JP2002084179A - Electrostatic capacity type proximity switch - Google Patents

Electrostatic capacity type proximity switch

Info

Publication number
JP2002084179A
JP2002084179A JP2000275043A JP2000275043A JP2002084179A JP 2002084179 A JP2002084179 A JP 2002084179A JP 2000275043 A JP2000275043 A JP 2000275043A JP 2000275043 A JP2000275043 A JP 2000275043A JP 2002084179 A JP2002084179 A JP 2002084179A
Authority
JP
Japan
Prior art keywords
circuit
oscillation circuit
detection
oscillation
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2000275043A
Other languages
Japanese (ja)
Inventor
Hideki Tanaka
Naohiro Wakabayashi
秀樹 田中
尚宏 若林
Original Assignee
Gunze Ltd
グンゼ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gunze Ltd, グンゼ株式会社 filed Critical Gunze Ltd
Priority to JP2000275043A priority Critical patent/JP2002084179A/en
Publication of JP2002084179A publication Critical patent/JP2002084179A/en
Pending legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic capacity type proximity switch, built in a housing which does not have movable sections, a gap of a mount and a protrusion so as to prolong lifetime or the like of a control switch for equipment or the like. SOLUTION: The electrostatic capacity type proximity switch comprises an oscillation circuit 1 for a reference and an oscillation circuit 2 for detecting of two oscillation circuits. Components, arrangements and wirings are laid down equally on a circuit board to enhance detection accuracy. The switch further comprises a circuit for converting an oscillation frequency difference into a voltage, and a comparator for comparing the converted voltage with a reference value. Thus, the switch is built into the housing for the equipment or the like, and proximity input of a finger is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation switch for an apparatus for detecting a change in capacitance due to approach of a finger or a hand.

[0002]

2. Description of the Related Art As an operation switch incorporated in a device or the like, a mechanical switch is generally arranged in a position easy to operate. However, the mechanical switch has a feeling of operation but may be worn or damaged due to the presence of the movable part. In addition, the mounting process is costly, and dust and moisture may enter through the mounting gap, causing poor contact. In addition, since a part of the switch protrudes, the protruding portion may be damaged, and the degree of freedom in design may be limited.

[0003] In particular, switches operated in public places such as vending machines, amusement-related equipment, ticket vending machines in amusement parks, tourist information boards for displaying destinations, etc. are used in unspecified large numbers.
They are handled in a wide variety of ways and can be destroyed or damaged by unexpected impact or large forces. Further, since the installation environment is not good, the possibility of poor contact due to dust or foreign matter from a gap increases.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an operation switch for a device or the like, which has no movable portion to maintain a long life, has no gap in an attachment portion, and has no protrusion. The present invention provides an operation switch for a device or the like comprising:

[0005]

In order to solve the above-mentioned problems, an operation switch of a device or the like according to the present invention comprises a reference oscillation circuit 1 having a constant frequency and a finger or hand approaching with substantially the same time constant as this. A detection oscillation circuit 2 whose frequency changes due to a capacitance change due to the above, a detection electrode connected to the detection oscillation circuit 2 which detects a capacitance change due to the approach of a finger or a hand, and a reference oscillation circuit 1 A circuit for converting the difference between the oscillation frequencies of the detection oscillation circuit 2 into a voltage and a comparison circuit for comparing the voltage with a reference value are provided, which are incorporated inside a housing of a device or the like.

In order to improve the detection accuracy, the reference oscillation circuit 1 and the detection oscillation circuit 2 are mounted on a circuit board by components, arrangement,
It is characterized in that wiring and the like are equalized. In addition, a detection electrode is incorporated into the case at least 10 mm from the outside of the case so that the case can be detected even when the case plate is thick or curved.

[0007]

FIG. 1 shows a basic configuration of the present invention. The present invention comprises two oscillation circuits, a reference oscillation circuit 1 having a fixed frequency and a detection oscillation circuit 2 having substantially the same time constant as the reference oscillation circuit. Has a detection electrode for detecting The detection electrode is not particularly limited, such as a double circular type, a double rectangular type, a parallel electrode, and a comb type.

The two oscillating circuits have substantially the same frequency if no finger or hand approaches, but if a finger or hand having a large relative permittivity approaches, the distance between the electrodes of the detecting electrode of the detecting oscillating circuit 2 will increase. The capacitance increases, and the frequency of the detection oscillation circuit 2 decreases.

The difference between the frequencies is obtained, and noise is removed through a low-pass filter. Then, the frequency is converted into a voltage by the conversion circuit, and the voltage is compared with the threshold by the comparison circuit. If the voltage is larger than the threshold, a signal indicating that a finger or a hand approaches is output.

The two oscillating circuits are set to have substantially the same frequency unless a finger or a hand approaches, but the smaller the set frequency difference, the larger the rate of frequency change due to the approach of the finger can be set, and sufficient detection can be performed. Sensitivity can be provided.

It is also undesirable that the frequency difference between the two oscillation circuits greatly changes when the temperature changes. Therefore, the components of both oscillation circuits should be those having the same characteristics, and the component arrangement and wiring routing should be the same.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A detection electrode for changing the capacitance by the approach of a finger is a double rectangular electrode of 20 mm on each side as shown in FIG. 2, and an internal electrode and an external electrode are respectively connected to a lead terminal for connection. It is connected to. The opposite surface of the electrode was entirely made of copper foil for noise suppression.

As the oscillation circuit, a Colpitts-type LC oscillation circuit including an inversion element as shown in FIG. 3 is used, and the oscillation frequency is 10 MHz.
The detection electrode C, which is set to z and whose capacitance changes when a finger or hand is brought close, is connected in parallel to a capacitor C1 on the input side of the inverting element.

The frequency difference was determined by a frequency difference calculation circuit using exclusive OR from two oscillation circuits. The frequency to voltage conversion circuit uses a monostable multivibrator,
The one-shot pulse output was integrated to obtain a voltage. The change width of the voltage was adjusted by the one-shot pulse output width. The voltage was connected to a comparator circuit with an appropriate threshold, and to an output circuit.

The circuits excluding the detection electrodes were integrated on a single circuit board, components were collectively mounted on one surface, and the other surface was a copper foil surface except for wiring. The detection electrode substrate and the circuit board were integrated with a connection component such that the copper foil surface of the detection electrode substrate faced the surface of the circuit board on which the components were not mounted.

As shown in FIG. 4, the integrated detection electrode substrate and circuit board were placed on a 3 mm-thick polycarbonate plate at a distance. A finger touched or approached the polycarbonate plate from the side where the electrode substrate for detection was not installed with the polycarbonate plate interposed, and the detection range was confirmed.

When the distance between the polycarbonate plate and the electrode substrate for detection was 10 mm, the change in the frequency was 10% or more and the operation was satisfactory. Thereafter, the operating range was confirmed by increasing the distance, but the operation was performed even when the distance was 30 mm.

[0018]

The present invention is composed of two oscillation circuits, a reference oscillation circuit 1 and a detection oscillation circuit 2, and the detection accuracy can be improved by equalizing parts, arrangement, wiring routing, etc. on the circuit board, Capacitive proximity switch that can be built into the housing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a detection electrode diagram according to one embodiment.

FIG. 3 is an oscillation circuit diagram according to one embodiment.

FIG. 4 is a mounting diagram of a detection electrode substrate according to one embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Reference oscillation circuit 1 12 Detection oscillation circuit 2 13 Detection electrode 14 Frequency difference calculation circuit 15 Low-pass filter 16 Frequency voltage conversion circuit 17 Comparison circuit 18 Threshold voltage 19 Output circuit 21 Internal electrode 22 External electrode 23 Internal electrode Lead terminal 24 External electrode lead terminal 31 Capacitor C1 on the input side of the inverting element 32 Capacitor C2 on the output side of the inverting element 33 Detection electrode C 41 Detection electrode substrate 42 Circuit board 43 Connecting component 44 Detection electrode surface 45 Polycarbonate plate 46 fingers

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F063 AA50 BA29 DA01 DA05 EB02 HA04 LA04 LA05 LA30 5G046 AA07 AB03 AC21 AD21 AD23 AE02 5J050 AA37 AA47 BB22 CC00 EE34 EE36 EE40 FF30

Claims (3)

[Claims]
1. A reference oscillation circuit 1 having a constant frequency, a detection oscillation circuit 2 having substantially the same time constant and changing in frequency due to a capacitance change due to the approach of a finger or hand, and an approach of a finger or hand. A detection electrode connected to a detection oscillation circuit 2 for detecting a change in capacitance caused by the above, a circuit for converting an oscillation frequency difference between the reference oscillation circuit 1 and the detection oscillation circuit 2 into a voltage, and a reference value for the voltage. And a comparison circuit for comparison with the above, and incorporated in the inside of a housing of a device or the like.
2. The reference oscillation circuit 1 and the detection oscillation circuit 2
2. The capacitive proximity switch according to claim 1, wherein components, arrangement, wiring routing, and the like are equalized on the circuit board.
3. The electrostatic capacitance proximity switch according to claim 1, wherein the detection electrode is incorporated into the housing at least 10 mm from the outside of the housing.
JP2000275043A 2000-09-11 2000-09-11 Electrostatic capacity type proximity switch Pending JP2002084179A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000275043A JP2002084179A (en) 2000-09-11 2000-09-11 Electrostatic capacity type proximity switch

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000275043A JP2002084179A (en) 2000-09-11 2000-09-11 Electrostatic capacity type proximity switch

Publications (1)

Publication Number Publication Date
JP2002084179A true JP2002084179A (en) 2002-03-22

Family

ID=18760722

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000275043A Pending JP2002084179A (en) 2000-09-11 2000-09-11 Electrostatic capacity type proximity switch

Country Status (1)

Country Link
JP (1) JP2002084179A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006253763A (en) * 2005-03-08 2006-09-21 Rohm Co Ltd Comparator circuit, capacitance voltage conversion circuit utilizing the same, and electronic apparatus
JP2006304077A (en) * 2005-04-22 2006-11-02 Toshiba Consumer Marketing Corp Touch switch and refrigerator
JP2009005259A (en) * 2007-06-25 2009-01-08 Stanley Electric Co Ltd Electrostatic capacity detecting circuit
JP2016130656A (en) * 2015-01-13 2016-07-21 センサテック株式会社 Capacitance sensor
JP2016540324A (en) * 2013-10-07 2016-12-22 サイプレス セミコンダクター コーポレーション Detection and identification of touches of different sized conductive objects on capacitive buttons

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006253763A (en) * 2005-03-08 2006-09-21 Rohm Co Ltd Comparator circuit, capacitance voltage conversion circuit utilizing the same, and electronic apparatus
JP2006304077A (en) * 2005-04-22 2006-11-02 Toshiba Consumer Marketing Corp Touch switch and refrigerator
JP2009005259A (en) * 2007-06-25 2009-01-08 Stanley Electric Co Ltd Electrostatic capacity detecting circuit
JP2016540324A (en) * 2013-10-07 2016-12-22 サイプレス セミコンダクター コーポレーション Detection and identification of touches of different sized conductive objects on capacitive buttons
JP2016130656A (en) * 2015-01-13 2016-07-21 センサテック株式会社 Capacitance sensor

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