Patents Assigned to Leadis Technology, Inc.
  • Patent number: 7358939
    Abstract: An organic light-emitting diode display driver adjusts the display scan period of the current driving the organic light-emitting diodes of a selected row based upon the sum of the display data corresponding to the selected row, thereby removing crosstalk in the OLED display panel. The driver includes an adder for adding the display data corresponding to the selected row and a scan period look-up table storing display scan period values. The scan period look-up table is configured such that it outputs display scan period values substantially proportional or inversely proportional to the sum of the display data to remove bright crosstalk or dark crosstalk, respectively, in the OLED display panel.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: April 15, 2008
    Assignee: Leadis Technology, Inc.
    Inventors: Chang Oon Kim, Chan Young Jeong, Young Seok Sohn, Jeong Hwan Lee
  • Publication number: 20080068079
    Abstract: An amplifier system having one or more signal paths. Each path includes a phase amplifier and a Class G Type amplifier. The phase amplifier receives an input signal bearing phase information. The Class G Type amplifier receives an envelope signal bearing amplitude information. The output of the Class G Type amplifier is coupled to provide the VCC reference for the phase amplifier. Thus, the output signal of the phase amplifier bears both phase and amplitude information. High frequency performance and high efficiency are obtained.
    Type: Application
    Filed: March 20, 2007
    Publication date: March 20, 2008
    Applicant: Leadis Technology, Inc.
    Inventor: Cary L. Delano
  • Publication number: 20080068074
    Abstract: An amplifier system having one or more signal paths. Each path includes a linear amplifier and a Class G Type amplifier. The linear amplifier receives an input signal bearing phase and amplitude information. The Class G Type amplifier receives an envelope signal which tracks the anticipated output signal, plus a DC offset. The output of the Class G Type amplifier is coupled to provide the VCC reference for the linear amplifier. High frequency performance and high efficiency are obtained.
    Type: Application
    Filed: March 20, 2007
    Publication date: March 20, 2008
    Applicant: Leadis Technology, Inc.
    Inventor: Cary L. Delano
  • Publication number: 20080019546
    Abstract: An audio amplifier system having improved power efficiency by wasting less power in its bias voltage circuit. An amplifier provides a voice signal to a first (+) input of a loudspeaker and a high efficiency converter provides a bias voltage to a second (?) input of the loudspeaker. In multi-loudspeaker systems, a single high efficiency converter can bias all the loudspeakers at a common node. The high efficiency converter can be a charge pump or a buck converter or the like, and has greater than 90% efficiency.
    Type: Application
    Filed: March 20, 2007
    Publication date: January 24, 2008
    Applicant: Leadis Technology, Inc.
    Inventors: Cary Delano, William Chester
  • Publication number: 20080007337
    Abstract: An improved Class G type amplifier which switches between multiple power rails depending upon the instantaneous amplitude of the input signal versus the power rails. The low voltage (inner) amplifier includes a plurality of parallel amplifier devices, and the high voltage (outer) amplifier includes a plurality of parallel amplifier devices. A plurality of switches each couples the input signal to either a respective one of the inner amplifier devices or a respective one of the outer amplifier devices. The switches are activated sequentially, such that the switching from inner to outer amplifier devices or vice versa is staggered over some period of time. This avoids having a single, large glitch in the output, and spreads multiple smaller glitches over enough time that some of the glitch energy can fall within the frequency range where the amplifier's feedback circuitry can eliminate its noise. The switches are sequentially activated by a series of delay elements.
    Type: Application
    Filed: March 20, 2007
    Publication date: January 10, 2008
    Applicant: Leadis Technology, Inc.
    Inventor: Brian North
  • Publication number: 20070285176
    Abstract: A phase-slipping phase-locked loop which generates an output signal whose frequency is a non-integer multiple of a reference frequency. The PLL has a first input for receiving a first binary value i which specifies an integer portion of the frequency multiplier, and a second input for receiving a second binary value f which specifies a fractional portion of the frequency multiplier. A multi-phase VCO has a plurality v of outputs on equal phase shifted spacing. The phase slipping is applied every i cycles, and the second binary value f specifies a phase slip stride, such that the frequency multiplier equals i+f/v.
    Type: Application
    Filed: March 20, 2007
    Publication date: December 13, 2007
    Applicant: Leadis Technology, Inc.
    Inventor: Brian North
  • Publication number: 20070236294
    Abstract: A new Class L amplifier which dynamically switches between multiple pairs of power rails, and has the ability to select the most advantageous combination of rails for the minimization of power dissipation in the amplifier. A bridged amplifier system using two Class L amplifiers to drive a load.
    Type: Application
    Filed: March 20, 2007
    Publication date: October 11, 2007
    Applicant: Leadis Technology, Inc.
    Inventor: Cary Delano
  • Publication number: 20070236295
    Abstract: An RF power amplification system having a power amplifier, a matching network, and an antenna power controller which compares a voltage at the matching network output to a voltage at the matching network input and uses a result of that comparison to manipulate the power amplifier and/or the matching network, to control the power applied to the antenna. In one embodiment, the power controller tristates one or more of a plurality of parallel power amplifier devices in the amplifier, to control the antenna power. In another embodiment, the power controller manipulates a plurality of parallel resistors or other impedances in the power amplifier, switching some impedances in and some impedances out, to maximize the power coupling to the antenna or to operate the amplifier device in a maximally efficient operating range.
    Type: Application
    Filed: March 20, 2007
    Publication date: October 11, 2007
    Applicant: Leadis Technology, Inc.
    Inventor: Cary Delano
  • Publication number: 20070223738
    Abstract: An audio amplifier such as for driving headphones. The amplifier includes multiple amplifier devices coupled in parallel. Both a bias generator and a volume control are responsive to a user setting. Under low output signal conditions, one or more of the amplifier devices are disabled in response to the user setting. Disabled amplifier devices do not consume output bias current. Thus the audio amplifier has reduced power consumption, and the system has longer battery life.
    Type: Application
    Filed: March 20, 2007
    Publication date: September 27, 2007
    Applicant: Leadis Technology, Inc.
    Inventor: Brian North
  • Patent number: 7068248
    Abstract: A single-chip column driver for organic light emitting diode (OLED) display is disclosed. Instead of using two column drivers for dual scan, the present invention uses one column driver driving both the upper and the lower OLED panels. The column driver has a two set of output circuitry: one for driving the upper panel and the other for driving the lower panel. The single chip solution of the present invention eliminates the problem of display uniformity without increasing the part count. The invention also enables independent control of RGB without further increasing the part count.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: June 27, 2006
    Assignee: Leadis Technology, Inc.
    Inventors: Sung Tae Ahn, Keunmyung Lee, Dae Young Ahn, Tae Kwang Park
  • Patent number: 7046222
    Abstract: A single scan driver for an organic light emitting diode (OLED) display is disclosed, that can reduce the required power consumption. By connecting together both ends of each column line so that a single driver circuit can drive both ends of each column line together, the column line resistance is reduced, resulting in a significant reduction in power consumption.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: May 16, 2006
    Assignee: Leadis Technology, Inc.
    Inventors: Chang Oon Kim, Keunmyung Lee
  • Patent number: 7015889
    Abstract: A scheme to reduce output variations in a column driver for a flat-panel display by sharing the characteristics of analog circuit is disclosed. An input multiplexer is provided between two neighboring digital inputs, and an output multiplexer is provided between two neighboring analog outputs so that the characteristics of neighboring analog circuits can be shared by multiplexing. The averaging effect by sharing reduces variations in the output. The multiplexing may be done either in time division or on a frame-by-frame basis.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: March 21, 2006
    Assignee: Leadis Technology, Inc.
    Inventors: Sung Tae Ahn, Yung Jin Jeon, Chan Young Jeong, Keunmyung Lee
  • Patent number: 6919872
    Abstract: A driver for driving an STN LCD is disclosed. A preferred embodiment comprises a 3-line output display data for storing display data, an XOR block for finding mismatches between each 3-line output set of the stored display and orthogonal function signals, a decoder block for calculating mismatch numbers, a level shifter block for shifting the data level of the mismatch numbers to another level, and a voltage selector block for selecting a voltage level from 2 levels of voltage. Because data latches and output latches are not necessary, the driver of the present invention achieves significant reduction in the circuit components and chip size without compromising the display quality.
    Type: Grant
    Filed: February 25, 2002
    Date of Patent: July 19, 2005
    Assignee: Leadis Technology, Inc.
    Inventors: Tae-Kwang Park, Keunmyung Lee