CN115331640B - Liquid crystal polarity inversion driving method and device and liquid crystal display equipment - Google Patents

Abstract

The invention discloses a liquid crystal polarity reversal driving method, which is applied to a liquid crystal display panel; wherein the method includes: obtaining the cycle period of a target display object and the refresh rate of the liquid crystal display panel; the target display object includes K sub-objects, and the cycle The cycle is the duration for sequentially outputting K sub-objects to the display panel, and K is a positive integer; based on the cycle period and refresh rate, determine the number of period frames corresponding to the cycle period; based on the number of period frames, generate a polarity reversal signal for each cycle period ;The polarity reversal signals of two adjacent cycles are inverted, and the polarity reversal signals are used to control the liquid crystal polarity of the liquid crystal display panel. The present invention can effectively suppress the flicker failure of the screen when the liquid crystal display panel displays a high-frequency cyclic screen.

Description

A liquid crystal polarity reversal driving method, device and liquid crystal display equipment

Technical field

The present invention relates to the field of display technology, and in particular, to a liquid crystal polarity reversal driving method, device and liquid crystal display equipment.

Background technique

BD CELL technology refers to a solution that uses two upper and lower OC (Open Cell, LCD panels) laminated together through related technologies. The main panel (Main Cell) is on the upper layer and mainly focuses on color control to form a visual color impact. The panel (Sub Cell) is on the lower layer and is a black and white screen. It is mainly used for fine dimming to present high contrast and rich dark details. BDCELL products, due to Sub Cell's fine dimming and Local Dimming (local dimming) design, the contrast ratio can reach millions of levels and can be used as a broadcast-level display. Therefore, some high-frequency looping images are often output to the display; since high brightness will adversely affect the characteristics of liquid crystal and TFT (Thin Film Transistor, thin film transistor), poor screen flickering will occur after receiving and playing such images for a long time. For example, when playing time code for timing, serious flicker failure will occur at the corresponding position of the display after a long period of playback.

Therefore, current display products will suffer from flickering after receiving high-frequency looping images and playing them for a long time.

Contents of the invention

In view of the above problems, the present invention proposes a liquid crystal polarity inversion driving method, device and liquid crystal display device, which can effectively suppress the flicker failure of the picture when the liquid crystal display panel displays high-frequency cyclic pictures.

In the first aspect, this application provides the following technical solution through an embodiment:

A liquid crystal polarity reversal driving method, applied to a liquid crystal display panel, the method includes:

Obtain the cycle period of the target display object and the refresh rate of the liquid crystal display panel; the target display object includes K sub-objects, the cycle period is the duration of sequentially outputting the K sub-objects to the display panel, and K is positive Integer; based on the cycle period and the refresh rate, determine the number of period frames corresponding to the cycle period; based on the number of period frames, generate a polarity reversal signal for each cycle period; two adjacent ones The polarity reversal signal is inverted in the cycle period, and the polarity reversal signal is used to control the liquid crystal polarity of the liquid crystal display panel.

Optionally, the polarity reversal signal includes a first reversal signal and a second reversal signal; and generating a polarity reversal signal for each cycle period based on the cycle frame number includes:

Based on the periodic frame number, a first inversion signal and a second inversion signal for each of the cycle periods are generated; wherein, for each of the cycle periods, between the first inversion signal and the second inversion signal Between the inverted signals, the level of the M-1th frame is the same, the level of the Mth frame is inverted, the level of the first frame is the same, and M is the number of frames in the period.

Optionally, the polarity reversal signal further includes: a data reversal signal; and generating a polarity reversal signal for each cycle period based on the cycle frame number includes:

Based on the period frame number, a first inversion signal, a second inversion signal and a data inversion signal for each of the cycle periods are generated; wherein, for each of the cycle periods, in the first inversion signal Between the data inversion signal and the data inversion signal, the levels of the first frame, the M-1th frame and the Mth frame are all inverted.

Optionally, if the number of periodic frames is an even number, after determining the number of periodic frames corresponding to the cyclic period, the method further includes: controlling the scanning start signal and scanning corresponding to the first frame of each cyclic period. The clock signal output is low level.

Optionally, applied to the scenario: the total time for the liquid crystal display panel to refresh K frames is longer than the cycle period.

Optionally, the target display object is a 10ms character in the time display.

Optionally, the method further includes: controlling the refresh rate of the liquid crystal display panel to be no less than 100Hz.

Optionally, the method further includes: controlling the refresh rate of the liquid crystal display panel to 200Hz.

In the second aspect, based on the same inventive concept, this application provides the following technical solution through an embodiment:

A liquid crystal polarity reversal driving device, applied to a liquid crystal display panel, the liquid crystal polarity reversal driving device includes:

The periodic frame number determination module is used to obtain the cycle period of the target display object and the refresh rate of the liquid crystal display panel; the target display object includes K sub-objects, and the cycle period is to sequentially output the K sub-objects to the display panel. The duration of the sub-object, K is a positive integer; the polarity reversal signal generation module is used to determine the number of periodic frames corresponding to the cycle period based on the cycle period and the refresh rate; the polarity reversal signal generation module, Used to generate a polarity reversal signal for each cycle based on the cycle frame number; the polarity reversal signals of two adjacent cycles are inverted, and the polarity reversal signal is For controlling the liquid crystal polarity of the liquid crystal display panel.

In the third aspect, based on the same inventive concept, this application provides the following technical solution through an embodiment:

A liquid crystal display device includes the liquid crystal polarity reversal driving device described in the second aspect.

The present invention provides a liquid crystal polarity reversal driving method and device by obtaining the cycle period of the target display object output to the liquid crystal display panel and the refresh rate of the display panel. Thus, the number of frames corresponding to each cycle can be obtained, that is, the number of cycle frames; that is, how many frames of images can be refreshed in one cycle. Therefore, when generating the first polarity inversion signal of each cycle period, the first polarity inversion signal of two adjacent periods is controlled to be opposite, so that two frames of the same sub-object can be refreshed every two adjacent periods. The polarity of the liquid crystal in the picture is opposite, which effectively suppresses the polarization phenomenon of the liquid crystal and improves the flickering problem of high-frequency cycle pictures.

The above description is only an overview of the technical solution of the present invention. In order to have a clearer understanding of the technical means of the present invention, it can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present invention more obvious and understandable. , the specific embodiments of the present invention are listed below.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts. In the attached picture:

Figure 1 shows a waveform diagram of a polarity reversal signal in an embodiment of the present invention;

Figure 2 shows a schematic diagram of liquid crystal polarity change under the control of the polarity reversal signal of Figure 1;

Figure 3 shows a schematic diagram of the 10ms bits of the time code in the embodiment of the present invention;

Figure 4 shows a waveform diagram of the source driving signal under the control of the polarity inversion signal of Figure 1;

FIG5 is a schematic diagram showing the overlapping positions of the numbers 0 and 1 displayed by the liquid crystal display panel in an embodiment of the present invention;

Figure 6 shows a flow chart of a liquid crystal polarity reversal driving method in an embodiment of the present invention;

Figure 7 shows a schematic diagram of level maintenance of the first inversion signal appearing in two adjacent frames in the embodiment of the present invention;

Figure 8 shows a schematic diagram of the principle of not outputting the first frame of the cycle under the control of the first inversion signal in the embodiment of the present invention;

Figure 9 shows a schematic diagram of liquid crystal polarity changes under the control of the first inversion signal and the second inversion signal in the embodiment of the present invention;

Figure 10 shows a schematic diagram of the principle of not outputting the first frame of the cycle under the control of the first inversion signal and the second polarity inversion signal in the embodiment of the present invention;

Figure 11 shows a schematic diagram of liquid crystal polarity changes under the control of the first inversion signal, the second inversion signal and the data inversion signal in the embodiment of the present invention;

Figure 12 shows a schematic diagram of the principle of not outputting the first frame of the cycle under the control of the first inversion signal, the second polarity inversion signal and the data inversion signal in the embodiment of the present invention;

Figure 13 shows a schematic structural diagram of a liquid crystal polarity reversal drive in an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a thorough understanding of the disclosure, and to fully convey the scope of the disclosure to those skilled in the art.

In some implementations, in order to avoid liquid crystal polarization, when switching between different frames, the level of the control polarity reversal signal changes once, as shown in Figure 1, so that the corresponding liquid crystal driving voltage polarity changes once as a whole, as shown in Figure 1. As shown in Figure 2. The liquid crystal driving voltage can be the source driving signal (SD) generated by the data line driving circuit. Although, in this way, liquid crystal polarization can be avoided to a certain extent and flickering defects of the display screen can be suppressed to a certain extent. However, after verification, it was found that when this method is used to output some high-frequency cyclically changing pictures to the display panel, flickering defects of the display picture will still occur.

For example, when using time code software for timing, when displayed on the display panel for a long time, poor flickering will occur at the 10ms position of the time code, as shown in Figure 3 at position A of number 3. In response to this, the inventor further analyzed and found that for a 60Hz display panel, the relationship between the numbers displayed at the 10ms position and the numbers displayed at each frame refresh is as shown in Table 1 below.

Table 1: Time code 10ms position display number

That is to say, in a 60Hz display panel, for the 10ms position of the time code: it is displayed as 0 in the first frame. When the time reaches 10ms, since the refresh time of one frame is 16.7ms, that is to say, after 10ms The number 1 should be displayed at 6.7ms, but because the display screen is not refreshed, it still displays 0. When refreshing to the second frame, it does not take more than 20ms (there is still 3.3ms to display the number 1), so the number 1 continues to be displayed; then after reaching 20ms, the number 2 should be displayed, but the display screen has not been refreshed to the third frame. frame, so the number 1 continues to be displayed. When the third frame is refreshed, it has reached 33.4ms, and the time for displaying the number 2 has ended for 3.4ms, so when the third frame is refreshed, the display screen displays the number 3. By analogy, when the seventh frame is reached, it will be displayed as 0; it can be determined that between 0 and 9, the display panel will only display cyclically: 0, 1, 3, 5, 6, 8; and a cycle period is 100ms , occupying 6 frames. That is, the display is repeated every 6 frames.

Furthermore, assuming that the polarity of the driving voltage at the position where the first frame displays 0 is positive, after one cycle, the first frame at the beginning of the next cycle will continue to display 0. At this time, after 6 frames of polarity change, the The LCD driving voltage at the position is still positive. As a result, when displaying 0, the liquid crystal is always forward biased. In the same way, when displaying other numbers, the LCD driving voltage is also the same, and the LCD is also biased to the same side. As shown in Figure 4, after verification of the source drive signal, it can also be seen that the source drive signal is exactly the same in two adjacent cycles; for example, signal B1 corresponds to the first frame of a cycle, and signal B2 Corresponding to the first frame of the next cycle, the two polarities are the same. Therefore, polarization will occur after long-term deflection on the same side, which will affect the performance of the liquid crystal.

In addition, the data differences between 0 and 1, 1 and 3, 3 and 5, 5 and 6, and 6 and 8 are relatively large. As shown in Figure 5, taking 0 and 1 as an example, only the positions marked 1, 2 and 3 in the figure have the same data, and the data at other positions are different. The points 0 and 1 belong to the two frames before and after, one belongs to the positive frame and the other belongs to the negative frame. When the number difference is large, the liquid crystal cannot achieve symmetrical deflection unless the positions other than 1, 2, and 3 are marked. , liquid crystal polarization will also occur after a long time, affecting liquid crystal performance.

Therefore, combined with the above two reasons, the liquid crystal deflection is often in an asymmetrical state at the 10ms position of the time code, and flickering failure will occur after long-term display.

In view of this, the present invention provides a liquid crystal polarity reversal driving method and device. By controlling the generated polarity reversal signal, when the target display object is output cyclically, such as outputting the number at the 10ms position of the time code, each phase The polarity reversal signals in two adjacent cycles are opposite, thereby ensuring that the polarity of the liquid crystal when the target display object is displayed in the corresponding two frames in each two adjacent cycles is opposite, thereby effectively suppressing the polarization phenomenon of the liquid crystal. Improve the flickering problem of high-frequency looping images. The overall concept of the present invention will be elaborated and illustrated in more detail below by means of one or more embodiments.

Referring to FIG. 6 , in some embodiments of the present invention, a liquid crystal polarity reversal driving method is provided, which can be applied to a liquid crystal display panel and used to generate a polarity reversal signal that controls the polarity of a liquid crystal driving voltage. The liquid crystal polarity reversal driving method includes:

Step S10: Obtain the cycle period of the target display object and the refresh rate of the liquid crystal display panel; the target display object includes K sub-objects, and the cycle period is the duration for sequentially outputting the K sub-objects to the display panel, K is a positive integer;

Step S20: Based on the cycle period and the refresh rate, determine the number of periodic frames corresponding to the cycle period;

Step S30: Based on the periodic frame number, generate a polarity reversal signal for each cycle; the polarity reversal signals of two adjacent cycles are inverted, and the polarity reversal signal Used to control the liquid crystal polarity of the liquid crystal display panel.

In steps S10-S30 of this implementation, first, the cycle period of the target display object output to the liquid crystal display panel and the refresh rate of the display panel are obtained. Thus, the number of frames corresponding to each cycle can be obtained, that is, the number of cycle frames; that is, how many frames of images can be refreshed in one cycle. Therefore, when generating the first polarity inversion signal of each cycle period, the first polarity inversion signal of two adjacent periods is controlled to be opposite, so that two frames of the same sub-object can be refreshed every two adjacent periods. The polarity of the liquid crystal in the picture is opposite, which effectively suppresses the polarization phenomenon of the liquid crystal and improves the flickering problem of high-frequency cycle pictures. The specific time limit of each step in this embodiment will be described in detail below.

Step S10: Obtain the cycle period of the target display object and the refresh rate of the liquid crystal display panel; the target display object includes K sub-objects, and the cycle period is the duration for sequentially outputting the K sub-objects to the display panel, K is a positive integer.

In step S10, the K sub-objects included in the target display object are contents output to the liquid crystal display panel. And the cyclic display is performed according to a certain cycle period. However, due to the limitation of the refresh rate of the LCD panel, not every K sub-object output to the LCD panel will be displayed by the LCD panel. That is, not every sub-object can be assigned to a frame of image. In particular, if the total time it takes for the LCD panel to refresh K frames is longer than the cycle period, there is no guarantee that each sub-object can be assigned one frame of image. Furthermore, the liquid crystal display panel may only display some sub-objects in a cycle.

Taking a 60Hz LCD monitor and the 10ms bit of the time code as an example, the target display object is the content displayed in the 10ms bit. At this time, K = 10; the K sub-objects are 0, 1, 2, 3, 4, 5, 6, respectively. 7, 8, 9. The 10ms bit displays 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 in sequence for 100ms, and the cycle period is 100ms. At this time, the LCD panel will only display 0, 1, 3, 5, 6, 8 in a cycle. The reasons have been analyzed previously and will not be repeated again.

It should be noted that the target display object may also be specific content set by the user for display, such as specific images, specific numbers, specific letters, etc. that are displayed in a loop. Taking the target display object as a specific letter as an example, the sub-objects can be A, B, C, D, E, F; the cycle period can also be set, for example, it can be 90ms, 100ms, 120ms, etc. Taking the target display object as a specific image as an example, the sub-objects can be image 1, image 2, image 3, image 4, image 5, image 6, image 7; the cycle period can be set to 90ms, 100ms, 120ms, etc. In other words, there is no restriction on the expression form of the target display object.

Further, the application scenario in this embodiment may be: the sub-objects output to the liquid crystal display panel have the same time interval. In this scenario, a better effect of suppressing flicker failure can be achieved. For example, the 10ms bit of the time code outputs a number every 10ms.

Step S20: Based on the cycle period and the refresh rate, determine the number of periodic frames corresponding to the cycle period.

In step S20, the time it takes to refresh one frame can be obtained based on the refresh rate, which is recorded as the duration of a single frame. Divide the cycle period by the duration of a single frame to obtain the number of periodic frames in the cycle; that is, the number of refresh frames of the liquid crystal display panel in one cycle. For example, in a 60Hz LCD panel, when the target display object is a time code of 10ms, the number of periodic frames is 6 frames; in a 100Hz LCD panel, when the target display object is a time code of 10ms, the number of periodic frames is 10 frames .

Step S30: Based on the periodic frame number, generate a polarity reversal signal for each cycle; the polarity reversal signals of two adjacent cycles are inverted, and the polarity reversal signal Used to control the liquid crystal polarity of the liquid crystal display panel.

In step S30, since the number of periodic frames is determined, when generating the polarity reversal signal of each cycle period, the polarity reversal signals of two adjacent cycle periods can be controlled to be inverted. Therefore, when the same sub-object is displayed in two adjacent cycles, the polarity of the liquid crystal driving voltage is opposite, that is, the liquid crystal deflects symmetrically when the sub-object is displayed twice before and after, effectively suppressing the problem of the target display object after playing for a long time. The flickering that occurs is bad. The polarity reversal signal can be output to the polarity reversal signal through the signal line to control whether the liquid crystal driving voltage output by the polarity reversal signal is reversed, thereby achieving control of the liquid crystal polarity. For more specific implementation methods, please refer to existing implementation solutions, which will not be described again here. Further, the generated polarity reversal signal has the following multiple implementation methods:

1. The generated polarity reversal signal includes the first reversal signal (POL).

In some examples, if the polarity of the liquid crystal driving voltage of each two adjacent frames is opposite, then when the number of cycle frames is an odd number, and after the polarity reversal signal of the two adjacent cycles is inverted, In an inverted signal, there will be no two adjacent frames with the same level. The levels of every two adjacent frames are inverted, and the levels of every two adjacent cycles are overall inverted.

For example, 0 represents the low level in the first inversion signal, and 1 represents the high level in the first inversion signal; if the number of periodic frames is 5, then the first inversion signal of two cycles is expressed as: 01010 10101. Therefore, it can be ensured that the polarity of the liquid crystal driving voltage in adjacent cycles is opposite, and the polarity of the liquid crystal driving voltage in any two consecutive frames is also opposite, which can make the liquid crystal deflection direction more symmetrical and effectively suppress flicker failure.

In other examples, if the polarity of the liquid crystal driving voltage of each two adjacent frames is opposite, then when the number of periodic frames is an even number of frames, after the polarity reversal signal of the two adjacent cycles is controlled to be inverted, it can also be The polarity of the liquid crystal driving voltage in adjacent cycles is reversed to suppress flicker failure. However, in this case, the levels of adjacent frames will be the same at the junction of the preceding and following periods; in this case, the picture may also flicker slightly when the polarity of the liquid crystal is reversed in the next frame of the two frames. For example, 0 represents the low level in the first inversion signal, and 1 represents the high level in the first inversion signal; if the number of periodic frames is 6, then the first inversion signal of two cycles is expressed as: 010101101010; In this example, the two adjacent frames at the cycle boundary are both high level. As shown in Figure 7, the number of periodic frames M is an even number. The Mth frame of one cycle _Tn and the first frame (M+1th frame) of the next cycle Tn ₊₁ will have the same level. , both are high level.

To this end, in some embodiments, after step S20, the scan start signal (STV) and scan clock signal (CLK) corresponding to the first frame of each cycle period can be controlled to be output to a low level, so that during the cycle period The first frame is not output, as shown in Figure 8. It can be understood that it can be implemented in a counting manner by modifying the register code of TCON (TimingController, timing controller); when the first inversion signal is maintained, the held frame is not output. This avoids the flicker failure caused by reversing the polarity of the liquid crystal driving voltage after maintaining it.

2. The generated polarity inversion signal includes a first inversion signal (POL) and a second inversion signal (POL2).

In this implementation, a second inversion signal is added compared to the first implementation, that is, step S30 is specifically: based on the number of periodic frames, generate the first inversion signal and the second inversion signal for each cycle. Reversal signal. The second inversion signal cooperates with the first inversion signal to control the polarity of the liquid crystal. It can be understood that the inversion of polarity reversal signals in two adjacent cycles means: the first inversion signal in one cycle is inverted with the first inversion signal in the next cycle; The second inversion signal is inverted with the second inversion signal of the next cycle period. Further, for each cycle period, between the first inversion signal and the second inversion signal, the level of the M-1th frame is the same, the level of the M-th frame is inverted, and the level of the first frame The same, M is the number of periodic frames, and the levels of other frames remain the same, as shown in Table 2.

Table 2: POL&POL2 truth table

Signal Frame M-1 Mth frame Frame M+1 POL L H H POL2 L L H

When the number of periodic frames is an even number, through the above signal combination, the liquid crystal polarity in the M-th frame can be partially reversed relative to the liquid crystal polarity in the M-1th frame, that is, H2DOT is turned on in the M-1th frame (one row Among the pixels, the polarity of each two pixels is reversed and separated by two pixels), and the polarity of the liquid crystal is completely reversed in the M+1th frame (the first frame of the next cycle). For example, the polarity of four adjacent pixels in frame M-1 is: -+-+-+-+; then the polarity of the four adjacent pixels in frame M is: +--++- -+; the polarities of the four adjacent pixels in the M+1th frame are: +-+-+-+-, as shown in Figure 9. This implementation method can also invert the polarity reversal signals of two adjacent cycles, and avoids that the liquid crystal polarity of the last frame of the previous cycle and the first frame of the next cycle are exactly the same, which can be further improved. Suppress the occurrence of flicker.

When the target display object is displayed on a more complex background screen, different pixel polarities need to be changed to ensure polarity balance. However, the voltage difference that needs to be changed during the polarity change of different pixels is quite different, and it is easy to occur. Polar symmetry is poor. In this regard, it is possible not to output the M+1th frame, that is, not to output the first frame of the cycle. As shown in Figure 10, the corresponding scan start signal (STV) and scan clock signal (CLK) are controlled to be output as Low level is sufficient. For specific implementation methods, please refer to the explanation in the first implementation method mentioned above, and will not be described again here.

3. The generated polarity inversion signal includes the first inversion signal (POL), the second inversion signal (POL2) and the data inversion signal (H4INV).

In this implementation mode, compared with the aforementioned second implementation mode, a data inversion signal is further added. That is, step S30 specifically includes: generating the first inversion signal, the second inversion signal and the data inversion signal of each cycle based on the period frame number. It can be understood that the inversion of polarity reversal signals in two adjacent cycles means: the first inversion signal in one cycle is inverted with the first inversion signal in the next cycle; The second inversion signal is inverted with the second inversion signal in the next cycle; the data inversion signal in one cycle is inverted with the data inversion signal in the next cycle. Further, for each cycle period, between the first inversion signal and the data inversion signal, the levels of the first frame, the M-1th frame and the Mth frame are all inverted. The levels for other frames remain the same, as shown in Figure 3.

Table 3: POL&POL2&H4INV truth table

Signal Frame M-1 Mth frame Frame M+1 POL L H H POL2 L L H H4INV H L L

When the number of periodic frames is an even number, through the above signal combination, the liquid crystal polarity in the M-th frame can be partially reversed relative to the liquid crystal polarity in the M-1th frame, that is, H2DOT and H4INV are turned on in the M-1th frame. (Every time the polarity of two pixels in a row of pixels is reversed, four pixels are spaced). The polarity of the liquid crystal in the M+1th frame is completely reversed. For example, the polarity of four adjacent pixels in frame M-1 is: -+-+-+-+; then the polarity of the four adjacent pixels in frame M is: +--+-+ +-; the polarities of the four adjacent pixels in the M+1th frame are: +-+-+-+-, as shown in Figure 11. This implementation method can also invert the polarity reversal signals of two adjacent cycles, and avoids that the liquid crystal polarity of the last frame of the previous cycle and the first frame of the next cycle are exactly the same, which can be further improved. Suppress the occurrence of flicker.

It can be understood that in this implementation, the M+1th frame in the cycle can also be controlled not to be output, that is, the first frame of the cycle is not output, as shown in Figure 12, the corresponding scan start signal ( STV) and the scan clock signal (CLK) can be output to a low level. The specific implementation method can refer to the explanation in the first implementation method mentioned above, and will not be described again here. Compared with the second implementation method mentioned above, this implementation method can better balance the liquid crystal polarity by inverting the liquid crystal polarity, and can suppress the flicker of long-term playback when the target display object is played against a more complex screen background. bad.

In this embodiment, the refresh rate of the liquid crystal display panel can also be controlled. It is understandable that when the frequency of sub-object switching in the target display object is too fast, one sub-object does not exceed one frame of image in a cycle, thus causing asymmetry in the display data and poor flickering after long-term display, especially in cycles. When the number of frames is an even number. When the LCD panel is controlled to display at a higher refresh rate, the flicker failure will be improved to a certain extent.

For example, the 10ms digits of the time code jump faster, and the time of each jump is 10ms. If the refresh rate is 60Hz, a number will be displayed for no more than two frames, resulting in data asymmetry. When the refresh rate is increased to 100Hz, each frame refresh takes exactly 10ms, that is, each 10ms digit of the time code corresponds to exactly one frame. When the refresh rate exceeds 100Hz, one number will be displayed for more than two frames. If the refresh rate is increased to 120Hz, the numerical correspondence between the frame number and the 10ms digit of the time code is shown in Table 4 below.

Table 4 When the refresh rate is 120Hz, the digital correspondence between the number of frames, liquid crystal polarity and the 10ms bit of the time code

As can be seen from Table 4 above, within a cycle, the numbers 4 and 9 can be displayed in two adjacent frames. The corresponding liquid crystal polarities of these two frames are opposite, which improves the polarity symmetry of the liquid crystal during the entire cycle display process. , reducing flickering defects. Therefore, in some implementations, the refresh rate of the LCD panel output can also be controlled to be greater than 100Hz, which can cope with most high-frequency target display objects including time code 10ms bits.

Furthermore, when the control refresh rate is further increased from 100Hz, between 120 and 200Hz, the degree of time code flickering will be significantly reduced as the refresh rate increases. Therefore, the refresh rate of the LCD panel output can also be controlled to be 120-200Hz. When the refresh rate is increased to 200Hz, the numerical correspondence between the number of frames and the 10ms digit of the time code is as shown in Table 5 below.

Table 5 When the refresh rate is 200Hz, the digital correspondence between the number of frames, liquid crystal polarity and the 10ms bit of the time code

As can be seen from Table 5 above, each display number of the 10ms time code can be allocated to two frames for display. The polarities of the liquid crystal corresponding to the two frames are opposite, so that the symmetrical state of the liquid crystal polarity is optimal and the flicker failure is basically eliminated. Will not appear. Therefore, the refresh rate of the LCD panel can be controlled at 200Hz to achieve better flicker suppression effect, especially when displaying time code, which can effectively eliminate flicker defects that occur at the 10ms bit. It should be noted that the control of the refresh rate can be implemented by referring to the existing solution, and will not be described again in this implementation.

To sum up, the liquid crystal polarity inversion driving method provided in this implementation obtains the cycle period of the target display object output to the liquid crystal display panel and the refresh rate of the display panel. Thus, the number of frames corresponding to each cycle can be obtained, that is, the number of cycle frames; that is, how many frames of images can be refreshed in one cycle. Therefore, when generating the first polarity inversion signal of each cycle period, the first polarity inversion signal of two adjacent periods is controlled to be opposite, so that two frames of the same sub-object can be refreshed every two adjacent periods. The polarity of the liquid crystal in the picture is opposite, which effectively suppresses the polarization phenomenon of the liquid crystal and improves the flickering problem of high-frequency cycle pictures.

Please refer to Figure 13. Based on the inventive concept, in another embodiment of the present invention, a liquid crystal polarity reversal driving device 300 is also provided, which is applied to a liquid crystal display panel. The liquid crystal polarity reversal driving device 300 include:

The periodic frame number determination module 301 is used to obtain the cycle period of the target display object and the refresh rate of the liquid crystal display panel; the target display object includes K sub-objects, and the cycle period is to sequentially output the The duration of K sub-objects, K is a positive integer; the polarity reversal signal generation module 302 is used to determine the number of periodic frames corresponding to the loop period based on the loop period and the refresh rate; the number of periodic frames is Even-numbered frames; the polarity reversal signal generation module 303 is configured to generate a polarity reversal signal for each cycle based on the cycle frame number; the polarity reversal of two adjacent cycles The signal is inverted, and the polarity inversion signal is used to control the liquid crystal polarity of the liquid crystal display panel.

As an optional implementation, the polarity reversal signal includes a first reversal signal and a second reversal signal; the polarity reversal signal generating module 303 is specifically used to:

Based on the periodic frame number, a first inversion signal and a second inversion signal for each of the cycle periods are generated; wherein, for each of the cycle periods, between the first inversion signal and the second inversion signal Between the inverted signals, the level of the M-1th frame is the same, the level of the Mth frame is inverted, the level of the first frame is the same, and M is the number of frames in the period.

As an optional implementation, the polarity reversal signal also includes: a data reversal signal; the polarity reversal signal generation module 303 is specifically used to:

Based on the period frame number, a first inversion signal, a second inversion signal and a data inversion signal for each of the cycle periods are generated; wherein, for each of the cycle periods, in the first inversion signal Between the data inversion signal and the data inversion signal, the levels of the first frame, the M-1th frame and the Mth frame are all inverted.

As an optional implementation, a scanning signal control module is also included. If the number of periodic frames is an even number, the scanning signal control module is configured to, after determining the number of periodic frames corresponding to the period:

The scan start signal and scan clock signal corresponding to the first frame of each cycle are controlled to be output to a low level.

As an optional implementation, applied to the scenario: the total time for the liquid crystal display panel to refresh K frames is longer than the cycle period.

As an optional implementation manner, the target display object is a 10ms character in the time display.

As an optional implementation manner, it also includes: a refresh rate control module, configured to control the refresh rate of the liquid crystal display panel to not be less than 100 Hz.

As an optional implementation, it also includes: a refresh rate control module, configured to control the refresh rate of the liquid crystal display panel to 200 Hz.

It should be noted that in the liquid crystal polarity reversal driving device 300 provided by the embodiment of the present invention, the functions implemented by each module and the beneficial effects produced are the same as those in the aforementioned method embodiments. For the sake of brief description, this implementation For matters not mentioned in the examples, please refer to the corresponding contents in the foregoing method embodiments.

Based on the same inventive concept, another embodiment of the present invention also provides a liquid crystal display device, which includes the liquid crystal polarity reversal driving device described in the previous embodiment. The liquid crystal display device may be a liquid crystal display panel, or may be other devices using liquid crystal display panels, such as large display screens, advertising screens, monitors, televisions, etc. In some implementations, each module of the polarity reversal driving device can be a code module that implements the function, which can be implemented by a processing chip; it can also be a circuit module that implements the corresponding function, without limitation. The generated polarity reversal signal can be output to the data line driving circuit, and the data line driving circuit outputs a corresponding liquid crystal driving voltage under the control of the polarity reversal signal, thereby controlling the liquid crystal polarity of the liquid crystal display panel.

It should be noted that the liquid crystal display device provided by the embodiment of the present invention applies the liquid crystal polarity reversal driving device in the previous embodiment. Therefore, the specific implementation and beneficial effects of the liquid crystal display device are the same as those in the previous embodiment. The methods and devices are the same. For the sake of brief description, for matters not mentioned in this embodiment, please refer to the corresponding content in the foregoing method or device embodiments.

The term "and/or" that appears in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the objects associated before and after are in an "or" relationship; the word "comprising" does not exclude the existence of elements or steps that are not listed in the claims. The word "one" or "an" placed before an element does not exclude the existence of multiple such elements. The present invention can be implemented with the aid of hardware including several different elements and with the aid of appropriately programmed computers. In a unit claim that lists several devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names.

Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce a use A device for realizing the functions specified in one process or multiple processes of the flowchart and/or one block or multiple blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory that causes a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction means, the instructions The device implements the functions specified in a process or processes of the flowchart and/or a block or blocks of the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device, causing a series of operating steps to be performed on the computer or other programmable device to produce computer-implemented processing, thereby executing on the computer or other programmable device. Instructions provide steps for implementing the functions specified in a process or processes of a flowchart diagram and/or a block or blocks of a block diagram.

Although the preferred embodiments of the present invention have been described, those skilled in the art will be able to make additional changes and modifications to these embodiments once the basic inventive concepts are apparent. Therefore, it is intended that the appended claims be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the invention. In this way, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims (10)

1. A method for driving a liquid crystal by polarity inversion, the method comprising:

acquiring a cycle period of a target display object and a refresh rate of the liquid crystal display panel; the target display object comprises K sub-objects, the cycle period is the duration of sequentially outputting the K sub-objects to the display panel, and K is a positive integer;

determining a cycle frame number corresponding to the cycle period based on the cycle period and the refresh rate;

generating a polarity inversion signal for each of the cycle periods based on the cycle frame number; the polarity inversion signals of two adjacent cycle periods are inverted, and the polarity inversion signals are used for controlling the polarity of liquid crystal of the liquid crystal display panel.

2. The method of claim 1, wherein the polarity inversion signal comprises a first inversion signal and a second inversion signal; the generating a polarity inversion signal for each of the cycle periods based on the cycle frame number includes:

generating a first inversion signal and a second inversion signal for each of the cycle periods based on the cycle frame number;

wherein for each cycle period, the level of the M-1 th frame is the same between the first inversion signal and the second inversion signal, the level of the M-1 th frame is inverted, the level of the first frame is the same, and M is the number of cycle frames.

3. The method of claim 2, wherein the polarity inversion signal further comprises: a data inversion signal; the generating a polarity inversion signal for each of the cycle periods based on the cycle frame number includes:

generating a first inversion signal, a second inversion signal, and a data inversion signal for each of the cycle periods based on the cycle frame number;

wherein the levels of the first frame, the M-1 th frame, and the M-th frame are inverted between the first inversion signal and the data inversion signal for each of the cycle periods.

4. A method according to any one of claims 1-3, wherein, if the cycle frame number is an even frame, after determining the cycle frame number corresponding to the cycle period, further comprising:

and controlling the scanning start signal and the scanning clock signal corresponding to the first frame of each cycle period to be output to be low level.

5. The method of claim 1, applied to a scene: the total time of refreshing the K frames of the liquid crystal display panel is longer than the cycle period.

6. The method of claim 1, wherein the target display object is a 10ms bit character in a time display.

7. The method according to claim 1 or 6, further comprising:

and controlling the refresh rate of the liquid crystal display panel to be not less than 100Hz.

8. The method according to claim 1 or 6, further comprising:

and controlling the refresh rate of the liquid crystal display panel to be 200Hz.

9. A liquid crystal polarity inversion driving device, which is applied to a liquid crystal display panel, comprising:

the cycle frame number determining module is used for acquiring the cycle period of the target display object and the refresh rate of the liquid crystal display panel; the target display object comprises K sub-objects, the cycle period is the duration of sequentially outputting the K sub-objects to the display panel, and K is a positive integer;

the polarity inversion signal generation module is used for determining a cycle frame number corresponding to the cycle period based on the cycle period and the refresh rate;

a polarity inversion signal generation module for generating a polarity inversion signal for each of the cycle periods based on the cycle frame number; the polarity inversion signals of two adjacent cycle periods are inverted, and the polarity inversion signals are used for controlling the polarity of liquid crystal of the liquid crystal display panel.

10. A liquid crystal display device comprising the liquid crystal polarity inversion driving apparatus as claimed in claim 9.