JP2010139362A - Capacitance type contact detection device, door handle, and smart entry system - Google Patents

Abstract

Provided is a capacitance type contact detection device capable of accurately detecting contact of a bare hand on a door handle and contact of a hand wearing a glove while preventing erroneous contact detection due to raindrops adhering to the door handle. .
A capacitive contact detection device for detecting a user's contact with a door handle outside a vehicle, wherein a sensor electrode provided in the door handle cooperates with a conductor in the vicinity of the sensor electrode. A capacitance sensor formed by forming a capacitor and provided in each of the two or more door handles, and when the amount of change in capacitance in the capacitance sensor is equal to or greater than a first threshold, A contact detection unit that determines that the user has touched the surface of the door handle; and at least any two of the door handles, when the amount of change in the capacitance of each capacitance sensor has a predetermined change, A threshold value changing unit for changing the first threshold value.
[Selection] Figure 4

Description

  The present invention relates to a capacitive contact detection device, a door handle, and a smart entry system. More specifically, the present invention relates to a contact with a bare hand and a glove attached to the door handle while preventing erroneous contact detection due to raindrops on the door handle. The present invention relates to a capacitance type contact detection device capable of detecting a touch of a hand, a door handle provided with the capacitance type contact detection device, and a smart entry system.

  Conventionally, as exemplified in Patent Document 1, a technology has been realized in which a capacitive contact detection device is provided on the outer door handle of a vehicle, and the door is locked and unlocked according to the detection result of the contact detection device. ing. In this contact detection device, a sensor electrode provided on a door handle forms a capacitor with a conductor in the vicinity of the electrode, and detects a user's contact with the door handle based on a change in capacitance of the capacitor. It is.

  However, when it rains, raindrops may adhere to the surface of the outer door handle. When raindrops adhere to the outer door handle, the raindrops as conductors form electrodes, thereby increasing the capacitance of the capacitor. Then, the contact detection device may erroneously determine that the increase in capacitance due to raindrops is an increase in capacitance due to user contact. If there is such an erroneous determination, there is a problem that the door is locked or unlocked against the user's will.

Moreover, the following problems existed in the capacitance-type contact detection device that has been developed for vehicles in recent years.
Some recent capacitive contact detection devices detect user contact based on the amount of change in capacitance (ΔC).
FIG. 17 shows the amount of change in capacitance when a bare hand touches (ΔC), the amount of change in capacitance when a hand wearing a glove touches (ΔC), and the capacitance when raindrops adhere. Is a normal distribution diagram (in order, S1, S2, and S3) showing the amount of change (ΔC). This example shows a case where the user wears thin gloves.

  As shown in FIG. 17, normally, the normal distribution of the amount of change in capacitance (ΔC) when a bare hand touches, the normal amount of the amount of change in capacitance (ΔC) when a hand wearing a glove touches In the normal distribution of the distribution and the amount of change in capacitance (ΔC) when raindrops adhere, the value of the center of gravity position decreases in this order. Further, the normal distribution map S1 and the normal distribution map S2 have overlapping skirts, and the normal distribution map S2 and the normal distribution map S3 have overlapping skirts.

  In such a situation, in order to reduce the possibility of erroneous contact detection at the time of raindrop adhesion, the threshold value THC1 of the change amount of the capacitance is fixedly set at one end (the side where the capacitance is small) of the normal distribution diagram S1. It is possible to do. The capacitance type contact detection device determines that the user has touched the door handle if the measured value of the change amount of the capacitance exceeds the threshold value THC1, and if the measured value of the change amount of the capacitance is less than the threshold value THC1. The user determines that the door handle is not touching. In this case, the capacitive contact detection device can reduce the possibility of erroneous contact detection when raindrops adhere. However, since about half of the normal distribution map S2 is on the lower level side than the threshold THC1, when the measured value of the change in capacitance is located in that portion, the capacitance type contact detection device does not wear gloves. It cannot be detected that the attached hand has touched the door handle.

  Further, in order to improve the contact detection accuracy of the hand wearing the glove, it is conceivable that the threshold value THC2 is fixedly set at one end of the normal distribution diagram S2 (the side with the smaller capacitance). In this case, the capacitance-type contact detection device can detect contact of a hand wearing a glove with high accuracy. However, since about half of the normal distribution map S3 is on the higher level side than the threshold value THC2, when the measured value of the change in capacitance is located in that portion, the capacitive contact detection device Will be falsely detected as touching the door handle.

As described above, in the conventional capacitance-type contact detection device, the threshold value of the change amount (ΔC) of the capacitance is fixedly set (set to a constant value). It was difficult to achieve both the prevention of erroneous contact detection and the accurate detection of contact with a bare hand on the door handle and contact with a hand wearing gloves.
JP 2006-508283 A

  The present invention has been made in view of such circumstances, and accurately detects contact of a bare hand on the door handle and contact of a hand wearing gloves while preventing erroneous contact detection due to raindrops adhering to the door handle. Capacitive contact detection device capable of performing detection, capacitive contact detection device capable of accurately detecting rainfall, and door handle and smart entry provided with these capacitive contact detection devices The purpose is to provide a system.

The first invention is
A capacitive contact detection device that detects a user's contact with a door handle outside the vehicle,
A sensor electrode provided in the door handle is configured by forming a capacitor in cooperation with a conductor near the sensor electrode, and a capacitance sensor provided in each of the two or more door handles;
A contact detection unit that determines that the user has touched the surface of the door handle when the amount of change in capacitance in the capacitance sensor is equal to or greater than a first threshold;
Capacitance-type contact detection, comprising: a threshold value changing unit that changes the first threshold value when the capacitance of each of the capacitance sensors changes a predetermined value in at least any two of the door handles. Device.

  According to the first aspect, the threshold value changing unit changes the first threshold value when the capacitance of each capacitance sensor changes at a predetermined value in at least any two door handles. That is, the first threshold value is changed based on the change in the capacitances of the two or more door handles. When the weather changes, such as from clear weather to rain, from rainy weather to clear weather, it is considered that the same capacitance change occurs in two or more door handles. Therefore, by changing the first threshold based on the change in the capacitances of two or more door handles, the threshold changing unit can change the first threshold to an appropriate value according to the weather. It becomes possible. This provides a capacitive contact detection device that can accurately detect the contact of a bare hand on the door handle and the hand wearing a glove while preventing erroneous contact detection due to raindrops on the door handle. can do.

The second invention is
In the first invention,
The threshold value changing unit increases the first threshold value when the capacitance of each of the capacitance sensors increases a predetermined amount in at least any two of the door handles.

  According to the second aspect of the present invention, even when the weather changes from sunny to rainy and when the amount of rain increases in the rain, contact with the bare handle to the door handle is prevented while preventing erroneous contact detection due to raindrops adhering to the door handle. In addition, it is possible to accurately detect the contact of a hand wearing a glove.

The third invention is
In the second invention,
The contact detection unit detects the capacitance at a predetermined time period,
When the increase of each of the capacitances by n periods (n is an arbitrary positive number) exceeds a second threshold value in at least any two of the door handles, the threshold value changing unit is configured to The threshold value is changed from a value for the first state to a value for the second state.

  According to the third aspect, when the first state (for example, clear sky state) is changed to the second state (for example, rainy state), the first threshold is changed from the value for the first state to the second state. Is changed to the value for Therefore, even if it will be in a 2nd state, the contact detection of the bare hand to a door handle and the contact of the hand which put on the glove can be detected correctly, preventing the erroneous detection of contact by raindrops adhering to a door handle.

The fourth invention is:
In the second invention,
The contact detection unit detects the capacitance at a predetermined time period,
When the increase of each of the capacitances by n cycles (n is an arbitrary positive number) exceeds a third threshold value in at least any two of the door handles, the threshold value changing unit is configured to The threshold value is changed from the value for the third state to the value for the fourth state, or the value for the fourth state is changed to the value for the fifth state.

  According to the fourth invention, when the third state (for example, a light rain state) changes to the fourth state (for example, a light rain state) or from the fourth state (for example, a light rain state) When the state changes to a state of 5 (for example, a heavy rain state), the threshold value changing unit changes the first threshold value from the value for the first state to the value for the second state, or the fourth state. The value for the fifth state is changed to the value for the fifth state. Therefore, even if the rainfall changes, it is possible to accurately detect the contact of the bare hand to the door handle and the contact of the hand wearing the glove while preventing the erroneous contact detection due to the raindrop adhering to the door handle.

The fifth invention is:
In the first invention,
The threshold value changing unit lowers the first threshold value when at least one of the two door handles has a predetermined decrease in capacitance of each of the capacitance sensors.

  According to the fifth aspect of the present invention, even when the weather is changed from rainy weather to rainy weather and when the amount of rain is reduced in the rainy weather, the contact of the bare hand to the door handle is prevented while preventing erroneous contact detection due to raindrops adhering to the door handle. In addition, it is possible to accurately detect the contact of a hand wearing a glove.

The sixth invention is:
In the fifth invention,
The contact detection unit detects the capacitance at a predetermined time period,
When at least one of the two door handles has a state where the decrease of each of the capacitances by n cycles (n is an arbitrary positive number) is less than a fourth threshold for a predetermined time, the threshold value changing unit The first threshold value is changed from a value for the second state to a value for the first state.

  According to the sixth aspect, when the second state (for example, rainy weather condition) changes to the first state (for example, fine weather condition), the first threshold value is changed from the value for the second state to the first state. Is changed to the value for Therefore, even when the second state changes to the first state, the detection of contact with raindrops on the door handle and the detection of contact with bare hands and the hand with gloves are accurately detected while preventing contact detection. be able to.

The seventh invention
The contact detection unit detects the capacitance at a predetermined time period,
When at least one of the two door handles has a state where the decrease of each of the capacitances by n cycles (n is an arbitrary positive number) is less than a fifth threshold for a predetermined time, the threshold value changing unit The first threshold value is changed from a value for the fourth state to a value for the third state, or a value for the fifth state is changed to a value for the fourth state. To do.

  According to the seventh aspect, when the state changes from the fourth state (for example, a medium rainy state) to the third state (for example, a light rainy state) or from the fifth state (for example, a heavy rainy state) to the fourth state. The threshold value changing unit changes the first threshold value from the value for the fourth state to the value for the third state, or changes to the fifth state. The value for is changed to the value for the fourth state. Therefore, even if the rainfall changes, it is possible to accurately detect the contact of the bare hand to the door handle and the contact of the hand wearing the glove while preventing the erroneous contact detection due to the raindrop adhering to the door handle.

The eighth invention
In the third or sixth invention,
The first state is a clear sky state, and the second state is a rainy state.

  According to the eighth aspect of the present invention, contact between a bare hand and a hand wearing gloves is prevented while preventing erroneous contact detection due to raindrops adhering to the door handle even when the weather changes from fine weather to rainy weather. It can be detected accurately.

The ninth invention
In the fourth or seventh invention,
The third state is a light rain state, the fourth state is a medium rain state, and the fifth state is a heavy rain state.

  According to the ninth invention, even if the rainfall changes, such as light rain to medium rain, medium rain to heavy rain, medium rain to light rain, or heavy rain to heavy rain, While preventing erroneous contact detection due to raindrop adhesion, it is possible to accurately detect the contact of a bare hand to the door handle and the contact of a hand wearing a glove.

The tenth invention is
A capacitive contact detection device that detects a user's contact with a door handle outside the vehicle,
A sensor electrode provided in the door handle is configured by forming a capacitor in cooperation with a conductor near the sensor electrode, and a capacitance sensor provided in each of the two or more door handles;
A contact detection unit that determines that the user has touched the surface of the door handle when the capacitance of the capacitance sensor is equal to or greater than a sixth threshold;
Capacitance-type contact detection comprising: a threshold value changing unit that changes the sixth threshold value when the capacitance of each of the capacitance sensors changes a predetermined value in at least any two of the door handles. Device.

  According to the tenth aspect, the threshold value changing unit changes the sixth threshold value when the capacitance of each capacitance sensor has changed a predetermined value in at least any two door handles. That is, the sixth threshold value is changed based on the change in the electrostatic capacity of two or more door handles. When the weather changes, such as from clear weather to rain, from rainy weather to clear weather, it is considered that the same capacitance change occurs in two or more door handles. Therefore, by changing the sixth threshold based on the change in the capacitances of two or more door handles, the threshold changing unit can change the sixth threshold to an appropriate value according to the weather. It becomes possible. This provides a capacitive contact detection device that can accurately detect the contact of a bare hand on the door handle and the hand wearing a glove while preventing erroneous contact detection due to raindrops on the door handle. can do.

The eleventh invention is
A door handle provided with the capacitive contact detection device according to any one of the first to tenth aspects of the invention.

  According to the eleventh aspect of the present invention, it is possible to accurately detect contact of a bare hand to the door handle and contact of a hand wearing a glove while preventing erroneous contact detection due to raindrops adhering to the door handle even if the rainfall changes. A door handle can be provided.

The twelfth invention
A smart entry system for locking or unlocking a vehicle door by touching a door handle,
The door handle includes the door handle of the eleventh invention.

  According to the twelfth aspect of the present invention, it is possible to accurately detect contact of a bare hand to the door handle and contact of a hand wearing a glove while preventing erroneous contact detection due to raindrops adhering to the door handle even if the rainfall changes. It is possible to provide a smart entry system having a door handle that can be used.

The thirteenth invention
A capacitive contact detection device for detecting rain contact with a door handle outside the vehicle,
A sensor electrode provided in the door handle is configured by forming a capacitor in cooperation with a conductor near the sensor electrode, and a capacitance sensor provided in each of the two or more door handles;
A detection unit for detecting the capacitance of the capacitance sensor or a change amount of the capacitance;
A capacitance-type contact detection device comprising: a rain judgment unit that judges that it is raining when the capacitance of each of the capacitance sensors in the at least any two of the door handles changes a predetermined amount. It is.

  According to the thirteenth aspect, the rain determining unit determines that it is raining when the electrostatic capacity of each electrostatic capacity sensor in the at least one of the two door handles changes in a predetermined manner. That is, the rain determining unit determines that it is raining based on the capacitance changes in the two or more door handles. When the weather changes, such as from clear weather to rain, from rainy weather to clear weather, it is considered that the same capacitance change occurs in two or more door handles. Therefore, by determining that it is raining based on each capacitance change in the two or more door handles, the rain determination unit can accurately detect the rain.

The fourteenth invention is
In the thirteenth invention,
The detection unit detects the capacitance at a predetermined time period,
When at least one of the two door handles has an increase of n periods (n is an arbitrary positive number) of the capacitances equal to or greater than a threshold value, the rain determination unit determines that it is raining. It is characterized by that.

  According to the fourteenth aspect of the present invention, the rain judgment unit only detects whether the increase in the n periods (n is an arbitrary positive number) of the capacitance of each capacitance sensor has reached or exceeded the threshold value. It can be determined that it is falling.

The fifteenth invention
A door handle provided with the capacitance type contact detection device of the thirteenth or fourteenth invention.

  According to the fifteenth aspect, it is possible to provide a door handle capable of accurately detecting rainfall.

The sixteenth invention is
A smart entry system for locking or unlocking a vehicle door by touching a door handle,
The door handle includes the door handle of the fifteenth aspect of the invention.

  According to the sixteenth aspect of the present invention, it is possible to accurately detect contact of a bare hand to the door handle and contact of a hand wearing a glove while preventing erroneous contact detection due to raindrops adhering to the door handle even if the rainfall changes. It is possible to provide a smart entry system having a door handle that can be used.

  According to the present invention, erroneous contact detection due to disturbance such as raindrops can be reduced.

(First embodiment)
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an arrangement example of door handles provided with sensor electrodes of the capacitive contact detection device according to the first embodiment. FIG. 2 is a top view showing the door handle provided with the sensor electrode of the capacitive contact detection device according to the first embodiment. FIG. 3 is a side view showing a door handle provided with sensor electrodes of the capacitive contact detection device according to the first embodiment. FIG. 4 is a diagram illustrating the capacitive contact detection device according to the first embodiment.

  The capacitance-type contact detection device 1 according to the first embodiment is a device that detects a contact when a user contacts the surface of a door handle 2 (see FIGS. 1 to 3) outside the vehicle 30 (see FIG. 1). is there. Reference numeral 31 in FIG. 1 denotes a door. Although the material of the main body of the door handle 2 is not specifically limited, For example, it is a product made from a dielectric material. An example of the dielectric is synthetic resin.

  As shown in FIG. 4, the capacitance-type contact detection device 1 includes a capacitance sensor 3, a contact detection unit 4, and a threshold value changing unit 12.

  The capacitive contact detection device 1 is connected to a door locking device 9. The capacitance-type contact detection device 1 detects that the user's hand has touched the front upper surface of the door handle 2 and outputs a contact detection signal to the door locking device 9. The door locking device 9 locks the door 31 when a contact detection signal is input.

  The capacitance sensor 3 is configured by a sensor electrode 5 provided inside the door handle 2 forming a capacitor in cooperation with a conductor near the sensor electrode 5. The conductor is, for example, the door panel 8 to which the door handle 2 is attached or a user's finger. The sensor electrode 5 is provided on the upper surface side of the front portion of the door handle 2. The sensor electrode 5 is for detecting that the user has touched the front upper surface of the door handle 2. Capacitance sensors 3 are provided on at least two door handles 2, respectively. In the example shown in FIGS. 1 and 4, the capacitance sensor 3 includes a door handle 2 for a driver side door, a door handle 2 for a passenger side door, a door handle 2 for a right rear seat side door, and a left rear portion. It is provided in each door handle 2 of the seat side door.

  The contact detection unit 4 measures the amount of change in capacitance (ΔC) in the capacitance sensor 3, and when the amount of change in capacitance (ΔC) exceeds the first threshold value TH1, the corresponding door It is determined that the user has touched the surface of the handle 2. The method for measuring the amount of change in capacitance (ΔC) is not particularly limited.

  The threshold value changing unit 12 changes the first threshold value TH1 when at least one of the two door handles 2 has a predetermined change in the capacitance of each capacitance sensor 3.

  The threshold value changing unit 12 will be described in more detail. FIG. 5 shows the amount of change in capacitance when a bare hand touches (ΔC), the amount of change in capacitance when a hand wearing gloves touches (ΔC), and the capacitance when raindrops adhere. It is a figure which shows the relationship between each normal distribution (it is set to S1, S2, S3 in order) of the variation | change_quantity ((DELTA) C), and 1st threshold value TH1 in a 1st state (for example, clear sky state). This example shows a case where the user wears thin gloves.

  As shown in FIG. 5, the center of gravity position of the normal distribution of the amount of change in capacitance (ΔC) is usually in descending order of capacitance when bare hands touch (see S1) and gloves are worn. It becomes the electrostatic capacity when the hand touches (see S2) and the electrostatic capacity when raindrops adhere (see S3). Further, the normal distribution map S1 and the normal distribution map S2 have overlapping skirts, and the normal distribution map S2 and the normal distribution map S3 have overlapping skirts.

  The threshold value changing unit 12 determines that it has started to rain when the capacitance of each capacitance sensor 3 has increased by a predetermined amount in at least any two door handles 2, or has determined that the rainfall has increased. The threshold value TH1 of 1 is increased.

  Specifically, the contact detection unit 4 detects the amount of change in capacitance (ΔC) for each capacitance sensor 3 at a predetermined time period. When this period is converted into a frequency, for example, detection is performed at a frequency of about 1 MHz. When at least one of the two door handles 2 increases each capacitance by n cycles (n is an arbitrary positive number) equal to or greater than the second threshold, the threshold changing unit 12 sets the first threshold TH1. Is changed from a value for the first state (for example, clear weather state) to a value for the second state (for example, rainy state). For example, the threshold value changing unit 12 changes the first threshold value TH1 from the fine weather threshold value A (see FIG. 5) to the rainy time threshold value B (see FIG. 6).

  For example, as shown in FIG. 5, the clear sky threshold A is set in the vicinity of one end of the normal distribution map S <b> 2 (the side with the smaller capacitance). If the measured value of the change amount (ΔC) of the capacitance exceeds the threshold A, the contact detection unit 4 determines that the user has touched the corresponding door handle 2, and the measured value of the change amount (ΔC) of the capacitance. Is less than the threshold A, it is determined that the user does not touch the corresponding door handle 2. In this case, the contact detection unit 4 can accurately detect both a user contact with a bare hand and a user contact with a gloved hand in fine weather.

  For example, as shown in FIG. 6, the rainfall threshold B is set in the vicinity of one end of the normal distribution map S <b> 1 (capacitance is smaller). After the first threshold value TH1 is changed from the clear-time threshold value A to the rainy-time threshold value B, the contact detection unit 4 determines that the measured value of the amount of change in capacitance (ΔC) exceeds the threshold value B, If the measured value of the change amount (ΔC) of the capacitance is less than the threshold value B, it is determined that the user is not in contact with the door handle 2. In this case, the contact detection unit 4 can accurately detect both a user contact with a bare hand and a user contact with a gloved hand in rainy weather. Moreover, erroneous contact detection due to raindrops adhering to the door handle 2 is prevented.

  It is also possible to change the first threshold value TH1 during rainy weather according to the rainfall. For example, when the increase in n capacitances (n is an arbitrary positive number) of each capacitance in the at least any two door handles 2 is equal to or greater than a third threshold, the threshold changing unit 12 The threshold value TH1 is changed from a value B1 (see FIG. 7) for the third state (for example, a light rain state) to a value B2 (see FIG. 8) for a fourth state (for example, a medium rain state), or The value B2 (see FIG. 8) for the fourth state (eg, heavy rain state) is changed to the value B3 (see FIG. 9) for the fifth state (eg, heavy rain state). As shown in FIGS. 7 to 9, B1, B2, and B3 are, for example, between one end of the normal distribution map S1 (the smaller capacitance side) and one end of the normal distribution map S2 (the smaller capacitance side). In this order, it is set to gradually increase.

  Further, the threshold value changing unit 12 determines that the rain has stopped or the rain amount has decreased when the capacitance of each of the capacitance sensors 3 has decreased by a predetermined amount in at least any two door handles 2. Then, the first threshold value TH1 is lowered.

  Specifically, when at least one of the two door handles 2 has a state in which the decrease of each capacitance by n cycles (n is an arbitrary positive number) is less than the fourth threshold for a predetermined time, the threshold value The changing unit 12 changes the first threshold value TH1 from a value for the second state (for example, a rainy weather state) to a value for the first state (for example, a clear sky state). For example, the threshold changing unit 12 changes the first threshold TH1 from the rainy day threshold B (see FIG. 6) to the clear sky threshold A (see FIG. 5).

  Further, when at least one of the two door handles 2 has a state in which the decrease of each cycle by n cycles (n is an arbitrary positive number) is less than the fifth threshold value for a predetermined time, the threshold value changing unit 12 Changes the first threshold value TH1 from the value B2 (see FIG. 8) for the fourth state (for example, medium rain) to the value B1 (see FIG. 7) for the third state (for example, light rain). Alternatively, the value B3 (see FIG. 9) for the fifth state (for example, heavy rain state) is changed to the value B2 (see FIG. 8) for the fourth state (for example, medium rain state).

FIG. 10 is a flowchart illustrating an example of the operation of the threshold changing unit 12.
As shown in FIG. 10, the threshold value changing unit 12 first sets the first threshold value TH1 to the fine weather threshold value A (step S1). Next, the threshold value changing unit 12 determines whether or not the capacitance has increased by a predetermined amount in at least two door handles 2 based on the change in capacitance measured by the contact detection unit 4 (step S2). It is considered that when at least two door handles 2 have a predetermined increase in capacitance, the weather has changed from fine weather to rainy weather. Therefore, the threshold value changing unit 12 changes the first threshold value TH1 from the fine weather threshold value A to the rainy weather threshold value B (step S3). On the other hand, if the electrostatic capacity has not increased by a predetermined value in at least two door handles 2, the threshold value changing unit 12 determines whether the electrostatic capacity has decreased by a predetermined value in at least two door handles 2. (Step S4). If the capacitance of the at least two door handles 2 has decreased by a predetermined amount, it is considered that the rain has changed to clear weather. Therefore, the threshold value changing unit 12 changes the first threshold value TH1 from the clear-weather threshold value B to the clear-sky threshold value A (step S5). Note that when the sky continues, the capacitance does not decrease by a predetermined amount, and the process does not proceed to step S5. On the other hand, if the capacitance does not decrease at least two door handles 2, the threshold value changing unit 12 maintains the first threshold value TH1 at the fine weather threshold A or at the rainy weather threshold B. Return to step S2. That is, when fine weather continues, the first threshold value TH1 is maintained as the fine weather threshold value A. When the rain continues, the first threshold TH1 is maintained as the rain threshold B.
The threshold value changing unit 12 repeats the processes of steps S2 to S5.

  As described above, according to the capacitance-type contact detection device 1, the threshold value changing unit 12 has a predetermined change in the capacitance of each capacitance sensor 3 in at least any two door handles 2. In addition, the first threshold value TH1 is changed. That is, the first threshold value TH1 is changed based on the change in the electrostatic capacity of the two or more door handles 2. When the weather changes, such as from clear weather to rain, from rainy weather to clear weather, it is considered that the same capacitance change occurs in the two or more door handles 2. Therefore, by changing the first threshold value TH1 based on the change in the capacitances of the two or more door handles 2, the threshold value changing unit 12 sets the first threshold value TH1 to an appropriate value according to each weather. It becomes possible to change. Thereby, while preventing erroneous contact detection due to raindrops adhering to the door handle 2, a capacitive contact detection device capable of accurately detecting contact of a bare hand to the door handle 2 and contact of a hand wearing a glove 1 can be obtained.

  The capacitive contact detection device 1 is used as a means for detecting contact of a user with the door handle 2 in a smart entry system for locking or unlocking the vehicle door 31 by contact with the door handle 2, for example. It is done.

  In the present embodiment, the first threshold value TH1 may be changed when the capacitances of all the capacitance sensors 3 change a predetermined amount.

  Moreover, you may change 1st Embodiment as follows. That is, the contact detection unit (not shown) measures the capacitance (C) in the capacitance sensor 3, and when the capacitance (C) becomes equal to or greater than the sixth threshold value TH6, the corresponding door. It may be determined that the user has touched the surface of the handle 2.

  Further, the first to fifth states are not limited to the above-described examples (sunny weather condition, rainy weather condition, light rain condition, medium rain condition, heavy rain condition), and can be changed as appropriate.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a diagram illustrating an arrangement example of door handles provided with sensor electrodes of the capacitive contact detection device according to the second embodiment. FIG. 12 is a top view showing a door handle provided with sensor electrodes of the capacitive contact detection device according to the second embodiment. FIG. 13 is a side view showing the door handle provided with the sensor electrode of the capacitive contact detection device according to the second embodiment. FIG. 14 is a diagram illustrating a capacitive contact detection device according to the second embodiment.

  The capacitive contact detection device 20 according to the second embodiment is a device that detects contact when rain comes in contact with the surface of the door handle 22 outside the vehicle. Although the material of the main body of the door handle 22 is not specifically limited, For example, it is a product made from a dielectric material. An example of the dielectric is synthetic resin. The capacitive contact detection device 20 detects that rain has come into contact with the upper surface of the door handle 22 and outputs a contact detection signal to the wiper control unit 23 and the like. The wiper control unit 23 drives the wiper 24 when a contact detection signal is input.

  The capacitance type contact detection device 20 includes a capacitance sensor 25, a detection unit 26, and a rainfall determination unit 27.

  The capacitance sensor 25 is configured by a sensor electrode 28 provided inside the door handle 22 forming a capacitor in cooperation with a conductor near the sensor electrode 28. The conductor is, for example, a door panel 29 to which the door handle 22 is attached or a user's finger. The sensor electrode 28 is provided on the upper surface of the door handle 22. The sensor electrode 28 is for detecting that rain has contacted the upper surface of the door handle 22. Capacitance sensors 25 are provided on at least two door handles 22, respectively. For example, as shown in FIGS. 11 and 14, the capacitance sensor 25 includes a door handle 22 for a driver side door, a door handle 22 for a passenger side door, a door handle 22 for a right rear seat side door, and It is provided in each door handle 22 of the left rear seat side door.

  The detection unit 26 detects the amount of change (ΔC) in the capacitance of the capacitance sensor 25. The method for measuring the amount of change in capacitance (ΔC) is not particularly limited.

  The rain judgment unit 27 judges that it is raining when the electrostatic capacity of each electrostatic capacity sensor 25 in the at least one of the two door handles 22 changes a predetermined amount.

  The rain determination unit 27 will be described in more detail. FIG. 15 is a diagram illustrating a relationship between a normal distribution (referred to as SS1) of the amount of change in capacitance (ΔC) when raindrops adhere and the threshold value TH of the amount of change in capacitance (ΔC).

  The operation of the rain judgment unit 27 will be specifically described. The detection unit 26 detects the amount of change in capacitance (ΔC) at a predetermined time period. When this period is converted into a frequency, for example, detection is performed at a frequency of about 1 MHz. The rain judgment unit 27 judges that it is raining when the increase of n periods (n is an arbitrary positive number) of each capacitance in the at least any two door handles 22 is equal to or greater than the threshold value TH. To do. The threshold value TH is set at, for example, one end of the normal distribution diagram SS1 (the side with the smaller capacitance) as shown in FIG.

FIG. 16 is a flowchart illustrating an example of the operation of the rain determination unit 27.
As shown in FIG. 16, first, the rain determination unit 27 determines whether or not the capacitance has increased by a predetermined amount in at least two door handles 22 based on the change in capacitance measured by the detection unit 26. Judgment is made (step S1). If the capacitance has increased by a predetermined amount in at least two door handles 22, the rain determination unit 27 determines that it is raining (step S2). On the other hand, if the capacitance has not increased by a predetermined amount in at least two door handles 22, the rain determination unit 27 determines that it is not raining (step S3). The rain judgment unit 27 repeats the processes of steps S1 to S3.

  As described above, according to the capacitance-type contact detection device 20, the rain determination unit 27 has a predetermined change in the capacitance of each capacitance sensor 25 in at least any two door handles 22. Judge that it is raining. That is, the rain determination unit 27 determines that it is raining based on the capacitance changes in the two or more door handles 22. When the weather changes, such as from clear weather to rain, from rainy weather to clear weather, it is considered that the same capacitance change occurs in the two or more door handles 22. Therefore, by determining that it is raining based on each capacitance change in the two or more door handles 22, the rain determining unit 27 can accurately detect the rain.

  The electrostatic capacitance type contact detection device 20 is used as a means for detecting a user's contact with the door handle 22 in a smart entry system for locking or unlocking the vehicle door 31 by contact with the door handle 22, for example. It is done.

  In the present embodiment, it may be determined that it is raining when the capacitances of all the capacitance sensors 25 change a predetermined amount.

  Moreover, you may change 2nd Embodiment as follows. That is, the detection unit (not shown) may detect the capacitance (C) in the capacitance sensor 25.

  The present invention is a capacitive contact detection device capable of accurately detecting a user's contact with a door handle while preventing erroneous contact detection due to raindrops adhering to the door handle, and accurately detecting rainfall. It can be used for an electrostatic capacity type contact detection device and the like.

The figure which shows the example of arrangement | positioning of the door handle provided with the sensor electrode of the electrostatic capacitance type contact detection apparatus which concerns on 1st Embodiment of this invention. The top view which shows the door handle provided with the sensor electrode of the electrostatic capacitance type contact detection apparatus which concerns on 1st Embodiment of this invention. The side view which shows the door handle provided with the sensor electrode of the electrostatic capacitance type touch detection apparatus which concerns on 1st Embodiment of this invention. The figure which shows the electrostatic capacitance type touch detection apparatus which concerns on 1st Embodiment of this invention. Normal distribution of change in capacitance when bare hands touch, change in capacitance when hands wearing gloves, and change in capacitance when raindrops are attached, and clear sky Showing an example of the relationship with the first threshold at the time Normal distribution of change in capacitance when bare hands touch, change in capacitance when hands wearing gloves, and change in capacitance when raindrops are attached Showing an example of the relationship with the first threshold at the time Normal distribution of change in capacitance when bare hands touch, change in capacitance when hands wearing gloves, and change in capacitance when raindrops are attached Showing an example of the relationship with the first threshold at the time Normal distribution of change in capacitance when bare hands touch, change in capacitance when hands wearing gloves, and change in capacitance when raindrops are attached Showing an example of the relationship with the first threshold at the time Normal distribution of change in capacitance when bare hands touch, change in capacitance when hands wearing gloves, and change in capacitance when raindrops are attached Showing an example of the relationship with the first threshold at the time The flowchart which shows an example of operation | movement of the threshold value change part in 1st Embodiment of this invention. The figure which shows the example of arrangement | positioning of the door handle provided with the sensor electrode of the electrostatic capacitance type touch detection apparatus which concerns on 2nd Embodiment of this invention. The top view which shows the door handle provided with the sensor electrode of the electrostatic capacitance type touch detection apparatus which concerns on 2nd Embodiment of this invention. The side view which shows the door handle provided with the sensor electrode of the electrostatic capacitance type contact detection apparatus which concerns on 2nd Embodiment of this invention. The figure which shows the electrostatic capacitance type touch detection apparatus which concerns on 2nd Embodiment of this invention. The figure which shows the relationship between the normal distribution of the amount of change in capacitance when raindrops are attached and the threshold value for the amount of change in capacitance The flowchart which shows an example of operation | movement of the rain judgment part in 2nd Embodiment of this invention. Normal distribution showing the amount of change in capacitance when a bare hand touches, the amount of change in capacitance when a hand wearing gloves touches, and the amount of change in capacitance when raindrops are attached, and the conventional distribution The figure which shows the relationship with the threshold value of the variation | change_quantity of the electrostatic capacitance of

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20 Capacitance type contact detection apparatus 2,22 Door handle 3,25 Capacitance sensor 4 Contact detection part 5,28 Sensor electrode 12 Threshold change part 26 Detection part 27 Rain judgment part

Claims (16)

A capacitive contact detection device that detects a user's contact with a door handle outside the vehicle,
A sensor electrode provided in the door handle is configured by forming a capacitor in cooperation with a conductor in the vicinity of the sensor electrode, and a capacitance sensor provided in each of the two or more door handles;
A contact detection unit that determines that the user has touched the surface of the door handle when the amount of change in capacitance in the capacitance sensor is equal to or greater than a first threshold;
A capacitance-type contact detection device comprising: a threshold value changing unit that changes the first threshold value when the capacitance of each capacitance sensor in the at least any two of the door handles changes a predetermined value. .   The said threshold value change part raises said 1st threshold value when the electrostatic capacitance of each said electrostatic capacitance sensor carries out the predetermined increase in at least any two said door handles, The said 1st threshold value is raised. The capacitance-type contact detection device described. The contact detection unit detects the capacitance at a predetermined time period,
When the increase in n cycles (n is an arbitrary positive number) of each of the capacitances in at least any two of the door handles is equal to or greater than a second threshold, the threshold value changing unit is configured to The capacitance type touch detection device according to claim 2, wherein the threshold value is changed from a value for the first state to a value for the second state. The contact detection unit detects the capacitance at a predetermined time period,
When the increase in n periods (n is an arbitrary positive number) of each of the capacitances in at least any two of the door handles is equal to or greater than a third threshold, the threshold value changing unit The threshold value is changed from the value for the third state to the value for the fourth state, or the value for the fourth state is changed to the value for the fifth state. Capacitance type contact detection device as described in 1.   The threshold value changing unit lowers the first threshold value when a change amount of capacitance of each of the capacitance sensors in the at least one of the two door handles has a predetermined decrease. Item 4. The capacitive contact detection device according to Item 1. The contact detection unit detects the capacitance at a predetermined time period,
When at least one of the two door handles has a state in which the decrease of each of the capacitances by n cycles (n is an arbitrary positive number) is less than a fourth threshold for a predetermined time, the threshold value changing unit is The capacitance type touch detection device according to claim 5, wherein the first threshold value is changed from a value for the second state to a value for the first state. The contact detection unit detects the capacitance at a predetermined time period,
When the state in which the decrease in n cycles (n is an arbitrary positive number) of each capacitance in at least any two of the door handles is less than a fifth threshold continues for a predetermined time, the threshold value changing unit is The first threshold value is changed from a value for the fourth state to a value for the third state, or a value for the fifth state is changed to a value for the fourth state. The electrostatic capacitance type contact detection device according to claim 5.   The capacitance type touch detection device according to claim 3 or 6, wherein the first state is a clear sky state, and the second state is a rainy weather state.   The static state according to claim 4 or 7, wherein the third state is a light rain state, the fourth state is a medium rain state, and the fifth state is a heavy rain state. Capacitive contact detection device. A capacitive contact detection device that detects a user's contact with a door handle outside the vehicle,
A sensor electrode provided in the door handle is configured by forming a capacitor in cooperation with a conductor near the sensor electrode, and a capacitance sensor provided in each of the two or more door handles;
A contact detection unit that determines that the user has touched the surface of the door handle when the capacitance in the capacitance sensor is equal to or greater than a sixth threshold;
A capacitance-type contact detection device, comprising: a threshold value changing unit that changes the sixth threshold value when the capacitance of each of the capacitance sensors has changed a predetermined value in at least any two of the door handles. .   A door handle provided with the capacitance type contact detection device according to claim 1. A smart entry system for locking or unlocking a vehicle door by touching a door handle,
A smart entry system comprising the door handle according to claim 11 as the door handle. A capacitive contact detection device for detecting rain contact with a door handle outside the vehicle,
A sensor electrode provided in the door handle is configured by forming a capacitor in cooperation with a conductor in the vicinity of the sensor electrode, and a capacitance sensor provided in each of the two or more door handles;
A detection unit for detecting a capacitance of the capacitance sensor or a change amount of the capacitance;
A capacitance type contact detection device comprising: a rain judgment unit that judges that it is raining when the capacitance of each of the capacitance sensors has changed a predetermined amount in at least any two of the door handles. . The detection unit detects the capacitance at a predetermined time period,
When at least one of the two door handles has an increase of n periods (n is an arbitrary positive number) of the capacitances equal to or greater than a threshold value, the rain determination unit determines that it is raining. The electrostatic capacitance type touch detection apparatus according to claim 13.   A door handle provided with the capacitive contact detection device according to claim 13 or 14. A smart entry system for locking or unlocking a vehicle door by touching a door handle,
A smart entry system comprising the door handle according to claim 15 as the door handle.

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