Patent Number: 6,310,713

Title: Optical system for miniature personal displays using reflective light valves

Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS. The SLM receives this second polarization of light after reflection thereof by the PBS, and selectively rotates the second polarization of light to form an image forming light having the first polarization, which is reflected back to the PBS. Through an exit face, the PBS provides the rotated image forming light to a viewer. Between the viewer and the PBS exit surface, an imaging lens system is provided that includes at least one folding mirror.

Inventors: Doany; Fuad Elias (Katonah, NY), Singh; Rama Nand (Bethel, CT)

Assignee: International Business Machines Corporation

International Classification: G02B 27/01 (20060101); G02B 5/30 (20060101); G02B 005/30 (); G02B 027/28 (); G02F 001/03 ()

Expiration Date: 10/30/2018