JP2009133777A - Capacitance type contact detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitance type contact detector which can prevent such the incorrect detection representing that a door handle comes into contact with a user, when rainwater accumulates on a border portion between a door panel and the upper surface of the door handle in a vehicle having a keyless entry system. <P>SOLUTION: The capacitance type contact detector which detects the event that the surface of the door handle on the outer side of the vehicle comes into contact with the user, is equipped with: a capacitance sensor made up of a sensor electrode which is disposed on the door handle and forms a capacitor along with a conductor arranged near the sensor electrode; and a detecting section which detects the event that the surface of the door handle comes into contact with the user, based on a change in the capacitance of the capacitance sensor. In the sensor electrode of the capacitance sensor, the contact detection sensitivity of a part close to the door panel is lower than that of a part far from the door panel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a capacitance-type contact detection device, and more specifically, in a vehicle equipped with a keyless entry system, it is erroneously assumed that a user has touched the door handle when rainwater has accumulated on the boundary between the door handle upper surface and the door panel. The present invention relates to a capacitance type contact detection device that can prevent detection.

Hereinafter, a conventional door handle in a vehicle equipped with a keyless entry system will be described with reference to the drawings.
FIG. 11 is a perspective view showing a conventional door handle.

  In recent years, automobiles are often equipped with a keyless entry system that can lock and unlock a door of an automobile without a key operation. The keyless entry system includes an authentication unit provided in the vehicle, a portable device possessed by the user, and a capacitive touch sensor that is provided on the door handle 100 outside the vehicle and detects the contact when the user contacts the door handle 100. And a locking part for locking the door and an unlocking part for unlocking the door. In FIG. 11, reference numeral 104 denotes a recess formed on the outer surface of the door panel.

  As shown in FIG. 11, the capacitive touch sensor includes a locking sensor electrode 101, an unlocking sensor electrode 103, and a detection unit (not shown). The detection unit detects that the user has touched the upper surface of the door handle 100 for locking based on the signal from the locking sensor electrode 101. The detection unit detects that the user has touched the back side surface of the grip portion 105 of the door handle 100 for unlocking based on a signal from the unlocking sensor electrode 103. The locking sensor electrode 101 is built in the upper part of the door handle 100. Further, the unlocking sensor electrode 103 is incorporated in the back side portion of the grip portion 105 of the door handle 100.

  The operation of this system will be described. First, the operation at the time of unlocking will be described with reference to FIG. When the user holding the portable device approaches the vehicle, the authentication unit communicates with the portable device to authenticate the user. When the authentication unit authenticates the user as a legitimate user and the detection unit detects that the user has gripped the grip 105 of the door handle 100 and touched the back side surface, the unlocking unit unlocks the door. I do.

  Next, the operation at the time of locking will be described. When the user who owns the portable device goes out of the vehicle, the authentication unit communicates with the portable device to authenticate the user. When the authentication unit authenticates the user as a valid user, and the detection unit detects that the user has touched the upper surface of the door handle 100 after the user closed the door, the locking unit locks the door.

  As described above, in the keyless entry system, even when the user does not operate the key, the user unlocks and locks the door only by touching the door handle 100, so that the door can be easily unlocked and locked.

  However, the above keyless entry system has the following problems. That is, when it rains, rainwater may accumulate on the boundary between the upper surface of the door handle 100 and the door panel. When rainwater collects at the boundary between the upper surface of the door handle 100 and the door panel, the rainwater that is a conductor becomes a counterpart electrode of the locking sensor electrode 101 and the electrostatic capacity in the vicinity of the locking sensor electrode 101 increases. In some cases, the user erroneously detected that the user touched the upper surface of the door handle 100. Then, although the user is not in contact with the door handle 100, there is a problem that the door is locked against the user's will.

The door touch sensor described in Patent Document 1 is provided with a locking sensor electrode on the side portion of the door handle, and when this locking sensor electrode is provided on the upper portion of the door handle, it is shown in FIG. The same problem as the case may occur.
JP 2005-139634 A

  The present invention has been made in view of such circumstances, and in a vehicle equipped with a keyless entry system, it is erroneously detected that the user has touched the door handle when rainwater has accumulated on the boundary between the upper surface of the door handle and the door panel. It is an object of the present invention to provide an electrostatic capacitance type contact detection device that can prevent the above.

The capacitive contact detection device according to the present invention is:
A capacitive contact detection device that detects contact when a user contacts the surface of a door handle outside the vehicle,
A capacitance sensor configured by forming a capacitor in cooperation with a conductor near the sensor electrode provided on the door handle;
A detection unit that detects that a user has touched the surface of the door handle based on a change in capacitance in the capacitance sensor;
The capacitance sensor is characterized in that a contact detection sensitivity in a portion near the door panel of the sensor electrode is lower than a contact detection sensitivity in a portion far from the door panel of the sensor electrode.

According to the present invention, in the capacitive sensor, the contact detection sensitivity in the portion near the door panel of the sensor electrode is lower than the contact detection sensitivity in the portion far from the door panel of the sensor electrode. Rainwater tends to accumulate at the boundary between the upper surface of the door handle and the door panel. Accordingly, the present invention reduces the contact detection sensitivity in the portion close to the door panel, thereby preventing the user from erroneously detecting that the user has touched the door handle when rainwater collects on the boundary between the upper surface of the door handle and the door panel. can do.
Further, according to the present invention, the contact detection sensitivity at a portion far from the door panel of the sensor electrode remains high, so that when the user touches the door handle, the contact can be detected with high sensitivity. Note that the portion of the sensor electrode far from the door panel is at a position corresponding to the portion where the user can easily touch the door handle.

In the present invention,
It is preferable that the sensor electrode has a notch formed in a portion close to the door panel.

When rainwater, which is a conductor, adheres to the boundary between the door handle and the door panel, the rainwater becomes the counterpart electrode of the sensor electrode. When a notch is formed in a portion of the sensor electrode near the door panel, the sensor electrode has a smaller area facing the counterpart electrode (that is, rainwater) in the portion near the door panel. Therefore, in the portion close to the door panel, the area S in the capacitance formula: C = ε · (S / d) is reduced, and the capacitance change ΔC is also reduced. Thereby, the contact detection sensitivity of an electrostatic capacitance sensor falls in the part near a door panel. Therefore, the present invention can prevent erroneous detection that the user has touched the door handle when rainwater has accumulated on the boundary between the upper surface of the door handle and the door panel.
Although the number of notches is not particularly limited, it is preferable that a plurality of notches are uniformly formed in a portion near the sensor electrode door panel. Moreover, the shape of the notch is not particularly limited, and for example, a slit shape, a round through hole, or a square through hole can be used. When a plurality of slits are formed in parallel to each other, a portion close to the door panel has a comb shape.

In the present invention,
The sensor electrode is housed in a housing of the door handle,
It is preferable that the thickness of the case near the sensor panel is larger in the vicinity of the sensor electrode than the thickness of the part far from the door panel.

  When rainwater, which is a conductor, adheres to the boundary between the upper surface of the door handle and the door panel, the rainwater becomes the counterpart electrode of the sensor electrode. When the thickness of the portion near the door panel of the housing is larger than the thickness of the portion far from the door panel of the housing, the distance between the portion of the sensor electrode near the door panel and the counterpart electrode (ie, rainwater) is from the sensor electrode door panel. The distance is larger than the distance between the far portion and the counterpart electrode (that is, rainwater). Therefore, in the portion of the sensor electrode close to the door panel, the distance d in the capacitance equation: C = ε · (S / d) increases, and the capacitance change ΔC decreases. Thereby, the contact detection sensitivity of an electrostatic capacitance sensor falls in the part near a door panel. Therefore, the present invention can prevent erroneous detection that the user has touched the door handle when rainwater has accumulated on the boundary between the upper surface of the door handle and the door panel.

In the present invention,
The sensor electrode is housed in a housing of the door handle,
In the casing, it is preferable that a dielectric constant of a portion near the door panel is smaller than a dielectric constant of a portion far from the door panel in the vicinity of the sensor electrode.

  When rainwater, which is a conductor, adheres to the boundary between the upper surface of the door handle and the door panel, the rainwater becomes the counterpart electrode of the sensor electrode. When the dielectric constant of the portion near the door panel of the housing is smaller than the dielectric constant of the portion far from the door panel of the housing, the capacitance formula: C = ε · (S / d) in the portion near the door panel of the housing. ) Becomes smaller and the capacitance change ΔC becomes smaller. Thereby, the contact detection sensitivity of an electrostatic capacitance sensor falls in the part near the door panel of a sensor electrode. Therefore, the present invention can prevent erroneous detection that the user has touched the door handle when rainwater has accumulated on the boundary between the upper surface of the door handle and the door panel.

The capacitive contact detection device according to the present invention is:
A capacitive contact detection device that detects contact when a user contacts the surface of a door handle outside the vehicle,
A first capacitance sensor configured by forming a capacitor in cooperation with a conductor near the sensor electrode by a first sensor electrode provided near a door panel of the door handle;
A second capacitance sensor configured by forming a capacitor in cooperation with a conductor in the vicinity of the sensor electrode by a second sensor electrode provided at a portion far from the door panel of the door handle;
A detection unit that detects that the user has touched the surface of the door handle based on the total capacitance change ΔC obtained from the following equation (1):
Expression (1) ΔC = w1 × ΔC1 + w2 × ΔC2
ΔC1 is a capacitance change in the first capacitance sensor, ΔC2 is a capacitance change in the second capacitance sensor,
w1 is a weighting factor of ΔC1, w2 is a weighting factor of ΔC2,
w1 is set to a value smaller than w2.

According to the present invention, the total capacitance change ΔC is expressed as ΔC = w1 × ΔC1 + w2 × ΔC2. Rainwater tends to accumulate at the boundary between the upper surface of the door panel and the door handle. When rainwater, which is a conductor, adheres to the boundary between the upper surface of the door handle and the door panel, the rainwater becomes the counterpart electrode of the sensor electrode, and the capacitance change ΔC1 of the first capacitance sensor increases. However, the weighting factor w1 of ΔC1 is smaller than the weighting factor w2 of ΔC2. Therefore, when rainwater collects at the boundary between the upper surface of the door handle and the door panel, the influence of the rainwater on the total capacitance change ΔC is small, and ΔC is small. Therefore, the present invention can prevent erroneous detection that the user has touched the door handle when rainwater accumulates at the boundary between the upper surface of the door handle and the door panel.
In addition, since the weight coefficient w2 of the capacitance change ΔC2 of the second capacitance sensor is large, the influence of ΔC2 on the total capacitance change ΔC is large, and the contact detection sensitivity in the second capacitance sensor is high. . The second sensor electrode is at a position corresponding to a portion of the door handle that is easily touched by the user. Therefore, this invention can detect the contact with high sensitivity, when a user contacts a door handle.

  Capacitive contact detection device that can prevent the user from erroneously detecting contact with the door handle when rainwater collects at the boundary between the upper surface of the door handle and the door panel in a vehicle equipped with a keyless entry system The purpose is to provide.

(First embodiment)
A capacitance type contact detection device according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a capacitance-type contact detection device according to the first embodiment. FIG. 2 is a view showing the vicinity of the sensor electrode of the door handle in the first embodiment, and is a view of the cross section taken along the line AA in FIG. FIG. 3 is a plan view (an arrow view in the direction C in FIG. 1) illustrating an example of the sensor electrode in the first embodiment. FIG. 4 is a plan view showing another example of the sensor electrode in the first embodiment.

  The capacitance-type contact detection device 1 according to the first embodiment detects a contact when a user contacts the surface of the door handle 2 outside the vehicle.

  The capacitance type contact detection device 1 includes a capacitance sensor 3 and a detection unit 4.

  The capacitive contact detection device 1 is electrically connected to a keyless entry system ECU (not shown) including an authentication unit 28, an unlocking unit 29, and a locking unit 30. The door is locked or the like according to the output of the capacitive contact detection device 1. Since the configuration of the authentication unit 28, the unlocking unit 29, and the locking unit 30 is not the essence of the capacitive contact detection device 1, description thereof will be omitted.

The capacitance sensor 3 is configured by a sensor electrode 5 provided on the door handle 2 forming a capacitor in cooperation with a conductor near the sensor electrode 5. The sensor electrode 5 is normally housed in the housing 9 of the door handle 2, but may be exposed on the surface of the door handle 2.
When it is not raining, the metal door panel 6 (see FIG. 2) mainly corresponds to the conductor, and forms a capacitor in cooperation with the sensor electrode 5. However, when rain falls and rainwater adheres to the boundary between the upper surface of the door handle 2 and the door panel 6, the water forms a capacitor in cooperation with the sensor electrode 5 because the water is also a kind of conductor. That is, rainwater becomes the counterpart electrode of the sensor electrode 5.

  In the capacitance sensor 3, the contact detection sensitivity in a portion near the door panel 6 of the sensor electrode 5 is lower than the contact detection sensitivity in a portion far from the door panel 6 of the sensor electrode 5.

  Although the method of setting the contact detection sensitivity in the portion near the door panel 6 of the sensor electrode 5 to be lower than the contact detection sensitivity in the portion far from the door panel 6 of the sensor electrode 5 is not particularly limited, for example, as shown in FIG. Such a setting can be made by forming the notch 8 in the portion of the sensor electrode 5 close to the door panel 6.

The reason why the above setting is possible by forming the notch 8 will be described.
When rainwater as a conductor adheres to the boundary portion between the door handle 2 and the door panel 6, the rainwater becomes the counterpart electrode of the sensor electrode 5 as described above. When the notch 8 is formed in the portion of the sensor electrode 5 close to the door panel 6, the sensor electrode 5 has a small area facing the counterpart electrode (that is, rainwater) in the portion close to the door panel 6. Therefore, in the portion close to the door panel 6, the area S in the capacitance formula: C = ε · (S / d) is reduced, and the capacitance change ΔC is also reduced. Thereby, the contact detection sensitivity of the capacitance sensor 3 decreases in a portion close to the door panel 6.

  Although the number of the notches 8 is not particularly limited, it is preferable that the plurality of notches 8 are uniformly formed in the portion of the sensor electrode 5 close to the door panel 6. Further, the shape of the notch is not particularly limited, but may be, for example, a slit shape (see notch 8 in FIG. 3), a round through hole (see notch 81 in FIG. 4), or a rectangular through hole. As shown in FIG. 3, when a plurality of slits are formed in parallel to each other, the sensor electrode 5 has a comb-like shape near the door panel 6.

  The detection unit 4 is electrically connected to the sensor electrode 5. The detection unit 4 detects that the user has touched the surface of the door handle 2 based on the capacitance change in the capacitance sensor 3. Although the user contact detection method based on a capacitance change is not specifically limited, For example, the detection part 4 can be set as the following structures. That is, the detection unit 4 includes a reference capacitance capacitor having a capacitance larger than that of the capacitance sensor 3, a power supply circuit that charges the reference capacitance capacitor, and the charge accumulated in the reference capacitance capacitor. A semiconductor switch that discharges the sensor electrode 5 until it is fully charged and discharges the charge accumulated in the capacitance sensor 3 to the outside, and a reference capacitance capacitor until the accumulated charge of the reference capacitance capacitor is halved The counting means for counting how many times the discharge has been performed, and the determining means for determining that the user has made contact when the count value becomes less than a predetermined number of times can be employed. According to the detection unit 4 shown in this example, when the capacitance of the capacitance sensor 3 is increased by a user's contact, the amount of electric charge discharged at one time increases, so the count value of the number of discharges decreases. . Therefore, by monitoring the count value of the number of discharges, it is possible to detect the presence or absence of user contact.

  In the first embodiment, user contact detection may be performed by other methods. For example, the detection unit 4 includes a resonance circuit and a power supply circuit that supplies a voltage to the resonance circuit. The resonance circuit changes the amplitude of the output voltage in accordance with the capacitance change of the capacitance sensor 3, and the amplitude thereof. The structure provided with the discrimination | determination means which detects a user's contact based on a change may be sufficient.

  The electrostatic capacitance in the electrostatic capacitance sensor 3 increases when the user contacts the surface of the door handle 2, and also increases when rainwater accumulates at the boundary between the upper surface of the door handle 2 and the door panel 6. However, in the present embodiment, as described below, it is possible to prevent erroneous detection of contact due to rainwater accumulation.

  Next, the operation of the capacitive contact detection device 1 will be described. Note that user authentication and door locking are not features of the present embodiment, and thus description thereof is omitted.

First, the operation when it is not raining will be described.
For example, here, the discharge count method described above is used. When the user contacts the vicinity of the sensor electrode 5 of the door handle 2, the capacitance of the capacitance sensor 3 increases, and the number of discharges from the reference capacitance capacitor becomes less than a predetermined number (threshold). Therefore, the capacitance-type contact detection device 1 can detect that the user has touched the door handle 2 by determining that the number of discharges is less than the predetermined number.

Next, the operation will be described when it is raining.
Here again, the above-described discharge count method is used. The operation when the user touches the door handle 2 is the same as when it is not raining.

  On the other hand, when it is raining but the user is not in contact with the door handle 2, the rainwater tends to collect on the boundary between the upper surface of the door handle 2 and the door panel 6. When rainwater accumulates at this boundary portion, the rainwater cooperates with the sensor electrode 5 to form a capacitor. However, in the example shown in FIG. 3, the notch 8 is formed in the portion of the sensor electrode 5 close to the door panel 6. Thereby, as for the electrostatic capacitance sensor 3, the contact detection sensitivity in the part near the door panel 6 of the sensor electrode 5 is lower than the contact detection sensitivity in the part far from the door panel 6 of the sensor electrode 5. Therefore, the capacitive contact detection device 1 can prevent erroneous detection that the user has touched the door handle 2 when rainwater has accumulated on the boundary portion between the upper surface of the door handle 2 and the door panel 6.

  Moreover, since the contact detection sensitivity in the part far from the door panel 6 of the sensor electrode 5 remains high, the electrostatic capacitance type contact detection device 1 detects the contact with high sensitivity when the user touches the door handle 2. Can do.

  In addition, even if it uses the sensor electrode 51 which formed the several through-hole as the notch part 81 as FIG. 4 shows, there can exist an effect similar to the example shown in FIG.

(Second Embodiment)
A capacitance type contact detection device according to a second embodiment of the present invention will be described with reference to the drawings.

  FIG. 5 is a perspective view showing a capacitive contact detection device according to the second embodiment. FIG. 6 is a view showing the vicinity of the sensor electrode of the door handle in the second embodiment, and is a view of the AA line cross section of FIG. 5 as seen from the B direction.

  In addition, about the structure similar to 1st Embodiment, the code | symbol similar to 1st Embodiment is attached | subjected and the description is abbreviate | omitted.

  In the first embodiment, in order to make the contact detection sensitivity in a portion near the door panel 6 of the sensor electrode 5 lower than the contact detection sensitivity in a portion far from the door panel 6 of the sensor electrode 5, as shown in FIG. In the second embodiment, instead of this, the thickness of the housing 32 of the door handle 2 is devised.

  In the second embodiment, as shown in FIG. 6, the sensor electrode 10 is accommodated in the housing 32 of the door handle 11. In the case 32, the thickness of the portion near the door panel 6 in the vicinity of the sensor electrode 10 is larger than the thickness of the portion far from the door panel 6.

  When rainwater, which is a conductor, adheres to the boundary between the upper surface of the door handle 11 and the door panel 6, the rainwater becomes the counterpart electrode of the sensor electrode 10. When the thickness of the portion near the door panel 6 of the housing 32 is larger than the thickness of the portion far from the door panel 6 of the housing 32, the distance between the portion of the sensor electrode 10 near the door panel 6 and the counterpart electrode (ie, rainwater) is The distance between the portion of the sensor electrode 10 far from the door panel 6 and the counterpart electrode (that is, rainwater) becomes larger. Therefore, in the portion of the sensor electrode 10 close to the door panel 6, the distance d in the capacitance formula: C = ε · (S / d) increases, and the capacitance change amount ΔC decreases. Thereby, the contact detection sensitivity of the capacitance sensor 12 decreases in a portion close to the door panel 6. Therefore, the capacitive contact detection device 13 according to the second embodiment erroneously detects that the user has touched the door handle 11 when rainwater has accumulated on the boundary between the upper surface of the door handle 11 and the door panel 6. Can be prevented.

(Third embodiment)
A capacitance type contact detection device according to a third embodiment of the present invention will be described with reference to the drawings.

  FIG. 7 is a perspective view showing a capacitance type contact detection device according to the third embodiment. FIG. 8 is a view showing the vicinity of the sensor electrode of the housing of the door handle in the third embodiment, and is a view of the cross section taken along the line AA in FIG. 7 from the B direction.

  In addition, about the structure similar to 2nd Embodiment, the code | symbol similar to 2nd Embodiment is attached | subjected and the description is abbreviate | omitted.

  Differences from the second embodiment will be described. In the second embodiment, the thickness of the housing 32 of the door handle 11 is devised as illustrated in FIG. In the third embodiment, instead of this, the dielectric constant of the housing 15 of the door handle 14 is devised.

As shown in FIG. 8, the sensor electrode 10 is housed in a housing 15 of the door handle 14.
In the case 15, in the vicinity of the sensor electrode 10, the dielectric constant of the portion near the door panel 6 is smaller than the dielectric constant of the portion far from the door panel 6.

  When rainwater, which is a conductor, adheres to the boundary between the upper surface of the door handle 14 and the door panel 6, the rainwater becomes the counterpart electrode of the sensor electrode 10. When the dielectric constant of the portion near the door panel 6 of the housing 15 is smaller than the dielectric constant of the portion far from the door panel 6 of the housing 15, the capacitance formula C = The dielectric constant ε in ε · (S / d) decreases, and the amount of change ΔC in capacitance decreases. As a result, the contact detection sensitivity of the capacitance sensor 17 decreases at a portion of the sensor electrode 10 close to the door panel 6. Therefore, the capacitive contact detection device 18 according to the third embodiment erroneously detects that the user has touched the door handle 14 when rainwater has accumulated on the boundary between the upper surface of the door handle 14 and the door panel 6. Can be prevented.

(Fourth embodiment)
A capacitance type contact detection device according to a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a perspective view showing a capacitive contact detection device according to the fourth embodiment. FIG. 10 is a view showing the vicinity of the sensor electrode of the housing of the door handle in the fourth embodiment, and is a view of the cross section taken along the line AA in FIG. 9 from the B direction.

  In addition, about the structure similar to 1st Embodiment, the code | symbol similar to 1st Embodiment is attached | subjected and the description is abbreviate | omitted.

  In the said 1st Embodiment, although the misdetection of the user contact was prevented by devising the shape of the sensor electrode 5 so that it may be illustrated by FIG. 3, in 4th Embodiment, the calculation process in the detection part 24 is performed. By devising, false detection of user contact is prevented.

  The capacitance-type contact detection device 21 according to the fourth embodiment includes a first capacitance sensor 22, a second capacitance sensor 23, and a detection unit 24.

  The first capacitance sensor 22 is configured by a first sensor electrode 20 provided in a portion near the door panel 6 of the door handle 2 forming a capacitor in cooperation with a conductor near the sensor electrode 20. The In the example shown in FIG. 10, the first sensor electrode 20 is accommodated in the housing 9 of the door handle 2.

  The second capacitance sensor 23 is configured by a second sensor electrode 26 provided in a portion of the door handle 2 far from the door panel 6 in cooperation with a conductor near the sensor electrode 26 to form a capacitor. The In the example shown in FIG. 10, the second sensor electrode 26 is accommodated in the housing 9 of the door handle 2.

  The detection unit 24 is electrically connected to the first sensor electrode 20 and the second sensor electrode 26. The detection unit 24 detects that the user has touched the surface of the door handle 2 based on the total capacitance change ΔC obtained from the following equation (1).

  Expression (1) ΔC = w1 × ΔC1 + w2 × ΔC2

  ΔC1 is a capacitance change in the first capacitance sensor 22, and ΔC2 is a capacitance change in the second capacitance sensor 23. w1 is a weighting factor of ΔC1, and w2 is a weighting factor of ΔC2. w1 is set to a value smaller than w2.

  In the capacitance-type contact detection device 21, the total capacitance change ΔC is represented by ΔC = w1 × ΔC1 + w2 × ΔC2. Rainwater tends to accumulate on the boundary between the upper surface of the door panel 6 and the door handle 2. When rainwater, which is a conductor, adheres to the boundary between the upper surface of the door handle 2 and the door panel 6, the rainwater becomes the counterpart electrode of the sensor electrode, and the capacitance change ΔC1 of the first capacitance sensor 22 increases. However, the weighting factor w1 of ΔC1 is smaller than the weighting factor w2 of ΔC2. Therefore, when rainwater accumulates at the boundary between the upper surface of the door handle 2 and the door panel 6, the influence of the rainwater on the total capacitance change ΔC is small, and ΔC is small. Therefore, the capacitance-type contact detection device 21 can prevent erroneous detection that the user has touched the door handle 2 when rainwater has accumulated on the boundary between the upper surface of the door handle 2 and the door panel 6.

  Further, since the weight coefficient w2 of the capacitance change ΔC2 of the second capacitance sensor 23 is large, the influence of ΔC2 on the total capacitance change ΔC is large, and the contact detection sensitivity in the second capacitance sensor 23 is large. Is expensive. The 2nd sensor electrode 26 exists in the position corresponding to the part which the user of the door handle 2 touches easily. Therefore, the capacitive contact detection device 21 can detect the contact with high sensitivity when the user contacts the door handle 2.

Here, an operation example of the capacitance-type contact detection device 21 will be described.
Assume that the weighting factor w1 of ΔC1 is set to 0.5 and the weighting factor w2 of ΔC2 is set to 1.0. Next, it is assumed that ΔC1 becomes 0.5 pF and ΔC2 becomes 1.5 pF by the user touching the surface of the door handle 2. In this case, the total capacitance change ΔC is
ΔC = 0.5 × 0.5 + 1.0 × 1.5 = 1.75 (pF)

  The detection unit 24 determines that the user has touched the door handle 2 when the threshold value of ΔC for determining that the user has touched the door handle 2 is set to 1.5 pF and the measured value of ΔC is equal to or greater than this threshold value. Assume that the settings have been made.

  In this case, since the measured value 1.75 pF of ΔC is larger than the threshold value 1.5 pF of ΔC, the detection unit 24 determines that the user has touched the door handle 2.

On the other hand, it is assumed that ΔC1 becomes 1.5 pF and ΔC2 becomes 0.5 pF when rainwater is collected on the upper surface of the door handle 2 but the user is not in contact with the door handle 2. In this case, the total capacitance change ΔC is
ΔC = 0.5 × 1.5 + 1.0 × 0.5 = 1.25 (pF)

  In this case, since the measured value 1.25 pF of ΔC is smaller than the threshold value 1.5 pF of ΔC, the detection unit 24 does not erroneously determine that the user has touched the door handle 2.

  In each of the above embodiments, the case where the capacitive contact detection device is applied to a contact detection device for locking has been described. However, the capacitive contact detection device is applied to a contact detection device for unlocking. It is also possible to do.

  INDUSTRIAL APPLICABILITY The present invention is useful for a capacitive contact detection device that does not falsely detect that a user has touched the door handle when rainwater has accumulated on the boundary between the upper surface of the door handle and the door panel in a vehicle equipped with a keyless entry system. It is.

The perspective view which shows the electrostatic capacitance type contact detection apparatus which concerns on 1st Embodiment. It is the figure which extracted and shows the sensor electrode vicinity of the door handle in 1st Embodiment, and is the figure which looked at the AA line cross section in FIG. The top view which shows an example of the sensor electrode in 1st Embodiment (C direction arrow line view of FIG. 1) The top view which shows the other example of the sensor electrode in 1st Embodiment. The perspective view which shows the electrostatic capacitance type contact detection apparatus which concerns on 2nd Embodiment. It is the figure which extracted and shows the sensor electrode vicinity of the door handle in 2nd Embodiment, and the figure which looked at the AA line cross section of FIG. 5 from the B direction The perspective view which shows the electrostatic capacitance type contact detection apparatus which concerns on 3rd Embodiment. It is the figure which extracted and shows the sensor electrode vicinity of the housing | casing of the door handle in 3rd Embodiment, and is the figure which looked at the AA line cross section of FIG. The perspective view which shows the electrostatic capacitance type contact detection apparatus which concerns on 4th Embodiment. It is the figure which extracted and shows the sensor electrode vicinity of the housing | casing of the door handle in 4th Embodiment, and is the figure which looked at the AA line cross section of FIG. A perspective view showing a conventional door handle

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 13, 18, 21 Capacitance type contact detection apparatus 2, 11, 14 Door handle 3, 12, 17 Capacitance sensor 4, 24 Detection part 5, 10, 16 Sensor electrode 6 Door panel 8, 81 Notch 9 , 15 Housing 20 First sensor electrode 22 First capacitance sensor 23 Second capacitance sensor 26 Second sensor electrode

Claims (5)

A capacitive contact detection device that detects contact when a user contacts the surface of a door handle outside the vehicle,
A capacitance sensor configured by forming a capacitor in cooperation with a conductor near the sensor electrode provided on the door handle;
A detection unit that detects that a user has contacted the surface of the door handle based on a change in capacitance in the capacitance sensor;
The capacitance-type contact detection device according to claim 1, wherein a contact detection sensitivity at a portion of the sensor electrode near the door panel is lower than a contact detection sensitivity at a portion far from the door panel of the sensor electrode.   The capacitive contact detection device according to claim 1, wherein the sensor electrode has a notch formed in a portion near the door panel. The sensor electrode is housed in a housing of the door handle,
2. The capacitive contact detection device according to claim 1, wherein a thickness of a portion near the door panel is greater than a thickness of a portion far from the door panel in the vicinity of the sensor electrode. The sensor electrode is housed in a housing of the door handle,
2. The electrostatic capacitance type contact detection device according to claim 1, wherein a dielectric constant of a portion near the door panel near the sensor electrode is smaller than a dielectric constant of a portion far from the door panel. . A capacitive contact detection device that detects contact when a user contacts the surface of a door handle outside the vehicle,
A first capacitance sensor configured by a first sensor electrode provided near a door panel of the door handle forming a capacitor in cooperation with a conductor near the sensor electrode;
A second capacitance sensor configured by forming a capacitor in cooperation with a conductor in the vicinity of the sensor electrode by a second sensor electrode provided in a portion of the door handle remote from the door panel;
A detection unit that detects that the user has contacted the surface of the door handle based on a total capacitance change ΔC obtained from the following equation (1):
Expression (1) ΔC = w1 × ΔC1 + w2 × ΔC2
ΔC1 is a capacitance change in the first capacitance sensor, ΔC2 is a capacitance change in the second capacitance sensor,
w1 is a weighting factor of ΔC1, w2 is a weighting factor of ΔC2,
w1 is set to a value smaller than w2, The electrostatic capacitance type touch detection apparatus characterized by the above-mentioned.

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