Binary Signal Level Detecting Using A Reference Signal Patents (Class 369/59.17)
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Patent number: 10925489Abstract: A medical system and method of communicating between a telemetry controller and medical devices is provided. Coupling coefficients between a primary coil of the telemetry controller and secondary coils of the medical devices differ from each other. A primary carrier signal is applied to the primary coil, thereby respectively inducing secondary carrier signals on the secondary coils. An amplitude of the secondary carrier signal is measured on each of the secondary coils. The envelope of each secondary carrier signal is modulated in accordance with data, thereby inducing modulation of the envelope of the primary carrier signal for the implanted medical devices. The secondary carrier signal envelopes are modulated based on the measured amplitudes of the respective secondary carrier signals.Type: GrantFiled: September 24, 2019Date of Patent: February 23, 2021Assignee: THE ALFRED E. MANN FOUNDATION FOR SCIENTIFIC RESEARCHInventors: Edward K. F. Lee, Harshit R. Suri
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Patent number: 9153270Abstract: A defect emulator module for a rotating storage device includes a coefficient module that generates a first coefficient. A location module generates a location. A defect signal module selectively modifies a read-back signal based on the first coefficient and the location. The first coefficient includes an emulation of a first defect in the read-back signal.Type: GrantFiled: August 24, 2007Date of Patent: October 6, 2015Assignee: Marvell International Ltd.Inventors: Zining Wu, Shaohua Yang
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Patent number: 8913472Abstract: A data capture device including a signal processing unit, a frequency locked circuit and a match circuit is provided. The signal processing unit converts a radio frequency signal to a return-to-zero signal. The frequency locked circuit estimates a minimum interval length by the return-to-zero signal in a plurality of detecting periods, and generates an enable signal according to the minimum interval length and the return-to-zero signal. The frequency locked circuit determines whether to calibrate the enable signal according to a distribution of a plurality of enable pulses in the enable signal to generate a sampling signal. The match circuit samples the return-to-zero signal by the sampling signal and generates a synchronization signal according to a sampling result. The match circuit generates a composite synchronization signal by a virtual signal and the synchronization signal, and captures a plurality of row data from the return-to-zero signal according to the composite synchronization signal.Type: GrantFiled: January 23, 2013Date of Patent: December 16, 2014Assignee: Sunplus Technology Co., Ltd.Inventors: Chang-Jin Song, Ping-Chiang Yang
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Patent number: 8804799Abstract: A signal quality measuring apparatus includes a binary signal generating unit to generate a binary signal from an input signal; a level information extracting unit to extract level information from a relationship between the input signal and the binary signal using at least two window lengths; and a quality calculating unit to calculate a quality of the input signal based on the level information.Type: GrantFiled: March 18, 2010Date of Patent: August 12, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Hyun-soo Park, Kyung-geun Lee, In-oh Hwang, Hui Zhao, Jong-hyun Shin
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Patent number: 8612029Abstract: A system includes at least one piece of equipment. The system also includes a state detector adapted to measure one or more operating parameters of the equipment. The system has a signature generator adapted to encode a plurality of data streams from the state detector into an operating signature for the equipment.Type: GrantFiled: June 16, 2008Date of Patent: December 17, 2013Assignee: Shell Oil CompanyInventors: Michael Edward Cottrell, Kenneth John Innes, James Po-Cheung Kong, Charles Anthony Lickteig, Robert Frank Parchewsky, Steven Michael Schultheis, Daniel Dazhang Ying
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Publication number: 20130235712Abstract: A data capture device including a signal processing unit, a frequency locked circuit and a match circuit is provided. The signal processing unit converts a radio frequency signal to a return-to-zero signal. The frequency locked circuit estimates a minimum interval length by the return-to-zero signal in a plurality of detecting periods, and generates an enable signal according to the minimum interval length and the return-to-zero signal. The frequency locked circuit determines whether to calibrate the enable signal according to a distribution of a plurality of enable pulses in the enable signal to generate a sampling signal. The match circuit samples the return-to-zero signal by the sampling signal and generates a synchronization signal according to a sampling result. The match circuit generates a composite synchronization signal by a virtual signal and the synchronization signal, and captures a plurality of row data from the return-to-zero signal according to the composite synchronization signal.Type: ApplicationFiled: January 23, 2013Publication date: September 12, 2013Applicant: Sunplus Technology Co., Ltd.Inventors: Chang-Jin Song, Ping-Chiang Yang
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Patent number: 8526289Abstract: An optical information reproducing apparatus includes: an irradiation section irradiating a light beam onto an optical information recording medium, in which holes are formed along a virtual track on a recording medium, along the virtual track; a light receiving section receiving a reflected light beam when the light beam is reflected by the optical information recording medium and sequentially generating a light receiving signal corresponding to the light intensity; a detection section detecting a variation pattern appearing when a signal level of the light receiving signal changes according to the hole; and a code string generating section, when generating a code string corresponding to the signal level, generating a code corresponding to the one hole from the variation pattern if the variation pattern falls within a range and generating a code string, which includes a plurality of codes, from the variation pattern if the variation pattern exceeds the range.Type: GrantFiled: June 10, 2010Date of Patent: September 3, 2013Assignee: Sony CorporationInventors: Goro Fujita, Daisuke Ueda, Mitsuaki Oyamada, Takashi Iwamura, Kimihiro Saito, Jingcheng Yuan
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Patent number: 8498186Abstract: The present disclosure relates to methods, software, and apparatuses for correcting reading and/or writing operations in an optical storage medium. The methods generally include reading a region of an optical storage medium to produce a readback signal, measuring timing offsets for a plurality of the data edges (including one or more non-guide edges), and storing an offset correction for at least one of the plurality of edges based on a measured offset of at least one of the plurality of edges relative to a predetermined offset. The disclosure advantageously enables precise measurement of timing offsets in optical storage media and correction of the measured offsets for timing offsets attributable to edge jitter, timing loop drift, or factors independent of variations in the medium and/or write operation characteristics.Type: GrantFiled: January 13, 2009Date of Patent: July 30, 2013Assignee: Marvell World Trade Ltd.Inventor: William R. Foland, Jr.
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Patent number: 8432780Abstract: An exemplary Viterbi decoding apparatus includes a Viterbi decoder and a level information generator. The Viterbi decoder is arranged for generating a first binary signal by decoding an input signal according to target level information. The level information generator is arranged to support a plurality of different hardware configurations each for level information generation, and operate in a target hardware configuration among the different hardware configurations to generate the target level information to the Viterbi decoder.Type: GrantFiled: May 10, 2012Date of Patent: April 30, 2013Assignee: Mediatek Inc.Inventors: Chih-Ching Yu, Chih-Chung Li
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Patent number: 8385173Abstract: A method of determining characteristics of a signal and an apparatus using the method. The apparatus for determining characteristics of a signal includes: a level detector receiving sample values of a radio frequency (RF) signal and binary data obtained by binarizing the RF signal, generating selection signals based on the binary data, classifying each of the sample values of the RF signal into one of a plurality of levels using the selection signals, and outputting average values of sample values of each level; and a signal characteristics determiner determining a characteristics value that indicates the characteristics of the RF signal using the average values of the sample values belonging to each level.Type: GrantFiled: June 25, 2010Date of Patent: February 26, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Hyun-soo Park, Jae-wook Lee, Jae-seong Shim, Jung-hyun Lee, Eing-seob Cho, Eun-jin Ryu
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Patent number: 8331208Abstract: An information readout device includes an equalizer and a maximum likelihood detector. The equalizer includes a second-order Volterra filter, and equalizes a readout signal read out from an information recording medium to a predetermined characteristic to output the equalization signal. The maximum likelihood detector outputs a binary signal through maximum likelihood detection based on the equalization signal. By limiting the number of second-order terms of the second-order Volterra filter to three terms or four terms, a nonlinear component can be effectively corrected.Type: GrantFiled: February 8, 2008Date of Patent: December 11, 2012Assignee: NEC CorporationInventor: Yutaka Yamanaka
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Patent number: 8264932Abstract: An optical disc device and an adjusting method for a recording condition for use with the optical disc device that records data into an optical disc medium by using codes whose shortest run length is 2T and reproduces the recorded data by using an adaptive equalizing procedure and a PRML procedure, wherein the recording condition is so adjusted that a reproduced signal with desired quality can be obtained, by using, as the adaptive equalizing procedure, a procedure in which a tap coefficient Cn is set to a value obtained by averaging values of a tap coefficient an renewed by a LMS method, located symmetrically with each other along the time axis.Type: GrantFiled: July 27, 2011Date of Patent: September 11, 2012Assignee: Hitachi Consumer Electronics Co., Ltd.Inventors: Hiroyuki Minemura, Takahiro Kurokawa
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Patent number: 8248903Abstract: An apparatus for improving decoding accuracy of an equalized signal having a direct current (DC) level obtained from an optical disk is provided. A Viterbi decoder is configured to decode the equalized signal and output a Viterbi-decoded signal. A DC controller is configured to adjust the DC level of the equalized signal such that the equalized signal with the adjusted DC level is decoded.Type: GrantFiled: April 21, 2010Date of Patent: August 21, 2012Assignee: Mediatek Inc.Inventors: Chih-Ching Yu, Yu-Hsuan Lin
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Patent number: 8243571Abstract: A reproduction signal evaluation method according to the present invention relates to adjustment of an edge portion between a shortest mark and a shortest space in a data sequence including marks and spaces in combination that is recordable on an information recording medium. In a pattern including a shortest mark and a shortest space adjacent before or after the shortest mark, a shift amount of an edge of the shortest mark is obtained from a differential metric calculated regarding one of a first pattern in which a space adjacent to the shortest mark and not adjacent to the shortest space is longer than the shortest space; and a second pattern in which a mark adjacent to the shortest space and not adjacent to the shortest mark is longer than the shortest mark.Type: GrantFiled: September 29, 2009Date of Patent: August 14, 2012Assignee: Panasonic CorporationInventors: Kiyotaka Ito, Yasumori Hino, Harumitsu Miyashita, Isao Kobayashi
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Patent number: 8218685Abstract: A system and method are provided for using disparity measurements to control the adjustment of a data slicer threshold. The method receives a serial stream of pseudorandom digital data signals having an average DC value, and compares data signal amplitudes to a slicer threshold value. In response to the slicer threshold value comparison, data signal “1” and “0” values are determined. A first sum of determined “1” values is created, and a second sum of determined “0” values is created. The slicer threshold value is adjusted in response to the comparison of the first and second sums. More explicitly, the slicer threshold value is adjusted to make “1” values more likely in response to the second sum being larger than the first sum. Alternately, the slicer threshold value is adjusted to make “0” values more likely in response to the second sum being smaller than the first sum.Type: GrantFiled: March 30, 2009Date of Patent: July 10, 2012Assignee: Applied Micro Circuits CorporationInventor: Sean Campeau
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Patent number: 8203922Abstract: A reproduction signal evaluation method according to the present invention relates to adjustment of an edge portion between a shortest mark and a shortest space in a data sequence including marks and spaces in combination that is recordable on an information recording medium. In a pattern including a shortest mark and a shortest space adjacent before or after the shortest mark, a shift amount of an edge of the shortest mark is obtained from a differential metric calculated regarding one of a first pattern in which a space adjacent to the shortest mark and not adjacent to the shortest space is longer than the shortest space; and a second pattern in which a mark adjacent to the shortest space and not adjacent to the shortest mark is longer than the shortest mark.Type: GrantFiled: September 29, 2009Date of Patent: June 19, 2012Assignee: Panasonic CorporationInventors: Kiyotaka Ito, Yasumori Hino, Harumitsu Miyashita, Isao Kobayashi
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Patent number: 8179760Abstract: A reproduction signal evaluation method according to the present invention relates to adjustment of an edge portion between a shortest mark and a shortest space in a data sequence including marks and spaces in combination that is recordable on an information recording medium. In a pattern including a shortest mark and a shortest space adjacent before or after the shortest mark, a shift amount of an edge of the shortest mark is obtained from a differential metric calculated regarding one of a first pattern in which a space adjacent to the shortest mark and not adjacent to the shortest space is longer than the shortest space; and a second pattern in which a mark adjacent to the shortest space and not adjacent to the shortest mark is longer than the shortest mark.Type: GrantFiled: October 5, 2009Date of Patent: May 15, 2012Assignee: Panasonic CorporationInventors: Kiyotaka Ito, Yasumori Hino, Harumitsu Miyashita, Isao Kobayashi
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Patent number: 8107341Abstract: An information reproducing apparatus (1) is provided with: a judging device (20) for judging whether or not a read signal (RRF) read from a recording medium (100) satisfies a desired reproduction property; a correcting device (18) for correcting waveform distortion occurring in a read signal corresponding to a long mark, of the read signal if it is judged that the read signal does not satisfy the desired reproduction property; and a waveform equalizing device (15) for performing a waveform equalization process on the read signal in which the waveform distortion is corrected.Type: GrantFiled: December 5, 2006Date of Patent: January 31, 2012Assignee: Pioneer CorporationInventors: Yoshio Sasaki, Shogo Miyanabe, Hiroyuki Uchino
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Patent number: 8094534Abstract: An information reproducing apparatus (1) is provided with: a waveform shaping device (14) for performing waveform shaping on a read signal (RRF) read from a recording medium (100), on the basis of a reference amplification factor; a correcting device (18) for correcting waveform distortion occurring in a read signal corresponding to at least a long mark, of the read signal on which the waveform shaping is performed; and a waveform equalizing device (15) for performing a waveform equalization process on the read signal in which the waveform distortion is corrected, the waveform shaping device arbitrarily increases the reference amplification factor.Type: GrantFiled: December 5, 2006Date of Patent: January 10, 2012Assignee: Pioneer CorporationInventors: Yoshio Sasaki, Shogo Miyanabe, Hiroyuki Uchino
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Patent number: 8059510Abstract: In an information reproducing device for performing maximum likelihood decoding using asynchronous sample data, data from the recording medium 101 is sampled by an A/D converter 103 at an asynchronous sampling clock generated by a clock generator 104, to obtain asynchronous sample data. A timing detector 106 detects a phase ? of the asynchronous sampling clock, where recording timings of data of the recording medium 101 are reference points. A reference value generator 108 generates reference values used in a Viterbi decoder 107, based on basic phase reference values at a phase of 0 and a phase signal ? of the asynchronous sampling clock. A basic reference value learner 109 learns and modifies the phase-0 basic reference values based on the phase signal ?, the asynchronous sample data, and the reference values.Type: GrantFiled: January 26, 2007Date of Patent: November 15, 2011Assignee: Panasonic CorporationInventor: Akira Yamamoto
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Patent number: 8059511Abstract: An information reproducing apparatus (1) is provided with: a correcting device (18) for correcting waveform distortion occurring in a read signal corresponding to a long mark, of a read signal (RRF) read from a recording medium (100); and a processing device (15) for performing a PRML (Partial Response Maximum Likelihood) process on the read signal in which the waveform distortion is corrected.Type: GrantFiled: December 5, 2006Date of Patent: November 15, 2011Assignee: Pioneer CorporationInventors: Yoshio Sasaki, Shogo Miyanabe, Hiroyuki Uchino
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Patent number: 8018811Abstract: A decoding apparatus includes a burst cutting area (BCA) signal interval measuring device which measures a signal interval of a BCA area and which outputs BCA signal interval information, a T converter which obtains T information from the BCA signal interval information, a sequencer which detects a space area based on a first threshold value and which outputs an output enable signal based on the T information and a detecting result, wherein the output enable signal shows that a signal is obtained from a data area of the BCA area, and the space area is a non-signal area of the BCA area, and a channel data converter which converts the T information into channel data based on the output enable signal from the sequencer.Type: GrantFiled: October 15, 2008Date of Patent: September 13, 2011Assignee: Renesas Electronics CorporationInventor: Takeo Ariyama
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Patent number: 7952974Abstract: An apparatus and method for measuring the quality of a signal on an optical disc based on level information of a viterbi decoder are provided. The signal quality measuring apparatus includes: a binary unit that generates binary signals from input RF signals; a channel identifier that receives the input RF signals and the binary signals output from the binary unit and outputs reference level values corresponding to the binary signals; and an information calculator that receives the reference level values and detects a signal quality value.Type: GrantFiled: July 9, 2010Date of Patent: May 31, 2011Assignee: Samung Electronics Co., Ltd.Inventors: Hyun-soo Park, Jae-seong Shim, Jae-wook Lee, Jung-hyun Lee, Eun-jin Ryu, Eing-seob Cho
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Patent number: 7929393Abstract: When recording recording information by forming on a recording medium a recording mark whose mark length is an integral multiple of the reference mark length according to a recording signal generated from a recording information signal, this method performs a process of: generating, after recording compensation recording information on the recording medium, a reproduction signal by reading out the compensation recording information; generating from the reproduction signal a reproduction clock whose cycle corresponds to the reference mark length; setting a signal level suitable for binarization determination of the reproduction signal as a distribution reference level, according to the difference in variation between white and black levels of the reproduction signal; and calculating the recording correction value for correcting the compensation recording signal, so that the reproduction signal becomes closer to the distribution reference level around a target cross timing determined based on the reproduction cType: GrantFiled: January 9, 2009Date of Patent: April 19, 2011Assignee: Sony CorporationInventor: Toshihiro Horigome
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Patent number: 7920445Abstract: An optical disc signal processing apparatus comprising: a binarizing circuit configured to compare a level of an RF (Radio Frequency) signal obtained by photoelectrically converting a reflected light of a laser beam applied to an optical disc and a level of a DC signal, to output a binarized signal for reproducing information recorded on the optical disc, a level of the DC signal being adjusted to a level at which jitter included in the binarized signal is minimized.Type: GrantFiled: July 18, 2007Date of Patent: April 5, 2011Assignees: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.Inventor: Hiroyuki Shiono
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Patent number: 7903521Abstract: An enhanced write splice for optical recording channels is disclosed. Optical control circuitry locks to previously-written data and determines the estimated write splice location. A training sequence is written to the optical medium at a location based on the estimated write splice location. The phase offset is then estimated by reading the training sequence. A new write splice location may then be calculated compensating for the phase offset estimate. Finally, the new data to be spliced may be written or overwritten to the channel at the new write splice location.Type: GrantFiled: August 3, 2010Date of Patent: March 8, 2011Assignee: Marvell World Trade Ltd.Inventors: Mats Oberg, Pantas Sutardja
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Patent number: 7898930Abstract: In an embodiment, an optical disk drive includes a land prepit detection circuit. With such circuit, if the optical disk drive reads a poor-quality disk on which, in terms of signals, LPP-like noises are caused by a defect of a land area, it is possible to increase the noise immunity and LPP detection accuracy of the optical disk drive so that the optical disk drive is capable of successfully detecting LPP without fail.Type: GrantFiled: March 31, 2008Date of Patent: March 1, 2011Assignee: Hitachi-LG Data Storage, Inc.Inventor: Jinya Ikeda
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Patent number: 7885160Abstract: There is provided an information recording and reproducing method and an apparatus for the same capable of optimizing the shift adjustment of a recording pulse recorded in an optical disk even at the time of recording information on the optical disk at a high speed. The shift adjustment value of the recording pulse optimized at a low speed recording on an optical disk is multiplied by a constant value to be taken as the optimum shift conditions of the recording pulse at the high speed recording.Type: GrantFiled: July 24, 2008Date of Patent: February 8, 2011Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.Inventors: Takakiyo Yasukawa, Koichi Watanabe, Naohito Ikeda, Toshio Shoji, Yasuhiro Wada
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Patent number: 7864647Abstract: A method and apparatus for calibrating the slice level of a pulse detector monitors the quality of the detected pulse signal to determine and optimize slice level. The method practiced may include two parts, including a coarse stage and a fine stage. The method practiced may further include a continuous adjustment mode of operation.Type: GrantFiled: August 9, 2005Date of Patent: January 4, 2011Assignee: Zoran CorporationInventors: Bassel Haddad, Andrew Popplewell
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Patent number: 7848200Abstract: A method of reproducing multilevel information using a light spot. The multilevel information is recorded by defining virtual cells at regular intervals on tracks of an optical information recording medium and varying sizes of information pits in the cells. The method includes the steps of obtaining cell boundary values, each of the cell boundary values being obtained by performing sampling when the center of the light spot reaches a boundary between adjacent cells, calculating cell boundary value metrics on the basis of the cell boundary values and prestored reference values for the cell boundary values, calculating path metrics on the basis of the cell boundary value metrics, selecting a path metric having a minimum value of the path metrics, and reproducing the multilevel information on the basis of the path metric having the minimum value of the path metrics.Type: GrantFiled: January 19, 2007Date of Patent: December 7, 2010Assignee: Canon Kabushiki KaishaInventors: Kaoru Okamoto, Jun Sumioka, Masakuni Yamamoto
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Patent number: 7839748Abstract: There is provided an optical information recording/reproducing apparatus capable of obtaining a high super-resolution effect using an optical information recording medium in which a super-resolution thin film is formed. An optical information recording medium 1 having a super-resolution layer is irradiated with a laser light in a light emission pattern such that a bias light emission portion that does not cause the super-resolution layer to be in the state of super-resolution and a pulse light emission portion that causes the super-resolution layer to be in the state of super-resolution alternatively appear, and reflected light is detected. A reproduction signal based on the pulse light emission portion and a reproduction signal based on the bias light emission portion are acquired.Type: GrantFiled: August 9, 2006Date of Patent: November 23, 2010Assignee: Hitachi, Ltd.Inventor: Takeshi Maeda
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Patent number: 7808874Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.Type: GrantFiled: March 8, 2010Date of Patent: October 5, 2010Assignee: Canon Kabushiki KaishaInventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
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Patent number: 7808873Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.Type: GrantFiled: March 8, 2010Date of Patent: October 5, 2010Assignee: Canon Kabushiki KaishaInventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
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Patent number: 7804755Abstract: A method of determining characteristics of a signal and an apparatus using the method. The apparatus for determining characteristics of a signal includes: a level detector receiving sample values of a radio frequency (RF) signal and binary data obtained by binarizing the RF signal, generating selection signals based on the binary data, classifying each of the sample values of the RF signal into one of a plurality of levels using the selection signals, and outputting average values of sample values of each level; and a signal characteristics determiner determining a characteristics value that indicates the characteristics of the RF signal using the average values of the sample values belonging to each level.Type: GrantFiled: November 3, 2004Date of Patent: September 28, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Hyun-soo Park, Jae-wook Lee, Jae-seong Shim, Jung-hyun Lee, Eing-seob Cho, Eun-jin Ryu
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Patent number: 7801005Abstract: An apparatus and method for measuring the quality of a signal on an optical disc based on level information of a viterbi decoder are provided. The signal quality measuring apparatus includes: a binary unit that generates binary signals from input RF signals; a channel identifier that receives the input RF signals and the binary signals output from the binary unit and outputs reference level values corresponding to the binary signals; and an information calculator that receives the reference level values and detects a signal quality value.Type: GrantFiled: September 1, 2004Date of Patent: September 21, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Hyun-soo Park, Jae-seong Shim, Jae-wook Lee, Jung-hyun Lee, Eun-jin Ryu, Eing-seob Cho
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Patent number: 7787345Abstract: An optical read/write apparatus causes a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers. In this case, the optical read/write apparatus operates so that data is read/written from/into a second data storage layer after fully recording a recordable area of a first data storage layer. Thus, light can be shone with uniform intensity across the substantially entire recordable area of the second data storage layer without using a complex read/write system even under such conditions that the transmittance to light of the first data storage layer in the recordable area may vary depending on whether any data is recorded in the recordable area.Type: GrantFiled: February 6, 2007Date of Patent: August 31, 2010Assignee: Sharp Kabushiki KaishaInventors: Junji Hirokane, Noboru Iwata
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Patent number: 7787335Abstract: An information recording device, an information recording method, and an information recording program capable of recording information with an appropriate modulation degree, a high asymmetry, and small waveform distortion. The information recording device applies a laser beam to a recording medium such as a DVD-R/RW and DVD+R/RW and forms a recording mark corresponding to a recording signal, thereby recording information. A recording pulse signal for forming the recording mark corresponding to the recording signal has a mark period for forming the recording mark and a space period not forming the recording mark. In test recording performed prior to actual information recording, a long mark recording power is kept constant while a short mark recording power is changed. Preferably, the short mark recording power in the test write is changed so that the asymmetry and/or the beta value is a value within a desired range.Type: GrantFiled: March 30, 2005Date of Patent: August 31, 2010Assignee: Pioneer CorporationInventors: Yoshio Sasaki, Hiroyuki Uchino, Kunihiko Horikawa
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Patent number: 7751295Abstract: Quantization noise due to analog-to-digital conversion may be larger than a noise component of an input signal, and therefore sufficient performance may not be obtained.Type: GrantFiled: May 10, 2006Date of Patent: July 6, 2010Assignees: Hitachi, Ltd., Hitachi LG Data Storage, Inc.Inventor: Manabu Katsuki
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Patent number: 7738338Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings. The multivalued information is recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot. The multivalued information is reproduced by detecting the level of a multistage reproduced signal from the information pit. The method includes sampling a reproduced signal in the multivalued information recorded in one cell with an M-value (M<N), which is arranged at each of the plurality of cells recorded with an N-value (N?3) on the track, and detecting a cell center value.Type: GrantFiled: June 19, 2007Date of Patent: June 15, 2010Assignee: Canon Kabushiki KaishaInventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
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Publication number: 20100097910Abstract: An information readout device includes an equalizer and a maximum likelihood detector. The equalizer includes a second-order Volterra filter, and equalizes a readout signal read out from an information recording medium to a predetermined characteristic to output the equalization signal. The maximum likelihood detector outputs a binary signal through maximum likelihood detection based on the equalization signal. By limiting the number of second-order terms of the second-order Volterra filter to three terms or four terms, a nonlinear component can be effectively corrected.Type: ApplicationFiled: February 8, 2008Publication date: April 22, 2010Applicant: NEC CORPORATIONInventor: Yutaka Yamanaka
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Patent number: 7660224Abstract: A loss of performance of slicer adaptation at high capacities due to the mismatch between the exact bits used in the computation of the RDS for the DC-control on the one hand and the often erroneous threshold decisions that are preliminarily made based on the HF waveform on the other hand, is resolved by performing a new method of DC-control at the encoder: the RDS is modified such that it is not based on the exact channel bits, but on the threshold decisions from a synthetic HF signal waveform that is generated based on a nominal MTF (modulation transfer function) or its IRF (impulse response function) of the channel. In this way, the impact of the erroneous threshold decisions in the receiver are already taken into account at the encoder, and the slicer control is no longer negatively affected thereby.Type: GrantFiled: April 8, 2005Date of Patent: February 9, 2010Assignee: Koninklijke Philips Electronics N.V.Inventors: Willem Marie Julia Marcel Coene, Bin Yin
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Publication number: 20090316557Abstract: An information reproducing apparatus (1) is provided with: an amplitude limiting device (151, 152) for obtaining an amplitude limit signal (RSLIM) by limiting an amplitude level of a read signal (RRF) read from a recording medium (100) on the basis of a predetermined amplitude limit value (L); a filtering device (153) for obtaining an equalization-corrected signal by performing a high-frequency emphasizing and filtering process on the amplitude limit signal; and an adjusting device (18) for variably adjusting a reference level which indicates a reference point of the amplitude level on the amplitude limiting device.Type: ApplicationFiled: October 31, 2006Publication date: December 24, 2009Inventors: Yoshio Sasaki, Shogo Miyanabe, Hiroyuki Uchino
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Patent number: 7541955Abstract: An A/D conversion circuit converts an asymmetric analogue signal into a digital signal. In an A/D conversion circuit of a parallel type, a central value of a reference voltage is adjusted by means of an average of an input analogue signal, such as a reproduced RF signal from an optical disk, or the like. The average value of the input analogue signal is detected by means of a low-pass filter (LPF). Respective comparators compare the input analogue signal with the reference voltage, and encodes a result of comparison by means of an encoder. An A/D conversion characteristic determined by voltage values from a maximum value Vref1 to an average value and another A/D conversion characteristic determined by voltage values from the average value to a minimum value Vref2 become nonlinear, thereby becoming able to address asymmetry of the input analogue signal.Type: GrantFiled: September 21, 2007Date of Patent: June 2, 2009Assignee: TEAC CorporationInventor: Keishi Ueno
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Patent number: 7542394Abstract: The invention provides a method effective in detecting a reproduction signal in real time correction in which correction is simultaneously performed with recording. In this method, a laser beam emitted from a laser diode 110 is divided into a plurality of beam spots by a diffraction grating 114. One of the plurality of beam spots is used as a beam spot for recording, and another beam spot is used as a beam spot for reproduction. Reflected light components obtained from these beam spots are independently detected by a detector 122. A period for which a recording laser beam is in an ON state is referred to as a gate signal, and a mask is put on an RF signal obtained from a beam spot for reproduction, thereby selectively detecting pits reproduced when the recording laser beam is in the ON state.Type: GrantFiled: September 9, 2005Date of Patent: June 2, 2009Assignee: Taiyo Yuden Co., Ltd.Inventors: Yoshikazu Sato, Mitsuo Sekiguchi, Hiroya Kakimoto, Fuyuki Miyazawa, Tetsuharu Kubo
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Publication number: 20090116357Abstract: In a reproducing apparatus, a reading unit reads an information signal from a storage medium, and a converter converts the information signal reproduced by the reading unit into a first digital signal by sampling the information signal in accordance with a reference clock signal with a predetermined frequency higher than the frequency of the information signal. An oversampling unit generates a second digital signal by increasing the number of samples of the first digital signal output from the converter. A data detector selects two adjacent samples from the second digital signal on the basis of the frequency of the information signal reproduced by the reading unit and a phase change of the information signal. The data detector then generates read data using the selected samples of the digital signal.Type: ApplicationFiled: October 31, 2008Publication date: May 7, 2009Applicant: CANON KABUSHIKI KAISHAInventor: Yasuyuki Tanaka
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Publication number: 20090103412Abstract: A recording control apparatus includes a waveform rectification section for receiving a digital signal generated from an analog signal representing information reproduced from an information recording medium, and rectifying a waveform of the digital signal; a maximum likelihood decoding section for performing maximum likelihood decoding of the digital signal having the waveform thereof rectified, and generating a binary signal representing a result of the maximum likelihood decoding; a reliability calculation section for calculating a reliability of the result of the maximum likelihood decoding based on the digital signal having the waveform thereof rectified and the binary signal; and an adjusting section for adjusting a shape of a recording signal for recording the information on the information recording medium based on the calculated reliability.Type: ApplicationFiled: October 13, 2008Publication date: April 23, 2009Inventors: Harumitsu MIYASHITA, Takeshi Nakajima, Naohiro Kimura
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Patent number: 7522492Abstract: An ADIP (address in pre-groove) signal detection circuit is capable of correctly and quickly detecting discontinuous points in a wobble signal, and has a simple configuration in a wobble detection system of an optical disc device such as a DVD+R/RW, and an ADIP signal detection method thereof. The ADIP signal detection circuit performing the ADIP signal detection method includes one or two window comparators, two edge detection circuits each consisting of an exclusive OR circuit and an AND circuit, and two discontinuous point determination circuits each consisting of a flip-flop and a counter. Therefore, the ADIP signal detection circuit has a simple configuration so that it can be easily implemented. Also, since the ADIP signal detection circuit has a fast operation speed, the ADIP signal detection circuit detects discontinuous points correctly and quickly.Type: GrantFiled: August 9, 2007Date of Patent: April 21, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Soo-yong Kim, Young-hoon Lee, Seok-min Yun
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Patent number: 7515654Abstract: A data slicing circuit that receives a demodulated signal including a known data pattern followed by unknown data generates at least two different threshold potentials intermediate between the peak and bottom levels of the demodulated signal. Different comparators compare the demodulated signal with the different threshold potentials to generate at least two different binarized signals. During reception of the known data pattern, a signal processing circuit compares the binarized signals with the known data pattern, preferably oversampling the binarized signals, and selects the binarized signal that best matches the known data. The selected binarized signal is then used to receive the unknown data.Type: GrantFiled: August 31, 2005Date of Patent: April 7, 2009Assignee: Oki Semiconductor Co., Ltd.Inventor: Masato Umetani
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Publication number: 20090073840Abstract: According to one aspect of the present invention, there is provided an optical disk drive that is equipped with a land prepit detection circuit, the land prepit detection circuit including: a first peak hold circuit for inputting a push-pull signal to output a first peak voltage; a second peak hold circuit for inputting the push-pull signal through an LPF to output a second peak voltage; a bottom hold circuit for inputting the first peak voltage to output a bottom voltage; a slice level generation circuit for dividing the difference between the bottom voltage and the second peak voltage to generate a slice level used to detect a land prepit; and a comparator for comparing the push-pull signal with the slice level generated by the slice level generation circuit to detect the land prepit.Type: ApplicationFiled: March 31, 2008Publication date: March 19, 2009Applicant: Hitachi-LG Data Storage, Inc.Inventor: Jinya Ikeda
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Patent number: RE40822Abstract: A calibration method for a slice level of zero cross signal and a method of producing zero cross signal are disclosed. In this invention, the positive cycle and the negative cycle of the zero cross signal are sampled to obtain an error value related to the slice level due to asymmetry of the zero cross signal. By this invention, the asymmetry between the positive cycle and the negative cycle of the zero cross signal can be adjusted.Type: GrantFiled: August 23, 2007Date of Patent: July 7, 2009Inventor: Ronnie Lai