Patent assignee · JP · COMPANY

Sony Precision Technology Inc.

38Patents
0Active
38Granted
33Portfolio score

Filing activity: Sep 3, 1997 → Nov 10, 2003

Most-cited patents

PatentTitleAreaCited byStatus
US5970432A Apparatus and method for measuring displacement Physics 26 Expired
US6578283B2 Position transducer Physics 21 Expired
US6182191A Recording and reproducing system Physics 20 Expired
US6541747B1 Focal mechanism and method for controlling focal point position, and apparatus and method for inspecting semiconductor wafer Physics 20 Expired
US6236200A Magnetic metal sensor and method for detecting magnetic metal Physics 17 Expired
US6407815B2 Optical displacement measurement system Physics 15 Expired
US6980303B2 Light-emitting/receiving combined unit and displacement sensors using the same Physics 14 Expired
US7171039B2 Defect classification/inspection system Physics 13 Expired
US6768426B2 Position detection apparatus Physics 13 Expired
US6145214A Position detection apparatus Physics 12 Expired
US6145213A Position detection apparatus Physics 12 Expired
US6222361A Position detecting device using varying width magneto-resistive effect sensor Physics 12 Expired
US6541960B2 Position detector utilizing magnetic sensors and a bias magnetic field generator Physics 10 Expired
US6580264B2 Position detector with magnetic core and detection and auxiliary coils Physics 10 Expired
US6668996B2 Electromagnetic clutch Mechanical Engineering; Lighting; Heating 9 Expired
US6119357A Scale device Physics 9 Expired
US6772101B1 Position detection apparatus and arithmetic processing unit Physics 8 Expired
US6166817A Optical displacement measurement system for detecting the relative movement of a machine part Physics 8 Expired
US7034948B2 Displacement pickup Physics 8 Expired
US6583948B1 Disc recording/reproducing apparatus and servo signal writing apparatus Physics 8 Expired
US6788053B2 Magnetic flux measuring device Physics 6 Expired
US6070132A Position detecting apparatus Physics 5 Expired
US6490807B1 Position detection apparatus Physics 5 Expired
US6879405B2 Displacement pickup Physics 5 Expired
US6031885A Displacement detecting apparatus Physics 4 Expired

Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.