Inventor

Isao Fukushima

Inventor

Katsuta, JP

Overview

39→

Patents

1978–1990

Patent span

Electricity

Primary field (CPC H)

Patents· 39 as inventor

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

G11Bprimary

G11BInformation storage based on relative movement between record carrier and transducer19%

H02PControl or regulation of electric motors, electric generators or dynamo-electric converters14%

H03GControl of amplification12%

H04NPictorial communication, e.g. television12%

H03HImpedance networks, e.g. resonant circuits9%

Y10STechnical subjects covered by former uspc cross-reference art collections [xracs] and digests9%

H03DDemodulation or transference of modulation from one carrier to another5%

H03FAmplifiers4%

H03KPulse technique4%

G01RMeasuring electric variables2%

PatentTitleYear

4,956,729'Video signal preamplifier circuit'1990 4,847,742'Multi-channel inverter circuit'1989 4,774,598'Slow-motion device of magnetic recording and reproducing apparatus'1988 4,757,394'Auto-tracking apparatus of a magnetic recording/reproducing apparatus'1988 4,737,864'Still picture recording system with noise detection and frame counting during shift from reproduction of picture in motion to reproduction of still picture including an intermediate slow motion mode'1988 4,724,407'Integrated filter circuit having switchable selected parallel filter paths'1988 4,713,700'A recording circuit having means to automatically set the recording current of a magnetic recording head'1987 4,691,246'Apparatus for multiplex recording and reproduction of audio and video signals'1987 4,682,096'Switching regulator system for a motor driving circuit'1987 4,672,468'Magnetic recording apparatus with recording of first and second sound signals'1987 4,667,120'Integrated filter circuit with variable frequency characteristics'1987 4,667,168'Integrated circuit with a phase-locked loop'1987 4,651,067'Apparatus for driving brushless motor'1987 4,647,960'Vertical contour emphasis de-emphasis circuit'1987 4,613,914'Auto-tracking method and apparatus of a magnetic recording/reproducing apparatus'1986 4,607,293'Magnetic recording and reproduction system'1986 4,605,901'Frequency-voltage converter'1986 4,591,924'Multiplex magnetic recording and reproduction system'1986 4,591,798'FM signal demodulation circuit'1986 4,590,438'Bipolar transistor circuit with FET constant current source'1986 4,543,516'Speed and phase control system'1985 4,521,750'Characteristic switching circuit'1985 4,518,901'Motor control apparatus'1985 4,503,369'Power supply for plural brushless DC motors'1985 4,494,056'Motor driving circuit'1985 4,482,926'Method and apparatus for magnetic recording and reproducing'1984 4,460,953'Signal voltage dividing circuit'1984 4,358,797'Electronic editing control apparatus for a video tape recorder'1982 4,338,554'Automatic gain control apparatus for a motor servo system'1982 4,307,326'Drive system for a motor'1981 4,256,975'Limiter circuit for removing nose from demodulated signals'1981 4,214,299'Frequency-voltage converter'1980 4,198,602'Limiter circuit for limiting pulsive noises'1980 4,198,541'Signal holding circuit'1980 4,197,505'Limiter circuit'1980 4,190,836'Dynamic drive circuit for light-emitting diodes'1980 4,179,650'Variable impedance circuits'1979 4,146,842'Noise muting circuit in FM receiver'1979 4,122,394'Phase-shifting multiplication type FM signal demodulation circuit'1978

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1978–1990Patents assigned to HITACHI LTD (38)· patent assignee history

1978–1980Based in Fujisawa, JP· patent location history

1980–1989Based in Katsuta, JP· patent location history

1984–1988Patents assigned to HITACHI MICROCUMPUTER ENG (6)· patent assignee history

1986Patents assigned to ENGINEERING LTD (1)· patent assignee history

1986Patents assigned to HITACHI MICROCOMPUTER HITACHI (1)· patent assignee history

1987–1990Patents assigned to HITACHI VIDEO ENG (5)· patent assignee history

1990Based in Ibaraki, JP· patent location history

Inventor activity

Assignee and location history derived from the patent record.

Assignees

Assignee	Patents	Span
HITACHI LTD	38	1978–1990
HITACHI MICROCUMPUTER ENG	6	1984–1988
HITACHI VIDEO ENG	5	1987–1990
ENGINEERING LTD	1	1986
HITACHI MICROCOMPUTER HITACHI	1	1986

Locations

Location	Patents	Span
Katsuta, JP	32	1980–1989
Fujisawa, JP	6	1978–1980
Ibaraki, JP	1	1990