DE102009000966A1 - Oscillatory pressure sensor - Google Patents

Oscillatory pressure sensor

Info

Publication number
DE102009000966A1
DE102009000966A1 DE200910000966 DE102009000966A DE102009000966A1 DE 102009000966 A1 DE102009000966 A1 DE 102009000966A1 DE 200910000966 DE200910000966 DE 200910000966 DE 102009000966 A DE102009000966 A DE 102009000966A DE 102009000966 A1 DE102009000966 A1 DE 102009000966A1
Authority
DE
Germany
Prior art keywords
sensor
switch element
characterized
element according
preceding
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.)
Withdrawn
Application number
DE200910000966
Other languages
German (de)
Inventor
Kai Huck
Günther Irlbacher
Achim Mielke
Hans-Jürgen Dr. Schreiner
Peter Winter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GROHE AG, DE
IRLBACHER BLICKPUNKT GLAS GMBH, DE
CeramTec GmbH
Original Assignee
IRLBACHER BLICKPUNKT GLAS GmbH
CeramTec GmbH
Grohe AG
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
Priority to DE102008000378.6 priority Critical
Priority to DE102008000378 priority
Application filed by IRLBACHER BLICKPUNKT GLAS GmbH, CeramTec GmbH, Grohe AG filed Critical IRLBACHER BLICKPUNKT GLAS GmbH
Priority to DE200910000966 priority patent/DE102009000966A1/en
Publication of DE102009000966A1 publication Critical patent/DE102009000966A1/en
Application status is Withdrawn legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making or -braking
    • H03K17/94Electronic switching or gating, i.e. not by contact-making or -braking characterised by the way in which the control signal is generated
    • H03K17/96Touch switches
    • H03K17/964Piezo-electric touch switches

Abstract

The invention relates to a sensor (1) or a switch element with at least one oscillator (2) which is oscillated by an oscillator circuit by an AC voltage (3), wherein the oscillation behavior of the oscillator (2) changes when pressurized and this change is detectable as damping of the vibration and further processed as an output signal. So that the sensor or the switch element on the one hand from environmental influences such. B. rain or snow is protected and on the other hand is insensitive to frequency shifts, the invention proposes that the sensor (1) or the switch element on the back (5) of a mechanically rigid medium (4) is arranged and the pressurization on the opposite front ( 6) passes through the mechanically rigid medium (4) and the oscillator circuit oscillates the oscillator (2) with a continuous change in frequency between an initial frequency and a final frequency.

Description

  • The The invention relates to a sensor or a switching element with at least an oscillator, that of an oscillator circuit by an AC voltage is vibrated, whereby the vibration behavior of the oscillator when pressurized changes and this change as attenuation of the vibration detectable and as an output signal is processable.
  • was standing the technique is to touch a z. B. on glass means to detect a capacitive sensor. Disadvantage of this method is that liquids such. For example, water is not safe from human tissue to distinguish.
  • A generic prior art is in the DE 10 2005 061 754 A1 described. Here it is proposed to connect a piezoelectric vibrator with the sensor surface, coupled into an oscillator circuit and put into vibrations, so that a touch or pressing an operator body part to the sensor surface to a change in the vibration behavior (due to the damping and increasing the resonant Mass) leads and this change can be detected by means of an evaluation circuit coupled to the oscillator circuit. The change of the vibration behavior by contact with the operator body part should be easy and safe to evaluate. The piezoelectric transducer is mounted on a support (glued, for example). On an opposite side of the piezoelectric vibrator is covered by a thin plastic film or plastic wall, the top of the sensor surface of the actuating point Figuret.
  • Of the Invention is based on the object, a sensor or a switching element according to the preamble of claim 1 educate so that he on the one hand before environmental influences, such. As rain or snow is protected and on the other hand insensitive to frequency shifts is. In addition, a sensor signal is to be generated, the it allows a finger pressure on a stiff plate (eg glass plate) preferably without sensitivities and localized by to detect the back of the plate.
  • According to the invention this object is achieved in that the sensor or the Switch element on the back of a mechanically stiff medium is arranged and the pressurization on the opposite Front through the mechanically rigid medium through and the oscillator circuit the oscillator with a continuous Frequency change between an initial frequency and a End frequency vibrated. This is the sensor or the switch element on the one hand from environmental influences, such as z. As rain or snow is protected and is on the other hand insensitive against frequency shifts. In addition, a finger pressure on a stiff plate (eg glass plate) without cross sensitivities and localized detected from the back of the plate become.
  • In an inventive embodiment, the vibration is electromechanical generated. In another embodiment, the vibration of the at least one oscillator electromechanically generated and the damping measured with a piezoelectric element. Again in another inventive Design, the vibration is generated by means of piezoelectric element and the attenuation measured with a second piezoelectric element.
  • In In a preferred embodiment, the vibration by means of piezoelectric element generated and the attenuation measured with the same piezoelectric element.
  • In inventive design have the piezo elements used a piezoelectric charge constant> 10 pC / N, preferably> 160 pC / N and particularly preferably> 200 pC / N. With These charge constants were able to achieve the best results.
  • In inventive design have the piezo elements used a high electromechanical quality of> 50, preferably> 100 and particularly preferably> 500.
  • Prefers is the mechanically rigid medium made of glass or metal, as these Materials best forward the pressurization to the sensor.
  • Prefers the pressure is applied by finger pressure. In this embodiment speaks one therefore from a finger pressure sensor.
  • In a particular embodiment is the sensor or the Switch element with at least one other sensor different operating principle coupled (eg capacitive sensors, infrared sensors, etc). hereby an erroneous signal is almost impossible.
  • Prefers All sensors consist of a common ceramic carrier material and these are through slots in the substrate and at least separated on one side in the contacting surfaces.
  • In a special embodiment, a glass pane is arranged between the piezoelement and the mechanically stiff medium. The glass pane can be used, for example, to couple light to the side and thus a Be illumination of the pressure point or the sensor surface.
  • Prefers For example, the sensor or switch element is used as a finger pressure sensor.
  • object The invention thus provides a finger pressure sensor based on a piezoelectric oscillator, which allows one Touch through a mechanically rigid medium to detect and thus trigger a switching signal, for example.
  • On the back of a mechanically stiff medium, glass or Metal is a piezoelectric element applied, for example glued, which is excited by means of an electrical signal so that at the sensor location or sensor surface an electromechanical Resonance results. The resonance is changed by pressure loading so that results in a detectable signal change. Being represented For example, this signal change may be due to the amount of complex AC resistance in unloaded or loaded Status.
  • Of the Sensor or the switch element is by the mechanically rigid Medium insensitive to wetting with water or other media and that is its selectivity given to a compressive stress.
  • following the invention will become more apparent by means of examples and figures described.
  • Example 1:
  • On a glass plate as a mechanically stiff medium 4 (please refer 1 ) with a thickness of 4 mm will be on the back 5 a piezo element 7 as piezoceramic disc with a diameter of 16 mm and a thickness of 0.8 mm as an oscillator 2 applied. By means of an alternating voltage (U ~) three becomes the oscillator 2 or the sensor 1 vibrated and measured the complex AC resistance. With the reference number three is flat rate in addition to the AC voltage and the associated oscillator circuit referred to. In order to make the system insensitive to frequency shifts, the frequency at which the piezo element is switched off 7 is excited to oscillate continuously changed between an initial frequency and a final frequency. In principle, any material with sufficient piezoelectric activity (piezoelectric charge constant d33> 10 pC / N) is suitable as the piezoelectric material. Use is in Example 1 z. B. a piezoelectric soft material with a d33 of about 450 pC / N and a Q of 90.
  • This results in the 2 shown behavior of the magnitude of the complex AC resistance as a function of frequency. The illustration also shows that it is possible to make a clear distinction between wetting with a medium (here water) and damping with pressure (here finger pressure). The sensitive area is typically in a circle of about 0.8 to 1 cm radius at this geometry ratios, while outside of this sensitive area with a radius greater than 1 to 1.2 cm no attenuation and thus no cross-sensitivity to adjacent sensor surfaces / styli is present.
  • Example 2:
  • On a glass plate, as a mechanically stiff medium 4 , with a thickness of z. B. 4 mm will be on the back 5 a small pane of glass 8th glued on (thickness eg 2.8 mm and diameter 15.9 mm) on which a piezoceramic disc as an oscillator 2 with a diameter of 12 mm and a thickness of 2 mm is applied (see three ). With the reference number 6 is the front side designated, which serves as a sensor surface. By means of an alternating voltage three becomes the oscillator 2 or the piezo disk 7 vibrated and measured the complex AC resistance. In order to make the system insensitive to frequency shifts, the frequency is continuously varied between an initial frequency and a final frequency.
  • The glass pane 8th can be used, for example, to couple light laterally to make an illumination of the pressure point.
  • Of the sensitive area lies with these geometric relationships typically in a circle of about 0.6 to 0.9 cm radius while outside this sensitive area with a radius greater than 1 to 1.2 cm no damping takes place and thus also no cross-sensitivity to adjacent sensor areas / button fields is present.
  • When Piezoelectric material is in principle suitable for any material with sufficient piezoelectric activity (piezoelectric Charge constant d33> 10 pC / N), but particularly preferably is a piezoelectric Hard material with low damping and high electromechanical Quality. Use is z. A material with a d33 of 240 pC / N and a Q of 1000. The change in the amount of the complex alternating current resistance then typically at least factor 2 to 4.
  • QUOTES INCLUDE IN THE DESCRIPTION
  • This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.
  • Cited patent literature
    • DE 102005061754 A1 [0003]

Claims (13)

  1. Sensor ( 1 ) or switch element with at least one oscillator ( 2 ), which is controlled by an oscillator circuit by an AC voltage ( three ) is vibrated, wherein the oscillatory behavior of the oscillator ( 2 ) changes upon pressurization and this change is detectable as an attenuation of the oscillation and further processed as an output signal, characterized in that the sensor ( 1 ) or the switch element on the back ( 5 ) of a mechanically stiff medium ( 4 ) is arranged and the pressurization on the opposite front ( 6 ) by the mechanically stiff medium ( 4 ) is carried out and the oscillator circuit the oscillator ( 2 ) is oscillated with a continuous frequency change between an initial frequency and a final frequency.
  2. Sensor or switch element according to claim 1, characterized characterized in that the vibration is generated electromechanically.
  3. Sensor or switch element according to claim 1 or 2, characterized in that the oscillation of the at least one oscillator ( 2 ) produced electromechanically and the damping with a piezoelectric element ( 7 ) is measured.
  4. Sensor or switch element according to one of the preceding claims, characterized in that the vibration by means of piezoelectric element ( 7 ) is generated and the attenuation is measured with a second piezoelectric element.
  5. Sensor or switch element according to one of the preceding claims, characterized in that the vibration by means of piezoelectric element ( 7 ) is generated and the damping with the same piezoelectric element ( 7 ) is measured.
  6. Sensor or switch element according to one of the preceding claims, characterized in that the piezo elements used ( 7 ) have a piezoelectric charge constant> 10 pC / N, preferably> 160 pC / N and particularly preferably> 200 pC / N.
  7. Sensor or switch element according to one of the preceding claims, characterized in that the piezo elements used ( 7 ) have a high electromechanical quality of> 50, preferably> 100 and particularly preferably> 500.
  8. Sensor or switch element according to one of the preceding claims, characterized in that the mechanically rigid medium ( 4 ) consists of glass or metal.
  9. Sensor or switch element according to one of the preceding Claims, characterized in that the pressurization is applied by finger pressure.
  10. Sensor or switch element according to one of the preceding claims, characterized in that the sensor ( 1 ) or the switch element is coupled to at least one further sensor other functional principle (eg, capacitive sensors, infrared sensors, etc).
  11. Sensor or switch element according to one of the preceding Claims, characterized in that all sensors off consist of a common ceramic carrier material and these through slots in the carrier material and at least on one side are separated from each other in the contacting surfaces.
  12. Sensor or switch element according to one of the preceding claims, characterized in that between the piezo element ( 7 ) and the mechanically stiff medium ( 4 ) a glass sheet ( 8th ) is arranged.
  13. Using a sensor ( 1 ) or switch element according to one of the preceding claims as a finger pressure sensor.
DE200910000966 2008-02-22 2009-02-18 Oscillatory pressure sensor Withdrawn DE102009000966A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DE102008000378.6 2008-02-22
DE102008000378 2008-02-22
DE200910000966 DE102009000966A1 (en) 2008-02-22 2009-02-18 Oscillatory pressure sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE200910000966 DE102009000966A1 (en) 2008-02-22 2009-02-18 Oscillatory pressure sensor

Publications (1)

Publication Number Publication Date
DE102009000966A1 true DE102009000966A1 (en) 2009-08-27

Family

ID=40578229

Family Applications (1)

Application Number Title Priority Date Filing Date
DE200910000966 Withdrawn DE102009000966A1 (en) 2008-02-22 2009-02-18 Oscillatory pressure sensor

Country Status (2)

Country Link
DE (1) DE102009000966A1 (en)
WO (1) WO2009103729A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005061754A1 (en) 2005-12-21 2007-06-28 Huf Hülsbeck & Fürst Gmbh & Co. Kg Sensor arrangement for detecting the pressing of an operator body part to a sensor surface

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH681670A5 (en) * 1991-03-05 1993-04-30 Dynalab Ag
TW241352B (en) * 1994-03-30 1995-02-21 Whitaker Corp Reflective mode ultrasonic touch sensitive switch
DE19528821A1 (en) * 1995-08-05 1997-02-06 Carmen Diessner Pushbutton e.g. for computer data input keyboard - has glass or acrylic glass pushbutton with engraved symbol on underside that is illuminated by bulb
US7091886B2 (en) * 2004-06-09 2006-08-15 Lear Corporation Flexible touch-sense switch

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005061754A1 (en) 2005-12-21 2007-06-28 Huf Hülsbeck & Fürst Gmbh & Co. Kg Sensor arrangement for detecting the pressing of an operator body part to a sensor surface

Also Published As

Publication number Publication date
WO2009103729A1 (en) 2009-08-27

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Legal Events

Date Code Title Description
8127 New person/name/address of the applicant

Owner name: CERAMTEC GMBH, 73207 PLOCHINGEN, DE

Owner name: GROHE AG, 58675 HEMER, DE

Owner name: IRLBACHER BLICKPUNKT GLAS GMBH, 92539 SCHOENSE, DE

R081 Change of applicant/patentee

Owner name: GROHE AG, DE

Free format text: FORMER OWNER: CERAMTEC AG, GROHE AG, IRLBACHER BLICKPUNKT GLAS GMBH, , DE

Effective date: 20110208

Owner name: IRLBACHER BLICKPUNKT GLAS GMBH, DE

Free format text: FORMER OWNER: CERAMTEC AG, GROHE AG, IRLBACHER BLICKPUNKT GLAS GMBH, , DE

Effective date: 20110208

Owner name: CERAMTEC GMBH, DE

Free format text: FORMER OWNER: CERAMTEC AG, GROHE AG, IRLBACHER BLICKPUNKT GLAS GMBH, , DE

Effective date: 20110208

Owner name: IRLBACHER BLICKPUNKT GLAS GMBH, DE

Free format text: FORMER OWNERS: CERAMTEC AG, 73207 PLOCHINGEN, DE; GROHE AG, 58675 HEMER, DE; IRLBACHER BLICKPUNKT GLAS GMBH, 92539 SCHOENSEE, DE

Effective date: 20110208

Owner name: GROHE AG, DE

Free format text: FORMER OWNERS: CERAMTEC AG, 73207 PLOCHINGEN, DE; GROHE AG, 58675 HEMER, DE; IRLBACHER BLICKPUNKT GLAS GMBH, 92539 SCHOENSEE, DE

Effective date: 20110208

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Free format text: FORMER OWNERS: CERAMTEC AG, 73207 PLOCHINGEN, DE; GROHE AG, 58675 HEMER, DE; IRLBACHER BLICKPUNKT GLAS GMBH, 92539 SCHOENSEE, DE

Effective date: 20110208

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