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:
Jan. 23, 1996
Filed:
Apr. 06, 1995
Murakami Kaimeido Co., Ltd., , JP;
Abstract
In a device for driving an EC antiglare mirror in which reflectivity is variably controlled by an EC element, a surrounding light quantity detection circuit detects quantity of light surrounding a vehicle. A rear light quantity detection circuit detects quantity of light in the rear of the vehicle. An oscillation circuit is constructed so that duration of an 'H' level of an oscillation signal and duration of an 'L' level of the oscillation signal are individually controlled. An inversion period control circuit variably controls duration of one of the 'H' and 'L' levels of the oscillation signal generated by the oscillation circuit in response to light quantity detected by the surrounding light quantity detection circuit and also variably controls duration of the other level in response to light quantity detected by the rear light quantity detection circuit. An EC element drive circuit inverts, in accordance with the level of the oscillation signal, the polarity of drive voltage supplied from a drive power source and applies the inverted voltage to the EC element and thereby controls the amount of coloration in accordance with duty factor of the oscillation signal.