BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating an electroluminescence panel.
FIG. 2 is a schematic diagram illustrating a reflective organic electroluminescence panel according to a first preferred embodiment of the present invention.
FIG. 3 is a schematic diagram illustrating an organic electroluminescence display according to a second preferred embodiment of the present invention.
DETAILED DESCRIPTION
Please refer to FIG. 2. FIG. 2 is a schematic diagram illustrating a reflective organic electroluminescence panel according to a first preferred embodiment of the present invention. As shown in FIG. 2, the preferred embodiment of the reflective organic electroluminescence panel 50 comprises a first transparent substrate 52, a pair of first transparent electrodes 54,58 disposed on one side of the first transparent substrate 52, a first luminescence layer 56 disposed between the first transparent electrodes 54,58, a second transparent electrode 60 disposed on one side of the first substrate 52, a reflective electrode 62 disposed on the other side of the second transparent electrode 60 opposite to the first transparent substrate 52, and a second luminescence layer 64 disposed between the second transparent electrode 60 and the reflective electrode 62. Also, in the embodiment the reflective organic electroluminescence panel 50 comprises a protection layer 72, constituted by an organic material layer 66, a silicon oxide layer 68, and a silicon nitride layer 70, which encapsulates and protects the reflective organic electroluminescence panel 50. The reflective organic electroluminescence panel 50 further includes an external control device connection area 74 used to connect the reflective organic electroluminescence panel 50 and at least one external control device 110 disposed on the first transparent substrate 52.
The reflective organic electroluminescence panel 50 of the present invention is a single-side display panel. In addition, the display surface faces in the direction of the arrow sign shown in FIG. 2. The first luminescence unit of the reflective organic electroluminescence panel 50 is composed of the first transparent electrodes 54,58 and the first luminescence layer 56 disposed between the first transparent electrodes 54,58. Because the first transparent electrodes 54,58 are transparent conductive material, the first luminescence layer 56 will generate the light that radiates up and down separately when the image is displaying. Moreover, the light emitted upward directly provides part of the brightness, and the light emitted downward will pass through the first transparent substrate 52, and then the light will be reflected by the reflective electrode 62 to the direction of the display surface in order to provide part of the brightness. On the other hand, disposed on one side of the first transparent substrate 52 are the second transparent electrode 60, the reflective electrode 62, and a second luminescence layer 64, which constitute the second luminescence unit of the reflective organic electroluminescence panel 50. The light generated by the second luminescence layer 64 also will emit upward and downward. The light emitted upward will pass through the first transparent substrate 52 to the display surface and contribute to the part of the brightness. The light emitted downward will be reflected by the reflective electrode to the direction of display surface and provide part of the brightness. Therefore, the reflective organic electroluminescence panel 50 according to the embodiment generates the brightness that is provided by two simultaneous emitting luminescence units. For this reason, the brightness can reach over twice as bright as the bright of a luminescence unit of the electroluminescence panel.
The transparent substrate of the reflective organic electroluminescence panel according to the embodiment can be inorganic transparent material, such as glass, quartz, or organic transparent material, such as plastic. Transparent electrodes can be made out of transparent conductive material, such as AINd or indium tin oxide. The reflective electrode can be made out of material having good conductivity and reflectivity, such as silver, nickel, gold, or platinum. The material of the luminescence layer can be organic luminous material or polymer luminous material. Otherwise, the protection layer of the embodiment is a multi-layer structure composed of organic material, silicon oxide, and silicon nitride. However, the protection layer also can be a single layer structure whose material can be any suitable material. In addition, in order to improving the injection and transport efficiency of holes and electrons, it depends on requirements to dispose the hole injection layer, the hole transport layer, the electron injection layer and the electron transport layer between the luminescence layer and the electrode. Besides, the reflective organic electroluminescence panel can be an active or passive organic light emitting diode display panel or a polymer light emitting diode display panel.
Please refer to FIG. 3. FIG. 3 is a schematic diagram illustrating the organic electroluminescence display according to a second preferred embodiment of the present invention. The organic electroluminescence display of the embodiment comprises a reflective organic electroluminescence panel of the above-mentioned embodiment. Further, the same device is used by the same device symbol. As shown in FIG. 3, the organic electroluminescence display of the embodiment comprises a reflective organic electroluminescence panel 50, and a transmissive organic electroluminescence panel 80 disposed on the reflective organic electroluminescence panel 50. The reflective organic electroluminescence panel 50 comprises a first transparent substrate 52, a pair of first transparent electrodes 54,58 disposed on one side of first transparent substrate 52, a first luminescence layer 56 disposed between the first transparent electrodes, a second transparent electrode 60 disposed on one side of the first substrate 52, a reflective electrode 62 disposed on the other side of the second transparent electrode 60 opposite to the first transparent substrate 52, and a second luminescence layer 64 disposed between the second transparent electrode 60 and the reflective electrode 62. Besides, the reflective organic electroluminescence panel 50 also comprises a protection layer encapsulating and protecting the reflective organic electroluminescence panel 50 and an external control device connection area 74 disposed on the first transparent substrate 52.
The transmissive organic electroluminescence panel 80 comprises a second transparent substrate 82, a pair of third transparent electrodes 84,88 disposed on one side of second transparent substrate 82 facing the reflective organic electroluminescence panel 50, a third luminescence layer 86 disposed between the third transparent electrodes 84,88, a pair of fourth transparent electrodes 90,94 disposed on the other side of second transparent substrate 82 opposite to the reflective organic electroluminescence panel 50 and a fourth luminescence layer 92 disposed between the fourth transparent electrodes 90,94. Otherwise, the transmissive organic electroluminescence panel 80 also comprises a protection layer 96 encapsulating and protecting transmissive organic electroluminescence panel 80 and an external control device connection area 98 used for receiving the signal from at least one external control device 120 disposed on the second transparent substrate 82. Besides, in the embodiment the external control device connection area 74 of the reflective organic electroluminescence panel 50 and the external control device connection area 98 of the transmissive organic electroluminescence panel 80 are connected with electricity by making use of a conductive connecting device 100. For this reason, the reflective organic electroluminescence panel 50 and the transmissive organic electroluminescence panel 80 can be driven by the same control circuits. However, applications of the present invention are not restricted to this embodiment only. Therefore, the external control device connection area 74 of the reflective organic electroluminescence panel 50 and the external control device connection area 98 of the transmissive organic electroluminescence panel 80 do not need to be connected with electricity, and instead, can be controlled with an independent way.
According to FIG. 3, the organic electroluminescence display of the embodiment comprises a reflective organic electroluminescence panel 50, and a transmissive organic electroluminescence panel 80. In addition, two sides of the first transparent substrate 52 of the reflective organic electroluminescence panel 50 and two sides of the second transparent substrate 82 of the transmissive organic electroluminescence panel 80 all comprise luminescence units. Therefore, because the organic electroluminescence display has rather four luminescence units, display brightness could be four times the brightness of an electroluminescence panel that has only one luminescence unit. The organic electroluminescence display of the embodiment is not only restricted by using a transmissive organic electroluminescence panel 80, but also combines several transmissive organic electroluminescence panels 80 according to the demands of brightness specification. In other words, the organic electroluminescence display of the embodiment regards a reflective organic electroluminescence panel 50 as a basic unit. According to the brightness demands, combining one or several transmissive organic electroluminescence panels 80 could improve brightness performance. Under the operating conditions, for the reflective organic electroluminescence panel 50 and the transmissive organic electroluminescence panel 80, it is unnecessary to use high driving voltage way to improve brightness. Therefore, the total brightness of the organic electroluminescence display can be substantially improved, and the lifespan of the organic electroluminescence display can be extended.
In summary, the organic electroluminescence display of the present invention has advantages of high brightness and long lifespan. In addition, it is easier to guide into production by using the module method of combining the reflective organic electroluminescence panel and the transmissive organic electroluminescence panel.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Patent Application
20070273278
