Patents by Inventor Yoshiyuki Miyabata
Yoshiyuki Miyabata 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).
-
Patent number: 6930968Abstract: A semiconductor laser driving apparatus for directing light to an optical disc for recording a recording mark based on a recording current and reproducing the recording mark to generate a reproduction signal. The apparatus includes a reproduction current generation section; a high frequency current generation section for generating a current including a high frequency component for reducing semiconductor laser noise in the reproduction; a recording current generation section, the recording current including a pulse corresponding to the recording mark and including a plurality of multi-pulses; and a current driving section for amplification. The apparatus further includes a filter to attenuate the enhanced high frequency components in the high frequency current and in the enhanced high frequency component; and a switching section for switching the filter so that the enhanced component in the recording current is superposed on at least one of the multi-pulses.Type: GrantFiled: March 16, 2001Date of Patent: August 16, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yuichi Kamioka, Toshiya Akagi, Yoshiyuki Miyabata, Yuichi Takahashi
-
Patent number: 6728178Abstract: Playback signal amplitude drops and continuity of the signal track amplitude is lost at the beginning the data recording area when data is incrementally written to optical discs such as DVD-R or DVD-RW media. Feed-forward control quickly settles semiconductor laser recording power to the target power level immediately after an incremental recording starts. While recording continues, feedback control maintains laser power at a desired recording power level even when the required current supply varies due to the temperature characteristics of the semiconductor laser when recording lasts for an extended period of time. A semiconductor laser control method and semiconductor laser control device thereby maintain laser power at a stable target recording power level quickly and for as long as recording continues.Type: GrantFiled: October 24, 2001Date of Patent: April 27, 2004Assignees: Matsushita Electric Industrial Co., Ltd., Victor Company of Japan LimitedInventors: Kenji Koishi, Yoshiyuki Miyabata, Makoto Usui, Kohjyu Konno, Yasuhiro Ueki, Tomonori Ueno, Yutaka Osada, Toru Fujimoto
-
Patent number: 6671248Abstract: A laser power controller detects the temperature and current setting used for the recording power during initial learning or the previous recording operation. When a new recording operation starts, the controller detects the temperature again and compared the detected temperature with the temperature at initial learning or the previous recording to adjust the current setting used for the previous recording power setting and set the initial recording power current of the new recording operation.Type: GrantFiled: May 18, 2001Date of Patent: December 30, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoshiyuki Miyabata, Toshiya Akagi
-
Patent number: 6621779Abstract: A power control device for controlling a power of a light source of an optical beam directed to an optical medium. The power control device includes a reflected light detector for detecting reflected light from the optical medium when irradiated by an optical beam which is following a track; an arithmetic unit for calculating from the reflected light a transmissivity of light transmitted from a disk surface to a recording layer or an amount of directed light on the recording layer of the medium; and power control means for controlling the power of the light source for emission based on a calculation result produced by the arithmetic unit.Type: GrantFiled: May 11, 2001Date of Patent: September 16, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Chikashi Inokuchi, Shigeru Furumiya, Yoshiyuki Miyabata, Yuji Hisakado, Atsushi Miyazaki, Toshiya Akagi
-
Patent number: 6408013Abstract: A semiconductor laser control method and a semiconductor laser control apparatus allow an outgoing radiation power of a semiconductor laser to be accurately stabilized to a desired value even if a characteristic of the semiconductor laser changes due to temperature variations or deterioration of life. The characteristic of a semiconductor laser is measured by a semiconductor laser characteristic detection unit and a target value is corrected by a target value correction unit based on a threshold current and differential quantum efficiency obtained from the measurement result. A power control unit controls the semiconductor laser by comparing the corrected target value with the output of a power detection unit, making it possible to achieve a desired outgoing radiation power of the semiconductor laser with high accuracy even if the threshold current or differential quantum efficiency of the semiconductor laser changes due to temperature variations or deterioration of life.Type: GrantFiled: April 6, 2000Date of Patent: June 18, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toshiya Akagi, Yoshiyuki Miyabata
-
Publication number: 20020070329Abstract: Playback signal amplitude drops and continuity of the signal track amplitude is lost at the beginning the data recording area when data is incrementally written to optical discs such as DVD-R or DVD-RW media. Feed-forward control quickly settles semiconductor laser recording power to the target power level immediately after an incremental recording starts. While recording continues, feedback control maintains laser power at a desired recording power level even when the required current supply varies due to the temperature characteristics of the semiconductor laser when recording lasts for an extended period of time. A semiconductor laser control method and semiconductor laser control device thereby maintain laser power at a stable target recording power level quickly and for as long as recording continues.Type: ApplicationFiled: October 24, 2001Publication date: June 13, 2002Inventors: Kenji Koishi, Yoshiyuki Miyabata, Makoto Usui, Kohjyu Konno, Yasuhiro Ueki, Tomonori Ueno, Yutaka Osada, Toru Fujimoto
-
Publication number: 20020024909Abstract: A semiconductor laser driving apparatus for directing light to an optical disc for recording a recording mark based on a recording current and reproducing the recording mark to generate a reproduction signal. The apparatus includes a reproduction current generation section; a high frequency current generation section for generating a current including a high frequency component for reducing semiconductor laser noise in the reproduction; a recording current generation section, the recording current including a pulse corresponding to the recording mark and including a plurality of multi-pulses; and a current driving section for amplification. The apparatus further includes a filter to attenuate the enhanced high frequency components in the high frequency current and in the enhanced high frequency component; and a switching section for switching the filter so that the enhanced component in the recording current is superposed on at least one of the multi-pulses.Type: ApplicationFiled: March 16, 2001Publication date: February 28, 2002Inventors: Yuichi Kamioka, Toshiya Akagi, Yoshiyuki Miyabata, Yuichi Takahashi
-
Publication number: 20020021641Abstract: A laser power controller detects the temperature and current setting used for the recording power during initial learning or the previous recording operation. When a new recording operation starts, the controller detects the temperature again and compared the detected temperature with the temperature at initial learning or the previous recording to adjust the current setting used for the previous recording power setting and set the initial recording power current of the new recording operation.Type: ApplicationFiled: May 18, 2001Publication date: February 21, 2002Inventors: Yoshiyuki Miyabata, Toshiya Akagi
-
Patent number: 6339579Abstract: In an optical disc apparatus, a semiconductor SLD driving device is mounted on an optical pickup in order to realize a high speed switching of drive current for a semiconductor laser diode (SLD), necessary for recording data. The SLD is placed. within 5 cm from the SLD driving device. The driving device becomes a heat source due to driving current of the SLD, and increases a temperature of the optical pickup. Since the temperature rises proportionally to power consumption, power saving is required. A voltage supplied to the driving device is controlled to be a minimum level necessary for keeping the driving device still working on basic functions. The SLD driving device is mounted to the optical pickup, and this driving device handles N pieces of input signals for setting semiconductor laser power and N pieces of switch-timing-input-signals for selecting respective input signals.Type: GrantFiled: April 7, 1999Date of Patent: January 15, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yuichi Kamioka, Kenji Koishi, Yoshiyuki Miyabata, Naoyuki Nakamura, Kenichi Tatehara, Ikuo Hidaka, Kiyoshi Nakamori
-
Patent number: 5930225Abstract: A two-layer optical disk has a first layer of a disk shaped recording medium for storing data and a second layer of a disk shaped recording medium placed over the first layer for storing data. Data blocks A, B, C are stored in the first layer in said order. Similarly, data blocks X, Y, Z are stored in the second layer in said order. When reading the data from the two-layer optical disk, the data blocks are read in the order of A, X, B, Y, C, Z.Type: GrantFiled: October 21, 1997Date of Patent: July 27, 1999Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Takashi Ishida, Mamoru Shoji, Shunji Ohara, Shinichi Konishi, Yoshito Aoki, Yoshiyuki Miyabata, Yuji Hisakado, Hironori Deguchi
-
Patent number: 5729525Abstract: A two-layer optical disk has a first layer of a disk shaped recording medium for storing data and a second layer of a disk shaped recording medium placed over the first layer for storing data. Data blocks A, B, C are stored in the first layer in said order. Similarly, data blocks X, Y, Z are stored in the second layer in said order. When reading the data from the two-layer optical disk, the data blocks are read in the order of A, X, B, Y, C, Z.Type: GrantFiled: June 20, 1996Date of Patent: March 17, 1998Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Takashi Ishida, Mamoru Shoji, Shunji Ohara, Shinichi Konishi, Yoshito Aoki, Yoshiyuki Miyabata, Yuji Hisakado, Hironori Deguchi
-
Patent number: 5418574Abstract: A video signal correction apparatus has a memory for storing a luminance value and color difference values for each pixel in an image, a horizontal color difference correction arrangement and a vertical color difference correction arrangement. The horizontal color difference correction arrangement includes a luminance change point detector for detecting leading and trailing edges, in which an area defined between the leading and trailing edges is a boundary between two colors. The colors in a region outside the boundary and adjacent to the edges are bleeding. The color difference values further outside the bleeding region are sampled to make reference color difference value. The reference color difference value is used for replacing the color difference values in the bleeding region to eliminate or reduce the bleeding color.Type: GrantFiled: October 8, 1993Date of Patent: May 23, 1995Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoshiyuki Miyabata, Hiroshi Onishi
-
Patent number: RE39952Abstract: A power control device for controlling a power of a light source of an optical beam directed to an optical medium. The power control device includes a reflected light detector for detecting reflected light from the optical medium when irradiated by an optical beam which is following a track; an arithmetic unit for calculating from the reflected light a transmissivity of light transmitted from a disk surface to a recording layer or an amount of directed light on the recording layer of the medium; and power control means for controlling the power of the light source for emission based on a calculation result produced by the arithmetic unit.Type: GrantFiled: August 20, 1999Date of Patent: December 25, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Chikashi Inokuchi, Shigeru Furumiya, Yoshiyuki Miyabata, Yuji Hisakado, Atsushi Miyazaki, Toshiya Akagi