The present application claims the benefit of Chinese Patent Application No. 201810241784.5 filed with the Chinese Patent Office on Mar. 22, 2018, the entire disclosure of which is incorporated herein by reference.
The present disclosure relates to the field of display technologies, and specifically to a display panel and a method for manufacturing the display panel.
Liquid crystal display devices have been widely used in people's daily work and life. With the development of display technologies, users' requirements on liquid crystal display devices also increase accordingly. For example, a faster response speed is desired in case of image switching. For an existing liquid crystal display device, the response speed upon image display still needs to be improved.
According to an aspect of the present disclosure, there is provided a display panel comprising: an array substrate; a color film substrate assembled with the array substrate; and liquid crystal molecules sealed between the array substrate and the color film substrate. The array substrate comprises a pixel electrode and a common electrode, orthographic projections of the pixel electrode and the common electrode on a base substrate of the array substrate comprises an overlapping region, and an azimuth angle of the liquid crystal molecules is 90 degree.
In some embodiments, the base substrate of the array substrate comprises a plurality of sub-pixel regions arranged in an array, the common electrode comprises a plurality of electrode blocks, and each of the plurality of sub-pixel regions is provided with one pixel electrode and at least two electrode blocks.
In some embodiments, the pixel electrode is a plate-like electrode, the electrode block is a strip electrode, and orthographic projections of the at least two electrode blocks on the base substrate are located at edges of the sub-pixel region and fall within an orthographic projection of the pixel electrode on the base substrate.
In some embodiments, t the base substrate of the array substrate comprises a plurality of sub-pixel regions arranged in an array, the common electrode comprises a plurality of electrode blocks, each of the sub-pixel regions is provided with one pixel electrode and one electrode block, and each electrode block comprises at least one hollow portion.
In some embodiments, outer edges of orthographic projections of portions other than the hollow portion of each electrode block on the base substrate are located at edges of the sub-pixel region and fall within an orthographic projection of the pixel electrode on the base substrate.
In some embodiments, the common electrode and the pixel electrode are on a same side of the base substrate of the array substrate.
In some embodiments, the common electrode and the pixel electrode are located on a side of the base substrate facing the liquid crystal molecules, the pixel electrode is closer to the base substrate than the common electrode, and an insulating planarization layer is arranged between the common electrode and the pixel electrode.
In some embodiments, a pretilt angle of the liquid crystal molecules is in a range of 85 to 90 degree.
Another embodiment of the present disclosure provides a display device comprising the display panel according to any one of the foregoing embodiments.
A further embodiment of the present disclosure provides a method for manufacturing a display panel, comprising: providing a color film substrate and an array substrate, the array substrate comprising a pixel electrode and a common electrode; and assembling the array substrate with the color film substrate and filling liquid crystal molecules between the array substrate and the color film substrate. An azimuth angle of liquid crystal molecules is 90 degree.
In some embodiments, a pretilt angle of the liquid crystal molecules is in a range of 85 to 90 degree.
The above and/or additional aspects and advantages of the present disclosure will become apparent and easily understood from the description of embodiments in conjunction with the following drawings in which:
Hereinafter, embodiments of the present disclosure will be described in detail. Examples of the embodiments are shown in the accompanying drawings, and the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout the specification. The embodiments described below with reference to the drawings are exemplary, which are only used to explain the present disclosure, and should not be construed as limiting the scope of the present application.
In the description of the disclosure, the orientations or positional relationships indicated by the terms such as “above” or “upper”, “lower” or “below”, and the like are based on the orientations or positional relationships shown in the drawings, which are merely for the convenience of describing the exemplary embodiments of the present disclosure rather than requiring the embodiments of the present disclosure to be constructed and implanted in a particular orientation, and therefore cannot be construed as limiting the scope of the present application.
In an aspect of the present disclosure, a display panel is proposed. According to an embodiment of the present disclosure, referring to
Referring to
Referring to
For the liquid crystal display panel shown in the embodiment of
The inventors of the application have found that, for a liquid crystal display panel having such common electrodes and pixel electrodes, the response speed upon image switching is still slow. In this regard, the inventors of the present application have realized through research that this is largely caused by the manner in which liquid crystal molecules in the display panel are deflected. The liquid crystal molecules in the display panel usually transfer from an initial state (e.g., a state of being arranged in the horizontal direction) when the liquid crystal molecules are arranged parallel to a rubbing direction for the alignment film to another state, and time required for such transition may take about 15 ms.
In other words, the response time of liquid crystal molecules when they are deflected under the effect of an electric field is relatively long, which is an important factor causing the slow response speed when a display device displays an image. The inventors of the present application tried to improve the response speed of the liquid crystal molecules by adjusting the shapes of the electrodes, the spacing between the electrodes, the arrangement of the liquid crystal molecules, etc. while keeping the electrode structure (that is, the relative position between the common electrode 120 and the pixel electrode 110) in the display panel as shown in
According to the embodiment of the present disclosure, the liquid crystal molecules have an azimuth angle of 90 degree, thereby enabling the liquid crystals to have faster response speed. Herein, the “azimuth angle” mentioned and the “pretilt angle” mentioned below are parameters for describing an initial state of the liquid crystal. That is, the initial state of the liquid crystal molecules in space can be determined using these two angles. In general, the pretilt angle of a liquid crystal molecule refers to a tilt angle of the long axis direction of the liquid crystal molecule in the initial state with respect to the plane of the liquid crystal display panel (base substrate), and the azimuth angle of the liquid crystal molecule reflects an angle between the long axis direction of the liquid crystal molecules in the initial state and the rubbing direction for the alignment film.
The meanings of the azimuth angle and the pretilt angle of the liquid crystal molecule will be illustrated below with reference to
In the example of
The inventors of the present application have researched and recognized basic elastic constants and related performance parameters of liquid crystal molecules in a liquid crystal display panel in different operation modes. As shown in Table 1, the basic elastic constants of liquid crystals comprise a splaying elastic constant K11, a torsional elastic constant K22 and a bending elastic constant K33, K33>K11>K22. When the liquid crystals are in an operation mode of “vertical rotation”, the elastic constant K33 thereof is larger than the elastic constant in other operation modes. The “vertical rotation” mentioned here means that the liquid crystal molecules start to rotate from an initial vertical state, that is, the azimuth angle of the liquid crystal molecules is 90 degree. “Horizontal rotation” means that the liquid crystal molecules start to rotate from an initial horizontal state (the azimuth angle is 0 degree). Since the basic elastic constant K33 is relatively larger, time required for the liquid crystal molecules to perform vertical rotation is shorter. Accordingly, the response time for the liquid crystal display panel to perform image display is also shortened, so that the display device exhibits a faster response speed when displaying an image, achieving a better image switching effect.
According to some embodiments of the disclosure, the base substrate of the array substrate 100 comprises a plurality of sub-pixel regions arranged in an array (a single sub-pixel region is shown, for example, as a region surrounded by a dotted line in
According to other embodiments of the disclosure, the common electrode comprises a plurality of electrode blocks, each of the sub-pixel regions is provided with one pixel electrode and one electrode block, and each electrode block has at least one hollow portion. That is, in this example, the electrode blocks of the common electrode are in one-to-one correspondence with the sub-pixel regions. Taking the partial sectional view of the display panel shown in
According to an embodiment of the present disclosure, the common electrode 120 and the pixel electrode 110 may be disposed on the same side of the substrate 100. According to the embodiment shown in
According to an embodiment of the present disclosure, the width (L2 as shown in
In addition, the inventors of the present application have found that, for the liquid crystal display panels provided in the foregoing embodiments, the pretilt angle of the liquid crystal molecules also has a certain effect on the performance (including the response speed) of the liquid crystal display device. For example, the pretilt angle of the liquid crystal molecules would affect the transmittance of the display panel in a dark state, the driving voltage for driving the liquid crystal molecules to be deflected, and the response speed of the liquid crystal molecules. In the case where the pretilt angle of the liquid crystal molecules is too small (for example, less than 45 degree), the light transmittance of the liquid crystal display panel in a dark state is high, and even light leakage occurs. However, a small pretilt angle is advantageous for improving the response speed of the liquid crystal molecules. In order to balance the light leakage problem of the liquid crystal display panel in a dark state and the response speed of the liquid crystal molecules, in some embodiments, the liquid crystal molecules have a pretilt angle of 85-90 degree. As an example, when the liquid crystal molecules have a pretilt angle of 87 degree and an azimuth angle of 90 degree, a faster response speed of the display panel can be achieved and the light leakage phenomenon of the liquid crystal display panel in a dark state can be mitigated.
In another aspect of the present disclosure, the present disclosure proposes a method for manufacturing a display panel. According to an embodiment of the disclosure, the method for manufacturing a display panel comprises the following steps:
S100: providing a color film substrate and an array substrate. According to an embodiment of the disclosure, in this step, an array substrate provided with a pixel electrode and a common electrode, and a color film substrate may be provided. The array substrate may have the same structure as the array substrate in the display panel described above, and details are not described here again. The specific structure of the color film substrate is not particularly limited, and those skilled in the art can make selection as needed.
S200: assembling the array substrate with the color film substrate and filling liquid crystal molecules therein. According to an embodiment of the present disclosure, in this step, the array substrate is assembled with the color film substrate and liquid crystal molecules are filled therein. The liquid crystal molecules have an azimuth angle of 90 degree. As a result, the manufactured display panel can have a faster response speed and is applicable to scenarios that require fast and frequent image switching. For specific principles, reference may be made to the foregoing embodiments of the display panel, and details will not be repeated here.
In the following, fitting tests are performed on the response time of a display device having the above-described display panel according to an embodiment of the present disclosure.
In several examples of simulation tests, the electrode structure in the display panel is shown in
Tests are performed on Tr time and Tf time (Tr is the time required for a screen brightness to rise from 10% to 90%, and Tf is the time required for the screen brightness to decrease from 90% to 10%) in two liquid crystal arrangement modes described above. Details are shown in Table 2 below.
It can be seen that when the azimuth angle of the liquid crystal molecules is 90 degree (e.g., vertical arrangement with respect to the rubbing direction of the alignment film), the response speed is notably faster than that in the circumstance where the azimuth angle of the liquid crystal molecules is 0 degree (e.g., horizontal arrangement). As shown in Table 2, the response time RT (Tr+Tf) in the vertical arrangement mode is 3.3 ms, and the response time in the horizontal arrangement mode is 26 ms.
In the present description, the description with reference to the terms “an embodiment”, “another embodiment”, and the like means that specific features, structures, materials or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present disclosure. In this specification, the schematic description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, without causing any contradiction, those skilled in the art may combine different embodiments or examples and features of the different embodiments or examples described in this specification.
Although some embodiments of the present disclosure have been illustrated and described above, it can be understood that the above-described embodiments are exemplary and should not be construed as limiting the present disclosure. A person having an ordinary skill in the art can make variations, amendments, replacements and modifications to the above-described embodiments within the scope of the disclosure. These variations, amendments, replacements and modifications all fall within the scope of the present application.
Number | Date | Country | Kind |
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201810241784.5 | Mar 2018 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2019/078995 | 3/21/2019 | WO | 00 |