Patent assignee · JP · COMPANY

Hitachi Engineering Co., Ltd.

199Patents
6Active
199Granted
43Portfolio score

Filing activity: Mar 28, 1978 → Jan 29, 2008 · 6 expiring within 5 years

Most-cited patents

PatentTitleAreaCited byStatus
US4481573A Shared virtual address translation unit for a multiprocessor system Physics 116 Expired
US4928107A Signal receiving method for a user's device in a global positioning system Physics 114 Expired
US5748202A Image data processor for processing pixel data in block buffer Physics 100 Expired
US4523286A Apparatus for making diagnosis of valve device in turbine system Emerging Cross-Sectional Technologies 93 Expired
US4245182A Excitation control apparatus for a generator Emerging Cross-Sectional Technologies 90 Expired
US5046023A Graphic processing system having bus connection control capable of high-speed parallel drawing processing in a frame buffer and a system memory Physics 78 Expired
US4622275A Fuel cell power plant Emerging Cross-Sectional Technologies 67 Expired
US5058114A Program control apparatus incorporating a trace function Physics 67 Expired
US4523272A Bus selection control in a data transmission apparatus for a multiprocessor system Physics 65 Expired
US5051932A Method and system for process control with complex inference mechanism Emerging Cross-Sectional Technologies 64 Expired
US4879502A Speed control apparatus and method for motors Electricity 58 Expired
US4839846A Apparatus for performing floating point arithmetic operations and rounding the result thereof Physics 56 Expired
US5251285A Method and system for process control with complex inference mechanism using qualitative and quantitative reasoning Emerging Cross-Sectional Technologies 55 Expired
US4811269A Bit slice multiplication circuit Physics 51 Expired
US4779210A Graphic processing apparatus Physics 49 Expired
US5011652A Nuclear power facilities Emerging Cross-Sectional Technologies 48 Expired
US4862150A Graphic pattern processing apparatus Physics 47 Expired
US4530050A Central processing unit for executing instructions of variable length having end information for operand specifiers Physics 46 Expired
US6504587B1 Liquid crystal display device in which the inner frame having sidewall Physics 44 Expired
US6198334A CMOS circuit Electricity 42 Expired
US5293558A Multiplication, division and square root extraction apparatus Physics 42 Expired
US5682552A Data communication adapter and data communication terminal apparatus for performing data transmission and reception between terminals Physics 41 Expired
US5203159A Pressurized fluidized bed combustion combined cycle power plant and method of operating the same Emerging Cross-Sectional Technologies 40 Expired
US5025499A Process control method and control system Emerging Cross-Sectional Technologies 40 Expired
US4894768A Data processing system with coprocessor Physics 40 Expired

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