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:
Dec. 04, 1990
Filed:
Oct. 02, 1989
David L Bond, Hoffman Estates, IL (US);
Kevin D Kaschke, Schaumburg, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
Improved backlighting apparatus evenly illuminates positive and negative LCDs under all ambient lighting conditions. Incandescent lamps (301-304) provide light for distribution by a light pipe (101). The bottom of the light pipe (101) is selectively painted white to reflect light to the top of the light pipe (101) while the unpainted areas reflect light internal to the light pipe (101), controlling hot and dim spots. The corners of the light pipe (101) near the lamps (301-304) are dual angled to reflect the light into the center of the display. The burn-out of a lamp (301-304) will not substantially affect the even lighting capabilities of the apparatus.