Patent Grant
9311873
The present disclosure relates to a technical field of liquid crystal display, and particularly, to a polarity inversion driving method for a liquid crystal display panel, a driving apparatus and a display device.
Due to advantages of stable pictures, vivid images, eliminated radiation, economic space, economic power consumption and the like, Thin Film Transistor-Liquid Crystal Displays (TFT-LCDs) are widely applied to electronic products such as televisions, mobiles, displays and the like, and are dominant in the field of tablet display.
The liquid crystal display shown in
An elementary image display unit of the liquid crystal display panel is a sub-pixel which takes on a capacitance effect in liquid crystal display panel structure, and an image will be displayed as long as a sufficient driving voltage is applied to two terminals thereof; and voltages applied to the two terminals of the capacitor are a common voltage and a data line voltage respectively. Therefore, if positive and negative polarity inversion is not performed on the voltage applied to the two terminals of the capacitor, the sub-pixels displaying the image will be charged for a long time with the same direct current voltage, and then a certain amount of charges will be deposited for a long time in a liquid crystal orientation layer and a liquid crystal layer between the common electrode and the pixel electrode, as shown in
Even if the signal voltages with the positive and negative polarity are alternatively applied to the sub-pixels of the liquid crystal display panel, however, it is still possible that the signal voltages finally applied to the sub-pixels of the liquid crystal display panel are undesirable in terms of the positive and negative symmetry due to factors such as original positive and negative voltages provided by the driving circuit being undesirable in terms of symmetry, characteristics of the liquid crystal display panel itself being undesirable, an issue of image signal mode provided by a custom system, signal instability or the like; after the image is display for a long time, due to deflection to a certain polarity as a whole, the issues of the liquid crystal polarization or image sticking will occur generally.
The present disclosure provides a polarity inversion driving method for a liquid crystal display panel to avoid such a issue that liquid crystal polarization or image sticking occurs in the liquid crystal at time of polarity inversion driving; further, embodiments of the present disclosure also provide a polarity inversion driving apparatus for the liquid crystal display panel for implementing the driving method, and a display device comprising the polarity inversion driving apparatus for the liquid crystal display panel.
Technical solutions according to embodiments of the present disclosure are as follows.
A polarity inversion driving method for a liquid crystal display panel comprises: each of frames being divided into M polarity arrangement units in a same way, every 2×M×N frames being one inversion driving period, in each of half inversion driving periods, ∃!xε(0, M×N], between the x-th frame and the (x+1)-th frame, except that polarities of first polarity arrangement units are same, polarities of all polarity arrangement units are opposite; ∀mε[0, M), between in the (x+m×N)-th frame and the (x+m×N+1)-th frame, except that polarities of (m+1)-th polarity arrangement units are same, polarities of all polarity arrangement units are opposite; the polarity of each of the other frames is opposite to that of a frame adjacent thereto; wherein, each of M, N, x and m is an integer number, and value of M×N is an even number; when one of expressions of (x+1)>M×N, (x+m×N)>M×N or (x+m×N+1)>M×N is satisfied, (x+1) represents the first frame in the half inversion driving period, (x+m×N) represents the (x+m×N−M×N)-th frame in the half inversion driving period, and (x+m×N+1) represents the (x+m×N−M×N+1)-th frame in the half inversion driving period, wherein in two of the half inversion driving periods adjacent to each other, the polarities of corresponding frames are opposite.
Optionally, in the x-th frame of each of the half inversion driving period, polarities of any two adjacent polarity arrangement units are opposite.
Optionally, each of the frames represents a polarity arrangement unit, N being an even number, polarity inversion driving period is a frame of 2N, and in each of the half inversion driving periods, only one set of two frames adjacent to each other are same in terms of polarity, and the other sets of two frames adjacent to each other are opposite in terms of polarity.
Optionally, in each of the frames, P rows are configured as a polarity arrangement unit.
Optionally, in each of the frames, each of the rows is a polarity arrangement unit; the first polarity arrangement unit is the first row, and the (m+1)-th polarity arrangement unit is the (m+1)-th row.
Optionally, M is an even number and N is equal to 1.
Optionally, in each of the polarity arrangement units, polarities of any two adjacent sub-pixels are opposite.
Optionally, the polarity is a polarity with respect to a common electrode voltage.
An embodiment of the present disclosure also provides an apparatus for implementing any one of the above polarity inversion driving method for the liquid crystal display panel.
The apparatus for the polarity inversion driving method for the liquid crystal display panel, comprises a timing controller, a source driver and an calculator, wherein the timing controller outputs M polarity inversion signals corresponding to each of the polarity arrangement units respectively to the calculator, and the polarity inversion signals and the control signal are subjected to logic operation in the calculator to be inputted to the source driver;
in each of half inversion driving periods, the polarity inversion signal in the (x+m×N+1)-th frame corresponding to the (m+1)-th polarity arrangement unit is an in-phase signal of a corresponding polarity inversion signal in the (x+m×N)-th frame, and the polarity inversion signal in the other frames corresponding to the (m+1)-th polarity arrangement unit is an out-phase signal of a corresponding polarity inversion signal in a previous frame.
Optionally, the second polarity inversion signal corresponding to the (m+1)-th polarity arrangement unit is POLm+1, the control signal Csm+1 corresponding to the second polarity inversion signal is a high level in the (x+m×N)-th frame, and is at a low level in other frames; the second polarity inversion signal in each of the frames corresponding to the (m+1)-th polarity arrangement unit and the control signal are subjected to a logic operation of
Optionally, the second polarity inversion signal corresponding to the (m+1)-th polarity arrangement unit is POLm+1, the control signal Csm+1 corresponding to the second polarity inversion signal is a low level in the (x+m×N)-th frame, and is at a high level in other frames; the second polarity inversion signal in each of the frames corresponding to the (m+1)-th polarity arrangement unit and the control signal are subjected to a logic operation of
An embodiment of the present disclosure also provides a display device comprising the above polarity inversion driving apparatus for the liquid crystal display panel.
With polarity inversion driving method for a liquid crystal display panel according to the embodiments of the present disclosure, in each of the polarity inversion driving periods, the overall polarities of the sub-pixels will not be deflected to a certain polarity, the charges are prevented from being accumulated, and such a issue that liquid crystal polarization or image sticking occurs in the liquid crystal at time of polarity inversion driving is avoided.
Hereinafter, specific implementations of the present disclosure will be further described with reference to the appended drawings and embodiments. The following embodiments are only intended to illustrate the present disclosure, and are not to limit the scope of the present invention.
In a polarity inversion driving method for a liquid crystal display panel according to an embodiment of the present disclosure, each of frames is divided into a number of M of polarity arrangement units in a same way; it is possible that every P rows form a polarity arrangement unit, the example of which is that every row forms a polarity arrangement unit or every two rows form a polarity arrangement unit or the like, and it is also possible that a frame forms a polarity arrangement unit; every 2×M×N frames indicate an inversion driving period, in each of half inversion driving periods M×N: ∃!xε(0, M×N], between the x-th frame and the (x+1)-th frame, except for the polarity of the first polarity arrangement unit, polarities of all the polarity arrangement units are opposite; that is, between the x-th frame and the (x+1)-th frame, only the polarities of the first arrangement units are the same, and the polarities of the second to the M-th polarity arrangement units are opposite; between any other two adjacent frames during the half inversion driving period, the polarities of the first polarity arrangement units are opposite, where ∃! represents any number in a range;
∀mε[0, M), between the (x+m×N)-th frame and the (x+m×N+1)-th frame, except for the polarity of the (m+1)-th polarity arrangement unit, polarities of all the polarity arrangement units are opposite; that is, whatever the value of m is, between the (x+m×N)-th frame and the (x+m×N+1)-th frame, the polarities of the (m+1)-th polarity arrangement units are the same, and the polarities of the first to the m-th and the (m+2)-th to the M-th polarity arrangement units are opposite; in any other two adjacent frames during the half inversion driving period, the polarities of the (m+1)-th polarity arrangement units are opposite, where V represents that the numeral in the range can be applicable in sequence;
during the half inversion driving period, the polarity of each of the other frames is opposite to that of a frame adjacent thereto are opposite; wherein, each of M and N is an integer number, value of M×N is an even number, and N represents that the inversion driving of positive and negative polarity alternation in every two frames is performed once every N frames; each of x and m is an integer number; when (x+1)>M×N, (x+1) represents the first frame in the half inversion driving period; when (x+m×N)>M×N, (x+m×N) represents the (x+m×N−M×N)-th frame in the half inversion driving period; when (x+m×N+1)>M×N, (x+m×N+1) represents the (x+m×N−M×N+1)-th frame in the half inversion driving period;
in any two of the half inversion driving periods adjacent to each other, the polarities of corresponding frames are opposite.
In one of the inversion driving periods, the overall polarity of each of the polarity arrangement units will not be deflected to a certain polarity, and thus it is avoided that the liquid crystal polarization or image sticking occurs in the liquid crystal at time of polarity inversion driving.
Hereinafter, specific implementations of the embodiments of the present disclosure will be explained in conjunction with examples.
In this embodiment, a case where each of the frames is a polarity arrangement unit and N is an even number will be illustrated.
In the existing polarity inversion driving for the liquid crystal display panel, polarity inversion of a pixel voltage signal is performed once every frame; the known polarity inversion driving apparatus for the liquid crystal display panel is as shown in
As shown in tables 1 and 2, under control of the polarity inversion signal POL_1, polarities of any adjacent sub-pixels are opposite to each other and the polarities of any two frames adjacent to each other are opposite to each other; in this embodiment, the polarity is a polarity with respect to the voltage of a common electrode; in the tables 1 and 2, a symbol of “+” indicates a positive voltage with respect to the voltage of the common electrode, and the symbol of “−” indicates a negative voltage with respect to the voltage of the common electrode.
Due to factors such as original positive and negative voltages provided by the driving circuit being undesirable in terms of symmetry, characteristics of the liquid crystal display panel itself being undesirable, a issue of image signal mode provided by a custom system, signal instability or the like, it is possible that the signal voltages finally applied to the sub-pixels of the liquid crystal display panel are undesirable in terms of the positive and negative symmetry; for example, as shown in table 3, the overall polarity thereof is negative. In this way, after an image is displayed for a long time, the pixel voltage signal of each of sub-pixels is deflected to a certain polarity as a whole. For a single sub-pixel shown in
On the basis of the driving method in which the positive and negative polarities are alternatively inverted per frame as described above, in the polarity inversion driving method for the liquid crystal display panel according to the embodiments of the present disclosure, every N frames, the inversion driving of positive and negative polarities alternation in two frames is performed once (referred to as two-frame inversion hereinafter), as shown in
As can be apparently seen from
As shown in
In order to reduce impact of interference phenomenon of chroma and brightness in a frame, in the present embodiment, polarities of any two adjacent sub-pixels in each of the frames are opposite. Of course, other implementations are also possible; for example, three sub-pixels of RGB serve as a pixel unit, and polarities of any two adjacent pixel units in each of the frames are opposite, and the like.
The polarity inversion driving method for the liquid crystal display panel of the first embodiment is easy to be implemented and operated, however, since when the two-frame inversion is performed every N frames, the change in polarity of the full picture is not consistent with that of the other frames, and thus light and dark changes are generated, which is visually presented as a flicker phenomenon. In order to solve this issue, in this embodiment, each of the rows is a polarity arrangement unit; every N frames, the two-frame inversion is performed once on this row, and the two-frame inversion is performed alternatively on the respective rows, so that it is avoided that the full picture is changed simultaneously. For example,
In the present embodiment, in the x-th frame (first frame) as the start frame of each of half inversion driving periods, polarities of any two rows adjacent to each other are opposite, and polarities of two adjacent sub-pixels on each of the rows are opposite; all of these are to reduce the impact of interference phenomenon of chroma and brightness in a frame. Of course, for practical application, it is also possible to adjust the polarity arrangement of the respective polarity arrangement units and adjust the division of the respective polarity arrangement units as necessary, and is not limited to the polarity arrangement and division form of the polarity arrangement units exemplified in the present embodiment.
Embodiments of the present disclosure also provide a driving apparatus for implementing any one of the above polarity inversion driving methods for the liquid crystal display panel; as shown in
An embodiment of the present disclosure further provides a display device comprising the above polarity inversion driving apparatus for the liquid crystal display panel; since the adopted polarity inversion driving apparatus addresses such a issue that liquid crystal polarization or image sticking occurs in the liquid crystal at time of polarity inversion driving, this display device enjoys a relatively high reliability, and can optimize and improve user's experience to some extent. The display device can be any of products or means with display function, such as liquid crystal display panel, electronic paper, liquid crystal TV, liquid crystal display, organic electroluminescence display, digital photo frame, mobile, tablet computer or the like.
The above embodiments are only intended to explain the present disclosure, and are not a limitation to the present disclosure; those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure; therefore, all of the equivalent technical solutions should also fall into the protection scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013 1 0282845 | Jul 2013 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2013/084658 | 9/30/2013 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2015/000234 | 1/8/2015 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20150084941 A1 | Mar 2015 | US |
