KR100666699B1 - Electrical contact sensor and human interface device using the same - Google Patents

Abstract

The present invention discloses an electrical contact sensor and a human interface device using the same. The electrical contact sensor includes a reference signal generator for generating a reference signal, a first signal generator for delaying the reference signal to generate a first signal, and a contact pad. A second signal generator for delaying the signal more than the first signal and generating a second signal by delaying the reference signal smaller than the first signal when not in contact, and synchronizing the first signal with the second signal generator; And a contact signal generator for receiving a signal and generating a contact signal. Therefore, even if the conductivity is not sufficient, it is possible to accurately determine the presence or absence of a contact object having a predetermined charge accumulation ability to provide reliability of operation. In addition, it is possible to determine the contact of the contact object with only one contact pad, thereby reducing the layout of the product.

Description

Electrical touch sensor and human interface device using it

Is a circuit diagram of an electrical contact sensor according to the prior art;

FIG. 1B is an operation circuit diagram when the contact object is not in contact with the electrical contact sensor of FIG.

1C is an operation circuit diagram when a contact object is touched in the electrical contact sensor of FIG. 1A;

2 is a view showing a change in the output level of the electrical contact sensor in the electrical contact sensor of FIG.

3 is a block diagram of an electrical contact sensor in accordance with the techniques of the present invention.

4 shows a circuit diagram of an electrical contact sensor in accordance with the teachings of the present invention.

FIG. 5A is an operation circuit diagram when the contact object is not in contact with the electrical contact sensor of FIG. 4. FIG.

FIG. 5B is a diagram illustrating signal waveforms when the contact object is not in contact with the electrical contact sensor of FIG. 4; FIG.

FIG. 5C is an operation circuit diagram when a contact object contacts the electrical contact sensor of FIG. 4. FIG.

FIG. 5D illustrates a signal waveform diagram when a contact object contacts the electrical contact sensor of FIG. 4. FIG.

Figure 6 shows a first embodiment of a mouse using the electrical contact sensor of the present invention.

7 is a diagram illustrating a method of controlling operation power of the mouse of FIG. 6.

Fig. 8A shows a second embodiment of a mouse using the electrical contact sensor of the present invention.

FIG. 8B illustrates an arrangement of contact pads connected to the electrical contact sensor of FIG. 8A. FIG.

Fig. 9A shows a first embodiment of a portable device using the electrical contact sensor of the present invention.

Fig. 9B shows a second embodiment of a portable device using the electrical contact sensor of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch sensor, and more particularly, to an electrical contact sensor that electrically detects and notifies the presence or absence of a contact object and a human interface device using the same.

In general, the touch sensor is divided into a push button operating in a mechanical manner and an electrical contact sensor operating in a non-mechanical manner.

While the pushbuttons are inexpensive to produce, they require mechanical contacts to detect the selection of contact objects and spring devices for the resiliency of the buttons. Electrical contact sensors offer higher production costs than pushbuttons, but offer advantages over miniaturization.

Of particular interest in the present invention relates to electrical contact sensors.

1A to 1C are circuit diagrams of an electrical contact sensor according to the related art.

FIG. 1A is a basic circuit diagram of an electrical contact sensor, FIG. 1B is an operation circuit diagram of the electrical contact sensor when the contact object is not in contact, and FIG. 1C is an operation circuit diagram of the electrical contact sensor when the contact object is in contact.

With continued reference to FIG. 1A, the electrical contact sensor includes two contact pads (or contact pins) PAD1 and PAD2 with which a contact object is contacted, and a first resistor for protecting the internal circuit from static electricity transmitted from the contact object. (R1), the active element N-type FET Q1, the second resistor R2 for setting the bias voltage of the N-type FET Q1, and the third to be a load of the N-type FET Q1. A resistor RL and an output buffer B1 for buffering the output voltage of the N-type FET Q1 are provided.

If a contact object does not contact such an electrical contact sensor, as shown in the circuit diagram of FIG. 1B, the contact pads PAD1 and PAD2 are opened, so that the gate of the N-type FET Q1 is connected to the second resistor R2. Is connected to ground voltage.

The N-type FET Q1 connected with the ground voltage and the gate is turned off, and there is no flow of current through the N-type FET Q1 and the third resistor RL. The power supply voltage VDD is applied to the drain of the N-type FET Q1, and the output buffer B1 receives the power supply voltage VDD applied to the drain of the N-type FET Q1 to generate a "H" signal. To print.

On the other hand, when the contact object is in contact with the electrical contact sensor, the electrical contact sensor has the operation circuit diagram of Figure 1c.

The contact object at this time becomes a human finger which is generally a conductive resistor.

Referring to FIG. 1C, two contact pads PAD1 and PAD2 are connected through a resistor RH and are connected by a voltage difference between the power supply voltage VDD and the ground voltage VGND through the resistor RH. The generated current flows. Hereinafter, the resistor RH of a person connected to the contact pad will be referred to as a fourth resistor RH.

Then, a voltage of "power supply voltage VDD x second resistor R2 / (first resistor R1 + fourth resistor RH)" is applied to the gate of the N-type FET Q1.

When the voltage applied to the gate of the N-type FET Q1 is greater than the threshold voltage (Vth) of the N-type FET Q1, the N-type FET Q1 is turned on and the N-type FET Q1 is turned on. The drain current IL of "A x (VG-Vth) 2" flows through the third resistor RL. Where A is the intrinsic constant value of each FET and Vth is the threshold voltage value of each FET.

That is, the voltage VD of "power supply voltage VDD-drain current IL x third resistor RL" is applied to the drain of the N-type FET Q1.

In particular, when a voltage is applied to the gate of the N-type FET Q1, a drain current IL, which is calculated as "drain current IL x third resistor RL> power supply voltage VDD," is applied. The drain voltage of (Q1) becomes "0".

As described above, when two contact pads PAD1 and PAD2 come into contact with a sufficiently small resistance value, a drain voltage having a value close to "0" is generated in the drain of the N-type FET Q1. The drain voltage is output as an "L" signal via the output buffer B1.

As described above, the conventional electrical contact sensor includes two contact pads, and when a conductive contact object contacts the two contact pads at the same time, it electrically detects and generates and outputs a signal accordingly.

Conventional electrical contact sensors can be applied to various electrical and electronic devices by converting the contact facts into electrical signals with pure electrical contact without any mechanical configuration, but two contact pads are required to detect the contact of the contact object. It was.

Accordingly, the conventional electrical contact sensor has to be provided with two contact pads, so there is a limit of miniaturization.

In addition, the conventional electrical contact sensor detects the contact by using a resistance component generated in the human body, and therefore, a contact object contacting two contact pads must be an object having a constant resistance component.

When a person's finger is in contact with the electrical contact pad, but the person wears a non-conductive glove or the bare surface is dry and does not have sufficient conductivity, the electrical contact sensor is shown in FIG. 2. The same output signal is generated.

That is, when the contact object does not have sufficient conductivity despite the contact object contacting the contact pads PAD1 and PAD2 (section 1, section 3), the contact pads PAD1 and PAD2 are very sensitive. The state in which the resistor having the high resistance value is connected is in the same state. Accordingly, only a small current is applied to the N-type FET Q1 so that the electrical contact sensor generates an "H" signal.

As described above, in the case of the conventional electrical contact sensor, even though the contact object is in contact, when the contact object does not have sufficient conductivity, the electrical contact sensor may not detect this and malfunction.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrical contact sensor that can detect a contact even when a contact object having insufficient conductivity is touched.

Another object of the present invention is to provide an electrical contact sensor capable of detecting the presence or absence of contact of a contact object with only one contact pad.

Still another object of the present invention is to provide a human interface device using an electrical contact sensor.

The electrical contact sensor of the present invention for achieving the above and other objects has a reference signal generator for generating a reference signal, a first signal generator for delaying the reference signal to generate a first signal, and a contact pad And a second signal generator for delaying the reference signal more than the first signal when the contact pad is in contact, and generating the second signal by delaying the reference signal smaller than the first signal when not in contact. And a contact signal generator for receiving the second signal in synchronization with the first signal and generating a contact signal.

According to another aspect of the present invention, there is provided a human interface device including a contact pad, at least one electrical contact sensor for generating a contact signal according to whether the contact pad is in contact, and the contact. And a control unit configured to perform a power control operation in response to a signal, wherein the electrical contact sensor comprises: a reference signal generator for generating a reference signal, a first signal generator for delaying the reference signal and generating a first signal; And a contact pad having the contact pad and delaying the reference signal more than the first signal when the contact pad is in contact, and generating the second signal by delaying the reference signal smaller than the first signal when not in contact. A second signal generator and a touch signal generator for receiving the second signal in synchronization with the first signal to generate the contact signal; Characterized by comprising a.

According to a second aspect of the present invention, there is provided a human interface device including a display unit for displaying data on a screen, and a plurality of contact pads arranged in a predetermined pattern, and a contact object contacts the plurality of contacts. An electrical scroll device that generates at least one or more touch signals upon contact with at least one of the pads, and analyzes the touch signals to determine the location of the contact pads that the contact object contacts, And a control unit for scrolling the screen in a direction corresponding to a position, wherein the electric scroll device includes the contact pad, and a plurality of electrical contacts respectively generating the contact signal as the contact object contacts the contact pad. And sensors.

Hereinafter, referring to the accompanying drawings, an electrical contact sensor and a human interface device using the same will be described.

3 is a block diagram of an electrical contact sensor in accordance with the teachings of the present invention.

As shown in the figure, the electrical contact sensor of the present invention, the reference signal generator 10, the first signal generator 21, the second signal generator 22, the contact signal generator 30 And a filter unit 40.

Looking at the function of each component as follows.

The reference signal generator 10 generates an alternating current (AC) signal or a clock signal as a reference signal ref_sig and applies them to the first signal generator 21 and the second signal generator 22, respectively.

The first signal generator 21 generates the first signal sig1 by always delaying the reference signal ref_sig for a first time regardless of whether or not the contact object is in contact.

The second signal generator 22 includes a contact pad PAD to which a contact object contacts, and if the contact object does not contact the contact pad PAD, the second signal generator 22 does not delay the reference signal ref_sig and does not delay the contact pad PAD. When the contact object is in contact with, the reference signal ref_sig is delayed more than the first time to generate the second signal sig2.

That is, the second signal generator 22 generates a second signal sig2 having a phase faster than that of the first signal sig1 when the contact object is not in contact, and when contacting the second signal generator 22. Generate a second signal sig2 having a phase slower than the phase.

In the present invention, any object having a predetermined capacitance may be applied to the contact object, and a representative example is a human body capable of accumulating a large amount of electric charge.

The touch signal generator 30 generates a contact signal con_sig by sampling and latching the second signal sig2 in synchronization with the first signal sig1.

The filter unit 40 receives the contact signal con_sig and removes various noise signals generated when the contact object of the contact signal generator 30 contacts the contact pad or when the contact object is unstablely touched. And stabilization and smoothing to generate an output signal out_sig.

4 is a circuit diagram according to an embodiment of the electrical contact sensor of FIG. 3. Referring to the drawings, the first signal generator 21 is positioned between the reference signal generator 10 and the contact signal generator 30. And a capacitor CAP positioned between the first resistor R11, the first resistor R11, and the contact signal generator 30, and connected to the ground voltage VSS. 22 is positioned between the second resistor R12 and the second resistor R12 and the contact signal generator 30 positioned between the reference signal generator 10 and the contact signal generator 30 to perform a power failure. And a contact pad (PAD) that allows a contact object having a capacity to be contacted.

In this case, the first and second resistors R11 and R12 are resistors such that the delay component between the reference signal generator 10 and the capacitor CAP and the delay component between the reference signal generator 10 and the contact pad PAD are the same. As a result, it has a very slight delay component.

At this time, the capacitor CAP has a capacitance smaller than that of the contact object. That is, to have a smaller capacitance than the average human body has a capacitance.

The contact signal generator 30 is implemented as a D-flipflop, and the filter unit 40 is implemented as a low pass filter.

Hereinafter, the operation of the electrical contact sensor of FIG. 4 will be described with reference to FIG. 5.

5A is an operation circuit diagram of the electrical contact sensor 40 when the contact object is not in contact. FIG. 5B is a signal waveform diagram of the electrical contact sensor 40 of FIG. 5A. FIG. 5C is an electrical contact sensor when the contact object is in contact. 40 is an operation circuit diagram, and FIG. 5D is a signal waveform diagram of the electrical contact sensor 40 of FIG. 5C.

First, an operation of the electrical contact sensor 40 performed at the time of non-contact of a contact object will be described with reference to FIGS. 5A and 5B.

Referring to FIG. 5A, the delay component of the first signal generator 21 becomes the first resistor R11 and the first capacitor CAP1 when the contact object is not in contact, and delays the second signal generator 22. The component becomes the second resistor R12.

Here, the first resistor R11, the second resistor R12, and the first capacitor CAP1 have the same value as the first resistor R11, the second resistor R12, and the capacitor CAP1 of FIG. 4. Have In this case, since the first and second resistors R11 and R12 have very small delay components, the delay times according to the first and second resistors R11 and R12 will be ignored.

As shown in FIG. 5B, the first signal generator 21 delays the first signal sig1 by delaying the reference signal ref_sig by the first time according to the first capacitor CAP1, and then the second signal generator. Reference numeral 22 generates a second signal sig2 having the same phase as the reference signal ref_sig, respectively.

That is, the phase of the second signal sig2 is faster than the phase of the first signal sig1, so that the rising edge or the falling edge of the second signal sig2 occurs, and the first signal sig1 must pass after a first time elapses. Rising edge or falling edge of occurs.

Then, the flip-flop 30 acquires the low level of the second signal sig2 in synchronization with the falling edge of the first signal sig1, generates the contact signal con_sig having the low level, and generates the low pass filter ( 40 may filter the contact signal con_sig to generate an output signal out_sig having a low level.

Next, the operation of the electrical contact sensor 40 performed at the time of contact of the contact object will be described with reference to FIGS. 5C and 5D.

5C, the delay component of the first signal generator 21 is the same as that of FIG. 5A when the contact object is in contact, but the delay component of the second signal generator 22 is the capacitance CAP2 of the contact object. You can see that it increases by).

As shown in FIG. 5D, the first signal generator 21 generates the second signal from the first signal sig1 obtained by delaying the reference signal ref_sig by the first time according to the first capacitor CAP1. The unit 22 generates the second signal sig2 which is further delayed by the first time according to the capacitance CAP2 of the contact object.

That is, the phase of the first signal sig1 is faster than the phase of the second signal sig2, so that the rising edge or falling edge of the first signal sig1 is generated first, and the rising edge or falling edge of the second signal sig2 is generated. Edges are generated later.

Then, the flip-flop 30 acquires the high level of the second signal sig2 in synchronization with the falling edge of the first signal sig1, generates the contact signal con_sig having the high level, and generates the low pass filter ( 40 filters the contact signal con_sig to generate an output signal out_sig having a high level.

As described above, the electrical contact sensor of the present invention uses the principle that the contact object has capacitance and the phase of the contact signal is changed according to the capacitance of the contact object. Allow electrical detection.

Therefore, even if the contact object is a non-conductive insulator, if the object has a predetermined amount or more of capacitance, the contact object can be electrically detected.

In addition, although the contact signal generator 30 of FIG. 4 is limited to the flip-flop 30 operated in synchronization with the falling edge of the first signal sig1, the rising edge of the first signal or Naturally, the same effect can be provided even when the operation is performed in synchronization with the rising edge of the second signal sig2. In addition to the flip-flop, the contact signal generator 30 may also be implemented using a JK flip-flop and a latch circuit that can acquire and latch the contact signal in synchronization with the first signal.

In addition, although the filter unit 30 of FIG. 4 is limited to a low pass filter, the filter unit 30 of FIG. 4 may also be implemented through various filters that may perform the same function as the low pass filter.

6 and 8A illustrate embodiments of a mouse using the electrical contact sensor of FIG. 3, wherein the mouse of FIG. 6 is a mouse performing power control using the touch sensor, and the mouse of FIG. A mouse that scrolls using a touch sensor.

First, referring to FIG. 6, the mouse 60 is connected to a contact pad (PAD) installed on an upper surface of the mouse, and connected to an electrical contact sensor 61 and a contact pad (PAD) for detecting and notifying a contact of a contact object. Microcontrol unit 62 (MCU) activating the operation of the mouse and the power supply unit 64 only when the contact object is notified that the object is contacted, and an image for calculating the motion value of the mouse by image processing the image of the acquired object. A sensor 63, a power supply unit 64 for generating operating power of a mouse, a wireless communication interface unit 65 for interfacing data between the MCU 62 and a computer, a key button 66, and a scroll device ( 67).

The user must touch the hand to the upper surface of the mouse 60 to use the mouse 90.

Accordingly, when the MCU 62 of FIG. 6 detects that a human hand is not in contact with the upper surface of the mouse through the electrical contact sensor 61 as in the sections 2 and 4 of FIG. 7, the power supply unit The operation of 64 is deactivated, and the operation power to each component 63, 65, 66, 67 is cut off to deactivate the operation of the mouse.

On the other hand, when the MCU 62 detects that a human hand is in contact with the upper surface of the mouse, such as the sections 1 and 3 of FIG. 7, the MCU 62 operates the power supply 64. By activating, the operation power is supplied to each of the components 63, 65, 66, and 67 to activate the operation of the mouse.

Accordingly, the mouse of FIG. 6 activates the operation of the mouse only when a person comes into contact with the upper surface of the mouse to use the mouse, and transmits the motion value calculated through the image sensor 63 through the wireless communication interface 65. Provide it to your computer.

If the mouse 60 of FIG. 6 is a wireless mouse, the use of a rechargeable battery or a battery as a power source is restricted by the use time, so it is important to extend the use time to the maximum.

Therefore, the mouse 60 of the present invention activates the operation of the mouse 60 by providing operation power to each component only when a person comes into contact with the mouse 60 as described above, thereby wasting power source. And thus, the use time of the wireless mouse 60 can be significantly increased.

In the above, the mouse is limited to a device using an electrical contact sensor. However, all kinds of human interface devices that need to be operated only when a person comes into contact with each other to reduce power consumption can adopt the above method. .

8A, the mouse 70 includes an image sensor 63, a power supply 64, a wireless communication interface 65, and a key button 66 as in FIG. 6. The scroll device 67 and the MCU 62 of 6 are replaced by the plurality of electrical contact sensors 71 and the MCU 72.

The plurality of electrical contact sensors 71 have a predetermined pattern as shown in FIG. 8B and are connected to a plurality of contact pads PADS disposed on the upper surface of the mouse, thereby implementing an electrical scroll device. At this time, each of the electrical contact sensors 71 detects and notifies the contact of the contact object to the contact pad PAD as shown in the electrical contact sensor 61 of FIG. 6.

The MCU 72 determines the scroll direction by combining signals transmitted from the plurality of electrical contact sensors 71, and generates scroll data for scrolling the display screen of the computer in the corresponding direction and transmits the scroll data to the computer.

Accordingly, the mouse of FIG. 8A detects the contact position of the user through the plurality of electrical contact sensors 71 and the scroll direction corresponding to the contact position of the user through the MCU 72, thereby requiring the user. Generates scrolling data that causes the computer's display screen to scroll.

For example, when the user contacts only some of the contact pads P5 and P6 disposed below the plurality of contact pads PADS arranged up and down as shown in FIG. 8B, the partial contact pads P5 and P6 are disposed. Only some contact sensors corresponding to) generate an output signal having a high level. The MCU 72 detects that some of the contact pads P5 and P6 disposed below the plurality of contact pads P1 to P6 are in contact and generates scroll data for scrolling the display screen downward.

The mouse device of FIG. 8A can reduce the space occupied by the conventional mechanical scroll device, thereby enabling the implementation of a very thin mouse device and increasing the durability of the device by eliminating the highly wearable mechanical device.

In addition, as shown in FIGS. 9A and 9B, the plurality of electrical contact sensors of FIG. 3 arrange contact pads PADS connected to each electrical contact sensor in a predetermined pattern on a character arrangement board of a mobile terminal or an MP3 player. It can also be used as a scrolling device, a location tracking device, or a location input device.

That is, when the user moves a finger on the contact pads arranged in a predetermined pattern, the touch pad may be used as a position input device that displays the movement on the display screen or selects a specific item displayed on the display screen.

As described above, the electrical contact sensor of the present invention includes only one contact pad, and its configuration is simple, so that it can be easily applied to any device that utilizes the presence or absence of a contact or a change in contact position.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand that you can.

Therefore, the electrical contact sensor of the present invention provides a reliability of operation by allowing the contact object to accurately determine the presence or absence of contact, even if the conductivity is not sufficient, even if the contact object has a predetermined charge accumulation capability. This makes it possible to operate the electrical contact sensor stably regardless of the humidity of the weather and the presence or absence of a conductive gap between people or wearing a glove.

In addition, the electrical contact sensor can reduce the layout of the product by determining whether the contact object is in contact with only one contact pad.

In addition, the human interface device of the present invention can provide more improved and various functions, such as controlling a power supply or scrolling using an electrical contact sensor.

Claims (14)

A reference signal generator for generating a reference signal; A first signal generator having a first resistor and a first capacitor and generating a first signal by delaying the reference signal through the first resistor and the first capacitor; A second resistor and one contact pad, and when the contact object is in contact, delays the reference signal more than the first signal through the second resistor and the contact pad, and in case of non-contact, the second signal. A second signal generator configured to generate a second signal by delaying the first signal less than the first signal according to a resistance; And And a contact signal generation unit configured to receive the second signal in synchronization with the first signal or to generate the contact signal by receiving the first signal in synchronization with the second signal. The method of claim 1, The first resistor is connected between the reference signal generator and the contact signal generator, The capacitor is connected between the first resistor and a ground voltage. The method of claim 2, And the capacitor has a smaller capacitance than the contact object. The method of claim 1, The second resistor is connected between the reference signal generator and the contact signal generator, The contact pad is connected between the second resistor and a ground voltage. The method of claim 1, wherein the contact signal generation unit And a flip-flop generating the contact signal by acquiring and latching the second signal in synchronization with the first signal. The method of claim 1, wherein the contact signal generation unit And a flip-flop generating the contact signal by acquiring and latching the first signal in synchronization with the second signal. The method of claim 1, wherein the contact signal generation unit And a latch circuit for latching the contact signal in synchronization with the first signal to generate the second signal. The method of claim 1, wherein the contact signal generation unit And a latch circuit for latching the first signal in synchronization with the second signal to generate the contact signal. The method of claim 1, wherein the electrical contact sensor Electrical contact sensor, characterized in that further comprising a filter for outputting after stabilizing and smoothing the contact signal. At least one electrical contact sensor having contact pads, each generating a contact signal according to whether the contact pads are in contact; And A control unit configured to perform a power control operation in response to the contact signal, The electrical contact sensor is A reference signal generator for generating a reference signal; A first signal generator having a first resistor and a first capacitor and generating a first signal by delaying the reference signal through the first resistor and the first capacitor; A second resistor and one contact pad, and when the contact object is in contact, delays the reference signal more than the first signal through the second resistor and the contact pad, and in case of non-contact, the second signal. A second signal generator configured to generate a second signal by delaying the first signal less than the first signal according to a resistance; And And a contact signal generator configured to receive the second signal in synchronization with the first signal or to receive the first signal in synchronization with the second signal to generate the contact signal. A display unit displaying data on a screen; An electrical scroll device having a plurality of contact pads arranged in a predetermined pattern and generating at least one or more contact signals as a contact object contacts at least one or more of the plurality of contact pads; And A control unit for analyzing the contact signals to determine the positions of the contact pads in contact with the contact object, and scrolling the screen in a direction corresponding to the positions of the contact pads, The electrical scroll device A first signal generation unit including a reference signal generator for generating a reference signal, a first resistor and a first capacitor, and generating a first signal by delaying the reference signal through the first resistor and the first capacitor; And a second resistor and one contact pad, wherein the reference signal is delayed more than the first signal through the second resistor and the contact pad when the contact object is in contact, and when the contact object is not in contact, A second signal generator for generating a second signal by delaying the first signal less than the first signal, and receiving the second signal in synchronization with the first signal or in synchronization with the second signal; And a plurality of electrical contact sensors each having a contact signal generator for receiving one signal and generating the contact signal. delete The method of claim 11, wherein the control unit And a function of displaying position information of the contact pads in contact with the contact object on the screen. The method of claim 11, wherein the control unit And a function of selecting the item displayed on the screen by analyzing the contact signals.

Images