Patents by Inventor Chak M. Leung
Chak M. Leung has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8840560Abstract: A hand-operated intracardiac echocardiography (ICE) catheter is described for flexed and rotational steering is described for improved catheter operation, control and less trauma on patients. The disclosed catheter assembly includes ultrasound transducers mounted upon a rotatable tip mounted on a distal end of a flexible elongate shaft. A set of steering lines are controlled by a steering actuator to articulate bidirectionally a distal segment of the catheter. Another steering actuator controls rotation of a torque member that, in turn is coupled to the rotatable tip. A user, through the steering actuators, affects repositioning the ultrasonic transducers by repositioning exposed control surfaces of the steering actuators lengthwise along the housing of the handle.Type: GrantFiled: April 4, 2007Date of Patent: September 23, 2014Assignee: Volcano CorporationInventors: Norman Hugh Hossack, Richard Scott Huennekens, Rovil Rae Pascual Arcia, Ernest W. Heflin, Stephen C. Davies, Richard Klosinski, Blair D. Walker, Chak M. Leung
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Patent number: 6002552Abstract: A head gimbal assembly includes an adaptive loading/unloading suspension with an aerodynamic compensation mechanism formed with or attached to the load beam. The compensation mechanism causes a variable and programmable dynamic gram load to be applied on the suspension such that a low gram load is achieved at the time of dynamic head loading, thus significantly minimizing or totally eliminating head-to-disk contact. The variable suspension gram load feature can be combined with an air slider bearing design to achieve optimal flying height performance and cost effectiveness. Such combination provides the air bearing design with an additional degree of freedom to achieve a more uniform flying height and improved altitude sensitivity than under a constant preload.Type: GrantFiled: January 19, 1999Date of Patent: December 14, 1999Assignee: Read-Rite CorporationInventor: Chak M. Leung
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Patent number: 5959806Abstract: A head gimbal assembly includes an adaptive loading/unloading suspension with an aerodynamic compensation mechanism formed with or attached to the load beam. The compensation mechanism causes a variable and programmable dynamic gram load to be applied on the suspension such that a low gram load is achieved at the time of dynamic head loading, thus significantly minimizing or totally eliminating head-to-disk contact. The variable suspension gram load feature can be combined with an air slider bearing design to achieve optimal flying height performance and cost effectiveness. Such combination provides the air bearing design with an additional degree of freedom to achieve a more uniform flying height and improved altitude sensitivity than under a constant preload.Type: GrantFiled: June 12, 1997Date of Patent: September 28, 1999Assignee: Read-Rite CorporationInventor: Chak M. Leung
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Patent number: 5727308Abstract: A magnetic head is formed by depositing a pad pattern on a substrate with a flat upper surface. The pad pattern includes two spaced inner slopes that face each other. An air bearing surface plane is defined between the inner slopes where the air bearing surface of the magnetic head is to be formed. An undercoat layer is deposited on the pad pattern, such that the undercoat layer follows the contour of the inner slopes to form a recessed region between the inner slopes. A magnetic layer is deposited on the undercoat layer to form a first pole P1 that follows the contours of the inner slopes. A gap layer is then formed on top of the first pole P1 and follows its contour. Conductive coils are formed within the recessed region. A second magnetic layer is deposited over the coils and gap layer to form a second pole P2. The magnetic head is lapped at the air bearing surface plane to form the final air bearing surface.Type: GrantFiled: July 25, 1996Date of Patent: March 17, 1998Assignee: Read-Rite CorporationInventors: Chak M. Leung, Charles R. Bond, Daniel A. Nepela
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Patent number: 5535074Abstract: The headstack of a disk drive is formed with separate sections, each of which supports a plurality of head suspensions. In one embodiment, the sections are blocks on which pairs of head suspensions having UP and DOWN facing sliders are mounted. The blocks are individually positioned and aligned relative to a disk stack. In a second embodiment, head suspensions are supported by a pair of modules. A first module supports suspensions with UP head sliders and a second module supports suspensions with DOWN head sliders. The modules interlock so that an alternating arrangement of UP and DOWN heads result. By use of a comb-like head loading tool, the suspensions that carry the head sliders are spaced and loaded to respective disk surfaces.Type: GrantFiled: January 9, 1995Date of Patent: July 9, 1996Assignee: Read-Rite CorporationInventor: Chak M. Leung
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Patent number: 5473485Abstract: A tripad air bearing slider useful in a disk drive is designed with two outer pads that extend from two or more tapered sections at the leading edge of the slider towards the trailing edge. The pads are configured and angled so that a desired lift force is obtained that acts in opposition to a force provided by a spring loaded flexure or load beam. The angles that define the shape of the three pads are formed by simple mechanical cutting, using a diamond cutting wheel, for example, or alternatively by ion milling or reactive ion etching.Type: GrantFiled: February 6, 1995Date of Patent: December 5, 1995Assignee: Read-Rite CorporationInventors: Chak M. Leung, Carroll S. Gooden, Edgar M. Williams
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Patent number: 5359480Abstract: An air bearing slider of a thin film magnetic head assembly is configured with tapered portions at its leading edge and with two side rails extending from the tapers to the trailing edge of the slider. Recesses that are formed in the rails are spaced from the tapered portions. Each rail may be configured with one or more recesses. In one embodiment, the two recesses of each rail are asymmetrically disposed relative to the tapered portion of the rail and to the trailing edge of the slider. In such embodiment, the recesses do not extend to the slider trailing edge. In alternative embodiments, the recesses are spaced from the tapered portions but extend to the trailing edge of the slider. The recesses may be arcuately shaped or have angled portions or other geometries.Type: GrantFiled: December 21, 1992Date of Patent: October 25, 1994Assignee: Read-Rite CorporationInventors: Daniel A. Nepela, Chak M. Leung, Ciuter Chang
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Patent number: 5327310Abstract: A thin film magnetic head assembly useful for contact recording in a disk drive comprises an air bearing slider formed with only a single air bearing rail. The slider is substantially L-shaped having a leg portion on which a pedestal with an air bearing surface is provided. A wear pad is formed on the pedestal and encompasses the pole tips and transducing gap of the transducer. The wear pad makes contact with the magnetic disk during operation of the disk drive. The small area of the wear pad makes minimal contact with the surface of the magnetic disk so that frictional effects are significantly reduced thereby extending the wear life of the magnetic head. An alternative embodiment of a contact head slider uses a tripad design wherein the front pads fly relative to the disk and the rear pad which supports the transducer is in contact with the rotating disk during operation of a disk drive.Type: GrantFiled: June 25, 1992Date of Patent: July 5, 1994Assignee: Read-Rite CorporationInventors: Peter G. Bischoff, Chak M. Leung, Stephen S. Murray
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Patent number: 5312644Abstract: A thin-film magnetoresistive playback head having films providing magnetic shielding and magnetic bias. At least one of the magnetic shield layers is also conductive so that the functions of shielding and biasing are combined. Preferably, both shield layers are conductive. A multiple element channel head is disclosed in which the magnetic/conductive layers extend in series from one transducer section to the next, allowing a single bias current to bias all of the sections.Type: GrantFiled: September 17, 1993Date of Patent: May 17, 1994Assignee: Minnesota Mining and Manufacturing CompanyInventors: Theodore A. Schwarz, Peter G. Bischoff, Chak M. Leung, Johnny C. Chen, Pradeep Thayamballi
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Patent number: 5311385Abstract: A thin-film magnetoresistive playback head having films providing magnetic shielding and magnetic bias. At least one of the magnetic shield layers is also conductive so that the functions of shielding and biasing are combined. Preferably, both shield layers are conductive. A multiple element channel head is disclosed in which the magnetic/conductive layers extend in series from one transducer section to the next, allowing a single bias current to bias all of the sections.Type: GrantFiled: December 18, 1991Date of Patent: May 10, 1994Assignee: Minnesota Mining and Manufacturing CompanyInventors: Theodore A. Schwarz, Peter G. Bischoff, Chak M. Leung, Johnny C. Chen, Pradeep Thayamballi
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Patent number: 5299081Abstract: A magnetic head suspension assembly is fabricated with a load beam formed with a central triangular-type major section, a tongue section at the front end and a rigid mount section at the opposing rear end. The load beam has flanges along the sides of the central major section and the rear mount section. A leaf spring is provided between the central major section and the rear mount section for providing flexibility to the suspension. A flexure that is joined to the load beam is formed with a U-shaped finger surrounded by a cutout at the front end of the flexure. A load dimple that is provided on the flexure is in contact with the load beam. The flexure supports an air bearing slider that pitches and rolls relative to a disk surface. The flexure does not extend beyond the load dimple of the flexure or the front leading edge of the slider. The suspension is characterized by a high first bending mode frequency and low pitch and roll stiffness.Type: GrantFiled: August 5, 1992Date of Patent: March 29, 1994Assignee: Read-Rite CorporationInventors: Michael R. Hatch, Chak M. Leung, Stephen S. Murray
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Patent number: 5282103Abstract: A magnetic head suspension assembly is fabricated with an integral piece which includes a load beam section, a flexure section, a rear mount section and a leaf spring section between the load beam and rear mount. A tongue extends from the load beam to the flexure and has a down-facing load dimple which contacts the non-air bearing surface of an attached air bearing slider. The flexure includes narrow thin legs adjacent to a cutout that delineates the load beam tongue. The head suspension is characterized by a high first bending mode frequency and low pitch and roll stiffness.Type: GrantFiled: April 5, 1993Date of Patent: January 25, 1994Assignee: Read-Rite CorporationInventors: Michael R. Hatch, Chak M. Leung
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Patent number: 5237476Abstract: A thin film tape head assembly is formed by depositing a multiplicity of thin film transducers on a ceramic wafer or substrate. The wafer is divided into head bars, each of which has one or more thin film transducers on its face. End sections and a cover bar are joined to the head bar to form a head bar subassembly. A flexible cable or electrical pins are provided between the end sections to enable electrical connection between the head circuit and external circuitry. By joining a number of head bar subassemblies, a multigap thin film tape head assembly is produced to serve as a read/write device.Type: GrantFiled: May 28, 1991Date of Patent: August 17, 1993Assignee: Read-Rite Corp.Inventors: Peter G. Bischoff, Carroll S. Gooden, Chak M. Leung
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Patent number: RE39478Abstract: A magnetic head suspension assembly is fabricated with an integral piece which includes a load beam section, a flexure section, a rest mount section and a leaf spring section between the load beam and rear mount. A tongue extends from the load beam to the flexure and has a down-facing load dimple which contacts the non-air bearing surface of an attached air bearing slider. The flexure includes narrow thin legs adjacent to a cutout that delineates the load beam tongue. The head suspension is characterised by a high first bending mode frequency and low pitch and roll stiffness.Type: GrantFiled: June 13, 1996Date of Patent: January 23, 2007Assignee: Western Digital (Fremont), Inc.Inventors: Michael R. Hatch, Chak M. Leung
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Patent number: RE40203Abstract: A magnetic head suspension assembly is fabricated with an integral piece which includes a load beam section, a flexure section, a rear mount section and a leaf spring section between the load beam and rear mount. A tongue extends from the load beam to the flexure and has a down-facing load dimple which contacts the non-air bearing surface of an attached air bearing slider. The flexure includes narrow thin legs adjacent to a cutout that delineates the load beam tongue. The head suspension is characterized by a high first bending mode frequency and low pitch and roll stiffness.Type: GrantFiled: June 13, 1996Date of Patent: April 1, 2008Assignee: Western Digital (Fremont), LLCInventors: Michael R. Hatch, Chak M. Leung
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Patent number: RE41401Abstract: A magnetic head suspension assembly is fabricated with an integral piece which includes a load beam section, a flexure section, a rear mount section and a leaf spring section between the load beam and rear mount. A tongue extends from the load beam to the flexure and has a down-facing load dimple which contacts the non-air bearing surface of an attached air bearing slider. The flexure includes narrow thin legs adjacent to a cutout that delineates the load beam tongue. The head suspension is characterized by a high first bending mode frequency and low pitch and roll stiffness.Type: GrantFiled: July 30, 2003Date of Patent: June 29, 2010Assignee: Western Digital (Fremont), LLCInventors: Michael R. Hatch, Chak M. Leung