JP2010236316A - Catch preventing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely and surely prevent an object from being caught in an opening/closing part of a vehicle. <P>SOLUTION: The catch preventing device is arranged in an abutting end 3b of a window frame 3B abutting on a window 3A of the vehicle 1 when the window 3A is completely closed, and along the shape of the frame. The catch preventing device is provided with an electrostatic capacitance sensor part 10 detecting the object, and a circuit part 20. The electrostatic capacitance sensor part 10 is provided with a sensor electrode 11, a shield electrode 12 and an auxiliary electrode 13. Directional characteristics are set by using a first electrostatic capacitance value C1 detected only by the sensor electrode 11, and a second electrostatic capacitance value C2 detected by the sensor electrode 11 and the auxiliary electrode 13. A detection range Z is formed on a surface of the electrostatic capacitance sensor part 10 to detect hands 49 and fingers of a passenger and stop the closing operation before coming into contact with the window 3A etc. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an anti-pinch device for preventing an object from being caught in an opening / closing part such as a window part or a door part of a vehicle such as an automobile.

  As a device for preventing an object from being caught in an opening / closing part such as a window part or a door part of a vehicle such as an automobile, for example, a pinch detection sensor and a pinch prevention device (for example, Patent Document 1 (pages 4-6, 1-10) (See Figure)). This pinching prevention device detects displacement, distortion, and pressure change due to contact of an object by a pinching detection sensor made of a piezoelectric material disposed at an end of a window glass (window).

  And it is supposed that the opening / closing operation | movement of a window glass will be stopped based on that the output from a pinching detection sensor generate | occur | produces or changes with the contact of the detected object.

JP 2000-321150 A

  However, in the pinching prevention device disclosed in Patent Document 1 described above, the opening / closing operation of the window glass is stopped by the contact of the object with the pinching detection sensor. For this reason, the opening / closing operation of the window glass cannot be stopped prior to the contact, and there is a problem that it is difficult to control the opening / closing operation more safely and reliably.

  The present invention provides a pinching prevention device that can safely and reliably prevent an object from being caught in an opening / closing part such as a window part or a door part of a vehicle such as an automobile in order to eliminate the above-described problems caused by the prior art. The purpose is to do.

  In order to solve the above-described problems and achieve the object, an anti-pinch device according to the present invention includes an opening / closing member provided in a vehicle and a contacted member that contacts the opening / closing member when the opening / closing member is in a fully closed state. A sensor electrode arranged at the contact end, an auxiliary electrode provided in the vicinity of the sensor electrode, and at least the sensor electrode is connected to detect a capacitance value based on a capacitance from the connected electrode. A changeover switch capable of selectively switching between a detection circuit that performs the operation, a first connection state in which the auxiliary electrode is not connected to the detection circuit, and a second connection state in which the auxiliary electrode is connected to the detection circuit; A comparison value comparing the first capacitance value from the detection circuit in the first connection state with the second capacitance value from the detection circuit in the second connection state, and the first Or second And an opening / closing operation control means for determining whether or not the object is within a detection range on the sensor electrode and controlling the opening / closing operation of the opening / closing member based on the determination result. It is characterized by that.

  The change-over switch is configured to be able to open, connect to the ground, or to a predetermined potential, for example, when the auxiliary switch is in the first connection state.

  The shield switch further includes a shield drive circuit that applies a potential equivalent to the sensor electrode to the auxiliary electrode, and the changeover switch is configured to be able to connect the auxiliary electrode to the shield drive circuit, for example, in the first connection state. ing.

  In addition, a pinching prevention device according to the present invention includes an opening / closing member provided in a vehicle and a sensor electrode disposed at an abutting side end of one of a contacted member that contacts when the opening / closing member is in a fully closed state. , An auxiliary electrode provided in the vicinity of the sensor electrode, a detection circuit for detecting a capacitance value based on the capacitance from the sensor electrode, and a shield drive that applies a potential equivalent to the sensor electrode to the auxiliary electrode A changeover switch capable of selectively switching between a circuit, a first connection state in which the auxiliary electrode is connected to the shield drive circuit, and a second connection state in which the auxiliary electrode is open, grounded or connected to a predetermined potential A comparison value comparing the first capacitance value from the detection circuit in the first connection state and the second capacitance value from the detection circuit in the second connection state; and in front Opening / closing operation control for determining whether an object is within a detection range on the sensor electrode based on the first or second capacitance value and controlling the opening / closing operation of the opening / closing member based on the determination result Means.

  Further, the pinching prevention device according to the present invention includes an opening / closing member provided in a vehicle and a sensor electrode disposed at one contact side end of a contacted member with which the opening / closing member contacts when fully closed. An auxiliary electrode provided in the vicinity of the sensor electrode, a detection circuit for detecting a capacitance value based on a capacitance from the connected electrode, and a first connection for connecting the sensor electrode to the detection circuit A first changeover switch capable of selectively switching between a state and a second connection state in which the sensor electrode is not connected to the detection circuit; and when the sensor electrode is in the first connection state, A second changeover switch that is not connected to a detection circuit and is switchable to connect the auxiliary electrode to the detection circuit when the first changeover switch is in the second connection state; and In case A comparison value comparing the first capacitance value from the detection circuit and the second capacitance value from the detection circuit in the second connection state, and the first or second And an opening / closing operation control means for determining whether or not the object is within a detection range on the sensor electrode and controlling the opening / closing operation of the opening / closing member based on the determination result. It is characterized by that.

  The first changeover switch is configured to be able to open, connect to the ground or a predetermined potential of the sensor electrode in the second connection state, for example, and the second changeover switch is, for example, in the first connection state. Sometimes, the auxiliary electrode is open, grounded, or connectable to a predetermined potential.

  A shield driving circuit that applies a potential equivalent to the sensor electrode to the auxiliary electrode or a potential equivalent to the auxiliary electrode to the sensor electrode; and the first changeover switch is, for example, in the second connection state Sometimes the sensor electrode is configured to be connectable to the shield drive circuit, and the second changeover switch is configured to be able to connect the auxiliary electrode to the shield drive circuit, for example, in the first connection state. .

  A shield driving circuit for applying a potential equivalent to that of the sensor electrode to the auxiliary electrode is further provided, and the first changeover switch opens the auxiliary electrode, for example, is connected to ground or a predetermined potential in the second connection state. The second changeover switch is configured to be able to connect the auxiliary electrode to the shield drive circuit in the first connection state, for example.

  A shield driving circuit for applying a potential equivalent to that of the auxiliary electrode to the sensor electrode is further provided, and the first changeover switch is configured to be able to connect the auxiliary electrode to the shield driving circuit in the second connection state, for example. For example, the second changeover switch is configured to be able to open the auxiliary electrode, connect to the ground, or to a predetermined potential in the first connection state.

  The auxiliary electrode is disposed, for example, so as to surround the sensor electrode.

  The opening / closing operation control means stops the opening / closing operation of the opening / closing member, for example, when it is determined that the object is within the detection range on the sensor electrode.

  The opening / closing member is, for example, at least one of a vehicle window and a door.

  ADVANTAGE OF THE INVENTION According to this invention, the pinching prevention apparatus which can prevent the pinching of the object to opening / closing parts, such as a window part and a door part of a vehicle, safely and reliably can be provided.

It is explanatory drawing which shows the example of the whole structure of the pinching prevention apparatus concerning one Embodiment of this invention. It is AA sectional drawing of FIG. It is explanatory drawing which shows the example of the whole structure of the electrostatic capacitance sensor part and circuit part of the same pinching prevention apparatus. It is explanatory drawing for demonstrating the operation | movement concept at the time of the detection operation | movement of the same pinch prevention device. It is explanatory drawing for demonstrating the relationship between the detection target object and the electric force line at the time of the detection operation | movement of the same pinch prevention apparatus. It is explanatory drawing for demonstrating the operation | movement concept at the time of the detection operation | movement of the same pinch prevention device. It is a flowchart which shows the example of the closing operation control processing procedure by the pinching prevention device. It is explanatory drawing which shows the other example of the whole structure of the electrostatic capacitance sensor part of the same pinching prevention apparatus, and a circuit part. It is explanatory drawing which shows the example of the whole structure of the electrostatic capacitance sensor part and circuit part of the pinching prevention apparatus concerning other embodiment of this invention. It is a flowchart which shows the example of the closing operation control processing procedure by the pinching prevention device. It is explanatory drawing which shows the other example of the whole structure of the electrostatic capacitance sensor part of the same pinching prevention apparatus, and a circuit part. It is explanatory drawing which shows the example of the whole structure of the electrostatic capacitance sensor part and circuit part of the pinching prevention apparatus concerning further another embodiment of this invention. It is explanatory drawing for demonstrating the operation | movement concept at the time of the detection operation | movement of the same pinch prevention device. It is explanatory drawing for demonstrating the relationship between the detection target object and electric force line at the time of 1st detection operation | movement of the said pinching prevention apparatus. It is explanatory drawing for demonstrating the relationship between the detection target object and electric force line at the time of 1st detection operation | movement of the said pinching prevention apparatus. It is explanatory drawing for demonstrating the relationship between the detection target object and electric force line at the time of 1st detection operation | movement of the said pinching prevention apparatus. It is explanatory drawing for demonstrating the relationship between the detection target object and electric force line at the time of 2nd detection operation | movement of the said pinching prevention apparatus. It is explanatory drawing for demonstrating the relationship between the detection target object and electric force line at the time of 2nd detection operation | movement of the said pinching prevention apparatus. It is explanatory drawing for demonstrating the relationship between the detection target object and electric force line at the time of 2nd detection operation | movement of the said pinching prevention apparatus. It is explanatory drawing which shows the example of the whole structure of the electrostatic capacitance sensor part and circuit part of the pinching prevention apparatus concerning further another embodiment of this invention. It is explanatory drawing which shows the other example of the whole structure of the electrostatic capacitance sensor part of the same pinching prevention apparatus, and a circuit part.

  Hereinafter, preferred embodiments of a pinching prevention device according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is an explanatory diagram showing an example of the overall configuration of an anti-pinch device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. It is explanatory drawing which shows the example of the whole structure of a circuit part. As shown in FIG. 1, the pinching prevention device according to the present embodiment is a window frame that is one of the members to be contacted, for example, when a window 3A that is one of the opening / closing members provided in the vehicle is in a fully closed state. The capacitive sensor unit 10 is disposed along the frame shape in the abutting side end 3b of the unit 3B and detects an object (for example, a hand or a finger).

  Further, the pinching prevention device determines whether or not the object is within the detection range Z on the capacitance sensor unit 10 based on the output from the capacitance sensor unit 10, and opens and closes the window 3 </ b> A. The circuit unit 20 is configured to control the above. The control signal for the opening / closing operation of the window 3A output by the circuit unit 20 is output to the motor 30 that actually drives the window 3A.

  As shown in FIG. 2, in this example, one capacitance sensor unit 10 is arranged along the frame shape in the contact side end 3b, but the surface of the contact side end 3b. One may be arranged along the frame shape. In any of these cases, for example, a plurality of capacitance sensor units 10 may be arranged along the frame shape at predetermined intervals. Furthermore, the capacitance sensor unit 10 may be disposed at the contact side end 3a of the window 3A.

  As shown in FIG. 3, the capacitance sensor unit 10 is configured such that a detection range Z exists in the detection region on the detection surface side, and the sensor electrode 11 formed in a rectangular band shape, and the back side of the sensor electrode 11 And the auxiliary electrode 13 formed on the same plane as the sensor electrode 11 and formed in a hollow long frame shape surrounding the sensor electrode 11.

  The sensor electrode 11 and the auxiliary electrode 13 are disposed so as to be insulated from each other. The shield electrode 12 is preferably larger than the sensor electrode 11 in order to reduce the sensor sensitivity on the back side.

  The sensor electrode 11 detects an object in the detection range Z of the detection area on the detection surface side. The shield electrode 12 shields them from being detected on the back side of the sensor electrode 11. The auxiliary electrode 13 is used to vary the equal capacitance line (surface) on the detection surface side of the sensor electrode 11 so that the capacitance sensor unit 10 has directivity. In addition, the shield electrode 12 may be provided in the outer peripheral side of the auxiliary electrode 13 together with the aspect mentioned above, for example.

  The circuit unit 20 is connected to the capacitance sensor unit 10 and includes, for example, a CV conversion circuit 21 directly connected to the sensor electrode 11, an A / D converter 22, and a CPU 23. Here, a shield drive circuit 12 is further provided, and a changeover switch SW for switching the connection of the auxiliary electrode 13 between the CV conversion circuit 21 and the shield drive circuit 24 is provided.

  The CV conversion circuit 21 converts a capacitance detected by the sensor electrode 11 or the sensor electrode 11 and the auxiliary electrode 13 into a voltage (Voltage). The A / D converter 22 converts an analog signal indicating a voltage from the CV conversion circuit 21 into a digital signal.

  The CPU 23 controls the entire anti-pinch device and controls the changeover switch SW, determines the detection (presence / absence) of a detection object (such as a hand or a finger) within the detection range Z of the detection area, and the determination result. And a control signal is output to the motor 30 that drives the window 3A. The shield drive circuit 24 drives, for example, the shield electrode 12 and the auxiliary electrode 13 to the same potential as the sensor electrode 11.

  The circuit unit 20 includes a storage unit (not shown) such as a RAM used as a temporary storage area of the CPU 23 or a ROM for storing data. In addition, the capacitance sensor unit 10 is formed on a substrate (not shown), for example. As this board | substrate, any board | substrate of a flexible printed circuit board, a rigid board | substrate, and a rigid flexible board | substrate is employable, for example.

  Furthermore, the circuit unit 20 may be mounted and integrally provided on the same surface side or the back surface side of the substrate on which the capacitance sensor unit 10 is formed. In this case, a plurality of circuit units 20 may be provided so as to correspond to the number of capacitance sensor units 10.

  The sensor electrode 11, the shield electrode 12, and the auxiliary electrode 13 are substrates made of an insulator such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyamide (PA), glass epoxy resin, or ceramic. It can be composed of copper, a copper alloy, a metal member (conductive material) such as aluminum or iron, an electric wire, or the like patterned on top.

  Depending on the arrangement mode of the capacitance sensor unit 10 (for example, when it is arranged on the window 3A side), it may be necessary to arrange the capacitance sensor part 10 so that it is not conspicuous to the passenger. In such a case, the substrate may be formed of a transparent panel or film, and the electrodes 11 to 13 may be transparent electrodes. The transparent electrode can be composed of, for example, tin-doped indium oxide (ITO) or a conductive polymer. As the conductive polymer, for example, PEDOT / PSS (polyethylene dioxythiophene / polystyrene sulfonic acid), PEDOT / TsO (polyethylene dioxythiophene / toluene sulfonate), or the like can be used.

  Next, an object detection operation of the anti-pinch device configured as described above will be described. First, an operation (operation 1) when the changeover switch SW is connected to the shield drive circuit 24 side under the control of the CPU 23 will be described. In the case of this operation 1, the connection state between the sensor electrode 11, the shield electrode 12 and the auxiliary electrode 13 of the capacitance sensor unit 10 and the circuit unit 20 is as shown in FIG.

  That is, only the sensor electrode 11 is connected to the CV conversion circuit 21, and the shield electrode 12 and the auxiliary electrode 13 are connected to the shield drive circuit 24. The capacitance C is detected by the CV conversion circuit 21. At this time, the back surface side of the sensor electrode 11 is covered with the shield electrode 12 connected to the shield drive circuit 24. For this reason, the sensor sensitivity on the back surface side of the sensor electrode 11 is almost equal, and this is also the case with the operation 2 described later.

  Further, both detection objects A and B are at substantially the same distance from the sensor electrode 11. However, due to the influence of the auxiliary electrode 13 connected to the shield drive circuit 24, the above-described equal capacitance line (surface) M is in a state as shown in FIG. Lower than the sensor sensitivity to.

  In this case, as shown in FIG. 5A, the electric lines of force P1 from the sensor electrode 11 with respect to the detection object A existing near the center of the sensor electrode 11 are the electric lines of force P2 from the auxiliary electrode 13 (shield). ) Is small. However, as shown in FIG. 5B, the electric lines of force P <b> 1 from the sensor electrode 11 to the detection target B existing outside the sensor electrode 11 are the electric lines of force P <b> 2 (shield) from the auxiliary electrode 13. It can be said that it is easily affected.

  For this reason, in the operation 1, both the detection objects A and B exist at the same distance from the sensor electrode 11, but the capacitance value detected by the CV conversion circuit 21 is the detection object of the detection object A. It becomes larger than the object B. The first capacitance value C1 detected during such operation 1 is stored in the storage unit by the CPU 23.

  In the case of this operation 1, by connecting the auxiliary electrode 13 to the shield drive circuit 24, the sensor at the electrode end (end on the auxiliary electrode 13 side) of the sensor electrode 11 with respect to the sensor sensitivity at the center of the sensor electrode 11 is detected. Sensitivity can be lowered. Thereby, it is possible to give the capacitance sensor unit 10 a slight directivity.

  However, in this operation 1, the sensor sensitivity of the electrode end of the sensor electrode 11 is only slightly reduced. Therefore, for example, the capacitance value of the detection object C (see FIG. 4) located closer to the sensor electrode 11 than the detection object B shown in FIG. 5B is equal to the capacitance value of the detection object A. It becomes almost equal. At this time, the equal capacitance line (surface) M is in a state as shown in FIG. For this reason, the difference between the detection objects A and C cannot be determined, and it must be said that this is a state in which a stronger directivity cannot be provided.

  Next, an operation (operation 2) when the changeover switch SW is connected to the CV conversion circuit 21 side under the control of the CPU 23 will be described. In the case of this operation 2, the connection state between the sensor electrode 11, the shield electrode 12, and the auxiliary electrode 13 of the first and second capacitance sensor units 10 and 20 is as shown in FIG.

  That is, since the sensor electrode 11 and the auxiliary electrode 13 are connected to the CV conversion circuit 21, the capacitance between the detection objects A and B is changed by the CV conversion circuit 21 by the sensor electrode 11 and the auxiliary electrode 13. Detected. At this time, as described above, the sensor sensitivity on the back surface side of the sensor electrode 11 is almost equal, but the equivalent capacitance line (surface) M on the detection surface side (front surface side) of the sensor electrode 11 is in the state shown in FIG. Thus, it can be said that there is no directivity in the range of 180 ° on the detection surface side.

  For this reason, in the operation 2, substantially the same capacitance value is detected for both detection objects A and B existing at substantially the same distance from the sensor electrode 11. Then, the second capacitance value C2 detected during such operation 2 is stored in the storage means by the CPU 23 in the same manner as the first capacitance value C1.

  As described above, the operation 1 and the operation 2 described above can vary the equicapacitance line (surface) M on the detection surface side by the sensor electrode 11. Thus, the first capacitance value C1 detected when there is a slight directivity on the detection surface side of the sensor electrode 11 and the second capacitance detected when there is no directivity on the detection surface side of the sensor electrode 11. Is obtained.

  Thereafter, in the pinching prevention device of this example, the following operation is performed. First, the first capacitance value C1 stored in the storage means by the CPU 23 is compared with the second capacitance value C2. For example, in the case of the operation 2 described above, since the capacitance values detected from both the detection objects A and B are substantially the same value, the detection objects A and B are at an approximately equal distance from the sensor electrode 11. It turns out that there is.

  Next, in the case of the operation 1, since the electrostatic capacitance value of the detection target B is smaller than the detection target A, the detection target B should be outside the detection electrode A with respect to the sensor electrode 11. Becomes clear. Based on these considerations, the CPU 23 compares the second capacitance value C2 with the first capacitance value C1 to determine how much the detection target is outside the central portion of the sensor electrode 11. (That is, whether or not the detection target is within a predetermined range including at least a region facing the detection surface of the sensor electrode 11 (hereinafter, may be abbreviated as “in the detection range”)). ) Can be determined.

  According to the anti-pinch device configured and operated as described above, as shown in FIG. 1, for example, an electrostatic capacitance disposed by the electrostatic capacitance sensor unit 10 in the abutting side end 3b of the window frame portion 3B. It can be determined whether or not there is an object (such as a hand or a finger) within the detection range Z formed on the sensor unit 10 (sensor electrode 11). The detection range Z is determined by the set directivity. For this reason, for example, even if there is an object outside the detection range Z in the vicinity of the contact side end 3b of the window frame portion 3B, whether or not there is an object within the detection range Z without detecting this object. The detection range Z is set to an area on the sensor electrode 11 so that it can be accurately determined.

  Based on the determination result, for example, when an object is detected, a control signal for stopping the opening / closing operation of the window 3 </ b> A is output to the motor 30. The motor 30 immediately stops the opening / closing operation of the window 3A based on the control signal. In this way, it is possible to prevent the object from being caught between the window 3A and the window frame 3B safely and surely before the object actually contacts the window 3A or the window frame 3B. . Here, the closing operation control processing of the window 3A as the pinching prevention processing will be described.

  FIG. 7 is a flowchart showing an example of a procedure for controlling the closing operation of the window 3A by the pinch prevention device. In the following, it is assumed that the same reference numerals are assigned to portions that overlap with the portions that have already been described, and descriptions thereof are omitted. As shown in FIG. 7, first, the pinching prevention device waits until the closing operation is started, for example, when the closing operation switch of the window opening / closing device of the vehicle 1 is pressed (N in Step S101). When the closing operation is started (Y in step S101), the connection state of the auxiliary electrode 13 by the change-over switch SW is switched to the first and second connection states described above under the control of the CPU 23 of the circuit unit 20.

  Thus, the capacitance value (first and second capacitance values C1, C2) is detected in the capacitance sensor unit 10 (step S102), and these are compared to calculate a comparison value (step S103). .

  Then, based on the first capacitance value C1 or the second capacitance value C2, it is determined whether or not a detection target (hand, finger, etc.) is close to the sensor electrode 11 (step S104). ). At the same time, it is determined whether or not the calculated comparison value is greater than or equal to a predetermined threshold value set in advance (or less than a predetermined threshold value or less than a predetermined threshold value, for example) (step S105).

  When it is determined that a hand or a finger is in proximity (Y in step S104) and the comparison value is determined to be equal to or greater than a predetermined threshold (Y in step S105), the hand or finger is detected. (Step S106), a control signal is output to the motor 30, and the closing operation of the window 3A is stopped (step S107).

  If the closing operation of the window 3A is controlled using the determination result determined as described above, the window 3A is brought into contact with a hand or a finger at a position between the window 3A and the window frame portion 3B as described above. Can be stopped. For this reason, it is possible to prevent the detection object from being caught between the window 3A and the window frame 3B safely and reliably.

  Thereafter, for example, it is determined whether or not a stop release condition is satisfied such that a hand or a finger is not continuously detected for a predetermined time (step S108), and the closing operation is stopped until the stop release condition is satisfied (N in step S108). (Step S107) When the stop cancellation condition is satisfied (Y in Step S108), the closing operation of the window 3A is resumed.

  On the other hand, when it is determined that the hand or finger is not in proximity (N in step S104), or when it is determined that the comparison value is not equal to or greater than the predetermined threshold (N in step S105), the hand or finger Are not detected (step S109), and the closing operation of the window 3A is still performed. Then, for example, it is determined whether or not the closing operation is to be terminated by using the closing of the closing operation switch of the window opening / closing device of the vehicle 1 as a trigger (step S110).

  When it is determined that the closing operation is to be ended (Y in step S110), a series of closing operation control processing according to this flowchart is ended. When it is determined that the closing operation is not completed (N in Step S110), the process proceeds to Step S102, and the first and second capacitance values C1 and C2 of the capacitance sensor unit 10 are detected. The subsequent processing is repeated.

  Specifically, for example, in step S104, when the first capacitance value C1 is larger than the predetermined threshold value Th1, it can be determined that a hand, a finger, or the like has approached the sensor electrode 11. Set it. At this time, for example, in step S105, the comparison value α or the comparison value β calculated by a calculation formula such as the comparison value α = (a × C1) − (b × C2) or the comparison value β = d × C1 / C2. Is smaller than the arbitrary threshold value Th2 as a predetermined threshold value set in advance, it is set so that it can be determined that it is outside the detection range Z.

  Only when the hand or finger is close (Y in step S104) and the comparison value is equal to or greater than the threshold Th2 (Y in step S105), the hand or finger is determined to be detected. (Step S106). Thus, according to the pinching prevention device of the present example, on the surface of the capacitance sensor unit 10 (on the sensor electrode 11) disposed in the abutting side end 3b of the window frame 3B of the vehicle 1. The proximity of a hand or a finger to the detection range Z can be detected accurately and reliably to prevent pinching.

  Note that the coefficients a, b, and c in the comparison values α and β, the calculation formulas of the comparison values α and β, the values of the threshold values Th1 and Th2, and the like may be as follows. That is, these change depending on factors such as the sensor shape of the capacitance sensor unit 10, the surrounding environment of the installation, and the characteristics of the detection target. For this reason, what is necessary is just to set it sequentially, taking a profile, when these each factor is decided.

  In the above-described example, the proximity of an object such as a hand or a finger is determined by comparison using a value obtained by dividing the first capacitance value C1 by the second capacitance value C2. In addition, for example, the first capacitance value C1 is compared using a value obtained by dividing the first capacitance value C1 by the sum of the first capacitance value C1 and the second capacitance value C2, or other calculations are performed. You may make it determine proximity | contact using a method.

  Thus, according to the pinching prevention device of this example, for example, when the threshold Th2 is large, the intensity of the directivity of the sensor sensitivity of the capacitance sensor unit 10 can be high, and when the threshold Th2 is small, it can be low. Therefore, it is possible to arbitrarily set the detection range Z on the surface of the capacitance sensor unit 10 disposed in the contact side end portion 3b of the window frame portion 3B by arbitrarily adjusting the directivity. Thus, it is possible to reliably and accurately detect a hand or a finger in the detection range Z having the directivity of.

  The CV conversion circuit 21 of the circuit unit 20 described above uses, for example, a known timer IC in which the duty ratio of the output pulse is changed by a resistor and a capacitor, but is not limited to this.

  That is, for example, a method in which a sine wave is applied to directly measure an impedance from a voltage change or a current value due to a capacitance value, a method in which an oscillation circuit is configured including a capacitance value to be measured, and an oscillation frequency is measured, RC A charge / discharge circuit is configured to measure the charge / discharge time, a charge charged with a known voltage is transferred to a known capacity and the voltage is measured, or an unknown capacity is charged with a known voltage and the charge is charged. There is a method to measure the number of times until the known capacity is charged to a predetermined voltage by moving it to a known capacity multiple times, setting a threshold value for the detected capacitance value, or a waveform of the capacitance May be processed as a trigger when the corresponding capacitance waveform is obtained.

  In addition, it is assumed that the CV conversion circuit 21 of the circuit unit 20 converts the electrostatic capacity into a voltage, but it is only necessary to convert the data into data that can be handled electrically or as software. For example, the electrostatic capacity is converted into a pulse width. It may be converted or directly converted into a digital value.

  Furthermore, in the pinching prevention device described above, the sensor electrode 11, the shield electrode 12, and the auxiliary electrode 13 of the capacitance sensor unit 10 are arranged in the contact side end portion 3 b of the window frame portion 3 </ b> B of the vehicle 1. An example in which detection of an object such as a hand or a finger is determined by comparing the first capacitance value C1 of only the sensor electrode 11 with the second capacitance value C2 of the sensor electrode 11 and the auxiliary electrode 13 For example, the following may be used.

  FIG. 8 is an explanatory diagram illustrating another example of the overall configuration of the capacitance sensor unit and the circuit unit of the pinch prevention device. The pinching prevention device of this example has a configuration in which a dummy sensor electrode (dummy electrode) 19 is arranged in addition to the sensor electrode 11, and the CV conversion circuit 21 of the circuit unit 20 is configured to perform a differential operation. ing.

  Specifically, as shown in FIG. 8, for example, the sensor electrode 11 is connected to the positive input end of the differential amplifier circuit, and the dummy electrode 19 is connected to the negative input end of the differential amplifier circuit. The value of the capacitance Cb is subtracted. The output value is compared with a threshold value by a comparator or the like to detect the hand 49 or the finger.

  As an operation of such a CV conversion circuit 21, for example, when the switch S1 is open (OFF), the switch S2 is grounded (GND), and the switch S3 is closed (ON), the switch S3 is operated. Open (OFF), switch S2 is switched to Vr, and switch S1 is connected to the inverting input of the operational amplifier. Then, the capacitances Ca and Cf are charged with CaVr, and the capacitances Cb and Cf are charged with CbVr.

  Next, after the switch S1 is opened (OFF) and the switch S2 is grounded (GND), the output voltage V when the switch S1 is grounded (GND) is measured. The voltage at this time is V / Vr = {(Cf + Ca) / Cf} − {(Cf + Cb) / Cf}, and a voltage corresponding to the ratio between the capacitance Ca and the capacitance Cb is output.

  As described above, the CV conversion circuit 21 is configured to perform a differential operation (differential circuit), so that the temperature characteristics of the circuit can be offset and common mode noise can be reduced. At this time, for example, the dummy electrode 19 is connected to the negative input end of the differential amplifier circuit. If the dummy electrode 19 is capacitively coupled to the hand 49 or the finger, the sensitivity of the sensor itself is lowered.

  Therefore, the area of the dummy electrode 19 is made sufficiently small with respect to the sensor electrode 11, or another shield electrode 47 having the same potential is provided between the dummy electrode 19 and the hand 49, the finger, etc. It is necessary to reduce the capacitive coupling with the finger or the finger.

  In the shield drive circuit 24 described above, when the duty ratio changes according to the capacitance C, the output waveform of the sensor electrode 11 changes depending on the measured capacitance. To do. For this reason, a 1 × amplifier circuit may be configured with a voltage follower such as an operational amplifier or a source follower such as an FET, and the output of the sensor electrode 11 may be input and the output connected to the shield electrode 12 or the like. .

  Further, when the CV conversion circuit 21 operates differentially, the shield drive circuit 24 has a rectangular waveform with the voltage Vr and GND as the output waveform of the sensor electrode 11 and the frequency becomes the switching frequency of the switch. Therefore, since it does not vary depending on the capacitance value, the non-inverting input of the operational amplifier shown in FIG. 8 may be connected to the shield electrode 12 or the like. However, when a driving current is required, a rectangular wave of Vr and GND may be separately generated through an operational amplifier with a high output current.

  Furthermore, in the above-described embodiment, the sensor electrode 11 is connected to the CV conversion circuit 21, the shield electrode 12 is connected to the shield drive circuit 24, and the auxiliary electrode 13 is connected to the shield electrode 24 or C via the changeover switch SW. It was configured to be connected to the −V conversion circuit 21. In addition, for example, when the CV conversion circuit 21 operates differentially, the sensor electrode 11 is connected to the negative side input end shown in FIG. 8, the shield electrode 12 is connected to the shield drive circuit 24, and You may comprise so that the auxiliary electrode 13 may each be connected to a plus side input end.

  In this case, in the operation 2 described above, the auxiliary electrode 13 is connected to the sensor electrode 11 and there is almost no directivity. However, in the operation 1 described above, the capacitance coupling value between the auxiliary electrode 13 and the hand 49 or the finger is subtracted from the capacitance value of the sensor electrode 11, and as a result, it has a loose directivity. It becomes. Similar to the case described above, the same effect can be obtained by comparing the detection values in the operation 1 and the operation 2.

  Furthermore, in the above-described embodiment, the auxiliary switch 13 is configured to be connected to the shield drive circuit 24 during the operation 1 and connectable to the CV conversion circuit 21 during the operation 2 by the changeover switch SW. In the case of 1 and operation 2, the equal capacitance line (surface) M is made variable. In addition, the auxiliary electrode 13 is configured to be connected to the shield drive circuit 24 at the time of operation 1, for example, to be open, grounded, or connectable to a predetermined potential at the time of operation 2, or for example at the time of operation 1 Can be connected to an open, grounded or predetermined potential, and can be connected to the CV conversion circuit 21 in the operation 2 to obtain the same effect. In this way, the auxiliary electrode 13 is connected to the open state by the changeover switch SW, or connected to the ground or other potential (including a potential equivalent to the ground, pulse, charging voltage, sine wave, etc.). May be.

  Note that the change-over switch SW only needs to have a structure capable of switching electrical connection. For example, an electronic circuit switch such as an FET or a photo MOS relay or a mechanical switch such as a contact switch can be employed. In addition to the above-described shape, the sensor electrode 11 may have various shapes such as a circle, an ellipse, a rectangle, and a polygon. For example, when the back surface side of the sensor electrode 11 is also within the detection range Z. If the shield electrode 12 is not provided.

  The auxiliary electrode 13 is arranged so as to surround the entire periphery of the sensor electrode 11. However, as long as the detection range Z can be set, the auxiliary electrode 13 is in a state of surrounding a part or arranged in a part adjacent to the sensor electrode 11. Or you may. Further, for example, when the sensor electrode 11 is surrounded, the sensor electrode 11 may be arranged concentrically (the center is the same).

  Next, a capacitance sensor unit and a circuit unit of an anti-pinch device according to another embodiment of the present invention will be described with reference to FIGS. In the pinching prevention device according to the above-described embodiment, the output from the CV conversion circuit 21 of the circuit unit 20 is the second capacitance value indicating the capacitance detected by the sensor electrode 11 and the auxiliary electrode 13. Either C2 or the first capacitance value C1 indicating the capacitance detected only by the sensor electrode 11.

  For this reason, the capacitance value detected by the structure around the installation place of the sensor electrode 11 (including the capacitance sensor unit 10) may differ. In such a case, the comparison result obtained by comparing the first and second capacitance values C1 and C2 may change depending on the structure around the place where the sensor electrode 11 is installed. In order to avoid such a situation, the internal configuration of the circuit unit 20 may be further set as follows, for example.

  FIG. 9 is an explanatory view showing an example of the overall configuration of the capacitance sensor unit 10 and the circuit unit 20 of the pinching prevention device according to another embodiment of the present invention, and FIG. 10 is a closing operation of the window 3A by the pinching prevention device. FIG. 11 is an explanatory diagram showing another example of the entire configuration of the capacitance sensor unit 10 and the circuit unit 20 of the pinching prevention device. In the following description, parts that are the same as those already described are denoted by the same reference numerals, description thereof is omitted, and parts not particularly related to the present invention may not be specified.

  As shown in FIG. 9, in the circuit unit 20 of this example, in addition to the CV conversion circuit 21 and the shield drive circuit 24 described above, a determination circuit 25 made of, for example, a CPU, a hand 49, a finger, and the like approach each other. An initial capacity storage device 26 that stores an electrostatic capacity value (initial capacity) when not, a switch control circuit 27 that controls the switching operation of the selector switch SW, and a buffer 28.

  As an outline of the object detection operation of the anti-pinch device having the circuit unit 20 configured as described above, for example, the capacitance sensor unit 10 is similarly placed in the abutting side end 3b of the window frame 3B of the vehicle 1. Deploy. Thereafter, the capacitance value (initial capacitance) in the operation 1 and the operation 2 when the hand 49 or the finger is not approaching the capacitance sensor unit 10 is switched by the switch control circuit 27 under the control of the switch SW. Detect each.

  Then, these values are stored in the initial capacity storage device 26, and the initial capacity is determined from the first and second electrostatic capacitance values C1 and C2 in the actual operations 1 and 2 described above in the determination circuit 25. These initial capacities stored in the storage device 26 are subtracted and compared. Based on the comparison result thus obtained, it is determined whether or not the hand 49 or the finger is within the detection range Z on the sensor electrode 11.

  More specifically, the initial capacity is stored as the first initial capacity when the changeover switch SW is connected to the shield drive circuit 24 side by the control of the switch control circuit 27 as the first initial capacity. It is stored in the device 26. In addition, the operation at the time of the operation 2 when the changeover switch SW is connected to the CV conversion circuit 21 side is stored in the initial capacity storage device 26 as the second initial capacity.

  Then, in the actual operation 1, the determination circuit 25 subtracts the first initial capacity stored in the initial capacity storage device 26 from the detected first capacitance value C1 and performs the first detection. Value (detection value 1). In the actual operation 2, the second detection value (detection value 2) is obtained by subtracting the second initial capacitance stored in the initial capacitance storage device 26 from the detected second capacitance value C2. ).

  That is, as shown in FIG. 10, first, the pinching prevention device waits until the closing operation is triggered by the depression of the closing operation switch of the window opening / closing device of the vehicle 1 (step S201). N) When the closing operation is started (Y in step S201), the first detection value and the second detection value as described above are calculated (step S202), and these are compared to calculate a comparison value. (Step S203).

  Thereafter, based on the first or second detection value, it is determined whether or not the hand 49 or the finger is in proximity (step S204). At the same time, whether the comparison value of the first detection value and the second detection value is, for example, a predetermined threshold value or more (or less than a predetermined threshold value or less than a predetermined threshold value). It is determined whether or not (step S205).

  That is, here, it is determined whether or not the hand 49 or the finger is in the detection range Z based on the detection values 1 and 2 and the comparison result. Note that the detection value 2 at the time of the operation 2 in which the sensor electrode 11 and the auxiliary electrode 13 are connected to the CV conversion circuit 21 is a detection value in a state in which the sensor sensitivity has no directivity. The output depends on the approach to the capacitance sensor unit 10 such as a finger.

  When it is determined that the hand 49 or the finger is close (Y in step S204) and the comparison value is determined to be equal to or greater than a predetermined threshold (Y in step S205), the hand 49 or the finger Is detected (step S206), and the closing operation is stopped as described above (step S207). Thereafter, for example, it is determined whether or not a stop release condition is satisfied such that a hand 49 or a finger is not detected continuously for a predetermined time (step S208), and the closing operation is stopped until the stop release condition is satisfied (N in step S208). When the stop cancellation condition is satisfied (Y in step S208), the closing operation of the window 3A is resumed.

  If it is determined that the hand 49 or the finger is close (Y in step S204), but the comparison value is determined not to be equal to or greater than the predetermined threshold (N in step S205), the hand 49 or the finger Is determined not to be detected (step S209). Then, for example, a non-detection signal A (for example, a high impedance, a predetermined potential, etc.) that is a disable signal indicating that the hand 49 or the finger does not exist within the detection range Z when the directivity is given is determined and output. Output as.

  Further, for example, based on the first or second detection value (or the first or second capacitance value C1, C2), it is determined whether or not the hand 49 or the finger is in proximity (step S204). When it is determined that the hand 49 or the finger is not in proximity (N in Step S204), the process proceeds to Step S209 and determines that these are not detected. Then, for example, a non-detection signal B (a signal different from the non-detection signal A) that is a disable signal indicating that the hand 49 or the finger is not within the detection range Z on the sensor electrode 11 is output as a determination output.

  After that, for example, it is determined whether or not the closing operation is terminated by using the trigger of the pressing of the closing operation switch of the window opening / closing device of the vehicle 1 as a trigger (step S210). If it is determined that the closing operation is to be ended (Y in step S210), the series of closing operation control processing according to this flowchart is ended. If it is determined that the closing operation is not finished (N in step S210), the process proceeds to step S202, the first and second detection values are calculated, and the subsequent processing is repeated.

  In this manner, by using the output of the determination circuit 25 as an enable signal or a disable signal, for example, according to the determination result, when the hand 49 or the finger is within the detection range Z on the sensor electrode 11, the enable signal is buffered. And the detection value 1 is output from the buffer 28. When the hand 49 or the finger is not within the detection range Z on the sensor electrode 11, the determination output is fixed to a predetermined voltage such as a ground voltage or a reference voltage as a disable signal, or becomes a high impedance output. .

  When the hand 49 or the finger is within the detection range Z on the sensor electrode 11, in addition to the detection value 1, the detection value 2 and the first or second capacitance values C1 and C2 are output. May be. The detection value 1, the detection value 2, and the first and second capacitance values C1 and C2 indicate values corresponding to the distance to the sensor electrode 11 such as the hand 49 or the finger.

  Thus, according to the circuit unit 20 configured as described above, when the hand 49 or a finger is within the detection range Z, a detection value corresponding to the distance is output, and when the hand 49 or finger is not within the detection range Z, a predetermined voltage is output. And so on. Therefore, it is possible to determine whether or not there is a hand 49 or a finger in the detection range Z, and if so, how long it is. That is, it is possible to increase the intensity of the directivity of the sensor sensitivity of the capacitance sensor unit 10 or to set the directivity in more detail.

  Further, as another example of a method for avoiding dependence on the structure around the place where the capacitance sensor unit 10 is installed, these can be held by adjusting the reference voltage as follows. It becomes. That is, as shown in FIG. 11, the circuit unit 20 of this example includes a reference voltage adjustment circuit 40 and a subtraction circuit 31 in addition to the CV conversion circuit 21 and the shield drive circuit 24.

  The reference voltage adjustment circuit 40 adjusts the output of the CV conversion circuit 21 to the reference potential when measuring the initial capacitances of the first and second initial capacitances as described above. Here, the reference voltage adjustment circuit 40 includes a comparator 41, a control circuit 42, a register 43, a D / A converter 44, and an adjustment unit 45.

  For example, the reference voltage adjustment circuit 40 inputs the output of the CV conversion circuit 21 from the positive input terminal of the comparator 41 and inputs the reference voltage (Reference Voltage: RV) from the negative input terminal, and compares the two. Then, the set value of the register 43 is changed under the control of the control circuit 42 based on the comparison result.

  Further, after the output of the register 43 is converted from a digital signal to an analog signal by the D / A converter 44, the voltage is adjusted by the adjusting unit 45, and the output from the adjusting unit 45 is used to adjust the voltage of the CV conversion circuit 21. Adjust the input. In this way, in the operation 1 when the hand 49 or the finger is not close to the capacitance sensor unit 10, the setting of the register 43 is performed when the output from the CV conversion circuit 21 is closest to the reference potential. The value is fixed and the output of the first initial capacity is used as the reference voltage, and the set value (set value 1) at that time is stored.

  At the same time, in the operation 2 when the hand 49 or the finger is not close to the capacitance sensor unit 10, the set value of the register 43 is set when the output from the CV conversion circuit 21 is closest to the reference potential. The second initial capacitance output is fixed as the reference potential, and the set value (set value 2) at that time is stored.

  In the actual operation 1, the output of the CV conversion circuit 21 when the set value 1 of the register 43 is fixed is input to, for example, the plus side input terminal of the subtraction circuit 31, and the reference voltage RV is minus. The value is input to the side input terminal, and the output is subtracted by the reference voltage RV to obtain the detected value 1. Further, in the actual operation 2, the output of the CV conversion circuit 21 when the register 43 is fixed to the set value 2 is input to, for example, the plus side input terminal of the subtraction circuit 31, and the reference voltage RV is minus. The value is input to the side input terminal, and the output is subtracted by the reference voltage RV to obtain the detection value 2.

  Then, by comparing these detection value 1 and detection value 2, whether or not there is a hand 49 or a finger within the detection range Z on the sensor electrode 11 and if so, how far is it? Is determined. The input to the CV conversion circuit 21 is adjusted by, for example, increasing or decreasing the input capacitance by applying the voltage of the D / A converter 44 to the adjustment unit 45 including a fixed capacitor connected to the input. Can be realized.

  FIG. 12 is an explanatory diagram illustrating an example of the overall configuration of the electrostatic capacity sensor unit and the circuit unit of the pinching prevention device according to still another embodiment of the present invention, and FIG. 13 is an operation concept during the detection operation of the pinching prevention device. FIG. 14 to FIG. 16 are explanatory diagrams for explaining the relationship between the object to be detected and the lines of electric force during the first detection operation (operation 3) of the anti-pinch device.

  FIGS. 17 to 19 are explanatory diagrams for explaining the relationship between the object to be detected and the lines of electric force during the second detection operation (operation 4) of the pinch prevention device. It should be noted that a description overlapping the part already described in the above-described embodiment may be omitted.

  As shown in FIG. 12, the pinching prevention device according to this embodiment has the same configuration as the pinching prevention device according to the above-described embodiment, and includes a capacitance sensor unit 10 and a circuit unit 20. Has been. The capacitance sensor unit 10 includes a sensor electrode 11, a shield electrode 12, and an auxiliary electrode 13A formed in a hollow long frame shape surrounding the sensor electrode 11 like the auxiliary electrode 13. Yes.

  The sensor electrode 11 is provided mainly for detecting a hand 49, a finger, and the like existing in the detection range Z of the detection area on the detection surface side. The shield electrode 12 has the above-described action. The auxiliary electrode 13 </ b> A is provided mainly to vary the equal capacitance line (surface) on the equal electrostatic side on the detection surface side of the sensor electrode 11.

  The circuit unit 20 is directly connected to the CV conversion circuit 21 connected to the sensor electrode 11 or the auxiliary electrode 13A, the A / D converter 22, the CPU 23, and the shield electrode 12, and the sensor electrode 11 or the auxiliary electrode. And a shield drive circuit 24 connected to 13A.

  The circuit unit 20 also switches the input from the sensor electrode 11 to the CV conversion circuit 21 or the shield drive circuit 24, and the input from the auxiliary electrode 13A to the shield drive circuit 24 or the CV conversion. A second changeover switch SW2 for switching to the circuit 21 is provided. The first and second changeover switches SW1 and SW2 are configured to be switchable to the A side and the B side (see FIG. 12 and the like), respectively.

  The CV conversion circuit 21 converts the capacitance detected by the sensor electrode 11 or the auxiliary electrode 13A into a voltage. The A / D converter 22 operates in the same manner as described above. The CPU 23 controls the entire anti-pinch device, and controls the operation of the alternate connection (an alternative connection to the A side or B side) of the first and second changeover switches SW1 and SW2, for example. The detection of the detection target (hand 49 or finger) in the detection area (proximity or presence of hand 49 or finger) is determined. The shield drive circuit 24 drives the shield electrode 12 and the auxiliary electrode 13A or the sensor electrode 11 to, for example, the same potential as the sensor electrode 11.

  Since the structure and configuration of the capacitance sensor unit 10 and the circuit unit 20 and the structure and configuration of the electrodes 11 to 13A are the same as those already described in the above-described embodiment, the description thereof is omitted here. . Note that the first changeover switch SW1 is configured such that, for example, when the sensor electrode 11 is not connected to the CV conversion circuit 21, the sensor electrode 11 can be opened, grounded, or connected to a predetermined potential. The second changeover switch SW2 May be configured such that when the sensor electrode 11 is connected to the CV conversion circuit 21, the auxiliary electrode 13A can be opened, grounded, or connected to a predetermined potential.

  The shield drive circuit 24 is configured to give the auxiliary electrode 13A a potential equivalent to that of the sensor electrode 11, or to give the sensor electrode 11 a potential equivalent to that of the auxiliary electrode 13A. The first changeover switch SW1 is configured so that the sensor electrode 11 can be connected to the shield drive circuit 24 when the sensor electrode 11 is not connected to the CV conversion circuit 21, and the second changeover switch SW2 is configured so that the sensor electrode 11 is connected to the shield drive circuit 24. The auxiliary electrode 13 </ b> A may be configured to be connectable to the shield drive circuit 24 when connected to the CV conversion circuit 21.

  Further, the shield drive circuit 24 may be configured to apply a potential equivalent to that of the sensor electrode 11 to the auxiliary electrode 13A. In this case, the first changeover switch SW1 has the sensor electrode 11 connected to the CV conversion circuit 21. The auxiliary electrode 13A may be open, grounded, or connectable to a predetermined potential when not connected. The second changeover switch SW2 may be configured to connect the auxiliary electrode 13A to the shield drive circuit 24 when the sensor electrode 11 is connected to the CV conversion circuit 21.

  The shield drive circuit 24 is configured to give the sensor electrode 11 the same potential as the auxiliary electrode 13A. In this case, the first changeover switch SW1 is not connected to the CV conversion circuit 21. Sometimes, the auxiliary electrode 13A may be configured to be connectable to the shield drive circuit 24. The second changeover switch SW2 may be configured so that the auxiliary electrode 13A can be opened, grounded, or connected to a predetermined potential when the sensor electrode 11 is connected to the CV conversion circuit 21.

  Next, an object detection operation of the anti-pinch device configured as described above will be described. First, under the control of the CPU 23, both the first and second changeover switches SW 1 and SW 2 are switched to the A side, and the sensor electrode 11 is connected to the CV conversion circuit 21. In addition, an operation (operation 3) when the shield electrode 12 and the auxiliary electrode 13A are connected to the shield drive circuit 24 will be described.

  In the case of the operation 3, the connection state of the sensor electrode 11, the shield electrode 12, and the auxiliary electrode 13A with the circuit unit 20 is as shown in FIG. That is, as described above, only the sensor electrode 11 is connected to the CV conversion circuit 21, and the shield electrode 12 and the auxiliary electrode 13 </ b> A are connected to the shield drive circuit 24. Thereby, the electrostatic capacitance C with the detection objects X, Y, W is detected by the CV conversion circuit 21 only by the sensor electrode 11.

  Note that the back surface side of the sensor electrode 11 of the capacitance sensor unit 10 is covered with the shield electrode 12. For this reason, the sensor sensitivity on the back surface side of the sensor electrode 11 is considerably lower than that on the detection surface side because only the electric lines of force that wrap around from the detection surface (front surface) of the sensor electrode 11 are detected. Here, the detection target object X is described as a detection target object existing in the detection range Z, and the detection target objects Y and W are described as detection target objects existing outside the detection range Z.

  As shown in FIG. 14, the electric lines of force P1 from the sensor electrode 11 to the detection target X are less affected by the electric lines of force P2 (shield) from the auxiliary electrode 13A.

  On the other hand, as shown in FIG. 15, the electric lines of force P1 from the sensor electrode 11 with respect to the detection target Y at a distance substantially equal to the detection target X are affected by the electric lines of force P2 (shield) from the auxiliary electrode 13A. In response to this, it decreases compared to the case of the detection object X. For this reason, the detection target Y is weaker in capacitive coupling with the sensor electrode 11 than the detection target X.

  As a result, it is possible to easily identify the detection objects X and Y in the operation 3 (that is, whether the detection objects are within the detection range Z or outside the detection range Z). However, as shown in FIG. 16, in the detection target W closer to the sensor electrode 11 than the detection target Y, the electric lines of force P1 from the sensor electrode 11 are the same as those for the detection target X in FIG. , The output from the CV conversion circuit 21 is the same.

  That is, the detection target object X and the detection target object W are on the equipotential surface (line) M in FIG. 13, and the detection value (capacitance value) in the operation 3 is the same. For this reason, it is difficult to identify whether the detection object W exists within the detection range Z or outside the detection range Z only by this operation 3. In this embodiment as well, as in the above-described embodiment, the determination is not made only by the operation 3, but the electrostatic capacitance as the first capacitance value detected by the CV conversion circuit 21 at the time of the operation 3 is determined. The capacitance value C1 is stored in the storage means by the CPU 23.

  Next, under the control of the CPU 23, both the first and second changeover switches SW 1 and SW 2 are switched to the B side, and the auxiliary electrode 13 A is connected to the CV conversion circuit 21. In addition, an operation (operation 4) when the shield electrode 12 and the sensor electrode 11 are connected to the shield drive circuit 24 will be described.

  In addition, the structure corresponding to FIG. 13 which shows the connection state with the circuit part 20 of the sensor electrode 11, the shield electrode 12, and the auxiliary electrode 13A in the pinching prevention device in the case of the operation 4 has each changeover switch SW1, SW2 in FIG. Switched to the B side. For this reason, illustration and description are omitted here.

  In this operation 4, only the auxiliary electrode 13 </ b> A is connected to the CV conversion circuit 21, and the shield electrode 12 and the sensor electrode 11 are connected to the shield drive circuit 24. Thereby, the capacitance C with the detection objects X, Y, W is detected by the CV conversion circuit 21 only by the auxiliary electrode 13A. It is assumed that various conditions such as the arrangement positions of the detection objects X, Y, and W with respect to the capacitance sensor units 10 and 20 are the same as those in the operation 3.

  In the case of this operation 4, as shown in FIG. 17, the electric force line P2 (shield) from the sensor electrode 11 with respect to the detection target X has a great influence on the electric force line P1 from the auxiliary electrode 13A. For this reason, the detection object X has weak capacitance coupling with the auxiliary electrode 13A, and the capacitance value detected by the CV conversion circuit 21 is compared with the detection object X in the operation 3. Become smaller.

  On the other hand, as shown in FIG. 18, the electric force line P2 (shield) from the sensor electrode 11 with respect to the detection target Y is reduced as compared with the case with respect to the detection target X, and the electric force line P1 from the auxiliary electrode 13A. Increases compared to the case of the detection object X. For this reason, in the case of the operation 4, the detection target Y has a strong capacitive coupling with the auxiliary electrode 13A, and the capacitance value detected by the CV conversion circuit 21 is the detection target in the operation 3. Compared to the case for the object Y, it becomes larger.

  Further, as shown in FIG. 19, the electric lines of force P1 from the auxiliary electrode 13A to the detection object W are larger than the electric lines of force P1 from the auxiliary electrode 13A to the detection object X in FIG. The influence of the electric lines of force P2 (shield) from the electrode 11 is also small. For this reason, in the operation 4, the output from the CV conversion circuit 21 in the detection target W is larger than that in the detection target X. Then, the capacitance value C2 as the second capacitance value detected by the CV conversion circuit 21 during the operation 4 is stored in the storage means by the CPU 23.

  If the first and second capacitance values C1 and C2 are detected in this way, the CPU 23 compares these capacitance values C1 and C2 stored in the storage means. For example, in the detection object X described above, the first capacitance value C1 in the operation 3 is larger than the second capacitance value C2 in the operation 4, but in the detection object Y, the operation The first capacitance value C1 at 3 is smaller than the second capacitance value C2 at operation 4. For this reason, in the detection target W, the first capacitance value C1 in the operation 3 and the second capacitance value C2 in the operation 4 are approximately the same.

  As described above, the CPU 23 determines how far the detection target exists from the center of the sensor electrode 11 by comparing the value of the capacitance value C2 with the capacitance value C1. Is possible. At this time, if the comparison value of the capacitance values C1 and C2 is, for example, a predetermined threshold value or more (or less than a predetermined threshold value or less than a predetermined threshold value), the sensor electrode 11 If it is set so that it can be determined that it is within the upper detection range Z, directivity can be arbitrarily given.

  In the explanatory diagrams shown in FIGS. 13 to 19, the detection value in the operation 3 is larger than the detection value in the operation 4 for the detection target X, and the detection value in the operation 3 is the detection value in the operation 3 for the detection target Y. Smaller than the detected value. In the detection target W, the detection value in the operation 3 and the detection value in the operation 4 are described as examples. However, when various conditions such as the arrangement shape and the arrangement area of the sensor electrode 11 and the auxiliary electrode 13A change, the vertical relationship between the operation 3 and the operation 4 on the detection objects X, Y, and W changes.

  However, the ratio (C2 / C1) of the second capacitance value C2 in the operation 4 to the first capacitance value C1 in the operation 3 is always the detection object X <the detection object Y (or the detection object W). ) So that it can be distinguished. Therefore, if the comparison formula between the operation 3 and the operation 4 is changed for each condition, the detection objects X, Y, and W can be determined. Note that the comparison formulas, comparison values, various coefficients, predetermined threshold values (Th1, Th2), and the like are the same as those described in the above-described embodiment, and thus description thereof is omitted here.

  Although there are cases where it cannot be expressed by a mathematical expression depending on conditions, the values of the capacitance values C1 and C2 at the position of the detection target (hand 49 or finger) are measured and profiled in advance, and each profile and the actual What is necessary is just to compare with a detected value.

  Thus, according to this pinching prevention device, for example, when the predetermined threshold Th2 is large, the directivity intensity of the sensor sensitivity of the capacitance sensor unit 10 is high, and when the predetermined threshold Th2 is small, the directivity intensity is low. It can be. Thereby, the directivity of the sensor sensitivity can be arbitrarily set, and the detection range Z on the sensor electrode 11 can be arbitrarily determined, and the detection object (hand 49 or the like) within the detection range Z having the desired directivity can be obtained. The proximity of a finger etc.) can be detected reliably and accurately with a simple configuration.

  For example, when the hand 49 or the finger is detected based on the determination result, the closing operation is stopped even if the window 3A is closing. In this way, it is possible to prevent the object from being caught between the window 3A and the window frame 3B safely and surely before the object actually contacts the window 3A or the window frame 3B. .

  Note that the various configurations and operations of the CV conversion circuit 21 of the circuit unit 20 are the same as those described in the above-described embodiment, and thus description thereof is omitted here. Further, in the pinching prevention device according to the present embodiment, the sensor electrode 11, the shield electrode 12, and the auxiliary electrode 13A are arranged, and the electrostatic capacitance value C1 of the sensor electrode 11 and the electrostatic capacitance value C2 of the auxiliary electrode 13A are obtained. The comparison and determination of the detection target object have been described as examples. In addition, as described with reference to FIG. 8 in the above-described embodiment, the dummy electrode 19 may be disposed and the CV conversion circuit 21 may be configured to perform a differential operation. Since the various configurations and operations are the same as those described above, the description thereof is omitted here.

  Further, since the various configurations and operations of the modified example of the shield drive circuit 24 and the modified examples of the first and second changeover switches SW1 and SW2 are the same as those described in the above-described embodiment, Description is omitted.

  In addition, in the pinching prevention device according to the present embodiment, the auxiliary electrode 13A is arranged so as to surround the entire periphery of the sensor electrode 11. Therefore, the capacitance sensor unit 10 has the same directivity in all directions of the detection surface of the sensor electrode 11 (that is, the detection range Z is the same in any direction with respect to the sensor electrode 11), but it is desired to have the directivity. When there is no direction, for example, the following may be performed.

  That is, the auxiliary electrode 13A is not disposed in a direction in which directivity is not desired, and the auxiliary electrode 13A is formed in a U shape, a C shape, an L shape, a semicircle, or the like, for example. It is also possible to reduce the directivity in the direction where there is no noise.

  Further, since the output from the CV conversion circuit 21 of the circuit unit 20 described above is either the first capacitance value C1 or the second capacitance value C2, the sensor electrode 11 (including the static capacitance 11) is included. The capacitance value detected may vary depending on the structure around the place where the capacitance sensor unit 10) is installed.

  Then, the comparison result obtained by comparing the first and second capacitance values C1 and C2 may change depending on the structure around the place where the sensor electrode 11 is installed. In order to avoid such a situation, the configuration of the circuit unit 20 may be further configured as follows, for example.

  FIG. 20 is an explanatory diagram showing an example of the overall configuration of the capacitance sensor unit and the circuit unit of the anti-pinch device according to still another embodiment of the present invention, and FIG. 21 shows the capacitance sensor unit and the circuit unit of the anti-pinch device. It is explanatory drawing which shows the other example of the whole structure of a circuit part. Note that, in the above-described embodiment, the same reference numerals are given to portions overlapping with the already described portions, and the description is omitted.

  As shown in FIG. 20, the circuit unit 20 includes a CV conversion circuit 21, a shield drive circuit 24, a determination circuit 25, an initial capacity storage device 26 that stores the above-described initial capacity, and a switching operation of each switch SW1 and SW2. A switch control circuit 27 for controlling the signal and a buffer 28.

  As an outline of the detection operation of the pinching prevention device having such a circuit unit 20, for example, after the capacitance sensor unit 10 is installed at a predetermined installation location, a hand 49 or a finger approaches the capacitance sensor unit 10. The capacitance value (initial capacitance) when not being switched is detected by switching the switches SW1 and SW2 under the control of the switch control circuit 27, and these values are stored in the initial capacitance storage device 26.

  Then, the initial capacitance stored in the initial capacity storage device 26 is subtracted from the first and second capacitance values C1 and C2 in the actual operation 3 and 4 described above in the determination circuit 25 and compared. Based on the comparison result, it is determined whether or not the hand 49 or the finger is within the detection range Z on the sensor electrode 11.

  Specifically, the initial capacity is set as the first initial capacity at the time of the above operation 3 when the respective switches SW1 and SW2 are connected to the A side under the control of the switch control circuit 27. The switch at the time of the above operation 4 when the switches SW1 and SW2 are connected to the B side is stored in the initial capacity storage device 26 as the second initial capacity.

  In the actual operation 3, the determination circuit 25 subtracts the first initial capacitance stored in the initial capacitance storage device 26 from the detected first capacitance value C1 and performs the first detection. A value (detection value 1), and in the case of operation 4, the second detection value is obtained by subtracting the second initial capacitance stored in the initial capacitance storage device 26 from the detected second capacitance value C2. (Detection value 2).

  Thereafter, the determination circuit 25 compares the detection value 1 and the detection value 2, and determines whether or not there is a hand 49 or a finger in the detection range Z based on the comparison result. For example, the detection value 1 at the time of the operation 3 is an output depending on the approach to the capacitance sensor unit 10 such as the hand 49 or the finger. Since subsequent operations, functions, effects, and the like are the same as those described in the above-described embodiment, description thereof is omitted here.

  The first and second initial capacitances described above may be, for example, digitally converted from the voltage at the time of initial capacitance measurement by an A / D converter or the like and held in a register or a memory. Thus, it is possible to hold these by adjusting the reference voltage. That is, as shown in FIG. 21, the circuit unit 20 includes a CV conversion circuit 21, a shield drive circuit 24, a reference voltage adjustment circuit 40, and a subtraction circuit 31.

  The reference voltage adjustment circuit 40 is for adjusting the output of the CV conversion circuit 21 to the reference potential at the time of initial capacitance measurement of the first and second initial capacitances as described above. , A comparator 41, a control circuit 42, a register 43, a D / A converter 44, and an adjustment unit 45. Since these configurations, operations, and the like are also the same as those described in the above-described embodiment, description thereof is omitted here.

  The output of the first and second initial capacitors is set as a reference voltage by the reference voltage adjustment circuit 40, and the output of the CV conversion circuit 21 thus set to the reference voltage is applied to, for example, the positive side input terminal of the subtraction circuit 31. Then, the reference voltage RV is input to the negative input terminal, the output is subtracted by the reference voltage RV, and the first and second initial capacitances are subtracted. Similarly, there are a hand 49 and a finger within the detection range Z. It is possible to determine whether or not, and if so, how long the distance is.

  As described above, according to the pinching prevention device according to the above-described embodiment, the occupant's hand 49 or finger is placed within the detection range Z having the desired directivity on the sensor electrode 11 by the capacitance sensor unit 10. It can be determined whether or not there is. If the hand 49 or the finger is detected based on the determination result, the closing operation of the window 3A can be stopped to prevent the pinching. In this way, it is possible to prevent pinching of the hand 49 and fingers safely and surely before actually contacting the window 3A or the like.

  In addition, although the pinching prevention device according to the above-described embodiment has been applied to the window 3A and the window frame portion 3B as the opening / closing portion, it can be applied to other opening / closing portions such as a vehicle door (especially a sliding door) and an automatic door. Can also be applied.

DESCRIPTION OF SYMBOLS 1 Vehicle 3A Window 3B Window frame part 10 Capacitance sensor part 11 Sensor electrode 12 Shield electrode 13 Auxiliary electrode 13A Auxiliary electrode 19 Dummy electrode 20 Circuit part 21 CV conversion circuit 22 A / D converter 23 CPU
24 Shield Drive Circuit 25 Judgment Circuit 26 Initial Capacity Storage Device 27 Switch Control Circuit 28 Buffer 30 Circuit Unit 31 Subtraction Circuit 40 Reference Voltage Adjustment Circuit 41 Comparator 42 Control Circuit 43 Register 44 D / A Converter 45 Adjustment Unit

Claims (12)

An opening / closing member provided in a vehicle and an opening / closing part made up of an opening / closing part that contacts the opening / closing member when the opening / closing member is in a fully-closed state. A sensor electrode;
An auxiliary electrode provided in the vicinity of the sensor electrode;
A detection circuit connected to at least the sensor electrode and detecting a capacitance value based on a capacitance from the connected electrode;
A changeover switch capable of selectively switching between a first connection state in which the auxiliary electrode is not connected to the detection circuit and a second connection state in which the auxiliary electrode is connected to the detection circuit;
A comparison value comparing a first capacitance value from the detection circuit in the first connection state with a second capacitance value from the detection circuit in the second connection state; and the first An opening / closing operation control means for determining whether or not an object is within a detection range on the sensor electrode based on the first or second capacitance value and controlling the opening / closing operation of the opening / closing member based on the determination result An anti-pinch device characterized by comprising: The pinch prevention device according to claim 1, wherein the change-over switch is configured to be able to open, ground, or connect the auxiliary electrode to a predetermined potential in the first connection state. A shield driving circuit for applying a potential equal to that of the sensor electrode to the auxiliary electrode;
The pinching prevention device according to claim 1, wherein the changeover switch is configured to be able to connect the auxiliary electrode to the shield drive circuit when in the first connection state. A sensor electrode disposed at an abutting side end of any one of an opening / closing member provided in the vehicle and a member to be contacted when the opening / closing member is in a fully closed state;
An auxiliary electrode provided in the vicinity of the sensor electrode;
A detection circuit for detecting a capacitance value based on a capacitance from the sensor electrode;
A shield drive circuit for applying a potential equal to that of the sensor electrode to the auxiliary electrode;
A changeover switch capable of selectively switching between a first connection state in which the auxiliary electrode is connected to the shield drive circuit and a second connection state in which the auxiliary electrode is opened, grounded or connected to a predetermined potential;
A comparison value comparing a first capacitance value from the detection circuit in the first connection state with a second capacitance value from the detection circuit in the second connection state; and the first An opening / closing operation control means for determining whether or not an object is within a detection range on the sensor electrode based on the first or second capacitance value and controlling the opening / closing operation of the opening / closing member based on the determination result An anti-pinch device characterized by comprising: An opening / closing member provided in a vehicle and a sensor electrode disposed at one end of a contact side of the contacted member that contacts when the opening / closing member is in a completely closed state;
An auxiliary electrode provided in the vicinity of the sensor electrode;
A detection circuit for detecting a capacitance value based on the capacitance from the connected electrodes;
A first changeover switch capable of selectively switching between a first connection state in which the sensor electrode is connected to the detection circuit and a second connection state in which the sensor electrode is not connected to the detection circuit;
When the sensor electrode is in the first connection state, the auxiliary electrode is not connected to the detection circuit, and when the first changeover switch is in the second connection state, the auxiliary electrode is connected to the detection circuit. A switchable second changeover switch,
A comparison value comparing the first capacitance value from the detection circuit in the case of the first connection state and the second capacitance value from the detection circuit in the case of the second connection state. And based on the first or second capacitance value, it is determined whether or not the object is within a detection range on the sensor electrode, and the opening / closing operation of the opening / closing member is controlled based on the determination result. An anti-pinch device characterized by comprising an opening / closing operation control means. The first changeover switch is configured to be able to open the sensor electrode, connect to ground or a predetermined potential in the second connection state,
The pinching prevention device according to claim 5, wherein the second changeover switch is configured to be able to open, ground, or connect the auxiliary electrode to a predetermined potential in the first connection state. A shield driving circuit for giving the auxiliary electrode the same potential as the sensor electrode, or giving the sensor electrode the same potential as the auxiliary electrode,
The first changeover switch is configured to connect the sensor electrode to the shield drive circuit in the second connection state,
The pinching prevention device according to claim 5, wherein the second changeover switch is configured to be able to connect the auxiliary electrode to the shield drive circuit in the first connection state. A shield driving circuit for applying a potential equal to that of the sensor electrode to the auxiliary electrode;
The first changeover switch is configured to be able to open the auxiliary electrode in the second connection state, connect to ground or a predetermined potential,
The pinching prevention device according to claim 5, wherein the second changeover switch is configured to be able to connect the auxiliary electrode to the shield drive circuit in the first connection state. A shield driving circuit for applying a potential equal to that of the auxiliary electrode to the sensor electrode;
The first changeover switch is configured to connect the auxiliary electrode to the shield drive circuit in the second connection state,
The pinching prevention device according to claim 5, wherein the second changeover switch is configured to be able to open, ground, or connect the auxiliary electrode to a predetermined potential in the first connection state. The pinching prevention device according to any one of claims 1 to 9, wherein the auxiliary electrode is disposed so as to surround the sensor electrode. The opening / closing operation control means stops the opening / closing operation of the opening / closing member when it is determined that the object is within a detection range on the sensor electrode. The pinching prevention device according to item. The pinching prevention device according to any one of claims 1 to 11, wherein the opening / closing member is at least one of a window and a door of a vehicle.

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