Patent Application
20080174531
This Non-provisional application claims priority under 35 U.S.C. ยง119(a) on Patent Application No(s). 096102399 filed in Taiwan, Republic of China on Jan. 22, 2007, the entire contents of which are hereby incorporated by reference.
1. Field of Invention
The invention relates to a display apparatus and a manufacturing method thereof. More particularly, the invention relates to an electronic paper display apparatus and a manufacturing method thereof.
2. Related Art
In the information era, the demands of users for communicating with information sources are increasing. Therefore, the display apparatus that can broadcast information has become one of the indispensable electronic products in modern life. The display apparatus has evolved from the cathode ray tube (CRT) display to the modern liquid crystal display (LCD) that is thinner and lighter. Accordingly, the LCD has been widely used in communications, information and consumer electronics. However, the LCD has to be continuously powered in order to operate. Therefore, the display technology of electrophoretic display (EPD) with lower power consumption has been invented.
Now, computers are often used to process and store large amount of data. However, the volume, weight and operation of computer are not as convenient in carrying and reading as what of printed information on paper. To enjoy the portability and convenience in reading of paper while having the capabilities to process data and be environmentally friendly, electronic paper using the EPD is disclosed.
As shown in
When a potential difference is applied between the pixel electrode layer 111 and the transparent electrode layer 124, the electrically charged particles C1 move toward the pixel electrode layer 111 or the transparent electrode layer 124, which carries charges with the polarity opposite to those of the electrically charged particles. Therefore, by selectively applying a voltage between the two electrode layers 111 and 124, the color of the dielectric solvent L1 or the electrically charged particles C1 can be determined. Then, the displayed color is changed by applying a reverse voltage.
As shown in
However, the conventional approach of achieving the full-color display is to precisely arrange the separated electrophoretic materials 122 and align the color filters 13 on the cover plate 14 with the pixel electrode layer 111 of the driving substrate 11. Therefore, the complexity of the manufacturing process is increased. In addition, the proper aligning apparatus and technique have to be correspondingly provided, and the manufacturing cost of the electronic paper apparatus 1 is also increased.
Therefore, it is an important subject to provide an electronic paper apparatus and a manufacturing method thereof, which have the full-color displaying effect and may be manufactured with simplified steps and lowered cost.
In view of the foregoing, the invention is to provide an electronic paper apparatus and a manufacturing method thereof, which have the full-color displaying effect and may be manufactured with simplified steps and lowered cost.
To achieve the above, the invention discloses an electronic paper apparatus including a driving substrate, an electronic paper and an optical modulation layer. The electronic paper includes an electrophoretic material and a transparent electrode layer disposed opposite to the driving substrate. The optical modulation layer is disposed on the electronic paper.
In addition, the invention also discloses a manufacturing method of an electronic paper apparatus. The method includes the steps of: disposing an electronic paper over a driving substrate, wherein the electronic paper includes an electrophoretic material and a transparent electrode layer, and the transparent electrode layer is disposed opposite to the driving substrate; and ink jetting or printing an optical modulation layer on the electronic paper.
As mentioned above, the optical modulation layer of the electronic paper apparatus in the invention is disposed on the electronic paper and disposed over the transparent electrode. Compared with the prior art, the optical modulation layer of the invention may be formed on the electronic paper and opposite to the pixel electrode of the driving substrate by way of ink jetting or printing. Thus, the conventional aligning step, which is performed after the optical modulation layer is disposed on the package cover plate, may be omitted. In addition, the complicated processes of arranging the electrophoretic materials for three primary colors to achieve the full-color display may be omitted. Therefore, the manufacturing cost is effectively decreased, and the product yield is increased.
The invention will become more fully understood from the detailed description and accompanying drawings, which are given for illustration only, and thus are not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Referring to
The driving substrate 21 includes a pixel electrode layer 211, which may include a plurality of pixel electrodes 211a. In the embodiment, the driving substrate 21 may be a glass substrate, a plastic substrate, a printed circuit board or a flexible circuit board. The pixel electrodes 211a of the pixel electrode layer 211 are arranged in an array so that the driving substrate 21 is driven by way of active matrix array driving or passive matrix array driving. In the embodiment, the driving substrate 21 is driven by way of active matrix array driving in this example.
The electronic paper 22 is disposed over the driving substrate 21, especially disposed over the pixel electrode layer 211. The electronic paper 22 includes an upper substrate 221, a transparent electrode layer 222, an electrophoretic material 223 and an adhesive layer 224 disposed opposite to the upper substrate 221. The transparent electrode layer 222 is disposed at one side of the upper substrate 221. The electrophoretic material 223 is disposed between the upper substrate 221 and the adhesive layer 224. That is, the electrophoretic material 223 is disposed between the transparent electrode layer 222 and the pixel electrode layer 211. The electrophoretic material 223 includes a plurality of pigment particles C2 and a dielectric solvent L2. The pigment particles C2 are dispersed over the dielectric solvent L2. In the embodiment, the electrophoretic material 223 is accommodated within, for example but not limited to, a microcup structure. Of course, the electrophoretic material 223 may also cover a micro-capsule structure (see
As mentioned above, the transparent electrode layer 222 is disposed corresponding to the pixel electrode layer 211 of the driving substrate 21. Herein, the transparent electrode layer 222 may also be referred to as a common electrode layer. The transparent electrode layer 222 is disposed opposite to the pixel electrodes 211a. So, when a voltage difference is applied between the electrode layers 211 and 222, the pigment particles C2 are driven to reflect light rays on a display surface to present the color of the pigment particles C2 or the dielectric solvent L2. In the embodiment, the material of the transparent electrode layer 222 may be indium tin oxide (ITO), aluminum zinc oxide, indium zinc oxide or cadmium tin oxide.
In addition, the driving substrate 21 of the embodiment may further include a plurality of thin film transistors for driving the pixel electrode layer 211 so that the active electrode driving design is obtained. The thin film transistors may be formed on the driving substrate 21 and arranged in an array by the amorphous silicon (amorphous Si) or low-temperature polysilicon manufacturing process. The thin film transistors are connected to the pixel electrodes 211a to serve as driving switches.
In the embodiment, the optical modulation layer 23 is disposed on the electronic paper 22 and is formed over the transparent electrode layer 222 by way of ink jetting or printing. That is, the optical modulation layer 23 may be formed on the surface of the upper substrate 221 of the electronic paper 22 directly by way of ink jetting or printing on the structure of the conventional electronic paper. The optical modulation layer 23 may include at least one filtering material or at least one color converting material. The filtering material may be selected from at least one of a red filtering material, a blue filtering material and a green filtering material to achieve the fill-color display. The color converting material may include a fluorescent material and/or a phosphorus material so that multiple colors are achieved by mixing, scattering and exciting the passing light. In this embodiment, the optical modulation layer 23 is disposed corresponding to the pixel electrode layer 211. That is, the filtering material or the color converting material in the optical modulation layer 23 is aligned with the pixel electrode 211a on the pixel electrode layer 211.
In order to enhance the connection strength between the optical modulation layer 23 and the upper substrate 221 of the electronic paper 22, a roughing structure (not shown) is formed on the connecting surface between the upper substrate 221 and the optical modulation layer 23. The roughness of the surface structure assists in the material adhering of the optical modulation layer 23. In addition to enhancing the connection strength between the optical modulation layer 23 and the upper substrate 221 by the roughing structure, the electronic paper apparatus 2 may further include an ink-jet auxiliary layer 225 disposed between the optical modulation layer 23 and the upper substrate 221 (i.e., disposed on the connection interface between the optical modulation layer 23 and the upper substrate 221), as shown in
In addition, the electronic paper apparatus 2 of the embodiment may further include a barrier layer 231, which is formed over the upper substrate 221 (i.e., disposed on the connection surface between the upper substrate 221 and the optical modulation layer 23) by way of ink jetting or printing. The barrier layer 231 may be a black matrix layer which defines a plurality of filtering areas F. The filtering material or the color converting material of the optical modulation layer 23 is disposed in the filtering areas F. The provision of the barrier layer 231 prevents the materials of the optical modulation layer 23 between the filtering areas F from producing the alternately mixed phenomenon.
Referring to
Referring to
With reference to
The step of disposing the electronic paper 22 over the driving substrate 21 will be described in detail in the following. First, an adhesive layer 224 is disposed over the driving substrate 21. Of course, the adhesive layer 224 may also be disposed on the surface of the electronic paper 22. Next, the electronic paper 22 is adhered to the driving substrate 21. The electronic paper 22 further includes an upper substrate 221, the transparent electrode layer 222 is disposed at one side of the upper substrate 221, and the transparent electrode layer 222 is disposed between the upper substrate 221 and the driving substrate 21.
In the step S2, the optical modulation layer 23 is formed on the electronic paper 22 by way of ink jetting or printing. More particularly, the optical modulation layer 23 is disposed on the upper substrate 221. Before this step S2, the manufacturing method of the electronic paper apparatus 2 may further include a step of aligning an ink jetting apparatus or a printing apparatus with the driving substrate 21 so as to define the position of the optical modulation layer 23. Herein, the driving substrate 21 may be formed with at least one positioning mark to facilitate the positioning between the ink jetting apparatus or the printing apparatus and the driving substrate 21. Thus, the arranging position of the optical modulation layer 23 can be defined so that the optical modulation layer 23 can be aligned with the pixel electrode layer 211 of the driving substrate 21.
In addition, the manufacturing method may further include, before the step S2, a step of forming a roughing structure on the surface of the upper substrate 221. The surface is a surface of the upper substrate 221 on which the optical modulation layer 23 is disposed. The roughing structure can enhance the connection strength between the upper substrate 221 and the optical modulation layer 23. In addition the manufacturing method may further include the step of disposing an ink-jet auxiliary layer 225 between the optical modulation layer 23 and the upper substrate 221. That is, the ink-jet auxiliary layer 225 is firstly formed on the upper substrate 221 to assist in the material adhering of the subsequent optical modulation layer 23 so that the better connection strength is obtained. The material of the ink-jet auxiliary layer 225 may be glue, for example.
In addition, the manufacturing method of this embodiment may further include the step of disposing a barrier layer 231 on the surface of the upper substrate 221 by way of ink jetting or printing. That is, the barrier layer 231 is formed on the surface of the upper substrate 221, on which the optical modulation layer 23 is to be formed. More particularly, a black matrix layer may be formed to serve as the barrier layer 231 for defining a plurality of filtering areas F, in which the optical modulation layer 23 to be aligned with the pixel electrode 211a is disposed. The barrier layer 231 can effectively prevent the material of the optical modulation layer 23 from mixing alternately.
In order to achieve the optimum operation state of the electronic paper apparatus 2, the manufacturing method of this embodiment further includes the step of providing a package structure 24 connected to the driving substrate 21 to from a closed space S for accommodating the electronic paper 22 and the optical modulation layer 23 and to prevent the external moisture and oxygen from entering the space, as shown in
In summary, the optical modulation layer of the electronic paper apparatus in the invention is disposed on the electronic paper and disposed over the transparent electrode. Compared with the prior art, the optical modulation layer of the invention may be formed on the electronic paper and opposite to the pixel electrode of the driving substrate by way of ink jetting or printing. Thus, the conventional aligning step, which is performed after the optical modulation layer is disposed on the package cover plate may be omitted. In addition, the complicated processes of arranging the electrophoretic materials for three primary colors to achieve the full-color display may be omitted. Therefore, the manufacturing cost can be effectively decreased, and the product yield can be increased.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 096102399 | Jan 2007 | TW | national |
