Patents by Inventor Chang-Long Wu
Chang-Long Wu 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).
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Publication number: 20120113780Abstract: An apparatus for accessing data from a disc with a linking area comprises a pick up head, a servo, a processing unit, a position predictor, and a control signal generator. The pick up head reads data from the disc and generates a read signal. The servo controls the pick up head. The processing unit processes the read signal and controls the servo according to a plurality of control signals. The position predictor tracks time position on the disc and generates position information. The control signal generator receives the position information and generates the control signals according to the position information.Type: ApplicationFiled: January 17, 2012Publication date: May 10, 2012Applicant: MEDIATEK INC.Inventors: Chang-Long WU, Shu-Hung CHOU
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Patent number: 8023370Abstract: An apparatus for converting a groove/land polarity on an optical medium, comprises a physical identification (PID) detector for detecting a first PID value from a first sector, a sector information unit for providing an information which includes a second PID value indicative of either a second sector or at least one reference groove/land changing point, a sector counter for counting a first value whose an initiation is set by the sector information unit based on the information and/or by the PID detector based on the first PID value, and a comparing unit for determining at least one oncoming groove/land changing points, when the first value approaches a second value predetermined in or generated by the sector information unit according to the information.Type: GrantFiled: July 29, 2009Date of Patent: September 20, 2011Assignee: MEDIATEK Inc.Inventors: Meng-Hsueh Lin, Chang-long Wu
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Publication number: 20110167323Abstract: The invention discloses an error-correcting apparatus for decoding an input signal by using a Viterbi algorithm to generate a Viterbi-decoded signal, including an erasure unit and a decoder. The erasure unit is configured to generate at least one logic signal according to at least one path metric difference of path metrics in the Viterbi algorithm, and generate erasure information, wherein the erasure information indicates data reliability of at least one location of the Viterbi-decoded signal. The decoder is configured to decode the Viterbi-decoded signal according to the erasure information.Type: ApplicationFiled: January 7, 2010Publication date: July 7, 2011Applicant: MEDIATEK INC.Inventors: Chih-Ching Yu, Pi-Hai Liu, Yu-Hsuan Lin, Chang-Long Wu, Hong-Ching Chen
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Patent number: 7903508Abstract: A system for determining groove/land (G/L) switching points of an optical disc is disclosed. The system includes a motor rotating signal generating apparatus, an detection apparatus, and a G/L switching point generating apparatus. The motor rotating signal generating apparatus is for sensing the rotation of a motor to generate a motor rotating signal with a period corresponding to the rotation of the optical disc. Also, the detection apparatus is used for receiving the motor rotating signal and an original G/L switching point signal and utilizing the motor rotating signal and the original G/L switching point signal to determine a location of an reproduced G/L switching point of the optical disc. The G/L switching point generating apparatus is for generating an reproduced G/L switching point signal according to the location of the reproduced G/L switching point determined by the detection apparatus.Type: GrantFiled: January 26, 2006Date of Patent: March 8, 2011Assignee: MediaTek Inc.Inventors: Chang-Long Wu, Meng-Hsueh Lin, Ming-Jiou Yu
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Publication number: 20100128586Abstract: An apparatus for accessing data from a disc with a linking area comprises a pick up head, a servo, a processing unit, a position predictor, and a control signal generator. The pick up head reads data from the disc and generates a read signal. The servo controls the pick up head. The processing unit processes the read signal and controls the servo according to a plurality of control signals. The position predictor tracks time position on the disc and generates position information. The control signal generator receives the position information and generates the control signals according to the position information.Type: ApplicationFiled: November 25, 2008Publication date: May 27, 2010Applicant: MEDIATEK INC.Inventors: Chang-Long Wu, Shu-Hung Chou
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Publication number: 20090323507Abstract: The present invention discloses an apparatus for converting a groove/land polarity on an optical medium, which comprises a physical identification (PID) detector detecting a first sector into a first PID value, a sector information unit providing an information including a second PID value indicative of either a second sector or at least one reference groove/land changing point, a sector counter counting a first value whose an initiation is set by the sector information unit based on the information and/or the PID detector based on the first PID value, and a comparing unit determining at least one oncoming groove/land changing points, based on when the first value approaches a second value either predetermined in or generated by the sector information unit according to said information.Type: ApplicationFiled: July 29, 2009Publication date: December 31, 2009Applicant: MEDIATEK Inc.Inventors: Meng-hsueh Lin, Chang-long Wu
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Patent number: 7355939Abstract: A system and method of switching the control modes of spindle motor are described. The switch system comprises a first control module, a second control module and a switch controller. The first control module electrically coupled to the spindle motor and the OPU controls the spindle motor to be operated in a present mode. The second control module is electrically coupled to the spindle motor to control the spindle motor to be operated in the transition mode between the present mode and the target mode. The switch controller electrically coupled to the first control module, the second control module and the spindle motor receives a present feedback signal associated with the rotation of spindle motor to generate a first switch signal. Furthermore, the switch controller receives a target indicative signal associated with the information on the optical storage medium to generate a second switch signal.Type: GrantFiled: August 11, 2006Date of Patent: April 8, 2008Assignee: MEDIATEK Inc.Inventors: Chang-long Wu, Chao-long Tsai
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Publication number: 20080037961Abstract: A system and method of switching the control modes of spindle motor are described. The switch system comprises a first control module, a second control module and a switch controller. The first control module electrically coupled to the spindle motor and the OPU controls the spindle motor to be operated in a present mode. The second control module is electrically coupled to the spindle motor to control the spindle motor to be operated in the transition mode between the present mode and the target mode. The switch controller electrically coupled to the first control module, the second control module and the spindle motor receives a present feedback signal associated with the rotation of spindle motor to generate a first switch signal. Furthermore, the switch controller receives a target indicative signal associated with the information on the optical storage medium to generate a second switch signal.Type: ApplicationFiled: August 11, 2006Publication date: February 14, 2008Applicant: Media Tek Inc.Inventors: Chang-long Wu, Chao-Iong Tsai
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Patent number: 7304926Abstract: A motor control system comprises a motor controller and a clamp apparatus and is used for controlling a motor apparatus. The motor controller is used for generating a motor control output according to a reference signal and a feedback signal from the motor apparatus. The clamp apparatus is used for receiving the motor control output and has a clamp function for clamping the motor control output. The clamp apparatus determines whether the clamp function should be activated to clamp the motor control output within an acceptable clamp range according to at least one motor stability signal. When the motor stability signal indicates that the motor apparatus has been in a stable state, the clamp apparatus clamps the motor control output from the motor controller in the acceptable clamp range, so as to avoid an abnormal motor control output resulting from external sudden change.Type: GrantFiled: October 22, 2004Date of Patent: December 4, 2007Assignee: Mediatek Inc.Inventors: Chao-Lung Tsai, Chang-Long Wu
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Publication number: 20070171799Abstract: A system for determining groove/land (G/L) switching points of an optical disc is disclosed. The system includes a motor rotating signal generating apparatus, an detection apparatus, and a G/L switching point generating apparatus. The motor rotating signal generating apparatus is for sensing the rotation of a motor to generate a motor rotating signal with a period corresponding to the rotation of the optical disc. Also, the detection apparatus is used for receiving the motor rotating signal and an original G/L switching point signal and utilizing the motor rotating signal and the original G/L switching point signal to determine a location of an reproduced G/L switching point of the optical disc. The G/L switching point generating apparatus is for generating an reproduced G/L switching point signal according to the location of the reproduced G/L switching point determined by the detection apparatus.Type: ApplicationFiled: January 26, 2006Publication date: July 26, 2007Inventors: Chang-Long Wu, Meng-Hsueh Lin, Ming-Jiou Yu
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Patent number: 7138782Abstract: The present invention provides a motor control system and method thereof. The motor control system comprises a motor controller and a compensation device. The motor controller is used for generating a motor control output according to a reference signal and a first signal. The compensation device is used for generating a compensated motor control output according to the motor control output and a second signal. Moreover, the compensation device utilizes the compensated motor control output to reduce the steady-state phase error between the first signal and the reference signal.Type: GrantFiled: January 12, 2005Date of Patent: November 21, 2006Assignee: Mediatek, IncorporatedInventors: Chao-Lung Tsai, Chang-Long Wu
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Publication number: 20050206338Abstract: The present invention provides a motor control system and method thereof. The motor control system comprises a motor controller and a compensation device. The motor controller is used for generating a motor control output according to a reference signal and a first signal. The compensation device is used for generating a compensated motor control output according to the motor control output and a second signal. Moreover, the compensation device utilizes the compensated motor control output to reduce the steady-state phase error between the first signal and the reference signal.Type: ApplicationFiled: January 12, 2005Publication date: September 22, 2005Inventors: Chao-Lung Tsai, Chang-Long Wu
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Publication number: 20050135214Abstract: A motor control system comprises a motor controller and a clamp apparatus and is used for controlling a motor apparatus. The motor controller is used for generating a motor control output according to a reference signal and a feedback signal from the motor apparatus. The clamp apparatus is used for receiving the motor control output and has a clamp function for clamping the motor control output. The clamp apparatus determines whether the clamp function should be activated to clamp the motor control output within an acceptable clamp range according to at least one motor stability signal. When the motor stability signal indicates that the motor apparatus has been in a stable state, the clamp apparatus clamps the motor control output from the motor controller in the acceptable clamp range, so as to avoid an abnormal motor control output resulting from external sudden change.Type: ApplicationFiled: October 22, 2004Publication date: June 23, 2005Inventors: Chao-Lung Tsai, Chang-Long Wu