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:
Oct. 06, 1998
Filed:
May. 22, 1995
Katsumi Kurematsu, Hiratsuka, JP;
Yoshihiro Onitsuka, Hiratsuka, JP;
Toshiyuki Kanda, Chigasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A backlight device suitable for illuminating a transmission-type display device, such as a liquid crystal device, is constituted by a reflection member for reflecting light, a transmission member disposed opposite to the reflection member so as to form a space from the reflection member, and a light source disposed to emit light into the space. Light issued from the light source into the space is reflected by the reflection member and transmitted through the transmission member. The transmission member is preferably provided with a reflection layer having apertures having an aperture ratio which increases with an increase in distance from the light source toward a center of the space in a linear function, a hyperbolic function or a function intermediate therebetween of the distance from the light source. Between the transmission member and the display device, a prism sheet and/or a diffusion sheet may be disposed so as to improve the frontal illumination performance.