Patents by Inventor Chao Long

Chao Long 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: 20050281160
    Abstract: A link writing method for a recordable or rewritable compact disk includes recording a writing interruption address and enabling a succeeding writing process after the writing interruption. Enabling a succeeding writing process includes searching the linking area and enabling a start writing signal and activating a laser power. The method can link a succeeding writing area with a previously written interrupted area with sufficient accuracy to allow the data frame to be successfully processed by error correction within the host drive. The linking area may be positioned by counting the values of the interrupted block, the interrupted data frame, and the interrupted bit count or by detecting a blank area. Other techniques for positioning the linking area include detecting an unwritten area having a length greater than a maximum or writing a characteristic pattern after an interruption.
    Type: Application
    Filed: August 29, 2005
    Publication date: December 22, 2005
    Inventors: Jyh-Shin Pan, Chao-Long Tsai
  • Publication number: 20050207297
    Abstract: A device and method for calibrating linear velocity and track pitch for an optical disc is disclosed. The device comprises a frequency divider, a synchronous bit-clock generator, a counter and a linear velocity and track pitch calculator. The frequency divider receives a motor frequency generator (FG) pulse and generates a motor rotation period signal (FG/X). The synchronous bit-clock generator generates a high frequency bit-clock according to a reproduced signal read from disc. The bit counter counts the pulse of the bit-clock for each period of the motor rotation period signal to generate the data amount M. The linear velocity and track pitch calculator calculates the linear velocity by a linear velocity function with the information of the data amount M and the motor rotation period. Then, the linear velocity and track pitch calculator calculates the track pitch by a pitch function with the information of the data amount, radius and linear velocity at different tracks.
    Type: Application
    Filed: May 5, 2005
    Publication date: September 22, 2005
    Applicant: MEDIATEK INC.
    Inventors: Chao-Long Tsai, Chi-Kwong Ho, Jin-Chuan Hsu
  • Patent number: 6928038
    Abstract: A circuit in an optical read/write device for protecting synchronizing patterns is proposed. The protection circuit utilizes a clock with constant frequency as a reference clock. The circuit for protecting synchronizing patterns of this present invention includes a SYNC detector, a frame period counter, a valid-frame-period judgment unit, a frame period memory, a window generator, a real SYNC judgment unit, a SYNC lock judgment unit, and a SYNC signal generator. The circuit counts the pulse number of a reference clock with constant frequency for each frame to get a constant frame period. Then, the circuit can correctly interpolate the lost frame SYNC signal immediately by counting the reference clock, when the disk is defected.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: August 9, 2005
    Assignee: Media Tek Inc.
    Inventors: Chao-Long Tsai, Andrew Chang, Szu-Shan Lo
  • Patent number: 6914862
    Abstract: A device and method for calibrating linear velocity and track pitch for an optical disc is disclosed. The device comprises a frequency divider, a synchronous bit-clock generator, a counter and a linear velocity and track pitch calculator. The frequency divider receives a motor frequency generator (FG) pulse and generates a motor rotation period signal (FG/X). The synchronous bit-clock generator generates a high frequency bit-clock according to a reproduced signal read from disc. The bit counter counts the pulse of the bit-clock for each period of the motor rotation period signal to generate the data amount M. The linear velocity and track pitch calculator calculates the linear velocity by a linear velocity function with the information of the data amount M and the motor rotation period. Then, the linear velocity and track pitch calculator calculates the track pitch by a pitch function with the information of the data amount, radius and linear velocity at different tracks.
    Type: Grant
    Filed: February 14, 2002
    Date of Patent: July 5, 2005
    Assignee: Mediatek Inc.
    Inventors: Chao-Long Tsai, Chi-Kwong Ho, Jin-Chuan Hsu
  • Publication number: 20050058046
    Abstract: A recording method and drive for optical storage media. The method inserts or replaces a special pattern in a recording EFM signal before the recording process is interrupted. Therefore, the special pattern is recorded either before or on the interrupted position. The starting position of the succeeding recording process is located by searching for the special pattern.
    Type: Application
    Filed: April 9, 2004
    Publication date: March 17, 2005
    Inventors: Jyh-Shin Pan, Chao-Long Tsai, Hong-Ching Chen
  • Publication number: 20040145982
    Abstract: The invention advantageously provides an apparatus and method for recovering clock signals extracted from prerecorded wobbled grooves formed in an optical storage medium such as a compact disk (CD), mini disk (MD) or digital video disk (DVD). A preferred embodiment of the method according to the invention primarily comprises the steps of extracting a series of wobble signals from the prerecorded information, demodulating the wobble signals for generating a series of demodulated clock signals, detecting a period for the clock signals, dividing each of the clock signals for acquiring a series of synchronization frames, generating compensating phases, and respectively adjusting the synchronization frames with the compensating phases for generating a series of phase compensated frames.
    Type: Application
    Filed: January 23, 2003
    Publication date: July 29, 2004
    Applicant: Media Tek Incorporation
    Inventors: Chao-Long Tsai, Jin-Bin Yang
  • Publication number: 20040022157
    Abstract: The invention provides a phase lock loop (PLL) in a controller of an optical disk system and methods therefor. According to a preferred embodiment of the invention, the PLL comprises a write phase detector, a read phase detector, and a common read/write module shared by the write and read phase detectors. Further according to the invention, the common read/write module comprises a read/write mode selector coupled to the write and read phase detectors, a charge pump coupled to the mode selector, a loop filter coupled to the charge pump, and a voltage control oscillator (VCO) coupled to the loop filter.
    Type: Application
    Filed: August 1, 2002
    Publication date: February 5, 2004
    Applicant: Media Tek Inc.
    Inventors: Tse-Hsiang Hsu, Chih-Cheng Chen, Chao Long Tsai
  • Publication number: 20030103428
    Abstract: An ATIP (absolute time in pre-groove) bit data generator free from an uneven duty cycle. The ATIP bit data generator includes an analog processor, a high-frequency clock generator, a first decoder, a sync pattern detector, and a second decoder. The analog processor receives a signal generated from an optical pickup, and further processes the signal to generate an ATIP FM signal. The high-frequency clock generator provides a high-frequency clock using the ATIP FM signal as a reference signal. The first decoder receives the ATIP FM signal and the high-frequency clock and generates bi-phase data. The sync pattern detector receives the bi-phase data and the high-frequency clock, and generates a sync indication signal. The second decoder counts the pulse number of the high-frequency clock for each counting cycle, and the counting cycle includes a plurality of half periods of the ATIP FM signal.
    Type: Application
    Filed: November 25, 2002
    Publication date: June 5, 2003
    Inventors: Ping-Hsing Lu, Yao-Jen Liang, Chao-Long Tsai
  • Publication number: 20020172111
    Abstract: A circuit in an optical read/write device for protecting synchronizing patterns is proposed. The protection circuit utilizes a clock with constant frequency as a reference clock. The circuit for protecting synchronizing patterns of this present invention includes a SYNC detector, a frame period counter, a valid-frame-period judgment unit, a frame period memory, a window generator, a real SYNC judgment unit, a SYNC lock judgment unit, and a SYNC signal generator. The circuit counts the pulse number of a reference clock with constant frequency for each frame to get a constant frame period. Then, the circuit can correctly interpolate the lost frame SYNC signal immediately by counting the reference clock, when the disk is defected.
    Type: Application
    Filed: May 7, 2002
    Publication date: November 21, 2002
    Inventors: Chao-Long Tsai, Andrew Chang, Szu-Shan Lo
  • Patent number: 6465447
    Abstract: This invention provides a separation method by which a compound having an antitumor effect possessed by Tochukaso can be obtained in a pure state. Further, this invention reveals the chemical structure of the compound having such antitumor effect. Still further, the invention aims at providing an antitumor agent comprising said compound.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: October 15, 2002
    Assignee: Hisamitsu Pharmaceuticals Co., Inc.
    Inventors: Tair-Long Pan, Sigeru Goto, Chao-Long Chen
  • Publication number: 20020145961
    Abstract: A device and method for calibrating linear velocity and track pitch for an optical disc is disclosed. The device comprises a frequency divider, a synchronous bit-clock generator, a counter and a linear velocity and track pitch calculator. The frequency divider receives a motor frequency generator (FG) pulse and generates a motor rotation period signal (FG/X). The synchronous bit-clock generator generates a high frequency bit-clock according to a reproduced signal read from disc. The bit counter counts the pulse of the bit-clock for each period of the motor rotation period signal to generate the data amount M. The linear velocity and track pitch calculator calculates the linear velocity by a linear velocity function with the information of the data amount M and the motor rotation period. Then, the linear velocity and track pitch calculator calculates the track pitch by a pitch function with the information of the data amount, radius and linear velocity at different tracks.
    Type: Application
    Filed: February 14, 2002
    Publication date: October 10, 2002
    Inventors: Chao-Long Tsai, Chi-Kwong Ho, Jin-Chuan Hsu
  • Publication number: 20020048240
    Abstract: The invention provides a link writing method for a recordable compact disk (CD-R) and a driver for using the method. The link writing method includes the steps of “recording a writing interruption address”, and “enabling a succeeding writing process” when the causes resulting in the writing interruption is eliminated. The step of “enabling a succeeding writing process” includes the steps of “searching the linking area” and “enabling a start writing signal and activating a laser power”. The purpose of the invention is to accurately link the succeeding writing area with the written interrupted area to keep the length of the data frame consistent without causing errors on data reading. The linking area is positioned either by counting the values of the interrupted block, the interrupted data frame, and the interrupted bit count or by detecting a blank area.
    Type: Application
    Filed: March 8, 2001
    Publication date: April 25, 2002
    Inventors: Jyh-Shin Pan, Chao-Long Tsai
  • Patent number: 6055219
    Abstract: A method is provided for use on an optical disc drive, which can automatically detect the current radial position of the pickup head to thereby switch the motor operation between the CLV (constant linear velocity) mode and the CAV (constant angular velocity) mode for optimal performance of the optical disc drive. The current radial position of the pickup head is detected by using CLV and CAV position estimating means. If the current radial position of the pickup head is at a preset switching point, the mode of operation is switched from the current one to the other. Moreover, the reference signals used in the respective modes are adaptively varied so as to allow the data transfer rate of the data read operation on the optical disc to be consistent in both modes without interrupting the reading and transferring of the data from the optical disc. The method can thus allow the benefits of a high data transfer rate, short seek time, and low power consumption by the optical disc drive.
    Type: Grant
    Filed: April 30, 1998
    Date of Patent: April 25, 2000
    Assignee: Mediatek, Inc.
    Inventors: Chi-Kwong Ho, Chao-Long Tsai