JP2005252693A - Touch switch apparatus and touch switch method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch switch apparatus that is inexpensive and small and has simple circuit constitution, nonetheless has durability, and high sensitivity and reactivity, and to provide a touch switch method. <P>SOLUTION: The touch switch apparatus is provided with: a transformer 13 for stepping down an AC current inputted from a commercial power supply to prescribed voltage; a rectification circuit 15 for rectifying the AC current stepped down by the transformer 13; a smoothing circuit 16 for smoothing the pulsation of the AC current rectified by the rectification circuit 15; a touch member 17 which is connected to a GND of the AC current smoothed by the smoothing circuit 16 and with which a person can come into skin contact for operation; and a voltage change detecting means 18 for detecting voltage change between the GND of the smoothed AC current and HOT of AC current before stepped down. When the person comes into skin contact with the touch member 17, the voltage change detecting means 18 detects voltage change generated between the GND of the smoothed AC current and the HOT of the AC current before stepped down, and when there is change that is fixed voltage or more, a switch is made to operate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a touch switch device and a touch switch method that perform a switch operation when a person touches the skin.

2. Description of the Related Art Conventionally, so-called touch switches that output a current signal according to an input position on an image surface when touched with skin such as a finger have been widely used in ATMs of financial institutions, for example.
The touch switch has an excellent advantage that it can react instantly by lightly touching it, and can also serve as a display function when mounted on the entire display device.

  A typical example of taking advantage of such a touch switch is a capacitive touch switch. The capacitive touch switch is configured, for example, by providing a transparent conductive film having a predetermined surface resistance on the entire surface of a transparent substrate, and is mounted on the front surface of a display device such as a liquid crystal screen when used.

  Electrode terminals are provided on the peripheral edge of the transparent conductive film at a constant pitch, and the transparent conductive film and the touch position detection circuit are connected via the electrode terminals. When the skin such as a finger is brought into contact with an arbitrary point on the transparent conductive film, the transparent conductive film is grounded through the capacitance of the human body at the touched point, and the resistance between each electrode terminal and the ground line. A change occurs in the value. This change is detected by the touch position detection circuit, whereby the coordinates on the display device are input. Many ATMs of financial institutions adopt this structure.

  The capacitive touch switch is provided on a screen such as a liquid crystal and has a display function, and may be used as a simple switch without a display function. In this case, an opaque substrate is used. Is used, but other structures are almost common.

However, such a capacitive touch switch has the following problems.
That is, the above-described touch position detection circuit has a complicated circuit configuration, leading to an increase in cost, or an increase in the size of the device itself, thereby limiting its application. In particular, in the use of a switch that does not require a display function, a normal button type having a simple structure and a low cost occupies the majority, and a capacitive touch switch has hardly been used.

Further, unlike a normal button type switch, the touch switch has almost no reaction force at the time of pressing, so that a feeling of operation cannot be grasped and an excessive force is often applied at the time of operation.
By repeating the pressing force more than necessary, the conductive film of the substrate is easily deteriorated, and the sensitivity may be deteriorated at an early stage or malfunction may be caused. These durability problems can be solved to some extent by bonding and protecting another protective substrate on the substrate conductive film with an adhesive. On the other hand, however, the cost increases or the reaction rate decreases. Another problem has arisen.

  The present invention has been made in view of the above problems, and provides a touch switch device and a touch switch method that have a simple circuit configuration, a low cost and a small size, yet have durability, high sensitivity, and high reactivity. With the goal.

  In order to solve the above problem, the invention described in claim 1 includes a transformer that steps down an alternating current input from a commercial power supply to a predetermined voltage, a rectifier circuit that rectifies the alternating current stepped down by the transformer, A smoothing circuit that smoothes the pulsation of the direct current rectified by the rectifying circuit, a touch member that is connected to the GND of the direct current smoothed by the smoothing circuit and that can be touched by a human skin for operation; Between the smoothed GND of the direct current and the HOT of the alternating current before being stepped down, voltage change detecting means for detecting a voltage change is provided, and smoothing is performed when a person touches the touch member. The voltage change detection means detects a voltage change that occurs between the GND of the DC current that has been generated and the HOT of the AC current before being stepped down, and the switch operates when there is a change beyond a certain voltage.

  According to the invention of claim 1 configured as described above, the alternating current input from the commercial power source is stepped down to a predetermined voltage by the transformer, the alternating current stepped down by the transformer is rectified by the rectifier circuit, The pulsation of the direct current rectified by the rectifier circuit is smoothed by the smoothing circuit. On the other hand, a floating voltage is generated between the smoothed direct current GND and the alternating current HOT before being stepped down, and a person operating the touch member connected to the direct current GND When contacted, the floating voltage of the GND changes abruptly. The voltage change detection means detects a voltage change generated between the smoothed direct current GND and the alternating current HOT before being stepped down when a person makes skin contact with the touch member in this manner. The switch is activated when there is a change over voltage.

According to the second aspect of the present invention, a capacitor is provided between the smoothed direct current GND and the alternating current HOT before being stepped down.
According to the second aspect of the present invention configured as described above, a capacitor is provided between the GND and the HOT, and even if a voltage change occurs, a direct current component does not flow.

According to a third aspect of the present invention, the voltage change detecting means comprises a comparator or a differentiation circuit.
According to the invention described in claim 3 configured as described above, since the floating voltage is input to the comparator or the differentiation circuit, only a slight output is obtained for a gradual change, and the person touches the touch member. The output is greatly changed in response to a sudden change.

According to a fourth aspect of the present invention, the voltage change detecting means is provided between the GND of the DC current smoothed through the smoothing filter and the HOT of the AC current before being stepped down.
According to the fourth aspect of the present invention configured as described above, the minute change component in the floating voltage is almost ignored by the smoothing filter, and the voltage change detecting means reacts only to a sudden change that cannot be smoothed. Switch.

In Claim 5, the said touch member can be comprised with a metal plate.
According to the invention described in claim 5 configured as described above, for example, a metal plate is exposed to the outside, and a person touches the metal plate when operated. A simple metal plate will surely cause a change in stray voltage without being worn or damaged by human touch.

According to a sixth aspect of the present invention, the touch member is provided as a network access setting switch at a wireless LAN access point.
According to the invention described in claim 6 configured as described above, the wireless LAN access point is provided as a switch for some network access setting, and the operator touches the touch member when the user wants to perform the same setting. . When the touch member is touched, as described above, a steep change occurs in the floating voltage, and the voltage change detecting means switches. Network access is set using this switch operation.

The invention described in claim 7 is configured such that the touch member is provided in a display device.
According to the invention described in claim 7 configured as described above, the operator looks at the display on the display device, makes a determination, and touches the touch member to perform a necessary reaction. If the touch member is touched, a switch is activated to input a reaction.

The invention described in claim 8 is configured such that the display device is any one of a liquid crystal, a CRT, a PDP, and an organic EL.
According to the invention described in claim 8 configured as described above, a person can visually determine the display content displayed on any one of liquid crystal, CRT, PDP, and organic EL, and operate with a touch member. .

The invention described in claim 9 is such that the display device including the touch member is provided in an ATM of a financial institution.
When operating an ATM of a financial institution, it is necessary to input an account number, input an amount, confirmation of operation, etc., and human operation is required. According to the invention according to claim 9, configured as described above. When operating the ATM, it is judged by looking at the display on the display device, and the touch member is touched for operation.

As described above, the method using the floating voltage generated between the smoothed direct current GND and the alternating current HOT is not necessarily limited to a substantial device, and it can be easily understood that the method also functions. . For this reason, the invention according to claim 10 is a touch member that can be contacted with human skin by connecting an AC current input from a commercial power source to a predetermined voltage and connecting to a rectified and smoothed DC current GND. When a person touches the skin, a voltage change generated between the GND and the HOT of the alternating current before being stepped down is detected, and the switch is operated when there is a change exceeding a certain voltage.
That is, it is not necessarily limited to a substantial apparatus, and there is no difference that the method is also effective.

According to the invention described in claim 1 and claim 10 configured as described above, paying attention to the floating voltage generated between the smoothed direct current GND and the alternating current HOT generated when the transformer is used, the touch is performed. By utilizing the skin contact with the member, the touch switch device can be provided with an extremely simple configuration.
In addition, since the voltage change caused by skin contact occurs instantaneously, it has high sensitivity and reaction speed.
According to invention of Claim 2, when a person makes skin contact with the said touch member for operation, an electric current does not energize the said person and does not give discomfort.
According to the third aspect of the present invention, since the circuit configuration can be simplified by a simple and general detection means such as a comparator or a differential circuit, the cost and size can be reduced.
According to the invention described in claim 4, since the fluctuation of the floating voltage itself is absorbed by the smoothing filter, the malfunction of the voltage change detecting means can be reduced.

According to the fifth aspect of the present invention, the above-described effects can be obtained by a metal plate that can be easily obtained at low cost. Moreover, the risk of damage and the like can be greatly reduced.
According to the sixth aspect of the present invention, the wireless LAN network access setting work can be realized simply by touching the touch member, and even a person who cannot perform machine operation can easily feel the operation. In addition, since the metal plate is only exposed to the outside, it is difficult to break and is also effective in terms of design.
According to the invention described in claims 7 to 9, a robust operation input device is provided with a simple circuit configuration in a situation where a large number of people such as bank ATMs have to operate while looking at the display. be able to.

  Hereinafter, each embodiment embodying the present invention will be described.

FIG. 1 shows a touch switch device 11 in this embodiment.
As shown in the figure, in the touch switch device 11, for example, an AC current of 100 V as a commercial power input from the plug 12 is stepped down to, for example, 10 V through the transformer 13. The stepped-down alternating current is rectified by, for example, a bridge-type rectifier circuit 15, and then the pulsation is smoothed by the smoothing circuit 16.

AC current, which is a commercial power source, is generally supplied from two systems, HOT and GND. A touch switch 17 as a touch member to be described later is connected via a capacitor 14 to the HOT in the 100 V current before stepping down by the transformer 13 and the GND side of the smoothed DC current.
Further, a differential circuit 18 as a voltage change detecting means is provided between the capacitor 14 and the touch switch 17 via a filter 19.

  In this embodiment, the touch switch 17 is, for example, a setting switch provided in the access point that is necessary for network access setting when connecting to the wireless LAN via the access point.

  The touch switch 17 as the setting switch described above does not require a display function, and is made of a conductive metal plate such as aluminum, and is electrically connected to the above-described smoothed GND. When skin such as a finger is brought into contact with this metal plate touch switch 17, the smoothed GND is connected to the human body through the transparent conductive film, and the point a located between the smoothed GND and the HOT before step-down is provided. As shown in FIG. 2, a rapid voltage change occurs.

  The phenomenon that causes this voltage change has been newly found by the applicant in the process of research and development, but the detailed cause of such voltage fluctuation has not yet been fully elucidated. However, it has been found that it surely occurs as the human body touches the touch switch 17.

  The voltage waveform accompanied by the rapid voltage change shown in FIG. 2 generated between the smoothed GND and the HOT before stepping down due to the human skin contact, noise is removed through the filter 19, and as shown in FIG. , B is a smooth voltage waveform and is input to the differentiation circuit 18.

  Upon receiving the input, the differential circuit 18 triggers and outputs a differential waveform such as the point c shown in FIG. 4, and a voltage change is detected and used appropriately for switch operation via an individual control circuit (not shown). Then, network access setting processing when connecting to the wireless LAN through the access point is performed.

Since the voltage change occurs instantaneously with skin contact with the touch switch 17 of the human body, extremely fast switch operation control can be performed.
Further, since the touch switch 17 is made of a simple metal plate, unlike the conventional capacitive touch panel, there is no possibility that the sensitivity is lowered even if the touch switch 17 is repeatedly pressed.
Furthermore, since the touch switch 17 is made of a simple metal plate, the cost is extremely low.
Further, the differentiating circuit 18 is a very general circuit, and can detect a voltage change easily and inexpensively, and the touch switch device 11 can be configured at a low cost.
Furthermore, since the capacitor 14 is provided between the smoothed GND and the pre-step-down HOT, current does not flow to the human body side even when the human body touches the touch switch 17, and the electric current does not flow. It does not give pleasure.

  In addition, this invention is not limited to the structure of a present Example, It can change suitably about the structure listed below.

The voltage obtained by stepping down the commercial power supply is not limited to AC 10V, and may be other voltages such as 5V and 15V.
The display device can be applied to various other display devices regardless of the type as long as the touch switch device can be configured, such as a liquid crystal panel, a CRT display, a PDP, an organic EL, and the like.
The display panel is not necessarily required, and may be a touch member having no operation display function.
The voltage change detecting means is not limited to the differentiating circuit as in the present embodiment, and other detecting means can be applied as long as it is inexpensive and can detect the voltage change reliably. For example, a configuration using a comparator can be given.
○ The filter may be omitted.

The metal plate used for the touch switch is not limited to aluminum as in the present embodiment, and may be another conductive metal such as iron or copper.
The touch switch is not limited to a metal plate as in the present embodiment, and is configured by providing a transparent conductive film having a predetermined surface resistance on the entire surface of a transparent substrate, for example, on the front surface of a display device such as a liquid crystal screen. You may make it wear.
Further, a protective transparent substrate may be attached to the front surface side of the transparent substrate with a transparent adhesive as necessary to protect the transparent substrate.
Electrode terminals are provided at a constant pitch on the periphery of the transparent conductive film, and the transparent conductive film and the smoothed GND are connected via the electrode terminals. When skin such as a finger is brought into contact with an arbitrary point on the transparent conductive film, the smoothed GND is connected to the human body via the transparent conductive film, and thereafter functions in the same manner as in the case of the metal plate.

When the touch switch is provided in the display device, it is used for a display device provided in an ATM in a financial institution, for example, and also has an operation display function in a touch operation.
○ In addition, the voltage change occurs even if skin contact is made with a protective transparent substrate attached to the surface of the touch switch. Therefore, unlike conventional capacitive touch switches, the sensitivity decreases. There is no fear.
The specific structure of the touch switch is not limited to the case of using the metal plate described in this embodiment or the configuration using the transparent substrate having the transparent conductive film, and other structures can be appropriately employed.
In short, it is only necessary to be connected to the GND after smoothing and to cause a voltage change between the HOT before step-down and the GND after smoothing with human skin contact.

In the configuration using the transparent substrate having the transparent conductive film, the configuration may be such that a protective transparent substrate is not attached to the touch switch surface. In this case, the durability slightly decreases, but other excellent effects can be obtained in the same manner.
When the display device provided with the touch switch device is provided for ATM in a financial institution, glare light is generated on the surface of the display device, and the contrast ratio of the display is considerably reduced. The display may be difficult to read.
Therefore, a process for reducing the glare light may be separately performed on the protective transparent substrate provided on the surface of the display device.

○ The voltage change between HOT before step-down and GND after smoothing caused by skin contact with the touch switch of the human body is subtly depending on various conditions such as skin contact site, person, temperature, etc. Since they are different, the constant voltage serving as a reference for detecting the change is appropriately set according to the use conditions and is not particularly limited.
Also, the direction of change is not limited to either increase or decrease.

O The voltage change that occurs between the HOT before step-down and the GND after smoothing due to human skin contact is relatively small and may not be distinguishable from voltage changes caused by other factors such as noise. However, even in such a case, a voltage change associated with human skin contact is surely generated, so that it can be easily adopted in the above-described ATMs of financial institutions.
In other words, in ATM, even if it is activated by a voltage change due to noise or the like without being operated by a person, the insertion of a cash card or passbook, or a PIN number is functional. This is because the subsequent processing operation will not be performed unless this input operation is performed.
Of course, noise countermeasures, filters, and the like may be added to eliminate voltage changes caused by noise.
The configuration of the present embodiment may be configured as a touch switch method in addition to the touch switch device.

In the following, inventions (technical ideas) that can be grasped from the above-described embodiments other than those described in “Claims” are described.
(1) The touch switch device or the touch switch method according to claim 1, wherein a voltage obtained by stepping down an AC voltage input from the commercial power supply is 10V.
(2) The touch switch device according to any one of claims 7 to 8, wherein the touch member is formed by mounting a transparent substrate having a transparent conductive film over the entire surface of the display device.
(3) The voltage change between the smoothed direct current GND and the alternating current HOT before being stepped down when a person touches the touch member to perform an operation increases and decreases. The touch switch device or the touch switch method according to any one of claims 1 to 8, or (1) to (2).
(4) The touch switch device or the touch switch method according to (2), wherein a protective transparent substrate is attached to the front surface of the transparent substrate having the transparent conductive film.
(5) The transparent substrate for protection is subjected to glare light reduction processing.

  Provided are a touch switch device and a touch switch method that have a simple circuit configuration, low cost, and are small in size, durable, high in sensitivity and responsiveness.

1 is a schematic circuit diagram illustrating Example 1 of the present invention. It is a voltage waveform diagram explaining Example 1 of this invention. It is another voltage waveform diagram explaining Example 1 of the present invention. It is another voltage waveform diagram explaining Example 1 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Touch switch apparatus 12 ... Plug 13 ... Transformer 14 ... Capacitor 15 ... Rectifier circuit 16 ... Smoothing circuit 17 ... Touch switch as a touch member and a display device 18 ... Differential circuit as voltage change detection means 19 ... Filter

Claims (10)

A transformer that steps down alternating current input from a commercial power source to a predetermined voltage;
A rectifier circuit for rectifying the alternating current stepped down by the transformer;
A smoothing circuit for smoothing the pulsation of the direct current rectified by the rectifier circuit;
A touch member connected to the GND of the direct current smoothed by the smoothing circuit and capable of being touched by a human skin for operation;
Between the smoothed GND of the direct current and the HOT of the alternating current before being stepped down, voltage change detection means for detecting a voltage change is provided.
When a person makes skin contact with the touch member, the voltage change detection means detects a voltage change that occurs between the smoothed GND of the direct current and the HOT of the alternating current before being stepped down. A touch switch device, wherein the switch operates when there is a touch.   The touch switch device according to claim 1, wherein a capacitor is provided between the smoothed GND of the direct current and the HOT of the alternating current before being stepped down.   The touch switch device according to claim 1, wherein the voltage change detection unit includes a comparator or a differentiation circuit.   The said voltage change detection means is provided between GND of the direct current smoothed through the smoothing filter, and HOT of the alternating current before stepping down, The Claim 1-Claim 3 characterized by the above-mentioned. Touch switch device.   The touch switch device according to claim 1, wherein the touch member is a metal plate.   The touch switch device according to claim 1, wherein the touch member is provided as a network access setting switch at a wireless LAN access point.   The touch switch device according to claim 1, wherein the touch member is provided in a display device.   The touch switch device according to claim 7, wherein the display device is one of a liquid crystal, a CRT, a PDP, and an organic EL.   9. The touch switch device according to claim 7, wherein the display device including the touch member is provided in an ATM of a financial institution.   When a person touches the skin to a touch member that can touch the skin, which is connected to the rectified and smoothed GND of the direct current after stepping down the alternating current input from the commercial power source to a predetermined voltage, the GND A touch switch method comprising: detecting a voltage change generated between HOTs of an alternating current before being stepped down and switching the switch when a change of a certain voltage or more is detected.

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