JP2013174585A - Human body detection device and key confinement release device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a human body detector which is highly resistant to external noise.SOLUTION: A human body detector 1 includes; an electrode 10 located at a distance from another electrode 40; oscillators 20, 40 which feed two square wave signals of opposite phase to the electrode 10 and the other electrode 40, respectively; and a microcomputer 70 which detects a human body in the vicinity of the electrode 10 and the other electrode 40 on the basis of changes in the voltage waveform fed to each electrode.

Description

  The present invention relates to a human body detection device that detects the proximity of a human body and a key confinement release device including the human body detection device.

  As a sensor for detecting the approach of the human body, for example, in Patent Document 1, as shown in FIG. 8, it is determined whether or not the capacitance change generated near the sensor electrode is caused by the human body, and the human body approaches. What detects this is described. The human body detection apparatus 100 sequentially applies low-frequency and high-frequency alternating voltages to one sensor electrode 101, detects changes in the capacitance of the sensor electrode 101 as voltage variations at each frequency, and detects the human body or It is detecting raindrops.

JP 2006-2111427 A

  However, since the above-described human body detection device is in a state where the sensor electrode floats from the ground surface, there is a problem that the amount of change in the signal detected by the sensor electrode is small and it is weak against external noise such as rain.

  Accordingly, the present invention is intended to provide a human body detection device capable of solving the above-described problems of the prior art and a key confinement release device including the human body detection device.

In order to solve the above problems, the human body detection device of the present invention is
One electrode and the other electrode which are spaced apart,
An oscillator for applying a periodically varying voltage waveform to the one electrode and the other electrode;
A microcomputer for detecting that the human body is close to the one electrode and the other electrode based on the change in the voltage waveform,
The voltage waveforms applied to the one electrode and the other electrode have different phases or periods.

The human body detection device according to claim 2 of the present invention is the human body detection device according to claim 1,
A first resistor is provided between the oscillator and the one electrode,
A second resistor is provided between the oscillator and the other electrode,
The microcomputer detects a change in the voltage waveform between the one electrode and the first resistor and between the other electrode and the second resistor.

The human body detection device according to claim 3 of the present invention is the human body detection device according to claim 1,
The distance between the one electrode and the other electrode is 30 mm or more and 2 m or less.

According to a fourth aspect of the present invention, there is provided a key confinement releasing device comprising the human body detecting device according to any one of the first to third aspects and a judging means, wherein the door is locked with the key left in the room. A key confinement release device for releasing the door lock from
Inside the glass inside the room, the one electrode and the other electrode are pasted at a position where they can be seen from the outside,
The human body detection device detects a signal of a door lock release request operation in a key confined state by repeating proximity and separation of the human body from the outside to the one electrode and the other electrode,
The determination means compares the cancellation request operation signal with a regular key signal preset and registered by a regular user,
The door lock is unlocked if the comparison result of the determination means is the same, and the door lock is not unlocked if the comparison result of the determination means is not the same.

  According to the human body detection device of the present invention, when the human body is close to both the one electrode and the other electrode, a closed loop state is formed by the action of the capacitor using the human body as a medium. Since the periodically varying voltage waveforms applied to one electrode and the other electrode are different in phase or period, a signal (change in electric field) is passed between the two electrodes via the human body according to the potential difference. Accompanying signal) is transmitted, and both voltage waveforms applied to one electrode and the other electrode change. For this reason, it is possible to detect that the human body has approached both the one electrode and the other electrode by detecting changes in these voltage waveforms. In addition, since a change in the voltage waveform can be detected in a closed loop state via a human body, a human body detection device that is hardly affected by outside and is resistant to external noise can be obtained.

1 is a block diagram of a human body detection device according to a first exemplary embodiment of the present invention. They are a waveform detection unit (a) and a comparator (b) according to the first embodiment of the present invention. In the first embodiment of the present invention, there are a waveform (a) at the measurement point C and a waveform (b) at the measurement point D in FIG. 1 in a state where the human body is not close to the two electrodes. They are a waveform (c) at the measurement point C and a waveform (d) at the measurement point D in FIG. FIG. 3 is a modification of the voltage waveform in the first embodiment of the present invention, and shows a waveform (a) at a measurement point C and a waveform (b) at a measurement point D in FIG. These are the waveform (c) at the measurement point C and the waveform (d) at the measurement point D in FIG. 1 in a state where the human body is close to the two electrodes. FIG. 3 is a modification of the voltage waveform in the first embodiment of the present invention, and shows a waveform (a) at a measurement point C and a waveform (b) at a measurement point D in FIG. They are the waveform (c) at the measurement point C and the waveform (d) at the measurement point D in FIG. 1 in a state where the human body is close to the two electrodes. FIG. 3 is a modification of the voltage waveform in the first embodiment of the present invention, and shows a waveform (a) at a measurement point C and a waveform (b) at a measurement point D in FIG. They are the waveform (c) at the measurement point C and the waveform (d) at the measurement point D in FIG. 1 in a state where the human body is close to the two electrodes. It is a figure which shows the state which mounted | wore the vehicle with the key confinement cancellation | release apparatus provided with the human body detection apparatus of this invention. It is a figure explaining a prior art.

  Hereinafter, embodiments of the present invention will be exemplarily described based on the drawings.

(First embodiment)
A human body detection apparatus according to a first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, 10 is one electrode, 20 is one oscillator, 30 is a first waveform detector, 40 is the other electrode, 50 is the other oscillator, 60 is a second waveform detector, and 70 is a microcomputer. .

One electrode 10 and the other electrode 40 are sensor electrodes that detect the proximity of a human body. As shown in FIG. 1, the electrodes 10 and 40 of this example are formed by sticking rectangular spiral copper wires 10A and 40A to transparent insulating films 10B and 40B having adhesiveness on one side. One ends of the copper wires 10A and 40A are connected to one oscillator 20 and the other oscillator 50, respectively, and the other ends of the copper wires 10A and 40A are open ends. The electrodes 10 and 40 may be formed by forming a spiral coil pattern on a flexible substrate, may be a square electrode made of a conductive solid pattern on a flexible substrate, or may be an antenna.
The electrodes 10 and 40 of this example are arranged in parallel in the same plane and are spaced apart. Note that the arrangement of the two electrodes is not particularly limited as long as one electrode 10 and the other electrode 40 are at least separated by a predetermined distance L described later. This distance L indicates the shortest distance between the electrodes.

One oscillator 20 and the other oscillator 50 apply voltage waveforms (rectangular waves in this example) that vary periodically in phase to one electrode 10 and the other electrode 40, respectively. This rectangular wave is 5 Vp-p as shown in FIG. 3A, and is the same as the operating voltage of the microcomputer 70 described later.
The frequency of this rectangular wave is 20 MHz in this example, and is preferably 1 MHz to 40 MHz. This frequency is a band in which signal transmission by capacitive coupling through the human body is easy.

A first buffer (buffer amplifier) 21 and a first resistor 22 are connected between one oscillator 20 and one electrode 10.
A second buffer 41 (buffer amplifier) and a second resistor 42 are connected between the other oscillator 50 and the other electrode 40.
The first resistor 22 and the second resistor 42 are, for example, 10 kΩ, and function as voltage dividing resistors when detecting a change in the voltage waveform when a human body approaches the one electrode 10 and the other electrode 40.

The first waveform detection unit 30 includes a first rectifier circuit 31 and a first comparator 32. The second waveform detection unit 60 includes a second rectifier circuit 61 and a second comparator 62.
The first rectifier circuit 31 and the second rectifier circuit 61 are rectifier circuits having diodes 31A and 61A and smoothing capacitors 31B and 61B, respectively (see FIG. 2).
The first rectifier circuit 31 converts a voltage waveform appearing between one electrode 10 and the first resistor 22 (measurement point C in FIG. 1) into a direct current, and outputs a first maximum voltage value. The second rectifier circuit 61 converts a voltage waveform appearing between the other electrode 40 and the second resistor 42 (measurement point D in FIG. 1) into a direct current, and outputs a second maximum voltage value.
The first comparator 32 outputs a result of comparing the first maximum voltage value and the first reference voltage value Vref1, and the second comparator 62 compares the second maximum voltage value and the second reference voltage value Vref2. The result is output. The first reference voltage value Vref1 and the second reference voltage value Vref2 are both set to 0.1 V in this example.

The first comparator 32 outputs a high level (5 V in this example) when the first maximum voltage value is lower than the first reference voltage value Vref1, and the low level when the first maximum voltage value is higher than the first reference voltage value Vref1. (0V in this example) is output.
The second comparator 62 outputs a high level (5 V in this example) when the second maximum voltage value is lower than the second reference voltage value Vref2, and when the second maximum voltage value is higher than the second reference voltage value Vref2. A low level (0 V in this example) is output.

  The microcomputer 70 detects that the human body is close to the one electrode 10 and the other electrode 40, and operates at 5V which is generally used. The microcomputer 70 receives the outputs of the first comparator 32 and the second comparator 62.

  Next, the operation of the human body detection device 1 of this example will be described with reference to FIG.

First, the two oscillators 20 and 50 apply voltage waveforms (rectangular waves) having opposite phases to one electrode 10 and the other electrode 40. The voltage waveform in the normal state where the human body is not close to the two electrodes is as shown in FIGS. 3 (a) and 3 (b). 3A shows the waveform at the measurement point C in FIG. 1, and FIG. 3B shows the waveform at the measurement point D in FIG.
In this case, the first rectifier circuit 31 shapes the voltage waveform at the measurement point C and outputs a first maximum voltage value (5 V in this example), and the first comparator 32 outputs a low level.
The second rectifier circuit 32 shapes the voltage waveform at the measurement point D and outputs the second maximum voltage value (5 V in this example), and the second comparator 62 outputs a low level.
The microcomputer 70 detects that the human body is not in proximity to the two electrodes by detecting that both the outputs of the first comparator 32 and the second comparator 62 are at a low level.

Next, a state where the human body is close to the two electrodes will be described. This close state may be, for example, a state in which both hands are close to one electrode and the other electrode, or a state in which one hand is close across two electrodes.
The oscillators 20 and 50 apply voltage waveforms having opposite phases to one electrode 10 and the other electrode 40. Therefore, when the human body approaches the two electrodes 10 and 40, a closed loop state is formed by the action of the capacitor using the human body as a medium. Since the voltage waveforms applied to one electrode 10 and the other electrode 40 are in opposite phases, a signal (signal accompanying a change in electric field) is passed between the two electrodes via the human body according to the potential difference. The voltage waveform transmitted and applied to one electrode 10 and the other electrode 40 changes.
The voltage waveforms when the human body is close to the two electrodes are as shown in FIGS. FIG. 3C shows a waveform at the measurement point C in FIG. 1, and FIG. 3D shows a waveform at the measurement point D.

In the period T1 in FIG. 3, a high frequency signal is transmitted from the high potential side electrode 10 to the low potential side electrode 40 through the human body, and the potential at the measurement point C decreases as shown in FIG. In this example, it becomes 0.05 V), and the potential at the measurement point D remains almost 0 V as shown in FIG.
Further, in the period T2 in FIG. 3, a high frequency signal is transmitted from the high potential side electrode 40 to the low potential side electrode 10 through the human body, and the potential at the measurement point D decreases as shown in FIG. However, in this example, it becomes 0.05V, and the potential at the measurement point C remains almost 0V as shown in FIG.
Also in each period of T3, T4, T5,... In FIG. 3, a high-frequency signal is transmitted from the high-potential side electrode to the low-potential side electrode via the human body, and the potentials at the measurement points C and D alternate. To drop.
For this reason, when the human body approaches the two electrodes, the maximum voltage values at the measurement points C and D both decrease.

The first rectifier circuit 31 shapes the voltage waveform at the measurement point C and outputs a first maximum voltage value (0.05 V in this example), and the first comparator 32 outputs a high level.
The second rectifier circuit 61 shapes the voltage waveform at the measurement point D and outputs a second maximum voltage value (0.05 V in this example), and the second comparator 62 outputs a high level.

Then, the microcomputer detects that both the outputs of the first comparator 32 and the second comparator 62 are at a high level, and detects that the human body is in a state of being close to the two electrodes.
Therefore, when a decrease in the maximum voltage value applied to the two electrodes 10 and 40 is detected, the microcomputer 70 can detect that the human body has approached the two electrodes 10 and 40.

  As described above, the human body detection device 1 of the present example has one electrode 10 and the other electrode 40 that are separated from each other, and a voltage waveform that periodically fluctuates between the one electrode 10 and the other electrode 40 (in this example, (Rectangular waves) 20 and 50, respectively, and a microcomputer 70 that detects that the human body is close to one electrode 10 and the other electrode 40 based on the change in the voltage waveform. In this example, the voltage waveforms applied to one electrode 10 and the other electrode 40 are in opposite phases.

According to the human body detection device 1 of this example, when the human body is close to both the one electrode and the other electrode, a closed loop state is formed by the action of the capacitor using the human body as a medium. Since the two voltage waveforms applied to one electrode and the other electrode are in opposite phase to each other, a signal (signal accompanying a change in the electric field) is passed between the two electrodes via the human body according to the potential difference. And the maximum voltage value applied to one electrode and the other electrode decreases. For this reason, it is possible to detect that the human body has approached both the one electrode and the other electrode by detecting the change in the maximum voltage value.
In addition, since a change in the voltage waveform can be detected in a closed loop state via a human body, a human body detection device that is hardly affected by outside and is resistant to external noise can be obtained.
Moreover, since the extremely stable voltage waveform is detected when the human body is close to the two electrodes, the human body detection apparatus of this example can increase the detection sensitivity and improve the reliability when the human body is close to the two electrodes.

When the voltage waveform applied to one electrode is detected on the other electrode side, the voltage waveform changes between when the human body is close to the two electrodes and when the human body is not close. Is very small and high detection accuracy cannot be obtained.
On the other hand, in the human body detection device of this example, a first resistor 22 is provided between one oscillator 20 and one electrode 10, and a second resistor is provided between the other oscillator 50 and the other electrode 40. A resistor 42 is provided, and the microcomputer 70 detects a change in voltage waveform between one electrode 10 and the first resistor 22 and between the other electrode 40 and the second resistor 42. Yes. Therefore, when the human body approaches the two electrodes, changes in the voltage waveform applied to the two electrodes can be directly detected, so that the proximity of the human body can be detected with high accuracy.

  Further, in the human body detection device 1 of this example, since rectangular waves having opposite phases to each other are applied to the one electrode 10 and the other electrode 40, when the human body is close to the two electrodes, FIG. 3C and FIG. As shown in 3 (d), the maximum voltage value is significantly reduced. Therefore, human body detection can be performed easily and with high accuracy by detecting the change in the maximum voltage value.

In the human body detection device 1 of this example, the distance L between the one electrode 10 and the other electrode 40 is preferably 30 mm or more.
That is, the closer the two electrodes are, the more easily the potential on the low potential side is affected by the potential on the high potential side, and the detection accuracy is likely to decrease.
In the case of this example, when the frequency of the rectangular wave is 1 MHz and the distance L = 0 mm, the potential of the other electrode received from one electrode is 0.1 Vp-p, the frequency of the rectangular wave is 40 MHz, and the distance L = 0 mm. In this case, the potential of the other electrode received from one electrode was 0.06 Vp-p.
Therefore, when the minimum distance Lmin that is less than the maximum voltage value (0.05 Vp-p in this example) when the human body is close to the two electrodes is measured, the distance Lmin is 30 mm when the frequency is 1 MHz. When the frequency was 40 MHz, the distance Lmin was 50 mm.
Therefore, when the distance L between the one electrode 10 and the other electrode 40 is at least 30 mm to 50 mm or more and is 5 Vp-p, 1 MHz or more and 40 MHz or less, the human body is close to the two electrodes Is not included in the signal received when the two electrodes are close to each other, and the signal when the human body is close to the two electrodes can be accurately detected.

  Moreover, in the human body detection apparatus of this example, the distance between one electrode 10 and the other electrode 40 is preferably 2 m or less. In this example, since both hands are used in close proximity to one electrode 10 and the other electrode 40, an easy-to-use human body detection device capable of detecting a distance in a state where both hands are spread out is obtained.

  As mentioned above, although one embodiment of the present invention has been described, the present invention is not limited to this embodiment, and appropriate modifications, addition / deletion of parts, and the like can be made without departing from the gist of the present invention. Needless to say, you can.

In the above embodiment example, a rectangular wave is applied to one electrode 10 and the other electrode 40, but the voltage waveform applied to one electrode and the other electrode may be one that periodically fluctuates, A sine wave or a triangular wave may be used.
In the above embodiment, voltage waveforms having opposite phases are applied to one electrode 10 and the other electrode 40. However, they may not be completely opposite phases as long as they have different phases.
For example, as shown in FIG. 4, the voltage waveform applied to the other electrode 40 (see FIG. 4B) is delayed by α ° from the voltage waveform applied to one electrode 10 (see FIG. 4A). May be. In this case, when the human body is close to the two electrodes, a period β in which the voltage is 5 V is detected at the measurement point C and the measurement point D, and it is detected that the period β is smaller than the predetermined period. The proximity of the two electrodes 10 and 40 can be detected.

  For example, as shown in FIG. 5, the voltage waveform applied to one electrode 10 and the voltage waveform applied to the other electrode 40 may have different periods. In the example of FIG. 5, the voltage waveform applied to one electrode 10 (see FIG. 5A) is 5 Vp-p, 20 MHz, and the voltage waveform applied to the other electrode (see FIG. 5B). Is 5 Vp-p, 21 MHz. In this case, when the human body is close to the two electrodes, periods γ1, γ2, γ3,... With a voltage of 5 V are detected at the measurement points C and D, and the minimum values of the periods γ1, γ2, γ3,. Is detected to be smaller than the predetermined period (by detecting γ10 in this example), it can be detected that the human body is close to the two electrodes 10 and 40.

  3 to 5, the voltage waveform of 5 Vp-p is applied to one electrode 10 and the other electrode 40. If the phases or periods are different from each other, for example, the voltage waveform is applied to one electrode. The voltage waveform applied may be 5 Vp-p, and the voltage waveform applied to the other electrode may be 2.5 Vp-p. In this case, when the human body is close to the two electrodes, the amplitude change on the 2.5 Vp-p side is small, and the detection accuracy slightly decreases. Therefore, when the voltage waveform has the same peak-to-peak as in the previous embodiment, detection can be performed with the highest accuracy.

  Further, in the above embodiment example, one oscillator 10 and 50 are applied to one electrode 10 and the other electrode 40, respectively, but a positive phase voltage waveform is applied to one electrode using one oscillator. It is also possible to apply an inverted reversed phase voltage waveform to the other electrode.

  In the above embodiment, a rectangular wave whose one of the two levels is 0V is applied. However, as shown in FIGS. 6A and 6B, alternating waveforms with different phases (this example) Then, rectangular waves having opposite phases to each other may be used. When this AC waveform is applied to one electrode and the other electrode, respectively, when the human body is close to the two electrodes, the amplitudes at the measurement points C and D are as shown in FIGS. 6 (c) and 6 (d). Both are reduced, and the same effect as described above can be obtained. Such a waveform is considered to be because the positive high potential (+5 V) becomes more dominant than the negative high potential (−5 V). Even when such an AC waveform is applied to one electrode and the other electrode, the periods may be different from each other.

(Second Embodiment)
Next, a mounting example of the human body detection device 1 will be described. FIG. 7 shows a key confinement release device 80 including the human body detection device 1. The key confinement releasing device 80 is for unlocking the door lock from the door locked state, for example, leaving a smart key that can be transmitted and received by radio waves in the interior of the vehicle 90.

  In FIG. 7, a key confinement release device 80 is disposed in the room, and one electrode 10 and the other electrode 40 are pasted inside the transparent windshield 91 near the dashboard in the room at a position where they can be seen from the outside. It is attached. The attachment position of these two electrodes is not limited to the windshield, but may be any position where the user (owner of the vehicle) can visually recognize (for example, rear glass).

The key confinement release device 80 includes the human body detection device 1 and a determination unit (not shown).
The human body detection device 1 receives a door lock release request operation signal from outside.
When the door lock release request operation signal detected by the human body detection device 1 is input, the determination means receives the release request operation signal and a normal key signal preset and registered by a normal vehicle user. Are compared.

  The operation of unlocking the door lock from the door locked state with the smart key remaining in the vehicle in the key confinement releasing device 80 having such a configuration will be described.

First, the human body detecting device 1 is in a key confined state by repeatedly separating and approaching one electrode 10 with one hand 10 while the other hand is approaching the one electrode 10 and the other electrode 40 from outside. The door lock release request operation signal at is detected.
The signal of the release request operation is, for example, as a two-tone two-ton ton or the like with a short point (short press) as a ton and a long point (long press) as a toe as in a Morse code signal.

  Then, the determination means compares the door lock release request operation signal with a regular key signal that is set and registered in advance. When the comparison results of the determination means are the same, the key confinement release device 80 recognizes the release request operation signal as a legitimate user and unlocks the door lock. Further, when the comparison result of the determination means is not the same, the key confinement release device 80 recognizes that the release request operation signal is not an authorized user and does not unlock the door lock.

  According to the key confinement release device 80 configured as described above, by using the human body detection device 1, one hand is placed on one electrode while both hands are brought close to one electrode and the other electrode, respectively. By repeating the separation and the proximity, the human body detection device receives a door lock release request operation signal, and a highly reliable key confinement release device is obtained.

  In addition, although this embodiment example has been described as a key confinement release device that releases the door lock from the door locked state with the key remaining in the vehicle interior, the door is locked with the key left in the house. It can also be applied as a key confinement release device that releases the door lock from the state. In this case, the key confinement releasing device is arranged in the house, and two electrodes are attached to the inside of the window glass near the door which can be visually recognized by the user.

DESCRIPTION OF SYMBOLS 1 Human body detection apparatus 10 One electrode 10A Copper wire 10B Insulating film 20 One oscillator 21 1st buffer 22 1st resistance 30 1st waveform detection part 31 1st rectifier circuit 31A Diode 31B Smoothing capacitor 32 1st comparator 40 The other electrode 40A Copper wire 40B Insulating film 41 Second buffer 42 Second resistor 50 Other oscillator 60 Second waveform detector 61 Second rectifier circuit 61A Diode 61B Smoothing capacitor 62 Second comparator 70 Microcomputer 80 Key confinement release device 90 Vehicle 91 Front Glass

Claims (4)

One electrode and the other electrode which are spaced apart,
An oscillator for applying a periodically varying voltage waveform to the one electrode and the other electrode;
A microcomputer for detecting that the human body is close to the one electrode and the other electrode based on the change in the voltage waveform,
The human body detection device, wherein the voltage waveforms applied to the one electrode and the other electrode have different phases or periods. A first resistor is provided between the oscillator and the one electrode,
A second resistor is provided between the oscillator and the other electrode,
2. The microcomputer according to claim 1, wherein the microcomputer detects a change in the voltage waveform between the one electrode and the first resistor and between the other electrode and the second resistor. Human body detection device.   The human body detection device according to claim 1, wherein a distance between the one electrode and the other electrode is 30 mm or more and 2 m or less. A key confinement releasing device comprising: the human body detecting device according to any one of claims 1 to 3; and a determining unit, wherein the door lock is released from a door locked state with a key remaining in the room. ,
Inside the glass inside the room, the one electrode and the other electrode are pasted at a position where they can be seen from the outside,
The human body detection device detects a signal of a door lock release request operation in a key confined state by repeating proximity and separation of the human body from the outside to the one electrode and the other electrode,
The determination means compares the cancellation request operation signal with a regular key signal preset and registered by a regular user,
The key lock release device according to claim 1, wherein the door lock is unlocked when the comparison result of the determination means is the same, and the door lock is not unlocked unless the comparison result of the determination means is the same.

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