CN115831069A

CN115831069A - Display control circuit with dynamic backlight adjustment mechanism and backlight control method thereof

Info

Publication number: CN115831069A
Application number: CN202111092008.1A
Authority: CN
Inventors: 陈立昂
Original assignee: Realtek Semiconductor Corp
Current assignee: Realtek Semiconductor Corp
Priority date: 2021-09-17
Filing date: 2021-09-17
Publication date: 2023-03-21

Abstract

The invention provides a backlight control method with a dynamic backlight adjusting mechanism, which is applied to a display control circuit. The backlight control method comprises the following steps: obtaining the frame refreshing time length of the previous frame; when the current frame starts, controlling a backlight module to output stroboscopic backlight at backlight starting time; when the actual picture display time reaches the frame refreshing time length and the next frame is not started yet, controlling the backlight module to output constant-brightness backlight until the next frame is started; and when the actual picture display time does not reach the frame refreshing time length and the next frame starts, controlling the backlight module to output the constant-brightness backlight until the next frame starts after the frame refreshing time length is reached.

Description

Display control circuit with dynamic backlight adjustment mechanism and backlight control method thereof

Technical Field

The present invention relates to display technologies, and in particular, to a display control circuit with a dynamic backlight adjustment mechanism and a backlight control method thereof.

Background

In a conventional liquid crystal display (LCD monitor), since a general frame refresh method belongs to hold-type display (hold-type display), when an object moves on a screen, motion blur is caused because a naked eye tracking speed is different from a screen refresh speed.

In order to solve the motion blur, a stroboscopic backlight (stroboscopic backlight) is used for the liquid crystal screen, that is, the backlight module is turned on and off instantly to block the black of the image, so that the blur phenomenon observed by naked eyes is reduced. However, when a Variable Refresh Rate (VRR) is applied, the backlight module may have a flicker phenomenon due to difficulty in maintaining the brightness of the entire screen due to the dynamic change of the frame time.

Disclosure of Invention

In view of the problems of the prior art, it is an object of the present invention to provide a display control circuit with a dynamic backlight adjustment mechanism and a backlight control method thereof, so as to improve the prior art.

The invention includes a backlight control method with dynamic backlight adjustment mechanism, which is applied to a display control circuit, the display control circuit is configured to receive an image signal from an image source and accordingly generate a plurality of frames to a display panel for displaying and generate a backlight control signal to a backlight module for switching, the backlight control method comprises the following steps: obtaining, by a display control circuit, a frame refresh time length of a previous frame; when the current frame starts, the display control circuit controls the backlight module to output stroboscopic backlight with preset brightness at the backlight starting time; judging whether the actual picture display time of the current frame reaches the frame refreshing time length and whether the next frame starts or not by the display control circuit; when the actual picture display time reaches the frame refreshing time length and the next frame is not started, the display control circuit controls the backlight module to output the constant-brightness backlight with the compensation brightness so as to maintain the preset brightness until the next frame is started; and when the actual picture display time does not reach the frame refreshing time length and the next frame starts, the display control circuit controls the backlight module to output the constant-brightness backlight with the compensation brightness after reaching the frame refreshing time length so as to maintain the preset brightness until the next frame starts.

The present invention also includes a display control circuit having a dynamic backlight adjustment mechanism, electrically coupled to the display panel and the backlight module. Configuring a display control circuit to: receiving an image signal from an image source, generating a plurality of frames to a display panel for displaying and generating a backlight control signal to a backlight module for switching: obtaining the frame refreshing time length of the previous frame; when the current frame starts, controlling a backlight module to output stroboscopic backlight with preset brightness at backlight starting time; judging whether the actual picture display time of the current frame reaches the frame refreshing time length and whether the next frame starts; when the actual picture display time reaches the frame refreshing time length and the next frame is not started yet, controlling the backlight module to output constant-brightness backlight with compensation brightness so as to maintain the preset brightness until the next frame is started; and when the actual picture display time does not reach the frame refreshing time length and the next frame starts, controlling the backlight module to output the constant-brightness backlight with the compensation brightness after reaching the frame refreshing time length so as to maintain the preset brightness until the next frame starts.

With regard to the features, implementation and efficacy of the present application, preferred embodiments will now be described in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a block diagram illustrating a display device according to an embodiment of the present invention;

FIG. 2 is a timing diagram illustrating operations associated with a display device according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating an actual output waveform of the display control circuit when the backlight module outputs a constant-brightness backlight according to an embodiment of the present invention;

FIG. 4 is a timing diagram illustrating operations associated with a display device according to another embodiment of the present invention; and

fig. 5 is a flowchart illustrating a backlight control method with a dynamic backlight adjustment mechanism according to an embodiment of the invention.

Detailed Description

An object of the present invention is to provide a display control circuit with a dynamic backlight adjustment mechanism and a backlight control method thereof, which enable a backlight module to maintain the same average brightness by the dynamic backlight adjustment mechanism when a refresh frequency of a frame changes through operation of the display control circuit, thereby implementing stroboscopic backlight.

Please refer to fig. 1. Fig. 1 is a block diagram illustrating a display device 100 according to an embodiment of the present invention. The display device 100 includes: a display control circuit 110 with a dynamic backlight adjustment mechanism, a display panel 120 and a backlight module 130.

In one embodiment, the display control circuit 110 is a scaler (scaler), but the invention is not limited thereto. The display control circuit 110 is electrically coupled to the display panel 120 and the backlight module 130 inside the display device 100, and is coupled to an image source HS (e.g., a host) on the display device 100. The display control circuit 110 IS configured to receive an image signal IS from an image source HS, and accordingly generate a plurality of frames FD to the display panel 120 for displaying and generate a backlight control signal BS to the backlight module 130 for switching. In an embodiment, the display control circuit 110 is coupled to the display panel 120 through a display driving chip, and the display control circuit 110 is coupled to the backlight module 130 through a backlight driving chip, but the invention is not limited thereto.

In another embodiment, the display panel 120 and the backlight module 130 are integrated in the same display module, but the invention is not limited thereto.

In more detail, the display control circuit 110 causes the display panel 120 to receive the frame FD to display a plurality of frames in different frame refresh times according to a frame refresh frequency. The frame refresh time length of each frame is the reciprocal of the corresponding frame refresh frequency. In one embodiment, the frame refresh frequency may vary according to the demand, and therefore the frame refresh time length will also vary according to the variation of the frame refresh frequency.

On the other hand, to solve the motion blur caused by the mismatch between the eye tracking speed and the display refresh speed, the display control circuit 110 may use a strobe backlight (strobe backlight) mode to control the backlight module 130 through the backlight control signal BS, so that the corresponding frame is turned on during the backlight on time of each refresh time, so as to provide the light source to light the display panel 120 and turn off outside the backlight on time.

Referring to fig. 2, the operation of the dynamic backlight adjustment mechanism of the display device 100 is described in detail.

Please refer to fig. 2. FIG. 2 is a timing diagram illustrating operations of the display device 100 according to an embodiment of the invention.

In fig. 2, the operation timing of the display panel 120 and the operation timing of the backlight module 130 are mainly shown. Fig. 2 shows the frame refresh times TP1 to TP5 of the frames FR1 to FR5 with respect to the operation timing of the display panel 120. With respect to the operation timing sequence of the backlight module 130, fig. 2 shows backlight-on intervals corresponding to a plurality of backlight-on times TB1 to TB5, wherein the height of the backlight-on intervals represents the brightness of the backlight module 130.

As described above, the display control circuit 110 can generate different frames FR 1-FR 5 in the frame FD within the frame refresh time TP 1-TP 5 according to the frame refresh frequency after receiving the video signal IS, wherein the refresh time starting points TI 1-TI 5 of the refresh time TP 1-TP 5 of each frame are defined by the vertical synchronization signal (V-sync) (as shown by the upper signals in FIG. 2). Each of the refresh times TP1 to TP5 has a frame refresh time length RL1 to RL5, and the reciprocal of the frame refresh time length RL1 to RL5 corresponds to the frame refresh frequency.

Moreover, the display control circuit 110 can control the backlight module 130 to be turned on for the backlight-on time TB1 to TB 5. The starting time lengths IL 1-IL 5 are respectively set between the backlight time starting points BI 1-BI 5 of the backlight starting times TB 1-TB 5 and the corresponding refreshing time starting points TI 1-TI 5 of the frame refreshing times TP 1-TP 5. The backlight turn-on times TB1 to TB5 have turn-on time lengths BL1 to BL5.

In the present embodiment, the frames FR1 and FR2 are displayed at a first frame refresh rate, and the frames FR3 to FR5 are displayed at a second frame refresh rate, which is less than the first frame refresh rate. Therefore, the frame refresh time length RL3 to RL5 of each frame FR3 to FR5 is greater than the frame refresh time length RL1 and RL2 of each frame FR1 and FR 2.

The following description will be given by taking the frame FR3 as the current frame as an example. In such a case, the frame FR2 is the previous frame and the frame FR4 is the next frame.

First, the display control circuit 110 obtains the frame refresh time length RL2 of the previous frame FR 2.

In one embodiment, the display control circuit 110 accumulates the horizontal synchronization signal (H-sync, not shown) of the previous frame RF2 to obtain the frame refresh time length RL2.

In another embodiment, the display control circuit 110 can also directly extract the refresh rate information (not shown) from the image signal IS to obtain the frame refresh time length RL2 if the capability of the image source HS in fig. 1 allows.

At the beginning of the current frame FR3, the display control circuit 110 controls the backlight module 130 to output the stroboscopic backlight with the preset brightness DB during the backlight on time TB 3. The plurality of time parameters of the backlight turn-on time TB3 are set relative to the frame refresh time length RL2 according to a plurality of preset time scale parameters.

In one embodiment, the time parameter includes a start time length and an on time length, and the preset time ratio parameter includes a start time ratio and an on time ratio.

The start time ratio determines a ratio between a length of a refresh time start point of the backlight turn-on time with respect to a refresh time start point of a frame and a length of a frame refresh time. Taking the current frame FR2 as an example, the ratio is a ratio between the starting time length IL2 of the backlight time starting point BI2 of the backlight on-time TB2 to the starting time length TI2 of the refresh time TP2 of the frame and the frame refresh time length RL2 of the frame refresh time TP2, i.e., IL2/RL2.

The on-time ratio is the ratio between the length of the backlight on-time and the length of the frame refresh time. Taking the current frame FR3 as an example, the ratio between the on-time length BL2 of the backlight on-time TB2 and the frame refresh time length RL2 of the frame refresh time TP2, i.e. BL2/RL2.

In one embodiment, in order to make the backlight provided by the backlight module 130 have a uniform brightness (e.g., the preset brightness DB), each frame is set with respect to the refresh time length of the frame by a fixed preset time scale parameter.

Therefore, corresponding to the current frame FR3, the display control circuit 110 sets the start time length IL3 for the refresh time length RL2 of the frame according to the start time ratio, so that the start time length IL3 is equal to the start time length IL 2. And, corresponding to the current frame FR3, the display control circuit 110 sets the on-time length BL3 for the refresh time length RL2 of the frame according to the on-time ratio, so that the on-time length BL3 is equal to the on-time length BL2.

Then, the display control circuit 110 determines whether the actual frame display time of the current frame FR3 reaches the frame refresh time length and whether the next frame FR4 starts.

As shown IN fig. 2, the frame refresh time TP3 corresponding to the frame FR3 includes a first section IN1 having a length equal to the frame refresh time length RL2. When the first interval IN1 is over, the display control circuit 110 determines that the actual image display time of the current frame FR3 reaches the frame refresh time length RL2 and the next frame FR4 is not yet started, and controls the backlight module 130 to output the constant-brightness backlight with the compensation brightness to maintain the preset brightness until the next frame FR4 is started.

Therefore, the backlight module 130 outputs the constant-brightness backlight having the compensation brightness AB during the second interval IN2 between the end of the first interval IN1 and the start of the frame FR4 at the frame refresh time TP 3. IN one embodiment, the magnitude of the compensation luminance AB is equal to the magnitude of the average luminance of the stroboscopic backlight output IN the first interval IN1 during the backlight-on time TB 3.

Please refer to fig. 3. Fig. 3 is a diagram illustrating an actual output waveform 300 when the display control circuit 110 controls the backlight module 130 to output a constant-brightness backlight according to an embodiment of the invention.

As shown in fig. 3, when the display control circuit 110 controls the backlight module 130 to output the constant-brightness backlight with the compensation brightness, the actual output waveform 300 of the constant-brightness backlight can be output according to a Pulse Width Modulation (PWM) waveform greater than a preset frequency, and the PWM waveform has the same duty cycle as the stroboscopic backlight. The compensation luminance AB in fig. 2 is an equivalent value of the luminance of the actual output waveform 300.

By using such a constant-luminance backlight that can vary with the actual screen display time, the luminance of the entire screen can be maintained constant without flickering.

After the next frame FR4 is started, the display control circuit 110 sets the frame FR4 as the current frame and sets the frame FR3 as the previous frame for processing.

At this time, the display control circuit 110 obtains the frame refresh time length RL3 of the previous frame FR 3. At the beginning of the current frame FR4, the display control circuit 110 controls the backlight module 130 to output the stroboscopic backlight with the preset brightness DB at the backlight on-time TB4, wherein a plurality of time parameters of the backlight on-time TB4 are set according to a plurality of preset time scale parameters relative to the refresh time length RL3 of the frame. The content of the preset time scale parameter and the setting of the time parameter are different from those described above, and are not described herein again.

Therefore, corresponding to the current frame FR4, the display control circuit 110 sets the start time length IL4 for the refresh time length RL3 of the frame according to the start time ratio, such that the start time length IL4 is greater than the start time length IL3. In addition, corresponding to the current frame FR4, the display control circuit 110 sets the on-time length BL4 for the refresh time length RL3 of the frame according to the on-time ratio, so that the on-time length BL4 is greater than the on-time length BL3.

However, since the start time ratio and the on time ratio are fixed, the average brightness of the backlight module 130 corresponding to the frames FR4 and FR3 is substantially the same.

Then, the display control circuit 110 determines whether the actual frame display time of the current frame FR4 reaches the frame refresh time length and whether the next frame FR5 starts.

The display control circuit 110 does not perform compensation when the actual screen display time reaches the frame refresh time length RL4 and the next frame FR5 starts. After the next frame FR5 starts, the display control circuit 110 may continue to set the frame FR5 as the current frame and set the frame FR4 as the previous frame for processing, which is not described herein again.

Please refer to fig. 4. FIG. 4 is a timing diagram illustrating operations of the display apparatus 100 according to another embodiment of the present invention.

Similar to fig. 2, fig. 4 shows the refresh times TP1 to TP5 of the frames FR1 to FR5 and the backlight on-periods of the backlight on-periods TB1 to TB3 and TB5, wherein the height of the backlight on-periods represents the brightness of the backlight module 130. The definitions of the parameters related to the refresh times TP1 to TP5 and the backlight turn-on times TB1 to TB3 and TB5 are the same as those in fig. 2, and are not described herein again.

In the present embodiment, the frames FR1 and FR2 are displayed at a first frame refresh rate, and the frames FR3 to FR5 are displayed at a second frame refresh rate, wherein the second frame refresh rate is greater than the first frame refresh rate. Therefore, the frame refresh time length RL3 to RL5 of each frame FR3 to FR5 is smaller than the frame refresh time length RL1 and RL2 of each frame FR1 and FR 2.

The following description will first use the frame FR3 as the current frame as an example. In such a case, frame FR2 is the previous frame and frame FR4 is the next frame.

First, the display control circuit 110 obtains the frame refresh time length RL2 of the previous frame FR 2. At the beginning of the current frame FR3, the display control circuit 110 controls the backlight module 130 to output the stroboscopic backlight with the preset brightness DB at the backlight on-time TB3, wherein a plurality of time parameters of the backlight on-time TB3 are set according to a plurality of preset time scale parameters relative to the refresh time length RL2 of the frame. The content of the preset time scale parameter and the setting of the time parameter are different from those described above, and are not described herein again.

Then, the display control circuit 110 determines whether the actual frame display time of the current frame FR3 reaches the frame refresh time duration and whether the next frame FR4 starts.

As shown IN fig. 4, the frame refresh times TP3 and TP4 corresponding to the frames FR3 and FR4 include a first section IN1 having a length equal to the frame refresh time length RL2. When the next frame FR4 starts, the display control circuit 110 determines that the actual frame display time has not reached the frame refresh time length RL2 and the next frame FR4 starts, and controls the backlight module 130 to output the constant-brightness backlight with the compensation brightness after reaching the frame refresh time length RL2 to maintain the preset brightness until the next frame FR5 starts.

Therefore, the backlight module 130 outputs the constant-brightness backlight having the compensation brightness AB during the second interval IN2 between the end of the first interval IN1 and the start of the frame FR5 at the frame refresh time TP 3. The output mode of the constant-brightness backlight and the setting of the compensation brightness AB are the same as those described above, and are not described herein again.

After the start of the next frame FR5, the display control circuit 110 sets the frame FR5 as the current frame and sets the frame FR4 as the previous frame for processing.

At this time, the display control circuit 110 obtains the frame refresh time length RL4 of the previous frame FR 4. At the beginning of the current frame FR5, the display control circuit 110 controls the backlight module 130 to output the stroboscopic backlight with the preset brightness DB at the backlight on-time TB4, wherein a plurality of time parameters of the backlight on-time TB5 are set according to a plurality of preset time scale parameters relative to the refresh time length RL4 of the frame.

Therefore, corresponding to the current frame FR5, the display control circuit 110 sets the start time length IL5 for the frame refresh time length RL4 according to the start time ratio, so that the start time length IL5 is smaller than the start time length IL3. In addition, the display control circuit 110 sets the on-time BL5 corresponding to the refresh time RL4 of the current frame FR5 according to the on-time ratio, so that the on-time BL5 is smaller than the on-time BL3. However, since the start time ratio and the on time ratio are fixed, the average brightness of the backlight module 130 corresponding to the frame FR5 and the first interval IN1 is substantially the same.

Then, if the frame FR5 has a subsequent frame, the display control circuit 110 may set the next frame as the current frame and set the frame FR5 as the previous frame for processing, which is not described herein again.

The display device of the invention can make the backlight module maintain the same average brightness by a dynamic backlight adjusting mechanism when the refresh frequency of the frame changes through the operation of the display control circuit, thereby realizing stroboscopic backlight.

Please refer to fig. 5. Fig. 5 is a flowchart illustrating a backlight control method 500 with a dynamic backlight adjustment mechanism according to an embodiment of the invention.

In addition to the foregoing devices, the present invention further discloses a backlight control method 500, which is applied to the display device 100 of fig. 1, for example, but not limited thereto. One embodiment of a backlight control method 500 is shown in FIG. 5, and includes the following steps:

in step S510, the frame refresh time length of the previous frame is obtained by the display control circuit 110.

In step S520, the display control circuit 110 controls the backlight module 130 to output a stroboscopic backlight with a preset brightness according to the frame refresh time length and a plurality of preset time scale parameters at the beginning of the current frame.

In step S530, the display control circuit 110 determines whether the actual frame display time of the current frame reaches the frame refresh time length.

In step S540, the display control circuit 110 determines whether the next frame starts when the actual frame display time reaches the frame refresh time length.

In step S550, when the actual frame display time has reached the frame refresh time duration and the next frame has not yet started, the display control circuit 110 controls the backlight module 130 to output the constant-brightness backlight with the compensation brightness to maintain the preset brightness until the next frame starts.

In step S555, the display control circuit 110 sets the current frame as the previous frame and the next frame as the current frame at the start of the next frame. The flow further returns to step S510 for the backlight control method 500.

In step S560, the display control circuit 110 does not perform compensation when the actual frame display time has reached the frame refresh time length and the next frame starts.

In step S565, the display control circuit 110 sets the current frame as the previous frame and sets the next frame as the current frame. The flow further returns to step S510 for the backlight control method 500.

In step S570, the display control circuit 110 determines whether the next frame starts when the actual frame display time of the current frame does not reach the frame refresh time length.

In step S580, when the actual frame display time does not reach the frame refresh time length and the next frame starts, the display control circuit 110 controls the backlight module 130 to output the constant-brightness backlight with the compensation brightness after reaching the frame refresh time length to maintain the preset brightness until the next frame starts.

In step S585, the display control circuit 110 sets the next frame as the previous frame and sets the next frame as the current frame. The flow further returns to step S510 for the backlight control method 500.

When it is determined in step S570 that the actual frame display time of the current frame has not reached the frame refresh time length and the next frame has not yet started, the process returns to step S530 for determination.

It should be noted that the above-mentioned embodiment is only an example. In other embodiments, modifications and variations can be made by one skilled in the art without departing from the spirit of the invention. In addition, the above method steps can be implemented by hardware, software or firmware according to the requirement of a designer.

In summary, the display control circuit with dynamic backlight adjustment mechanism and the backlight control method thereof in the present invention can maintain the same average brightness by the dynamic backlight adjustment mechanism when the refresh frequency of the frame of the backlight module changes, thereby realizing the stroboscopic backlight.

Although the embodiments of the present invention have been described above, these embodiments are not intended to limit the present invention, and those skilled in the art can apply variations to the technical features of the present invention according to the contents explicitly or implicitly included in the present invention, which may fall into the scope of patent protection sought by the present invention, in other words, the scope of patent protection sought by the present invention should be subject to the claims of the present invention.

Description of reference numerals:

100: display device

110: display control circuit

120: display panel

130: backlight module

300: actual output waveform

500: backlight control method

S510 to S585: step (ii) of

AB: compensating for brightness

BI1 to BI5: backlight time starting point

BL1 to BL5: length of time of opening

BS: backlight control signal

DB: preset brightness

FD: frame

FR1 to FR5: frame

HS: image source

IL1 to IL5: length of start time

IS: image signal

IN1: first interval

IN2: second interval

RL1 to RL5: length of frame refresh time

TB1 to TB5: backlight on time

TI1 to TI5: starting point of refresh time

TP1 to TP5: frame refresh time

Claims

1. A backlight control method with dynamic backlight adjustment mechanism is applied to a display control circuit, the display control circuit is configured to receive an image signal from an image source and accordingly generate a plurality of frames to a display panel for displaying and generate a backlight control signal to a backlight module for switching operation, the backlight control method comprises the following steps:

obtaining, by the display control circuit, a frame refresh time length of a previous frame;

when a current frame starts, the display control circuit controls the backlight module to output a stroboscopic backlight with a preset brightness within a backlight starting time;

judging whether the actual picture display time of the current frame reaches the frame refreshing time length and whether a next frame starts or not by the display control circuit;

when the actual picture display time reaches the frame refreshing time length and the next frame is not started, the display control circuit controls the backlight module to output a constant-brightness backlight with a compensation brightness so as to maintain the preset brightness until the next frame is started; and

and when the actual picture display time does not reach the frame refreshing time length and the next frame starts, the display control circuit controls the backlight module to output the constant-brightness backlight with the compensation brightness after reaching the frame refreshing time length so as to maintain the preset brightness until the next frame starts.

2. The backlight control method according to claim 1, wherein a plurality of time parameters of the backlight turn-on time are set according to the frame refresh time length and a plurality of preset time ratio parameters, the plurality of time parameters including a start time length and a turn-on time length, the plurality of preset time ratio parameters including a start time ratio and a turn-on time ratio;

the starting time proportion determines the proportion between the starting time length of a backlight time starting point of the backlight starting time relative to a refreshing time starting point of a frame refreshing time and the frame refreshing time length; and

the on-time ratio determines a ratio between the on-time length of the backlight on-time and the frame refresh time length.

3. The backlight control method according to claim 1, further comprising:

accumulating, by the display control circuit, a horizontal synchronization signal of the previous frame to obtain the frame refresh time length.

4. The backlight control method according to claim 1, further comprising:

and the display control circuit captures refresh frequency information from the image signal to obtain the frame refresh time length.

5. The backlight control method according to claim 1, further comprising:

and when the actual picture display time reaches the frame refreshing time length and the next frame starts, the display control circuit does not perform compensation.

6. The backlight control method according to claim 1, further comprising:

and when the display control circuit controls the backlight module to output the constant-brightness backlight with the compensation brightness, the constant-brightness backlight is output according to a pulse width modulation waveform, and the pulse width modulation waveform has a working period same as that of the stroboscopic backlight.

7. The backlight control method of claim 1, wherein the magnitude of the compensation brightness is equal to a magnitude of an average brightness of the stroboscopic backlight in the frame refresh time length.

8. The backlight control method according to claim 1, further comprising:

and the display control circuit judges whether the next frame starts or not according to whether a vertical synchronous signal is received or not.

9. The backlight control method according to claim 1, further comprising:

setting, by the display control circuit, the current frame as the previous frame and the next frame as the current frame when the actual picture display time reaches the frame refresh time length and the next frame is started;

setting the current frame as the previous frame and setting the next frame as the current frame by the display control circuit when controlling the backlight module to output the constant-brightness backlight until the next frame starts; and

and when the display control circuit controls the backlight module to output the constant-brightness backlight until the next frame starts, setting the next frame as the previous frame and setting the next frame as the current frame.

10. A display control circuit with a dynamic backlight adjustment mechanism is electrically coupled to a display panel and a backlight module, and is configured to:

receiving an image signal from an image source, generating a plurality of frames to the display panel for displaying and generating a backlight control signal to the backlight module for switching;

obtaining a frame refresh time length of a previous frame;

when a current frame starts, controlling the backlight module to output a stroboscopic backlight with a preset brightness within a backlight starting time;

judging whether the actual picture display time of the current frame reaches the frame refreshing time length or not and whether a next frame starts or not;

when the actual picture display time reaches the frame refreshing time length and the next frame is not started yet, controlling the backlight module to output a constant-brightness backlight with a compensation brightness to maintain the preset brightness until the next frame is started; and

and when the actual picture display time does not reach the frame refreshing time length and the next frame starts, controlling the backlight module to output the constant-brightness backlight with the compensation brightness after reaching the frame refreshing time length so as to maintain the preset brightness until the next frame starts.