CROSS-REFERENCE TO RELATED APPLICATIONSThis application is a re-issue of U.S. patent application Ser. No. 15/109,410, filed on Jun. 30, 2016, now U.S. Pat. No. 9,692,006 issued on Jun. 27, 2017, where U.S. patent application Ser. No. 15/109,410 is an application of National Stage Entry of PCT/CN2014/095335, filed on Dec. 29, 2014, and claims priority to Chinese Foreign Priority Document CN 201310749017 filed on Dec. 31, 2013.
TECHNICAL FIELDThe present invention relates to an organic light-emitting diode (OLED) device and in particular to a transparent OLED device and a display device using the transparent OLED device.
BACKGROUNDOLED devices are active light-emitting devices. Compared with thin-film transistor LCDs (TFT-LCDs) in the existing mainstream flat panel display technology, OLEDs, due to their advantages such as high contrast, wide angle of view, low power consumption, thinner size and the like, are expected to become the flat panel display technology of the next generation, and are one of technologies that are highly concerned among the existing flat panel display technologies.
Due to the active light-emitting property of OLEDs, backlight is not required such that transparent display can be achieved. A transparent OLED display, with advantages of self-illumination and penetration of ambient light through the display screen, becomes a novel display technology in the future. However, in an existing transparent OLED device, both the anode and the cathode of the OLED device are prepared by using a transparent conductive layer. This results in the following defects:
1) inconsistent luminance of two light-emitting surfaces; and
2) incapable of individually adjusting the luminance of the two light-emitting surfaces.
SUMMARYTechnical ProblemsTechnical problems to be solved by the present invention are to provide a transparent OLED device that can individually adjust light-emitting of two light-emitting surfaces and make the luminance of the two light-emitting surfaces consistent, and a display device that employs the transparent OLED device.
Solution to the ProblemsTo solve the aforementioned problems, the present invention provides a transparent OLED device including a plurality of pixels, each pixel including an organic functional layer, a first transparent electrode and a second transparent electrode being disposed on both sides of the organic functional layer respectively, a reflective electrode being disposed on one side of the organic functional layer, the area of the reflective electrode being less than that of the organic functional layer.
Further, the reflective electrode is located between the first transparent electrode and the organic functional layer, and an insulating layer is disposed between the reflective electrode and the first transparent electrode.
Further, the area of the reflective electrode is 10% to 50% of the area of the organic functional layer.
Further, reflective electrodes between adjacent pixels in one direction are electrically connected, and the reflective electrodes are led out from pixels located at both ends and connected to a power supply.
Further, the reflective electrode is located on the same side as the first transparent electrode, and is disposed in parallel to the first transparent electrode; and a slit is formed between the reflective electrode and the first transparent electrode. Further, insulating material is filled in the slit.
Further, the second transparent electrode is divided into two portions, with one portion being disposed opposite to the reflective electrode and the other portion being disposed opposite to the first transparent electrode.
Further, the first transparent electrode is an anode, and the second transparent electrode is a cathode; or the first transparent electrode is a cathode, and second transparent electrode is an anode.
Further, the average light transmittance the first transparent electrode at a visible wavelength is 50% to 95%; and the average light transmittance of the second transparent electrode at a visible wavelength is 5% to 95%.
The present invention also provides an organic light-emitting display device including the aforementioned transparent OLED device.
The present invention achieves the following beneficial effects:
With regard to the transparent OLED device, by providing a reflective electrode, a light-emitting device over a micro-domain is combined with a transparent light-emitting device, such that the luminance on both sides of a transparent OLED device can be respectively adjusted to be the same or different as required. The present invention can be applied to the field of transparent illumination or display.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a schematic structural view of a transparent OLED device according to one embodiment of the present invention;
FIG. 2 is a schematic planar structural view illustrating connection of a plurality of pixels according to the present invention; and
FIG. 3 is a schematic structural view of a transparent OLED device according to another embodiment of the present invention.
DETAILED DESCRIPTIONIn order to make those skilled in the art better understand and practice the present invention, the present invention will be further described hereinafter in detail with reference to the accompanying drawings and specific embodiments, but the embodiments exemplified hereinafter are not intended to limit the present invention.
As shown inFIG. 1, in this embodiment, a transparent OLED device includes a plurality of pixels. The size of each pixel is not limited. However, generally, the size of a pixel should be less than the minimum resolution of human eyes having a corresponding distance from the screen. Each pixel includes an organicfunctional layer5. The organicfunctional layer5, which is the same as an organic functional layer in the existing technique, includes a hole injection layer, an organic light-emitting layer, an electron injection layer and the like, and will not be described repeatedly here. A first transparent electrode4 and a secondtransparent electrode6 are disposed on both sides of the organicfunctional layer5 respectively, wherein a substrate1 is on the outer side of the first transparent electrode4. Areflective electrode2 is disposed on one side of the organicfunctional layer5, and the area of thereflective electrode2 is less than that of the organicfunctional layer5. In this embodiment, thereflective electrode2 is located between the first transparent electrode4 and the organicfunctional layer5, and an insulating layer3 is disposed between thereflective electrode2 and the first transparent electrode4 in order to prevent a short circuit between the two.
When the transparent OLED device of the present invention is in use, by powering on thereflective electrode2 and the secondtransparent electrode6, the transparent OLED device may be controlled to emit light towards the secondtransparent electrode6; and by powering on the first transparent electrode4 and the secondtransparent electrode6, the double-sided light-emitting or display of the transparent OLED device may be achieved. In addition, if thereflective electrode2, the first transparent electrode4 and the secondtransparent electrode6 are powered on simultaneously, but are subjected to a different current or voltage, it is possible to adjust the double-sided light-emitting luminance. In addition, by setting the color of an organic functional layer corresponding to thereflective electrode2 in a different color from that of an organic functional layer corresponding to the first transparent electrode4, the display color may be adjusted by thereflective electrode2.
In the present invention, the area of the reflective electrode is preferably 10% to 50% of the area of the organic functional layer. The effect of adjustment will not be significant when the area of the reflective electrode is too small, while the transparency of the OLED device will be influenced when the area of the reflective electrode is too large.
Manufacture of the transparent OLED device of this embodiment includes the following steps:
preparing a first transparent electrode4 on a transparent substrate1;
preparing a reflective electrode layer on the first transparent electrode4;
etching a portion of the reflective electrode layer by processes such as coating, exposing, developing and etching, with the remaining portion forming areflective electrode2;
etching an edge of thereflective electrode2, such that a portion of thereflective electrode2 connected to the first transparent electrode4 is disconnected;
filling the part where thereflective electrode2 is disconnected from the first transparent electrode4 with an insulating material to form an insulating layer3;
evaporating an organicfunctional layer5 over the first transparent electrode4 and thereflective electrode2; and
preparing a secondtransparent electrode6 over the organicfunctional layer5 to obtain a transparent OLED device of this embodiment.
Nevertheless, what is described above is only a preferred scheme for manufacturing a transparent OLED device of this embodiment, and the actual manufacturing process is not limited thereto.
In this embodiment, since thereflective electrode2 is disposed between the first transparent electrode4 and the secondtransparent electrode6, to connect thereflective electrode2 of each pixel to the power supply, thereflective electrodes2 between adjacent pixels in one direction may be electrically connected, and the serially-connectedreflective electrodes2 are led out from pixels at both ends and connected to the power supply. As in the embodiment shown inFIG. 2, in this embodiment, thereflective electrodes2 between pixels of each row in the longitudinal direction, i.e., in a same row, are connected in series, and are led out from pixels at both extreme ends to form a reflective lead-out electrode7, and the reflective lead-out electrode7 is connected to an external power supply to supply power to thereflective electrode2. Since the area of the first transparent electrode4 in this embodiment completely covers the organicfunctional layer5 of a pixel, the first transparent electrodes4 between pixels in a same row may be connected in series and then led out from both ends to form a first transparent lead-out electrode8 in the same manner as the reflective electrode; or, the first transparent electrodes4 of all pixels may be electrically connected and then led out from the surrounding.
As in another embodiment of the transparent OLED device of the present invention shown inFIG. 3, in this embodiment, thereflective electrode2 is located on a same side as the first transparent electrode4, and is disposed in parallel to the first transparent electrode4. To prevent a short circuit between thereflective electrode2 and the first transparent electrode4, aslit9 may be formed between thereflective electrode2 and the first transparent electrode4. Further preferably, an insulating material may be filled in theslit9 to enhance the insulating property. However, the secondtransparent electrode6 in this embodiment is divided into two portions, with one portion being disposed opposite to thereflective electrode2 and the other portion being disposed opposite to the first transparent electrode4. To achieve the insulating effect, a slit is also formed between the two portions of the secondtransparent electrode6. Furthermore, insulating material may be also filled in the slit. Of course, in other embodiments, the secondtransparent electrode6 may be an entirety which completely covers the organicfunctional layer5.
In the above-mentioned embodiments, the first transparent electrode4 and the secondtransparent electrode6 are a cathode and an anode of an OLED device respectively, and may be exchangeable in position. That is, the first transparent electrode4 may be an anode and the secondtransparent electrode6 may be a cathode; or, the first transparent electrode4 may be a cathode and the secondtransparent electrode6 may be an anode, without imposing any influence on the implementation of the present invention. The average light transmittance of the first transparent electrode4 at a visible wavelength is 5% to 95%; and the average light transmittance of the second transparent electrode at a visible wavelength is 5% to 95%. When the average light transmittance of the secondtransparent electrode6 at a visible wavelength is 5% to 50%, a large portion of light emitted by the OLED device is output from the side of the first transparent electrode4, and a small portion thereof is output from the side of the secondtransparent electrode6, thereby forming a double-sided display. Light emitted by the OLED device may be output from both sides, thereby forming a transparent OLED device.
The aforementioned embodiments are only preferred embodiments merely used for describing the present invention in detail, and the protection scope of the present invention is not limited thereto. For a person skilled in the art, various replacements or improvements may be made on the basis of the present invention, and those replacements or improvements shall be regarded as falling into the protection scope of the present invention. The protection scope of the present invention is subject to the appended claims.