The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 12, 2001
Filed:
Dec. 19, 1997
Kiyoshi Nishimura, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
An object of the present invention is to provide a ferroelectric storage device which has long life in use. A switch-signal generating portion,automatically generates switch signals in predetermined timing. A reversal-of-polarity controlling portion,changes, on the switch signal, the polarity states of ferroelectric storage cells composing an information storage portion,. After that the reversal-of-polarity controlling portion,further performs a certain number of write operations or read-out operations on said ferroelectric storage cell so as to further move the polarity state in the direction of the changed polarity. A gate controlling portion,gives a control-of-input-gate signal and a control-of-output-gate signal to an input gate portion,and an output gate portion,thereby changing states of their operations. Therefore, the polarity state can be changed if required with the same data being stored in the ferroelectric storage cell. That prevent the ferroelectric storage cell from getting the bad electric property (imprint effect).