US3638052A - Electroacoustic transducers of the bilaminar flexural vibrating type - Google Patents
Electroacoustic transducers of the bilaminar flexural vibrating type Download PDFInfo
- Publication number
- US3638052A US3638052A US10748A US3638052DA US3638052A US 3638052 A US3638052 A US 3638052A US 10748 A US10748 A US 10748A US 3638052D A US3638052D A US 3638052DA US 3638052 A US3638052 A US 3638052A
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- United States
- Prior art keywords
- diaphragm
- disc
- periphery
- diameter
- transducer
- 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.)
- Expired - Lifetime
Links
- 239000000919 ceramic Substances 0.000 claims description 22
- 230000002093 peripheral effect Effects 0.000 claims description 8
- 238000007789 sealing Methods 0.000 claims description 8
- 229910052782 aluminium Inorganic materials 0.000 claims description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 7
- 239000004020 conductor Substances 0.000 claims description 3
- 230000005855 radiation Effects 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 230000013011 mating Effects 0.000 abstract 1
- 230000035945 sensitivity Effects 0.000 description 7
- 238000006073 displacement reaction Methods 0.000 description 5
- 239000004593 Epoxy Substances 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 239000004568 cement Substances 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000004512 die casting Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002991 molded plastic Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
- G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
- G10K9/122—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using piezoelectric driving means
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R17/00—Piezoelectric transducers; Electrostrictive transducers
Definitions
- FRANK MASSA "Hay- PATH-HEB JAHZSGR 3538352 sum-a nr 2 B A INVENTOR.
- FLOOR i FRANK MAssA l ELECTROACOUSTIC TRANSDUCERS OF THE BILAMINAR FLEXURAL VIBRATING TYPE This is a continuation-in-part of my copending' application Ser. No. 859,677, filed Sept. 22, 1969, entitled ELEC- TROACOUSTIC TRANSDUCER, now U.S. Pat. No. 3,578,995, and assigned to the assignee of this invention;
- This invention relates to electroacoustic transducers and more particularly to electroacoustic transducers adapted for radiating uniformly distributed fields of sound over specified areas.
- While the invention may find use in many different environmerits, it has special value as a transducer for use in electroacoustic burglar alarm systems. Among other things, this means that the sound field must be predictably uniform throughout a specified area. These transducers must be relatively low cost devices, which have a high degree of reliability, and do not attract an undue amount of attention.
- an object of this invention is to improve the perfonnance characteristics of an electroacoustic transducer designed for operating in air.
- Another object of this invention is to provide a vibratile diaphragm which produces a specified radiation pattern at a specific operating frequency.
- a further object of this invention is to provide a simple diaphragm assembly which also acts asthe closure of an open end of a rigid housing structure.
- Yet another object of this invention is to provide a vibratile diaphragm which operates in a desired overtone resonance mode when it is driven at a specified frequency.
- a still further object of this invention is to provide a piezoelectric ceramic disc with an increased sensitivity.
- avibratile disc driven by a piezoelectric transducer.
- the disc is made to vibrate in a complex mode of vibrations.
- the modes are selected to provide a sound field with an energy distribution which is more uniformlyv controlled over a specified area than was hitherto available out of comparable devices.
- FIG. 1 is a cross-sectional view of a transducer assembly incorporating one embodiment of this'invention
- FIG. 2 is a plan view of the bottom of the transducer taken along the line 2-2 of FIG. 1;
- FIG. 3 is a plan view of a bilaminar diaphragm assembly taken along line 3-3 of FIG. 1;
- FIG. 4 is a plan view of a second embodiment of a bilaminar diaphragm assembly which may be substituted for the diaphragm assembly of FIG. 3;
- FIG. 5 is a cross-sectional view of the diaphragm taken along the line 55 of FIG. 4;
- FIG. 6 is a schematic representation of an edge mounted diaphragm in its rest position as shown in FIG. 2;
- FIG. 7 schematically represents the peak amplitude when it is driven at its fundamental resonance frequency
- FIG. 8 schematically illustrates the peak amplitude displacement of the diaphragm, when it is driven at its first overtone, nodal circle, resonance frequency
- FIG. 9 graphically illustrates the directional radiation pattern obtained from a diaphragm operating in .its overtone resonance mode as illustrated in FIG. 8;
- FIG. 10 illustrates the improved uniformity of a sound field extending across a floor area in the vicinity of a ceiling mounted transducer having the improved radiation pattern illustrated in FIG. 9.
- the transducer is. enclosed in a generally circular, somewhat tubular housing (FIG. 1) structure having a rigid wall portion terminated at its opposite ends in circular openings.
- Housing 20 may be fabricated from molded plastic 'or a die casting of zinc or aluminum, for example.
- the major elements in the housing 20 are a thin metal diaphragm or disc housing and the periphery of the circular diaphragm disc 21-.
- This attachment may be made by epoxy, or any other suitable cement, bonding the periphery of the diaphragm disc to the rim portion 25
- a ring-shaped member 26 may be cemented with epoxy, for example, tothe outer edge of the diaphragm disc 26 to provide additional rigid support to the area.
- The. periphery of the diaphragm is thus made relativelystiff, as
- FIG. 3 shows one embodiment of a bilaminar diaphragm assembly. More particularly, a piezoelectric disc 30 is cemented to the center of the diaphragm 21 with a suitable rigid cement, such as epoxy. Any one of many well-known polarized ceramics may be used at this point. The piezoelectric disc 30 covers less than one-half the diaphragm area, in the construction of FIGS. 1 and 3. The unattached surface of the ceramic disc 30 is provided with two divided electrodes 31 and 32. The cemented side of the ceramic disc 30 is provided with a single electrode extending over the entire surface. The disc 30 is then polarized, as described in U.S. Pat. No. 2,967,957.
- Electrodes 34 and 35 are connected to the electrode surfaces 31 and 32, as by soldering, for example.
- the leads 34 and 35 are then connected to the electronic components sche matically illustrated by the box 22.
- the wires 36 are connected between electronics 22 and the terminal pins 37 which make up the plug 23. This plug provides for establishing external connections to the transducer assembly.
- the pin terminals are fastened to an electrical insulating baseplate 39, such as plastic. Finally, the outer periphery of the baseplate 39 is cemented to seal one open end of the housing 20.
- the arrangement of these pin terminals may be seen in FIG. 2, where a certain nonsymmetry enables a polarization of the plug-in unit. This precludes plugging the pin tenninals 37 into the wrong socket terminals, not shown.
- FIGS. 4 and 5 show-a second embodiment of a bilaminar diaphragm assembly.
- a circular plate diaphragm 40 is rigidly bonded to a polarized ceramic disc 41, again by using epoxy or other suitable cement.
- the ceramic'disc covers practically the entire area of the diaphragm.
- Two separated concentric electrode surfaces 42 and 43 are provided on the exposed surface of the ceramic disc. The separation between the electrodes 42, 43 is placed in the region of the nodal diameter for the first overtone resonance mode of the mounted bilaminar disc.
- FIGS. 6-10 are helpful for an understanding of the design criteria for the bilaminar diaphragm assemblies, illustrated in FIG. 3 or FIG. 4.
- FIG. 6 shows a disc or circular plate, of diameter D and thickness t, clamped at its periphery.
- diameter of the diaphragm is determined by the desired frequency of operation and the desired resonance mode for producing the improved directional pattern illustrated in FIG.
- the fundamental resonant frequency of the plate is proportional to E Youngs modulus, and p density of the material.
- D Diaphragm diameter
- t diameter thickness.
- the ratio e/p should be a maximum.
- p should also be a minimum.
- aluminum best satisfies these requirements; therefore, it is the preferred metal for the diaphragm material.
- FIG. 7 illustrates the deflection of a clamped disc operating at its fundamental resonance mode.
- the curve is uniform along a diameter of a clamped circular plate diaphragm.
- the displacement is in the same phase over the entire diaphragm surface.
- FIG. 8 illustrated the deflection of a clamped disc when operating at its first overtone nodal circle resonance frequency. There is a reverse bend in the curve which results along the diameter of the diaphragm. This overtone frequency occurs at approximately 3.9 times the fundamental resonance frequency.
- the displacement of the center portion of the diaphragm has a phase which is opposite to the phase of the displacement of the outer portion of the diaphragm.
- the solid curve 50 shows the type of directional radiation pattern, which is obtained from aclamped disc when the diaphragm is operating in the overtone mode illustrated in FIG. 8. This curve assumes that the diaphragm lies in the plane defined by the line 9090. It is desirable to use this higher resonance mode of vibration, at the operating frequency of the transducer, since an improved directional radiation pattern is obtained from this operational mode.
- the curve 50 is derived from the sum of the radiation pattern 51 which is generated by the center portion of diaphragm and the pattern 52 which is generated by the outer annular portion of the diaphragm.
- the area of reduced sensitivity lies along the line which is perpendicular to the diaphragm.
- the angle 0 indicates the axis of maximum sensitivity which generally corresponds to the major axis of the secondary lobes 53. Plus and minus signs indicate the relative phases of the sound pressure transmitted into the various zones defined by the primary and secondary lobes of the component directional patterns 51 and 52.
- the pattern 51 is typical of a pattern produced from a small circular diaphragm having a diameter which is less than the wavelength of sound at the frequency of operation.
- the pattern 52 is typical of a pattern produced from a vibrating annular shaped diaphragm having a diameter which is greater than the wavelength of sound at the frequency of operation.
- the location of the region of maximum response is such that the angle 0 is approximately equal to 90".
- the ratio D/lt is larger than 4
- the location of the region of maximum response is located where 0 is less than 30.
- An undesirable ragged directional response curve results in the region where 0 is greater than 45. Therefore, to produce a satisfactory directional pattern with a smoothly increased sensitivity in the region extending 30 beyond the normal axis of the diaphragm, the preferred diameter of the diaphragm is within the approximate range 1% to 4 times the wavelength of sound at the operating frequency.
- the diameter of the ceramic disc 30 must be less than k the diameter of the metal diaphragm 21. If the ceramic disc is larger, the entire ceramic will not be stressed in the same phase during each displacement cycle of the diaphragm.
- the diameter of the center electrode 42 must be less than A the diameter of the diaphragm 40.
- the separation between the electrode surfaces 42 and 43 should be in the reverse curve region R of the nodal diameter for the overtone mode of operation illustrated in FIG. 8.
- FIG. 10 illustrates an advantage of the improved directional pattern.
- the improved directional pattern 50 indicates a higher intensity level along the maximum sensitivity axis 0 to a distant position A, as compared to an intermediate position B.
- the higher intensity along the axis to position A compensates for the greater distance between the transducer 20 and the position A.
- This conventional pattern fails to achieve the desirable objective of equalizing the sound intensity level over the area. 1
- An electroacoustic transducer for operating in the air, said transducer comprising a housing structure including a rigid peripheral wall section surrounding an opening having a circular rim section, means for sealing said opening comprising a circular diaphragm for operating in the flexiiral mode rigidly clamped at its periphery to said circular rim section, said clamped diaphragm having a diameter between 1% and 4 times the wavelength of sound at the operating frequency and being characterized in that the length of its periphery is more than 20 times greater than its thickness, said thickness being substantially uniform and unvarying throughout the entire area defined by said clamped periphery, transducer means including a piezoelectric disc having a diameter which is less than one-half the diameter of the diaphragm rigidly bonded to one side of said clamped diaphragm, means for driving said diaphragm at the resonant flexural mode frequency, and means comprising electrical conductors attached to said piezoelectric disc for imparting driving signals thereto
- An electroacoustic transducer comprising a housing structure including a rigid peripheral wall section surrounding an opening having a circular rim section, means for sealing said opening comprising a circular aluminum diaphragm rigidly clamped at its periphery to said circular rim section, the periphery of said diaphragm being more than 20 times greater than its thickness, said diaphragm having a diameter exceeding 1% times the wavelength of sound at the operating frequency, transducer means including a polarized ceramic piezoelectric disc rigidly bonded to one side of said diaphragm for vibrating said diaphragm, said disc being less than one-half the diameter of said diaphragm, and two separate spacedapart electrodes mounted on the unbonded side of said disc for imparting driving signals thereto for causing said disc and diaphragm to operate in a flexural mode.
- An electroacoustic transducer comprising a housing structure including a rigid peripheral wall section surrounding an opening having a circular rim section, means for sealing said opening comprising a circular diaphragm rigidly clamped at its periphery to said circular rim section, the periphery of said diaphragm being more than 20 times greater than its thickness, said diaphragm having a diameter exceeding 1% times the wavelength of sound at the operating frequency, transducer means including a polarized ceramic piezoelectric disc rigidly bonded to one side of said diaphragm for vibrating said diaphragm, said disc being less than one-half the diameter of said diaphragm, and two separate spaced apart electrodes mounted on the unbonded side of said disc for imparting driving signals thereto for causing said disc and diaphragm to operate in a flexural mode.
- An electroacoustic transducer comprising a housing v structure including a rigid peripheral wall section surrounding an opening having a circular rim section, means for sealing said opening comprising a circular diaphragm rigidly clamped at its periphery to said circular n'm section, the periphery of said diaphragm being more than 20 times greater than its thickness, said diaphragm having a diameter exceeding W: times the wavelength of sound at the operating frequency, transducer means including a polarized ceramic piezoelectric disc rigidly bonded to one side of said diaphragm for vibrating said diaphragm, said disc being less than one-half the diameter of said diaphragm, and electrical connection making means comprising at least one electrode mounted on the unbonded side of said disc for imparting driving signals thereto for causing said disc and diaphragm to operate in a flexural mode.
Abstract
Description
Claims (7)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US85967769A | 1969-09-22 | 1969-09-22 | |
US1074870A | 1970-02-12 | 1970-02-12 |
Publications (1)
Publication Number | Publication Date |
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US3638052A true US3638052A (en) | 1972-01-25 |
Family
ID=26681547
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10748A Expired - Lifetime US3638052A (en) | 1969-09-22 | 1970-02-12 | Electroacoustic transducers of the bilaminar flexural vibrating type |
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US (1) | US3638052A (en) |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3761956A (en) * | 1970-10-01 | 1973-09-25 | Nittan Co Ltd | Sound generating device |
US3872470A (en) * | 1973-04-18 | 1975-03-18 | Airco Inc | Audible signal generating apparatus having selectively controlled audible output |
US3879726A (en) * | 1972-03-20 | 1975-04-22 | Mallory & Co Inc P R | Audible alarm unit |
US4045695A (en) * | 1974-07-15 | 1977-08-30 | Pioneer Electronic Corporation | Piezoelectric electro-acoustic transducer |
US4188612A (en) * | 1978-05-01 | 1980-02-12 | Teledyne Industries Inc. (Geotech Division) | Piezoelectric seismometer |
US4193010A (en) * | 1976-12-09 | 1980-03-11 | Essex Transducers Corporation | Sensor device using piezoelectric coating subjected to bending |
DE2934663A1 (en) * | 1978-08-28 | 1980-03-13 | American District Telegraph Co | ELECTROACOUSTIC TRANSDUCERS AND DEVICES FOR ADJUSTING THE DIRECTIONAL CHARACTERISTICS, IN PARTICULAR FOR BURGLAR ALARM SYSTEMS |
US4349747A (en) * | 1980-01-30 | 1982-09-14 | Ozen Corp. | Sound response time switch for flowing current for a predetermined period of time |
FR2530108A1 (en) * | 1982-07-12 | 1984-01-13 | Geophysique Cie Gle | Novel hydrophone |
FR2553213A1 (en) * | 1983-10-11 | 1985-04-12 | Saphymo Stel | Leaktight audible alarm device and apparatus comprising it |
US5204907A (en) * | 1991-05-28 | 1993-04-20 | Motorola, Inc. | Noise cancelling microphone and boot mounting arrangement |
WO1999001234A2 (en) * | 1997-06-30 | 1999-01-14 | Robert Bosch Gmbh | Ultrasonic transducer |
EP0930607A2 (en) * | 1998-01-13 | 1999-07-21 | Murata Manufacturing Co., Ltd. | Ultrasonic sensor |
WO2006000494A1 (en) * | 2004-06-29 | 2006-01-05 | Robert Bosch Gmbh | Membrane well for an ultrasonic transducer |
US20060083501A1 (en) * | 2004-10-18 | 2006-04-20 | Mark Segal | Method and apparatus for creating aerial panoramic photography |
US20060185822A1 (en) * | 2004-07-07 | 2006-08-24 | Georgia Tech Research Corporation | System and method for thermal management using distributed synthetic jet actuators |
US20120113758A1 (en) * | 2009-07-23 | 2012-05-10 | Valeo Schalter Und Sensoren Gmbh | Diaphragm and process for producing a diaphragm for an ultrasonic transducer |
Citations (8)
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US2910545A (en) * | 1954-08-30 | 1959-10-27 | Gen Electric | Transducer |
US3222462A (en) * | 1961-09-29 | 1965-12-07 | Siemens Ag | Electroacoustic transducer |
US3271596A (en) * | 1963-11-12 | 1966-09-06 | Boeing Co | Electromechanical transducers |
US3307052A (en) * | 1964-04-06 | 1967-02-28 | Frank W Neilson | Piezoelectric stress gage |
US3321189A (en) * | 1964-09-10 | 1967-05-23 | Edison Instr Inc | High-frequency ultrasonic generators |
US3331970A (en) * | 1964-09-29 | 1967-07-18 | Honeywell Inc | Sonic transducer |
US3380019A (en) * | 1967-01-27 | 1968-04-23 | Navy Usa | Pressure-gradient hydrophone |
US3510698A (en) * | 1967-04-17 | 1970-05-05 | Dynamics Corp America | Electroacoustical transducer |
-
1970
- 1970-02-12 US US10748A patent/US3638052A/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2910545A (en) * | 1954-08-30 | 1959-10-27 | Gen Electric | Transducer |
US3222462A (en) * | 1961-09-29 | 1965-12-07 | Siemens Ag | Electroacoustic transducer |
US3271596A (en) * | 1963-11-12 | 1966-09-06 | Boeing Co | Electromechanical transducers |
US3307052A (en) * | 1964-04-06 | 1967-02-28 | Frank W Neilson | Piezoelectric stress gage |
US3321189A (en) * | 1964-09-10 | 1967-05-23 | Edison Instr Inc | High-frequency ultrasonic generators |
US3331970A (en) * | 1964-09-29 | 1967-07-18 | Honeywell Inc | Sonic transducer |
US3380019A (en) * | 1967-01-27 | 1968-04-23 | Navy Usa | Pressure-gradient hydrophone |
US3510698A (en) * | 1967-04-17 | 1970-05-05 | Dynamics Corp America | Electroacoustical transducer |
Cited By (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3761956A (en) * | 1970-10-01 | 1973-09-25 | Nittan Co Ltd | Sound generating device |
US3879726A (en) * | 1972-03-20 | 1975-04-22 | Mallory & Co Inc P R | Audible alarm unit |
US3872470A (en) * | 1973-04-18 | 1975-03-18 | Airco Inc | Audible signal generating apparatus having selectively controlled audible output |
US4045695A (en) * | 1974-07-15 | 1977-08-30 | Pioneer Electronic Corporation | Piezoelectric electro-acoustic transducer |
US4193010A (en) * | 1976-12-09 | 1980-03-11 | Essex Transducers Corporation | Sensor device using piezoelectric coating subjected to bending |
US4188612A (en) * | 1978-05-01 | 1980-02-12 | Teledyne Industries Inc. (Geotech Division) | Piezoelectric seismometer |
DE2934663A1 (en) * | 1978-08-28 | 1980-03-13 | American District Telegraph Co | ELECTROACOUSTIC TRANSDUCERS AND DEVICES FOR ADJUSTING THE DIRECTIONAL CHARACTERISTICS, IN PARTICULAR FOR BURGLAR ALARM SYSTEMS |
US4228379A (en) * | 1978-08-28 | 1980-10-14 | American District Telegraph Company | Diaphragm type piezoelectric electroacoustic transducer |
US4349747A (en) * | 1980-01-30 | 1982-09-14 | Ozen Corp. | Sound response time switch for flowing current for a predetermined period of time |
FR2530108A1 (en) * | 1982-07-12 | 1984-01-13 | Geophysique Cie Gle | Novel hydrophone |
FR2553213A1 (en) * | 1983-10-11 | 1985-04-12 | Saphymo Stel | Leaktight audible alarm device and apparatus comprising it |
US5204907A (en) * | 1991-05-28 | 1993-04-20 | Motorola, Inc. | Noise cancelling microphone and boot mounting arrangement |
WO1999001234A2 (en) * | 1997-06-30 | 1999-01-14 | Robert Bosch Gmbh | Ultrasonic transducer |
WO1999001234A3 (en) * | 1997-06-30 | 1999-04-22 | Bosch Gmbh Robert | Ultrasonic transducer |
US6465935B1 (en) | 1997-06-30 | 2002-10-15 | Robert Bosch Gmbh | Ultrasonic transducer |
EP0930607A2 (en) * | 1998-01-13 | 1999-07-21 | Murata Manufacturing Co., Ltd. | Ultrasonic sensor |
EP0930607A3 (en) * | 1998-01-13 | 2001-11-21 | Murata Manufacturing Co., Ltd. | Ultrasonic sensor |
EP1265222A1 (en) * | 1998-01-13 | 2002-12-11 | Murata Manufacturing Co., Ltd. | Housing for an ultrasonic sensor with separately prepared cylinder and vibration part |
WO2006000494A1 (en) * | 2004-06-29 | 2006-01-05 | Robert Bosch Gmbh | Membrane well for an ultrasonic transducer |
JP2008504724A (en) * | 2004-06-29 | 2008-02-14 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング | Diaphragm pot for ultrasonic converter |
US20080130416A1 (en) * | 2004-06-29 | 2008-06-05 | Micha Kalbhenn | Diaphragm Cup for an Ultrasonic Transducer |
US7570544B2 (en) | 2004-06-29 | 2009-08-04 | Robert Bosch Gmbh | Diaphragm cup for an ultrasonic transducer |
DE102004031310B4 (en) * | 2004-06-29 | 2017-02-09 | Robert Bosch Gmbh | Diaphragm pot for an ultrasonic transducer |
US20060185822A1 (en) * | 2004-07-07 | 2006-08-24 | Georgia Tech Research Corporation | System and method for thermal management using distributed synthetic jet actuators |
US20060083501A1 (en) * | 2004-10-18 | 2006-04-20 | Mark Segal | Method and apparatus for creating aerial panoramic photography |
US7274868B2 (en) * | 2004-10-18 | 2007-09-25 | Mark Segal | Method and apparatus for creating aerial panoramic photography |
US20120113758A1 (en) * | 2009-07-23 | 2012-05-10 | Valeo Schalter Und Sensoren Gmbh | Diaphragm and process for producing a diaphragm for an ultrasonic transducer |
US9311908B2 (en) * | 2009-07-23 | 2016-04-12 | Valeo Schalter Und Sensoren Gmbh | Diaphragm and process for producing a diaphragm for an ultrasonic transducer |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: TRUSTEES FOR AND ON BEHALF OF THE D.P. MASSA TRUST Free format text: ASSIGN TO TRUSTEES AS EQUAL TENANTS IN COMMON, THE ENTIRE INTEREST.;ASSIGNORS:MASSA, DONALD P.;MASSA, CONSTANCE A.;MASSA, GEORGIANA M.;AND OTHERS;REEL/FRAME:005395/0942 Effective date: 19841223 Owner name: MASSA PRODUCTS CORPORATION, 80 LINCOLN STREET, HIN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:DONALD P. MASSA TRUST;CONSTANCE ANN MASSA TRUST *;GEORGIANA M. MASSA TRUST;AND OTHERS;REEL/FRAME:005395/0954 Effective date: 19841223 Owner name: MASSA PRODUCTS CORPORATION, 280 LINCOLN STREET, HI Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:DONALD P. MASSA TRUST;CONSTANCE ANN MASSA TRUST;ROBERT MASSA TRUST;AND OTHERS;REEL/FRAME:005395/0971 Effective date: 19860612 Owner name: MASSA, DONALD P., COHASSET, MA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STONELEIGH TRUST, THE;REEL/FRAME:005397/0016 Effective date: 19841223 Owner name: DELLORFANO, FRED M. JR. Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STONELEIGH TRUST, THE;REEL/FRAME:005397/0016 Effective date: 19841223 |