JP2016195018A - Capacitive sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitive sensor capable of detecting presence or absence of touch to a detection surface (detection electrode) based on the capacitance.SOLUTION: A capacitive sensor includes a first detection electrode, a second detection electrode extending in a direction along the first detection electrode, and disposed while spaced apart therefrom, and constituted of an opposite part facing the first detection electrode, and a non-opposite part not facing the first detection electrode, an insulation material supporting the first detection electrode so as to be able to displace, and changing the gap of the first and second detection electrodes depending on the pressing force, and a capacitance detection circuit for connection with one of the first or second detection electrode.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a capacitance sensor.

  2. Description of the Related Art Conventionally, a technology is known that uses an electrostatic capacitance sensor that detects an electrostatic capacitance between a detection target and a detection electrode, and performs on / off control of the device according to the proximity of the detection target (see, for example, Patent Document 1). . In the capacitance type switch device described in Patent Document 1, illumination on / off control is performed according to the distance (proximity) to the detection target based on the capacitance value detected by the capacitance sensor.

JP 2006-147519 A

  However, the presence or absence of a touch on the detection surface (detection electrode) by the detection target does not change greatly because the distance between the detection target and the detection electrode hardly changes before and after the touch. Since the value is likely to fluctuate due to environmental changes such as ambient temperature and humidity, it is difficult to determine the presence or absence of a touch based on the capacitance value.

  The present invention has been made in view of the above-described problems, and provides a capacitance sensor that can detect the presence or absence of a touch (pressing contact) on a detection electrode based on a detected capacitance value. The purpose is that.

  The capacitance sensor according to the present invention is a first detection electrode and a second detection electrode that extends in a direction along the first detection electrode and is spaced apart from the first detection electrode. A second detection electrode composed of a facing portion facing the first detection electrode and a non-facing portion not facing the first detection electrode, and the first detection electrode are supported so as to be displaceable, and the first and second detections are performed according to a pressing force An insulating material for changing an interval between the electrodes and a capacitance detection circuit connected to one of the first and second detection electrodes.

According to the capacitance sensor of the present invention, only one of the first and second detection electrodes is connected to the capacitance detection circuit when the detection target is close to the electrode portion. Further, in a state where the detection target touches (presses contact) the electrode portion, the first detection electrode comes into contact with the second detection electrode by an insulating material that supports the first detection electrode so as to be displaceable, and the first and second detection electrodes are Connected to the capacitance detection circuit. Since the second sensing electrode has a facing portion that faces the first sensing electrode and a non-facing portion that does not face the first sensing electrode, if the connection state of each sensing electrode to the capacitance detection circuit changes, The electrode area for detecting the capacitance changes.
For this reason, there is a large difference in the detection value (capacitance value) output from the capacitance detection circuit before and after the detection target touches (presses contact) the electrode part, and only the capacitance value touches (presses) It is possible to determine the presence or absence of contact.

Further, in the capacitance sensor, the capacitance detection circuit is connected to the first detection electrode, and the first detection electrode is brought into contact with the facing portion, whereby the first detection electrode is interposed through the first detection electrode. Two detection electrodes may be connected to the capacitance detection circuit.
In this case, when the detection target is close to the first detection electrode, only the first detection electrode is connected to the capacitance detection circuit, and the detection value (capacitance value) output from the capacitance detection circuit is It depends only on detection by the first detection electrode. When the detection target touches (presses) the first detection electrode, not only the first detection electrode but also the second detection electrode is connected to the capacitance detection circuit via the first detection electrode, and the capacitance The detection value (capacitance value) output from the detection circuit depends on detection by the first and second detection electrodes. For this reason, after touching the electrode portion, the electrode area for detecting the capacitance with the detection target increases, and a large difference (increase) in the detection value (capacitance value) output from the capacitance detection circuit ) Occurs, and it is possible to determine the presence / absence of contact only by the capacitance value.

In the capacitance sensor, the insulating material may be a flexible film that supports the first detection electrode. Accordingly, the flexible film can be bent by the pressing contact of the object, and the first detection electrode can be brought into contact with the facing portion of the second detection electrode. The insulating material is formed by the first and second detection electrodes. An intervening spacer may be used. Thereby, the spacer can be compressed and deformed by the pressing contact of the object, and the first detection electrode can be brought into contact with the opposing portion of the second detection electrode.

Further, in the capacitance sensor, the first detection electrode may be composed of a plurality of electrode pieces arranged in parallel at intervals. Accordingly, the second detection electrode can be configured such that the facing portion and the non-facing portion are mixedly arranged.
The plurality of electrode pieces may be configured to be commonly connected to one and connected to the capacitance detection circuit. As a result, the number of wires extending to the capacitance detection circuit can be reduced to one.
The capacitance detection electrode includes a first detection circuit and a second detection circuit, and the plurality of electrode pieces are connected to an electrode piece connected to the first detection circuit and the second detection circuit. The electrode pieces may be arranged alternately. Thereby, it can be determined whether or not the touch (pressing contact) position to be detected moves, and a slide touch can be recognized.

  In the capacitance sensor, a plurality of recesses corresponding to the plurality of electrode pieces are formed on the surface of the second detection electrode, and the plurality of electrode pieces are arranged inside the plurality of recesses. It may be configured as follows. Thereby, each electrode piece is disposed so as to be surrounded by each recess, and when the detection target touches (presses contact) the first electrode part (electrode piece), the first electrode part (electrode piece) is second detected. It can be set as the structure which is easy to contact an electrode.

  ADVANTAGE OF THE INVENTION According to this invention, the electrostatic capacitance sensor which can detect the presence or absence of the touch (pressing contact) to a detection surface (detection electrode) based on the detected electrostatic capacitance value can be provided.

FIG. 1 is a schematic diagram illustrating the configuration of the capacitance sensor according to the first embodiment of the present invention, and FIG. 1A is a schematic diagram illustrating a state in which detection targets are close to each other, and FIG. ) Is a schematic diagram showing a state where the detection target touches (presses contact) the electrode part. FIG. 2 is a plan view of components of the electrode portion of the capacitance sensor, FIG. 2 (a) is a plan view of the first electrode substrate, and FIG. 2 (b) is a second electrode substrate. FIG. 2C is a plan view of the spacer. FIG. 3 is a graph for explaining the operation of the capacitance sensor. FIG. 4 is a schematic diagram showing the configuration of the capacitance sensor according to the second embodiment of the present invention. FIG. 5 is a schematic diagram showing a configuration of a capacitance sensor according to the third embodiment of the present invention. FIG. 6 is a schematic diagram showing a configuration of a capacitance sensor according to the fourth embodiment of the present invention. FIG. 7 is a plan view of components of the electrode part of the capacitance sensor, FIG. 7A is a plan view of the first electrode substrate, and FIG. 7B is a second electrode substrate. FIG. 9C is a plan view of the spacer. FIG. 8 is a schematic diagram showing a configuration of a capacitance sensor according to the fifth embodiment of the present invention.

[First Embodiment]
Hereinafter, a capacitance sensor according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic diagram illustrating a configuration of a capacitance sensor 100 according to the first embodiment. A cross-sectional view of the electrode unit 1, a capacitance detection circuit 2 and an arithmetic circuit 3 connected to the electrode unit 1 are illustrated. FIG. FIG. 1A is a diagram illustrating a state in which the detection target is close, and FIG. 1B is a diagram illustrating a state in which the detection target is touching (pressing contact) the electrode unit 1.
2 is a plan view of components of the capacitance sensor 100, FIG. 2 (a) is a plan view of the first electrode substrate 10, and FIG. 2 (b) is a diagram of the second electrode substrate 20. FIG. 2C is a plan view of the spacer 30 interposed between the first and second electrode portions.
Further, FIG. 3 is a graph for explaining the operation of the capacitance sensor, and shows the relationship between the distance between the electrode unit 1 and the detection target and the output value (capacitance value) of the capacitance sensor 100. It is a graph.

  As shown in FIGS. 1A and 1B, the capacitance sensor 100 according to the present embodiment includes an electrode unit 1 having first and second detection electrodes 11 and 21 arranged in opposition to each other, and a wiring unit 23. The capacitance detection circuit 2 is connected to the electrode unit 1 via the first electrode and detects the capacitance between the detection target and the electrode unit 1. The capacitance detection circuit 2 is connected to the capacitance detection circuit 2. And an arithmetic circuit 3 that determines the proximity of the detection target and touch (pressing contact) based on the detection value (capacitance value) output from.

  The electrode unit 1 includes a first electrode substrate 10 having a first detection electrode 11 and a flexible film 12, a second electrode substrate 20 having a second detection electrode 21 and a flexible film 22, and the first and first electrodes. The spacer 30 is interposed between the two-electrode substrates 10 and 20.

As shown in FIG. 1A, the spacer 30 supports the electrode substrates 10 and 20 with the first and second detection electrodes 11 and 21 being separated from each other. Note that only the first detection electrode 11 (electrode pieces 111 to 115) of the first electrode substrate 10 is connected to the capacitance circuit 23 via the wiring portion 23. Therefore, when the detection target is close to the electrode unit 1, the capacitance detection circuit 2 detects the capacitance between the first detection electrode 11 (electrode pieces 111 to 115) and the detection target.
That is, the capacitance sensor 100 detects the degree of proximity of the detection target only with the first detection electrode 11.

  As shown in FIG. 1B, when the detection target touches (presses contact) the electrode unit 1, the spacer 30 is compressed and deformed by the pressing force of the detection target, and the first detection electrode 11 (electrode pieces 111 to 115). Is displaced so as to contact (abut) the second detection electrode 21, and the first and second detection electrodes 11, 21 are electrically connected. As a result, the capacitance detection circuit 2 that is connected only to the first detection electrode 11 via the wiring portion 23 is also connected to the second detection electrode 21 via the first detection electrode 11. Therefore, when the detection target touches (presses) the electrode unit 1, the capacitance sensor 100 detects the proximity of the detection target with the first and second detection electrodes 11 and 21.

That is, the electrostatic capacitance sensor 100 according to the present embodiment is before and after the detection target touches (presses contact) the electrode unit 1 due to the compression deformation of the spacer 30 interposed between the first and second electrode substrates 10. It is comprised so that the area of the detection electrode for detecting the electrostatic capacitance between detection objects may change.
The first detection electrode 11 is composed of a plurality of electrode pieces 111 to 115. The second sensing electrode 21 is composed of a plurality of facing portions 211 to 215 that face the electrode pieces 111 to 115 of the first sensing electrode 11, respectively, and a non-facing portion 220 that does not face each other. The facing portions 211 to 215 function as contact points with the first detection electrode 11. The non-opposing portion 220 functions as a detection electrode for detecting the electrostatic capacitance between the first detection electrode 11 and the detection target when the first and second detection electrodes 11 and 12 are connected.

  Next, the first and second electrode substrates 10 and 20 and the spacer 30 constituting the capacitance sensor 100 will be described in detail with reference to FIG.

  As shown in FIG. 2A, the first electrode substrate 10 includes a flexible film 12, and a first detection electrode 11 composed of a plurality of electrode pieces 111 to 115 formed on the flexible film 12, Each of the electrode pieces 111 to 115 is connected in common and is composed of a wiring portion 23 extending to a capacitance detection circuit (not shown). In the present embodiment, five rectangular electrode pieces 111 to 115 are formed on the flexible film 12. The electrode pieces 111 to 115 are arranged in a row at intervals along the short direction of the electrode pieces.

As shown in FIG. 2B, the second electrode substrate 20 includes a flexible film 22 and a rectangular second detection electrode 21 formed on the flexible film 22.
When the first and second electrode substrates 10 and 20 are overlapped with the first and second detection electrodes 11 and 21 facing each other, the second detection electrode 21 has a size facing all the electrode pieces 111 to 115. Is formed.

  Further, on the surface of the second detection electrode 21, recesses 210 are respectively formed in facing portions 211 to 215 facing the electrode pieces 111 to 115 of the first detection electrode 11, and the electrode pieces 111 to 115 are placed in the recesses 210. It is configured so that it can be placed. By configuring each electrode piece 111 to 115 to be disposed in each recess 210, three sides of each electrode piece 111 to 115 are surrounded by the recess 210, and according to the pressing of the electrode part 1 by the detection target, the first Each electrode piece 111-115 of the detection electrode 11 and each opposing part 211-215 of the 2nd detection electrode 21 are easy to contact (contact) from multiple directions.

Further, the second detection electrode 21 is formed with non-opposing portions 220 that do not oppose the electrode pieces 111 to 115 of the first detection electrode 11 around the opposing portions 211 to 215 (recesses 210).
Then, when at least one of the electrode pieces 111 to 115 comes into contact (contact) with the opposing portions 211 to 215, the second detection electrode 21 detects the electrostatic capacitance between the non-opposing portion 220 and the detection target. It is configured as follows. That is, according to the area of the non-facing part 220, the electrode area for detecting the capacitance between the object to be detected after touching increases.

  For the flexible films 12 and 22 of the first and second electrode substrates 10 and 20, an insulating resin film such as polyethylene phthalate can be used. Further, the first detection electrode 11 (electrode pieces 111 to 115), the second detection electrode 21 and the wiring portion 23 can be formed on the flexible films 12 and 22 by screen printing silver paste or the like. Further, the concave portion 210 can be formed on the surface of the second detection electrode 21 by repeating screen printing such as silver paste a plurality of times.

The spacer 30 interposed between the first and second electrode substrates 10 and 20 is opened at a position corresponding to the concave portions (opposing portions 211 to 215) of the second detection electrode 21, as shown in FIG. 31-35 are formed.
The spacer 30 is made of, for example, an insulating resin material such as polyethylene terephthalate, is compressed and deformed by a pressing force, displaces the interval between the first and second detection electrodes, and the first detection electrode via the openings 31 to 35. The eleven electrode pieces 111 to 115 and the opposing portions 211 to 215 of the second detection electrode 2 can be brought into contact (contact).

Next, with reference to FIG. 3, the operation of the capacitance sensor 100 according to the present embodiment will be described. FIG. 3 is a graph showing the relationship between the distance between the detection target and the electrode unit 1 and the capacitance value detected by the capacitance sensor 100.
As described above, only the first detection electrode 11 (electrode pieces 111 to 115) is connected to the capacitance detection circuit 2 when the detection target is close to the electrode unit 1. Further, when the detection target touches (presses contact) the electrode unit 1, the spacer 30 is compressed and deformed according to the pressing force, and the first detection electrode 11 (at least one of the electrode pieces 111 to 115) is the second detection electrode. 21 (opposite portions 211 to 215) is contacted (electrically connected). Thereby, the first and second detection circuits are connected to the capacitance detection circuit 2, and not only the capacitance between the first detection electrode 11 and the detection target but also the detection target and the second detection electrode 21. The electrostatic capacitance between them is also detected. That is, before and after the touch, the electrode area for detecting the capacitance with the detection target changes.
Therefore, as shown in the graph of FIG. 3, there is a large difference in the detection value (capacitance value) output from the capacitance detection circuit before and after the detection target touches (presses contact) the electrode unit 1. The presence or absence of touch (pressing contact) can be determined only by the capacitance value.

[Second Embodiment]
Next, a capacitance sensor 100a according to a second embodiment of the present invention will be described with reference to FIG. Here, differences from the first embodiment will be described, and in FIG. 4, components having the same aspects as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
The capacitive sensor 100a according to the present embodiment is different from the capacitive sensor 100 of the first embodiment in that no recess is formed on the surface of the second detection electrode 21 of the second electrode substrate 20a. Further, the spacer 30 is thicker than the capacitance sensor 100 of the first embodiment.

Also in the present embodiment, as in the first embodiment, only the first detection electrode 11 (electrode pieces 111 to 115) is connected to the capacitance detection circuit 2 when the detection target is close to the electrode portion 1a. . In addition, when the detection target touches (presses) the electrode portion 1a, the spacer 30a is compressed and deformed, and at least one of the electrode pieces 111 to 115 of the first detection electrode 11 is moved to the second detection electrode 21 (opposing portion 211). To 215), the first and second detection electrodes 11 and 21 are connected to the capacitance detection circuit 2. Therefore, not only the capacitance between the first detection electrode 11 and the detection target, but also the capacitance between the detection target and the second detection electrode 21 is detected. Thereby, the same effect as the capacitance sensor 100 of the first embodiment can be obtained.
In the present embodiment, the second detection substrate 20a can be easily manufactured by not forming the concave portion on the surface of the second detection electrode 21.
[Third Embodiment]

Next, a capacitance sensor 100b according to a third embodiment of the present invention will be described with reference to FIG. Here, differences from the first embodiment will be described, and in FIG. 5, components having the same aspects as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.
The capacitance sensor 100b according to the present embodiment is different from the capacitance sensor 100 according to the first embodiment in that no spacer is interposed between the first and second electrode substrates 10a and 20. The flexible film 12 of the first electrode substrate 10a is formed with a plurality of curved portions 12a to 12e, and the electrode portions 111 to 115 are provided on the curved portions 12a to 12e.

Also in the present embodiment, as in the first embodiment, only the first detection electrode 11 (electrode pieces 111 to 115) is connected to the capacitance detection circuit 2 when the detection target is close to the electrode portion 1b. . Further, when the detection target touches (presses contact) the electrode portion 1b and at least one of the bending portions 12a to 12e of the flexible film 12 is bent and deformed, the electrode piece on the bending portion becomes the second detection electrode 21 ( The first and second detection electrodes 11 and 21 are connected to the capacitance detection circuit 2 in contact (contact) with the facing portions 211 to 215). For this reason, not only the capacitance between the first detection electrode 11 and the detection target, but also the capacitance between the detection target and the second detection electrode 21 is detected. Thereby, the same effect as the capacitance sensor 100 of the first embodiment can be obtained.
In this embodiment, since no spacer is used, the number of parts can be reduced.
[Fourth Embodiment]

Next, a capacitance sensor 100c according to a fourth embodiment of the present invention will be described with reference to FIGS. Here, differences from the first embodiment will be described. In FIG. 6 and FIG. 7, the same reference numerals are given to constituent elements having the same aspects as those of the above-described embodiment, and description thereof will be omitted.
The capacitance sensor 100c according to the present embodiment is different from the capacitance sensor 100 according to the first embodiment in that the capacitance detection circuit 2 includes first and second detection circuits 2a and 2b. Of the electrode pieces 111 to 115 of the first electrode substrate 10b, three electrode pieces 111, 113, and 115 are connected to the first detection circuit 2a via the wiring portion 23a, and the two electrode pieces 112 and 114 are connected. The point connected to the detection circuit 2b is different from the capacitance sensor 100 of the first embodiment.

  Also in the present embodiment, as in the first embodiment, when the detection target is close to the electrode portion 1c, only the first detection electrode 11 (electrode pieces 111 to 115) is the capacitance detection circuit 2 (first detection circuit). 2a or the second detection circuit 2b). In a state where the detection target touches (presses) the electrode portion 1c, the spacer 30 is compressed and deformed, and at least one of the electrode pieces 111 to 115 of the first detection electrode 11 is moved to the second detection electrode 21 (opposing portion 211). To 215), the first and second detection electrodes 11 and 21 are connected to the capacitance detection circuit 2. For this reason, after the touch, not only the capacitance between the first detection electrode 11 and the detection target but also the capacitance between the detection target and the second detection electrode 21 is detected. Thereby, the same effect as the capacitance sensor 100 of the first embodiment can be obtained.

Further, in the present embodiment, among the five electrode pieces 111 to 115, the electrode pieces 111, 113, 115 connected to the first detection circuit 2a and the electrode pieces 112, 114 connected to the second detection circuit 2b are alternately arranged. Therefore, it is possible to determine whether or not the touch (pressing contact) position to be detected moves, and to recognize a slide touch.
[Fifth Embodiment]

Next, a capacitance sensor 100d according to a fifth embodiment of the present invention will be described with reference to FIG. Here, differences from the first embodiment will be described, and in FIG. 8, the same reference numerals are given to the same components as those in the above-described embodiment, and the description thereof will be omitted.
The capacitance sensor 100d according to the present embodiment is different from the capacitance sensor 100 of the first embodiment in that the second detection electrode 21 is connected to the capacitance detection circuit 2 instead of the first detection electrode 11. Is different.

In the present embodiment, only the second detection electrode 21 is connected to the capacitance detection circuit 2 in a state where the detection target is close to the electrode portion 1d. At this time, since the first detection electrode 11 (electrode pieces 111 to 115) is interposed between the opposing portions 211 to 215 of the second detection electrode 21 and the detection target, between the non-opposing portion 220 and the detection target. Is detected.
In a state where the detection target touches (presses) the electrode portion 1 d, the spacer 30 is compressed and deformed, and at least one of the electrode pieces 111 to 115 of the first detection electrode 11 is moved to the second detection electrode 21 (opposing portion 211). To 215), the first and second detection electrodes 11 and 21 are connected to the capacitance detection circuit 2. Thereby, not only the electrostatic capacitance between the non-opposing portion 220 of the second detection electrode and the detection target, but also the electrostatic capacitance between the detection target and the first detection electrode 11 is detected. For this reason, when the detection target touches (presses contact) the electrode portion 1d, the electrode area for detecting the detection target increases, and the same effect as the capacitance sensor 100 of the first embodiment can be obtained. it can.

The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1,1a-1d ... Electrode part, 2 ... Capacitance detection circuit, 2a ... 1st detection circuit, 2b ... 2nd detection circuit, 3 ... Arithmetic circuit 10, 10a, 10b ... 1st electrode substrate, 11 ... 1st DESCRIPTION OF SYMBOLS 1 detection electrode, 111-115 ... electrode piece, 12 ... flexible film, 20, 20a ... 2nd electrode substrate, 21 ... 2nd detection electrode, 210 ... recessed part, 211-215, 211a-215a ... opposing part, 220 , 220a ... non-opposing part, 30, 30a ... spacer, 23, 23a-23b ... wiring part

Claims (8)

A first sensing electrode;
A second sensing electrode that extends in a direction along the first sensing electrode and is spaced apart from the first sensing electrode, and a non-facing portion that does not face the facing portion facing the first sensing electrode; A second sensing electrode comprising:
An insulating material that supports the first detection electrode in a displaceable manner and changes an interval between the first and second detection electrodes according to a pressing force;
And a capacitance detection circuit connected to one of the first and second detection electrodes. The capacitance detection circuit is connected to the first detection electrode,
The said 2nd sensing electrode is connected to the said electrostatic capacitance detection circuit via the said 1st sensing electrode when the said 1st sensing electrode contacts the said opposing part. Capacitance sensor. The capacitance sensor according to claim 1, wherein the insulating material is a flexible film that supports the first detection electrode. The capacitance sensor according to claim 1, wherein the insulating material is a spacer interposed between the first and second detection electrodes. The capacitance sensor according to any one of claims 1 to 4, wherein the first detection electrode includes a plurality of electrode pieces arranged in parallel at intervals. The capacitance sensor according to claim 5, wherein the plurality of electrode pieces are commonly connected to one and connected to the capacitance detection circuit. The capacitance detection circuit includes first and second detection circuits,
The capacitance sensor according to claim 5, wherein the plurality of electrode pieces are alternately arranged with electrode pieces connected to the first detection circuit and electrode pieces connected to the second detection circuit. . A plurality of concave portions corresponding to the plurality of electrode pieces are formed on the surface of the second detection electrode,
A plurality of said electrode pieces are arranged inside a plurality of said crevices. A capacitance sensor given in any 1 paragraph of Claims 5-7.

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