Producing Permanently Polarized Dielectric (e.g., Electret, Etc.) Patents (Class 264/436)
  • Patent number: 11433333
    Abstract: The electret-treated sheet includes: a core layer (A) which is a porous film containing at least a thermoplastic resin; a surface layer (X) disposed on one side of the core layer (A); and a back surface layer (Y) disposed on the other side of the core layer (A), the surface layer (X) and the back surface layer (Y) each having a charged outermost surface, wherein the electret-treated sheet has a water vapor permeability coefficient of 0.1 to 2.5 g·mm/m2·24 hr; the core layer (A) has a pore aspect ratio of 5 to 50 and an average pore height of 2.5 to 15 ?m; the surface layer (X) and the back surface layer (Y) each have a thickness of 5 to 200 ?m; and the surface layer (X) includes a heat seal layer (B) including the outermost surface, wherein the heat seal layer (B) has a melting point of 50 to 140° C.
    Type: Grant
    Filed: March 27, 2019
    Date of Patent: September 6, 2022
    Assignee: YUPO CORPORATION
    Inventors: Yutaro Sugamata, Hiroshi Koike, Seiichiro Iida
  • Patent number: 11174569
    Abstract: A method for producing ultrafine fibers of the present invention includes forming an electric field between an discharging nozzle from which a raw resin is discharged and a charging electrode which is disposed apart from the discharging nozzle, and supplying the raw resin which has been heated and melted into the electric field from the discharging nozzle to spin the raw resin. The raw resin is a resin mixture which contains a resin having a melting point and an additive, and satisfies a relation (I) below: A/B?1.0×102??(I) wherein A represents the absolute value (?) of electrical impedance of the raw resin at 50° C., and B represents the absolute value (?) of electrical impedance of the raw resin at a temperature 50° C. higher than a melting point of the raw resin.
    Type: Grant
    Filed: April 7, 2017
    Date of Patent: November 16, 2021
    Assignee: KAO CORPORATION
    Inventors: Naomi Amari, Takehiko Tojo, Koji Saito, Hiroya Suzuki, Keitaro Yoneta, Kenta Mukai
  • Patent number: 8937426
    Abstract: A manufacturing method of polarizing polyvinylidene fluoride (PVDF) piezoelectric film without metalized electrode includes providing a polyvinylidene fluoride (PVDF) piezoelectric film that is stretched into ? phase; providing two glass substrates having an indium tin oxide (ITO) layer respectively, wherein the PVDF piezoelectric film is located between the two glass substrates, and the two ITO layers are coated located separately on top of and below the PVDF piezoelectric film; and imposing a DC electric field onto two ITO layers, wherein the DC electric field of polarization is 400 to 900 kV/cm approximately.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: January 20, 2015
    Assignee: Chung-Yuan Christian University
    Inventors: Yung Ting, Sheuan-Perng Lin, Hariyanto Gunawan
  • Patent number: 8901716
    Abstract: An embodiment of the present invention is a technique to provide a dielectric film material with controllable coefficient of thermal expansion (CTE). A first compound containing a first liquid crystalline component is formed. The first compound is cast into a first film. The first film is oriented in an magnetic or electromagnetic field in a first direction. The first film is cured at a first temperature.
    Type: Grant
    Filed: May 5, 2010
    Date of Patent: December 2, 2014
    Assignee: Intel Corporation
    Inventor: James C. Matayabas, Jr.
  • Patent number: 8820968
    Abstract: A method of manufacturing a wavelength conversion element can control a formation process of a polarization inversion structure with single crystalline magnesium-doped lithium niobate having a congruent composition, and can stably manufacture wavelength conversion elements having high conversion efficiency. The method involves forming periodic electrodes on the +z face of an MgLN substrate and forming an opposite electrode on the ?z face of the MgLN substrate; heat-treating the substrate after forming the periodic electrodes and the opposite electrode; and applying a pulsed electric field between the periodic electrodes and the opposite electrode while holding the MgLN substrate at a temperature of 100° C. or higher. The wavelength conversion element has a polarization inversion structure formed by applying an electric field to a heat-treated MgLN substrate.
    Type: Grant
    Filed: October 10, 2012
    Date of Patent: September 2, 2014
    Assignee: Panasonic Corporation
    Inventor: Hiroyuki Furuya
  • Patent number: 8790567
    Abstract: Provided is an electret having high piezoelectric properties. An electret sheet of the invention is characterized in that it comprises a synthetic resin sheet is electrified by injecting electric charges thereinto, that the synthetic resin sheet comprises two types of synthetic resins incompatible with each other, and that these synthetic resins form a phase separated structure and are cross-linked through a polyfunctional monomer. Therefore, positive and negative charges in an apparently polarized state are present in the interfacial portions between the two types of synthetic resins incompatible with each other. By applying an external force to the electret sheet to deform it, the relative positions of these positive and negative charges are changed, and these changes cause a favorable electrical response. Therefore, the electret sheet has high piezoelectric properties.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: July 29, 2014
    Assignees: Sekisui Chemical Co., Ltd., A School Corporation Kansai University
    Inventors: Kazuho Uchida, Takazumi Okabayashi, Yoshiro Tajitsu
  • Patent number: 8771541
    Abstract: A polymer composite piezoelectric body is obtained by conducting polarization treatment on a composite having piezoelectric particles uniformly mixed by dispersion in a polymer matrix containing cyanoethylated polyvinyl alcohol.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: July 8, 2014
    Assignee: FUJIFILM Corporation
    Inventors: Tetsu Miyoshi, Tsutomu Sasaki, Yukio Sakashita
  • Patent number: 8702885
    Abstract: A method of manufacturing ceramics includes: placing, on a base material, a first slurry in which a metal oxide powder is dispersed; applying a magnetic field to the first slurry to solidify the first slurry, thereby forming an under coat layer made of a first compact; placing, on the under coat layer, a second slurry containing a metal oxide powder constituting the ceramics; applying a magnetic field to the second slurry to solidify the second slurry, thereby forming a second compact to obtain a laminated body of the second compact and the under coat layer; and obtaining the ceramics made of the second compact by removing the under coat layer from the laminated body of the second compact and the under coat layer and then sintering the second compact, or sintering the laminated body of the second compact and the under coat layer and then removing the under coat layer.
    Type: Grant
    Filed: April 15, 2011
    Date of Patent: April 22, 2014
    Assignees: Canon Kabushiki Kaisha, University of Yamanashi
    Inventors: Takanori Matsuda, Tatsuo Furuta, Takayuki Watanabe, Jumpei Hayashi, Nobuhiro Kumada
  • Patent number: 8383010
    Abstract: An active element that is based on an electret emulsion and that comprises particles of pre-polarized electret material as emulsion in neutral liquid and both poles of the particles are colored with different colors. For producing a neutral carrier liquid for the active element liquid fluorine carbon is used. For producing electret material for the active element solid polymerised fluorine carbon or electret wax is used. The active element is used for producing visual matrix displays, indicators, surfaces and surface coatings that change color by the application of a control voltage.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: February 26, 2013
    Assignee: Visitret Displays Ou
    Inventor: Jüri Liiv
  • Publication number: 20120086893
    Abstract: A photo alignment process and a liquid crystal display using the same are provided. The photo alignment process includes the following steps. A photo alignment material layer is formed on a substrate. The photo alignment material layer is irradiated by a linearly polarized light. A surface of the photo alignment material layer is a first plane. A wave vector of the linearly polarized light is a K vector. A second plane is constructed from a normal vector of the first plane and the K vector. A polarization direction of the linearly polarized light is neither perpendicular nor parallel to the second plane.
    Type: Application
    Filed: February 20, 2011
    Publication date: April 12, 2012
    Applicant: CHIMEI INNOLUX CORPORATION
    Inventors: Yao-Jen OU, Hang-Lian LEE, Jian-Cheng CHEN, Bo-Chin TSUEI
  • Patent number: 8153702
    Abstract: The present invention relates to a method of producing an electret material, to a new class of electret materials and to a device comprising such electret materials.
    Type: Grant
    Filed: September 14, 2009
    Date of Patent: April 10, 2012
    Assignee: Sony Corporation
    Inventors: Nikolaus Knorr, Silvia Rosselli, Tzenka Miteva, Gabriele Nelles
  • Patent number: 7799260
    Abstract: A method of poling a ferroelectric sample suitable for use in a fuel injector of an internal combustion engine, the method comprising providing a ferroelectric sample having a stack of ferroelectric layers, wherein adjacent layers are separated by internal electrodes, forming a first group and a second group of electrodes; applying a multiaxial pressure to the ferroelectric sample; and generating an electric field between the first and second group of electrodes to pole the ferroelectric sample. The multiaxial pressure is ideally applied by means of a fluid, and the fluid may be an dielectric fluid or fuel.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: September 21, 2010
    Assignee: Delphi Technologies Holding S.arl
    Inventors: Christopher A. Goat, Michael P. Cooke
  • Patent number: 7771647
    Abstract: A method and apparatus for providing electric microcontact printing is provided. A stamp is brought into contact with the surface of a substrate to provide high resolution features. Aspects of the invention may be used for data storage, microcontact printing, and for other applications requiring high resolution pattern transfer.
    Type: Grant
    Filed: December 11, 2002
    Date of Patent: August 10, 2010
    Assignee: President and Fellows of Harvard College
    Inventors: Heiko O. Jacobs, George M. Whitesides
  • Patent number: 7772747
    Abstract: A piezoelectric film is formed on a substrate by a sputtering technique at a film formation temperature higher than a Curie temperature. An electric field is formed across the piezoelectric film in a direction heading from a surface side of the piezoelectric film toward the substrate side before a temperature of the piezoelectric film having been formed falls to a temperature lower than the Curie temperature, polarization processing being caused to begin by the formation of the electric field across the piezoelectric film. The temperature of the piezoelectric film is allowed to fall to a temperature lower than the Curie temperature in the state in which the electric field is being formed.
    Type: Grant
    Filed: March 23, 2009
    Date of Patent: August 10, 2010
    Assignee: Fujifilm Corporation
    Inventors: Takamichi Fujii, Ryuji Tsukamoto
  • Patent number: 7744802
    Abstract: An embodiment of the present invention is a technique to provide a dielectric film material with a controllable coefficient of thermal expansion (CTE). A first compound containing a first liquid crystalline component is formed. The first compound is cast into a first film. The first film is oriented in an magnetic or electromagnetic field in a first direction. The first film is cured at a first temperature.
    Type: Grant
    Filed: June 25, 2004
    Date of Patent: June 29, 2010
    Assignee: Intel Corporation
    Inventor: James C. Matayabas, Jr.
  • Publication number: 20090272269
    Abstract: Methods and apparatus for hydrodischarging and hydrocharging substrates and articles to produce enhanced ability to avoid attraction of contaminants or improved capability of removing contaminants from fluids are disclosed. In another form the method involves removal of electric charges or neutralization of charge on or within substrates. Also disclosed are methods of making using electret substrates and articles for removing particulates and mists from fluid streams.
    Type: Application
    Filed: June 3, 2009
    Publication date: November 5, 2009
    Inventor: William K. Leonard
  • Patent number: 7608215
    Abstract: There are provided steps of polarizing a ceramic composition including a perovskite compound containing Pb, Zr, Ti and Mn as main components and a heat treatment step for keeping the polarized ceramic composition within a temperature range lower than Tc (Tc denoting the Curie temperature of the ceramic composition) for 1 to 100 minutes.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: October 27, 2009
    Assignee: TDK Corporation
    Inventors: Tomohisa Azuma, Masakazu Hirose
  • Patent number: 7550903
    Abstract: In a method and device for polarizing a piezoelectric actuator according to which high-frequency pulse voltages can be used for polarizing the actuators an actuator to be polarized is mounted between two retaining elements while connected in series to a second piezoelectric actuator. The retaining elements provide the actuator (1) with a desired pretension. A compensating element compensates for changes in length of the actuator (1) so that even in the event of high-frequency pulse voltages and thus high-frequency changes in length, the pretension can be maintained within a desired range of values. Preferably, the second piezoelectric actuator has the identical design of the first actuator and is polarized with the first actuator. This enables two piezoelectric actuators to be simultaneously polarized during a polarizing process.
    Type: Grant
    Filed: January 19, 2005
    Date of Patent: June 23, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Bernhard Döllgast, Roland Niefanger, Kord Witte
  • Patent number: 7540991
    Abstract: The present invention provides an electrolyte membrane formed of an ion conductive composition. Said composition contains a liquid crystalline polymer having an ionic dissociative group. Molecular chains of the liquid crystalline polymer are orientated in a specific direction. The degree of orientation ? of the liquid crystalline polymer is in a range of 0.45 or more and less than 1, as defined by equation (1) as follows, Degree of orientation ?=(180???)/180??(1), wherein ?? is a full width at half maximum of a peak in an X-ray diffraction intensity distribution pattern obtained by measuring an intensity distribution from 0 to 360 degrees in the azimuthal angle direction, at a peak scattering angle, in an X-ray diffraction image of the electrolyte membrane. Ionic conductivity in a thickness direction of the membrane is higher than the ionic conductivity in a direction parallel to a surface of the membrane.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: June 2, 2009
    Assignee: Polymatech Co., Ltd.
    Inventors: Naoyuki Shimoyama, Fumio Saitoh, Toru Kimura, Masayuki Tobita
  • Patent number: 7452492
    Abstract: A method of fabricating a magnetic coder device, the method being of the type consisting in making a mixture of ferromagnetic particles or ferrites in a matrix, in molding the matrix, and in subjecting the molded matrix to a magnetic field so as to obtain a continuous alternation of north and south magnetic poles, which method consists in using a matrix having viscosity that is sufficiently low to enable the ferrites to migrate, in applying a magnetic field during the molding operation while maintaining the matrix at a given temperature in order to reduce its viscosity and thereby making it easier to cause the ferromagnetic particles to migrate and become oriented in their direction of easy magnetization, and to obtain discontinuous shapes having high particle concentration, and in suddenly cooling the matrix while the magnetic field is maintained so as to freeze the particles in the matrix.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: November 18, 2008
    Assignee: Hutchinson
    Inventors: Pascal Sautier, Gilles Argy
  • Publication number: 20080174736
    Abstract: Devices and methods are disclosed for realizing a high quality bulk domain grating structure utilizing mobile charges that are generated by means of photo-excitation in a substrate. An effect of light exposure (UV, visible, or a combination of wavelengths) is to generate photo-induced charges. The application of a voltage across the substrate combined with the application of light exposure causes a photo-induced current to flow through the substrate. The photo-induced charges (behaving like virtual electrode inside the material) and the photo-induced current result in both reduction of the coercive field required for domain inversion in the material and improve realization of the domain inversion pattern, which previously has not been possible at room temperature.
    Type: Application
    Filed: February 20, 2008
    Publication date: July 24, 2008
    Inventors: Lee Lisheng Huang, Simon John Field
  • Publication number: 20080014410
    Abstract: Stretched articles, such as oriented polymeric films or fibers, having microstructure features on at least one surface thereof, and processes for making such articles, are disclosed. A method of making fibers comprises forming a polymeric film having a body having a first surface and a second surface and having a longitudinal dimension. The film also comprises a plurality of elongate microstructure features disposed on the first surface of the body in a direction substantially parallel to the longitudinal dimension of the body, wherein the elongate microstructure features are substantially parallel. The method further comprises stretching the polymeric film in a direction substantially parallel to the longitudinal dimension of the body, and fibrillating the stretched polymeric film along the longitudinal dimension of the body to provide one or more fibers, wherein each fiber has at least one microstructure feature thereon.
    Type: Application
    Filed: June 28, 2006
    Publication date: January 17, 2008
    Applicant: 3M Innovative Properties Company
    Inventors: Raymond P. Johnston, Thomas I. Insley
  • Publication number: 20070235903
    Abstract: Disclosed are electret materials with outstanding thermal and charge stability. The electret materials comprise a melt blend of a thermoplastic polymer and one or more hindered hydroxylamine ester compounds that comprise at least one moiety of the formula I where Ra? is a monoacyl or diacyl radical; R1-R4 are each C1-C6alkyl; and R5 and R6 are each, independently of one another, hydrogen, C1-C6alkyl or C6-C10aryl; or R5 and R6 are together oxygen. The melt blends are subjected to an electet treatment, for example a corona treatment. The electret materials are for example nonwoven polyolefin webs and are employed as filter materials, wipes, absorbent materials, filter masks, acoustic materials, printing substrates, measuring devices or contactless switches. The present electret materials may also comprise a further additive selected from the group consisting of the hindered amine light stabilizers, the hydroxyphenylalkylphosphonic esters or monoesters and the aromatic trisamide nucleating agents.
    Type: Application
    Filed: April 3, 2007
    Publication date: October 11, 2007
    Inventors: Hui Chin, Matthew E. Gande, Andrew J. Leggio
  • Patent number: 7015254
    Abstract: The present invention includes an apparatus for generating an inorganic polymer electret in a colloidal state, the inorganic electret in a colloidal state itself, and applications for the inorganic electret in a colloidal state. The invention includes a method for generation of a colloidal silica particle which is dipolar in that it is positively charged in the nucleus and negatively charged on the outer surface leaving a net negative charge to the particle. The apparatus includes the ability to control particle size, uniformity, consistency, hydration, and three dimensional structure which is desirable for various applications.
    Type: Grant
    Filed: December 26, 2000
    Date of Patent: March 21, 2006
    Inventor: Robert R. Holcomb
  • Patent number: 6783574
    Abstract: Electret filter media comprising a nonwoven web of thermoplastic nonconductive microfibers having trapped charge, said charge provided by (1) subjecting the nonwoven web to a corona treatment, followed by (2) impingement of jets of water or a stream of water droplets on the web at a pressure sufficient to provide the web with filtration enhancing electret charge and (3) drying the web. This electret filter media may be used in a respiratory mask to provide extraordinarily good filtration properties.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: August 31, 2004
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Seyed A. Angadjivand, Marvin E. Jones, Daniel E. Meyer
  • Publication number: 20040139911
    Abstract: A perovskite compound of the formula, (Na1/2Bi1/2)1-xMx(Ti1-yM′y)O3±z, where M is one or more of Ca, Sr, Ba, Pb, Y, La, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb and Lu; and M′ is one or more of Zr, Hf, Sn, Ge, Mg, Zn, Al, Sc, Ga, Nb, Mo, Sb, Ta, W, Cr, Mn, Fe, Co and Ni, and 0.01<x<0.3, and 0.01<y<0.3, and z<0.1 functions as an electromechanically active material. The material may possess electrostrictive or piezoelectric characteristics.
    Type: Application
    Filed: August 5, 2003
    Publication date: July 22, 2004
    Inventors: Yet-Ming Chiang, Sossity A. Sheets, Gregory W. Farrey, Nesbitt W. Hagood, Andrey Soukhojak, Haifeng Wang
  • Patent number: 6759792
    Abstract: In a polarization method of the multi-layered piezoelectric body in which a plurality of piezoelectric layers and a plurality of internal electrodes are alternately laminated and adjacent piezoelectric layers are polarized in the thickness direction such that the polarized directions thereof are in opposite directions, a first polarization process in which an electric field in one direction is applied in the thickness direction to the multi-layered piezoelectric body and a polarization is uniformly performed in the thickness direction, and a secondary polarization process in which an electric field in the opposite direction is applied to the piezoelectric layers on both sides of one of the internal electrodes and the direction of polarization of only one of the piezoelectric layers on one side of the internal electrode is reversed are provided.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: July 6, 2004
    Assignee: Murata Manufacturing Co., LTD
    Inventor: Mikio Nakajima
  • Patent number: 6750592
    Abstract: The present invention relates to a surface acoustic wave filter in which a plurality of pairs of comb electrode patterns are formed on an upper surface of a chip substrate made of a piezoelectric material. The surface acoustic wave filter includes a high-resistance pattern formed to surround a peripheral portion of the chip substrate on an upper surface side thereof, and a plurality of patterns formed to connect the high-resistance pattern to the respective comb electrode patterns.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: June 15, 2004
    Assignee: NRS Technologies, Inc.
    Inventors: Yoshihiro Takahashi, Tadaaki Tsuda, Yasushi Yamamoto, Hiroshi Kawahara
  • Patent number: 6642341
    Abstract: Molded polyurethane articles having improved flex modulus and impact strength are produced by subjecting a polyurethane-forming reaction mixture which has been introduced into a mold to a static electric field. The static electric field must have a field strength which is less than the dielectric strength of the polyurethane being produced but sufficiently strong to align the hard segment dipoles of the polyurethane.
    Type: Grant
    Filed: May 21, 2002
    Date of Patent: November 4, 2003
    Assignee: Bayer Corporation
    Inventors: Kieth G. Spitler, Allison E. Yeske
  • Patent number: 6628042
    Abstract: In order to polarize a piezoelectric material in high-temperature gas, a temperature-raising portion raises the temperature of the piezoelectric material to a temperature required to polarize the piezoelectric material. A constant-temperature bath has an atmosphere of the temperature of which is kept at the required temperature, and incorporates a polarizing portion that polarizes the piezoelectric material whose temperature is kept at the required temperature. When the temperature of the piezoelectric material is raised quickly to the temperature required to polarize the piezoelectric material by the temperature raising portion and is placed into the constant-temperature bath, the temperature of the piezoelectric material is at a temperature near a set temperature of the inside of the constant-temperature bath, so that the piezoelectric material can be polarized in a short period of time with high precision.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: September 30, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Hiroshi Tomohiro
  • Patent number: 6602311
    Abstract: A fiber spinning device and process for manufacturing a web of fibers including a homogeneous mixture of fibers of different characteristics. Monocomponent fibers of different polymers can be extruded side-by-side from the same die system. Sheath/core bicomponent fibers can be alternated with monocomponent fibers formed of the same core polymer as used in the bicomponent fibers. Bicomponent fibers having a common core polymer and different sheath polymers can be extruded from alternate spinneret orifices in the same die plate. Multiple distribution plates are provided with surface grooves or depressions to direct polymer materials from independent sources to only selected spinneret openings in an array of spinneret openings while maintaining the polymers segregated from each other.
    Type: Grant
    Filed: February 25, 2002
    Date of Patent: August 5, 2003
    Inventor: Richard M. Berger
  • Patent number: 6593681
    Abstract: A polarization apparatus is provided wherein a piezoelectric body tube 3 is wound around a first rotation drum 5 and a second rotation drum 6 and a coaxial flexible piezoelectric body 2 is polarized while the piezoelectric body tube 3 is wound. According to the polarization apparatus, polarization can be conducted except for the coaxial flexible piezoelectric body 2 of the portion containing a defect and a defect existing in the piezoelectric body tube 3 of a given length can also be detected before an outer electrode 4 is formed.
    Type: Grant
    Filed: December 12, 2001
    Date of Patent: July 15, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsuo Ebisawa, Takeshi Nagai, Narutoshi Kanazawa, Masahiko Ito, Yuko Fujii, Tooru Sugimori
  • Publication number: 20030038275
    Abstract: A device includes a polycrystalline body having a stoichiometry that is described by [Pb(Mg1/3Nb2/3)O3](1-x)[PbTiO3]x. The value of x is in a range of about 0.31 to about 0.47.
    Type: Application
    Filed: October 9, 2002
    Publication date: February 27, 2003
    Inventors: Sang-Wook Cheong, Tae-Yeong Koo
  • Patent number: 6521166
    Abstract: A DC voltage is applied to a piezoelectric body for polarization treatment in the air and in an atmosphere with a temperature equal to or higher than an aging temperature, and then, the piezoelectric body is aged at the aging temperature. The polarization degree is determined based on the frequency characteristic while the piezoelectric body is polarized. The application of the DC voltage is stopped at the time when the measured polarization degree reaches a set level. The set level is determined based on a correlation between the polarization degree obtained immediately before the application of the DC voltage is stopped and the stable polarization degree obtained after the aging and the ordinary temperature restoration following the stop of the voltage application.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: February 18, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroshi Tomohiro, Naoki Fujii
  • Patent number: 6464925
    Abstract: A method of polarization-treating a piezoelectric body, which is constructed such that current flows through the piezoelectric body in response to application of a DC voltage to the piezoelectric body, includes the steps of measuring current flowing through the piezoelectric body, and stopping the application of the DC voltage at the time when the measured current value reaches a set level. The polarization degree is controlled based on the current value by utilization of a correlation between the current and the polarization degree during polarization. With this method, a desired polarization degree is obtained, and dispersion of the polarization is reduced.
    Type: Grant
    Filed: August 12, 2000
    Date of Patent: October 15, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroshi Tomohiro, Naoki Fujii
  • Patent number: 6414089
    Abstract: A method of manufacturing a polymer film having second order non-linear optical properties which has excellent stability of orientated molecules and does not become disorientated, and a polymer film and a non-linear optical element are provided. A polymer solution is placed between two substrates, which are disposed substantially perpendicular with respect to a rotating stand and substantially symmetrical with respect to a rotation axis of the rotating stand, and the rotating stand is rotated. A polymer film having second order non-linear optical properties is formed by the centrifugal force generated at the polymer solution.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: July 2, 2002
    Assignees: Riken, Japan Science and Technology Corporation
    Inventors: Hiromi Kimura-Suda, Hiroyuki Sasabe, Tatsuo Wada
  • Patent number: 6406657
    Abstract: A method for imparting an electrostatic charge to a nonwoven fibrous web 20. The fibrous web 20 is wetted with a wetting liquid 24, followed by being saturated with an aqueous polar liquid 30 and drying 31. The resulting dried product is an electret article 43 that could be used as an air filter in, for example, a respirator 50.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: June 18, 2002
    Assignee: 3M Innovative Properties Company
    Inventors: Philip D. Eitzman, Alan D. Rousseau
  • Patent number: 6403012
    Abstract: In a method of polarization-treating a piezoelectric material, the maximum polarization degree &Dgr;f180max achieved by 180° rotation is determined. A residual polarization degree &Dgr;f as a target value and the maximum polarization degree &Dgr;f180max are compared. In the case of &Dgr;f≦&Dgr;f180max, a determination is made as to the temperature TA for obtaining the polarization degree &Dgr;f made up solely of the polarization degree achieved by 180° rotation. Half-polarization is carried out at the temperature TA, and aging is conducted at the temperature TA, whereby a piezoelectric material of which the ratio of the polarization achieved by 180° rotation is 100%, which is stable thermally with passage of time, and has a polarization degree &Dgr;f correctly coincident with a target value, can be obtained.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: June 11, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroshi Tomohiro, Naoki Fujii
  • Patent number: 6398847
    Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.
    Type: Grant
    Filed: January 6, 2000
    Date of Patent: June 4, 2002
    Assignee: 3M Innovative Properties Company
    Inventors: Marvin E. Jones, Christopher S. Lyons, David B. Redmond, Jeffrey L. Solomon, Seyed Abolhassan Angadjivand
  • Patent number: 6387295
    Abstract: An alkali metal-containing niobate-based piezoelectric material composition comprises a solid solution represented by a composition formula (ANbO3) (A: alkali metal), and at least one additive selected from Cu, Li and Ta.
    Type: Grant
    Filed: February 23, 2000
    Date of Patent: May 14, 2002
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventor: Yasuyoshi Saito
  • Patent number: 6365088
    Abstract: The process of forming an electret nonwoven web, the process including the steps of providing a nonwoven web, generating a DC corona discharge from an apparatus including an anode electrically configured as a parallel device, and subjecting the web to DC corona discharge to form an electret.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: April 2, 2002
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventors: Preston Biggers Knight, David Lewis Myers, John Joseph Lassig, David Grant Midkiff, Rick Leon Busby, Anthony Lee Lamanac, Leonid Anthony Turkevich
  • Patent number: 6168746
    Abstract: A method for injection molding fine particulate ceramic ferroelectric materials to form an article such as ink jet printhead includes the steps of spray drying fine particulate ceramic ferroelectric material to form agglomerate material; mixing the spray dried fine particulate ceramic ferroelectric agglomerate material with a binder system including materials selected from the group consisting of wax having wax components of different molecular weight, magnesium-X silicate, agaroid gel forming material, and agaroid gel forming material mixed with magnesium-X silicate to form a compounded material; injecting the compounded material at a selected pressure into a mold to form a green article; debinding or drying the green article; sintering the debinded or dried green article to form the final molded article; poling the final molded article to align the electrical dipoles within the piezoelectric material; forming a coating of conductive material over the top and bottom surfaces of the final molded article and t
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: January 2, 2001
    Assignee: Eastman Kodak Company
    Inventors: Dilip K. Chatterjee, Syamal K. Ghosh, James K. Lee
  • Patent number: 6156255
    Abstract: A method of patterning domains within a body of a ferroelectric material includes the application of an electric field thereto via spaced conductors. Prior to applying the electric field to the material effects on the patterning of the existence of fringe electric field components which will be created in said body by said application of an electric field, surface treatments, and relative geometries of the body and the conductors are examined.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: December 5, 2000
    Assignee: The Board of Trustees of the Leland Stanford, Jr. University
    Inventors: Robert L. Byer, Martin M. Fejer, Gregory D. Miller, Lawrence E. Myers
  • Patent number: 6054071
    Abstract: Twisting balls (10) for an electric-paper display are formed from a polarizable material and encapsulated in a protective shell (12). The balls (10) are disposed between first and second electrodes (14, 16) which generate an electric field. The electric field polarizes each ball (10) transforming each into a dipole electret having a first and second charged poles. At least one colorant (20) is applied to each of the balls (10) to obtain multichromal balls such that the charged poles are distinct from each other. The polarized multichromal balls may then be used in fabricating an electric-paper display by encapsulating the balls (10) in an array such that each ball is capable of rotating in response to a selectively applied electric field.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: April 25, 2000
    Assignee: Xerox Corporation
    Inventor: James C. Mikkelsen, Jr.
  • Patent number: 6013221
    Abstract: A method of domain patterning a body of ferroelectric material is disclosed. This method includes patterning the surface of the material with conducting strips for applying an electric field of desired configuration to said body and covering the conductive strips and surface of the body with insulating material to control the fringe electric field components in the body of ferromagnetic material.
    Type: Grant
    Filed: May 13, 1998
    Date of Patent: January 11, 2000
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Robert L. Byer, Martin M. Fejer, Gregory D. Miller, Lawrence E. Myers
  • Patent number: 6001299
    Abstract: A process for electret treatment is described, involving(1) placing the dielectric article between a combination of a first ion-repulsive electrode and a first ion-attractive electrode and between a combination of a second ion-repulsive electrode and a second ion-attractive electrode, under a specified arrangement;(2) supplying a first positive ion and a first negative ion from a first ion generating means between the dielectric article and the first ion-repulsive electrode, the first ion generating means being selected from an alternating current surface discharge element and an alternating current corona-type ion generating element;(3) applying a direct current voltage between the first ion-repulsive electrode and the first ion-attractive electrode to produce a first potential difference therebetween, whereby only one of the first positive and negative ions is moved in a specified direction, and is transferred on the dielectric article;(4) supplying a second positive ion and a second negative ion from a sec
    Type: Grant
    Filed: August 13, 1997
    Date of Patent: December 14, 1999
    Assignee: Japan Vilene Company, Ltd.
    Inventors: Masaaki Kawabe, Daisuke Ito
  • Patent number: 5964926
    Abstract: Disclosed is an improved filter formed from a non-dielectric material which has been coated with a dielectric material and electret treated by, for example, DC corona discharge treatment. Also disclosed is a method for the formation of the filter.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: October 12, 1999
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventor: Bernard Cohen
  • Patent number: 5886070
    Abstract: The present invention offers a production method for anisotropic resin-bonded magnets with precise dimensions in high productivity. It comprises the aligning step in which the preform is preliminary compression-molded in the preforming molding die 22 in the preforming press 20 with an applied magnetic field to align the magnetization direction of the magnet powder at a temperature in which the thermosetting resin in the compound becomes liquid state, the transferring step in which said preform is transferred from preforming press 20 to densifying molding die 32 in a densifying press 30, and densifying step in which said partly cured preform is compression-molded by applying pressure in a densifying press 30 to obtain desired shape of magnet.
    Type: Grant
    Filed: July 1, 1997
    Date of Patent: March 23, 1999
    Assignee: Aichi Steel Works, Ltd.
    Inventors: Yoshinobu Honkura, Hironari Mitarai, Koichi Maekawa, Yoshinobu Sugiura
  • Patent number: 5800767
    Abstract: A method of domain patterning a body of ferroelectric material. The method includes the steps of adhering spaced conducting strips to a surface of said body; covering portions of said surface of said body between said strips with material which is insulative relative to electric current produced when an electric field configuration is created in said body and which controls the formation of fringe electric field components in said material; and applying potentials simultaneously to said conducting strips and to a surface of said insulative material to create an electric field configuration in said body whereby said strips define said electric field configuration within said body and wherein said insulating material between said strips defines a potential within said body which is generally the same as the potential applied to said conducting strips.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: September 1, 1998
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Robert L. Byer, Martin M. Fejer, Gregory D. Miller, Lawrence E. Myers
  • Patent number: 5725825
    Abstract: A method of producing a cylindrical piezoelectric element includes:(a) injecting the molding fluid containing calcined powder of piezoelectric material in a mold having cylindrical cavity and wire-shaped core inserted therein;(b) heating to dry the molding fluid injected in the mold so as to obtain cylindrical member;(d) removing cylindrical member from the mold; and(e) sintering the cylindrical member to obtain a piezoelectric element.
    Type: Grant
    Filed: July 9, 1996
    Date of Patent: March 10, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Hideo Hotomi, Kenji Masaki, Kusunoki Higashino