1. Field of Invention
The invention relates to a display panel and a display device and, in particular, to a display panel and a display device having a higher transmittance.
2. Related Art
With the progress of technologies, display devices have been widely applied to various kinds of fields. Especially, liquid crystal display (LCD) devices, having advantages such as compact structure, low power consumption, less weight and less radiation, gradually take the place of cathode ray tube (CRT) display devices, and are widely applied to various electronic products, such as mobile phones, portable multimedia devices, notebooks, LCD TVs and LCD screens.
A conventional liquid crystal display (LCD) apparatus mainly includes an LCD panel and a backlight module disposed opposite to the LCD panel. The LCD panel mainly includes a thin film transistor (TFT) substrate, a color filter (CF) substrate and a liquid crystal layer disposed between the two substrates. The CF substrate, the TFT substrate and the LC layer can form a plurality of pixel units disposed in an array. The backlight module emits the light passing through the LCD panel, and the pixel units of the LCD panel can display images accordingly.
For the same luminance, a display panel with a higher transmittance can save more energy for the display device. Therefore, the industry strives to increase the transmittance of the display panel to save more energy and enhance the product competitiveness.
An objective of the invention is to provide a display panel and a display device having a higher transmittance so as to enhance the product competitiveness.
To achieve the above objective, a display panel according to the invention comprises a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer disposed between the first and second substrates, and a pixel array disposed on the first substrate and including at least one pixel, which includes a first electrode layer, a second electrode layer and an insulation layer disposed between the first and second electrode layers. The second electrode layer has n electrode portions, the electrode portions are spaced from each other and disposed in parallel along a first direction, an electrode width of one of the electrode portions along the first direction is denoted by W (μm), the maximum width of a light-emitting area of the pixel along the first direction is denoted by Ax (μm), and the equation is satisfied as below:
wherein, n is a positive integer, and the unit of W and Ax is μm.
To achieve the above objective, a display device according to the invention comprises a display panel. The display panel includes a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer disposed between the first and second substrates, and a pixel array disposed on the first substrate and including at least one pixel, which includes a first electrode layer, a second electrode layer and an insulation layer disposed between the first and second electrode layers. The second electrode layer has n electrode portions, the electrode portions are spaced from each other and disposed in parallel along a first direction, an electrode width of one of the electrode portions along the first direction is denoted by W (μm), the maximum width of a light-emitting area of the pixel along the first direction is denoted by Ax (μm), and the equation is satisfied as below:
wherein, n is a positive integer, and the unit of W and Ax is μm.
In one embodiment, when a light passes through the pixel, the pixel has a brightness distribution along the first direction, and the maximum width of the light-emitting area of the pixel along the first direction is the full width at half maximum (FWHM) of the brightness distribution.
In one embodiment, the pixel further includes a scan line, and the first direction is substantially parallel to the direction of the scan line.
In one embodiment, the second electrode layer further includes a first connecting portion, which surrounds the electrode portions and is connected to the electrode portions.
In one embodiment, the second electrode layer further includes a second connecting portion, which is disposed on the opposite sides of the electrode portions and connected to the electrode portions.
As mentioned above, in the display panel and display device of the invention, the pixel array includes at least a pixel, and the insulation layer of the pixel is disposed between the first electrode layer and the second electrode layer. The second electrode layer has n electrode portions. The electrode portions are spaced from each other and disposed in parallel along the first direction, and the electrode width of one of the electrode portions along the first direction is denoted by W. The maximum width of the light-emitting area of the pixel along the first direction is denoted by Ax. The equation is satisfied as below:
wherein, n is a positive integer.
Accordingly, when the number (n) of the electrode portions of the second electrode layer, the electrode width (W) and the maximum width (Ax) of the light-emitting area of the pixel along the first direction comply with the above equation, the ratio of the dark area of the pixel can be minimized so as to obtain the maximum transmittance of the pixel. Therefore, the display panel and the display device of the invention can have a higher transmittance and the product competitiveness can be enhanced.
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.
As shown in
The display panel 1 further includes a pixel array, which is disposed on the first substrate 11 and has at least a pixel P. In this embodiment, the pixel array includes a plurality of pixels, which are disposed between the first and second substrates 11 and 12 and in an array along the first and second directions X and Y. Besides, the display panel 1 can further include a plurality of scan lines S and a plurality of data lines D, and the scan lines S and the data lines D cross each other to define the area of the pixel array.
As shown in
The insulation layer 142 covers the first electrode layer 141 and the data line D, and the second electrode layer 143 is disposed on the insulation layer 142. Herein, the insulation layer 142 is disposed between the first electrode layer 141 (with the data line D) and the second electrode layer 143 to separate the first electrode layer 141, the data line D and the second electrode layer 143 for avoiding a short circuit. The material of the insulation layer 142 may include SiOx, SiNx or the like, but the invention is not limited thereto. Each of the first and second electrode layers 141 and 143 is a transparent conductive layer, and the material thereof may include indium tin oxide (ITO) for example. In this embodiment, the first electrode layer is a pixel electrode and electrically connected to the data line D, and the second elector delayer 143 is a common electrode. In other embodiments, however, the first electrode layer 141 can be a common electrode while the second electrode layer 143 is a pixel electrode.
The second electrode layer 143 includes n electrode portions 1431 (n is a positive integer), and further includes a first connecting portion 1432 that surrounds the electrode portions 1431 and is connected to the electrode portions 1431. Herein as shown in
As shown in
The filter layer (not shown) is disposed on the side of the second substrate 12 and the black matrix BM facing the first substrate 11 or disposed on the first substrate 11. Since the black matrix BM is opaque, a corresponding opaque area can be formed on the second substrate 12 so as to define a transparent area. Therefore, when the light passes through the pixel P, the pixel P will have a light-emitting area (the area permeable to light). The black matrix BM includes a plurality of light-blocking segments, and at least one light-blocking segment is disposed between two adjacent filter portions of the filter layer. In this embodiment, the black matrix BM and the filter layer are both disposed on the second substrate 12. In other embodiments, however, the black matrix BM or the filter layer can be disposed on the first substrate 11 for making a BOA (BM on array) substrate or a COA (color filter on array) substrate. To be noted, the above-mentioned structure of the substrate is just for example but not for limiting the scope of the invention. Moreover, the display panel 1 can further include a protection layer (e.g. over-coating, not shown), which can cover the black matrix BM and the filter layer. The protection layer can include photoresist material, resin material or inorganic material (e.g. SiOx/SiOx), protecting the black matrix BM and the filter layer from being damaged during the subsequent processes.
When the scan lines S of the display panel 1 receive a scan signal sequentially, the TFT (not shown) corresponding to each of the scan lines S can be enabled. Then, the data signals can be transmitted to the corresponding pixel electrodes through the data lines D and the display panel 1 can display images accordingly. In this embodiment, the gray-level voltage can be transmitted to the first electrode layer 141 (pixel electrode) of each of the pixels P through each of the data lines D, and an electric filed can be thus formed between the first electrode layer 141 and the second electrode layer 143 (common electrode) to drive the LC molecules of the LC layer 13 to rotate on the plane that is in the first and second directions X and Y. Therefore, the light can be modulated and the display panel 1 can display images accordingly.
However, when the electric field is formed between the first electrode layer 141 and the second electrode layer 143 (common electrode) to drive the LC molecules to rotate, the horizontal rotation of the LC molecules in the central area of each of the electrode portions 1431 and in the area between the adjacent electrode portions 1431 is limited because of the electric field distribution (denoted by the dotted lines in FIG. 1B) in the said areas. Hence, when the light passes through the pixel P, the dark regions will be generated in the central area of each of the electrode portions 1431 and in the area between the adjacent electrode portions 1431, reducing the transmittance of the display panel 1. So, decreasing the said area of the dark regions indicates the increment of the transmittance of the display panel 1, and the increment of the transmittance indicates the energy can be saved and the product competitiveness can be enhanced.
Accordingly, how to minimize the area of the dark regions to increase the transmittance of the display panel 1 will be illustrated as below by referring to
As shown in
As shown in
Hence, the transparent area T of the pixel P can be obtained by subtracting the area of the dark regions (including the triangular dark regions D2 and the straight dark regions D1) from the area of the light-emitting area, as the following equation:
To obtain the maximum, the differential is derived from the equation as below:
Then, the equation can be obtained as below:
T′=(2n+1)−2×Ax2×2−W×R×Ay×2
When T=0, the maximum exists, so the equation becomes:
By substituting Ay≈3Ax into the above equation, the equation becomes:
Again, by substituting R≈0.1 into the above equation, the equation becomes:
Accordingly, the optimized n (positive integer) in this embodiment will comply with the following equation:
In this condition, the ratio of the area of the dark regions to the area of the light-emitting area of the pixel P can be minimized so as to obtain the maximum transmittance of the pixel P, and therefore the display panel 1 is configured with a higher transmittance and the product competitiveness can be increased.
As shown in
As shown in
As shown in
The other technical features of the display panels 1a, 1b, 1c can be comprehended by referring to the same elements of the display panel 1, and therefore they are not described here for conciseness.
As shown in
Summarily, in the display panel and display device of the invention, the pixel array includes at least a pixel, and the insulation layer of the pixel is disposed between the first electrode layer and the second electrode layer. The second electrode layer has n electrode portions. The electrode portions are spaced from each other and disposed in parallel along the first direction, and the electrode width of one of the electrode portions along the first direction is denoted by W. The maximum width of the light-emitting area of the pixel along the first direction is denoted by Ax. The equation is satisfied as below:
wherein, n is
a positive integer.
Accordingly, when the number (n) of the electrode portions of the second electrode layer, the electrode width (W) and the maximum width (Ax) of the light-emitting area of the pixel along the first direction comply with the above equation, the ratio of the area of the dark regions to the area of the light-emitting area of the pixel can be minimized so as to obtain the maximum transmittance of the pixel. Therefore, the display panel and the display device of the invention can have a higher transmittance and the product competitiveness can be enhanced.
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 | Name | Date | Kind |
---|---|---|---|
5831707 | Ota et al. | Nov 1998 | A |
6317188 | Shibahara | Nov 2001 | B1 |
6469765 | Matsuyama et al. | Oct 2002 | B1 |
8692961 | Yonemura | Apr 2014 | B2 |
8730560 | Sonoda | May 2014 | B2 |
9053666 | Minami | Jun 2015 | B2 |
20060050081 | Kobayashi | Mar 2006 | A1 |
20070236424 | Kimura | Oct 2007 | A1 |
20080018563 | Shinohe | Jan 2008 | A1 |
20080143649 | Asaki | Jun 2008 | A1 |
20090315821 | Kwak | Dec 2009 | A1 |
20100007282 | Yamamoto | Jan 2010 | A1 |
20100309419 | Oka et al. | Dec 2010 | A1 |
20110096065 | Handa | Apr 2011 | A1 |
20110169719 | Onishi | Jul 2011 | A1 |
20120013647 | Fang | Jan 2012 | A1 |
20120013649 | Higashi | Jan 2012 | A1 |
20120105503 | Tada | May 2012 | A1 |
20120274617 | Fukuda | Nov 2012 | A1 |
20130027441 | Kabe | Jan 2013 | A1 |
Number | Date | Country |
---|---|---|
2008-76978 | Apr 2008 | JP |
2010-271442 | Dec 2010 | JP |
Entry |
---|
Report of Utility Model Technical Opinion issued by the Japan Patent Office for corresponding Japanese Utility Model Application No. 2014-003311 on Mar. 22, 2016. |
Number | Date | Country | |
---|---|---|---|
20150356939 A1 | Dec 2015 | US |