Inventor · disambiguated record

Masahiro Birukawa

Also filed as: BIRUKAWA MASAHIRO

56 granted patents·5 pending applications·531 citations·filing 1983–2011

98Inventor score

Technology areasG11B Y10T H01F Y10S

Files withMATSUSHITA ELECTRIC INDUSTRIAL CO LTD40 PANASONIC CORP7 NARUMI KENJI4 TANAKA YASUHIRO2 AIKOH HIDEKI1

Top patents by PatentIndex Score

61 records

0195US6188649B1Method for reading magnetic super resolution type magneto-optical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1999·Granted Feb 13, 2001·76 cites·2 claims
0293US5422874AOptical recording disk, and recording/reading apparatus using sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1993·Granted Jun 6, 1995·67 cites·17 claims
0392US6982932B2Recording/reproducing head and recording/reproducing apparatus incorporating the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2003·Granted Jan 3, 2006·28 cites·5 claims
0487US5724338ARewritable disk-shaped optical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1996·Granted Mar 3, 1998·48 cites·21 claims
0584US5656370AOptical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1995·Granted Aug 12, 1997·42 cites·14 claims
0680US8179768B2Optical system for compensating for spherical aberration and/or coma aberration in an optical pickup device and optical pickup device having the sameTANAKA YASUHIRO·Filed 2008·Granted May 15, 2012·3 cites·60 claims
0779US7944799B2Optical information apparatus with gap control systemPANASONIC CORP·Filed 2007·Granted May 17, 2011·4 cites·7 claims
0878US5341359AAbnormality detection of a recording medium in a magneto-optical recording systemMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1992·Granted Aug 23, 1994·26 cites·17 claims
0976US5821004AMagneto-optical recording medium and recording and reading out process using the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1992·Granted Oct 13, 1998·23 cites·9 claims
1076US5582891AOptical disk substrate with land planes of uniform heightMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1993·Granted Dec 10, 1996·19 cites·14 claims
1175US8050150B2Near-field light detection element and information reproducing medium reproducing methodPANASONIC CORP·Filed 2009·Granted Nov 1, 2011·2 cites·14 claims
1272US6690626B2Optical disk with magnetic layer separated magnetically between tracks and method of magnetically separating tracks of the optical diskMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2002·Granted Feb 10, 2004·9 cites·3 claims
1371US6504796B1Magneto-optical head having thickness of the core same as a track widthMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2000·Granted Jan 7, 2003·6 cites·27 claims
1470US8233372B2Optical system for compensating for coma aberration and/or spherical aberration in an optical pickup device and optical pickup device having the sameTANAKA YASUHIRO·Filed 2008·Granted Jul 31, 2012·1 cites·18 claims
1567US8130623B2Optical information recording and/or reproducing apparatus, optical information recording and/or reproducing method, optical information recording medium, and solid immersion lensNARUMI KENJI·Filed 2009·Granted Mar 6, 2012·1 cites·12 claims
1667US7948835B2Optical disc device, method for activating optical disc device, and control circuitPANASONIC CORP·Filed 2009·Granted May 24, 2011·1 cites·10 claims
1767US7180831B2Magneto-optical recording medium having a recording layer of columnar structureMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2002·Granted Feb 20, 2007·6 cites·25 claims
1865US5993937AMagneto-optic recording medium and method of fabricating the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1994·Granted Nov 30, 1999·14 cites·7 claims
1964US8279721B2Near-field recording head capable of directly forming light source in sliderAIKOH HIDEKI·Filed 2007·Granted Oct 2, 2012·1 cites·12 claims
2064US6018511AMagneto-optical recording medium and readout method of the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1997·Granted Jan 25, 2000·17 cites·20 claims
2162US6747919B2Magneto-optical recording medium, and method and apparatus for producing the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2002·Granted Jun 8, 2004·5 cites·20 claims
2262US5986977AMethod for reading magnetic super resolution type magneto-optical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1997·Granted Nov 16, 1999·10 cites·3 claims
2361US5247495AOptical magnetic disk with separate regions provided on itMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1991·Granted Sep 21, 1993·12 cites·6 claims
2460US6765847B2Optical disk and method of magnetically separating tracks of the optical diskMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2002·Granted Jul 20, 2004·4 cites·18 claims
2560US6146740AMagnetic recording medium and method of fabricating the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1999·Granted Nov 14, 2000·18 cites·9 claims
2660US5706259AMagneto-optical recording medium for magnetically induced super resolutionMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1995·Granted Jan 6, 1998·15 cites·19 claims
2758US6650598B2Magnetic head having magnetoresistance device and recording/reproducing apparatus incorporating the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2002·Granted Nov 18, 2003·2 cites·26 claims
2856US8526293B2Information recording medium and recording/reproducing method for the sameKOJIMA RIE·Filed 2009·Granted Sep 3, 2013·0 cites·13 claims
2956US8422341B2Device and method for recording and/or reproducing data onto/from information recording medium by using near-field light and information recording mediumNARUMI KENJI·Filed 2008·Granted Apr 16, 2013·0 cites·18 claims
3055US8259541B2Optical recording/reproduction method, optical recording/reproduction device, program, and optical recording mediumITO EIICHI·Filed 2009·Granted Sep 4, 2012·0 cites·19 claims
3155US7957232B2Gap controller and optical information processorPANASONIC CORP·Filed 2008·Granted Jun 7, 2011·0 cites·6 claims
3255US7180842B2Optical disc cutting apparatus and method for manufacturing optical discMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2002·Granted Feb 20, 2007·2 cites·10 claims
3353US8040774B2Optical disk device and tilt correction method for optical disk devicePANASONIC CORP·Filed 2009·Granted Oct 18, 2011·0 cites·7 claims
3453US7773343B2Magnetic recording medium, and manufacturing method, manufacturing apparatus, recording and reproduction method, and recording and reproduction apparatus for the samePANASONIC CORP·Filed 2005·Granted Aug 10, 2010·0 cites·21 claims
3553US6018505AMagneto-optical disc apparatusMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1997·Granted Jan 25, 2000·10 cites·14 claims
3652US7235313B2Magneto-optical recording medium, method of manufacturing magneto-optical recording medium, method of recording on magneto-optical recording medium, and method of reproduction from magneto-optical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2003·Granted Jun 26, 2007·1 cites·31 claims
3751US6178151B1Optical head having a reproducing optical system and filter formed by light passing therethroughMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1998·Granted Jan 23, 2001·9 cites·30 claims
3850US8130625B2Optical information recorder/reproducer, optical information recording/reproducing method and control circuitNARUMI KENJI·Filed 2007·Granted Mar 6, 2012·0 cites·13 claims
3950US7420889B2Optical disc tracking control device, tracking control method, and tracking control programMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2003·Granted Sep 2, 2008·1 cites·10 claims
4044US4497870AMagneto-optical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1983·Granted Feb 5, 1985·6 cites·5 claims
4144US2007243417A1Magnetic Recording Medium, and Manufacturing Method and Manufacturing Apparatus of the Same, Recording and Reproduction Method of Magnetic Recording Medium, and Recording and Reproduction Apparatus of the SameMURAKAMI MOTOYOSHI·Filed 2005·Application pending·0 cites
4243US6811889B2Magneto-optical recording medium having a GDFECO readout magnetic filmMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2002·Granted Nov 2, 2004·0 cites·7 claims
4343US6307819B1Method of reading magneto-optical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1999·Granted Oct 23, 2001·3 cites·2 claims
4443US5814418AMagneto-optical recording medium and method for reading out information from the sameMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1995·Granted Sep 29, 1998·6 cites·10 claims
4543US5472758AOptical recording medium for short-wavelength of laser beam and read/write/erase method using the mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1993·Granted Dec 5, 1995·5 cites·8 claims
4642US6521357B1Magneto-optical recording mediumMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2000·Granted Feb 18, 2003·0 cites·5 claims
4742US5748592ADisk drive apparatus and disk storage medium for high density recordingMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1997·Granted May 5, 1998·5 cites·9 claims
4841US8385161B2Optical information reproducing device, optical information reproducing method and integrated circuitPANASONIC CORP·Filed 2010·Granted Feb 26, 2013·0 cites·11 claims
4941US5679386AOptical disk formation member for making an optical disk substrateMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 1995·Granted Oct 21, 1997·7 cites·8 claims
5041US2004057343A1Magnetic recording medium, method for producing the same and magnetic recording/reproducing apparatusMATSUSHITA ELECTRIC INDUSTRIAL CO LTD·Filed 2003·Application pending·0 cites

Showing the top 50 of 61 patent records by PatentIndex Score.

Join the waitlist — get patent alerts

Get an alert when Masahiro Birukawa files or is granted a new patent.

We store only your email — no account needed. See our privacy policy.

Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →