Embodiments of the invention relate to an array substrate, a method for controlling the same and a display panel including the array substrate.
Stereoscopic display has become a big trend of the display field. And, the basic principle of the stereoscopic display is to produce a stereoscopy by utilizing a parallax, i.e., a left-eye picture is seen by the left eye of a person, and a right-eye picture is seen by his right eye. Herein, the left-eye and right-eye pictures are a pair of stereoscopic images having the parallax.
One mode to achieve the stereoscopy is a time serial manner, in which at a first time slot, a left-eye picture is displayed on a display and the displayed left-eye picture is only seen by the left eye of a viewer at this time; and at a second time slot, a right-eye picture is displayed on the display and the displayed right-eye picture is only seen by the right eye of the viewer. With persistence of vision of human eyes, a feeling is given to the person that the left-eye and right-eye pictures are simultaneously seen by the left and right eyes, thereby producing a stereoscopic sensation.
Another mode to achieve the stereoscopy is a parallel manner, in which at the same time, content for a left-eye picture is displayed by a part of pixels on a display, and content for a right-eye picture is displayed by another part of pixels. The content displayed by a part of the pixels only can be seen by the right eye and that displayed by another part only can be seen by the left eye by way of gratings, polarization spectacles, etc., so as to produce the stereoscopic sensation.
A polarization spectacles type stereoscopic display is one kind of mainstream technology in the current stereoscopic display field, and the basic constituting manner of the polarization spectacles type stereoscopic display is to install a device capable of adjusting a polarization direction of emitting lights in front of a display panel. The device may be a phase retarder plate, or may also be a liquid crystal cell, or other devices capable of adjusting the polarization directions of emitting lights from different pixels. The principle of a phase retarder plate type stereoscopic display is as shown in FIG. 1, and from top to bottom, there are a picture displayed by the display panel, the phase retarder plate, an emitting picture, and polarization spectacles for viewing. On the display panel, a right-eye picture and a left-eye picture are alternately shown in adjacent rows. The phase retarder plate is disposed in front of the display panel, one row has λ/2 retardation, and adjacent one row has zero retardation. As such, the polarization direction of emitting lights from pixels which correspond to the rows having the λ/2 retardation can be rotated by 90°. In this manner, only lights emitted by right-eye pixels can be seen by the right eye and only lights emitted by left-eye pixels can be seen by the left eye when the person wears polarization spectacles having such polarization directions that are perpendicular to each other for the left and right eyes, so as to produce a stereoscopic effect.
In a variety of stereoscopic displays of the polarization spectacles mode, a technology in which a phase retarder plate is employed takes the most favor. The basic structure of this stereoscopic display is that a phase retarder plate is attached to a display panel after they are precisely aligned. Different phase retardations can be produced with the use of different regions on the phase retarder plate, so that lights from different pixels emit in different polarization directions and a viewer can see a 3D effect when wearing polarization spectacles.
However, one of drawbacks for this 3D display is that the viewing angle in a perpendicular direction is very small (other polarization spectacles mode 3D displays each have this drawback). A simplified principle (in which only simplified, theoretical computation is given, but a directional result can be provided by it) that explains why the viewing angle for the polarization spectacles mode 3D display is narrow is schematically illustrated in FIG. 2, in which, DP is the display panel, and PR is the phase retarder plate. In FIG. 2, a is height of a pixel display area, b is width of a black matrix (BM) in a perpendicular direction, c is width of one stripe of the phase retarder plate, h is distance from the phase retarder plate to the display panel, θ is a 3D viewing angle, p=a+b, and p (the size of a pixel) is a constant. A good 3D effect can be seen only at a narrow, shadow region on a right side, here, the angle θ is an important parameter. A computation can be performed in accordance with the simplified principle view shown in FIG. 2, and the 3D viewing angle θ meets the following relation:
      tan    ⁢          θ      2        =                    2        ⁢                                  ⁢        p            +      b      -              2        ⁢                                  ⁢        c                    2      ⁢                          ⁢      h      
It can be seen from the above relation that θ increases with the increase of a width b of the BM. Accordingly, a scheme in which an active BM is used is proposed, and its structure is shown in FIG. 3. In the scheme shown in FIG. 3, one sub-pixel unit is divided into two small pixels in the upper and in the lower, namely a first sub-pixel 1 and a second sub-pixel 2, and they are controlled separately. When a 2D display is carried out, the same content is displayed by the first sub-pixel 1 and the second sub-pixel 2; and when a 3D display is carried out, the second sub-pixel 2 represents black, which is equivalent to increasing of the width b of the BM for an original pixel, so that the 3D viewing angle can be improved.
However, in a general active BM scheme, the second sub-pixel 2 is controlled as a separate pixel, and as a result, the number of gate lines of the display panel will become twice as much as the original case, and the number of data signal lines will become twice as much as the original case. Thus, the control cost and the control difficulty are increased.