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:
May. 14, 1991
Filed:
Apr. 16, 1990
Etsuo Okaue, Suwa, JP;
Masaru Egawa, Suwa, JP;
Yoshihiko Kasai, Suwa, JP;
Norio Horaguchi, Suwa, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
Electronic sunglasses of the transmittance-varying type including liquid crystal panels employing the electro-optical effect and a solar cell used as a power source. The electronic sunglasses include a voltage detecting circuit having such a hysteresis characteristic so as to output a signal for changing transmittance of the liquid crystal panel from a high mode to a low mode at at least high predetermined voltage or illumination, and changing transmittance from a low mode to a high mode at at least a low voltage or illumination. The sunglasses also include a first switch which operates at at least two switch positions, one switch position having a first stage of illumination at less than 20,000 Lux and a second stage of illumination at 20,000 Lux or greater at which transmittance is changed from a high mode and another switch position disabling the voltage detecting circuit. Also included is a second switch which operates to change transmittance from a high mode to a low mode independently of the set voltage value in the voltage detecting circuit according to the hysteresis effect.