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:
Nov. 22, 1994
Filed:
Aug. 19, 1993
Kenichi Takahira, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An IC card according to the present invention includes data processing means for processing data; a memory for storing a personal identification number; a power-supply terminal to which a power-supply voltage is applied by an external unit; an input/output terminal for inputting data from and outputting data to the external unit; a voltage detecting circuit for detecting the power-supply voltage applied to the power-supply terminal from the external unit; and a check-processing circuit for verifying a personal identification number input from the external unit by comparison with a personal identification number stored in the memory in response to a command for verifying applied to the input/output terminal when the power-supply voltage detected in the voltage detecting circuit is at least equal to a threshold voltage and constantly responding that an identification error has occurred when the power-supply voltage detected in the voltage detecting circuit is lower than the threshold voltage.