Patents by Inventor Manabu Shiozawa
Manabu Shiozawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Publication number: 20130301398Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.Type: ApplicationFiled: July 17, 2013Publication date: November 14, 2013Inventors: Shinji FUJITA, Takeshi MAEDA, Manabu SHIOZAWA, Takahiro KUROKAWA
-
Patent number: 8514683Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.Type: GrantFiled: April 17, 2012Date of Patent: August 20, 2013Assignee: Hitachi Consumer Electronics Co., Ltd.Inventors: Shinji Fujita, Takeshi Maeda, Manabu Shiozawa, Takahiro Kurokawa
-
Patent number: 8358569Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.Type: GrantFiled: May 2, 2011Date of Patent: January 22, 2013Assignee: Hitachi, Ltd.Inventors: Shinji Fujita, Takeshi Maeda, Manabu Shiozawa, Takahiro Kurokawa
-
Patent number: 8335140Abstract: The present invention provides a multilayer optical disc and an optical disc drive which can identify recording layers without performing tracking servo control or changing the structure of the disc. In a multilayer optical disc 100, the recording layer includes a layer identification region 101 having a recording pattern for layer identification, the layer identification region 101 including a layer specific region 102 having a specific pattern and a common region 103 having a common pattern different from the specific pattern, the layer specific region 102 being provided at a different radial position in each of the recording layers. The optical disc drive detects the layer specific region 102 having the specific pattern from the layer identification region 101 of the multilayer optical disc 100, and identifies the current layer based on the radial position of the layer specific region.Type: GrantFiled: July 11, 2011Date of Patent: December 18, 2012Assignees: Hitachi-LG Data Storage, Inc., Hitachi Consumer Electronics Co., Ltd.Inventors: Manabu Shiozawa, Takakiyo Yasukawa
-
Patent number: 8279732Abstract: An HF waveform prevailing during a read operation varies due, for instance, to changes in the ambient temperature of an optical disc drive and variations in the characteristics of a laser. This degrades read performance and decreases the number of rewritable disc read operations. To address the above problems, an optical disc drive and an optical information read method are disclosed. The disclosed optical disc drive and optical information read method vary an HF amplitude in relation to the resistance, differential resistance, or temperature of the laser.Type: GrantFiled: December 17, 2009Date of Patent: October 2, 2012Assignees: Hitachi-LG Data Storage, Inc., Hitachi Consumer Electronics Co., Ltd.Inventors: Koichi Watanabe, Manabu Shiozawa
-
Patent number: 8243568Abstract: An optical disc apparatus for recording or reproducing on or from an optical disc, comprising a laser light source for emitting a laser beam; a drive portion for driving the laser light source; a detection portion for detecting the emission power of the laser beam; and means for focusing the laser beam onto the optical disc, wherein information is reproduced by a reproducing power varied according to a recording power to obtain reproducing signals having necessary quality while suppressing deterioration of the recording quality due to the reproducing power.Type: GrantFiled: November 19, 2009Date of Patent: August 14, 2012Assignee: Hitachi-LG Data Storage, Inc.Inventor: Manabu Shiozawa
-
Publication number: 20120201113Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.Type: ApplicationFiled: April 17, 2012Publication date: August 9, 2012Applicant: Hitachi, Ltd.Inventors: Shinji FUJITA, Takeshi MAEDA, Manabu SHIOZAWA, Takahiro KUROKAWA
-
Patent number: 8228780Abstract: Proposed is an optical disk device capable of optimally adjusting a current value of a direct current and a high frequency superimposed current for driving a laser diode. This optical disk device includes a laser driver for superimposing a high frequency current on a direct current to obtain a drive current and supplying the drive current to the laser beam source and driving the laser beam source, and a control unit for adjusting a current value of the direct current and/or the high frequency superimposed current supplied by the laser driver to the laser beam source based on the servo signal or the reproduction signal.Type: GrantFiled: November 5, 2010Date of Patent: July 24, 2012Assignees: Hitachi-LG Data Storage, Inc., Hitachi Consumer Electronics Co., Ltd.Inventor: Manabu Shiozawa
-
Patent number: 8203919Abstract: The invention provides an optical disc apparatus which prevents that a laser beam whose power is set at a read power level causes erroneous data recording or deletion. The optical disc apparatus includes an emission controller which controls an amount of an electrical current that a current supply portion supplies to a laser diode in order to control a level of emission power at which the laser diode emits the laser beam. The emission controller has a function to set levels of the emission power at the following transition processings: a transition processing after a read processing and before a write processing, a transition processing after a write processing and before a read processing, a transition processing between two read processings for respective areas, and a transition processing between two write processings for respective areas.Type: GrantFiled: December 17, 2010Date of Patent: June 19, 2012Assignees: Hitachi-LG Data Storage, Inc., Hitachi Consumer Electronics Co., Ltd.Inventors: Shinsuke Izawa, Manabu Shiozawa
-
Patent number: 8194523Abstract: An optical disc apparatus includes a light source for emitting laser light, a light source drive unit for driving said light source, an optical element for splitting the laser light into a plurality of light fluxes, an optical element drive unit for controlling the optical element, an element for focusing the laser light onto the optical disc, and a detection unit for detecting the laser light reflected by the optical disc. Reproduction of the optical disc is performed by switching effectiveness and ineffectiveness of a function of splitting the light flux of the optical element, and adjustment of an outgoing laser power is performed.Type: GrantFiled: May 24, 2010Date of Patent: June 5, 2012Assignee: Hitachi-LG Data Storage, Inc.Inventor: Manabu Shiozawa
-
Publication number: 20120033535Abstract: The present invention provides a multilayer optical disc and an optical disc drive which can identify recording layers without performing tracking servo control or changing the structure of the disc. In a multilayer optical disc 100, the recording layer includes a layer identification region 101 having a recording pattern for layer identification, the layer identification region 101 including a layer specific region 102 having a specific pattern and a common region 103 having a common pattern different from the specific pattern, the layer specific region 102 being provided at a different radial position in each of the recording layers. The optical disc drive detects the layer specific region 102 having the specific pattern from the layer identification region 101 of the multilayer optical disc 100, and identifies the current layer based on the radial position of the layer specific region.Type: ApplicationFiled: July 11, 2011Publication date: February 9, 2012Inventors: Manabu SHIOZAWA, Takakiyo Yasukawa
-
Publication number: 20110211432Abstract: The invention provides an optical disc apparatus which prevents that a laser beam whose power is set at a read power level causes erroneous data recording or deletion. The optical disc apparatus includes an emission controller which controls an amount of an electrical current that a current supply portion supplies to a laser diode in order to control a level of emission power at which the laser diode emits the laser beam. The emission controller has a function to set levels of the emission power at the following transition processings: a transition processing after a read processing and before a write processing, a transition processing after a write processing and before a read processing, a transition processing between two read processings for respective areas, and a transition processing between two write processings for respective areas.Type: ApplicationFiled: December 17, 2010Publication date: September 1, 2011Inventors: Shinsuke IZAWA, Manabu Shiozawa
-
Publication number: 20110209166Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.Type: ApplicationFiled: May 2, 2011Publication date: August 25, 2011Applicant: Hitachi, Ltd.Inventors: Shinji FUJITA, Takeshi MAEDA, Manabu SHIOZAWA, Takahiro KUROKAWA
-
Patent number: 8000211Abstract: An optical disc apparatus capable of obtaining an effect to reduce the laser noise without shortening the laser diode service life or increasing the power consumption. The optical disc apparatus includes a laser diode for emitting a laser beam, a laser driver for driving the laser diode, a detector for monitoring a first power emitted from the laser diode, a detector for monitoring a second power applied to an optical disc, and an attenuator for attenuating the first power. The light attenuation factor of the attenuator is changed by the ratio between the first power and the second power.Type: GrantFiled: March 14, 2008Date of Patent: August 16, 2011Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.Inventor: Manabu Shiozawa
-
Patent number: 7965590Abstract: An optical disc apparatus includes a laser diode for emitting a laser light, a beam splitter for dividing the laser light into a main beam and sub beam, a main photodetector for detecting the main beam to output a main push-pull signal, a sub photodetector for detecting the sub beam to output a sub push-pull signal, and a subtracter for calculating the main and sub push-pull signals to output a differential push-pull signal, in which an amplification degree of the sub push-pull signal is adjusted so that a DC offset on the differential push-pull signal is adjusted, even in the case where a laser intensity is varied.Type: GrantFiled: March 28, 2008Date of Patent: June 21, 2011Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.Inventors: Manabu Shiozawa, Takahiro Kurokawa
-
Patent number: 7961580Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.Type: GrantFiled: December 22, 2008Date of Patent: June 14, 2011Assignee: Hitachi, Ltd.Inventors: Shinji Fujita, Takeshi Maeda, Manabu Shiozawa, Takahiro Kurokawa
-
Publication number: 20110110206Abstract: Proposed is an optical disk device capable of optimally adjusting a current value of a direct current and a high frequency superimposed current for driving a laser diode. This optical disk device includes a laser driver for superimposing a high frequency current on a direct current to obtain a drive current and supplying the drive current to the laser beam source and driving the laser beam source, and a control unit for adjusting a current value of the direct current and/or the high frequency superimposed current supplied by the laser driver to the laser beam source based on the servo signal or the reproduction signal.Type: ApplicationFiled: November 5, 2010Publication date: May 12, 2011Inventor: Manabu SHIOZAWA
-
Publication number: 20110044142Abstract: An optical disc apparatus includes a light source for emitting laser light, a light source drive unit for driving said light source, an optical element for splitting the laser light into a plurality of light fluxes, an optical element drive unit for controlling the optical element, an element for focusing the laser light onto the optical disc, and a detection unit for detecting the laser light reflected by the optical disc. Reproduction of the optical disc is performed by switching effectiveness and ineffectiveness of a function of splitting the light flux of the optical element, and adjustment of an outgoing laser power is performed.Type: ApplicationFiled: May 24, 2010Publication date: February 24, 2011Inventor: MANABU SHIOZAWA
-
Patent number: 7869333Abstract: The object of this invention is to provide an optical disc apparatus and an optical disc reproducing method that can realize an excellent reproducing operation by suppressing noise in the optical disc apparatus using an optical attenuator. In order to solve this object, a control voltage of the optical attenuator is changed according to reproduction power when reproducing the optical disc and an ambient temperature of the optical attenuator. In addition, the amplitude of a high frequency current for driving a laser diode is changed according to an attenuation factor of the optical attenuator.Type: GrantFiled: July 27, 2006Date of Patent: January 11, 2011Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.Inventors: Manabu Shiozawa, Kazutoshi Shigeta
-
Publication number: 20100202259Abstract: An optical disc apparatus for recording or reproducing on or from an optical disc, comprising a laser light source for emitting a laser beam; a drive portion for driving the laser light source; a detection portion for detecting the emission power of the laser beam; and means for focusing the laser beam onto the optical disc, wherein information is reproduced by a reproducing power varied according to a recording power to obtain reproducing signals having necessary quality while suppressing deterioration of the recording quality due to the reproducing power.Type: ApplicationFiled: November 19, 2009Publication date: August 12, 2010Applicants: Hitachi-LG Data Storage, Inc., Hitachi, Ltd.Inventor: Manabu SHIOZAWA