1. Field of the Invention
The present invention is related to a liquid crystal display device and a manufacturing method for the same, and more particularly, to a liquid crystal display device and a manufacturing method thereof that use different alignment materials to provide alignment films on the top substrate and the bottom substrate. Due to the different influences of different alignment materials for liquid crystals, liquid crystal cells have multiple alignment domains formed therein.
2. Description of Related Art
Multi-domain techniques used to control alignment directions of liquid crystals have been extensively applied in liquid crystal display (LCD) devices. For example, the multi-domain techniques can be applied to manufacture transflective LCD devices, widen the viewing angle of common LCD devices, and increase the reflective spectrum or viewing angle of cholesteric liquid crystal devices. Generally, photo alignment, protrusions and fringe electric field are often used to form multiple alignment domains of liquid crystals.
First, two examples of using the photo alignment technique to manufacture transflective LCD devices are given as follows. Reference is made to
Next, an example for using the protrusions to widen the viewing angle of LCD devices is given as follows. Reference is made to
Lastly, an example of using protrusions together with fringe electric fields provided via pixel electrodes to widen the viewing angle of LCD devices is given as follows. Reference is made to
However, the conventional LCD devices mentioned above still have some drawbacks in cost and manufacturing procedures. In the case of using the photo alignment technique, additional optical masks and ultraviolet light are needed in the manufacturing procedure. Moreover, the photo alignment technique is not easy to use in the manufacture of large-sized LCD devices. In addition, in the case of using the protrusion technique, additional manufacturing steps are required and the protrusions must be formed precisely. Lastly, in the case of using electric fields to control the alignment directions of liquid crystals, the patterned electrodes is required, the improvement on widening the viewing angle is limited, and a large driving voltage is needed.
The objective of the present invention is to provide a liquid crystal display (LCD) device and a manufacturing method for the same. The present invention uses different alignment materials to form the alignment films on the substrates. Due to different properties of the alignment films, multiple liquid crystal domains with different alignment arrangements are provided. In this way, the cost is reduced and the manufacturing procedure is simplified.
For achieving the objective above, the present invention provides a LCD device, including a top substrate, a bottom substrate, an upper alignment film, a lower alignment film, and a liquid crystal layer between the top and bottom substrate. The LCD device can further include a top electrode layer, a bottom electrode layer and a color filter.
It should be noted that the alignment films are formed by providing different alignment materials on the substrates. Due to different properties of the alignment films, multiple liquid crystal domains with different alignment orientation are provided. When liquid crystals contact the different alignment films, they are aligned in different orientations. The upper or lower alignment film is made of at least two different alignment materials. The alignment materials that are capable of making liquid crystals aligned in different orientation or pre-tilt angle can be obtained by mixing the vertical and horizontal alignment materials with a different ratio. After a phase separation process is performed, the mixture of the alignment materials can align liquid crystals with a pre-tilt angle that ranges between 0° to 90°, depending on the mixing ratio.
Several methods could be implemented to form different alignment materials on the corresponding regions of substrates, and it becomes a patterned alignment layer. For example, the patterned alignment layers are formed by filling different alignment materials to a patterned substrate defined by multiple separating walls or by surface treatment on the substrates. Moreover, the different alignment materials can also be filled directly on the corresponding regions of the substrates.
The alignment orientations of multiple liquid crystal domains make the LCD device of the present invention have a property of wide viewing angle. Furthermore, when this structure is applied to the cholesteric liquid crystal display, it will have the properties of wide viewing angle and broad reflective spectrum. In addition, this multi domain structure could be applied to form a transflective LCD. In such display device, the bottom substrate further includes multiple reflective regions with reflectors and transmissive regions not covered by the reflectors, where the two types of regions are filled with different alignment materials. The reflective regions are filled with the vertical alignment material and the transmissive regions are filled with horizontal alignment material. The upper alignment film of the top substrate is filled with the horizontal alignment material.
For achieving the objective above, the present invention provides a method for manufacturing a LCD device, including providing a top substrate and a bottom substrate; providing different alignment materials on the corresponding regions of the substrates; and filling liquid crystals between the top and bottom substrate.
Numerous additional features, benefits and details of the present invention are described in the detailed description, which follows.
The foregoing aspects and many of the attendant advantages of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
Reference is made to
For such transflective LCD, two different alignment materials are provided to form the upper alignment film 511 or the lower alignment film 521 (in this embodiment, only the lower alignment film 521 is formed by using two different alignment materials). Thus, the corresponding two different domains 53a and 53d are formed thereby. When the liquid crystals contact these two different alignment materials, different alignment orientations are formed. In
In order to provide different alignment materials on the top substrate 51 or the bottom substrate 52, multiple separating walls 54 are disposed on the substrates (
Reference is made to
In practice, except for using the ink-jet printing process, the flexography and the molding processes can also be used to dispose the alignment film.
The transflective display device 50 further includes a top electrode layer, a bottom electrode layer and a color filter (not shown). The top electrode layer can be disposed between the top substrate 51 and the upper alignment film 511 while the bottom electrode layer can be disposed between the bottom substrate 52 and the lower alignment film 521. The color filter can be disposed on the top substrate 51 or the bottom substrate 52 to make the color transflective display device 50.
Reference is made to
In step S804, different alignment materials are provided on the patterned structure of the top substrate 51 or the bottom substrate 52. The upper alignment film 511 and the lower alignment film 521 are provided by using an ink-jet printing process, the flexography or the molding process Lastly, liquid crystals are filled between the top substrate 51 and the bottom substrate 52 to form the liquid crystal layer 53 (step S806).
The manufacturing process of the LCD device 50 can further include following steps. A reflective plate is provided on the bottom substrate 52 to form a reflective region R. The region of the bottom substrate 52 not covered by the reflective plate forms a transmissive region T. A top electrode layer is provided on the top substrate 51 while a bottom electrode layer is provided on the bottom substrate 52. A color filter is provided on the top substrate 51 or the bottom substrate 52.
In the present invention, multiple liquid crystal domains are formed by using different alignment materials on the top and bottom substrate. Large-sized display devices with multiple liquid crystal domains can be made easily by using such technique. The different alignment materials can be provided on the corresponding regions via a simple process such as ink-jet printing. Compared with the photo alignment technique, the ink-jet printing is cheaper and much simpler. Hence, the cost is reduced and the manufacturing procedure is simplified.
Although the present invention has been described with reference to the preferred embodiments thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are embraced within the scope of the invention as defined in the appended claims.
Number | Date | Country | Kind |
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94120607 | Jun 2005 | TW | national |