TW202116050A - Overdrive method and system - Google Patents

Abstract

An overdrive method includes (a) comparing a current data gray level and a previous data gray level with a predetermined gray level; (b) shifting the current data gray level; (c) repeating step (b) until a frame counter reaches a predetermined frame threshold; and (d) clearing a current overdrive state.

Description

Overdrive method and system

The present invention relates to a display, in particular to an improved overdrive system and method suitable for liquid crystal displays.

A liquid crystal display (LCD) is a type of flat-panel display that uses liquid crystal molecules to control and modulate the intensity of light to display images. The liquid crystal display can be applied to various electronic devices, such as televisions, computers, mobile phones, etc., and can be applied to indoor or outdoor occasions.

The pixels of a liquid crystal display need time to change their display, called response time, which usually refers to the voltage height between the high voltage level and the low voltage level from 10% to 90% (or from 90% to 10%). ) The time required for transition. The response time is generally measured in milliseconds (ms), and the smaller the value, the faster the change. In order to reduce the reaction time, that is, to speed up the transition, an overdrive method is generally used for display. However, the over-driving method of the conventional liquid crystal display will form image artifacts or smears, thereby causing the degradation of the image display quality. In addition, the response time of the liquid crystal display using the traditional overdrive method still has room for improvement to reduce the space.

Therefore, a novel mechanism is urgently needed to effectively reduce the response time of the liquid crystal display to accelerate the transition of image display and improve the quality of image display.

In view of the foregoing, one of the objectives of the embodiments of the present invention is to provide an overdrive system and method suitable for liquid crystal displays, which can effectively reduce the response time of the liquid crystal display and improve image clarity.

According to an embodiment of the present invention, the overdrive system includes a grayscale determination unit, an overdrive state detection unit, and a grayscale modification unit. The gray level determination unit determines the data gray level of the image data. The over-driving state detection unit determines the over-driving state according to the data gray level. The gray level modification unit performs the corresponding data gray level modification according to the over-driving state. The gray level modification unit performs the following steps: (a) compare the current data gray level with the previous data gray level and a preset gray level value; (b) offset the current data gray level; (c) repeat the step (b) ) Until the count value of the frame has reached the preset frame threshold; and (d) Clear the current overdrive state.

The first figure shows a system block diagram of a liquid crystal display 10 according to an embodiment of the present invention. In this embodiment, the liquid crystal display 10 may include a display panel 11, which may include a plurality of pixels arranged in a matrix. The liquid crystal display 10 of this embodiment may include a gate driver (also called a scan driver) 12 for sequentially turning on at least one column of pixels of the display panel 11. The liquid crystal display 10 may include a source driver (also referred to as a data driver) 13 for generating a corresponding voltage of the image data to the display panel 11 to display the image on the display panel 11. The liquid crystal display 10 may include a timing controller (TCON) 14 for controlling the gate driver 12 and the source driver 13.

The second diagram A shows a block diagram of an overdrive (OD) system 100 according to an embodiment of the present invention, which can be implemented in the timing controller 14 of the first diagram, but is not limited thereto. In this embodiment, the overdriving system 100 may include an overdriving unit 101 for performing overdriving of image data. A conventional overdriving technique can be used, and the details will not be repeated. According to one of the features of this embodiment, the overdrive system 100 may include an overdrive response time improvement system 102 to improve the output of the overdrive unit 101. The overdrive system 100 of this embodiment may include a gamma correction unit 103, which receives the output of the overdrive response time improvement system 102 to perform gamma correction. Traditional gamma correction techniques may be used, and the details are not given. Go into details.

The second diagram B shows a detailed block diagram of the overdrive response time improvement system 102 of the second diagram A. In this embodiment, the overdrive response time improvement system 102 may include a gray level determining unit 1021 for determining the data gray level of the image data. For example, if the image data includes red, green, and blue data, the gray level determining unit 1021 determines the maximum gray level of the red, green, and blue data of a pixel as the data gray level of the pixel. The overdriving response time improvement system 102 of this embodiment may include an overdriving state detecting unit 1022, which determines the overdriving state according to the gray scale of the data.

The third figure shows a flow chart of the overdrive method 200 of the liquid crystal display according to the embodiment of the present invention, which is used to determine whether to activate the overdrive response time improvement mechanism, which can be implemented in the overdrive state detection unit 1022 of the second figure B.

In this embodiment, two flags are used to indicate the over-driving state: when the low-to-high (L2H) flag is active (for example, the L2H flag=1), it indicates the low-to-high over-driving state; when the high-to-low (H2L) flag is active When the flag is active (for example, the H2L flag=1), it indicates a high-to-low overdrive state.

When it is not in the low-to-high overdrive state (that is, the L2H flag = 0) (step 21A), proceed to step 22A to determine whether the previous data gray level ORGGL (Pre) and the current data gray level ORGGL (Cur) are less than the preset It is assumed that the low gray scale value L2Hmin_gray becomes greater than the preset high gray scale value L2Hmax_gray. In one example, the preset low gray level value L2Hmin_gray is 1, and the preset high gray level value L2Hmax_gray is 250. If the result of step 22A is yes, proceed to step 23A to increment the transition count value (for example, add 1). Repeat steps 22A and 23A until the entire sub-pixel has been inspected (step 24A).

Next, in step 25A, it is determined whether the obtained transition count value has reached the preset transition threshold. In this embodiment, in order to allow for variability, in step 25A, it is checked whether the transition count value falls between the preset transition threshold and the positive/negative tolerance (that is, the transition threshold + the tolerance and the transition Critical value-tolerance limit). If the result of step 25A is yes, then in step 26A, the low-to-high (L2H) flag is set to active (for example, the L2H flag=1), indicating a low-to-high overdrive state.

The above steps 21A to 26A are used to determine whether to activate the low-to-high (L2H) overdrive mechanism. In a similar situation, steps 21B to 26B are used to determine whether to activate the high-to-low (H2L) overdrive mechanism, as described below.

When it is not in the high-to-low overdrive state (that is, the H2L flag=0) (step 21B), or the result of step 22A is no, then go to step 22B to determine the previous data gray level ORGGL (Pre) and the current data gray Whether the level ORGGL(Cur) is changed from greater than the preset high gray level H2Lmax_gray to less than the preset low gray level H2Lmin_gray. In one example, the preset high grayscale value H2Lmax_gray is 250, and the preset low grayscale value H2Lmin_gray is 1. It is worth noting that the low preset gray level H2Lmin_gray (of step 22B) can be the same or different from the low preset gray level L2Hmin_gray (of step 22A), and the high preset gray level H2Lmax_gray (of step 22B) can be the same or It is different from the preset high gray level L2Hmax_gray (of step 22A). If the result of step 22B is yes, proceed to step 23B to increment the transition count value (for example, add 1). Repeat steps 22B and 23B until the entire sub-pixel has been inspected (step 24B).

Next, in step 25B, it is determined whether the obtained transition count value has reached the preset transition threshold. It should be noted that the preset H2L transition threshold (in step 25B) can be the same or different from the preset L2H transition threshold (in step 25A). In this embodiment, in order to allow for variability, in step 25B, it is checked whether the transition count value falls between the preset transition threshold and the positive/negative tolerance (that is, the transition threshold + the tolerance and the transition Critical value-tolerance limit). If the result of step 25B is yes, then in step 26B, the high-to-low (H2L) flag is set to active (for example, the H2L flag=1), which indicates the high-to-low overdrive state.

The overdrive response time improvement system 102 of FIG. 2B may include a gray-level modification unit 1023, and according to the over-drive state determined by the over-drive state detection unit 1022, the corresponding data gray-level modification is performed accordingly. That is, when it is in a low-to-high overdrive state (for example, the L2H flag=1), the low-to-high data grayscale is modified; when it is in a high-to-low overdrive state (for example, the H2L flag=1), then Carry out high to low data grayscale modification.

Fig. 4A shows a flow chart of an overdrive method 300 of a liquid crystal display according to an embodiment of the present invention, which is used to perform low-to-high (L2H) data gray-level modification, which can be implemented in the gray-level modification unit 1023 of Fig. 2B .

When it is in the low-to-high (L2H) overdrive state (that is, the L2H flag=1) (step 31), proceed to step 32 to determine whether the current data gray level ORGGL (Cur) and the previous data gray level ORGGL (Pre) are greater than The default high grayscale value is L2Hmax_gray. If the result of step 32 is yes, go to step 33, otherwise go to step 37 to set the low-to-high (L2H) flag to inactive (for example, the L2H flag=0), that is, to clear the current overdrive state.

In step 33, the (first frame) offset is subtracted from the current data gray level ORGGL (Cur) to perform the current over-driving gray level ODGL (Cur) offset. Next, in step 34, the count value of the frame is incremented. In step 35, it is determined whether the count value of the frame has reached the preset frame threshold. If the result of step 35 is no, then repeat steps 33 to 34, otherwise go to step 36. In one example, step 33 is repeated three times, wherein the first frame offset, the second frame offset, and the third frame offset are successively decreased, for example, 10, 7, and 3 respectively. The fourth diagram B illustrates the overdriving gray scale generated by the overdriving method 300 according to the fourth diagram A. When step 33 is performed for the first time, the value of the overdrive gray level is 245 (=255-10); when step 33 is performed for the second time, the value of the overdrive gray level is 248 (=255-7); When step 33 is executed three times, the value of the overdrive gray level is 252 (=255-3).

Next, in step 36, the overdrive gray level is sequentially fine-tuned to increase the overdrive gray level (for example, the step is 1) until the maximum gray level (for example, 255). As illustrated in Fig. 4B, after subtracting the third frame offset, the overdrive gray level is 252, and the fine-tuning increases are sequentially 253, 254, and 255. Step 36 can be implemented by the grayscale dimming unit 1024 of the second B image. Finally, proceed to step 37 to set the low-to-high (L2H) flag as inactive (for example, the L2H flag=0).

Fig. 5A shows a flow chart of an overdrive method 500 of a liquid crystal display according to an embodiment of the present invention, which is similar to the overdrive method 300 of Fig. 4A, but is used to perform high-to-low (H2L) data grayscale modification. It can be implemented in the gray level modification unit 1023 of the second B image.

When in the high-to-low (H2L) overdrive state (that is, the H2L flag=1) (step 51), go to step 52 to determine whether the current data gray level ORGGL (Cur) and the previous data gray level ORGGL (Pre) Less than the preset low gray level H2Lmin_gray. If the result of step 53 is yes, go to step 53, otherwise go to step 57 to set the high-to-low (H2L) flag to inactive (for example, the H2L flag=0), that is, to clear the current overdrive state.

In step 53, the current data gray level ORGGL (Cur) is added to the (first frame) offset to perform the current overdrive gray level ODGL (Cur) offset. Then, in step 54, the count value of the frame is incremented. In step 55, it is determined whether the count value of the frame has reached the preset frame threshold. If the result of step 55 is no, repeat steps 53 to 54; otherwise, proceed to step 56. In one example, step 53 is repeated three times, where the first frame offset, the second frame offset, and the third frame offset are successively decreased, for example, 10, 7, and 3 respectively. It is worth noting that the offset in step 53 may be the same or different from the offset in step 33. Fig. 5B illustrates the overdriving gray scale generated by the overdriving method 500 of Fig. 5A. When step 53 is performed for the first time, the value of the overdrive gray level is 10 (=0+10); when step 53 is performed for the second time, the value of overdrive gray level is 7 (=0+7); When step 53 is executed three times, the value of the overdrive gray level is 3 (=0+3).

Next, in step 56, sequentially fine-tune to reduce the overdrive gray level (for example, the step is 1) until the minimum gray level (for example, 0). As illustrated in Figure 5B, after adding the third frame offset, the overdrive gray level is 3, and the fine-tuning reduction is sequentially 2, 1, 0. Step 56 can be implemented by the grayscale dimming unit 1024 of the second B image. Finally, proceed to step 57 to set the high-to-low (H2L) flag to be inactive (for example, the H2L flag=0).

The above descriptions are only the preferred embodiments of the present invention, and are not intended to limit the scope of patent application of the present invention; all other equivalent changes or modifications made without departing from the spirit of the invention should be included in the following Within the scope of the patent application.

10: LCD display 11: Display panel 12: Gate driver 13: Source driver 14: Timing controller 100: Overdrive system 101: Overdrive unit 102: Overdrive reaction time improvement system 1021: Grayscale determination unit 1022: Overdrive status detection unit 1023: Grayscale modification unit 1024: Grayscale fine-tuning unit 103: Gamma correction unit 200: Overdrive method 21A:L2H flag=0 21B: H2L flag=0 22A: ORGGL(Pre)>=L2Hmin_gray and ORGGL(Cur)>=L2Hmax_gray 22B: ORGGL(Pre)>=H2Lmin_gray and ORGGL(Cur)>=H2Lmax_gray 23A: L2H transition count value = L2H transition count value + 1 23B: H2L transition count value = H2L transition count value + 1 24A: Has the entire sub-pixel been viewed 24B: Whether the entire sub-pixel has been viewed 25A: L2H transition count value>=L2H transition critical value-tolerance limit and L2H transition count value>=L2H transition critical value + tolerance limit 25B: H2L transition count value >= H2L transition critical value-tolerance limit and H2L transition count value>=H2L transition critical value + tolerance limit 26A: L2H flag=1 26B: H2L flag=1 300: Overdrive method 31: L2H flag=1 32: ORGGL(Cur)>=L2Hmax_gray ORGGL(Pre)>=L2Hmax_gray 33: ODGL(Cur)=ORGGL(Cur)-(frame) offset 34: The count value of the frame = the count value of the frame + 1 35: Whether the count value of the frame has reached the threshold of the frame 36: Sequentially fine-tuned to increase the overdrive gray level 37: L2H flag=0 500: Overdrive method 51: H2L flag=1 52: ORGGL(Cur)>=L2Hmin_gray ORGGL(Pre)>=L2Hmin_gray 53: ODGL(Cur)=ORGGL(Cur)+(frame) offset 54: The count value of the frame = the count value of the frame + 1 55: Whether the count value of the frame has reached the threshold of the frame 56: Sequentially fine-tuned to reduce overdrive grayscale 57: H2L flag=0 L2H: low to high H2L: high to low ORGGL(Pre): Grayscale of previous data ORGGL(Cur): current data grayscale L2Hmin_gray: preset low gray level L2Hmax_gray: preset high grayscale value H2Lmin_gray: preset low gray level H2Lmax_gray: preset high grayscale value ODGL(Cur): current overdrive grayscale

The first figure shows a system block diagram of a liquid crystal display according to an embodiment of the present invention. Figure 2A shows a block diagram of an overdrive system according to an embodiment of the present invention. Figure 2B shows a detailed block diagram of the overdrive response time improvement system of Figure 2A. The third figure shows a flowchart of an overdrive method of a liquid crystal display according to an embodiment of the present invention. FIG. 4A shows a flowchart of an overdrive method of a liquid crystal display according to an embodiment of the present invention, which is used to perform low-to-high (L2H) data grayscale modification. The fourth diagram B illustrates the overdrive gray scale generated by the overdriving method of the fourth diagram A. FIG. 5A shows a flowchart of an overdrive method of a liquid crystal display according to an embodiment of the present invention, which is used to perform high-to-low (H2L) data grayscale modification. Fig. 5B illustrates the overdrive gray scale generated according to the overdrive method of Fig. 5A.

102: Overdrive reaction time improvement system

1021: Grayscale determination unit

1022: Overdrive status detection unit

1023: Grayscale modification unit

1024: Grayscale fine-tuning unit

Claims (20)

An overdrive method, including: (a) Compare the current data gray level with the previous data gray level and a preset gray level value; (b) Offset the gray scale of the current data; (c) Repeat step (b) until the count value of the frame reaches the preset frame threshold; and (d) Clear the current overdrive status. According to the overdriving method described in item 1 of the scope of patent application, if it is in a low to high overdriving state, the preset grayscale value is a preset high grayscale value, and step (a) includes: Determine whether the current data gray level and the previous data gray level are greater than the preset high gray level. According to the overdrive method described in item 2 of the scope of patent application, if it is in a low to high overdrive state, step (b) includes: Subtract the frame offset from the current data gray level. According to the overdrive method described in item 1 of the scope of patent application, if it is in a high-to-low overdrive state, the preset grayscale value is a preset low grayscale value, and step (a) includes: It is determined whether the current data gray level and the previous data gray level are less than the preset low value of the gray level. According to the overdrive method described in item 4 of the scope of patent application, if it is in a high-to-low overdrive state, step (b) includes: Add the current data gray level to the offset of the frame. According to the overdrive method described in item 1 of the scope of the patent application, the offset is different each time the step (b) is executed. According to the overdrive method described in item 6 of the scope of patent application, the offset is sequentially decreased. According to the overdrive method described in item 1 of the scope of patent application, between step (c) and step (d), it further includes: Fine-tune the overdrive gray level. According to the overdrive method described in item 8 of the scope of patent application, if it is in the low-to-high overdrive state, the overdrive gray scale is sequentially increased until the maximum gray scale; if it is in the high to low overdrive state, then sequentially Fine-tuning reduces the overdrive gray level to the minimum gray level. According to the overdrive method described in item 1 of the scope of patent application, the determination of the overdrive state includes: When it is not in a low-to-high overdrive state, it is determined whether the previous data gray level and the current data gray level are changed from a low value less than the preset gray level to a high value greater than the preset gray level; When it is not in a high-to-low overdrive state, it is determined whether the previous data gray level and the current data gray level are changed from a high value greater than the preset gray level to a low value less than the preset gray level. An overdrive system, including: A grayscale determination unit for determining the data grayscale of the image data; An over-driving state detecting unit, determining the over-driving state according to the gray scale of the data; A gray-scale modification unit is adapted to modify the corresponding data gray-scale according to the over-driving state, wherein the gray-scale modification unit executes the following steps: (a) Compare the current data gray level with the previous data gray level and a preset gray level value; (b) Offset the gray scale of the current data; (c) Repeat step (b) until the count value of the frame reaches the preset frame threshold; and (d) Clear the current overdrive status. According to the overdrive system described in item 11 of the scope of patent application, if it is in a low to high overdrive state, the preset grayscale value is a preset high grayscale value, and step (a) includes: Determine whether the current data gray level and the previous data gray level are greater than the preset high gray level. According to the overdrive system described in item 12 of the scope of patent application, if it is in a low to high overdrive state, step (b) includes: Subtract the frame offset from the current data gray level. According to the overdrive system described in item 11 of the scope of patent application, if it is in a high-to-low overdrive state, the preset grayscale value is a preset low grayscale value, and step (a) includes: It is determined whether the current data gray level and the previous data gray level are less than the preset low value of the gray level. According to the overdrive system described in item 14 of the scope of patent application, if it is in a high-to-low overdrive state, step (b) includes: Add the current data gray level to the offset of the frame. According to the overdrive system described in item 11 of the scope of patent application, the offset is different every time step (b) is executed. According to the overdrive system described in item 16 of the scope of the patent application, the offset decreases in order. According to the overdrive system described in item 11 of the scope of patent application, it further includes a grayscale fine-tuning unit, which is executed between step (c) and step (d): Fine-tune the overdrive gray level. According to the overdrive system described in item 18 of the scope of patent application, if it is in a low-to-high overdrive state, the grayscale fine-tuning unit sequentially fine-tunes to increase the overdrive grayscale until the maximum grayscale; if it is in a high-to-low overdrive state State, the gray-scale fine-tuning unit sequentially fine-tunes to reduce the over-driving gray-scale until the minimum gray-scale. According to the overdrive system described in item 11 of the scope of patent application, the overdrive state detection unit executes: When it is not in a low-to-high overdrive state, it is determined whether the previous data gray level and the current data gray level are changed from a low value less than the preset gray level to a high value greater than the preset gray level; When it is not in a high-to-low overdrive state, it is determined whether the previous data gray level and the current data gray level are changed from a high value greater than the preset gray level to a low value less than the preset gray level.

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