Patents by Inventor Sanjoy Ghose

Sanjoy Ghose 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).

  • Publication number: 20120307500
    Abstract: A lighting system is described. The lighting system includes a lamp and a first container including a first phase change material thermally connected to the lamp. Heat generated by the lamp during operation is conducted to the first phase change material. The system also includes a second container including a second phase change material thermally connected to the lamp. Heat generated by the lamp during operation is also conducted to the second phase change material, and the second phase change material has a transition point temperature lower than the transition point temperature of the first phase change material of the first container to account for a temperature drop between the second container and the first container. The lighting system also includes a temperature sensor for reducing lamp power if the lamp becomes too hot, and a mounting bracket which may also conduct heat away from the lamp.
    Type: Application
    Filed: February 23, 2012
    Publication date: December 6, 2012
    Applicant: Lumenetix, Inc.
    Inventors: Robert Hitchcock, James Kingman, Matthew D. Weaver, Dustin Cochran, Sanjoy Ghose
  • Patent number: 8123389
    Abstract: A lighting system is described. The lighting system includes a lamp and a first container including a first phase change material thermally connected to the lamp. Heat generated by the lamp during operation is conducted to the first phase change material. The system also includes a second container including a second phase change material thermally connected to the lamp. Heat generated by the lamp during operation is also conducted to the second phase change material, and the second phase change material has a transition point temperature lower than the transition point temperature of the first phase change material of the first container to account for a temperature drop between the second container and the first container. The lighting system also includes a temperature sensor for reducing lamp power if the lamp becomes too hot, and a mounting bracket which may also conduct heat away from the lamp.
    Type: Grant
    Filed: April 9, 2010
    Date of Patent: February 28, 2012
    Assignee: Lumenetix, Inc.
    Inventors: Robert Hitchcock, James Kingman, Matthew Weaver, Dustin Cochran, Sanjoy Ghose
  • Publication number: 20110303946
    Abstract: A phase change material (PCM) is used as thermal storage for lighting systems. The PCM is placed in a thermally conductive container in close contact with the lighting system. As the PCM absorbs heat, it changes from a solid to a liquid state, but the temperature of the PCM is clamped at its melting point temperature. For LED-based systems, the PCM is selected to have a melting point such that the junction temperatures of the LEDs in the system are maintained at approximately their optimum operating temperature inside the lighting system housing. Because the thermal conductivity of the molten PCM is poor, a low thermal resistance heat flow path is provided from the PCM to the container.
    Type: Application
    Filed: June 28, 2011
    Publication date: December 15, 2011
    Inventors: Matthew Weaver, James Kingman, Sanjoy Ghose
  • Patent number: 7969075
    Abstract: A phase change material (PCM) is used as thermal storage for lighting systems. The PCM is placed in a thermally conductive container in close contact with the lighting system. As the PCM absorbs heat, it changes from a solid to a liquid state, but the temperature of the PCM is clamped at its melting point temperature. For LED-based systems, the PCM is selected to have a melting point such that the junction temperatures of the LEDs in the system are maintained at approximately their optimum operating temperature inside the lighting system housing. Because the thermal conductivity of the molten PCM is poor, a low thermal resistance heat flow path is provided from the PCM to the container.
    Type: Grant
    Filed: February 10, 2009
    Date of Patent: June 28, 2011
    Assignee: Lumenetix, Inc.
    Inventors: Matthew Weaver, James Kingman, Sanjoy Ghose
  • Publication number: 20110134645
    Abstract: A lighting system is described. The lighting system includes a lamp and a first container including a first phase change material thermally connected to the lamp. Heat generated by the lamp during operation is conducted to the first phase change material. The system also includes a second container including a second phase change material thermally connected to the lamp. Heat generated by the lamp during operation is also conducted to the second phase change material, and the second phase change material has a transition point temperature lower than the transition point temperature of the first phase change material of the first container to account for a temperature drop between the second container and the first container. The lighting system also includes a temperature sensor for reducing lamp power if the lamp becomes too hot, and a mounting bracket which may also conduct heat away from the lamp.
    Type: Application
    Filed: April 9, 2010
    Publication date: June 9, 2011
    Inventors: Robert Hitchcock, James Kingman, Matthew Weaver, Dustin Cochran, Sanjoy Ghose
  • Publication number: 20100201241
    Abstract: A phase change material (PCM) is used as thermal storage for lighting systems. The PCM is placed in a thermally conductive container in close contact with the lighting system. As the PCM absorbs heat, it changes from a solid to a liquid state, but the temperature of the PCM is clamped at its melting point temperature. For LED-based systems, the PCM is selected to have a melting point such that the junction temperatures of the LEDs in the system are maintained at approximately their optimum operating temperature inside the lighting system housing. Because the thermal conductivity of the molten PCM is poor, a low thermal resistance heat flow path is provided from the PCM to the container.
    Type: Application
    Filed: February 10, 2009
    Publication date: August 12, 2010
    Inventors: Matthew Weaver, James Kingman, Sanjoy Ghose
  • Patent number: 6574174
    Abstract: An optical information storage system using optical storage media including multiple data layers or stacks wherein each of the multiple data stacks has a storage density comparable to a conventional single layer optical disk. The optical data storage system comprises an optical medium having a single dedicated servo layer and multiple data stacks which each contain an embedded servo format, a servo laser beam positioned to maintain a first focus point on the dedicated servo reference layer, a read-write laser beam positioned to maintain a second focus point on one of the data stacks, a first, dedicated servo system which provides focus and tracking error correction according to error signals generated from the dedicated servo layer, and a second, embedded servo system which provides focus and tracking error correction according to error signals generated from the data stacks.
    Type: Grant
    Filed: April 15, 2000
    Date of Patent: June 3, 2003
    Assignee: Siros Technologies, Inc.
    Inventors: James R. Amble, Lambrerrtus Hesselink, Tokyuki Honda, Mark E. McDonald, Michael V. Morelli, Andrew J. Daiber, Herman A. Ferrier, Sanjoy Ghose, Thomas A. Kridl, Matthew Lipson, Shunichi Nishimura, Sergei Sochava, LeRoy A. Volz
  • Patent number: 6540397
    Abstract: An optical information medium comprising at least two data layers for bearing recorded information, and a servo layer for bearing tracking servo, information which is independently formed from the data layers; wherein the medium is used with a recording or reading system wherein a data beam for recording or reading the data in the data layer and a servo beam for reading the tracking servo information in the servo layer are used, and the servo layer is read by the servo beam that had passed through the data layer; and a filter layer is disposed between the data layer and the servo layer, and the filter layer exhibits higher absorption to the data beam than to the servo beam.
    Type: Grant
    Filed: April 5, 2001
    Date of Patent: April 1, 2003
    Assignees: Siro Technologies, Inc., TDK Corporation
    Inventors: Jiro Yoshinari, Takuya Tsukagoshi, Hideki Hirata, Naoki Hayashida, Tokuyuki Honda, Mark E. McDonald, Michael V. Morelli, Andrew J. Daiber, Sanjoy Ghose, Lambertus Hesselink, Shunichi Nishimura, Sergei Sochava
  • Publication number: 20020041564
    Abstract: An optical information medium comprising at least two data layers for bearing recorded information, and a servo layer for bearing tracking servo information which is independently formed from the data layers; wherein the medium is used with a recording or reading system wherein a data beam for recording or reading the data in the data layer and a servo beam for reading the tracking servo information in the servo layer are used, and the servo layer is read by the servo beam that had passed through the data layer; and a filter layer is disposed between the data layer and the servo layer, and the filter layer exhibits higher absorption to the data beam than to the servo beam.
    Type: Application
    Filed: April 5, 2001
    Publication date: April 11, 2002
    Inventors: Jiro Yoshinari, Takuya Tsukagoshi, Hideki Hirata, Naoki Hayashida, Tokuyuki Honda, Mark E. McDonald, Michael V. Morelli, Andrew J. Daiber, Sanjoy Ghose, Lambertus Hesselink, Shunichi Nishimura, Sergel Sochava
  • Patent number: 6069766
    Abstract: A disc drive system having at least one hard disc of approximately 48 mm diameter having concentric tracks is supported by a hub positioned in a centrally located aperture of approximately 12 mm diameter. The disc is rotated at a constant speed by a brushless DC motor attached to the hub. A transducer means for communicating information with the hard disc is moved relative to the disc surface by a positioning means. The positioning means includes a voice coil motor for selectably and accurately positioning the transducer means over the tracks on the hard disc. The disc drive system is enclosed in a housing means constructed from ferrous material having a base portion and a shell portion. The positioning means has a shaft about which the positioning means rotates. To provide a small, rugged assembly, the shaft is mounted at each end between the shell portion and base portion of the housing. Additionally, the shaft of the brushless DC motor is mounted in the same manner.
    Type: Grant
    Filed: November 5, 1997
    Date of Patent: May 30, 2000
    Assignee: Seagate Technology, Inc.
    Inventors: Ramgopal Battu, Iraj Jabbari, Sanjoy Ghose
  • Patent number: 5872688
    Abstract: The invention is a miniature disc drive system. In the preferred embodiment of the invention, a positioner for positioning a transducer includes an actuator arm having the transducer mounted at one end and a voice coil motor (VCM) mounted at the other end. A pivot is centrally located along the actuator arm, whereby the VCM, when activated, can rotate the transducer over a disc or discs having approximately 45 mm diameters. The VCM is preferably a moving voice coil-type having a voice coil attached to the actuator arm and two magnets positioned above and below the voice coil such that the voice coil can freely move between them. One magnet is mounted to a base portion of a housing which encloses the entire disc drive system. The other magnet is mounted to roof portion of the housing. Thus, the housing is integrated into the active components of the disc drive and permits a significant size reduction to be achieved.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: February 16, 1999
    Assignee: Seagate Technology, Inc.
    Inventors: Ramgopal Battu, Iraj Jabari, Sanjoy Ghose
  • Patent number: 5841610
    Abstract: The invention is a miniature disc drive system. In the preferred embodiment of the invention, a positioner for positioning a transducer includes an actuator arm having the transducer mounted at one end and a voice coil motor (VCM) mounted at the other end. A pivot is centrally located along the actuator arm, whereby the VCM, when activated, can rotate the transducer over a disc or discs having approximately 45 mm diameters. The VCM is preferably a moving voice coil-type having a voice coil attached to the actuator arm and two magnets positioned above and below the voice coil such that the voice coil can freely move between them. One magnet is mounted to a base portion of a housing which encloses the entire disc drive system. The other magnet is mounted to roof portion of the housing. Thus, the housing is integrated into the active components of the disc drive and permits a significant size reduction to be achieved.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: November 24, 1998
    Assignee: Seagate Technology, Inc.
    Inventors: Ramgopal Battu, Iraj Jabbari, Sanjoy Ghose
  • Patent number: 5835310
    Abstract: The invention is a miniature disc drive system. In the preferred embodiment of the invention, a positioner for positioning a transducer includes an actuator arm having the transducer mounted at one end and a voice coil motor (VCM) mounted at the other end. A pivot is centrally located along the actuator arm, whereby the VCM, when activated, can rotate the transducer over a disc or discs having approximately 45 mm diameters. The VCM is preferably a moving voice coil-type having a voice coil attached to the actuator arm and two magnets positioned above and below the voice coil such that the voice coil can freely move between them. One magnet is mounted to a base portion of a housing which encloses the entire disc drive system. The other magnet is mounted to roof portion of the housing. Thus, the housing is integrated into the active components of the disc drive and permits a significant size reduction to be achieved.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: November 10, 1998
    Assignee: Seagate Technology, Inc.
    Inventors: Ramgopal Battu, Iraj Jabbari, Sanjoy Ghose
  • Patent number: 5808838
    Abstract: A disc drive system having at least one hard disc having concentric tracks is supported by a hub positioned in a centrally located aperture. The disc is rotated at a constant speed by a DC motor attached to the hub. A transducer head for communicating information with the hard disc is moved relative to the disc surface by a positioning apparatus. The positioning apparatus includes a voice coil motor for selectably and accurately positioning the transducer head over the tracks on the hard disc. The disc drive system is enclosed in a housing having a base portion and a roof portion. The positioning apparatus includes a shaft about which the transducer head rotates to move the transducer from track to track. In one configuration, permanent magnets are attached to the base and roof, and a moving coil is interposed between them, the housing completing a magnetic circuit in the VCM. In one aspect the disc drive system is designed to be permanently mounted in a portable, lap-top or notebook computer.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 15, 1998
    Assignee: Seagate Technologies, Inc.
    Inventors: Ramgopal Battu, Iraj Jabbari, Sanjoy Ghose
  • Patent number: 5333085
    Abstract: A read/write head gimbal is provided including a tab or extension on the end of the gimbal portion which is attached to the head/slider assembly, forming this tab such that, when the gimbal is assembled to the load beam, the formed tab passes through an opening created for this purpose in the load beam, and extends beyond the opening far enough to prevent its returning through the opening after the gimbal and load beam are spot welded together. The tab and opening in the load beam are dimensioned so that during normal read/write operations, there is no contact between the tab and the sides of the opening in the load beam. The tab/opening arrangement is such that shock forces in the direction of travel away from the load beam, or in parallel with the surface of the load beam bracing the gimbal, will result in contact between the tab and the sides of the opening in the load beam, thus preventing excessive motion of the gimbal which could result in permanent deformation of the gimbal.
    Type: Grant
    Filed: October 13, 1993
    Date of Patent: July 26, 1994
    Assignee: Seagate Technology, Inc.
    Inventors: Thomas R. Prentice, Robin O. Hammar, Sanjoy Ghose
  • Patent number: 5172282
    Abstract: The present invention proposes a memory device comprising a fixed disc on the surface of which data may be stored, and rotating transducers or heads which may be positioned to access any location on the disc. The rotating heads are mounted on transducer arms which are designed in such a manner that the transducer seeks outward as it is rotated. That is, similar to a flywheel governor in a steam engine, centrifugal force would impart a radial force on the arm which is movable in a low friction system along with the transducer, the radial force causing the transducer to move outward together with the radial arm with increasing rotational speed of the spindle motor.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: December 15, 1992
    Assignee: Seagate Technology, Inc.
    Inventor: Sanjoy Ghose
  • Patent number: 5051855
    Abstract: In a disc drive with an integrated casting comprising the housing for the stepper and spindle motors, the transducer is mounted on a normal bearing pivot assembly lightweight actuator arm and biasing strip spring. One end of the strip spring is mounted to a block and the effective force of the spring is aligned with the actuator arm running toward the stepper motor. The other, or head end of the actuator arm contains a gear sector having gear teeth on its face which mesh with a pinion on a motor shaft so rotation of the motor shaft across the face of the gear sector causes movement of the head mounting arm. The actuator arm is formed of a self-lubricating polymer or other lightweight self-lubricating material. This way, wear on the gear is reduced; and as the teeth are worn, the gear is still tightly biased against the pinion to maintain accurate movement of the actuator arm with rotation of the pinion.
    Type: Grant
    Filed: February 2, 1990
    Date of Patent: September 24, 1991
    Assignee: Seagate Technology, Inc.
    Inventors: Sanjoy Ghose, Enrique J. Klein, Efim Bronshvatch, Bernhard M. Seeger, Donald J. Macleod, Gunter K. Heine, Oswald Kuwert, Ramgopal Battu
  • Patent number: 4979063
    Abstract: A pivot bearing assembly for a disc drive including the combination of a bearing surrounded on one side by a wishbone-shaped end of the actuator arm, and on the other side by a biasing spring metal strip whose ends are tightly attached to the split ends of the wishbone of the actuator arm. When the arm assembly is mounted in the disc drive, the bearing is mounted on its center of rotation, with the spring tensile force biasing the head of the actuator arm against the spindle of the stepper motor. By providing the distal end of the actuator arm with a gear sector having gear teeth on its face which mesh with a pinion on the motor shaft of the stepper motor, rotation of the motor shaft across the face of the gear sector causes movement of the actuator arm and with it the flexure and transducer across the surface of the disc. The head arm supporting the flexure and transducer extends from the side of the actuator drive arm at a point near the stepper motor driven end of the drive arm, reducing head arm length.
    Type: Grant
    Filed: May 1, 1989
    Date of Patent: December 18, 1990
    Assignee: Seagate Technology, Inc.
    Inventors: Sanjoy Ghose, Ramgopal Battu, Iraj Jabbari
  • Patent number: 4896239
    Abstract: This invention provides a technique for effectively floating the rotor of a disc drive motor, thereby permitting small motions in the axial (non-critical) direction while maintaining significant stiffness in the radial (critical) direction. This is achieved by providing an electromagnetic actuator including a stepper motor having a housing, a stator located within the housing, and a rotor positionable relative to the stator driving a motor shaft to wind and unwind a band and thereby position the carriage. The drive shaft passes through ball bearings which support the shaft for rotation. The ball bearings themselves fit within an annular end bell portion of the motor housing which defines a channel for the bearing. An injected elastomer forms a tight-fitting ring between the bearings and the internal wall of the end bell, thereby radially supporting the outer race of the bearing.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: January 23, 1990
    Assignee: Seagate Technology, Inc.
    Inventor: Sanjoy Ghose
  • Patent number: 4881140
    Abstract: In a disc drive, the normal bearing pivot assembly is replaced with a combination of a lightweight actuator arm and biasing strip spring. One end of the strip spring is mounted to a block and the effective force of the spring is aligned with the actuator arm running toward the stepper motor. The other, or head end of the actuator arm contains a gear sector having gear teeth on its face which mesh with a pinion on a motor shaft so rotation of the motor shaft across the face of the gear sector causes movement of the head mounting arm.
    Type: Grant
    Filed: November 2, 1987
    Date of Patent: November 14, 1989
    Assignee: Seagate Technology, Inc.
    Inventors: Sanjoy Ghose, Efim Bronshvatch, Miles L. Peterson