Patent assignee · JP · COMPANY

NEC Viewtechnology, Ltd.

125Patents
39Active
125Granted
46Portfolio score

Filing activity: Mar 24, 1999 → Jun 1, 2012 · 38 expiring within 5 years

Most-cited patents

PatentTitleAreaCited byStatus
US6819939B2 Cellular phone with high-quality sound reproduction capability Electricity 198 Expired
US6886942B2 Projector with light source having variable brightness based on detected temperature information Electricity 137 Expired
US7070281B2 Light source device and projection display Electricity 91 Expired
US6698891B2 Polarizing unit, polarizing illumination device using same polarizing unit and projection display device using same polarizing illumination device Physics 68 Expired
US6513935B2 Lens-less projection optical system of reflection type Electricity 54 Expired
US7880721B2 Wave receiving device and method of determining wave reception Physics 48 Active
US6846081B2 Projector Electricity 46 Expired
US6771427B1 Image-forming optical system Physics 31 Expired
US6950240B2 Imaging optical system Physics 29 Expired
USD504453S1 Projector General 29 Expired
US6644814B2 LED-illumination-type DMD projector and optical system thereof Physics 26 Expired
US6877862B2 Projector Physics 24 Expired
US6547402B2 Projection lens shifting mechanism Electricity 24 Expired
US7690797B2 Projector and focus adjustment method Electricity 24 Active
US7185987B2 Projector and projector accessory Electricity 23 Expired
US6491398B2 Video projector Electricity 22 Expired
US6877864B1 Projector and method of correcting image distortion Physics 21 Expired
US6574046B1 Reflective time-division image projector Electricity 19 Expired
US8086704B2 Projector selection system, projector selection method, and program for implementing the system and method Electricity 18 Active
US6687453B1 Digital image reproducing apparatus and method Electricity 17 Expired
US6494581B2 Lamp house and projector device thereof Physics 16 Expired
US6597409B1 Video projector Electricity 15 Expired
US7104653B2 System for correcting approximate expressions used in geometrical correction of projected images Physics 15 Expired
US6733137B2 Digital mirror device projector and method of correcting video signal being used in digital mirror device projector Electricity 14 Expired
USD500070S1 Projector General 13 Expired

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