Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA902249A
Inventor
Tsukuda Kiyoshi
Kamei Tatsya
Ogawa Takuzo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Publication date
Application grantedgrantedCritical
Publication of CA902249ApublicationCriticalpatent/CA902249A/en