Unwanted Signal Component Indicating Patents (Class 369/53.33)
  • Patent number: 10771108
    Abstract: Embodiments relate to systems, methods, and computer-readable media to enable design and creation of crosstalk cancellation circuitry for a receiver (e.g. an AC coupled DDR5 receiver). One embodiment is a receiver apparatus with crosstalk victim and aggressors lines. The cancellation circuitry involves an amplifier and buffering circuitry to provide inductive and capacitive crosstalk cancellation voltages. Some embodiments can additionally involve circuitry for autozeroing modes for AC coupled receiver lines.
    Type: Grant
    Filed: December 17, 2019
    Date of Patent: September 8, 2020
    Assignee: Cadence Design Systems, Inc.
    Inventors: H Md Shuaeb Fazeel, Sachin Ramesh Gugwad
  • Patent number: 8947989
    Abstract: A wobble determining apparatus is provided with: a calculating device for calculating (i) a first time required until reaching a number of revolutions of a motor which allows a predetermined linear velocity, and (ii) a second time required to move an optical head to a position which allows the predetermined linear velocity, on the basis of the number of revolutions of the motor and the position of the optical head; a judging device for judging whether to keep the optical head in accordance with the calculated first time and the calculated second time; and a controlling device for controlling a moving device not to move the optical head if it is judged to keep the optical head, and for controlling the moving device to move the optical head to the position which allows the predetermined linear velocity if it is judged not to keep the optical head.
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: February 3, 2015
    Assignee: Pioneer Digital Design and Manufacturing Corporation
    Inventors: Takashi Tani, Yoshinori Kajiwara, Wataru Terui, Takahiro Otomo
  • Patent number: 8929186
    Abstract: A disk drive is disclosed comprising a head actuated over a disk, wherein the head comprises a laser operable to heat the disk while writing data to the disk. A laser power of the laser is initialized, and a test pattern is written to the disk. The test pattern is read from the disk to generate a read signal, and a quality metric and a track width of the test pattern is measured based on the read signal. The laser power is adjusted and the process is repeated until at least one of the quality metric substantially matches a target value and the track width substantially matches a track width threshold.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: January 6, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Abhimanyu Sharma, Poornima Nookala, Zhaobin Zhu
  • Publication number: 20140355404
    Abstract: An optical medium reproducing apparatus that optically reproduces an optical medium on which a plurality of tracks is formed in which a beam returning from the optical medium is divided into a first region of an outside portion and a second region of an inside region, according to the shape of the pupil of an object lens, and crosstalk between the tracks is reduced by using a first detection signal of the first region and a second detection signal of the second region.
    Type: Application
    Filed: May 15, 2014
    Publication date: December 4, 2014
    Applicant: Sony Corporation
    Inventors: Kenji YAMAMOTO, Takashi NAKAO, Kimihiro SAITO
  • Publication number: 20140160911
    Abstract: A method for evaluating a reproduction performance which reproduces a specific pattern recording signal to measure a reproduced signal noise, and calculates an evaluated value of a reproduction performance on the basis of a frequency characteristic of the measured reproduced signal noise.
    Type: Application
    Filed: December 9, 2013
    Publication date: June 12, 2014
    Inventors: Soichiro ETO, Yoshitaka MORIMOTO
  • Patent number: 8310905
    Abstract: A wobble signal extracting circuit includes: a readout signal generating circuit generating an RF signal by adding first and second detection signals corresponding to reflected light from inside and outside a recording track; a first subtractor generating a push-pull signal by subtracting the first and second detection signals, respectively; a first analog-to-digital converter (ADC) converting the RF signal to digital; a second ADC converting the push-pull signal to digital; a residual RF component generating circuit generating a residual RF signal component equivalent to the RF signal component remaining in the digitized push-pull signal; and a second subtractor generating the wobble signal by subtracting the residual RF signal component from the digitized push-pull signal. The residual RF component generating circuit generates the residual RF signal component so that it may approach the remaining RF signal component based on correlation between the wobble signal and the digitized RF signal.
    Type: Grant
    Filed: September 14, 2011
    Date of Patent: November 13, 2012
    Assignee: Renesas Electronics Corporation
    Inventor: Kinji Kayanuma
  • Patent number: 8218408
    Abstract: According to the present invention, when an apparatus performs reproduction from an optical disc of a format not compatible to the apparatus, the apparatus is prevented from obtaining an incorrect address and thus causing a malfunction. A recording method according to the present invention performs first conversion of bit-inverting m number (1?m<n; m an integer) of symbols at prescribed positions of a code word coded using an error correction code by a Reed-Solomon code and including symbol C(i) [i=0, 1, 2, . . . n; n is an integer] to generate conversion information; and records the conversion information on a first recording medium.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: July 10, 2012
    Assignee: Panasonic Corporation
    Inventors: Naohiro Kimura, Kohei Nakata, Toyoji Gushima, Hiroshi Ueda
  • Patent number: 8144560
    Abstract: The invention relates to a method for preventing interchange of a first optical information carrier (1) with a second optical information carrier in an optical drive. Initially, the light (5) is focused at the first optical information carrier (1) in the optical apparatus followed by the steps of detecting reflected light (8) from the first optical information carrier (1) and generating a plurality of signals (CA, RF, FE) from the detected light (8), such as a focus error signal (FE). Upon obtaining an indication of a signal, e.g. the focus error signal (FE), is absent or reduced below a certain level, there is a step of assessing if the first optical information carrier (1) has been removed from the optical drive. If removed, reproduction of information by the optical drive is made impossible until some pre-determined measures have been taken, e.g. restart of the optical drive or other measures.
    Type: Grant
    Filed: March 22, 2006
    Date of Patent: March 27, 2012
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Chee Kang Thong, Rain Zhang
  • Patent number: 8089841
    Abstract: Regarding a signal recorded with a first frequency in a recording area on a specific first recording layer and a signal recorded with a second frequency different from the first frequency in a recording area on a second recording layer which might cause interlayer crosstalk in relation to the first recording layer, a reproducing signal measurement method for a multilayer optical recording medium having at least three recording layers includes reproducing the signal recorded in the recording area on the first recording layer, separating signals recorded respectively with the first and second frequencies, discriminating signal amplitude of the first frequency and a maximum value in signal amplitude of the second frequency, and calculating a signal amplitude ratio between them to measure interlayer crosstalk contained in the signal reproduced from the recording area on the first recording layer. Thus, the interlayer crosstalk quantity caused by unnecessary light can be measured quantitatively.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: January 3, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Akemi Hirotsune, Junko Ushiyama, Hiroyuki Minemura, Takahiro Kurokawa, Harukazu Miyamoto
  • Patent number: 7978571
    Abstract: A recording apparatus (1) is provided with: a recording device (11) for recording a data pattern onto a recording medium (100); a first controlling device (22) for stopping the recording; a reading device (11) for reading the data pattern which is recorded immediately before the recording is stopped, thereby obtaining a read signal; a measuring device (19) for measuring jitter of the read signal; an adjusting device (21) for adjusting a recording condition such that the jitter satisfies a desired condition, and a second controlling device (22) for restarting the recording of the data pattern by using the adjusted recording condition.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: July 12, 2011
    Assignee: Pioneer Corporation
    Inventors: Shogo Miyanabe, Hiroyuki Uchino, Yoshio Sasaki
  • Patent number: 7936655
    Abstract: A read circuit of a disk drive system that adaptively reduces signal-dependent noise including a sequence detector, a signal-dependent adaptive engine and a signal-dependent post-processor. The sequence detector recovers a data sequence from equalized data. The signal-dependent adaptive engine generates signal-dependent coefficients, a mean value and a standard deviation of a signal-dependent error. The signal-dependent post-processor corrects the signal-dependent error.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: May 3, 2011
    Assignee: SAMSUNG Electronics Co., Ltd.
    Inventors: Ju-Hyung Hong, Il-Won Seo, Hyun-Wook Lim
  • Patent number: 7911899
    Abstract: An optical disc reproducing apparatus includes an analog-to-digital (A/D) converter which converts an analog signal obtained from an optical disc to a digital signal; an asymmetry compensator which detects and corrects an offset of the digital signal; a phase locked loop (PLL) which estimates a clock of the digital signal and compensates for a frequency error; a binary module which converts the digital signal to binary data; an equalizer which equalizes a particular frequency of the digital signal; and a channel identifier which detects a reference level of the binary module, based on an input signal of the equalizer.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: March 22, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jung Hyun Lee, Eun Jin Ryu, Eing Seob Cho, Jun Jin Kong
  • Patent number: 7872953
    Abstract: An apparatus generates outgoing data (OD) to be provided on an optical disk (1) in a burst cutting area (2). The burst cutting area (2) further comprises markings (3) which cause a marking frequency spectrum (MFS) when reading out the burst cutting area (2). The apparatus comprises a channel coder (4) which receives processed data (PD) and supplies the outgoing data (OD) having an outgoing data frequency spectrum (DFS) with suppressed DC-content. The apparatus further comprises a data processing device (5) which generates the processed data (PD) to obtain an outgoing frequency spectrum (DFS) wherein a frequency component causing interference with a low frequent component of the markings (3) is suppressed or not present.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: January 18, 2011
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Maarten Kuijper, Bart Van Rompaey, Jacobus Petrus Josephus Heemskerk, Cornelis Marinus Schep, Josephus Arnoldus Henricus Maria Kahlman
  • Patent number: 7872954
    Abstract: The invention provides for a method and apparatus for writing data to an optical disc and comprising recovering an output signal from optical reading head, scaling the said output signal responsive to secondary data derived from the disc by way of the optical reading head and deriving a Land Pre Pits (LPP) signal for use during recording to the disc from the said scaled output signal wherein the said scaling is arranged to increase the LPP signal when the LPP is identified as located adjacent a mark on the disc of low light reflectivity.
    Type: Grant
    Filed: June 6, 2005
    Date of Patent: January 18, 2011
    Assignee: NXP B.V.
    Inventors: Xinyan Wu, John A. Harold-Barry
  • Patent number: 7835242
    Abstract: A system controller of an optical disk recording and reproducing device makes a display portion display a precaution message for recommending a user to back up data recorded on the optical disk when it is determined that one or more values including a jitter value, a variation quantity of the jitter value, a block error rate and a block error rate at a particular position have exceeded precaution reference values. In addition, it makes a display portion display an urgent message for instructing a user to back up data recorded on the optical disk quickly when it is determined that one or more of the values have exceeded limit reference values.
    Type: Grant
    Filed: November 8, 2006
    Date of Patent: November 16, 2010
    Assignee: Funai Electric Co., Ltd.
    Inventor: Shuhei Nakayama
  • Patent number: 7804754
    Abstract: In three consecutive cells consisting of a preceding cell, a center cell, and a subsequent cell, a possible change rate of the amplitude of a reproduced signal for the center cell with respect to the sum of the multiple values of the preceding and subsequent cells is obtained in advance. Then, for reproduction, the sum of the multiple values of the adjacent preceding and subsequent cells is obtained with respect to each cell. The amplitude of the reproduced signal obtained at the center cell is corrected to be closer to a reference value on the basis of the obtained change rate and sum.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: September 28, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masakuni Yamamoto, Jun Sumioka, Kaoru Okamoto
  • Patent number: 7796482
    Abstract: The invention provides for a method, and related apparatus, of producing a Land Pre-Pit signal during playback of an optical disc and including the steps of obtaining an output signal from an optical detector and from which the Land Pre-Pit signal is to be derived, scaling the said output signal responsive to a determined amplitude of a high frequency crosstalk signal arising during reading of the disc and in a manner so as to increase the said output signal when the Land Pre-Pit identified as corresponding to a mark on the disc, and so as to decrease the output signal when the Land Pre-Pit is identified as corresponding to a space on the disc.
    Type: Grant
    Filed: June 6, 2005
    Date of Patent: September 14, 2010
    Assignee: NXP B.V.
    Inventors: Xinyan Wu, John A. Harold-Barry
  • Patent number: 7738333
    Abstract: An optical disk drive of recording a re-writable optical disk and the method thereof. First, an optimum power is determined. A gain of a SBAD (Sub Beam Adder) signal is adjusted for generating an calibrated SBAD signal such that the calibrated SBAD signal maintains at the same level during a write power phase and a read power phase substantially. Then, the re-writable optical disk is recorded by using the optimum power. Next, a defect of the re-writable optical disk is detected according to the calibrated SBAD signal. Then, the optical disk drive will jump over the defect and prevent it from being data-recorded so as to avoid system malfunction.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: June 15, 2010
    Inventors: Shih-Fang Chen, Chin-Yin Tsai
  • Patent number: 7652963
    Abstract: In a circuit for detecting a recorded area of an optical disk, when unnecessary noise is superimposed on the space portion of the digitized signal (RF) of an RF signal from the optical disk, a counter (20) for detecting a space portion detects the noise and resets a counter (81) for detecting a recorded area with an output signal S21 therefrom. This prevents the counter (81) for detecting a recorded area from erroneously outputting a recorded area detection signal (S12) due to the noise. As a result, a counter (80) for detecting an unrecorded area outputs an unrecorded area detection signal (S20) with high accuracy to bring a recorded area signal (RECD) from a flip-flop circuit (82) to the L level. Accordingly, an unrecorded area can be detected as it is inherently with high accuracy without being erroneously recognized as a portion in which a mark portion has been recorded.
    Type: Grant
    Filed: February 15, 2005
    Date of Patent: January 26, 2010
    Assignee: Panasonic Corporation
    Inventor: Kiyoshi Nakamori
  • Patent number: 7613086
    Abstract: A disk device includes: a rotating unit for rotating the optical disk; an optical pick-up for reading the information data recorded on the optical disk; a moving unit for moving the optical pick-up; a focus control unit for leading the focus of the optical pick-up; a tracking control unit for leading the tracking of the optical pick-up; and an adjusting unit for changing the setting value of an equalizer to adjust the equalizer, wherein: when the optical disk is loaded on the disk device, the optical pick-up is moved to the innermost periphery of the optical disk, the optical disk is rotated, the focus and the tracking are led, and the operation of the optical pick-up is raised; and the setting value of the equalizer is changed to adjust the equalizer at a position where the operation of the optical pick-up is raised.
    Type: Grant
    Filed: August 29, 2005
    Date of Patent: November 3, 2009
    Assignee: Funai Electric Co., Ltd.
    Inventor: Kazuto Kitagawa
  • Patent number: 7573798
    Abstract: A multi-level information reproducing method is provided which can increase the degree of separation between distributions of cell boundary values to thereby improve the accuracy of reproduction. Specifically, in a method of reproducing multi-level information recorded on a track of an optical information recording medium by virtually providing cells at equal intervals and by varying a width of an information pit in a track direction or an area of an information pit, a cell boundary value (a value obtained by sampling a reproduced signal when a center of a light spot is located at a boundary of cells) is corrected based on cell center values of two cells adjacent to the boundary (a value obtained by sampling a reproduced signal when the center of the light spot is located at a center of a cell), and the multi-level information is reproduced based on the corrected cell boundary value.
    Type: Grant
    Filed: May 18, 2006
    Date of Patent: August 11, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masakuni Yamamoto, Yasuyuki Miyaoka
  • Publication number: 20090040897
    Abstract: Regarding a signal recorded with a first frequency in a recording area on a specific first recording layer and a signal recorded with a second frequency different from the first frequency in a recording area on a second recording layer which might cause interlayer crosstalk in relation to the first recording layer, a reproducing signal measurement method for a multilayer optical recording medium having at least three recording layers includes reproducing the signal recorded in the recording area on the first recording layer, separating signals recorded respectively with the first and second frequencies, discriminating signal amplitude of the first frequency and a maximum value in signal amplitude of the second frequency, and calculating a signal amplitude ratio between them to measure interlayer crosstalk contained in the signal reproduced from the recording area on the first recording layer. Thus, the interlayer crosstalk quantity caused by unnecessary light can be measured quantitatively.
    Type: Application
    Filed: May 15, 2008
    Publication date: February 12, 2009
    Inventors: Akemi Hirotsune, Junko Ushiyama, Hiroyuki Minemura, Takahiro Kurokawa, Harukazu Miyamoto
  • Patent number: 7372791
    Abstract: The present invention is directed to a recording/reproducing apparatus having a Read After Write function which simultaneously performs recording operation and reproduction operation, and is such that, in a reproducing system (120) of a tape streamer (100) which performs Read After Write operation for signals through a magnetic tape (105), the apparatus serves to distribute reproduction signals obtained from the magnetic tape by a first data distribution switch (133) to store signals thus distributed into frame memories (135A), (135B) of 2 channels, and to distribute a recording signal from a recording system (110) by a second data distribution switch (134) as cause signals of crosstalk signals included in reproduction signals to store signals thus distributed into frame memories to generate pseudo crosstalk signals of respective channels by crosstalk cancellers (136A), (136B) on the basis of reproduction signals and cause signals of respective channels which are read out from the frame memories to cancel, ev
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: May 13, 2008
    Assignee: Sony Corporation
    Inventor: Hisato Hirasaka
  • Patent number: 7349304
    Abstract: An information storage medium according to an aspect of this invention has an information storage area for storing information, and a wobbled track which is used to guide a light beam on the information storage area, and is wobbled in correspondence with a frequency, a phase of which is modulated at predetermined timings to reflect predetermined information. The wobbled track is formed so that an evaluation result based on the frequency characteristics of a squared reproduction signal obtained by squaring a reproduction signal corresponding to the wobbled track, obtained from the reflected light of a light beam with which the wobbled track is irradiated, meets a predetermined evaluation measure.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: March 25, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihito Ogawa, Yuji Nagai
  • Patent number: 7349310
    Abstract: An optical disk drive of recording a re-writable optical disk and the method thereof. First, an optimum power is determined. A gain of a SBAD (Sub Beam Adder) signal is adjusted for generating an calibrated SBAD signal such that the calibrated SBAD signal maintains at the same level during a write power phase and a read power phase substantially. Then, the re-writable optical disk is recorded by using the optimum power. Next, a defect of the re-writable optical disk is detected according to the calibrated SBAD signal. Then, the optical disk drive will jump over the defect and prevent it from being data-recorded so as to avoid system malfunction.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: March 25, 2008
    Assignee: Tian Holdings LLC
    Inventors: Shih-Fang Chen, Chin-Yin Tsai
  • Patent number: 7342854
    Abstract: An apparatus for generating tracking error signals including: an optical detection unit having a plurality of divided light receiving elements to allow beams reflected from a recording surface of the optical disks to be incident; a comparator for outputting after comparing the signals from light receiving elements, which correspond to the set group of the optical detection unit, with the reference signals set for the each group; an error correction unit for correcting and outputting errors if there are any errors after mutual comparison with signals of the groups output from the comparator; a phase-difference detection unit for outputting the signals for each group that correspond to a phase-difference after mutual comparison of the signals of the groups output from the error correction unit; a subtractor for mutually subtracting the signals for each group from the phase-difference detection unit and outputting the tracking error signals.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: March 11, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dae-Hoon Kwon, Gae-ok Cho
  • Patent number: 7327658
    Abstract: The present invention is made to improve the conventional analog processing that is easily affected by variations in semiconductor processing. This invention provides a wobble signal processing apparatus that can reduce the circuit scale and the power consumption as well as improve the quality of signal processing. The wobble signal processing apparatus of the present invention digitally processes a part that has conventionally been processed by an analog system, and a PRML circuit is further provided to implement error detection, whereby the circuit scale and the power consumption is reduced. This improves the detection of a signal that is inputted to the wobble signal processing apparatus.
    Type: Grant
    Filed: November 28, 2003
    Date of Patent: February 5, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroki Mouri, Kouji Okamoto, Youichi Ogura
  • Patent number: 7307931
    Abstract: A method is described for setting an optimum recording power level for recording information on an optical record carrier. First a series of test patterns is written on the record carrier with a different recording power. On reading the test patterns, the jitter values of each read signal is determined. The jitter as a function of recording power is approximated with two linear functions. The optimum recording power level for the record carrier is derived from intersection of the functions. The invention relates also to a device arranged to perform the method. The invention further relates to an optical record carrier comprising the optimum recording power as determined by the method according to the invention.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: December 11, 2007
    Inventor: Sorin G. Stan
  • Patent number: 7304923
    Abstract: A push pull signal is detected from a disk-shaped storage medium on which wobbling grooves are formed as recording tracks and address information is recorded by forming pre-pits on lands between adjacent grooves. The detected push-pull signal is compared with a reference voltage thereby generating a land pre-pit detection signal. Of pulses included in the land pre-pit detection signal, those pulses having a small pulse width are regarded as noise pulses and removed thereby obtaining a corrected land pre-pit detection signal. The number of pulses included in the land pre-pit detection signal is counted, and the reference voltage is controlled in accordance with the counted number of pulses.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: December 4, 2007
    Assignee: Sony Corporation
    Inventors: Tatsushi Sano, Mitsuyuki Bamba, Toshimasa Miyoshi
  • Patent number: 7269113
    Abstract: A device for recording and/or reading a record carrier has an optical head with a laser for generating a beam via a scanning spot on a track of the carrier. A detector detects a read signal and a sensor detects a sense signal from the beam. A control unit controls the laser power to a desired value. A correction unit generates a correction signal that depends on local optical properties of the record carrier derived from the sense signal measured on at least one part of the track near the scanning spot. The device corrects the power control using the correction signal. Furthermore, the record carrier can have prerecorded control parameters for setting the correction unit.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: September 11, 2007
    Assignee: Koninklijke Phillips Electronics N.V.
    Inventor: Johannes Hendrikus Maria Spruit
  • Patent number: 7245572
    Abstract: A protecting device installed in an optical storage system for protecting a plurality of physical identification data synchronous signals includes a synchronous pattern detecting device, a data synchronous signal insertion device for adding the amount of data synchronous signals to a first predetermined number, a counting/reloading device for sequentially counting the first predetermined number of data synchronous signals and an additional second predetermined number of data synchronous signals, a PID window generator for generating a plurality of protecting windows respectively corresponding to the plurality of physical identification data synchronous signals while the counting/reloading device is counting the second predetermined number of data synchronous signals, and a PID synchronous signal protection device for protecting the plurality of physical identification data synchronous signals according to the plurality of protecting windows.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: July 17, 2007
    Assignee: Mediatek Incorporation
    Inventors: Jia-Hau Lin, Chi-Ming Chang
  • Patent number: 7218581
    Abstract: A device for delivering a data signal at a data rate has crosstalk cancellation. The crosstalk reducing unit (14) has an adaptive filter (15) to generate a crosstalk signal corresponding to a track adjacent to a track being scanned. A subtractor (16) subtracts the crosstalk signal from a read signal. A calculating unit (17) calculates filter coefficients for the adaptive filter. The adaptive filter (15) and subtractor (16) are coupled to an asynchronous clock (18) for operating at an asynchronous sample rate. The crosstalk reducing unit (14) has a sample rate converter (19) coupled to a synchronous clock for converting the output of the subtractor to the data signal (8) at a synchronous sample rate. A timing recovery unit (11) is coupled to the data signal (8) for retrieving the synchronous clock corresponding to the data rate.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: May 15, 2007
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Jo Stefan Frisson, David Modrie
  • Patent number: 7196991
    Abstract: An optical disk apparatus has an optical head having a lens of converging light from a light source onto an optical disk and a photodetector for detecting the light thus converged and then reflected from the optical disk. A tracking error signal is generated in order to perform tracking control on the basis of the detected light. A disk tilt DT is detected to indicate the amount of tilt of the optical head relative to the optical disk. A calculation is performed to calculate a lens shift LS indicating the amount of shift of the lens relative to the optical head, according to a predetermined rule on the basis of the generated tracking error signal and the detected disk tilt DT.
    Type: Grant
    Filed: November 26, 2001
    Date of Patent: March 27, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Junji Nagaoka, Seiji Nishiwaki, Kazuo Momoo
  • Patent number: 7193955
    Abstract: An optical head device includes: an optical element collecting light reflected from a reproduction information layer (a target information layer in an optical information recording medium) and light reflected from information layers adjacent to the reproduction information layer at different positions; a light receiving element obtaining a detection signal from the reflected light collected by this optical element; and arithmetic circuitry obtaining a reproduction signal from this detection signal.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: March 20, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuo Ito, Teruhiro Shiono, Seiji Nishino, Hiroaki Yamamoto
  • Patent number: 7177245
    Abstract: An apparatus for generating tracking error signals including: an optical detection unit having a plurality of divided light receiving elements to allow beams reflected from a recording surface of the optical disks to be incident; a comparator for outputting after comparing the signals from light receiving elements, which correspond to the set group of the optical detection unit, with the reference signals set for the each group; an error correction unit for correcting and outputting errors if there are any errors after mutual comparison with signals of the groups output from the comparator; a phase-difference detection unit for outputting the signals for each group that correspond to a phase-difference after mutual comparison of the signals of the groups output from the error correction unit; a subtractor for mutually subtracting the signals for each group from the phase-difference detection unit and outputting the tracking error signals.
    Type: Grant
    Filed: May 5, 2003
    Date of Patent: February 13, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dae-Hoon Kwon, Gae-ok Cho
  • Patent number: 7170845
    Abstract: An aberration correcting element includes a first aberration correction element movable along the optical axis of the light beam for correcting the aberration of the light beam; a driver for positioning the first aberration correction element along the optical axis in response to a drive control signal; a second aberration correction element having a plurality of phase adjustment portions each generating an amount of phase change in the light beam, the amount corresponding to an adjustment signal; a phase adjuster for supplying the adjustment signal to the respective adjustment portions in response to a phase control signal; a light receiver for receiving the light beam reflected from the recording medium to generate a light-receiving signal; and a controller for generating the drive control signal and the phase control signal based on the light-receiving signal.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: January 30, 2007
    Assignee: Pioneer Corporation
    Inventor: Masakazu Ogasawara
  • Patent number: 7126890
    Abstract: Techniques for reading data from a storage medium (150) having a high track density prone to adjacent track interference are disclosed. One or more sensing elements (120) are used to extract data stored on adjacent tracks. Multiuser detection (130) is then used to detect/decode a single track that is closely spaced to its neighboring tracks, resolve interference from adjacent tracks, or to simultaneously detect/decode multiple adjacent closely packed tracks.
    Type: Grant
    Filed: September 19, 2003
    Date of Patent: October 24, 2006
    Assignee: Bae Systems Information and Electronic Systems Integration INC
    Inventors: Rachel E. Learned, Robert B. MacLeod
  • Patent number: 7079457
    Abstract: A method of reproducing information by scanning information marks, disposed with a predetermined mark pitch therebetween and recorded on tracks inside a predetermined information recording region, by an optical spot. The method includes detecting the size of the optical change resulting from the information mark, calculating a plurality of equalization coefficients used for an equalization processing for the size of the optical change detected for each of the information marks, and reducing the inter-symbol interference on the basis of the equalization coefficients by the equalization processing. The equalization coefficient used for the equalization processing of the size of the optical change by a first information mark is greater than said equalization coefficient used for the equalization processing of the size of said optical change by a second information mark which is longer than the first information mark.
    Type: Grant
    Filed: November 19, 2003
    Date of Patent: July 18, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Kouichirou Wakabayashi, Hirofumi Sukeda
  • Patent number: 7057991
    Abstract: An apparatus and method detecting whether a signal read from an optical disc has a defect. The apparatus generates a defect signal of an optical disc and includes an average maximum value detecting unit, an average minimum value detecting unit, an instantaneous maximum value detecting unit, an instantaneous minimum value detecting unit, and a defect signal generating unit. The average maximum value detecting unit receives a predetermined RF signal for a predetermined period of time and calculates an average maximum value of maximum values of the RF signal. The average minimum value detecting unit receives the predetermined RF signal for a predetermined period of time and calculates an average minimum value of minimum values of the RF signal. The instantaneous maximum value detecting unit receives the RF signal and calculates an instantaneous maximum value that is a maximum value of the RF signal at an instant of time when the RF signal is input.
    Type: Grant
    Filed: May 27, 2003
    Date of Patent: June 6, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hyun-soo Park, Jao-seong Shim
  • Patent number: 7050371
    Abstract: A pick up irradiates light beams at specified intervals in the tangential direction of the main track to be reproduced and both of adjacent tracks on a disk 10 on which tracks are formed. A CTC unit 15 uses the delay amount ?d of the respective sample-value series corresponding to the reproduction signal RFm from the main track and reproduction signals RF1, RF2 from both adjacent tracks to correct the delay, then outputs a CTC output signal from which the cross-talk component has been removed. In addition, when adjusting the delay, the CPU 17 applies a disturbance to the control signal for the actuator of the servo-control unit 18 and changes the delay amount ?d within a specified range of change. At this time, the CPU 17 sets the delay amount ?d, which minimizes the jitter value found by the jitter detection unit 16 according to the CTC output signal, for the CTC unit 15. This makes it possible to set the optimum delay amount ?d when adjusting the delay, even when there is little steady cross-talk.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: May 23, 2006
    Assignee: Pioneer Corporation
    Inventors: Shogo Miyanabe, Hiroki Kuribayashi
  • Patent number: 7046595
    Abstract: A method of reproducing information by scanning information marks, disposed with a predetermined mark pitch therebetween and recorded on tracks inside a predetermined information recording region, by an optical spot. The method includes detecting the size of the optical change resulting from the information mark, calculating a plurality of equalization coefficients used for an equalization processing for the size of the optical change detected for each of the information marks, and reducing the inter-symbol interference on the basis of the equalization coefficients by the equalization processing. The equalization coefficient used for the equalization processing of the size of the optical change by a first information mark is greater than said equalization coefficient used for the equalization processing of the size of said optical change by a second information mark which is longer than the first information mark.
    Type: Grant
    Filed: November 19, 2003
    Date of Patent: May 16, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Kouichirou Wakabayashi, Hirofumi Sukeda
  • Patent number: 7023769
    Abstract: A data recording method for calculating a digital sum value (DSV) corresponding to a proportion of positive data and negative data included in predetermined data ranges, selecting a resync pattern to be inserted between the data ranges according to the DSV, and inserting the selected resync pattern between the data ranges, has a step of selecting a resync pattern that minimizes differences in DSV between the data ranges.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: April 4, 2006
    Assignee: Fujitsu Limited
    Inventors: Kenichi Hamada, Akira Nanba, Masakazu Taguchi
  • Patent number: 7009922
    Abstract: In a cross-talk canceller (CTC) that removes the cross-talk from the adjacent tracks that is contained in the reproduction signal from the main track, a sample-value series S1? for the reproduction signal from the adjacent track is input to a correlation-detection unit to find its correlation with the signal pattern of the signal output from the CTC that is detected by a pattern-detection unit, and then it passes through one of the correction-coefficient units that is connected by the switch and then integrated by the integrator, and the tap coefficient used by the variable filter of the CTC is obtained to a narrow control frequency zone.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: March 7, 2006
    Assignee: Pioneer Corporation
    Inventors: Shogo Miyanabe, Hiroki Kuribayashi
  • Patent number: 6992956
    Abstract: A disk reproducing apparatus includes a variable gain amplifier (VCA) (32), and the VCA applies a radial push-pull signal including an address signal and an FCM leakage-in signal to a switch (38). The switch outputs only the address signal to a peak-hold circuit (40) on the basis of an FCM mask signal from a mask signal generation circuit (36). The peak-hold circuit generates a peak-hold signal of the address signal so as to be output to a DSP (30), and the DSP controls a gain of the VCA on the basis of the peak-hold signal. Then, the radial push-pull signal in which the gain is controlled on the basis of the address signal is applied to an address detection circuit (42), and the address signal is detected therein.
    Type: Grant
    Filed: April 23, 2001
    Date of Patent: January 31, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Shigekazu Minechika, Koichi Tada, Junko Onaka, Takashi Onaka
  • Patent number: 6982937
    Abstract: Crosstalk cancellation is realized more accurately than ever by considering both magnitude and a phase difference of a crosstalk signal from a recording track adjoining a target track, in comparison with magnitude and a phase of a desired signal from the target track, which is implemented by providing a crosstalk amount detection means, a phase difference measurement means, and a crosstalk component generation means that generates a crosstalk component to be subtracted from a signal obtained by an optical scanning that includes the desired signal and the crosstalk.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: January 3, 2006
    Assignee: Fujitsu Limited
    Inventors: Toshikazu Kanaoka, Masakazu Taguchi, Akiyoshi Uchida
  • Patent number: 6970406
    Abstract: An information playback apparatus of the present invention is provided with: a first detecting unit for supplying a difference between respective output signals optically obtained by a pair of detectors for reading the information of the first track; a second detecting unit for supplying a difference between respective output signals optically obtained by a pair of detectors for reading the information of the second track adjacent to the first track; a first demodulating unit for demodulating a detected signal supplied from the first detecting unit, a second demodulating unit for demodulating a detected signal supplied from the second detecting unit. A coefficient controlling unit extracts the crosstalk caused by the second track, which is included in a demodulation signal obtained by the first demodulating unit, from the same signal and controls a coefficient based on the extracted crosstalk, and cancels the crosstalk by the calculated coefficient.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: November 29, 2005
    Assignees: Pioneer Corporation, Sony Corporation
    Inventors: Hiroki Kuribayashi, Takuma Yanagisawa, Hiroshi Ogawa
  • Patent number: 6947363
    Abstract: This invention provides a method of acquisition of binary information that has been stored physically in a periodic storage medium. The method, referred to as matrix-method deconvolution (MMD), is useful for use with optical storage media using an optical addressing system that reads and writes binary information in a periodic array of nano-particles. With this MMD method, the density of existing memory systems can be boosted to between 10 and 100 Terabytes of data per cubic centimeter. This matrix-method deconvolution method compensates for the effects of the optical addressing system's point spread function. Prior knowledge of a system's point spread function and inter memory-center spacing is used.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: September 20, 2005
    Inventors: Darren Kraemer, Bradley Siwick, R. J. Dwayne Miller
  • Patent number: 6944105
    Abstract: A method of reproducing information by scanning information marks, disposed with a predetermined mark pitch therebetween and recorded on tracks inside a predetermined information recording region, by an optical spot. The method includes detecting the size of the optical change resulting from the information mark, calculating a plurality of equalization coefficients used for an equalization processing for the size of the optical change detected for each of the information marks, and reducing the inter-symbol interference on the basis of the equalization coefficients by the equalization processing. The equalization coefficient used for the equalization processing of the size of the optical change by a first information mark is greater than said equalization coefficient used for the equalization processing of the size of said optical change by a second information mark which is longer than the first information mark.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: September 13, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Kouichirou Wakabayashi, Hirofumi Sukeda
  • Patent number: 6917574
    Abstract: User data is recorded in a recording medium while being linked in units of a fixed length packet, and information indicative of this fact is written to the recording medium. At the time of reading the user data, the position of data linking block can be detected by making reference to the identification information, whereby the excessive run-out blocks which would be otherwise requisite to detect the position of the data linking block are made unnecessary. At the time of data linking, a part where data in the run-in block is missing is filled with correct data, thus the run-in block can correctly be read, whereby the excessive run-in blocks which would otherwise be requisite are made unnecessary.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: July 12, 2005
    Assignee: Sony Corporation
    Inventor: Tetsuji Kawashima
  • Patent number: RE39306
    Abstract: An optical disc drive usable with discs to which data is continuously recorded and discs having a sector format can quickly resume playback signal output after passing imperfection causing potential reading errors, and plays disc with few read errors. A detection signal generator detects DC level fluctuation in the playback signal read from the disc and generates a detection signal tracking the DC level fluctuation. A selector selects a detection signal or a null signal without valid polarity based on the detection signal generated by the detection signal generator and input to the selector. A clamping unit performs a clamping process to suppress DC level fluctuation in the playback signal based on the detection signal when the selection unit selects the detection signal, and does not perform the clamping process when the selection unit selects the null signal. A signal processor performs specific signal processes based on clamping unit output.
    Type: Grant
    Filed: February 25, 2004
    Date of Patent: September 26, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shinichi Konishi, Takeshi Nakajima, Harumitsu Miyashita, Toshihiko Takahashi, Toshiya Akagi, Yuji Hisakado, Yukihiro Yamasaki