Patent Application
20070147077
The present invention relates to backlight modules those used in liquid crystal displays (LCDs), and particularly to a backlight source which includes an organic light emitting layer having at least two light emitting portions and a liquid crystal display employing the backlight source.
A liquid crystal display (LCD) is capable of displaying a clear and sharp image through thousands or even millions of pixels that make up the complete image. The liquid crystal display has thus been applied to various electronic equipment in which messages or pictures need to be displayed, such as mobile phones and notebook computers. However, liquid crystal molecules in the liquid crystal display do not themselves emit light. Rather, the liquid crystal molecules have to be lit up by a light source so as to clearly and sharply display text and images. The light source may be ambient light, or a backlight source attached to the liquid crystal display.
Referring to
The first electrode layer 121 functions as an anode, is generally made from a transparent conductive material, such as indium tin oxide (ITO) or indium zinc oxide (IZO). The organic light emitting layer 123 is monolayer or multilayer organic film, and is formed by being vapor deposited or being spun on the first electrode layer 121. The second electrode layer 122 functions as a cathode, and is generally made from a metal.
When backlight source 120 is driven by a voltage, the first electrode layer 121 injects electric holes into the organic light emitting layer 123, and the second electrode layer 122 injects electrons into the organic light emitting layer 123. The electrons and the electric holes meet and bond, thus both returning a basic state from an excited state. Energy radiates in the form of rays.
However, in order to coordinate with an emitting area of the backlight source 120, the organic light emitting layer 123 generally has a large area. As a result, the organic light emitting layer 123 radiates heat slowly, and therefore is too hot, thus accelerating a deterioration speed thereof. Therefore, the backlight source 120 has a decreased useful time, and the liquid crystal display 100 has decreased use-cost.
Therefore, what is needed, is a new backlight source that can overcome the above-described problem. What is also needed is a liquid crystal display employing the backlight source.
In one preferred embodiment, a backlight source includes a first electrode layer, an organic light emitting layer, and a second electrode layer arranged in that order from one side of the backlight source to an opposite side of the backlight source. The organic light emitting layer includes at least two light emitting portions and a spacing portion located between the light emitting portions.
Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, all the views are schematic.
Referring to
Referring also to
When backlight source 220 is driven by a voltage, the first electrode layer 221 injects electric holes into the organic light emitting layer 223, and the second electrode layer 222 injects electrons into the organic light emitting layer 223. The electrons and the electric holes meet and bond, thus both returning a basic state from an excited state. Energy radiates in the form of rays.
In summary, because the organic light emitting layer 223 includes the spacing portion 2232 spacing the two light emitting portions 2231 thereof, the organic light emitting layer 223 has an increased heat radiating area. Thus, the organic light emitting layer 223 has an improved heat radiating capability, and has a slower deterioration speed. Therefore, the backlight source 220 has an increased useful time, and therefore the liquid crystal display 200 has reduced use-cost.
Referring to
Referring also to
Further or alternative embodiments may include the following. In one example, the first electrode layer 221 of the first embodiment functions as a cathode, and the second electrode layer 222 functions as an anode.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 94146351 | Dec 2005 | TW | national |
