Debugging method for eliminating gray scale residual image

Abstract

This invention belongs to the field of liquid crystal display image quality adjustment technology, specifically a method for eliminating grayscale ghosting. The specific steps are as follows: Step S1, determine the gamma voltage of each grayscale level based on the grayscale voltage of the highest brightness level; Step S2, optimize and eliminate lateral crosstalk of the image, determine the grayscale voltage of the current brightness level, and use this grayscale voltage as the center voltage; Step S3, determine the grayscale brightness level where the ghosting is located, and change the voltage of the grayscale at the brightness level where the ghosting is located to reduce the positive and negative frame voltage difference between the grayscale at the brightness level where the ghosting is located and the grayscale at the highest brightness level; Step S4, evaluate the color quantity and lateral crosstalk performance. If the ghosting problem still exists, reset the voltage of the grayscale at the brightness level where the ghosting is located until the ghosting is eliminated; Step S5, complete the adjustment and output the software for saving. This method solves the voltage bias problem and eliminates image ghosting by adding binding points for adjustment.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal display image quality adjustment technology, specifically to an adjustment method for eliminating grayscale ghosting. Background Technology

[0002] As times progress and technology is constantly being updated, it is inevitable that old technologies will be replaced. In today's display industry environment, maintaining existing technologies faces obsolescence. In order to meet customer needs and update technologies to improve product competitiveness, this is the main direction for long-term stable development.

[0003] In the current LCD industry, product requirements are constantly increasing, and product testing is becoming more and more stringent. Rtings, a North American organization, mainly focuses on television evaluation. One of its tests is the Rtings IR test. With the backlight brightness ensuring a Panel L38 grayscale brightness of 2 nits, a test video is displayed for 10 minutes. After 10 minutes, the input signal is turned off, leaving obvious image retention. Analysis shows that due to a non-optimal code, under the influence of a DC electric field, ion accumulates on the PI film surface as rDC. Process variations lead to increased ion, and asymmetrical voltage bias causes the image retention to not be eliminated. This situation ultimately affects the customer experience, reduces product acceptance in the industry, and causes huge losses.

[0004] Therefore, a debugging method is needed to eliminate grayscale ghosting. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a debugging method for eliminating grayscale ghosting, thereby eliminating DC bias and reducing grayscale pressure difference.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A debugging method for eliminating grayscale ghosting, the specific steps of which are as follows:

[0008] Step S1: Determine the gamma voltage of each gray level using the gray level voltage of the highest brightness level;

[0009] Step S2: Optimize and eliminate lateral crosstalk of the image and determine the grayscale voltage of the current brightness level, using the grayscale voltage of the current brightness level as the center voltage.

[0010] Step S3: Determine the grayscale brightness level where the afterimage is located, and change the voltage of the grayscale at the brightness level where the afterimage is located to reduce the difference between the positive and negative frame voltage difference between the grayscale at the brightness level where the afterimage is located and the grayscale at the highest brightness level.

[0011] Step S4: Evaluate the color quantity and lateral crosstalk performance. If there is still a problem with image retention, reset the voltage of the grayscale of the brightness level where the image retention is located until the image retention is eliminated.

[0012] Step S5: Complete the debugging and output the software for saving.

[0013] Optionally, in one embodiment of the present invention, the following steps are further included before step S1:

[0014] Step S1 needs to be performed when the voltage of each symmetrical gray level is the same.

[0015] Optionally, in one embodiment of the present invention, in step S2, the current brightness level grayscale voltage is the brightness level grayscale voltage when horizontal crosstalk occurs in the image.

[0016] Optionally, in one embodiment of the present invention, in step S3, reducing the difference between the positive and negative frame voltage difference between the gray level of the brightness level where the afterimage is located and the gray level of the highest brightness level is: the voltage difference between the gray level voltage of the brightness level where the afterimage is located and the intermediate voltage and the voltage difference between the intermediate voltage and the gray level voltage of the highest brightness level.

[0017] Optionally, in one embodiment of the present invention, the specific implementation of reducing the difference between positive and negative frame voltage difference between the gray level of the brightness level where the afterimage is located and the gray level of the highest brightness level in step S3 is as follows: add a binding voltage to the gray level of the brightness level where the afterimage is located, and adjust the voltage difference between the gray level voltage of the brightness level where the afterimage is located and the intermediate voltage and the voltage difference between the gray level voltage of the highest brightness level and the intermediate voltage by adjusting the binding voltage.

[0018] Optionally, in one embodiment of the present invention, step S2 specifically involves optimizing and eliminating lateral crosstalk in the image by adjusting the VCOM voltage so that the VCOM voltage is located at the center value of the gamma voltage range.

[0019] Optionally, in one embodiment of the present invention, in step S3, the brightness level grayscale of the afterimage is determined by a playback experiment.

[0020] Optionally, in one embodiment of the present invention, in step S3, when determining the brightness level grayscale of the afterimage, if the afterimage appears at more than one brightness level grayscale, the brightness level grayscale of the different afterimages is adjusted separately.

[0021] Optionally, in one embodiment of the present invention, the magnitude of the binding voltage is adjusted by the voltage difference between the intermediate voltage and the grayscale voltage of the highest brightness level.

[0022] Beneficial effects of the invention

[0023] The present invention provides a method for adjusting grayscale ghosting to solve the problem of image ghosting caused by differences in manufacturing processes and asymmetrical large voltage bias. By increasing the grayscale binding voltage to adjust the voltage difference, the voltage difference of grayscale is reduced, thus eliminating ghosting. This method is applicable to adjusting grayscale at different brightness levels. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0025] Figure 1 A schematic diagram of the method in Embodiment 1 of the present invention. Detailed Implementation

[0026] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structure, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0027] Example 1

[0028] To eliminate the image retention problem on LCD screens, this is addressed by reducing the grayscale voltage difference and eliminating the DC bias. Therefore, a debugging method for eliminating grayscale retention is designed, and the specific scheme is as follows:

[0029] like Figure 1 As shown, a debugging method for eliminating grayscale ghosting includes the following specific steps:

[0030] Step S1: Determine the gamma voltage of each gray level using the gray level voltage of the highest brightness level;

[0031] Step S2: Optimize and eliminate lateral crosstalk of the image and determine the grayscale voltage of the current brightness level, using the grayscale voltage of the current brightness level as the center voltage.

[0032] Step S3: Determine the grayscale brightness level where the afterimage is located, and change the voltage of the grayscale at the brightness level where the afterimage is located to reduce the difference between the positive and negative frame voltage difference between the grayscale at the brightness level where the afterimage is located and the grayscale at the highest brightness level.

[0033] Step S4: Evaluate the color quantity and lateral crosstalk performance. If there is still a problem with image retention, reset the voltage of the grayscale of the brightness level where the image retention is located until the image retention is eliminated.

[0034] Step S5: Complete the debugging and output the software for saving.

[0035] The following steps are included before step S1:

[0036] Step S1 needs to be performed when the voltage of each symmetrical gray level is the same.

[0037] In step S2, the current brightness level grayscale voltage is the brightness level grayscale voltage when horizontal crosstalk occurs in the image.

[0038] In step S3, the difference between the positive and negative frame voltage difference between the gray level of the brightness level where the afterimage is located and the gray level of the highest brightness level is reduced as follows: the voltage difference between the gray level voltage of the brightness level where the afterimage is located and the intermediate voltage, and the voltage difference between the intermediate voltage and the gray level voltage of the highest brightness level.

[0039] In step S3, the specific implementation of reducing the positive and negative frame voltage difference between the gray level of the brightness level where the afterimage is located and the gray level of the highest brightness level is as follows: add a binding voltage to the gray level of the brightness level where the afterimage is located, and adjust the voltage difference between the gray level voltage of the brightness level where the afterimage is located and the intermediate voltage and the voltage difference between the gray level voltage of the highest brightness level and the intermediate voltage through the binding voltage.

[0040] Among them, the intermediate voltage refers to the center voltage between the gray level voltage of the brightness level where the afterimage is located and the gray level voltage of the highest brightness level.

[0041] In step S2, the specific steps for optimizing and eliminating lateral crosstalk in the image are: adjusting the VCOM voltage so that it is located at the center of the gamma voltage range.

[0042] Gamma voltage is the voltage that controls grayscale brightness. The range of gamma voltage is usually G1-G14, and the optimal state of VCOM voltage is the middle value of G1-G14.

[0043] In step S3, the brightness level grayscale of the afterimage is determined through playback experiments.

[0044] The playback experiment involved playing a video segment for an extended period at a specific brightness level of grayscale, then turning off the display screen and observing whether any ghosting occurred.

[0045] In step S3, during the process of determining the grayscale of the brightness level where the afterimage is located, if the afterimage appears at more than one brightness level grayscale, the grayscale of the brightness level where the different afterimages are located is adjusted separately.

[0046] The binding voltage is adjusted by the voltage difference between the intermediate voltage and the grayscale voltage of the highest brightness level. That is, the larger the voltage difference between the intermediate voltage and the grayscale voltage of the highest brightness level, the larger the binding voltage, and vice versa.

[0047] For example:

[0048] When Rtings is in its optimal state, the binding voltage of each gray level is determined by the L255 gray level voltage. The purpose of this is to ensure symmetry among the gray levels and minimize DC bias. Due to differences in OC processes, lateral crosstalk may occur after the gamma voltage of each binding point. This is because the VCOM voltage is not actually the ideal reference voltage for liquid crystal deflection. The GAMMA voltage controls the gray level brightness and is generally G1 to G14. The optimal VCOM voltage is located at the center value between G0 and G14. With the VCOM voltage fixed, in order to optimize this lateral crosstalk, the center voltage is determined by the L128 gray level voltage. At this time, different binding voltages are tried to reduce the voltage difference between each gray level and the positive and negative frames of the L255 gray level.

[0049] In the Rtings IR experiment, ghosting was found at the L38 gray level. Using the above debugging method, first, the voltage of each gray level was determined based on the L255 gray level voltage. The presence of lateral crosstalk was observed. After determining the voltage of the L128 gray level, the binding voltage of the L38 gray level was increased. The gamma voltage of the L38 gray level was changed to reduce the positive and negative frame voltage difference between the L38 and L255 gray levels. This simultaneously takes into account both Rtings IR and lateral crosstalk. Finally, the Rtings IR and lateral crosstalk were evaluated. If ghosting still exists, it is because the L128 gray level voltage is used as the center voltage, and the bias of the binding voltage of the L38 and L255 gray levels is not symmetrical. The gamma voltage of the L38 gray level needs to be reset until the ghosting is eliminated. Then the optimal CODE can be output, and the debugging is completed.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A debugging method for eliminating grayscale ghosting, the specific steps of which are as follows: Step S1: Determine the gamma voltage of each gray level using the gray level voltage of the highest brightness level; Step S2: Optimize and eliminate lateral crosstalk of the image and determine the grayscale voltage of the current brightness level, using the grayscale voltage of the current brightness level as the center voltage. Step S3: Determine the grayscale brightness level where the afterimage is located, and change the voltage of the grayscale at the brightness level where the afterimage is located to reduce the difference between the positive and negative frame voltage difference between the grayscale at the brightness level where the afterimage is located and the grayscale at the highest brightness level. Step S4: Evaluate the color quantity and lateral crosstalk performance. If there is still a problem with image retention, reset the voltage of the grayscale of the brightness level where the image retention is located until the image retention is eliminated. Step S5: Complete debugging and output the software for saving; The following steps are included before step S1: Step S1 needs to be performed when the voltage of each symmetrical gray level is the same; In step S2, the current brightness level grayscale voltage is the brightness level grayscale voltage when horizontal crosstalk occurs in the image. In step S3, reducing the difference between the positive and negative frame voltage difference between the gray level of the brightness level where the afterimage is located and the gray level of the highest brightness level is: the voltage difference between the gray level voltage of the brightness level where the afterimage is located and the intermediate voltage and the voltage difference between the intermediate voltage and the gray level voltage of the highest brightness level, wherein the intermediate voltage refers to the center voltage between the gray level voltage of the brightness level where the afterimage is located and the gray level voltage of the highest brightness level.

2. The debugging method for eliminating grayscale ghosting according to claim 1, characterized in that: In step S3, the specific implementation of reducing the positive and negative frame voltage difference between the gray level of the brightness level where the afterimage is located and the gray level of the highest brightness level is as follows: add a binding voltage to the gray level of the brightness level where the afterimage is located, and adjust the voltage difference between the gray level voltage of the brightness level where the afterimage is located and the intermediate voltage and the voltage difference between the gray level voltage of the highest brightness level and the intermediate voltage by adjusting the binding voltage.

3. The debugging method for eliminating grayscale ghosting according to claim 1, characterized in that: In step S2, the optimization and elimination of horizontal crosstalk in the image specifically involves adjusting the VCOM voltage so that it is located at the center of the gamma voltage range.

4. The debugging method for eliminating grayscale ghosting according to claim 1, characterized in that: In step S3, the brightness level grayscale of the afterimage is determined through a playback experiment.

5. The debugging method for eliminating grayscale ghosting according to claim 1, characterized in that: In step S3, when determining the grayscale of the brightness level where the afterimage is located, if the afterimage appears at more than one brightness level grayscale, the grayscale of the brightness level where the different afterimages are located is adjusted separately.

6. The debugging method for eliminating grayscale ghosting according to claim 2, characterized in that: The magnitude of the binding voltage is adjusted by the voltage difference between the intermediate voltage and the grayscale voltage of the highest brightness level.

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