Liquid crystal display panel and display device

The present disclosure relates to a liquid crystal display panel and a display device. The liquid crystal display panel includes a display area; and a non-display area surrounding the display area, wherein the display area includes a plurality of sub-areas, each of the plurality of sub-areas is provided with a plurality of pixel electrodes, all of the pixel electrodes in a sub-area have an identical brightness control parameter; and the brightness control parameter of the pixel electrodes in at least one sub-area is different from the brightness control parameter of the pixel electrodes in another sub-area. By setting different brightness control parameters based on different temperature rise in the sub-areas, the problem of poor Gamma uniformity of the display panel can be solved, and the possibility of occurrence of ghost can be reduced, thereby increasing display quality of the liquid crystal display panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to Chinese Patent Application No. 201710403709.X, filed on Jun. 1, 2017, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of display technologies and, in particular, to a liquid crystal display panel and a display device.

BACKGROUND

At present, there is increasing need on products with more pixels per inch (Pixels Per Inch, PPI) and products having integrated an array substrate with touch control function. However, power consumption of an integrated circuit (Integrated Circuit, IC) which supports the above two types of products is much higher than power consumption of an IC for a normal product. It is well known that, high power consumption leads to temperature rise of the IC.

In another aspect, since the product with more PPI has poor transmittance, backlight with high brightness is needed. A general solution is to increase current of a light-emitting diode (Light-Emitting Diode, LED) or increase the number of the LED. Of course, the above manner also leads to increase of power consumption of the LED, causing excessively high temperature of the LED.

Since the temperature of both the IC and the LED is excessively high, temperature of the display area close to an IC end will rise, and the temperature difference in a panel will increase due to poor heat dissipation effect of the panel.

Since temperature influences parameters such as viscosity, elastic coefficient and dielectric constant of the liquid crystal, excessive temperature difference in the panel will lead to Gamma uniformity at different positions.

SUMMARY

The present disclosure provides a liquid crystal display panel and a display device, which can reduce the phenomenon of Gamma uniformity of the liquid crystal display panel, and improve display quality of the liquid crystal display panel.

A first aspect of the present disclosure provides a liquid crystal display panel. The liquid crystal display panel includes a display area and a non-display area surrounding the display area. The display area includes a plurality of sub-areas, each of the plurality of sub-areas is provided with a plurality of pixel electrodes, and all of the pixel electrodes in a sub-area have an identical brightness control parameter. The brightness control parameter of the pixel electrodes in at least one sub-area is different from the brightness control parameter of the pixel electrodes in another sub-area.

A second aspect of the present disclosure further provides a display device, the display device includes a liquid crystal display panel. The liquid crystal display panel includes: a display area and a non-display area surrounding the display area. The display area includes a plurality of sub-areas, each of the plurality of sub-areas is provided with a plurality of pixel electrodes, and all of the pixel electrodes in a sub-area have an identical brightness control parameter. The brightness control parameter of the pixel electrodes in at least one sub-area is different from the brightness control parameter of the pixel electrodes in another sub-area.

The technical solutions provided by the present disclosure can achieve the following beneficial effects:

In the present disclosure, the brightness control parameters can influence an electric field direction or magnitude of an electric field force, and the electric field direction or the magnitude of the electric field force will influence a deflection angle of the liquid crystal. In a certain range, the larger the deflection angle of the liquid crystal, the larger the brightness after light penetrating through the liquid crystal and emitting out of the liquid crystal display panel. Thus, it is known that, the Gamma uniformity of the liquid crystal display panel can be improved by setting different brightness control parameters based on different temperature rise in the sub-areas, so as to reduce the possibility of occurrence of ghost, thereby increasing display quality of the liquid crystal display panel.

It should be understood that, the above general description and the detailed description as follows are merely exemplary, which cannot limit the present disclosure.

REFERENCE SIGNS

The drawings herein are incorporated into the present description and form a part thereof, which show embodiments of the present disclosure, and are used to explain the principle of the present disclosure together with the description.

DESCRIPTION OF EMBODIMENTS

The present disclosure will be described in further detail with reference to the following embodiments and the accompanying drawings.

It should be noted that, the directional expressions such as “up”, “down”, “left” and “right” used in the present disclosure are intended to describe from the view shown in the figures, which shall not be interpreted as limiting the embodiments of the present disclosure. In addition, in the context, it should be understood that, when an element is formed “above” or “below” another element, the element may be formed directly above or below the another element, or may be formed indirectly above or below the other element by means of an intermediate element.

FIG. 1illustrates a schematic view showing temperature rise at different test points of a display panel according to the prior art. As shown inFIG. 1, taking a 5.5 FHD touch embed display (Touch Embed Display, TED) product as an example, a maximum temperature difference among 9 test points is greater than 2.5° C.

FIG. 2illustrates a schematic view I of pixel electrodes in sub-areas according to an embodiment of the present disclosure. As shown inFIGS. 2-3, there exist a maximum difference between a gamma value of 127 gray scale close to the IC end (the 6thpoint) and a gamma value away from the IC end (1st point and 7th point). At this time, a concentration of foreign ion in a liquid crystal box will increase as the temperature of the panel increases, accordingly, the closer to the IC end, the greater the possibility of occurrence of ghost on the panel. As shown inFIG. 3, an embodiment of the present disclosure provides a liquid crystal display panel1, and the liquid crystal display panel1includes a display area11and a non-display area12. Generally, the non-display area12surrounds the display area11. The display area11is located at a central area of the display panel1. The display area11is also called as the pixel area, the pixel area includes a plurality of pixel units arranged in a matrix.

The display area11includes a plurality of sub-areas111, the number of the sub-areas111is n, and n is greater than or equal to 2, and each sub-area111includes a plurality of pixel electrodes1111. In order to improve Gamma uniformity in the liquid crystal display panel, it is proposed in the present disclosure that, in a same sub-area111, brightness control parameters of the pixel electrodes1111are the same; in different sub-areas111, brightness control parameters of the pixel electrodes1111in at least one sub-area111are different from brightness control parameters of the pixel electrodes1111in another sub-area111.

In the embodiment shown inFIGS. 2-3, brightness control parameters of the pixel electrodes1111in the right-bottom sub-area111is different from brightness control parameters of the pixel electrodes1111in the other three sub-areas111.

The brightness control parameters can influence an electric field direction or magnitude of an electric field force, and the electric field direction or the magnitude of the electric field force will influence a deflection angle of the liquid crystal. In a certain range, the larger the deflection angle of the liquid crystal, the larger the brightness of the light after transmitting through the liquid crystal and then emitting out of the liquid crystal display panel1. Thus, it is known that, the Gamma uniformity of the liquid crystal display panel1can be improved by setting different brightness control parameters based on different temperature rise in the sub-areas111, so as to reduce the possibility of occurrence of ghost, thereby increasing display quality of the liquid crystal display panel1.

The brightness control parameters include an angle θ of the pixel electrode1111, as shown inFIG. 4, the angle θ refers to an included angle between an extending direction of a body portion of the pixel electrode1111and a first direction. The first direction is a direction perpendicular to an extending direction of a gate line. If the liquid crystal is a positive liquid crystal, an original alignment direction (F direction inFIG. 4) is substantially perpendicular to the gate line. The pixel electrode1111includes a body portion1111aextending along a straight line direction and an additional portion1111bconnected with the body portion1111a. The angle θ is an included angle between the extending direction of the body portion1111aand the first direction, and the first direction is a direction perpendicular to the extending direction of the gate line.

It should be noted that, the liquid crystal3has two types: positive liquid crystal and negative liquid crystal. An original alignment direction of the positive liquid crystal is a column direction of arrangement of the pixel units, an original alignment direction of the negative liquid crystal is perpendicular to the column direction. Preferably, an extending direction of a data line electrically connected with the pixel electrode1111is not parallel to the column direction. The embodiments of the present disclosure mainly take the positive liquid crystal as an example for illustration.

The brightness control parameters further include the number of the slits1111c, as shown inFIG. 4, the slit1111cis a slit provided in the pixel electrode1111, the slit1111cprovide space for the electric field lines to pass through. It should be understood that, the more the slits1111c, the more the electric field lines passing through the slits1111c, and the greater the electric field force.

Based on the above description, the brightness control parameters include the angle θ of the pixel electrode1111and the number of the slits1111cof the pixel electrode1111. In an aspect, the angle θ of the pixel electrode1111determines an electric field direction of the display panel1(the electric field direction is always perpendicular to the body portion1111a) after being powered on, and the electric field direction directly influences the angle θ of the liquid crystal3. In a certain range, the larger the deflection angle of the liquid crystal3, the greater the brightness of the light after passing through the liquid crystal and emitting out of the liquid crystal display panel1. In another aspect, the number of the slits1111cof the pixel electrode1111directly influences the number of the electric field lines passing through the slit1111cafter the liquid crystal display panel1is powered on, thus influences the magnitude of the electric field force, and the magnitude of the electric field force will also influence the angle θ of the liquid crystal3. Therefore, by setting different angles θ of the pixel electrodes1111in different sub-areas111, or by setting different numbers of slits1111of the pixel electrode1111in different sub-areas111, the problem of poor Gamma uniformity of the liquid crystal display panel can be improved.

In an embodiment, angles θ of the pixel electrodes1111in the same sub-area111are the same, while in different sub-areas111, an angle θ of the pixel electrodes1111in at least one sub-area111is set to be different from an angle θ of the pixel electrodes1111in another sub-area111. In any two sub-areas1111, an angle θ of the pixel electrodes1111in a sub-area with a relative high average temperature is greater than an angle θ of the pixel electrodes1111in a sub-area with a relative low average temperature. The average temperature can be obtained by detecting temperature at a plurality of detecting points in the sub-area111, the more the selected detecting points, the more accurate the detected average temperature. Moreover, a reasonable selection of the positions of detecting points will also influence the result of the average temperature, those skilled in the art would be able to perform an accurate detection of the average temperature of the sub-areas111according to the above principles.

As shown inFIG. 5, the display area11includes two sub-areas111, respectively a first sub-area A1and a second sub-area A2. The detecting points in the first sub-area A1are respectively point3, point6and point9, and the detecting points in the second sub-area A2are respectively point1, point4, point7, point2, point5and point8.

In an embodiment, the angle θ of the pixel electrodes1111in the first sub-area A1is set as 10°, and the angle θ of the pixel electrodes1111in the second sub-area A2is set as 9.33°. Combining the above principle and based on the actual detected result, it can be known that, each increase of 0.67° of the angle θ of the pixel electrode1111in the second sub-area A2corresponds to an increase of 0.03° of the brightness ratio G127/G255 (a ratio of gray scale 127 to gray scale 255) of the first sub-area A1and the second sub-area A2. Thus, the Gamma uniformity in the two sub-areas is improved.

Of course, the number of the sub-areas111is not limited to 2 as shown inFIG. 5, and in other embodiments, the number of the sub-areas111can be three or more. It should be understood that, when the liquid crystal display panel1is divided into more sub-areas111, the angle θ of the pixel electrodes111in each sub-area111can be set correspondingly, so as to better improve the Gamma uniformity of the liquid crystal display panel1.

As shown inFIG. 6, optionally, the display area11includes nine sub-areas111, which are a first sub-area A1, a second sub-area A2, a third sub-area A3, a fourth sub-area A4, a fifth sub-area A5, a sixth sub-area A6, a seventh sub-area A7, an eighth sub-area A8and a ninth sub-area A9, respectively. The first sub-area A1, the second sub-area A2, the third sub-area A3, the fourth sub-area A4, the sixth sub-area A6, the seventh sub-area A7, the eighth sub-area A8and the ninth sub-area A9surround the fifth sub-area A5. At this time, the average temperature value of the fifth sub-area A5can be used as a reference temperature value, and the Gamma uniformity of the liquid crystal display panel is improved by adjusting the angle θ of the pixel electrodes1111in the other eight sub-areas rather than the fifth sub-area A5.

Generally, the closer to the heat source2a sub-area of the liquid crystal display panel, the higher the average temperature of the sub-area, which means, the average temperature of a sub-area111is in direct proportion to the distance between the sub-area111and the heat source2. For example, as shown inFIG. 5andFIG. 6, the average temperature of each of the third sub-area A3, the sixth sub-area A6and the ninth sub-area A9is higher than the average temperature of any other sub-area. The heat source2can be any electric device that emits heat, and in the embodiment shown inFIGS. 5-6, the heat source2is an IC. Please refer toFIG. 7, the heat source2can also be a backlight source, such as an LED light.

In the liquid crystal display technique, it is known that, the extending direction of the body portion1111aof the pixel electrode1111is perpendicular to the direction of the electric field formed between the power-on common electrode and pixel electrode1111. Therefore, the extending direction of the body portion1111aof the pixel electrode1111is related to the rotating direction of the liquid crystal in the electric field. For a positive liquid crystal, the liquid crystal molecule tends to rotate to make its long axis parallel to the electric field direction; for a negative liquid crystal, the liquid crystal molecule tends to rotates to make its short axis parallel to the electric field direction.

In the present disclosure, for any two sub-areas111, the range of the angle θ of the pixel electrodes1111in the sub-area with lower average temperature can be set as 1°-20°.

Moreover, according to actual detected result, for any two sub-areas1111, the difference between the angle θ of the pixel electrodes1111in one sub-area with a higher average temperature and the angle θ of the pixel electrodes1111in the other sub-area with a lower average temperature can be set in a range of 3°-5°. In this range, it is verified through experiments that the gamma uniformity of the liquid crystal display panel can be improved.

In the present disclosure, the module transmission rate of the liquid crystal display panel1is tested, and the test results are shown in Table 1. Table 1 shows the module transmission rate of the liquid crystal display panel1when the angle θ of the pixel electrodes1111in a same sub-area is set as 6°, 10° and 14°, respectively.

From Table 1, it is known that when the angle θ of the pixel electrodes1111in one sub-area111is respectively 6°, 10° and 14°, the module transmission rate is respectively 3.99%, 4.04%, 4.08%, when the angle θ of the pixel electrodes1111in one sub-area111increases from 6° to 10°, the white state G255 transmission rate increases for 1.25%, and when the angle θ of the pixel electrodes1111in one sub-area111increases from 6° to 14°, the white state G255 transmission rate increases for 2.26%. According to experience values, the white state brightness is generally 450 nits, when the difference of the angle θ of the pixel electrodes1111in different sub-areas111is 1°, the brightness difference is only 1.4 nits. The reason lies in that, the angle θ of the pixel electrode1111determines an electric field direction of the liquid crystal display panel1(the electric field direction is always perpendicular to the body portion1111a) after being powered on, and the electric field direction directly influences the deflection angle of the liquid crystal. In a certain range, the larger the deflection angle of the liquid crystal, the greater the brightness of the light after passing through the liquid crystal and emitting out of the liquid crystal display panel1. Therefore, the brightness difference of the liquid crystal display panel1can be significantly reduced by appropriately reducing the difference of the angle θ. Moreover, if the white state brightness difference of the sub-areas is excessively great, it can be corrected by adjusting a corner angle α of the pixel electrode1111.

The corner angle of the pixel electrode1111is an included angle between the additional portion1111band the body portion1111a. Please refer toFIG. 4, in the shape formed by orthogonal projections of the additional portion1111band the body portion1111aon the array substrate, the included angle at a joint position of the additional portion1111band the body portion1111ais the corner angle α. In order to distinguish from the angle θ of the pixel electrodes1111, the corner angle α can be recorded as a first included angle, and the white state brightness difference can be corrected by setting the first included angle as a non-zero included angle.

Further, in a same sub-area, the joint position of the additional portion1111band the body portion1111acan be provided with a plurality of angles α. That is, for example, in the embodiment shown inFIG. 4, the number of the corner angle α can be two, i.e., a first included angle α and a first included angle β, and α is not identical to β.

Moreover, for different sub-areas, it can be set that at least one corner angle α in at least one sub-area is not identical to a corner angle α in another sub-area, so as to more accurately correct the white state brightness difference in different sub-areas.

It should be noted that, the manner of correcting white state brightness difference is not limited to the above described manner, and in other embodiments, the white state brightness difference can also be corrected by adjusting the brightness distribution of the backlight source.

As described above, the brightness control parameters further include the number of the slits1111cof the pixel electrode1111, that is, the gamma uniformity of the liquid crystal display panel can also be improved by setting the number of the slits1111cof the pixel electrodes1111in different sub-areas111to be different.

Similarly, the display area11can be divided into a plurality of sub-areas111, the number of the sub-area is n, and n is greater than or equal to 2, and each sub-area111is provided with a plurality of pixel electrodes1111. In order to improve gamma uniformity of the liquid crystal display panel, the following arrangement can be adopted, that is, in any two sub-areas111, the number of the slit1111cof the pixel electrode1111in one sub-area with a higher average temperature is less than the number of the slit1111cof the pixel electrode1111in the other sub-area with a lower average temperature.

According to an embodiment, as shown inFIG. 8, the display area11includes two sub-areas111, respectively a first sub-area A1and a second sub-area A2. Through sampling detecting points, the average temperature of the first sub-area A1is greater than the average temperature of the second sub-area A2. At this time, it can be set that the number of the slits1111cof the pixel electrode1111in the first sub-area A1as two, and the number of the slits1111cof the pixel electrode1111in the second sub-area A2as three. It is verified by experiments that, when other conditions are kept unchanged, the brightness ratio G127/G255 increases, and the increased value is 0.035.

Based on the above embodiments, the module transmission rate of the liquid crystal display panel is further tested, and the test results are shown in Table 2. The mark accuracy (MA) of Table 2 is respectively 0.5 μm, 1 μm, 1.5 μm, 2 μm. The module transmission rate is presented when the numbers of slits1111cof the pixel electrode1111in the two sub-areas are respectively two and three.

From Table 2, it is known that, under different contra-position accuracies, when the number of the slits1111cof the pixel electrode1111in the first sub-area A1is two, the module transmission rate is respectively 4.93%, 4.82%, 4.57%, 4.36%; when the number of the slits1111cof the pixel electrode1111in the second sub-area A2is three, the module transmission rate is respectively 5.02%, 4.93%, 4.67%, 4.44%. Under different contra-position accuracies, comparing the module transmission rate of the first sub-area A1having two slits1111cwith the module transmission rate of the second sub-area A2having three slits1111c, the decrease proportion of the module transmission rate of the first sub-area A1with respect to the second sub area A2is respectively 1.8%, 2.2%, 2.3%, 1.8%, the module transmission rate difference between the two sub-areas is approximately 2%, so that the gamma uniformity of the liquid crystal display panel is improved.

In order to form an electric field between the common electrode and the pixel electrode1111, the number of the slit1111cof the pixel electrode1111is at least one, and in the present embodiment, it can be set that, in any two sub-areas111, the number of the slit1111cof the pixel electrode1111in a sub-area with lower average temperature is 1-15.

Moreover, in any two sub-areas111, a difference between the number of slit1111cof the pixel electrode1111in one sub-area with a higher average temperature and the number of slit1111cof the pixel electrode1111in a sub-area with a lower average temperature is in the other range of 1-5.

Of course, in other embodiments, the arrangement may be different from above, those of ordinary skill in the art can make reasonable selection according to the specific application scenario of the liquid crystal display panel.

In the embodiments shown inFIG. 5andFIG. 8, the plurality of sub-areas111is strip-like areas and is arranged in parallel. The heat source2is arranged at a side of the first sub-area A1, and the side is in a width direction of the first sub-area A1and away from the second sub-area A2. Such a division of the sub-areas is relatively simple and reasonable, which facilitates to improve the display quality of the liquid crystal display panel.

The present disclosure does not limit the specific structure of the pixel electrode1111, for example, the pixel electrode1111in each sub-area111can be a pixel electrode1111with a single domain structure or a pixel electrode1111with a dual-domain structure, or can also be a pixel electrode1111with a pseudo dual-domain structure.

Please refer toFIG. 9, when the pixel electrode1111in each sub-area111is a pixel electrode1111with a dual-domain structure, the dual-domain structure is divided into an upper domain and a lower domain. The angle θ of the pixel electrode1111in the upper domain of the sub-area111and the angle θ of the pixel electrode1111in the lower domain of the sub-area111have the same value but opposite directions.

In the liquid crystal display panel provided by the present disclosure, the liquid crystal molecule can be a positive liquid crystal or a negative liquid crystal.

Please refer toFIG. 10, based on the above liquid crystal display panel1, a second aspect of the present disclosure further provides a display device100, and the display device includes a liquid crystal display panel1according to any one of the above embodiments.

The above are merely preferred embodiments of the present disclosure, which will not limit the present disclosure. For those of ordinary skill in the art, the present disclosure can have various modifications and variations. Any modification, equivalent replacement and improvement made based on the present disclosure shall fall into the protection scope of the present disclosure.