Inventor

Masayuki Iwamatsu

Inventor

Hamamatsu, JP

Overview

30→

Patents

1978–2013

Patent span

Electricity

Primary field (CPC H)

Patents· 30 as inventor

Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.

H03Fprimary

H03FAmplifiers33%

H04SStereophonic systems23%

H03GControl of amplification15%

H03MCoding8%

H04BTransmission5%

H04RLoudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducers5%

Y10STechnical subjects covered by former uspc cross-reference art collections [xracs] and digests5%

G06JHybrid computing arrangements3%

G11BInformation storage based on relative movement between record carrier and transducer3%

H04NPictorial communication, e.g. television3%

PatentTitleYear

8,483,407'Noise reducing circuit'2013 8,265,283'Acoustic processing device and acoustic processing method'2012 8,164,388'Amplifying apparatus'2012 8,149,057'Signal processing circuit'2012 8,050,425'Audio signal supplying device, parameter providing system, television set, AV system, speaker apparatus, and audio signal supplying method'2011 7,961,011'Amplifier'2011 7,961,044'Amplifier'2011 7,551,031'Amplifier'2009 7,482,870'Class D amplifier'2009 5,999,630'Sound image and sound field controlling device'1999 5,727,067'Sound field control device'1998 5,680,464'Sound field controlling device'1997 5,524,053'Sound field control device'1996 5,046,107'Input level adjusting circuit'1991 5,040,220'Control circuit for controlling reproduced tone characteristics'1991 5,027,687'Sound field control device'1991 4,910,515'Digital signal processing circuit'1990 4,899,150'Digital signal processing circuit'1990 4,856,064'Sound field control apparatus'1989 4,851,842'Analog-to-digital conversion circuit'1989 4,745,298'Signal selection circuit'1988 4,476,442'Amplifier with distortion cancellation'1984 4,356,452'Class A push-pull amplifier with bias controlling circuit'1982 4,302,727'Power amplifier having bias circuit with temperature compensation'1981 4,241,314'Transistor amplifier circuits'1980 4,217,555'Amplifier circuit arrangement with stabilized power-supply current'1980 4,137,506'Compound transistor circuitry'1979 4,121,169'Amplifier device'1978 4,087,759'Power amplifier devices'1978 4,077,012'Amplifier devices'1978

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1978–1988Patents assigned to NIPPON MUSICAL INSTRUMENTS MFG (10)· patent assignee history

1978–2013Based in Hamamatsu, JP· patent location history

1981–2009Based in Shizuoka, JP· patent location history

1989–2013Patents assigned to YAMAHA CORP (19)· patent assignee history

1989–2013Patents assigned to IWAMATSU MASAYUKI (5)· patent assignee history

Inventor activity

Assignee and location history derived from the patent record.

Assignees

Assignee	Patents	Span
YAMAHA CORP	19	1989–2013
NIPPON MUSICAL INSTRUMENTS MFG	10	1978–1988
IWAMATSU MASAYUKIself	5	1989–2013

Locations

Location	Patents	Span
Hamamatsu, JP	28	1978–2013
Shizuoka, JP	2	1981–2009