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:
Feb. 11, 2020
Filed:
Apr. 13, 2018
Kent Displays Inc., Kent, OH (US);
Duane Marhefka, Winona, OH (US);
Kent Displays Inc., Kent, OH (US);
Abstract
A liquid crystal writing device includes a dispersion of cholesteric liquid crystal and polymer; a flexible substrate on which a user applies pressure that changes a texture of the cholesteric liquid crystal to form an image; electrically conductive layers between which the dispersion is disposed; and electronics adapted to apply an erase voltage waveform across the electrically conductive layers that forms a focal conic texture and erases the image. The erase voltage waveform includes: i) an erase portion at an erase voltage VE, the erase voltage VE being at least as high as a planar to homeotropic transition start voltage (VPH) of the cholesteric liquid crystal, and ii) a slow discharge portion that lasts for a time tthat is at least 10 ms.