JP2013098637A - Proximity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a proximity sensor that readily detects a detectable body inserted in an article storage space with accuracy.SOLUTION: The proximity sensor includes: a sensor structure B for forming a capacitance with a detectable body 8 inserted in an article storage space D; and a sensor circuit C for detecting the insertion of the detectable body 8 on the basis of the capacitance. The sensor structure B includes: a first detection electrode 9 arranged beside the article storage space D; a second detection electrode 10 juxtaposed with the first detection electrode 9; and a shield electrode 11 electrostatically shielding the first and second detection electrodes 9, 10 from the side opposite to the article storage space side entirely over the article storage space D. The sensor circuit C is configured to detect the detectable body 8 inserted in the article storage space D on the basis of a first capacitance Ca formed between the detectable body 8 and the first detection electrode 9 and a second capacitance Cb formed between the detectable body 8 and the second detection electrode 10.

Description

  The present invention includes a sensor structure that forms a capacitance with a body to be detected, and a sensor circuit that detects the body to be detected based on the capacitance. A first sensing electrode; a second sensing electrode arranged in parallel with the first sensing electrode; and a shielding electrode that electrostatically shields the first and second sensing electrodes; And a first capacitance formed between the first sensing electrode and a second capacitance formed between the detected body and the second sensing electrode. The present invention relates to a proximity sensor that can detect a body.

  In the proximity sensor, a sensor structure including a shielding electrode having a size corresponding to the dimensions of the first and second detection electrodes is conventionally provided (see, for example, Patent Document 1).

Japanese Patent No. 4578980

For example, in order to install a proximity sensor capable of detecting an object to be detected such as a human finger inserted into an article storage space in an article storage space such as a door pocket provided inside a door of an automobile, for example, If the sensor structure is provided, the size of the shielding electrode may be smaller than the size of the article storage space.
In this case, an object existing on the side opposite to the article storage space side with respect to the first and second detection electrodes, for example, an object different from the storage article such as the door body, and a storage article in the article storage space are capacitively coupled. As a result, a large electrostatic capacity is formed, and the object may be erroneously detected as a detection object inserted into the article storage space.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a proximity sensor that can accurately detect a detection object inserted in an article storage space.

  A first characteristic configuration of the proximity sensor according to the present invention includes a sensor structure that forms a capacitance with a detected object inserted into the article storage space, and insertion of the detected object into the article storage space. A sensor circuit that detects based on the capacitance, and the sensor structure is arranged in parallel with the first sensing electrode and the first sensing electrode disposed on the side of the article storage space. A second sensing electrode, and a shielding electrode that electrostatically shields the first and second sensing electrodes from the opposite side of the article storage space over the entire article storage space, The circuit includes a first capacitance formed between the detected body and the first detection electrode, and a second capacitance formed between the detected body and the second detection electrode. The detected object inserted into the article storage space is provided based on There is a point.

In the proximity sensor of this configuration, the sensor structure has a first detection electrode disposed on the side of the article storage space, a second detection electrode arranged in parallel with the first detection electrode, and first and first (2) A shielding electrode that electrostatically shields the sensing electrode from the opposite side of the article storage space over the entire article storage space.
For this reason, it is possible to suppress the formation of a large capacitance due to capacitive coupling between an object present on the opposite side of the article storage space side of the first and second detection electrodes and an article stored in the article storage space, There is no possibility that the object is erroneously detected as a detection object inserted into the article storage space.
Therefore, with the proximity sensor of this configuration, it is easy to accurately detect the detected object inserted into the article storage space.

  According to a second characteristic configuration of the present invention, a storage port of the article storage space is formed on one end side along a parallel arrangement direction of the first detection electrode and the second detection electrode, and the first detection electrode is , In that it is arranged to be offset toward the storage opening.

By shifting the first detection electrode toward the storage port as in this configuration, it is not necessary to provide the first detection electrode over the entire area of the article storage space, and the size of the first detection electrode is reduced (the electrode area is reduced). Can be achieved.
Moreover, since the storage port of the article storage space is a part into which the detection object is inserted, the detection accuracy of the detection object can be maintained high.

  A third characteristic configuration of the proximity sensor according to the present invention includes a sensor structure that forms a capacitance with a detected object inserted into the article storage space, and insertion of the detected object into the article storage space. A sensor circuit for detecting based on the capacitance, wherein the sensor structure includes a first detection electrode, a second detection electrode arranged in parallel with the first detection electrode, and the first and first A sensor electrode that electrostatically shields the two detection electrodes from a side opposite to the side of the article storage space, on the upper side in the insertion direction of the detected object with respect to the storage port of the article storage space; Are a first capacitance formed between the detected body and the first sensing electrode, and a second capacitance formed between the detected body and the second sensing electrode. Based on the above, the object to be detected inserted into the article storage space is provided so as to be detectable. There to that point.

In the proximity sensor of this configuration, the sensor structure has a first detection electrode, a second detection electrode arranged in parallel with the first detection electrode, and the first and second detection electrodes opposite to the article storage space side. A shielding electrode that electrostatically shields from the side of the object is provided on the upper side in the insertion direction of the detection object with respect to the storage port of the article storage space.
For this reason, it is possible to suppress the formation of a large capacitance due to capacitive coupling between an object present on the opposite side of the article storage space side of the first and second detection electrodes and an article stored in the article storage space, There is no possibility that the object is erroneously detected as a detection object inserted into the article storage space.
In particular, since the first detection electrode, the second detection electrode, and the shielding electrode are provided on the upper side in the insertion direction of the detection object with respect to the storage port of the article storage space, the detection target immediately before being inserted from the storage port is provided. Based on the detected information, for example, it is possible to control the lighting / extinguishing operation of the lamp that illuminates the article storage space with good timing.
Therefore, with the proximity sensor of this configuration, it is easy to accurately detect the detection object inserted into the article storage space at an early timing.

It is a perspective view which shows the door pocket of the motor vehicle provided with the proximity sensor. It is the schematic sectional drawing of a door pocket, and the circuit diagram of a proximity sensor. It is the schematic sectional drawing of the door pocket which shows 2nd Embodiment, and the circuit diagram of a proximity sensor. It is the schematic sectional drawing of the door pocket which shows 3rd Embodiment, and the circuit diagram of a proximity sensor.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
1 and 2 show a door pocket D of an automobile as an article storage space equipped with a proximity sensor A according to the present invention.
The door pocket D has a non-conductive material such as resin inside the door panel 3 (the interior material 2 side) provided with an interior material 2 formed of a non-conductive material such as resin inside the steel exterior plate 1. The pocket forming member 4 formed in the above is attached and formed inside.

  The door pocket D includes a storage opening 5 that opens upward, a door pocket lamp 6 that illuminates the interior of the door pocket D, and a lamp control unit 7 that controls the turning on / off operation of the door pocket lamp 6.

The proximity sensor A is provided so as to be able to detect, for example, a human finger 8 as a detected object inserted into the door pocket D from the storage port 5.
The lamp controller 7 controls the lighting / extinguishing operation of the door pocket lamp 6 based on the detection information by the proximity sensor A of the finger 8 inserted into the door pocket D.

  The proximity sensor A includes a sensor structure B that forms a capacitance between the finger 8 inserted into the door pocket D and an electrostatic sensor formed by inserting the finger 8 into the door pocket D into the sensor structure B. And a sensor circuit C that detects based on the capacitance.

The sensor structure B includes a rectangular plate-shaped first detection electrode 9 disposed in the vertical direction on the side of the door pocket D on the side of the door panel, and a vertical direction on the outer peripheral side of the first detection electrode 9. The rectangular frame plate-like second detection electrode 10 and the first and second detection electrodes 9 and 10 that are arranged side by side are arranged over the entire door pocket D from the side opposite to the door pocket D side. The interior material 2 of the door panel 3 is provided with a rectangular plate-shaped shielding electrode 11 for electrostatic shielding.
Accordingly, the storage port 5 is formed at one end on the upper side along the direction in which the first detection electrode 9 and the second detection electrode 10 of the door pocket D are arranged side by side.

The first detection electrode 9 has a larger electrode area than the stored item E in the door pocket D, and forms a large capacitance with the finger 8 inserted into the door pocket D.
For this reason, the 1st detection electrode 9 is formed in the dimension exceeding the dimension of the door pocket D so that the door panel 3 side of the door pocket D may be covered over the whole surface, and between the door pocket D and the exterior board 1 is formed. It is provided in the interior material part.

  The second detection electrode 10 is formed in an annular shape that surrounds the outer peripheral edge of the first detection electrode 9 at a constant interval in the direction along the plate surface, and is arranged flush with the first detection electrode 9. A noise suppression electrode is configured to detect external noise such as radio waves and environmental noise.

The second sensing electrode 10 has an electrode area sufficiently smaller than that of the first sensing electrode 9 so as to have a sufficiently small grounding capacity with respect to the grounding capacity of the first sensing electrode 9.
The first and second detection electrodes 9 and 10 have electrode lengths that can be detected at the same level against external noise.

The shielding electrode 11 is the same as the outer peripheral size of the second detection electrode 10 or the second detection electrode so that the influence of the human body outside the door panel 3 other than the fingers 8 inserted into the door pocket D and the exterior plate 1 can be eliminated. The first and second detection electrodes 9 and 10 are disposed on the opposite side of the door pocket D with the first and second detection electrodes 9 and 10 interposed therebetween. Are provided in the interior material portion in a posture along the vertical direction parallel to each other at regular intervals.
Accordingly, it is possible to suppress the formation of a large capacitance due to capacitive coupling between the stored item E stored in the door pocket D and the human body outside the door panel 3 or the exterior plate 1.

As shown in FIG. 2, the sensor circuit C includes a first capacitance Ca formed between the finger 8 inserted into the door pocket D and the first detection electrode 9, and a finger inserted into the door pocket D. The finger 8 inserted into the door pocket D is provided so as to be detected based on the second capacitance Cb formed between the second detection electrode 10 and the second detection electrode 10.
That is, the sensor circuit C includes a first capacitance detection circuit 12, a second capacitance detection circuit 13, a difference detection circuit 14, a shielding voltage application circuit 15, a timing control circuit 16, and the like.

Each of the first and second detection electrodes 9 and 10 forms first and second capacitances (grounding capacitances) Ca and Cb with respect to a common ground potential (common reference potential) GND.
The first capacitance Ca is detected (measured) by the first capacitance detection circuit 12, and the second capacitance Cb is detected (measured) by the second capacitance detection circuit 13.
Each of the first and second capacitance detection circuits 12 and 13 detects the first and second capacitances Ca and Cb by the switched capacitor operation.

The first and second capacitances Ca and Cb detected by the first and second capacitance detection circuits 12 and 13 are input to the difference detection circuit 14.
The difference detection circuit 14 uses the difference Vo (Ca−Cb) between the first capacitance Ca and the second capacitance Cb as detection information that reflects whether or not the finger 8 is inserted into the door pocket D. 7 is output.

A shielding voltage is applied to the shielding electrode 11 by the shielding voltage application circuit 15 so as to have the same potential as the first and second detection electrodes 9 and 10.
Accordingly, since the capacitance detection circuits 12 and 13 detect the first and second capacitances Ca and Cb while applying the same potential to the first and second detection electrodes 9 and 10 and the shielding electrode 11, the first and second capacitances are detected. 2 Charge / discharge of electric charge is not performed between the detection electrodes 9 and 10 and the shielding electrode 11, and the capacitance between them is equivalently canceled.

  The timing control circuit 16 includes the first and second capacitance detection circuits 12 and 13 so that the shielding voltage is applied to the shielding electrode 11 only during the detection (measurement) of the first and second capacitances Ca and Cb. Timing is synchronized with the shielding voltage application circuit 15.

The difference Vo between the first capacitance Ca and the second capacitance Cb is small when the finger 8 is not inserted into the door pocket D, and increases as the finger 8 is inserted into the door pocket D.
Accordingly, the lamp control unit 7 detects the insertion of the finger 8 into the door pocket D when the input difference Vo becomes a predetermined value or more, and turns on the door pocket lamp 6 to input the difference Vo. Is less than a predetermined value, the extraction of the finger 8 from the door pocket D is detected, and the door pocket lamp 6 is turned off.

[Second Embodiment]
FIG. 3 shows another embodiment of the present invention.
In the present embodiment, the first detection electrode 9 is arranged so as to be offset toward the storage port 5 side.
That is, the sensor structure B includes a rectangular plate-shaped first detection electrode 9 that is disposed along the vertical direction so as to be offset toward the storage port 5 side of the door pocket D on the side side of the door panel. A rectangular plate-like second detection electrode 10 arranged in parallel along the vertical direction below the first detection electrode 9 and the first and second detection electrodes 9 and 10 on the door pocket D side. The interior material 2 includes a shielding electrode 11 that electrostatically shields the entire door pocket D from the opposite side.
The second detection electrode 10 is formed in a strip shape having an electrode area sufficiently smaller than that of the first detection electrode 9.
Other configurations are the same as those of the first embodiment.

[Third Embodiment]
FIG. 4 shows another embodiment of the present invention.
In the present embodiment, the sensor structure B includes the first detection electrode 9, the second detection electrode 10 arranged in parallel to the first detection electrode 9 so as to surround the first detection electrode 9, the first and first 2 The shielding electrode 11 that electrostatically shields the detection electrodes 9 and 10 from the side opposite to the door pocket D side is positioned on the upper side of the finger 8 in the insertion direction of the finger 8 relative to the storage port 5 of the door pocket D, that is, the storage port. 5 is provided in a door panel portion at a position higher than the storage opening 5 along a position directly above 5.
Other configurations are the same as those of the first embodiment.

[Other Embodiments]
1. The proximity sensor A according to the present invention may include a first detection electrode 9 in which the sensor structure B is disposed on the lower surface side of the article storage space D.
2. The proximity sensor A according to the present invention may be provided so that the detected object 8 inserted into the article storage space D can be detected based on the total capacity of the first capacitance Ca and the second capacitance Cb. Good.
3. The proximity sensor A according to the present invention may be provided so as to be able to detect the detected object 8 inserted into various article storage spaces D such as an internal space of a box other than the door pocket.
4). In the proximity sensor A according to the present invention, the storage port 5 of the article storage space D may be formed on one end side along the horizontal direction.
5. The proximity sensor A according to the present invention may be provided so as to be able to detect various detected bodies 8 other than human fingers inserted into the article storage space D.

5 Storage Port 8 Object 9 First Detection Electrode 10 Second Detection Electrode 11 Shielding Electrode B Sensor Structure C Sensor Circuit D Article Storage Space Ca First Capacitance Cb Second Capacitance

Claims (3)

A sensor structure that forms a capacitance with the object to be detected inserted into the article storage space;
A sensor circuit that detects insertion of the detected object into the article storage space based on the capacitance;
The sensor structure includes a first detection electrode disposed on a side of the article storage space, a second detection electrode arranged in parallel with the first detection electrode, and the first and second detection electrodes. A shielding electrode that electrostatically shields the entire article storage space from the side opposite to the article storage space side,
The sensor circuit includes a first capacitance formed between the detected body and the first detection electrode, and a second electrostatic capacity formed between the detected body and the second detection electrode. A proximity sensor provided so as to be able to detect the detected object inserted into the article storage space based on a capacity. The storage opening of the article storage space is formed on one end side along the juxtaposition direction of the first detection electrode and the second detection electrode,
The proximity sensor according to claim 1, wherein the first detection electrode is arranged so as to be offset toward the storage opening. A sensor structure that forms a capacitance with the object to be detected inserted into the article storage space;
A sensor circuit that detects insertion of the detected object into the article storage space based on the capacitance;
The sensor structure includes a first detection electrode, a second detection electrode arranged in parallel with the first detection electrode, and the first and second detection electrodes from a side opposite to the article storage space side. A shielding electrode for electrostatic shielding is provided on the upper side in the insertion direction of the object to be detected from the storage port of the article storage space,
The sensor circuit includes a first capacitance formed between the detected body and the first detection electrode, and a second electrostatic capacity formed between the detected body and the second detection electrode. A proximity sensor provided so as to be able to detect the detected object inserted into the article storage space based on a capacity.

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