Patent Application
20180143492
This application claims the benefit of People's Republic of China application Serial No. 201611024645.4, filed Nov. 21, 2016, the subject matter of which is incorporated herein by reference.
The disclosure relates in general to a display device, and more particularly to a liquid crystal display device.
In response to people's pursuit of high brightness and high color of the visual screen, the technology of color display is developed and used. The display is used in many fields of people's daily life such as advertising billboard, TV, and car navigation. However, the development of various types of display screens including the cathode ray tube (CRT) screen to the plasma screen, the liquid crystal screen, and the organic light emitting diode (OLED) screens all encounter similar problems.
Therefore, how to provide a display panel having excellent display quality and technology competitiveness has become a prominent task for the industries.
The present disclosure is directed to a display device. According to the display device of an embodiment of the present disclosure, a blue light emitted from a backlight module excites the quantum dots in each color region of the color converting layer to generate a light. The color converting layer doped with quantum dots is a self-luminous color converting layer of which the luminous efficiency at least is above 70-90%, and therefore the overall luminous efficiency of the display device is increased.
According to one embodiment of the present disclosure, a display device is provided. The display device includes a first substrate, a second substrate, a display medium, a color converting layer and a backlight module. The display medium is disposed between the first substrate and the second substrate, and includes blue phase liquid crystal (BP-LC), polymer dispersed liquid crystal (PD-LC), self-assembled liquid crystal (SA-LC), dye doped nematic liquid crystal, dye doped cholesteric liquid crystal, dye doped blue phase liquid crystal, dye dispersed liquid crystal or dye doped self-assembled liquid crystal. The color converting layer is disposed between the display medium and the second substrate, and includes multiple quantum dots. The first substrate is disposed between the backlight module and the display medium.
According to another embodiment of the present disclosure, a display device is provided. The display device includes a first substrate, a second substrate, a display medium, a color converting layer, a backlight module, a first polarizer, a second polarizer and a backlight module. The display medium is disposed between the first substrate and the second substrate, and includes dye doped liquid crystal. The color converting layer is disposed between the display medium and the second substrate, and includes multiple quantum dots. The first substrate is disposed between the backlight module and the display medium. The first polarizer is disposed between the first substrate and the backlight module. The first alignment layer is disposed between the first substrate and the display medium.
According to a further embodiment of the present disclosure, a display device is provided. The display device includes a first substrate, a second substrate, a display medium, a color converting layer, a first polarizer, a second polarizer and a backlight module. The display medium is disposed between the first substrate and the second substrate, and the display medium includes optically isotropic liquid crystal. The first polarizer is disposed between the first substrate and the backlight module. The second polarizer is disposed between the second substrate and the display medium. The first polarizer is disposed between the first substrate and the backlight module.
The above and other aspects of the disclosure will become better understood with regard to the following detailed description of the preferred but non-limiting embodiment(s). The following description is made with reference to the accompanying drawings.
According to the display device of an embodiment of the present disclosure, a blue light emitted from a backlight module excites the quantum dots in each color region of the color converting layer to generate a light. The color converting layer doped with quantum dots is a self-luminous color converting layer of which the luminous efficiency at least is above 70-90%, and therefore the overall luminous efficiency of the display device is increased. Detailed descriptions of the embodiments of the present disclosure are made with reference to accompanying drawings. Designations common to the accompanying drawings and embodiments are used to indicate identical or similar elements. It should be noted that the accompanying drawings are simplified such that the embodiments can be more clearly described. Technical structures disclosed in the embodiments are for explanatory and exemplary purposes only, not for limiting the scope of protection of the present disclosure. Any person ordinary skilled in the technology of the present disclosure can make suitable modifications or variations to the structures according to the needs in actual implementations.
In some embodiments, the display medium 300 includes blue phase liquid crystal (BP-LC), polymer dispersed liquid crystal (PD-LC), self-assembled liquid crystal (SA-LC), dye doped nematic liquid crystal, dye doped cholesteric liquid crystal, dye doped blue phase liquid crystal, dye doped polymer dispersed liquid crystal or dye doped self-assembled liquid crystal, and the display medium 300 may be formed of any one of the above or any combination thereof. Any liquid crystals conformed with the characteristics may be used as the display medium, but the present disclosure is not limited thereto. In some embodiments, the backlight module 500 may be a blue backlight module.
In an embodiment, the color converting layer 400 may include a red region 400R, a green region 400G and a blue region 400B. In an embodiment of the present disclosure, the color converting layer 400 is doped with quantum dots. Therefore, with the design of the quantum dots, a blue light emitted from the backlight module 500 excites the quantum dots in each color region of the color converting layer 400 to generate a light. That is, the color converting layer 400 doped with quantum dots is a self-luminous color converting layer. In some embodiments, since the backlight module 500 emits the blue light, the blue region 400B may be formed of a transparent material or may be disposed without any filers. The transparent material may be an insulation layer, such as silicon nitride (SiNx) or silicon oxide (SiOx). Or, the blue region 400B may be formed of a highly light-transmitting organic glue such as acrylic glue or epoxy glue, but the present disclosure is not limited thereto. Moreover, the blue region 400B not doped with quantum dots can also be used.
In comparison to a conventional display device, which adopts a white light backlight source, when the white light passes through an RGB color filter, the light of undesired colors is absorbed by the color filter, only the light of predetermined colors can pass through the RGB color filter and illuminate, and thus a penetration rate of only about 33% is achieved. In contrast, according to the embodiments of the present disclosure, the display device uses the blue light emitted from the backlight module 500 to excite the quantum dots in each color region of the color converting layer 400 to generate a light, and thus a luminous efficiency at least above 70-90% can be achieved, such that the overall luminous efficiency of the display device can be increased.
In some embodiments as indicated in
Dye doped in liquid crystal can absorb lights, and the arrangement of dye molecules can be changed by applying a voltage. When the dye molecules are arranged in a direction perpendicular to the incident direction of the light (that is, the dye molecules basically lay flat along a direction parallel to the substrate surface), the light passing through the liquid crystal is absorbed by the surrounding dye molecules and a dark state will be formed. When the dye molecules are arranged in a direction parallel to the incident direction of the light (that is, the dye molecules basically stand along a direction perpendicular to the substrate surface), the light can pass through the dye molecules standing vertically, and a bright state is formed. The dye molecules are dichroic dye and can be dispersed in the liquid crystal, and the dye molecules rotate when the liquid crystal rotates. Based on the above reasons, the display device 10 of
Furthermore, since the quantum dots possess the function of depolarization, the color converting layer 400 doped with quantum dots must be disposed outside the polarizer, and thus the polarizer must be an in-cell polarizer of which the manufacturing process is relatively complicated. Therefore, the manufacturing process of the color converting layer 400 doped with quantum dots can be simplified when the manufacturing process of a polarizer is omitted.
Besides, blue phase liquid crystal, polymer dispersed liquid crystal and self-assembled liquid crystal all can be aligned without needing an alignment layer. Since the process temperature of the color converting layer 400 doped with quantum dots is about 120-130° C., and the alignment layer normally has a higher process temperature (such as 220-230° C.); when the manufacturing process of an alignment layer is omitted, the manufacturing process of the color converting layer 400 doped with quantum dots can be simplified, and the color converting layer 400 doped with quantum dots can be less affected by thermal processes.
As indicated in
In some embodiments as indicated in
In comparison to the display device 10 of previous embodiment, the display device 20 of the embodiment as indicated in
As disclosed above, the display device 20 of the present embodiment may not include a polarizer but still includes two alignment layers, and therefore has a wider range of selection in terms of liquid crystals. Basically, all dye doped liquid crystals may be used in the present embodiment.
As indicated in
In some embodiments as indicated in
In comparison to the display device 10 of previous embodiment, the display device 30 of the embodiment as indicated in
In an embodiment as indicated in
In an embodiment as indicated in
In an embodiment as indicated in
In an embodiment as indicated in
In an embodiment as indicated in
Conventionally, a polarizer is attached on the outer substrate of the panel after the manufacture of the liquid crystal display panel is completed. As disclosed above, the color converting layer 400 doped with quantum dots must be disposed outside the polarizer, and the polarizer must be an in-cell polarizer of which the manufacturing process is relatively complicated. For example, the in-cell polarizer may require a coating process, a rubbing alignment process, and etc. An example of a commonly seen in-cell polarizer is such as a wire grid polarizer.
In contrast, in the present embodiment, the second polarizer 900 manufactured by a conventional stretching process may firstly be attached on the third substrate 930, and then the second polarizer 900 together with the third substrate 930 are disposed in the display device 30-3. Thus, the manufacturing process of the polarizer may be separated from the manufacturing process of the color converting layer 400 doped with quantum dots and/or the manufacturing process of the alignment layer, hence avoiding the problem of negative influence caused by thermal processes as disclosed above.
As indicated in
In some embodiments, the display medium 300 may include dye doped liquid crystal; the first polarizer 800 may be a linear polarizer; and the first alignment layer 600 may be a horizontal alignment layer.
In an embodiment as indicated in
In some embodiments as indicated in
In the present embodiment, the first alignment layer 600 disposed on only one side can provide a basic alignment effect. In order to have better control of the liquid crystal, the first alignment layer 600 is preferably a horizontal alignment layer, and adopting polymer stabilized liquid crystal can further improve the alignment effect as well.
In the present embodiment, the first polarizer 800 disposed on only one side can polarize the incident light to increase the light absorption efficiency of the dye molecules. When the display medium 300 includes dye doped nematic liquid crystal or dye doped cholesteric liquid crystal, the light absorption effect of the dye molecules can further be increased.
In some embodiments, by adopting the structure as previously shown in such as
In some embodiments, by adopting the structures as previously shown in such as
In some embodiments, by adopting the structure as previously shown in such as
As indicated in
In some embodiments, the display medium 300 may include dye doped liquid crystal. In some embodiments, the display medium 300 may include cholesteric liquid crystal.
For example, the display medium 300 may be formed of polymer stabilized cholesteric liquid crystal, the first polarizer 800 may be a linear polarizer, and the first alignment layer 600 may be a horizontal alignment layer. In an embodiment, the first polarizer 800, which linearly polarizes the incident light, is disposed in conjunction with a quarter wavelength phase retardation film 940 to circularly polarize the incident light.
In the present embodiment, when the display medium 300 is formed of cholesteric liquid crystal doped with a chiral dopant, a cell gap/chiral pitch (d/p) design may be used, such that when no voltage is applied, the circular polarized light is blocked and a dark state is formed; when a voltage is applied to rearrange the liquid crystal, the circular polarized light can pass through the rearranged liquid crystal to form a bright state.
In some embodiments, the display devices 50 and 60 of
As indicated in
In an embodiment, the display medium 300 of
In an embodiment as indicated in
In an embodiment as indicated in
In the present embodiment, when the display device 60 includes a first electrode 910 disposed on only one side of the display medium 300, a horizontal electrical field is generated when a voltage is applied to the first electrode 910. When the liquid crystal material of the display medium 300 is operated in an in-plane switch (IPS) mode, the first electrode 910 is operated under two different voltages for generating a horizontal electrical field. When the liquid crystal material of the display medium 300 is operated in a fringe-field switch (FFS) mode, an added electrode (not illustrated in the diagram) is further disposed between the first electrode 910 and the first substrate 100, and the first electrode 910 and the added electrode are operated under different voltages for generating a fringe electrical field. For example, self-assembled liquid crystal may be used in conjunction with the fringe electrical field or the horizontal electrical field; thus, when the display medium 300 is formed of self-assembled liquid crystal, the design of the first electrode 910 generating a horizontal electrical field may be adopted. However, self-assembled liquid crystal is for exemplification purpose only, not for limiting. The absorption axis of the first polarizer 800 and the absorption axis of the second polarizer 900 are perpendicular to each other. When a voltage is applied, the arrangement direction of the liquid crystal will be fixed along the direction of the horizontal electrical field, and a bright state will be formed. When no voltage is applied and no electrical field is generated, the arrangement of the liquid crystal is random, and a dark state will be generated if the absorption axis of the first polarizer 800 and the absorption axis of the second polarizer 900 are perpendicular to each other.
While the disclosure has been described by way of example and in terms of the preferred embodiment (s), it is to be understood that the disclosure is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201611024645.4 | Nov 2016 | CN | national |
