Patents by Inventor Prakash Balasubramaniam

Prakash Balasubramaniam 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).

  • Patent number: 10991387
    Abstract: A data storage device is disclosed comprising a non-energy assist (NEA) head configured to access a first disk surface, and an energy assist (EA) head configured to access a second disk surface. The data storage device further comprises control circuitry configured to write data to the first disk surface, and migrate at least part of the data to the second disk surface.
    Type: Grant
    Filed: March 27, 2020
    Date of Patent: April 27, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: Prakash Balasubramaniam, David R. Hall
  • Patent number: 10562068
    Abstract: The present invention relates a power ultrasound device for fluids processing. An ultrasonic resonator comprises: an exciter section having a longitudinal axis and dimensioned to be resonant in a direction along the longitudinal axis when the exciter section is energized with high frequency vibrations; and a radiator section having a connection stub and coupled to the exciter section through the connection stub, wherein the radiator section is configured to receive the vibrations from the exciter section and transmit the vibrations as acoustic waves, wherein an axial length of the exciter section is less than a half-wavelength, wherein the connection stub completes the half-wavelength when coupled to the excited section to allow the ultrasonic resonator operate in resonance at design frequency.
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: February 18, 2020
    Assignee: SEMBCORP MARINE REPAIRS & UPGRADES PTD. LTD.
    Inventors: Hafiiz Bin Osman, Margaret Lucas, Fannon Chwee Ning Lim, Prakash Balasubramaniam
  • Publication number: 20180287585
    Abstract: The present invention relates a power ultrasound device for fluids processing. An ultrasonic resonator comprises: an exciter section having a longitudinal axis and dimensioned to be resonant in a direction along the longitudinal axis when the exciter section is energized with high frequency vibrations; and a radiator section having a connection stub and coupled to the exciter section through the connection stub, wherein the radiator section is configured to receive the vibrations from the exciter section and transmit the vibrations as acoustic waves, wherein an axial length of the exciter section is less than a half-wavelength, wherein the connection stub completes the half-wavelength when coupled to the excited section to allow the ultrasonic resonator operate in resonance at design frequency.
    Type: Application
    Filed: March 31, 2017
    Publication date: October 4, 2018
    Inventors: Hafiiz Bin OSMAN, Margaret LUCAS, Fannon Chwee Ning LIM, Prakash BALASUBRAMANIAM
  • Patent number: 9972344
    Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser and a first write operation is executed to write first data to the first disk surface during a first revolution of the first disk surface. A first transient decrease in an output power of the laser is detected during the first write operation, and when the first transient decrease in the output power of the laser is detected during the first write operation, a write-verify of the first data is executed during a second revolution of the first disk surface.
    Type: Grant
    Filed: July 24, 2017
    Date of Patent: May 15, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Galvin Chia, Prakash Balasubramaniam, Phillip S. Haralson, Dennis W. Hogg
  • Publication number: 20170323657
    Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser and a first write operation is executed to write first data to the first disk surface during a first revolution of the first disk surface. A first transient decrease in an output power of the laser is detected during the first write operation, and when the first transient decrease in the output power of the laser is detected during the first write operation, a write-verify of the first data is executed during a second revolution of the first disk surface.
    Type: Application
    Filed: July 24, 2017
    Publication date: November 9, 2017
    Inventors: HUANXIANG RUAN, GALVIN CHIA, PRAKASH BALASUBRAMANIAM, PHILLIP S. HARALSON, DENNIS W. HOGG
  • Patent number: 9747928
    Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser when executing a first write operation, and the first write operation is paused when a transient increase in the output power of the laser is detected. In another embodiment, a write-verify of the written data is executed when a transient decrease in the output power of the laser is detected.
    Type: Grant
    Filed: September 25, 2014
    Date of Patent: August 29, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Galvin Chia, Prakash Balasubramaniam, Phillip S. Haralson, Dennis W. Hogg
  • Patent number: 9099144
    Abstract: A disk drive is disclosed comprising a disk and a head comprising a laser configured to heat the disk while writing to the disk. Data is written to the disk using an operating laser power applied to the laser, and then the data is read from the disk to generate a read signal. A ramp interval is measured for an amplitude of the first read signal to ramp up to a first threshold.
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: August 4, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Galvin T. Chia, Prakash Balasubramaniam
  • Patent number: 9042045
    Abstract: A disk drive is disclosed including a disk having a plurality of sectors, and a head actuated over the disk. A defect threshold is initialized, and a first sector is read to generate a first read signal. The first read signal is processed to detect a defect in the first sector relative to the defect threshold. After detecting the defect, the defect threshold is adjusted and the first sector is reread to generate a second read signal. The second read signal is processed to detect the defect in the first sector relative to the adjusted defect threshold.
    Type: Grant
    Filed: November 1, 2007
    Date of Patent: May 26, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Dean V. Dang, Kek Ming Chua, King S. Goh, Prakash Balasubramaniam, Ming Jin
  • Patent number: 8711506
    Abstract: A disk drive is disclosed comprising a disk comprising a plurality of servo tracks defined by servo sectors. The disk drive further comprises a head comprising a read element offset linearly from a write element by a gap such that when the disk rotates, the read element reaches a servo sector before the write element. During a first operation, a first length of a beginning of the servo sector is read, and during a write operation, a second length of the beginning of the servo sector shorter than the first length is read to enable data to be written while the read element is over at least part of the servo sector.
    Type: Grant
    Filed: May 31, 2012
    Date of Patent: April 29, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Davide Giovenzana, John W. Vanlaanen, Prakash Balasubramaniam, Teik Ee Yeo, Guoxiao Guo, Honge Wang, Jie Yu, Philip S. Gordon