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:
Oct. 20, 1992
Filed:
Nov. 21, 1990
Kenichi Takahira, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An IC card has a data transmission/receiving circuit for exchanging data with an external device, a data processing circuit connected to the data transmission/receiving circuit for processing the data, a battery for supplying the data transmission/receiving circuit and the data processing circuit with electrical power, a charge storage device such as a capacitor charged at a predetermined time constant by the battery, a charge control circuit for controlling connection of the battery to the charge storage device in accordance with a control signal from the data processing circuit, a comparator circuit for comparing the output voltage from the charge storage device with a reference value, and a time measuring counter for measuring the time from electrical connection of the battery to the charge storage device until the comparator circuit detects an output voltage from the charge storage circuit exceeding the reference value.