Liquid crystal display panel used in normally black mode and display apparatus using the same

The present invention provides a liquid crystal display (LCD) panel and a display apparatus using the same. The LCD panel comprises a first substrate, a second substrate and a liquid crystal layer. The second substrate comprises pixels, wherein, when images are displayed by the pixels, a voltage difference between a first voltage of the first sub-pixels and a second voltage of the second sub-pixels is inversely proportional to a grayscale of the images displayed by the pixels, and the first voltage is higher than the second voltage. The present invention can mitigate the viewing angle problem of the pixels.

FIELD OF THE INVENTION

The present invention relates to a field of a liquid crystal display technology, and more particularly to a liquid crystal display (LCD) panel and a display apparatus using the same.

BACKGROUND OF THE INVENTION

Liquid crystal displays (LCDs) have been widely applied in electrical products. Currently, most of LCDs are backlight type LCDs which comprise a liquid crystal panel and a backlight module. The liquid crystal panel is composed of two transparent substrates and a liquid crystal sealed there-between, and the liquid crystal panel has pixels for displaying images.

At present, a vertical alignment (VA) technology has been developed for LCD panels, and has some advantages, such as wide viewing angle, high aperture ratio, high contrast and simple process.

However, when the images of the VA type LCD is viewed from the front or obliquely, the displayed image effects will be different at different viewing angles, and especially in a normally black mode, the viewing angle problem is more prominent, thereby greatly deteriorating a display quality of the LCD.

As a result, it is necessary to provide an LCD panel and a display apparatus using the same to solve the problems existing in the conventional technologies, as described above.

SUMMARY OF THE INVENTION

The present invention provides an LCD panel and a display apparatus using the same to solve the viewing angle problem existing in the conventional LCD.

A primary object of the present invention is to provide a liquid crystal display panel, and the liquid crystal display panel comprises: a first substrate; a second substrate comprising a plurality of pixels, wherein each of the pixels includes a first sub-pixel and a second sub-pixel, and the first sub-pixel includes a plurality of first branch portions, and there is a first space between the first branch portions, and the second sub-pixel includes a plurality of second branch portions, and there is a second space between the second branch portions, and the first space is less than the second space; and a liquid crystal layer thrilled between the first substrate and the second substrate; wherein, when images are displayed by the pixels, a first voltage is applied to the first sub-pixels, and a second voltage is applied to the second sub-pixels, and a voltage difference between the first voltage and the second voltage is inversely proportional to a grayscale of the images displayed by the pixels, and the first voltage is higher than the second voltage.

Another object of the present invention is to provide a display apparatus comprising a backlight module and the above-mentioned LCD panel.

In one embodiment of the present invention, a difference between the first space and the second space is larger than 1 μm.

In one embodiment of the present invention, the difference between the first space and the second space is in a range of 1 μm to 3 μm.

In one embodiment of the present invention, when the brightness of the images displayed by the pixels is lower than the predetermined brightness, a voltage difference between the first voltage and the second voltage is higher than 1 V.

In one embodiment of the present invention when the brightness of the images displayed by the pixels is lower than the predetermined brightness, the voltage difference between the first voltage and the second voltage is in a range of 1 V to 3V.

In one embodiment of the present invention, an area of the second sub-pixel is equal to or larger than an area of the first sub-pixel.

In the LCD panel and the display apparatus using the same of the present invention, with the use of the different branch spaces and the different driving voltages of the different sub-pixels in the pixels, the brightness difference between the different sub-pixels can be enlarged, so as to mitigate the viewing angle problem of the pixels.

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following embodiments are referring to the accompanying drawings for exemplifying specific implementable embodiments of the present invention. Furthermore, directional terms described by the present invention, such as upper, lower, front, back, left, right, inner, outer, side and etc., are only directions by referring to the accompanying drawings, and thus the used directional terms are used to describe and understand the present invention, but the present invention is not limited thereto.

The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for understanding and ease of description, but the present invention is not limited thereto.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, for understanding and ease of description, the thicknesses of some layers and areas are exaggerated. It will be understood that, when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present.

In addition, in the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. Furthermore, in the specification, “on” implies being positioned above or below a target element and does not imply being necessarily positioned on the top on the basis of a gravity direction.

Referring toFIG. 1, a partially cross-sectional view showing a liquid crystal display (LCD) panel according to one embodiment of the present invention is illustrated. The display apparatus of the present embodiment can comprises the liquid crystal display panel100and a backlight module (not shown). The liquid crystal display panel100is disposed opposite to the backlight module, and the backlight module may be realized as a side lighting backlight module or a bottom lighting backlight module to provide the liquid crystal display panel100with the back-light.

Referring toFIG. 1again, the liquid crystal display panel100may comprise a first substrate110, a second substrate120, a liquid crystal layer130, a first polarizer140and a second polarizer150. The liquid crystal layer130is formed between the first substrate110and the second substrate120. That is, the liquid crystal layer130is positioned at inner sides of the first substrate110and the second substrate120. The first polarizer140is disposed at an outer side of the first substrate110, and the second polarizer150is disposed at an outer side of the second substrate120.

Referring toFIG. 1, the first substrate110and the second substrate120may be realized as glass substrates or flexible plastic substrates. The first substrate110may be a glass substrate or other material substrate with color filters (CF), and the second substrate120may be a glass substrate or other material substrate with a thin film transistor (TFT) array. It notes that the CF and the TFT array may also be disposed on the same substrate in other embodiments.

Referring toFIG. 1again, the first substrate110can comprise a first electrode layer111, and the second substrate120can comprise a second electrode layer121. The first electrode layer111and the second electrode layer121are preferably made of a transparent and electrically conductive material, such as ITO, IZO, AZO, GZO, TCO or ZnO. A voltage can be applied to the liquid crystal molecules of the liquid crystal layer130by the first electrode layer111and the second electrode layer121. In this embodiment, the first electrode layer111may be a common electrode, and the second electrode layer121may be a pixel electrode.

Referring toFIG. 2, a layout view of pixels of the liquid crystal display panel according to one embodiment of the present invention is illustrated. The second substrate120further comprises a plurality of signal lines122, a plurality of active elements123and a plurality of pixels124. The signal lines122may be gate lines and data lines which are crisscrossed, thereby forming the pixels124arranged in an array. The active elements123may be thin film transistors (TFTs) disposed in the pixels124and electrically connected to the signal lines122and pixel electrodes of the pixels124, respectively. Each of the pixels124can corresponds to a color filter, such as a red, green or blue filter.

Referring toFIG. 2andFIG. 3,FIG. 3is a schematic diagram showing one pixel of the LCD panel according to one embodiment of the present invention. Each of the pixels124includes a first sub-pixel101and a second sub-pixel102, wherein an area of the second sub-pixel102may be equal to or larger than an area of the first sub-pixel101. A pixel electrode structure in each of the pixels124includes a first trunk portion103and a plurality of first branch portions104. A pixel electrode structure in each of the second sub-pixels102includes a second trunk portion105and a plurality of second branch portions106. The first trunk portion103and the second trunk portion105may be crisscross patterns. The branch portions104and106obliquely extend from the trunk portions103,105, and are arranged parallel to each other. In this case, the first branch portions104in each of the pixels124have an identical first line width L1and an identical first space S1there-between, and the second branch portions106in each of the second sub-pixels102have a second line width L2and a second space S2there-between, and the first space S1in the first sub-pixels101is less than the second space S2in the second sub-pixels102(S1<S2). Herein, the line width indicates a width of each of the branch portions, and the line space indicates a space or distance between each adjacent two of the branch portions.

Referring toFIG. 4,FIG. 4is a schematic diagram showing a relationship between a line width/space of the branch portions of one pixel and a corresponding LC efficiency of the liquid crystal display panel according to one embodiment of the present invention. As shown inFIG. 4, a line A indicates a relationship between different spaces and corresponding LC efficiency when the branch portions have a line width of 1 μm, and a line B indicates a relationship between different spaces and corresponding LC efficiency when the branch portions have a line width of 2 μm, and a line C indicates a relationship between different spaces and corresponding LC efficiency when the branch portions have a line width of 3 μm. Accordingly, as shown inFIG. 4, the larger the space between the branch portions of the pixels is, the lower the LC efficiency is.

When images are displayed by the pixels124of the liquid crystal display panel100, a first voltage V1 is applied to the pixel electrodes of the first sub-pixels101, and a second voltage V2 is applied to the pixel electrodes of the second sub-pixels102, and the first voltage V1 is higher than the second voltage V2 (V1>V2). In this case, a voltage difference (V1-V2) between the first voltage V1 and the second voltage V2 is inversely proportional to a grayscale of the images displayed by the pixels124. Therefore, the lower the grayscale (or brightness) of the images displayed by the pixels124is, the larger the voltage difference (V1-V2) between the first sub-pixels101and the second sub-pixels102is. On the contrary, the higher the grayscale (or brightness) of the images displayed by the pixels124is, the less the voltage difference (V1-V2) between the first sub-pixels101and the second sub-pixels102is.

Therefore, in a normally black mode, when the images displayed by the pixels124have a low brightness (or grayscale), the voltage difference (V1-V2) between the first sub-pixels101and the second sub-pixels102in the pixels124can be getting larger, so as to enlarge a brightness difference between the first sub-pixels101and the second sub-pixels102for mitigating the viewing angle problem, as well as improving the display quality thereof. Herein, the viewing angle problem means that the displayed image effects differ between when the display is viewed from the front and when display is viewed obliquely.

Furthermore, the first space S1in the first sub-pixels101can be less than the second space S2in the second sub-pixels102(S1<S2), and thus an LC efficiency of the first sub-pixels101can be higher than an LC efficiency of the second sub-pixels102. In other words, a display brightness of the first sub-pixels101can he higher than a display brightness of the second sub-pixels102. Therefore, with the use of the different electrode spaces in the different sub-pixels of the pixels124, the brightness difference between the first sub-pixels101and the second sub-pixels102can be further enlarged for further mitigating the viewing angle problem of the pixels.

In one embodiment, the space S1or S2between the first branch portions104or the second branch portions106may be less than 7 um, such as in the range of 1 um to 7 um, and a difference (S1-S2) between the first space S1and the second space S2may be larger than 1 um, such as in the range of 1 um to 3 um, so as to mitigate the viewing angle problem of the pixels.

In one embodiment, when the images displayed by the pixels124have a low brightness (or grayscale), i.e. the brightness of the images displayed by the pixels124is lower than a predetermined, brightness, the voltage difference (V1−V2) between the first sub-pixels101and the second sub-pixels102can he larger than 1V, such as in the range of 1V to 3V, so as to mitigate the viewing angle problem of the pixels.

As described above, in the LCD panel and the display apparatus of the present invention using the same, when the images displayed by the pixels have a low brightness (or grayscale), with the use of the different branch spaces and the different driving voltages of the different sub-pixels in the pixels, the brightness difference between the different sub-pixels can be enlarged, so as to mitigate the viewing angle problem of the pixels.