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:
Jun. 09, 1998
Filed:
Jun. 24, 1994
Fujitsu Limited, Kawasaki, JP;
Abstract
An object of the present invention is to provide a light guide device which can emit light rays of high directivity with high efficiency irrespective of incident angles, and a light source device using the light guide device which can provide light rays of high directivity with high efficiency irrespective of emitting characteristics of light source lamps, and a liquid crystal display device which is small-sized and can display at very high luminance and is free from color tone changes depending on visual angles over a wide field angle. A substantial point light source is contained in a reflection box having an inside wall coated with a silver reflecting surface and an opening in the shape of a pinhole formed in a surface of the reflection box, and the light guide device is provided in the pinhole-shaped opening. The light guide device is a cylindrical transparent body. An incident end surface of the light guide device has a 1 mm-diameter, and an exit end surface of the light guide device has a 6.2 mm-diameter and a 100 mm-length. Source light from the substantial light source enters the incident end surface of the light guide device through the pinhole-shaped opening, repeats total reflection within the light guide device to exit at the exit end surface in light rays of high directivity of about .+-.10.degree..