CN110824739B - Display panel, control method and display device - Google Patents

Abstract

The invention discloses a display panel, which comprises a first liquid crystal and a second liquid crystal box, wherein the first liquid crystal box comprises a first substrate, a second substrate and a first liquid crystal layer, the second liquid crystal box comprises a third substrate, a fourth substrate and a second liquid crystal layer, a first polaroid is arranged on the first substrate, a second polaroid with the polarization direction perpendicular to that of the first polaroid is arranged on the second substrate or the third substrate, a third polaroid with the polarization direction parallel to that of the second polaroid is arranged on the fourth substrate, a planar first common electrode, a first pixel electrode and a viewing angle control electrode for controlling a viewing angle are arranged on the fourth substrate, the first pixel electrode is a comb-shaped electrode, the viewing angle control electrode is a planar electrode, an auxiliary electrode matched with the viewing angle control electrode is arranged on the third substrate, and the second liquid crystal layer adopts positive liquid crystal. The invention can realize local dimming and improve the contrast, and can realize the visual angle switching when realizing the local dimming. The invention also discloses a control method and a display device.

Description

Display panel, control method and display device

Technical Field

The invention relates to the technical field of liquid crystal display, in particular to a display panel, a control method and a display device.

Background

Energy saving and image quality improvement are fields in which the color television industry continuously pursues innovation, and with the popularization of liquid crystal televisions, a Local Dimming technology (Local Dimming) is one of the best technologies integrating energy saving and image quality improvement. The LCD tv Display part mainly includes a backlight source and an LCD Panel (Liquid Crystal Display Panel, abbreviated as LCD), and the backlight source of the LCD tv is the largest part of the energy consumption of the whole tv, and the energy saving and image quality improvement can be achieved by adjusting the backlight brightness in various ways. The existing backlight source comprises an edge-in type backlight source and a direct type backlight source, wherein the edge-in type backlight source can enable the backlight to show overall brightness and darkness change by integrally adjusting the brightness of an LED lamp on the backlight source; the direct type backlight source can adjust the brightness of the LED lamps on the backlight source in different areas to realize the adjustment of the brightness of the areas on the backlight source, so that the liquid crystal display screen achieves the purposes of higher contrast (such as 1200: 1) and energy conservation.

With the increasing popularization of HDR (high-dynamic range) technology and the development of technology, people can improve the dynamic contrast of liquid crystal display, so that the conventional contrast ratio of liquid crystal display is only 1000:1 and can reach 10000: contrast of 1 and even 400000:1, Local Dimming (Local Dimming) was followed by the screen overlay technique proposed by the latest Hisense. Although the Local Dimming technique (BL) using backlight (Back light) can further improve the contrast ratio on the original basis, the BL design is complicated, and the accurate control of the pixel level brightness cannot be achieved.

In addition, the current display device gradually develops towards a wide viewing angle, and no matter the application of the mobile terminal of the mobile phone, the desktop display or the notebook computer, besides the requirement of the wide viewing angle, in many occasions, the display device is required to have a function of switching between the wide viewing angle and the narrow viewing angle. Therefore, there is a need for a display panel that has a simple local dimming technique and can switch between wide and narrow viewing angles.

Disclosure of Invention

In order to overcome the disadvantages and shortcomings in the prior art, the present invention provides a display panel, a control method and a display device, so as to solve the problems that the local dimming technology is complex and the switching of the wide and narrow viewing angles cannot be realized while the local dimming technology is satisfied in the prior art.

The purpose of the invention is realized by the following technical scheme:

the invention provides a display panel, which comprises a first liquid crystal box and a second liquid crystal box overlapped with the first liquid crystal box, wherein the first liquid crystal box comprises a first substrate, a second substrate arranged opposite to the first substrate and a first liquid crystal layer positioned between the first substrate and the second substrate, the second liquid crystal box comprises a third substrate, a fourth substrate arranged opposite to the third substrate and a second liquid crystal layer positioned between the third substrate and the fourth substrate, the first substrate is a color film substrate, the second substrate and the fourth substrate are both array substrates, a first polaroid is arranged on the first substrate, a second polaroid with the polarization direction perpendicular to that of the first polaroid is arranged on the second substrate or the third substrate, a third polaroid with the polarization direction parallel to that of the second polaroid is arranged on the fourth substrate, a planar first common electrode is arranged on the fourth polaroid, The first pixel electrode is a comb electrode with a slit, the viewing angle control electrode is a planar electrode, the third substrate is provided with an auxiliary electrode matched with the viewing angle control electrode, the second liquid crystal layer adopts positive liquid crystal, the positive liquid crystal is parallel to the third substrate and the fourth substrate for alignment, and the long axis of the positive liquid crystal is parallel to the polarization direction of the second polaroid.

Furthermore, a plurality of first scan lines, a plurality of first data lines and a plurality of first thin film transistors are disposed on the fourth substrate, the first pixel electrode is electrically connected to the first scan lines and the first data lines adjacent to the first thin film transistors through the first thin film transistors, a plurality of pixel units defined by a plurality of second scan lines and a plurality of second data lines in an insulated and crossed manner are disposed on the second substrate, a second thin film transistor and a second pixel electrode are disposed in each pixel unit, the second pixel electrode is electrically connected to the second scan lines and the second data lines adjacent to the second thin film transistors through the second thin film transistors, and the first scan lines and the second scan lines, the first data lines and the second data lines, and the first pixel electrodes and the second pixel electrodes are vertically aligned.

Furthermore, each first pixel electrode corresponds to one second pixel electrode, and each viewing angle control electrode corresponds to at least one second pixel electrode.

Furthermore, each viewing angle control electrode corresponds to three second pixel electrodes arranged along the scanning line direction, a plurality of touch control wires arranged in parallel with the first data lines are further arranged on the fourth substrate, the viewing angle control electrodes are electrically connected with the first scanning lines and the first data lines adjacent to the first thin film transistors through the first thin film transistors, and every three first data lines and every one touch control wire are arranged periodically.

Furthermore, each viewing angle control electrode corresponds to one second pixel electrode, a plurality of touch control wires arranged in parallel with the first data lines are further arranged on the fourth substrate, the viewing angle control electrodes are electrically connected with the first scanning lines and the first data lines adjacent to the first thin film transistors through the first thin film transistors, and the first data lines and the touch control wires are alternately arranged.

Furthermore, the auxiliary electrode and the first common electrode are both planar electrodes, and the first pixel electrode and the first common electrode are located at different layers.

Further, the auxiliary electrode is a planar electrode corresponding to a row of the viewing angle control electrodes, the first common electrode is a planar electrode corresponding to a plurality of rows of the first pixel electrodes, and the first pixel electrodes and the first common electrode are located at different layers.

The present invention also provides a control method of controlling the display panel as described above, the control method comprising:

receiving image data;

analyzing and processing the image data according to whether the local dimming mode is turned on or not, and then applying corresponding voltage signals to the first pixel electrode and the second pixel electrode;

and applying a corresponding voltage signal on the viewing angle control electrode according to the wide viewing angle mode or the narrow viewing angle mode.

Further, the control method specifically comprises the following steps:

applying the same common voltage signal to the auxiliary electrode, the first common electrode and the second common electrode;

when the local dimming mode is turned off, a first voltage signal is applied to each first pixel electrode, so that the voltage difference between the first pixel electrode and the first common electrode is smaller than a first preset value, and a corresponding gray scale voltage is applied to the second pixel electrode;

when the local dimming mode is switched on, applying respective corresponding voltage signals to the first pixel electrodes to enable respective voltage differences between the first pixel electrodes and the first common electrode to be corresponding, and applying corresponding gray scale voltages to the second pixel electrodes;

when the wide view angle mode is performed, a second voltage signal is applied to the view angle control electrode, so that the voltage difference between the view angle control electrode and the auxiliary electrode is zero or greater than a second preset value;

when in the narrow viewing angle mode, a third voltage signal is applied to the viewing angle control electrode, so that the voltage difference between the viewing angle control electrode and the auxiliary electrode is between zero and the second preset value;

the local dimming mode can be combined with the wide view mode or the narrow view mode.

The invention also provides a display device comprising the display panel.

The invention has the beneficial effects that: when the regional dimming mode is switched on, a corresponding voltage signal is applied to the first pixel electrode and forms a deflection electric field with the first common electrode, so that positive liquid crystal deflects and is matched with the second pixel electrode of the first liquid crystal box, the light transmission characteristics of the first liquid crystal layer and the second liquid crystal layer are mutually compensated, and therefore picture display is achieved to increase contrast and improve texture of a display picture. According to the invention, the wide and narrow visual angles can be switched when the local dimming mode is switched on, the local dimming mode and the wide and narrow visual angle switching are not affected mutually, and both the local dimming mode and the wide and narrow visual angle switching are realized through the second liquid crystal box, so that the structure is simple, the first liquid crystal box can be any liquid crystal box, and the practicability is higher.

Drawings

Fig. 1 is a schematic plan view illustrating a second substrate according to a first embodiment of the invention;

fig. 2 is a schematic plan view illustrating a fourth substrate according to a first embodiment of the invention;

fig. 3 is a schematic structural diagram of a display panel in a local dimming mode of the display panel according to the first embodiment of the invention;

fig. 4 is a schematic structural diagram of a display panel in a local dimming mode according to an embodiment of the invention;

fig. 5 is a second schematic structural diagram of the display panel in the first embodiment of the invention when the local dimming mode is turned on and the viewing angle is wide;

fig. 6 is a schematic structural diagram of a display panel in a local dimming mode of the display panel according to a first embodiment of the present invention;

fig. 7 is a schematic structural diagram of a display panel in a local dimming mode of an embodiment of the invention when the display panel is turned on and has a narrow viewing angle;

fig. 8 is a schematic structural diagram of a display panel in a second embodiment of the invention when the local dimming mode is on and the viewing angle is narrow;

fig. 9 is a schematic plan view illustrating a fourth substrate according to a third embodiment of the present invention;

fig. 10 is a schematic structural diagram of a display panel in a third embodiment of the invention when the local dimming mode is on and the viewing angle is narrow;

FIG. 11 is a schematic diagram of a control method in the present invention;

FIG. 12 is a schematic diagram of viewing angle and brightness of a display panel in a wide and narrow viewing angle mode.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, features and effects of the display panel, the control method and the display device according to the present invention with reference to the accompanying drawings and the preferred embodiments is as follows:

[ example one ]

Fig. 1 is a schematic plan structure diagram of a second substrate in a first embodiment of the present invention, fig. 2 is a schematic plan structure diagram of a fourth substrate in a first embodiment of the present invention, fig. 3 is a schematic plan structure diagram of a display panel in a first embodiment of the present invention when a local dimming mode is turned off and a wide viewing angle is provided, fig. 4 is a schematic plan structure diagram of a display panel in a first embodiment of the present invention when a local dimming mode is turned on and a wide viewing angle is provided, fig. 5 is a second schematic plan structure diagram of a display panel in a first embodiment of the present invention when a local dimming mode is turned on and a wide viewing angle is provided, fig. 6 is a schematic plan structure diagram of a display panel in a first embodiment of the present invention when a local dimming mode is turned off and a narrow viewing angle is provided, and fig. 7 is a schematic plan structure diagram of a display panel in a first embodiment of the present invention when a local dimming mode is turned on and a narrow viewing angle is provided.

As shown in fig. 1 to 7, a display panel according to a first embodiment of the present invention includes a first liquid crystal cell and a second liquid crystal cell overlapping the first liquid crystal cell, the first liquid crystal cell includes a first substrate 10, a second substrate 20 opposite to the first substrate 10, and a first liquid crystal layer 30 between the first substrate 10 and the second substrate 20, and the second liquid crystal cell includes a third substrate 40, a fourth substrate 50 opposite to the third substrate 40, and a second liquid crystal layer 60 between the third substrate 40 and the fourth substrate 50. The first substrate 10 is a color film substrate, the second substrate 20 and the fourth substrate 50 are both array substrates, and the third substrate 40 is a transparent substrate, i.e., no color resists need to be arranged.

The first substrate 10 is provided with a first polarizing plate 71, the second substrate 20 or the third substrate 40 is provided with a second polarizing plate 72 having a polarization direction perpendicular to the first polarizing plate 71, and the fourth substrate 50 is provided with a third polarizing plate 73 having a polarization direction parallel to the second polarizing plate 72. Preferably, the first polarizing plate 71 is located on the side of the first substrate 10 away from the first liquid crystal layer 30, the second polarizing plate 72 is located between the second substrate 20 and the third substrate 40, and the third polarizing plate 73 is located on the side of the fourth substrate 50 away from the second liquid crystal layer 60. Of course, in other embodiments, the second substrate 20 and the third substrate 40 may be combined into one substrate, and the second polarizer 72 may be positioned on either side of the substrate (i.e., the side facing the first liquid crystal layer 30, or the side facing the second liquid crystal layer 60).

The fourth substrate 50 is provided with a planar first common electrode 52, a first pixel electrode 54 matched with the first common electrode 52, and a viewing angle control electrode 55 for controlling a viewing angle, the first pixel electrode 54 is a comb-shaped electrode with a slit, the viewing angle control electrode 55 is a planar electrode, and the viewing angle control electrode 55 and the first pixel electrode 54 are located on the same layer and formed by etching the same metal film. The third substrate 40 is provided with an auxiliary electrode 42 cooperating with the viewing angle control electrode 55, the second liquid crystal layer 60 is made of a positive liquid crystal aligned parallel to the third substrate 40 and the fourth substrate 50, and the long axis of the positive liquid crystal is parallel to the polarization direction of the second polarizer 72, i.e., the long axis of the positive liquid crystal is parallel to the transmission axis of the second polarizer 72. In practical applications, the initial pretilt angle of the positive liquid crystal in the second liquid crystal layer 60 is between 1 ° and 7 ° with respect to the third substrate 40 and the fourth substrate 50, and the positive liquid crystal can be accelerated to be deflected toward the vertical direction at a narrow viewing angle. The alignment direction of the positive liquid crystal on the side close to the third substrate 40 and the alignment direction on the side close to the fourth substrate 50 are parallel or antiparallel to each other. The auxiliary electrode 42 and the first common electrode 52 are planar electrodes arranged on the whole surface, when the local dimming mode is turned on, the first pixel electrode 54 not only forms a horizontal electric field with the first common electrode 52, but also forms a vertical electric field with a certain intensity with the auxiliary electrode 42, but because the horizontal electric field received by the positive liquid crystal is much larger than the vertical electric field, the positive liquid crystal is cut at a certain angle along the vertical electric field direction and horizontally rotates along the horizontal electric field direction, so that the dimming effect is achieved.

As shown in fig. 2 and 3, a plurality of first scan lines 501, a plurality of first data lines 502, and a plurality of first thin film transistors 503 are disposed on the fourth substrate 50, the plurality of first scan lines 501 and the plurality of first data lines 502 are mutually cross-insulated, and the first pixel electrode 54 is electrically connected to the first scan lines 501 and the first data lines 502 adjacent to the first thin film transistors 503 through the first thin film transistors 503. The first data line 502 is insulated and isolated from the first common electrode 52 by the first planarization layer 51, the first pixel electrode 54 is located at a different layer from the first common electrode 52 and is insulated and isolated by the first insulation layer 53, and the first thin film transistor 503 includes a gate electrode, an active layer, a drain electrode, and a source electrode.

Each of the first pixel electrodes 54 corresponds to one of the second pixel electrodes 24, and each of the viewing angle control electrodes 55 corresponds to at least one of the second pixel electrodes 24. In this embodiment, each viewing angle control electrode 55 corresponds to three second pixel electrodes 24 arranged along the direction of the scan line, that is, each viewing angle control electrode 55 corresponds to one pixel (including three sub-pixels of red, green and blue) of the display panel. The fourth substrate 50 is further provided with a plurality of touch traces 504 arranged in parallel with the first data lines 502, the viewing angle control electrodes 55 are electrically connected with the first scan lines 501 and the first data lines 502 adjacent to the first thin film transistors 503 through the first thin film transistors 503, every three first data lines 502 and one touch trace 504 are arranged periodically, and each viewing angle control electrode 55 can independently control the corresponding pixel to realize wide and narrow viewing angle switching. Of course, in other embodiments, the viewing angle control electrode 55 may correspond to three rows of the second pixel electrodes 24, i.e., three rows of pixels, and then the plurality of viewing angle control electrodes 55 are electrically connected in the non-display region to integrally control the wide and narrow viewing angle switching, but not limited thereto.

As shown in fig. 1, a plurality of pixel units SP defined by a plurality of second scan lines 201 and a plurality of second data lines 202 crossing each other in an insulated manner are disposed on the second substrate 20, a second thin film transistor 203 and a second pixel electrode 24 are disposed in each pixel unit SP, and the second pixel electrode 24 is electrically connected to the second scan lines 201 and the second data lines 202 adjacent to the second thin film transistor 203 through the second thin film transistor 203. The first scan line 501 and the second scan line 201, the first data line 502 and the second data line 202, the touch trace 504 and the second data line 202, and the first pixel electrode 54 and the second pixel electrode 24 are all aligned up and down, that is, the first scan line 501 and the second scan line 201 correspond one by one, one first data line 502 corresponds to one second data line 202, one touch trace 504 corresponds to one second data line 202, and one first pixel electrode 54 corresponds to one second pixel electrode 24 (one first pixel electrode 54 corresponds to one sub-pixel).

In this embodiment, the second pixel electrode 24 and the second common electrode 22 are located at different layers, the second common electrode 22 may be located above or below the second pixel electrode 24 (the second common electrode 22 is located below the second pixel electrode 24 in fig. 3), preferably, the second common electrode 22 is a planar electrode disposed on the whole surface, the second pixel electrode 24 is a block electrode disposed in a whole block in each pixel unit SP or a slit electrode having a plurality of electrode bars to form a Fringe Field Switching (FFS) mode, the second common electrode 22 is insulated and isolated from the second data line 202 by the second planarization layer 21, and the second common electrode 22 is insulated and isolated from the second pixel electrode 24 by the second insulation layer 23. Of course, In other embodiments, the second pixel electrode 24 and the second common electrode 22 may be located on the same layer, but they are insulated and isolated from each other, each of the second pixel electrode 24 and the second common electrode 22 may include a plurality of electrode stripes, and the electrode stripes of the second pixel electrode 24 and the electrode stripes of the second common electrode 22 are alternately arranged to form an In-Plane Switching (IPS) mode, which is not limited thereto. Alternatively, in other embodiments, the first liquid crystal cell may also be a TN display mode or a VA display mode.

As shown in fig. 3, the first substrate 10 is provided with a first black matrix 11, and the plurality of first black matrices 11 correspond to the plurality of scan lines 201 and the plurality of data lines 202. A color resist layer 12 is disposed in a region corresponding to the pixel unit SP on the color filter substrate 10, the color resist layer 12 is spaced apart by a first black matrix 11, the color resist layer 12 includes color resist materials of three colors of red (R), green (G), and blue (B), and sub-pixels of the three colors of red (R), green (G), and blue (B) are correspondingly formed, and certainly, a planarization layer and an alignment layer (not shown) are further disposed on the first substrate 10. The third substrate 40 is provided with a second black matrix 41, and the second black matrix 41 vertically corresponds to the first black matrix 11.

The first substrate 10, the second substrate 20, the third substrate 40, and the fourth substrate 50 may be made of glass, acrylic, polycarbonate, or the like. The material of the common electrode, the pixel electrode, the viewing angle control electrode 55, and the auxiliary electrode 42 may be Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or the like.

[ example two ]

As shown in fig. 8, a display panel according to a second embodiment of the present invention is substantially the same as the display panel according to the first embodiment (fig. 1 to 7), except that in this embodiment, the auxiliary electrode 42 is a planar electrode corresponding to one row of viewing angle control electrodes 55, the first common electrode 52 is a planar electrode corresponding to a plurality of rows of first pixel electrodes 54, and the first pixel electrodes 54 and the first common electrode 52 are located at different layers. That is, the auxiliary electrode 42 and the first common electrode 52 are not planar electrodes, but are strip-shaped electrodes corresponding to the auxiliary electrode 42 and one row of viewing angle control electrodes 55, but are absent in the area of the first pixel electrode 54, the first common electrode 52 and the strip-shaped electrodes corresponding to the plurality of rows of the first pixel electrodes 54 are absent in the area of the viewing angle control electrodes 55, the plurality of auxiliary electrodes 42 are electrically connected in the non-display area and apply the same voltage signal, and the plurality of first common electrodes 52 are electrically connected in the non-display area and apply the same voltage signal.

In contrast to the first embodiment, the present embodiment can avoid a certain interference to the local dimming mode due to the vertical electric field formed between the first pixel electrode 54 and the auxiliary electrode 42, and meanwhile, avoid a certain interference to the view angle switching due to the horizontal electric field formed between the view angle control electrode 55 and the first common electrode 52.

It should be understood by those skilled in the art that the rest of the structure and the operation principle of the present embodiment are the same as those of the first embodiment, and are not described herein again.

[ third example ]

As shown in fig. 9 and 10, a display panel provided in the third embodiment of the present invention is substantially the same as the display panel provided in the first embodiment (fig. 1 to 7), except that in the present embodiment, each viewing angle control electrode 55 corresponds to one second pixel electrode 24, that is, each viewing angle control electrode 55 corresponds to one sub-pixel, a plurality of touch traces 504 arranged in parallel with the first data lines 502 are further disposed on the fourth substrate 50, the viewing angle control electrodes 55 are electrically connected to the first scan lines 501 and the first data lines 502 adjacent to the first thin film transistors 503 through the first thin film transistors 503, and the first data lines 502 and the touch traces 504 are alternately arranged.

Compared with the first embodiment, the viewing angle control electrode 55 and the second pixel electrode 24 are distributed more uniformly on the fourth substrate 50, and the image quality displayed in the local dimming mode and the narrow viewing angle mode is better.

It should be understood by those skilled in the art that the rest of the structure and the operation principle of the present embodiment are the same as those of the first embodiment, and are not described herein again.

As shown in fig. 11, the present invention also provides a control method of controlling the display panel as described above, the control method including:

step 1: receiving image data;

step 2: analyzing and processing the image data according to whether the local dimming mode is turned on, converting the processed image data into electrical information, and then applying corresponding voltage signals to the first and second pixel electrodes 54 and 24;

and step 3: a corresponding voltage signal is applied to the viewing angle control electrode 55 according to the wide viewing angle mode or the narrow viewing angle mode. Of course, step 2 and step 3 may be in the same order.

The auxiliary electrode 42, the first common electrode 52, and the second common electrode 22 are all applied with the same common voltage signal at any time, that is, the auxiliary electrode 42, the first common electrode 52, and the second common electrode 22 are all applied with the same common voltage signal after being turned on from the display panel.

Specifically, when the local dimming mode is turned off, as shown in fig. 3 and 6, a first voltage signal is applied to each first pixel electrode 54, so that a voltage difference between the first pixel electrode 54 and the first common electrode 52 is smaller than a first preset value (0.1V), and preferably, no voltage is applied to the first pixel electrode 54, so that a voltage difference between the first pixel electrode 54 and the first common electrode 52 is zero. The second pixel electrode 24 is applied with corresponding gray scale voltage and forms a voltage difference with the second common electrode 22, that is, the second pixel electrode 24 is applied with gray scale voltage between 0 and 255 to display a normal picture;

when the local dimming mode is turned on, as shown in fig. 4, 5 and 7, a corresponding voltage signal is applied to each first pixel electrode 54, for example, a voltage signal matched with the gray scale voltage on the second pixel electrode 24 is applied to make a corresponding voltage difference between each first pixel electrode 54 and the first common electrode 52, the second liquid crystal layer 60 corresponding to the first pixel electrode 54 deflects at different angles, so that light passing through the second liquid crystal cell is reduced, a corresponding gray scale voltage is applied to the second pixel electrode 24 and forms a voltage difference with the second common electrode 22, and a normal picture is displayed through the combined action of the first pixel electrode 54 and the second pixel electrode 24. When displaying a black image, the light passing through the display panel is reduced by the cooperation of the first pixel electrode 54 and the second pixel electrode 24, so as to reduce the brightness of the black image, thereby improving the contrast.

When in the wide viewing angle mode, as shown in fig. 3 to 5, the viewing angle second voltage signal on the viewing angle control electrode 55 makes the voltage difference between the viewing angle control electrode 55 and the auxiliary electrode 42 zero, i.e. no voltage or the same voltage as the auxiliary electrode 42 is applied to the viewing angle control electrode 55, and the second liquid crystal layer 60 corresponding to the viewing angle control electrode 55 is not substantially deflected (fig. 3 and 4), or the voltage difference between the viewing angle control electrode 55 and the auxiliary electrode 42 is greater than a second preset value (e.g. 3V), and the second liquid crystal layer 60 corresponding to the viewing angle control electrode 55 is deflected to be perpendicular to the third substrate 40 and the fourth substrate 50 (fig. 5), of course, the liquid crystal molecules near the third substrate 40 and the fourth substrate 50 are deflected by a smaller angle in the vertical direction due to the alignment force. After passing through the second liquid crystal layer 60, the polarization state of the light is not changed, and then the light passes through the first liquid crystal box, so that the conventional wide-viewing-angle display is realized;

when in the narrow viewing angle mode, as shown in fig. 6 and 7, the third voltage signal of the viewing angle on the viewing angle control electrode 55 makes the voltage difference between the viewing angle control electrode 55 and the auxiliary electrode 42 between zero and the second preset value, so that the second liquid crystal layer 60 corresponding to the viewing angle control electrode 55 is tilted, and after the light passes through the second liquid crystal layer 60, the phase delay of the large viewing angle is large, so that the non-vertical light or the light with a large tilt angle is absorbed by the second polarizer 72, thereby presenting the light receiving mode, and the light with the large viewing angle, such as 45 degrees later, is cut down, so that the brightness of the large viewing angle is reduced, and the brightness is dark, so that the display content cannot be seen by human eyes, thereby implementing the narrow viewing angle mode.

As shown in fig. 12, the abscissa is the viewing angle, the ordinate is the luminance, in the wide viewing angle mode, as curve a, 0V or 5V is applied to the viewing angle control electrode 55, and the viewing angle range is 85 °, in the narrow viewing angle mode, as curve b, 2V is applied to the viewing angle control electrode 55, and the viewing angle range is 45 °, and after the viewing angle is 45 °, the luminance is greatly reduced, and it is difficult to see the picture, and by reducing the luminance of the large viewing angle, the problem of gray scale inversion can be avoided, and in the normal view (viewing angle is 0 °), the luminance of the narrow viewing angle mode is substantially the same as that of the wide viewing angle mode.

The local dimming mode can be combined with the wide viewing angle mode or the narrow viewing angle mode, that is, when the local dimming mode is turned off, the viewing angle of the display panel can be in the wide viewing angle mode (fig. 3) or in the narrow viewing angle mode (fig. 6), and when the local dimming mode is started, the viewing angle of the display panel can be in the wide viewing angle mode (fig. 4 and 5) or in the narrow viewing angle mode (fig. 7).

In summary, the second pixel electrode 24 of the first liquid crystal cell and the first pixel electrode 54 of the second liquid crystal cell are matched with each other, so that the light transmission characteristics of the first liquid crystal layer 30 and the second liquid crystal layer 60 are compensated with each other, thereby realizing image display to increase contrast, when in the narrow viewing angle mode, a voltage within a preset range is applied to the viewing angle control electrode 55, the positive liquid crystal far away from the third substrate 40 and the fourth substrate 50 in the second liquid crystal layer 60 is greatly deflected, the positive liquid crystal close to the third substrate 40 and the fourth substrate 50 basically keeps an initial pretilt angle, after the light passes through the second liquid crystal layer 60, the phase delay of the large viewing angle is large, so that the non-vertical light or the large light is absorbed by the second polarizer, the brightness of the large viewing angle is reduced, the light receiving mode is presented, and the narrow viewing angle is realized. According to the invention, the wide and narrow visual angles can be switched when the local dimming mode is switched on, the local dimming mode and the wide and narrow visual angle switching are not affected mutually, and both the local dimming mode and the wide and narrow visual angle switching are realized through the second liquid crystal box, namely, the local dimming mode and the wide and narrow visual angle switching are integrated into the second liquid crystal box, the structure is simple, the first liquid crystal box can be any liquid crystal box, and the practicability is higher.

The invention also provides a display device comprising the display panel.

In this document, the terms upper, lower, left, right, front, rear and the like are used for defining the positions of the structures in the drawings and the positions of the structures relative to each other, and are only used for the clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims. It is also to be understood that the terms "first" and "second," etc., are used herein for descriptive purposes only and are not to be construed as limiting in number or order.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A display panel comprises a first liquid crystal box and a second liquid crystal box overlapped with the first liquid crystal box, wherein the first liquid crystal box comprises a first substrate (10), a second substrate (20) arranged opposite to the first substrate (10) and a first liquid crystal layer (30) arranged between the first substrate (10) and the second substrate (20), the second liquid crystal box comprises a third substrate (40), a fourth substrate (50) arranged opposite to the third substrate (40) and a second liquid crystal layer (60) arranged between the third substrate (40) and the fourth substrate (50), the display panel is characterized in that the first substrate (10) is a color film substrate, the second substrate (20) and the fourth substrate (50) are both array substrates, a first polarizer (71) is arranged on the first substrate (10), and a second polarizer (72) with the polarization direction perpendicular to the first polarizer (71) is arranged on the second substrate (20) or the third substrate (40), a third polaroid (73) with the polarization direction parallel to the second polaroid (72) is arranged on the fourth substrate (50), a planar first common electrode (52), a first pixel electrode (54) matched with the first common electrode (52) and a visual angle control electrode (55) for controlling the visual angle are arranged on the fourth substrate (50), the first pixel electrode (54) is a comb-shaped electrode with a slit, the visual angle control electrode (55) is a planar electrode, an auxiliary electrode (42) matched with the visual angle control electrode (55) is arranged on the third substrate (40), the second liquid crystal layer (60) adopts positive liquid crystal, the positive liquid crystal is aligned parallel to the third substrate (40) and the fourth substrate (50), the long axis of the positive liquid crystal is parallel to the polarization direction of the second polaroid (72), the first liquid crystal box comprises a plurality of pixel units (SP), the first pixel electrode (54) and the viewing angle control electrode (55) correspond to different pixel units (SP), respectively.

2. The display panel according to claim 1, wherein the fourth substrate (50) is provided with a plurality of first scan lines (501), a plurality of first data lines (502), and a plurality of first TFTs (503), the first pixel electrode (54) is electrically connected to the first scan lines (501) and the first data lines (502) adjacent to the first TFTs (503) through the first TFTs (503), the second substrate (20) is provided with a plurality of second scan lines (201) and a plurality of second data lines (202) which are insulated from each other and crossed to define a plurality of pixel units (SP), each pixel unit (SP) is provided with a second TFT (203) and a second pixel electrode (24), the second pixel electrode (24) is electrically connected to the second scan lines (201) and the second data lines (202) adjacent to the second TFTs (203) through the second TFTs (203), the first scan line (501) and the second scan line (201), the first data line (502) and the second data line (202), and the first pixel electrode (54) and the second pixel electrode (24) are all aligned up and down.

3. The display panel according to claim 2, wherein each first pixel electrode (54) corresponds to one second pixel electrode (24), and each viewing angle control electrode (55) corresponds to at least one second pixel electrode (24).

4. The display panel according to claim 3, wherein each viewing angle control electrode (55) corresponds to three second pixel electrodes (24) arranged along a scan line direction, a plurality of touch traces (504) arranged in parallel with the first data lines (502) are further disposed on the fourth substrate (50), the viewing angle control electrode (55) is electrically connected to the first scan lines (501) and the first data lines (502) adjacent to the first thin film transistors (503) through the first thin film transistors (503), and every three first data lines (502) and one touch trace (504) are arranged periodically.

5. The display panel according to claim 3, wherein each viewing angle control electrode (55) corresponds to one of the second pixel electrodes (24), the fourth substrate (50) further has a plurality of touch traces (504) arranged in parallel with the first data lines (502), the viewing angle control electrodes (55) are electrically connected to the first scan lines (501) and the first data lines (502) adjacent to the first thin film transistors (503) through the first thin film transistors (503), and the first data lines (502) and the touch traces (504) are alternately arranged.

6. The display panel according to claim 1, wherein the auxiliary electrode (42) and the first common electrode (52) are planar electrodes, and the first pixel electrode (54) and the first common electrode (52) are located at different layers.

7. The display panel according to claim 1, wherein the auxiliary electrode (42) is a planar electrode corresponding to one row of the viewing angle control electrodes (55), the first common electrode (52) is a planar electrode corresponding to a plurality of rows of the first pixel electrodes (54), and the first pixel electrodes (54) and the first common electrode (52) are located at different layers.

8. A control method of controlling the display panel according to any one of claims 1 to 7, characterized in that the control method comprises:

receiving image data;

analyzing and processing the image data according to whether the local dimming mode is on, and then applying corresponding voltage signals on the first pixel electrode (54) and the second pixel electrode (24);

a corresponding voltage signal is applied on the viewing angle control electrode (55) according to the wide viewing angle mode or the narrow viewing angle mode.

9. The control method according to claim 8, characterized in that the control method is specifically:

applying the same common voltage signal on the auxiliary electrode (42), the first common electrode (52) and the second common electrode (22);

when the local dimming mode is turned off, a first voltage signal is applied to each first pixel electrode (54), so that the voltage difference between the first pixel electrode (54) and the first common electrode (52) is smaller than a first preset value, and a corresponding gray scale voltage is applied to the second pixel electrode (24);

when the local dimming mode is turned on, applying a corresponding voltage signal to each first pixel electrode (54), so that a corresponding voltage difference is generated between each first pixel electrode (54) and the first common electrode (52), and a corresponding gray scale voltage is applied to the second pixel electrode (24);

when in the wide view angle mode, a second voltage signal is applied to the view angle control electrode (55) to make the voltage difference between the view angle control electrode (55) and the auxiliary electrode (42) be zero or greater than a second preset value;

when in the narrow viewing angle mode, a third voltage signal is applied to the viewing angle control electrode (55) to make the voltage difference between the viewing angle control electrode (55) and the auxiliary electrode (42) between zero and the second preset value;

the local dimming mode can be combined with the wide view mode or the narrow view mode.

10. A display device characterized by comprising the display panel according to any one of claims 1 to 7.

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