Patent assignee · JP · COMPANY

Japan Servo Co., Ltd.

161Patents
14Active
161Granted
43Portfolio score

Filing activity: Mar 15, 1974 → Jul 24, 2007 · 14 expiring within 5 years

Most-cited patents

PatentTitleAreaCited byStatus
US6335582B1 Permanent-magnet revolving electrodynamic machine with a concentrated winding stator Electricity 65 Expired
US5874795A Multi-phase permanent-magnet type electric rotating machine Electricity 63 Expired
US6179569A Liquid transportation apparatus Human Necessities 55 Expired
US5386161A Permanent magnet stepping motor Electricity 54 Expired
US5410200A Hybrid type stepping motor Electricity 46 Expired
US6153953A Multi-phase PM-type stepping motor Electricity 45 Expired
US5532531A Permanent magnet type brushless motor Electricity 44 Expired
US5128570A Permanent magnet type stepping motor Electricity 43 Expired
US5652606A Message card Emerging Cross-Sectional Technologies 43 Expired
US5854526A Three-phase permanent-magnet electric rotating machine Electricity 40 Expired
US4109170A Electric motor having frequency generator Physics 38 Expired
US4983867A Hybrid-type stepping motor Electricity 37 Expired
US6313558A Electric rotary machine having concentrated winding stator Electricity 35 Expired
US7242118B2 Toroidal-coil linear stepping motor, toroidal-coil linear reciprocating motor, cylinder compressor and cylinder pump using these motors Electricity 35 Expired
US6605883B2 Multi-phase flat-type PM stepping motor and driving circuit thereof Electricity 34 Expired
US5289064A Three-phase permanent magnet stepping motor Electricity 34 Expired
US6121712A Three-phase permanent magnet cascade claw type stepping motor Electricity 34 Expired
US4503368A Permanent magnet type stepping motor Electricity 34 Expired
USD564653S1 Propeller for an axial flow fan General 33 Expired
US6028377A Three-phase permanent magnet cascade claw type stepping motor Electricity 33 Expired
US6703803B2 Fan motor driving circuit Emerging Cross-Sectional Technologies 33 Expired
US6575936B1 Liquid infusion apparatus Human Necessities 31 Expired
US5964576A Impeller of centrifugal fan Mechanical Engineering; Lighting; Heating 31 Expired
US5708310A Permanent magnet type stepping motor Electricity 30 Expired
US6765321B2 Three-phase toroidal coil type permanent magnet electric rotating machine Electricity 30 Expired

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