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:
Dec. 21, 1999
Filed:
Feb. 23, 1998
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An EL driving apparatus is composed of a display portion, a photodiode as changing means for changing a reference voltage for controlling an increased voltage based on ambient brightness and a control portion for controlling the timing of discharging based on the reference voltage. The control portion has a comparator for comparing a specified peak value obtained by reducing the increased voltage generated by voltage increasing means with the reference voltage generated from within. The increased voltage is inputted to the control portion. The increased voltage is reduced to provide a detect voltage that can be inputted to the comparator. The comparator has a positive-phase input terminal for receiving the detect voltage and a negative-phase input terminal for receiving the reference voltage produced at a connection point between a constant current source and a resistor connected in series to each other. The photodiode is connected between the ground and the connection point between the constant current source and the resistor to form a reverse bias.