Patent Number: 6,801,285

Title: Thin cell gap microdisplays with optimum optical properties

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.

Inventors: Shi; Hongqin (San Jose, CA), Jepsen; Mary Lou (Sausalito, CA)

Assignee: Microdisplay Corporation

International Classification: G02F 1/13 (20060101); G02F 1/139 (20060101); G02F 1/136 (20060101); G02F 001/133 ()

Expiration Date: 10/02016