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:
Oct. 05, 2004
Filed:
Jan. 14, 2003
Hongqin Shi, San Jose, CA (US);
Mary Lou Jepsen, Sausalito, CA (US);
Microdisplay Corporation, San Pablo, CA (US);
Abstract
A projection mode microdisplay includes a silicon substrate having disposed thereon a first alignment layer having a first alignment direction, and a cover substrate having disposed thereon a second alignment layer having a second alignment direction. A liquid crystal material having spacers disbursed therethrough is disposed between to maintain the cell gap which is about 1.2 microns. The first and second alignment directions form about a 27 degree twist angle. An electrode disposed on the cover substrate and the silicon substrate are connected to a control system that sequentially applies an electric field across the cell gap to control the orientation of the liquid crystal material. A retarder is disposed on the cover substrate and has an alignment direction that is at −38 degrees ±5 degrees with respect to an x-axis of the display, wherein the liquid crystal material has a turn-on time no greater than 1.0 milliseconds and a turn-off time no greater than 4.0 milliseconds. The foregoing microdisplay has a contrast ratio of at least up to 2000:1, and a polarization conversion efficiency of at least 94%. A similar construction for a near-eye mode microdisplay utilizing a comparable thin cell gap can also be used.