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:
May. 28, 1991
Filed:
Jul. 03, 1989
John M McKee, Hillsboro Beach, FL (US);
Joseph T Downey, Coral Springs, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
Known LCD devices of the type having an upper polarizer (36), a liquid crystal cell (28), a lower polarizer (38) and a reflector (42) and working using ambient light to provide illumination lose contrast because the light passes twice through both polarizers. By providing a layer of light concentrating plastic (44) between the upper polarizer (36) and the LCD cell (28), light emitted from bevelled edges (48) of an aperture (46) in the plastic is directed towards the cell and reflector directly, without passing through the upper polarizer (36). This is in addition to the normal ambient light passing through the front polarizer. This increases the intensity of light reaching the observer (20) and thus the contrast of the display.