Patent Description:
The liquid crystal display (LCD) device must rely on the backlight module to provide backlight to make the LCD device display image because the LCD panel does not illuminate.

As shown in <FIG>, an LCD device of the known technology includes an LCD panel <NUM>, an upper polarizer <NUM> and a lower polarizer <NUM> located respectively on the upper and lower surfaces of the LCD panel <NUM>, and a backlight module <NUM> located at a side of the lower polarizer <NUM> away from the LCD panel <NUM>; wherein, the LCD panel <NUM> includes an array substrate <NUM>, a color film (CF) substrate <NUM>, and a liquid crystal (LC) layer <NUM> sandwiched between the array substrate <NUM> and the CF substrate <NUM>.

The known LCD device often suffers light leakage when displaying dark state. For example, a part of the light emitted from the backlight source <NUM> of the LCD device is unable to enter the LCD panel <NUM> at a perpendicular angle, and this part of light, after polarized by the lower polarizer <NUM>, forms an incident angle with the optical axis of LC molecules in the LC layer <NUM> to enter the LC layer <NUM>; wherein, for the LC molecules of the LCD panel <NUM>, when the LCD device is in dark state displaying, the optical axis is perpendicular to the LCD panel <NUM>. Because of the birefringence property of the LC molecules, this part of light incident to the LC layer <NUM> with an angle will experience birefringence effect and become elliptically polarized light. When the light reaches the upper polarizer <NUM>, the light cannot be completely absorb, resulting in light leakage phenomenon when the LCD device displaying the dark state and further restricting the improvement of the contrast. <CIT> and <CIT> are related prior art in this field. Specifically, <CIT> is related to reducing a step difference of a black matrix and preventing deterioration of fluidity of a liquid crystal and reducing deterioration of a shock absorbing property of a display panel. <CIT> is related to reducing a source-drain parasitic capacitance between a pixel electrode and a source bus line by providing a shield electrode.

The primary object of the present invention is to provide an LCD panel, able to improve light leakage in dark state and enhance display performance.

The present invention provides a liquid crystal display (LCD) panel as recited in appended independent claim <NUM>. Other aspects of the invention are recited in the appended dependent claims.

Compared to the known techniques, the present disposes a first electrode layer at the side of the first substrate adjacent to the LC layer, with the first electrode layer corresponding to the sub-pixel areas and the shielding areas, and mutually independent a second electrode layer and a third electrode layer at the side of the second substrate adjacent to the LC layer, with the second electrode layer corresponding to the sub-pixel areas and the third electrode layer corresponding to the shielding areas; wherein, the third electrode disposed with vias. When the LCD panel is in the dark state, the LC molecules between the first and third electrode layers are polarized under the effect of the voltage bias (driving voltage) to achieve the multi-domain division effect, and is filtered out by the orthogonal polarizers of the upper and the lower substrates, so as to improve the problem of light leakage in dark state for the LCD panel.

To make the technical solution of the embodiments according to the present invention, a brief description of the drawings that are necessary for the illustration of the embodiments will be given as follows. Apparently, the drawings described below show only example embodiments of the present invention and for those having ordinary skills in the art, other drawings may be easily obtained from these drawings without paying any creative effort.

To further explain the technical means and effect of the present invention, the following refers to embodiments and drawings for detailed description. Apparently, the described embodiments are merely some embodiments of the present invention, instead of all embodiments. All other embodiments based on embodiments in the present invention and obtained by those skilled in the art without departing from the creative work of the present invention are within the scope of the present invention.

Refer to <FIG> is a cross-sectional view showing the LCD panel of the present invention when not powered on. The LCD panel of the present invention includes: a first substrate <NUM>, a second substrate <NUM>, and an LC layer <NUM>. The LCD panel has an active area disposed with a plurality of sub-pixel areas <NUM> arranged in an array, and shielding areas <NUM> between two adjacent sub-pixel areas <NUM>. The first substrate <NUM> and the second substrate <NUM> are disposed opposite to each other, and the LC layer <NUM> is sandwiched between the first substrate <NUM> and the second substrate <NUM>. Preferably, the LC layer <NUM> includes LC molecules <NUM> with negative dielectric anisotropy, and a plurality of reaction monomers mixed in the LC molecules <NUM>. Wherein, the LC molecules <NUM> are a liquid crystal material with deflection orientation property in a specific direction by applying a driving voltage, and are able to achieve different deflection orientations by a threshold value of the driving voltage applied. When the LCD panel is not applied with a voltage, the LC molecules <NUM> of the LC layer <NUM> are vertically oriented. The reaction monomers are polymerizable monomers, such as, acrylic resin monomer molecules, methacrylate resin monomer molecules, vinyl resin monomer molecules, ethyleneoxy groups Resin monomer molecules, epoxy resin monomer molecules, and any combination of the above.

The side of the first substrate <NUM> adjacent to the LC layer <NUM> is disposed with a first electrode layer <NUM>, and the first electrode layer <NUM> is corresponding to the sub-pixel areas <NUM> and shielding areas <NUM>. The side of the second substrate <NUM> adjacent to the LC layer <NUM> is disposed with a second electrode layer <NUM> and a third electrode layer <NUM>, and the second electrode layer <NUM> and the third electrode layer <NUM> are mutually independent. In other words, the voltages loaded to the second electrode layer <NUM> and the third electrode layer <NUM> can be controlled separately. The second electrode layer <NUM> is corresponding to the sub-pixel areas <NUM> and the third electrode layer <NUM> is corresponding to the shielding areas <NUM>; wherein, the third electrode layer being disposed with vias (not numbered). IN other words, the LC layer <NUM> is between the first electrode layer <NUM> and the second/ third electrode layers <NUM>/<NUM>.

Refer to <FIG> is a cross-sectional view showing the LCD panel of <FIG> when in dark state. When the LCD panel is in the dark state (i.e., powered on), the first electrode layer <NUM> and the third electrode layer <NUM> are powered on, while the second electrode layer <NUM> is cut-off. At this point, because the LC molecules <NUM> between the first electrode layer <NUM> and the second electrode layer <NUM> are not driven by the driving voltage, i.e., the LC molecules <NUM> stay vertical orientation, the sub-pixel areas <NUM> is not light transmissive; both the first electrode layer <NUM> and the third electrode layer <NUM> are loaded with a voltage, and form a certain voltage bias; therefore, the LC molecules <NUM> between the first electrode layer <NUM> and the third electrode layer <NUM> are driven by voltage bias (driving voltage) to deflect orientation. In the mean time, because the third electrode layer <NUM> is disposed with vias, the LC molecules <NUM> near the vias will be under the effect of the boundary electrical field to incline towards the direction away from the vias; i.e., the LC molecules <NUM> in the LC layer <NUM> will have a plurality of inclination directions, resulting in a plurality of domains to achieve multi-domain segmentation effect. When the scattered light passing through the LC molecules <NUM>, the light will pass length axis of the LC molecules <NUM> corresponding to sub-pixel areas <NUM> and the polarized state of the incident light does not change and will be filtered out by the orthogonal polarizers of the upper and lower substrates, thereby improving the light leakage problem in dark state for LCD panel.

In an embodiment of the present invention, the first substrate <NUM> is a color film substrate, and the first electrode layer <NUM> is a common electrode layer; correspondingly, the second substrate <NUM> is an array substrate, and the second electrode layer <NUM> is a pixel electrode layer. Specifically, the second substrate <NUM> may include a glass substrate <NUM> and a color resist layer <NUM> disposed on the glass substrate <NUM>. The color resist layer <NUM> is between the glass substrate <NUM> and the second/third electrode layer <NUM>/<NUM>. It should be noted that the color resist layer <NUM> includes red color resist, green color resist, and blue color resist. The adjacent sub-pixels <NUM> have different color resists. Moreover, the first substrate <NUM> and the second substrate <NUM> are disposed respectively with polarizers (not shown). The polarizer of the first substrate <NUM> and the polarizer of the second substrate <NUM> are mutually perpendicular, i.e., the polarization directions are <NUM>° apart.

Furthermore, in the present embodiment, the data lines provides electricity through the via holes on the second substrate <NUM> (array substrate) to the second electrode layer <NUM> (pixel electrode), and the third electrode layer is supplied with electricity along the peripheral of the second substrate <NUM>.

According to an embodiment of the present invention, the second substrate <NUM> is further disposed with a shielding protrusion element <NUM>, the shielding protrusion element <NUM> corresponds to the shielding areas <NUM>. Specifically, the shielding protrusion element <NUM> is disposed at locations above the junction of adjacent color resists. The third electrode layer <NUM> covers the shielding protrusion element <NUM>. In addition to shielding light, the shielding protrusion element <NUM> also provides the following effect: making the shielding areas <NUM> smaller than sub-pixel areas <NUM> so that the LC molecules <NUM> in the shielding areas <NUM> are easier to incline towards the sub-pixel areas <NUM> under the effect of driving voltage to achieve better effect on filtering scattered light.

Preferably, the shielding protrusion element <NUM> is T-shaped, and has a protrusion part protruding beyond the vias. It should be noted that the space corresponding to the above of the vias is smallest, and the space above the third electrode layer <NUM> as the second, while the space above the second electrode layer <NUM> (corresponding to the sub-pixel areas <NUM>) is the largest. The purpose of such a disposition is to form a deflection trend towards the sub-pixel areas <NUM> for the LC molecules <NUM>. The LC molecules <NUM> corresponding to the location of the vias deflects towards outside of the vias (the area corresponding to the third electrode) under the effect of boundary electrical field. The LC molecules <NUM> corresponding to the third electrode layer <NUM> will deflect towards the sub-pixel areas <NUM> to achieve better effect on filtering scattered light.

Specifically, refer to <FIG> is a schematic view showing the structure of the third electrode layer according to an embodiment of the present invention. The third electrode layer <NUM> includes a plurality of stripe electrodes <NUM> arranged with space apart, and each stripe electrode <NUM> is disposed with a plurality of vias <NUM>. The plurality of stripe electrodes <NUM> is electrically connected to form an entirety. The stripe electrode <NUM> is formed by extending along the Y direction, wherein X direction is perpendicular to Y direction. Moreover, the shielding protrusion element <NUM> extends along the length direction of the stripe electrodes <NUM>.

It should be noted that in the actual use of the LCD panel, when the light leakages in the X direction and Y direction are compared, the light leakage in the X direction deserves more attention. Refer to <FIG> is a top view showing the inclination of the LC molecules. In the actual design process, it should be ensured that the LC molecules <NUM> are more inclined towards the X direction and less in the Y direction deflection. Thus, the length of the shielding protrusion element <NUM> can be designed as longer in the Y direction than in the X direction. That is, the shielding protrusion element <NUM> extends in the longitudinal direction of the strip electrode <NUM>. It is to be understood that the length of the via holes <NUM> in the strip electrode <NUM> in the Y direction is larger than in the X direction.

Moreover, the first substrate <NUM> is further disposed with a black matrix <NUM>, the black matrix <NUM> corresponds to the shielding areas <NUM>, and the first electrode layer <NUM> covers the black matrix <NUM>. The black matrix <NUM> is between the first substrate <NUM> and the first electrode layer <NUM>. It should be understood that the black matrix <NUM> can further enhance the shielding effect of the LCD panel.

In another embodiment of the present invention, the first substrate <NUM> is an array substrate, and the first electrode layer <NUM> is a pixel electrode layer; correspondingly, the second substrate <NUM> is a color film substrate, and the second electrode layer <NUM> is a common electrode layer. In other words, the third electrode layer <NUM> is disposed on the color film substrate. It should be understood that the first electrode layer <NUM> and the second electrode layer <NUM> are made of transparent conductive material. Furthermore, the first electrode layer <NUM> and the second electrode layer <NUM> can be made of the same material or different materials, such as, indium tin oxide (ITO), indium zinc oxide (IZO), or any other combination of materials having both light transmission and conductivity.

Claim 1:
A liquid crystal display (LCD) panel (<NUM>), wherein the LCD panel (<NUM>) comprises:
a first substrate (<NUM>) and a second substrate (<NUM>), disposed opposite to each other, and a vertically aligned liquid crystal (LC) layer (<NUM>) sandwiched between the first substrate (<NUM>) and the second substrate (<NUM>); the LCD panel (<NUM>) having an active area disposed with a plurality of sub-pixel areas (<NUM>) arranged in an array, and shielding areas (<NUM>) between two adjacent sub-pixel areas (<NUM>); a side of the first substrate (<NUM>) adjacent to the LC layer (<NUM>) being disposed with a first electrode layer (<NUM>) and a black matrix (<NUM>),
the first electrode layer (<NUM>) being corresponding to the sub-pixel areas (<NUM>) and shielding areas (<NUM>), the black matrix (<NUM>) being corresponding to the shielding areas (<NUM>); a side of the second substrate (<NUM>) adjacent to the LC layer (<NUM>) being disposed with a second electrode layer (<NUM>) and a third electrode layer (<NUM>), the second electrode layer (<NUM>) and the third electrode layer (<NUM>) being configured to be controlled separately;
the second electrode layer (<NUM>) being corresponding to the sub-pixel areas (<NUM>) and the third electrode layer (<NUM>) being corresponding to the shielding areas (<NUM>); wherein, the third electrode layer (<NUM>) being disposed with vias (<NUM>);
characterized in that the second substrate (<NUM>) is further disposed with a plurality of light shielding protrusion elements (<NUM>), each light shielding protrusion element (<NUM>) corresponds to a shielding area (<NUM>) between two adjacent sub-pixel areas (<NUM>) and the third electrode layer (<NUM>) covers each light shielding protrusion element (<NUM>), wherein each light shielding protrusion element (<NUM>) has a protrusion part forming a T-shape and protruding beyond a respective one of the vias (<NUM>);
wherein the third electrode layer (<NUM>) comprises a plurality of stripe electrodes (<NUM>) arranged with space apart and corresponding to respective shielding areas (<NUM>), and each stripe electrode (<NUM>) is disposed with a plurality of said vias (<NUM>).