LexDanaLexDanabeta
Inventor

Yoshito Tsunoda

Inventor
Mitaka, JP

Overview

49→
Patents
1976–1999
Patent span
Physics
Primary field (CPC G)

Patents· 49 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 transducer67%
G03HHolographic processes or apparatus5%
G06FElectric digital data processing5%
H01SDevices using the process of light amplification by stimulated emission of radiation [laser] to amplify or generate light5%
G02BOptical elements, systems or apparatus3%
G06KGraphical data reading3%
H04NPictorial communication, e.g. television3%
Y10STechnical subjects covered by former uspc cross-reference art collections [xracs] and digests3%
B41JTypewriters2%
G01JMeasurement of intensity, velocity, spectral content, polarisation, phase or pulse characteristics of infrared, visible or ultraviolet light2%
PatentTitleYear
5,871,881'Multilayer optical information medium'19995,666,598'Image forming method and apparatus using energy beam impingement on image forming particles to move the same'19975,574,881'High capacity data storage method and system using independently controlled heads and circuitry for monitoring access frequency of data records'19965,572,699'Variable length data in a parallel disk array'19965,404,348'Method for recording and reproducing information using at least two energy beams'19955,327,371'Information recording and reproducing apparatus'19945,218,599'Method of recording and reproduction of information using a recording medium available for information overlap recording, a recording medium and a recording and reproducing apparatus using the method'19935,109,374'Small-sized optical memory device and information processing apparatus utilizing cylindrically shaped information recording medium'19925,084,860'Apparatus for optical disc memory with correction pattern and master disc cutting apparatus'19925,073,880'Information recording/reproducing method and apparatus'19915,025,268'Optical scanning apparatus and asymmetrical aspheric scanning lens'19914,985,616'Optical card having optical grooves for access and wobbled marks for tracking and a recording-reproducing apparatus therefor'19914,970,707'Optical tape apparatus with a tracking control mechanism and/or a focusing control mechanism'19904,953,152'Mastering machine for making an on-land recording master disk with two beam alignment servo loops'19904,949,331'Apparatus and record carrier for optical disc memory with correction pattern and master disc cutting apparatus'19904,879,703'Magneto-optic memory apparatus with defect detection of recording medium during erasing operation'19894,855,991'Optical disk having track offset detection areas'19894,835,756'Optical memory apparatus using an optical disc having guide-grooves of V-shape and predetermined optical depth and access method therefor'19894,815,058'Optical information processing apparatus'19894,807,210'Optical information processing apparatus'19894,802,153'Optical information processor and method for accessing rotating record carrier utilizing acousto-optic light deflector including holding a focus error signal during track jumping'19894,791,650'Phased-array semiconductor laser apparatus'19884,759,628'Wavelength scanning interferometry and interferometer employing laser diode'19884,742,218'Focus error detection apparatus utilizing focusing an front and rear sides of focal planes'19884,733,388'Information recording disc'19884,731,771'Tracking servo setting method and apparatus'19884,725,721'Autofocusing control system'19884,663,751'Optical information processor for compensating offset'19874,656,618'Optical information recording and reproducing apparatus'19874,622,564'Optical information recording apparatus'19864,563,760'Method of detecting light spot control signal'19864,556,965'Information recording apparatus having automatic focusing'19854,554,652'Optical information processor'19854,550,394'System for optically recording information'19854,532,522'Optical recording apparatus'19854,525,826'Optical track position detecting apparatus and optical information processor using the same'19854,523,089'Driving apparatus for semiconductor laser'19854,450,547'Focal position detecting optical apparatus'19844,308,612'Optical information recording apparatus including error checking circuit'19814,301,527'Optical head for a videodisc recorder/player'19814,298,974'Optical head for a videodisc player/recorder'19814,293,944'Information play-back apparatus with astigmatic auto-focusing'19814,283,785'Optical information recording apparatus'19814,163,149'Automatic focusing apparatus'19794,085,423'Information reproducing apparatus with plural beam readout'19784,051,528'Apparatus for optically reconstructing information'19774,037,919'Holographic device with divided object beams, a multicolor light source and direction-selective screen'19774,021,606'Hologram apparatus'19773,937,554'Holograms impregnated with laser active material'1976

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1976–1999Patents assigned to HITACHI LTD (49)· patent assignee history
1976–1999Based in Tokyo, JP· patent location history
1977–1992Based in Mitaka, JP· patent location history
1977Based in Hachioji, JP· patent location history
1979–1981Based in Stanford, CA, US· patent location history
1988–1990Patents assigned to HITACHI MAXELL (2)· patent assignee history
1988Patents assigned to KASAI MASUO (1)· patent assignee history
1988Patents assigned to MAEDA TAKESHI (1)· patent assignee history
1990–1996Based in Suginami-ku, JP· patent location history
1991Patents assigned to HITACHI KOKI KK (1)· patent assignee history

Inventor activity

Assignee and location history derived from the patent record.

Assignees
AssigneePatentsSpan
HITACHI LTD491976–1999
HITACHI MAXELL21988–1990
HITACHI KOKI KK11991
KASAI MASUO11988
MAEDA TAKESHI11988
Locations
LocationPatentsSpan
Mitaka, JP321977–1992
Tokyo, JP91976–1999
Suginami-ku, JP51990–1996
Stanford, California, US21979–1981
Hachioji, JP11977