KR20100029863A - Video display apparatus and method for video display the same - Google Patents

Abstract

PURPOSE: A video display device and a video display method thereof are provided to solve a problem that the brightness level for interpolation video cannot be set by executing a backlight setting based on an input video. CONSTITUTION: A video display device and a video display method thereof includes a video signal input unit, a virtual frame making unit, a luminance information acquisition unit, and a backlight setting unit. The video signal input unit receives a video signal to be displayed through a display panel. The virtual frame making unit generates a virtual frame inserted based on the amount of the movement change between frames of a video signal. The luminance information acquisition unit gets luminance information of all input frames including the virtual frame. The backlight setting unit sets a contrast level based on frame luminance information.

Description

Video Display Apparatus and method for Video Display the same}

The present invention relates to an image display device, and more particularly, to an image display and an image display method for setting the brightness of a backlight of a display module according to a 120 Hz output image made by a frame rate converter (FRC).

Recently, as the technology of the video display device is developed, the method of displaying the broadcast signal is also developed, and accordingly, a 120Hz drive video display device has been developed and marketed recently. .

This is the way that the video display device shows 60 pictures per second, that is, 60 pictures per second. By inserting another new frame between the frames and frames, 120 pictures per second are displayed.

As a result, the visual response speed 'MPRT' (Moving Picture Response Time) is improved in a fast screen image such as sports, which causes less phenomenon such as motion blur.

Here, a method of converting the 60 frames into 120 frames includes a doubling method and a new frame generation method.

The doubling method is a method of repeatedly displaying the same frame twice and converting the same frame and each frame into 120 frames. The method of generating the new frame analyzes the operation between the frame and the frame. To create a new intermediate frame through some kind of screen interpolation.

In the case of still images, there is no change in motion, so even if you configure 120 frames using the doubling method, there is no problem in watching the screen. As a result, an image may appear broken.

Therefore, as a method of implementing the 120Hz, a method of generating a new frame is generally used. As a result, it is possible to expect an effect of increasing the response speed by dividing the time finely. Can be designed.

That is, the method of generating the new frame is implemented by an algorithm called so-called 'intermediate image prediction interpolation', which is a high-level computational chip for changing the position of the intermediate value between each frame among the 60 frames shown in the 60 Hz signal. Interpolation method that embeds a new frame predicted by. For example, 1/2/3/4... ... Between screen integers 1 / 1.5 / 2 / 2.5... Put an intermediate value like this.

In other words, conventionally, motion prediction is performed by comparing a current frame and a previous frame, thereby generating a virtual frame to be inserted between the current frame and the previous frame.

However, in the above-described 120Hz implementation method, a problem arises in that the setting of the backlight does not coincide with the newly generated virtual frames.

That is, in the conventional 120Hz implementation method, the brightness level of the backlight is set based on the first 60Hz or 50Hz image input, and the 120Hz image is output according to the backlight brightness level set based on the 60Hz or 50Hz.

Therefore, as shown in FIG. 1, the brightness level of the backlight is adjusted only for A, B, C, and D, which are original input images, and is not adjusted for A, B, and C, which are newly generated virtual frames. There is this.

That is, the brightness level of the backlight should be adjusted based on the luminance information of the newly generated virtual frames A`, B`, and C`, but the brightness is based on the luminance information of the previous images A, B, and C`. There is a problem that the brightness level of the backlight is adjusted when outputting A, B, and C images.

According to an embodiment of the present invention, it is possible to solve the problem that the backlight brightness setting of the display module by the main process does not coincide with the newly generated virtual frames.

In addition, according to an embodiment of the present invention, the luminance information of the image output from the frame rate converter (FRC) that produces the actual output image may be measured, and the backlight setting may be adjusted based on the measured luminance information.

In addition, according to an embodiment of the present invention, the image adjustment processing depending on the input image can be set correctly based on the image actually output.

An image display according to an embodiment of the present invention comprises a display panel; An image signal input unit for receiving an image signal to be displayed through the display panel; A virtual frame generation unit generating a virtual frame to be inserted into a current frame and a previous frame based on the amount of change in the inter-frame motion of the video signal inputted through the video signal input unit; A luminance information obtaining unit obtaining luminance information of all input frames including the virtual frame generated by the virtual frame generating unit; And a backlight setting unit that sets the brightness level of the backlight based on the luminance information for each frame obtained through the luminance information obtaining unit.

In addition, the video display method of the video display device according to an embodiment of the present invention comprises the steps of inputting a video signal; Generating and outputting a virtual frame to be inserted into a current frame and a previous frame according to the interframe motion variation of the input video signal; Acquiring luminance information of all input frames including the generated virtual frame; And setting the brightness level of the backlight based on the obtained brightness information.

The image display device and the image display method according to an embodiment of the present invention can solve the problem that the brightness level of the backlight cannot be set correctly for the interpolated images by setting the backlight depending on the input image, and also output the image. By setting the brightness level of the backlight correctly, the user satisfaction can be improved.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the spirit of the present invention is not limited to the embodiments presented, and other embodiments included within the scope of other inventive inventions or the scope of the present invention can be easily made by adding, changing, or deleting other elements. I can suggest.

The term used in the present invention was selected as a general term widely used now, but in some cases, the term is arbitrarily selected by the applicant, and in this case, the meaning of the term is described in detail in the description of the present invention. It should be clear that the present invention is to be understood as a meaning of terms.

2 is a block diagram illustrating a configuration of an image display device according to an exemplary embodiment of the present invention, FIG. 3 is a diagram illustrating a change in brightness of an output image according to a change in backlight brightness level, and FIG. 4 is according to an exemplary embodiment of the present invention. FIG. 5 is a diagram illustrating a virtual frame generation of an image display device. FIG. 5 is a diagram illustrating a backlight setting timing for an output image according to an embodiment of the present invention. FIG. 6 is a view illustrating an image display device according to an embodiment of the present invention. FIG. 7 is a flowchart for explaining an image display method step by step. FIG. 7 is a flowchart for explaining step by step an image display method of an image display device according to a second embodiment of the present invention.

As shown in FIG. 2, the image display device according to an exemplary embodiment of the present invention displays a backlight 10, a backlight driver 20 supplying a driving voltage corresponding to the brightness level of the backlight 10, and an image. The display panel 30, the video signal input unit 40 for receiving an image signal to be displayed through the display panel 30, and an interframe motion change amount of the video signal input through the video signal input unit 40. A virtual frame generator 50 for generating a virtual frame to be inserted into a current frame and a previous frame based on the second frame; and luminance information for acquiring luminance information for each frame of an image signal output through the virtual frame generator 50; A unit 60, a synchronous signal output unit 70 for generating and outputting a synchronous signal for notifying the start of each frame output to the display panel 30, and a back light according to the luminance information of the video signal. A memory unit 80 storing a light brightness level value and a backlight setting unit 90 configured to set the brightness level of the backlight 10 based on the frame-specific brightness information obtained through the brightness information acquisition unit 60. It is configured by.

Referring to the operation of the video display device according to an embodiment of the present invention configured as described above are as follows.

The backlight 10 is disposed at the rear of the display panel 30 to supply light to the front of the display panel 30.

The backlight driver 20 supplies a driving voltage for driving the backlight 10 based on a preset backlight brightness level.

That is, the screen brightness of the display panel 30 is controlled by supplying a driving voltage to the backlight 10 through the backlight driver 20, which is configured to supply a driving voltage according to a preset screen brightness condition to the backlight driver ( 20 is supplied to the backlight 10 by changing the current according to the supplied driving voltage.

In other words, the backlight driver 20 changes the driving voltage according to the backlight brightness level value set through the backlight setting unit 90 to be described later, and adjusts the current flowing toward the backlight 10 by the changed driving voltage. do.

The current flowing toward the backlight 10 is changed according to the driving voltage supplied through the backlight driver 20. That is, the magnitude of the current flowing through the backlight 10 is changed in proportion to the magnitude of the driving voltage supplied through the backlight driver 20.

Accordingly, by adjusting the current flowing toward the backlight 10, the DC level of the original input signal is maintained as it is, and the brightness of the display panel 30 is adjusted to output the input image at a brightness desired by the user without losing the original image. You can do it.

In other words, by adjusting the brightness level of the backlight 10, as shown in Figure 2, the 0 ~ 255 level of the original signal is all live, so that the resolution of the signal is reduced by adjusting the brightness of the output image without damaging the signal. In addition to preventing this, the DC level of the signal is still alive, which effectively controls contrast.

The display panel 30 is a means for displaying an input image, which is preferably a liquid crystal display (LCD) panel.

The image signal input unit 40 is a means for receiving an image to be displayed on the display panel 30 and may include a tuner for tuning a broadcast signal of a specific channel selected by a user, and corresponds to various external sources. The video signal may include an AV terminal, an S-video terminal, a COMPONENT terminal, a PC-signal terminal, and the like.

The virtual frame generator 50 generates a virtual frame for converting a 50 Hz / 60 Hz image input through the image signal input unit 40 into a 100 Hz / 120 Hz image.

That is, the virtual frame generation unit 50 divides the current frame of the video signal output through the video signal input unit 40 into a plurality of blocks having a predetermined size, and thus provides a current for motion estimation of the plurality of blocks. A motion estimation unit (not shown) for comparing a block and a predetermined search area set in a previous frame and measuring a motion change amount between frames, and between the current frame and the previous frame according to the motion change amount between frames calculated by the motion estimation unit. It includes a motion compensation unit (not shown) for generating a virtual frame to be located in.

In other words, the virtual frame generation unit 50 compares the motion difference between the previous frame (Frame 1) 100 and the current frame (Frame 3) 110 as shown in FIG. 4, and compares the motion difference. By performing the motion prediction according to the result, a new frame (Frame 2) 120 is generated and inserted according to the change of the position of the intermediate value between the frame 1 (100) and the frame 3 (110).

Similarly, the motion difference between the frame 3 110 and the frame 5 130 is compared, and the motion prediction according to the motion difference is performed to change the position of the intermediate value between the frame 3 110 and the frame 5 130. Create a new frame (frame 4) 140 accordingly.

As described above, the process is repeatedly performed to convert an image of 50/60 frames into an image of 100/120 frames.

The luminance information acquisition unit 60 obtains frame-by-frame luminance information output through the virtual frame generation unit 50.

In this case, the luminance information obtaining unit 60 obtains luminance information on all frames including the frame of the image input through the image signal input unit 40 and the virtual frame generated by the virtual frame generating unit 50. do.

In this case, the luminance information may be an average luminance level (APL) of each image signal of the image signal output through the virtual frame generator 50.

In this case, in the first embodiment of the present invention, the luminance information obtaining unit 60 obtains only the corresponding luminance information for each of the frames, but in the second embodiment of the present invention, the luminance information obtaining unit 60 is a preset backlight. The average brightness information of the frame group including a specific number of frames is obtained according to the brightness setting condition.

That is, if the brightness level of the backlight is changed based on the brightness information of each frame, the quality of the output image may be affected by frequent brightness changes of the backlight.

Therefore, in the second embodiment of the present invention, a predetermined number of frames are set to one frame group according to the backlight brightness setting condition set by the user, and the corresponding frame group is made using the luminance levels of all the frames belonging to the set frame group. Obtain average luminance information corresponding to.

Here, the backlight brightness setting condition means the number of frames to be grouped into one frame group.

Backlight brightness setting condition Number of frames One 2 2 4 3 6 4 8 5 10

That is, as shown in Table 1, the brightness information acquisition unit 60 in the second embodiment according to the present invention checks the preset backlight brightness setting condition and specifies according to the number of frames corresponding to the checked backlight brightness setting condition. After the number of frames is designated as one frame group, average luminance information according to the frame group is obtained according to the luminance information of the frames belonging to the designated frame group.

The synchronization signal output unit 70 generates and outputs a synchronization signal indicating the start of output of each frame output to the display panel 30 through the virtual frame generation unit 50.

That is, in general, a predetermined number of output frames are delayed to generate a virtual frame to be inserted into a current frame and a previous frame through the virtual frame generator 60.

Therefore, a gap of a predetermined number of frames occurs between the frame output through the display panel 30 and the frame input through the image signal input unit 40, and accordingly, the display panel 30 is actually present. The information of the output frame cannot be confirmed.

Accordingly, when the frame to be currently displayed is transmitted to the display panel 30 through the virtual frame generation unit 60, the synchronization signal output unit 70 notifies the start of output of the transmitted frame, A synchronizing signal for generating information about whether a frame is output is generated and output.

In this case, the synchronization signal output unit 70 in the first embodiment of the present invention generates and outputs the synchronization signal in units of frames. However, the synchronization signal output unit 70 in the second embodiment is configured in units of frame groups. Generate and output a sync signal.

That is, when six frames are currently set to one frame group, a synchronization signal is generated and output in units of six frame groups.

The memory unit 80 stores a backlight brightness value corresponding to the luminance information of the frame or the average luminance information of a frame group including a predetermined number of frames. The backlight brightness value is preferably a dimming level of the backlight 10.

The backlight setting unit 90 changes the brightness of the backlight 10 according to the brightness information or the average brightness information obtained through the brightness information obtaining unit 60.

That is, an interrupt is generated by the sync signal output through the sync signal output unit 70, and the backlight setting unit 90 is configured to generate a frame or a group of frames currently output through the display module due to the generated interrupt. The corresponding luminance information or the average luminance information is read, and the brightness of the backlight 10 is changed based on the read luminance information or the average luminance information.

In other words, the backlight setting unit 90 uses a method of continuously monitoring the synchronization signal output every frame through the virtual frame generation unit 50 or the synchronization output through the synchronization signal output unit 70. By connecting a signal to the interrupt source of the backlight setting unit 90, a backlight brightness setting method may be used.

In this case, in order to set the brightness of the backlight in the first method, since the backlight setting unit 90 needs to check whether the corresponding synchronization signal is input at high speed, the load of the backlight setting unit 90 increases and the period of checking Error occurs.

Therefore, in the embodiment of the present invention, the brightness of the backlight is set by the second method.

That is, when the interrupt method is used, an interrupt is internally generated whenever the synchronization signal is input from the backlight setting unit 90, and the brightness of the backlight is calculated and set by a function for processing the generated interrupt. .

In other words, whenever an image is output through the virtual frame generation unit 50, a synchronization signal is output, and an internal interrupt is generated in the backlight setting unit 90 by the signal, and the interrupt is generated by the generated interrupt. By setting the brightness level of the backlight, you can synchronize the brightness setting of the backlight to match the currently displayed image.

In addition, the backlight setting unit 90 may calculate and set a backlight brightness value corresponding to the brightness information or the average brightness information by using a predefined function, or the brightness information or the average information stored in the memory unit 90. It can also be set using a star backlight brightness table.

That is, the backlight setting unit 90 in the first embodiment of the present invention reads luminance information according to the currently output frame and sets the backlight brightness level corresponding thereto according to the read luminance information. In other words, the backlight setting unit 90 sets the backlight brightness according to the frame unit and changes the brightness of the backlight frame by frame.

In addition, the backlight setting unit 90 according to the second exemplary embodiment of the present invention reads average luminance information of a frame group to which a currently output frame belongs, and sets a corresponding backlight brightness level according to the read average luminance information. do. In other words, the backlight setting unit 90 sets the backlight brightness level on a frame group basis. Accordingly, when all the frames belonging to one frame group unit are output, the backlight is driven at the same brightness according to the average brightness information thereof. do.

That is, as shown in FIG. 5, an initially input image is a 50/60 frame image, which is converted into a 100/120 frame image through the virtual frame generator 50 and output. In this case, the brightness information acquisition unit 60 obtains brightness information on the converted and output frame, and the synchronization signal output unit 70 passes through the virtual frame generation unit 50 to the display panel 30. The synchronous signal for notifying the start of frame output is generated and output.

Then, an interrupt is generated according to the output synchronization signal, and the backlight setting unit 90 sets the backlight brightness level according to the luminance information corresponding to the currently output frame according to the generated interrupt. .

As described above, the image display device according to the embodiment of the present invention can solve the problem of not being able to set the correct brightness level of the backlight for the interpolated images by setting the backlight depending on the input image. By setting the brightness level of the backlight correctly as a reference, user satisfaction can be improved.

In the image display method of the image display device according to the first embodiment of the present invention configured as described above, as shown in FIG. 6, an image signal to be displayed is first received through the display panel 30 (S10).

Subsequently, a virtual frame to be inserted into the current frame and the previous frame is generated based on the amount of change in interframe motion of the input video signal (S20). That is, by dividing the current frame of the input video signal into a plurality of blocks of a predetermined size, the amount of motion change between frames by comparing the current block for motion estimation with a predetermined search area set in a previous frame. The virtual frame is to be located between the current frame and the previous frame according to the calculated movement change amount between the frames.

In operation S30, luminance information of all frames including the generated virtual frame is obtained. That is, the frame-by-frame luminance information of the image signal having the changed frame rate is obtained by generating a virtual frame.

Subsequently, a synchronization signal for notifying a frame output to the current display panel 30 is generated and generated (S40).

In operation S50, luminance information corresponding to a frame currently output through the display panel 30 is read according to the generated synchronization signal. That is, a synchronization signal is output every time the image is output, and the luminance information of the currently displayed frame is read by an internal interrupt generated by the output synchronization signal.

Subsequently, the brightness value of the backlight is set based on the read luminance information (S60).

The brightness of the preset backlight is changed based on the set backlight brightness value (S70).

In addition, in the image display method of the image display device according to the second embodiment of the present invention, as shown in FIG. 7, first, an image signal to be displayed is received through the display panel 30 (S100).

Subsequently, a virtual frame to be inserted into the current frame and the previous frame is generated based on the amount of change in interframe motion of the input video signal (S110). That is, by dividing the current frame of the input video signal into a plurality of blocks of a predetermined size, the amount of motion change between frames by comparing the current block for motion estimation with a predetermined search area set in a previous frame. The virtual frame is to be located between the current frame and the previous frame according to the calculated movement change amount between the frames.

In operation S120, luminance information of all frames including the generated virtual frame is obtained. That is, the frame-by-frame luminance information of the image signal having the changed frame rate is obtained by generating a virtual frame.

Subsequently, the preset backlight brightness setting condition is determined (S130).

The predetermined number of frames is set to one frame group according to the identified backlight brightness setting condition, and average luminance information is obtained for each set frame group (S140).

Subsequently, a synchronization signal for notifying the output of the frame belonging to the new frame group is generated and output (S150). That is, in the first embodiment, the synchronization signal is generated and output whenever the currently displayed frame is changed. In the second embodiment, the synchronization signal is generated and output only when the frame group is changed. In other words, even if the frame currently displayed is changed, the synchronization signal is not generated if the frame belongs to the same frame group as the previously displayed frame.

In operation S160, the average luminance information corresponding to the frame group to which the currently output frame belongs is read according to the generated synchronization signal.

Subsequently, a backlight brightness value is set based on the read average brightness information (S170).

In operation S180, the brightness of the preset backlight is changed based on the set backlight brightness value.

Accordingly, in the second embodiment of the present invention, a predetermined number of frames are set as one frame group without changing the brightness of the backlight every frame, and the brightness of the backlight is changed for each set frame group.

As described above, the image display device and the image display method according to the embodiment of the present invention can solve the problem that the brightness level of the backlight cannot be set correctly for the interpolated images because the backlight setting is made depending on the input image. The user's satisfaction can be improved by setting the brightness level of the backlight correctly based on the displayed image.

1 is a view showing a backlight setting timing according to the prior art.

2 is a block diagram illustrating a configuration of an image display device according to an exemplary embodiment of the present invention.

3 is a view showing a change in brightness of the output image according to the change of the backlight brightness level.

4 is a view for explaining virtual frame generation of an image display device according to an embodiment of the present invention;

5 is a diagram illustrating backlight setting timing of an output image according to an exemplary embodiment of the present invention.

6 is a flowchart for explaining a method of displaying an image of a video display device according to a first embodiment of the present invention step by step;

7 is a flowchart for explaining step by step an image display method of an image display device according to a second embodiment of the present invention;

<< Explanation of symbols for main part of drawing >>

10: backlight 20: backlight driver

30: display panel 40: video signal input unit

50: virtual frame generation unit 60: luminance information acquisition unit

70: synchronization signal output section 80: memory section

90: backlight setting section

Claims (11)

Display panel; An image signal input unit for receiving an image signal to be displayed through the display panel; A virtual frame generation unit generating a virtual frame to be inserted into a current frame and a previous frame based on the amount of change in the inter-frame motion of the video signal inputted through the video signal input unit; A luminance information obtaining unit obtaining luminance information of all input frames including the virtual frame generated by the virtual frame generating unit; And, And a backlight setting unit configured to set the brightness level of the backlight based on the luminance information for each frame obtained by the luminance information obtaining unit. The method of claim 1, And the luminance information obtaining unit obtains average luminance information of a frame group consisting of a specific number of frames according to a preset backlight brightness setting condition. The method of claim 1, And a memory unit configured to store a backlight brightness level value according to the brightness information of the video signal. The method of claim 1, And a synchronizing signal output unit configured to generate and output a synchronizing signal for notifying the start of each frame output to the display panel. The method of claim 4, wherein And the backlight setting unit sets the brightness level of the backlight with reference to the luminance information of the frame currently displayed on the display panel based on the interrupt generated according to the output of the synchronization signal. Inputting a video signal; Generating and outputting a virtual frame to be inserted into a current frame and a previous frame according to the interframe motion variation of the input video signal; Acquiring luminance information of all input frames including the generated virtual frame; And, And setting the brightness level of the backlight based on the obtained brightness information. The method of claim 6, Acquiring luminance information of all the input frames Obtaining luminance information of all input frames including the virtual frame; And obtaining average luminance information of a frame group consisting of a specific number of frames according to a preset backlight brightness setting condition. The method of claim 6, And generating and outputting a synchronous signal for notifying the start of output of each frame to the display panel. The method of claim 8, Setting the brightness level of the backlight based on the obtained brightness information Reading luminance information of a frame currently output to a display panel in response to the output synchronization signal; And setting the brightness level of the backlight based on the read luminance information. The method of claim 8, The generating and outputting the synchronization signal may include And generating and outputting a synchronization signal corresponding to each frame group including a specific number of frames. The method of claim 10, Setting the brightness level of the backlight based on the obtained brightness information Reading average luminance information of a frame group corresponding to the interrupt generated by the output of the synchronization signal; And setting the same backlight brightness level of the frames belonging to the frame group based on the read average brightness information.

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