HK

Hirotaka Kawai

Yamaha: 12 patents #185 of 2,001Top 10%
FD Fdk: 11 patents #3 of 324Top 1%
Fujitsu Limited: 1 patents #14,843 of 24,456Top 65%
Overall (All Time): #185,532 of 4,157,543Top 5%
23
Patents All Time

Issued Patents All Time

Showing 1–23 of 23 patents

Patent #TitleCo-InventorsDate
8854716 Reflection type variable optical attenuator Hiroaki Ono, Hidenori Nakada, Yuko Ota, Taro Nakamura 2014-10-07
8289071 Charge pump Masato Miyazaki, Tatsuya Kishii, Masayoshi Nakamura, Ken Makino 2012-10-16
8284093 Successive approximation A/D converter 2012-10-09
8059834 Automatic gain control circuit Yasuomi Tanaka, Nobuaki Tsuji 2011-11-15
7990211 Class D amplifier circuit Nobuaki Tsuji, Yasuomi Tanaka 2011-08-02
7982522 Semiconductor integrated circuit for realizing an amplifier having ringing reduction circuitry Nobuaki Tsuji 2011-07-19
7948313 Class D amplifier circuit Nobuaki Tsuji 2011-05-24
7924089 Offset voltage correction circuit and class D amplifier Yasuomi Tanaka, Nobuaki Tsuji 2011-04-12
7920082 D/A converter circuit and digital input class-D amplifier Nobuaki Tsuji, Morito Morishima, Yohei Otani 2011-04-05
7912112 Spectrum spreading circuit Nobuaki Tsuji, Yasuomi Tanaka 2011-03-22
7830182 Comparator Masaya Suzuki, Yasuomi Tanaka, Nobuaki Tsuji 2010-11-09
7816992 Offset voltage correction circuit and class D amplifier Yasuomi Tanaka, Nobuaki Tsuji 2010-10-19
7679435 Digital input class-D amplifier Nobuaki Tsuji, Morito Morishima 2010-03-16
7336418 Optical attenuator Hiromitsu Umezawa, Isao Kojima, Hidenori Nakata, Teruhisa Sahashi 2008-02-26
7006273 Faraday rotation device and optical device using same Teruhisa Sahashi, Hidenori Nakada, Isao Kojima, Tsugio Tokumasu 2006-02-28
6906843 Ferrule attachment type optical isolator, and manufacturing method thereof Mitsuru Nagasawa 2005-06-14
6876480 Farady rotation device and optical device comprising it Teruhisa Sahashi, Hidenori Nakada, Isao Kojima, Tsugio Tokumasu 2005-04-05
6417952 Faraday rotation angle varying device Hiromitsu Umezawa 2002-07-09
6288827 Faraday rotator Hiromitsu Umezawa, Hidenori Nakada, Nobuhiro Fukushima 2001-09-11
6108120 Faraday rotation angle varying apparatus Hiromitsu Umezawa, Youichi Suzuki, Hidenori Nakada 2000-08-22
5965287 Magneto-optical element material and Faraday element using the same Toshiyasu Suzuki, Hiromitsu Umezawa 1999-10-12
5566017 Material for magneto-optical element and faraday rotator using the same Toshiyasu Suzuki, Hiromitsu Umezawa 1996-10-15
5547613 Magneto-optical element material formed of magnetic garnet single crystals Shinzo Fujii, Hiromitsu Umezawa 1996-08-20