Selectively erasable electronic writing tablet
US8139039B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 2008 |
| Grant date | Mar 20, 2012 |
| Priority date | — |
| Expiry date | Nov 24, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13478
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electronic writing tablet is composed of one or more layers on which an image is formed and can be selectively erased. One aspect of the invention is a bistable cholesteric writing tablet on which an image is formed while applying writing pressure. The image can be fully erased and new images written on the tablet. In addition, one can selectively erase any or all portions of the written image to restore the original background color. Another aspect of the invention is a multi-color stacked writing tablet in which a color of an image is selected (usually by applying a suitable voltage) while applying writing pressure using an instrument such as an untethered stylus on the surface of the tablet. The writing tablet includes at least two or three stacked layers of bistable cholesteric liquid crystal material. Selected colors can be additively mixed to achieve intermediate colors as desired. The image can be fully erased and new images written on the tablet. In addition, one can selectively erase any or all portions of the written image to restore the original background color.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.