the load 4 is energized. In this state, the display 5 turns orange.

If the display 5 is illuminated in orange (the load is in a driving state), the flip-flop 3
Since 3 outputs a low level output indicating that the state has changed, the load 4 changes to the stopped state. That is, the state is changed. Then, the indicator 5 is illuminated in green.

On the other hand, when the indicator 5 is illuminated in red, that is, when the inhibit signal of the low level is input from the control signal input circuit 31 to the AND gate 32, the sensing unit 2 is touched to the above. Even if the output from the miss pulse detection circuit 14 changes to the low level, the output from the AND gate 32 does not change and remains at the high level. Therefore, the flip-flop 33 continues the drive state when the load 4 is in the drive state. If the load 4 is in a stopped state, the load 4 is not driven. That is, the state is not changed.

If the control output input circuit 31 inputs a reset signal to the reset terminal of the flip-flop 33 when the display 5 is illuminated in orange (the load 4 is in a driving state), the flip-flop is turned on. When the display 33 is in the original state and the load is stopped, the indicator 5 lights up in green and the sensor 4 is touched, so that the load 4 can be controlled again.

As an application example of the touch switch with erroneous operation prevention, for example, when it is used as a touch switch for instructing the stop floor of an elevator, the inhibit signal input of the touch switch indicating the floor where the stop is to be prohibited is set to low level. By doing so, the status indicator 5 incorporated in the touch switch lights up red. Then, even if the touch switch is touched in this state, the elevator does not stop at the floor where the stop is prohibited from the above-mentioned operation. Since the touch switch is composed of an electronic circuit, it is possible to set a desired stop prohibition floor number by remote control using a communication line.

As another example, when applied to a production line, the control of the production line is generally controlled by a computer, but the control sequence can be programmed at the programming stage. At the stage of installation and operation on the line, the equipment is taught the timing etc. while watching the actual movement by manual operation. At this time, by changing the inhibit signal to the high level and releasing the prohibition only for the switch that needs to be operated according to the program, the display of that switch also turns green, so even if you accidentally touch another switch, you will be guided by the program. Since it does not detect, the equipment can be learned without fail and in order.

In the above-described embodiment, the structure of the human body detecting section 1 is an example, and it is of course possible to use a known touch switch.
In the above-mentioned embodiment, the logic circuit is shown, but it is also possible to replace it with a microprocessor or a programmable gate array (PLD).

[0034]

As described above, according to the present invention, when an output from the human body detecting unit which detects a change in the stray capacitance due to a part of the human body touching the human body detecting unit and outputs the output, The control circuit outputs the drive signal to the load when the inhibit signal is not input, and prohibits the drive signal to the load when the inhibit signal is input. Then, after operating once to operate the equipment, even if it is operated again, the inhibit signal does not affect the equipment, and the control circuit also accepts the inhibit signal and the reset signal for returning the switch to the initial state. I did so,
The reset signal also has the effect of stopping the operation of the device.

[Brief description of drawings]

FIG. 1 is a block diagram of a touch switch with erroneous operation prevention according to the present invention.

FIG. 2 is a circuit diagram and a waveform diagram for explaining the operation of the human body detection unit of the block of the above.

[Explanation of symbols]

1 Human body detection unit 11 oscillator circuit 12 Wave shaping circuit 13 Differential circuit type reactance attenuator 14 Miss pulse detection circuit 2 Human body detector 3 control circuit 31 Control signal input circuit 32 Nand Gate 33 flip-flops 4 load 5 Display 6 Confirmation voice generator

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5G034 AE07                 5G046 AB01 AC25 AD12 AD23 AE04                       AE09                 5J050 AA11 BB22 BB23 CC18 DD04                       EE02 EE28 EE31 EE34 EE36                       EE37 FF25 FF35

Claims (4)

[Claims] 1. A human body detection unit, a human body detection unit that detects a change in stray capacitance when a part of the human body touches the human body detection unit and sends an output, and an output from the human body detection unit is input. And a control circuit that outputs a drive signal to the load when the inhibit signal is not input and prohibits the drive signal to the load when the inhibit signal is input. Touch switch with erroneous operation prevention. 2. The touch switch with erroneous operation prevention according to claim 1, wherein the control circuit also receives an inhibit signal and a reset signal for returning the switch to an initial state. 3. The touch switch with erroneous operation prevention according to claim 1, further comprising a status indicator that displays different colors depending on prohibition and permission outputs from the control circuit. 4. The human body detecting unit includes an oscillation circuit that oscillates a repetitive pulse signal, a differential circuit type reactance attenuator that outputs a signal in which the repetitive pulse is missing when the human body touches the sensing unit, and the missing unit. 2. The touch switch with erroneous operation prevention according to claim 1, further comprising a miss pulse detection circuit that outputs an output indicating that a human body touches the sensing unit by detecting a signal.