Dual-screen organic electroluminescent display

#1. Field of Invention

#The present invention relates to a dual-screen display, and more particularly to a dual-screen organic electroluminescent display.

#2. Related Art

#The present invention will become more fully understood from the detailed description given herein below illustration only, and is thus not limitative of the present invention:

#FIG. 1 is a schematic view of a dual-screen organic electroluminescent display device according to a first embodiment of the invention; and

#FIG. 2 is a schematic view of a dual-screen organic electroluminescent display device according to a second embodiment of the invention.

#The invention provides a dual-screen organic electroluminescent display device including two bottom-emission organic electroluminescent display panels. Referring to FIG. 1, illustrating a first embodiment of the invention, a bottom-emission organic electroluminescent display panel includes a transparent substrate 100, an organic electro-luminescent element and an insulation layer 140. The organic electroluminescent element is formed on the transparent substrate 100 and covered by the insulation layer 140. The organic electroluminescent element includes a plurality of organic electroluminescent materials 120, a plurality of transparent electrodes 110 and a plurality of metallic electrodes 130. The transparent electrodes 110 and the metallic electrodes 130 are respectively formed on opposite sides of the organic electroluminescent materials 120. The transparent electrodes are attached to the transparent substrate while the metallic electrodes are covered by the insulation layer to realize a single organic electroluminescent display panel. In this embodiment, the transparent electrodes 110 are first formed on the transparent substrate 100. Then, a plurality of organic electroluminescent materials 120 is deposited on the transparent electrodes 110. In order to get a good-performance organic electroluminescent element, the organic electroluminescent materials can choose from the electron hole injecting layer, the electron hole transport layer, the emitting layer, the electron transport layer, the electron injecting layer and the charge generating layer. The metallic electrodes 130 are formed on the organic electroluminance material 120, and the insulation layer 140 covers the metallic electrodes 130. Thereby, one bottom-emission organic electroluminescent display panel is accomplished. Two of the bottom-emission organic electroluminescent display panels above are further positioned face to face and then encapsulated with an UV-curing epoxy 150 to form the dual-screen organic electroluminescent display device.

#Alternatively, two display panels can be formed on one transparent substrate and encapsulated by a transparent lid. FIG. 2 is a schematic view of a dual-screen organic electroluminescent display device according to a second embodiment of the invention. In this embodiment, the dual-screen organic electroluminescent display device includes a transparent substrate 200, a top-emission organic electroluminescent element, a bottom-emission organic electroluminescent element, an insulation layer 240, and a transparent lid 260. A plurality of transparent electrodes 210 is formed on the transparent substrate 200. Then, a plurality of bottom-emission organic electroluminescent materials 220 is deposited on the transparent electrodes 210. In order to get a good-performance organic electroluminescent element, the organic electroluminescent materials can choose from the electron hole injecting layer, the electron hole transport layer, the emitting layer, the electron transport layer, the electron injecting layer and the charge generating layer. A plurality of metallic electrodes 230 is formed on the organic electroluminescent materials 220 to form the bottom-emission organic electro-luminescent element, which then is covered by the insulation layer 240. The top-emission organic electroluminescent element, which includes a plurality of metallic electrodes 231, a plurality of organic electroluminescent materials 221 and a plurality of transparent electrodes 211 subsequently formed on one another, is stacked on the insulation layer 240. The transparent electrodes 211 and the metallic electrodes 231 are respectively formed on opposite sides of the organic electroluminescent materials 221. The plurality of organic electroluminescent materials 221 can include an electronic hole injecting layer, an electronic hole transport layer, an emitting layer, an electron transport layer, an electron injecting layer, a charge generating layer, etc. The UV-curing epoxy 250 and a transparent lid 260 are used to encapsulate the display panels to realize the dual-screen organic electroluminescent display device.

#Each of the transparent electrodes can be made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), or a thin metal layer. The transparent substrate is made of glass or plastics, for example. The insulation layer covering the metallic electrodes has a dark or black color to avoid light crosstalk. According to the practical demand, these two organic electroluminescent display panels could be driven by two passive matrices, two active matrices or a combination mode of a passive matrix and an active matrix. In the display device of the invention, a 2×2 inch glass panel has a thickness that is reduced to the range of about 1.5 mm to 3 mm, and its weight is reduced to the range of about 15 g to 17 g. Furthermore, only one encapsulation step is required to encapsulate the display panels, which efficiently reduces the manufacture cost. Compared to the prior art, as shown in table 1, the thickness of the display device according to the invention is about ⅓ of that of the prior art. Similarly, the weight and the package cost of the display device according to the invention are about ½ of that of the prior art.