Patents by Inventor Andrew M. Kameya

Andrew M. Kameya 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: 8599915
    Abstract: First information is received at a first pulse width modulation (PWM) module responsive to a chip select signal being asserted at a chip select input of a communication bus of the first PWM module during a first time. The first information is latched at a control register of the first PWM module in response to a first logic transition of the chip select signal. A first PWM signal is provided at a first output of the first PWM module beginning a predetermined amount of time after the first logic transition of the chip select signal, the first PWM signal generated by the first PWM module based upon the first information.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: December 3, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Andrew M. Kameya, Weizhuang W. Xin
  • Patent number: 8373643
    Abstract: A PWM generation module generates a PWM data signal used to control a light emitting diode (LED) driver for one or more strings of LEDs of a display device. The PWM data signal is synchronized with the frame boundaries of the video content being displayed. The PWM generation module can configure the PWM data signal such that a new PWM cycle is initiated at the start of each successive frame, and further whereby those PWM cycles that would be prematurely terminated at frame boundaries are instead driven at a constant reference level until the frame boundary. With this configuration, a substantially linear average light intensity can be achieved across frames, thereby reducing or eliminating display distortion that is often present in other PWM cycle synchronization techniques.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: February 12, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Andrew M. Kameya, Victor K. Lee
  • Patent number: 8279144
    Abstract: Disclosed are example techniques for frame-based power management in a light emitting diode (LED) system having a plurality of LED strings. A voltage source provides an output voltage to drive the LED strings. An LED driver generates a frame timing reference representative of the frame rate or display timing of a series of image frames to be displayed via the LED system. An update reference is generated from the frame timing reference. The LED driver monitors one or more operating parameters of the LED system. In response to update triggers marked by the update reference, the LED driver adjusts the output voltage of the voltage source based on the status of each of the one or more monitored operating parameters (either from the previous update period or determined in response to the update trigger), thereby synchronizing the updating of the output voltage to the frame rate (or a virtual approximation of the frame rate) of the video being displayed.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: October 2, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Andrew M Kameya, Jan Krellner, Kenneth C. Kwok, Victor K. Lee, Weizhuang W. Xin
  • Publication number: 20120207205
    Abstract: First information is received at a first pulse width modulation (PWM) module responsive to a chip select signal being asserted at a chip select input of a communication bus of the first PWM module during a first time. The first information is latched at a control register of the first PWM module in response to a first logic transition of the chip select signal. A first PWM signal is provided at a first output of the first PWM module beginning a predetermined amount of time after the first logic transition of the chip select signal, the first PWM signal generated by the first PWM module based upon the first information.
    Type: Application
    Filed: February 11, 2011
    Publication date: August 16, 2012
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Bin Zhao, Jack W. Cornish, Andrew M. Kameya, Weizhuang W. Xin
  • Patent number: 8228098
    Abstract: A pulse width modulation (PWM) frequency converter converts an input PWM signal to an output PWM signal having a different frequency while maintaining a substantially equal duty ratio. The PWM frequency converter samples the input PWM signal for a PWM cycle using a sampling clock. A filter module filters the resulting set of one or more PWM parameters to compensate for noise introduced by potential clock mismatch, clock jitter, ambient variations, and other non-deterministic issues, thereby generating filtered PWM parameters. The sampling employed by the filter module compares a difference between the one or more current PWM parameters and previous (or historical) PWM parameters from an earlier sampled PWM cycle to a predetermined change threshold in determining a filtered set of one or more PWM parameters. The filtered set of one or more PWM parameters then is used to generate one or more corresponding PWM cycles of the output signal.
    Type: Grant
    Filed: August 7, 2009
    Date of Patent: July 24, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Andrew M. Kameya, Victor K. Lee
  • Patent number: 8188771
    Abstract: A pulse width modulation (PWM) frequency converter converts an input PWM signal to an output PWM signal having a different frequency while maintaining a substantially equal duty ratio. The PWM frequency converter samples the input PWM signal for a PWM cycle using a sampling clock. A filter module filters the resulting set of one or more PWM parameters to compensate for noise introduced by potential clock mismatch, clock jitter, ambient variations, and other non-deterministic issues, thereby generating filtered PWM parameters. The sampling employed by the filter module compares a difference between the one or more current PWM parameters and previous (or historical) PWM parameters from an earlier sampled PWM cycle to a predetermined change threshold in determining a filtered set of one or more PWM parameters. The filtered set of one or more PWM parameters then is used to generate one or more corresponding PWM cycles of the output signal.
    Type: Grant
    Filed: August 7, 2009
    Date of Patent: May 29, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Andrew M. Kameya, Victor K. Lee
  • Patent number: 8115414
    Abstract: Techniques for dynamic headroom control in a light emitting diode (LED) system are disclosed. An output voltage is provided to drive a plurality of LED strings. A feedback controller monitors the tail voltages of the LED strings to identify the minimum tail voltage and adjusts the output voltage based on the lowest tail voltage. The LED strings grouped into subsets and the feedback controller is segmented such that, for a certain duration, a minimum tail voltage is determined for each subset. The minimum tail voltages of the subsets are used to determine the overall minimum tail voltage of the plurality of LED strings for the certain duration so as to control the output voltage in the following duration. The segments of the feedback controller can be implemented in separate integrated circuit (IC) packages, thereby facilitating adaptation to different numbers of LED strings by integrating the corresponding number of IC packages.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: February 14, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Victor K. Lee, Andrew M. Kameya
  • Patent number: 8106604
    Abstract: A light emitting diode (LED) system implements a LED driver to drive a set of one or more LED strings. The LED driver includes a voltage source to provide an adjustable output voltage to a head end of each LED string of the set for a first duration and a second duration following the first duration. The LED driver further includes a feedback controller to control the voltage source to adjust the output voltage for the second duration based on a digital code value generated from a minimum tail voltage of one or more tail voltages of the set at a sample point of the first duration. The LED driver further includes a power controller to temporarily enable one or more components of the feedback controller for a sample period of the first duration, the sample period comprising the sample point.
    Type: Grant
    Filed: July 16, 2009
    Date of Patent: January 31, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Andrew M. Kameya, Kenneth C. Kwok, Victor K. Lee
  • Patent number: 8049439
    Abstract: A voltage source provides an output voltage to drive a plurality of light emitting diode (LED) strings. A LED driver adjusts the level of the output voltage so as to maintain the lowest tail voltage of the LED strings at or near a predetermined threshold voltage so as provide sufficient headroom voltages for current regulators for the LED strings. The LED driver operates in an operational mode and a calibration mode, which can be implemented in parallel with, or part of, the operational mode. During the calibration mode, the LED driver determines, for each LED string, a code value representative of the level of the output voltage necessary to maintain the tail voltage of the corresponding LED string at or near the predetermined threshold voltage. In the operational mode, the code values from the calibration mode are used to control the voltage source to provide an appropriate level for the output voltage.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: November 1, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Victor K. Lee, Andrew M. Kameya
  • Patent number: 8035315
    Abstract: Power management in a light emitting diode (LED) system having a plurality of LED strings is disclosed. A voltage source provides an output voltage to drive a plurality of LED strings. An LED driver implements a feedback mechanism to monitor the tail voltages of the active LED strings to identify the minimum tail voltage and adjust the output voltage of the voltage source based on the lowest tail voltage. A loop calibration module of the LED driver calibrates the feedback mechanism of the LED driver based on a relationship between a digital code value used to generate a particular output voltage and another digital code value generated based on the minimum tail voltage resulting from the particular output voltage.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: October 11, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Andrew M. Kameya, Jan Krellner, Kenneth C. Kwok, Victor K. Lee, Weizhuang W. Xin
  • Publication number: 20110032008
    Abstract: A pulse width modulation (PWM) frequency converter converts an input PWM signal to an output PWM signal having a different frequency while maintaining a substantially equal duty ratio. The PWM frequency converter samples the input PWM signal for a PWM cycle using a sampling clock. A filter module filters the resulting set of one or more PWM parameters to compensate for noise introduced by potential clock mismatch, clock jitter, ambient variations, and other non-deterministic issues, thereby generating filtered PWM parameters. The sampling employed by the filter module compares a difference between the one or more current PWM parameters and previous (or historical) PWM parameters from an earlier sampled PWM cycle to a predetermined change threshold in determining a filtered set of one or more PWM parameters. The filtered set of one or more PWM parameters then is used to generate one or more corresponding PWM cycles of the output signal.
    Type: Application
    Filed: August 7, 2009
    Publication date: February 10, 2011
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Andrew M. Kameya, Victor K. Lee
  • Patent number: 7825610
    Abstract: Power management in a light emitting diode (LED) system having a plurality of LED strings is disclosed. A voltage source provides an output voltage to drive the LED strings. An LED driver monitors the tail voltages of the active LED strings to identify the minimum, or lowest, tail voltage and adjusts the output voltage of the voltage source based on the lowest tail voltage. The LED driver can adjust the output voltage so as to maintain the lowest tail voltage at or near a predetermined threshold voltage so as to ensure that the output voltage is sufficient to properly drive each active LED string with a regulated current in view of pulse width modulation (PWM) performance requirements without excessive power consumption.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: November 2, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Victor K. Lee, Andrew M. Kameya
  • Publication number: 20100194308
    Abstract: A voltage source provides an output voltage to drive a plurality of light emitting diode (LED) strings. A LED driver adjusts the level of the output voltage so as to maintain the lowest tail voltage of the LED strings at or near a predetermined threshold voltage so as provide sufficient headroom voltages for current regulators for the LED strings. The LED driver operates in an operational mode and a calibration mode, which can be implemented in parallel with, or part of, the operational mode. During the calibration mode, the LED driver determines, for each LED string, a code value representative of the level of the output voltage necessary to maintain the tail voltage of the corresponding LED string at or near the predetermined threshold voltage. In the operational mode, the code values from the calibration mode are used to control the voltage source to provide an appropriate level for the output voltage.
    Type: Application
    Filed: January 30, 2009
    Publication date: August 5, 2010
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Victor K. Lee, Andrew M. Kameya
  • Publication number: 20100156315
    Abstract: Power management in a light emitting diode (LED) system having a plurality of LED strings is disclosed. A voltage source provides an output voltage to drive a plurality of LED strings. An LED driver implements a feedback mechanism to monitor the tail voltages of the active LED strings to identify the minimum tail voltage and adjust the output voltage of the voltage source based on the lowest tail voltage. A loop calibration module of the LED driver calibrates the feedback mechanism of the LED driver based on a relationship between a digital code value used to generate a particular output voltage and another digital code value generated based on the minimum tail voltage resulting from the particular output voltage.
    Type: Application
    Filed: December 22, 2008
    Publication date: June 24, 2010
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Andrew M. Kameya, Jan Krellner, Kenneth C. Kwok, Victor K. Lee, Weizhuang W. Xin
  • Publication number: 20100085295
    Abstract: A PWM generation module generates a PWM data signal used to control a light emitting diode (LED) driver for one or more strings of LEDs of a display device. The PWM data signal is synchronized with the frame boundaries of the video content being displayed. The PWM generation module can configure the PWM data signal such that a new PWM cycle is initiated at the start of each successive frame, and further whereby those PWM cycles that would be prematurely terminated at frame boundaries are instead driven at a constant reference level until the frame boundary. With this configuration, a substantially linear average light intensity can be achieved across frames, thereby reducing or eliminating display distortion that is often present in other PWM cycle synchronization techniques.
    Type: Application
    Filed: October 3, 2008
    Publication date: April 8, 2010
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Andrew M. Kameya, Victor K. Lee
  • Publication number: 20100026203
    Abstract: Disclosed are example techniques for frame-based power management in a light emitting diode (LED) system having a plurality of LED strings. A voltage source provides an output voltage to drive the LED strings. An LED driver generates a frame timing reference representative of the frame rate or display timing of a series of image frames to be displayed via the LED system. An update reference is generated from the frame timing reference. The LED driver monitors one or more operating parameters of the LED system. In response to update triggers marked by the update reference, the LED driver adjusts the output voltage of the voltage source based on the status of each of the one or more monitored operating parameters (either from the previous update period or determined in response to the update trigger), thereby synchronizing the updating of the output voltage to the frame rate (or a virtual approximation of the frame rate) of the video being displayed.
    Type: Application
    Filed: July 31, 2008
    Publication date: February 4, 2010
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Andrew M. Kameya, Jan Krellner, Kenneth C. Kwok, Victor K. Lee, Weizhuang W. Xin
  • Publication number: 20090273288
    Abstract: A light emitting diode (LED) system implements a LED driver to drive a set of one or more LED strings. The LED driver includes a voltage source to provide an adjustable output voltage to a head end of each LED string of the set for a first duration and a second duration following the first duration. The LED driver further includes a feedback controller to control the voltage source to adjust the output voltage for the second duration based on a digital code value generated from a minimum tail voltage of one or more tail voltages of the set at a sample point of the first duration. The LED driver further includes a power controller to temporarily enable one or more components of the feedback controller for a sample period of the first duration, the sample period comprising the sample point.
    Type: Application
    Filed: July 16, 2009
    Publication date: November 5, 2009
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Andrew M. Kameya, Kenneth C. Kwok, Victor K. Lee
  • Publication number: 20090230891
    Abstract: Power management in a light emitting diode (LED) system having a plurality of LED strings is disclosed. A voltage source provides an output voltage to drive the LED strings. An LED driver monitors the tail voltages of the active LED strings to identify the minimum, or lowest, tail voltage and adjusts the output voltage of the voltage source based on the lowest tail voltage. The LED driver can adjust the output voltage so as to maintain the lowest tail voltage at or near a predetermined threshold voltage so as to ensure that the output voltage is sufficient to properly drive each active LED string with a regulated current in view of pulse width modulation (PWM) performance requirements without excessive power consumption.
    Type: Application
    Filed: March 26, 2008
    Publication date: September 17, 2009
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Victor K. Lee, Andrew M. Kameya
  • Publication number: 20090230874
    Abstract: Techniques for dynamic headroom control in a light emitting diode (LED) system are disclosed. An output voltage is provided to drive a plurality of LED strings. A feedback controller monitors the tail voltages of the LED strings to identify the minimum tail voltage and adjusts the output voltage based on the lowest tail voltage. The LED strings grouped into subsets and the feedback controller is segmented such that, for a certain duration, a minimum tail voltage is determined for each subset. The minimum tail voltages of the subsets are used to determine the overall minimum tail voltage of the plurality of LED strings for the certain duration so as to control the output voltage in the following duration. The segments of the feedback controller can be implemented in separate integrated circuit (IC) packages, thereby facilitating adaptation to different numbers of LED strings by integrating the corresponding number of IC packages.
    Type: Application
    Filed: January 30, 2009
    Publication date: September 17, 2009
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Bin Zhao, Jack W. Cornish, Brian B. Horng, Victor K. Lee, Andrew M. Kameya
  • Patent number: 5187591
    Abstract: Modulated data information having an individual one of different baud rates and aural information are converted at a transmitter from analog to digital form. A controller separately identifies the digitized aural and modulated data information and, if modulated data, identifies the baud rate of such modulated data. The aural information is separately transformed. For modulated data, the information is separately processed in accordance with the different baud rates. The individual ones of aural and modulated data are then introduced to a common line for packetizing. The beginning of each packet is labelled to identify whether the packet contains aural information (such as voice or music) or modulated data (such as modem or facsimile), and, if modulated data, the particular baud rate of such information. An individual code identifies the end of each packet. The packetized information is then multiplexed in a common bus with other packetized aural and data information.
    Type: Grant
    Filed: January 24, 1991
    Date of Patent: February 16, 1993
    Assignee: Micom Communications Corp.
    Inventors: Kenneth R. Guy, Andrew M. Kameya, Herbert M. Wildfeuer