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.

Date of Patent:
Jul. 12, 2011

Filed:

Sep. 28, 2008
Applicants:

Osamu Iwasaki, Kanagawa, JP;

Ryuichi Katsumoto, Fujinomiya, JP;

Inventors:

Osamu Iwasaki, Kanagawa, JP;

Ryuichi Katsumoto, Fujinomiya, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F21V 7/04 (2006.01);
U.S. Cl.
CPC ...
Abstract

The planar lighting device includes, in addition to light sources, a light exit plane, a pair of light entrance planes formed on a pair of sides of the light exit plane, and a rear plane composed of a pair of inclined planes formed on a side opposite from the light exit plane such that the light guide plate grows thicker with an increasing distance from the light entrance planes toward the center. The light guide plate contains light scattering particles satisfying Npi>Np, where Npi is the particle density in a region of space within a given range of the light guide plate and Np the density in the other region of space. The planar lighting device with minimized brightness unevenness liable to develop near the light entrance planes when the light exit plane has great dimensions.


Find Patent Forward Citations

Loading…