News Column

Patent Issued for Light Emitting Device, Surface Illuminant, and Display Device

August 20, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- A patent by the inventors Ito, Shin (Osaka, JP); Okada, Yutaka (Osaka, JP), filed on November 10, 2009, was published online on August 5, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8794777 is assigned to Sharp Kabushiki Kaisha (Osaka, JP).

The following quote was obtained by the news editors from the background information supplied by the inventors: "There is a liquid crystal display device which includes, as a backlight which irradiates a liquid crystal display panel with light from behind, a surface illuminant in which light sources such as LEDs (light emitting diodes) are provided. Such a backlight, which irradiates a liquid crystal display panel with light from behind, is called a direct type backlight.

"Patent Literature 1 discloses a direct type backlight in which a plurality of LEDs are provided so as not to be in contact with each other. The respective plurality of LEDs emit light rays which are mixed to be uniform white light. The backlight includes (i) a base substrate, (ii) LEDs which are provided on the base substrate and emit blue light, red light, and green light, respectively, (iii) a diffusion plate which is provided above the LEDs, and (iv) lenses which are provided for the respective LEDs so as to cause emitted light to be directed toward the diffusion plate. Moreover, radiation angles of the respective lenses are adjusted so that the light rays emitted by the respective LEDs are mixed in a common area of the diffusion plate."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "Technical Problem

"Note, however, that, according to the backlight disclosed in Patent Literature 1, optic axes of the respective LEDs are directed in different directions, because of the configuration in which (i) the LEDs are provided so as not to be in contact with each other, (ii) the lenses are provided so as to cause the emitted light rays to be directed in a predetermined direction, and (iii) the common area of the diffusion plate is irradiated by the light rays. This may cause a phenomenon that colors, which are seen via the diffusion plate, are changed depending on an angle, because a spectral distribution changes depending on an emission direction.

"Moreover, the number of components is increased in accordance with the number of the lenses. Besides, it is necessary to adjust chromaticity after the lenses are provided. This leads to an increase in manufacturing cost. Moreover, this interferes with meeting demands of reduction in thickness and weight of backlight.

"The present invention is accomplished in view of the problem, and its object is to provide (i) a display device which has a thin body and hardly causes unevenness in luminance and in chromaticity, and (ii) a light emitting device and (iii) a surface illuminant, which are suitable for use in the display device.

"Solution to Problem

"A light emitting device of the present invention includes: a substrate; a semiconductor light emitting element provided on the substrate; a sealing member which is provided so as to cover the semiconductor light emitting element; and a lens made up of a plurality of convex parts and a concave part, the light emitting device emitting light having a non-concentric luminance distribution made up of a plurality of bright regions and a plurality of dark regions, the non-concentric luminance distribution being observed on a plane which is parallel to the substrate.

"Advantageous Effects of Invention

"According to the present invention, it is possible to provide a display device, which has a thin body but can suppress unevenness in luminance and in chromaticity, by combining the light emitting devices each of which has a non-concentric luminance distribution made up of the plurality of bright regions and the plurality of dark regions. Moreover, it is possible to provide the surface illuminant and the light emitting device each of which has a characteristic shape suitable for use in the display device."

URL and more information on this patent, see: Ito, Shin; Okada, Yutaka. Light Emitting Device, Surface Illuminant, and Display Device. U.S. Patent Number 8794777, filed November 10, 2009, and published online on August 5, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8794777.PN.&OS=PN/8794777RS=PN/8794777

Keywords for this news article include: Electronics, Semiconductor, Sharp Kabushiki Kaisha.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Electronics Newsweekly


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters