KR102276652B1 - Display Device and Driving Method Thereof - Google Patents

Abstract

The display device according to an embodiment of the present invention divides the data of the current frame input from the outside into k (k is a natural number) bit first data corresponding to the horizontal line of the panel, and divides the first data by i (i is a timing control unit including a first calculating unit for converting the second data of bits (a natural number less than k); a memory for storing second data of a previous frame; The timing controller compares the second data of the current frame with the second data of the previous frame to determine whether the image displayed on the panel is a still image or a moving image.

Description

Display Device and Driving Method Thereof

The present invention relates to a display device and a driving method thereof.

With the development of information technology, the importance of a display device, which is a connection medium between a user and information, has been highlighted. Accordingly, the use of display devices such as organic light emitting displays and liquid crystal displays is increasing.

Such a display device detects an image of the display panel and controls the image of the display panel in various ways in response to the detected result. For example, the display device may change data corresponding to the type of image (still image, moving image, etc.) displayed on the display panel.

Here, the display device uses two frame memories to sense the image of the display panel. For example, by storing data of the current frame in the first frame memory and data of the previous frame in the second frame memory, and comparing the data of the first frame memory and the second frame memory, the image displayed on the display panel is displayed as a still image or Decide if it's a video.

However, when two frame memories are built in the data driver, there is a disadvantage in that the mounting area is nearly doubled. In addition, when data is compressed and restored in order not to add a frame memory, there is a disadvantage in that power consumption increases by 30% to 50% due to a complicated algorithm.

The present invention for solving the problems of the above-mentioned background art is to determine a still image or a moving image without a full frame memory.

The display device according to an embodiment of the present invention divides data of a current frame input from the outside into k (k is a natural number) bit first data corresponding to a horizontal line of a panel, and divides the first data into i (i is a timing control unit including a first calculating unit for converting the second data of bits (a natural number less than k); a memory for storing second data of a previous frame; The timing controller compares the second data of the current frame with the second data of the previous frame to determine whether the image displayed on the panel is a still image or a moving image.

The timing controller generates the second data using a cyclic redundancy check (CRC) method.

The timing control unit compares the second data of the current frame with the second data of the previous frame in units of horizontal lines, and a pixel change rate according to the second data of the current frame and the second data of the previous frame is set in advance. When the threshold value of 1 is exceeded, it is determined that the second data of the current frame is changed in the corresponding horizontal line.

The timing controller determines that the moving image is displayed on the panel in which the rate of change of second data in the current frame exceeds a preset second threshold, otherwise it is determined that the still image is displayed on the panel do.

The timing controller includes a second calculator that extracts luminance information in units of pixels from the data of the current frame, and averages the luminance information in units of pixels to generate third data including average grayscale information of the current frame. .

The timing controller is configured to display the still image without changing the luminance of the panel for a predetermined period of time, and when the luminance of the panel exceeds a preset threshold luminance, and the average gradation information of the third data exceeds a preset threshold gradation, the Lower the luminance of the panel.

A method of driving a display device according to an embodiment of the present invention includes converting k (k is a natural number) bit first data corresponding to a horizontal line of a panel into i (i is a natural number less than k) bit second data. and comparing the second data of the current frame with the second data of the previous frame to determine whether the image displayed on the panel is a still image or a moving image.

The second data is generated by a CRC (Cyclic Redundancy Check) method.

When the pixel change rate by the second data of the current frame and the second data of the previous frame in units of horizontal lines exceeds a preset first threshold, it is determined that the second data of the current frame is changed in the corresponding horizontal line.

When the rate of change of the second data in the current frame exceeds a preset second threshold, it is determined that the moving image is displayed on the panel, and in other cases, it is determined that the still image is displayed on the panel. .

The method further includes extracting luminance information in units of pixels from the data of the current frame and averaging the luminance information in units of pixels to extract an average grayscale of the current frame.

When the still image is displayed for a predetermined time without changing the luminance of the panel, the luminance of the panel exceeds a preset threshold luminance, and the average gradation of the current frame exceeds a preset threshold luminance, the luminance of the panel is lowered.

According to a display device and a driving method thereof according to an embodiment of the present invention, first data for one horizontal line is converted into second data using a cyclic redundancy check (CRC) method. In addition, the type of image displayed on the panel may be determined by comparing the second data of the previous frame and the current frame. Here, the second data generated using the CRC method is set to a bit lower than the first data (eg, 16 bits), and accordingly, the full frame memory may be deleted.

In addition, according to the present invention, there is no need to compress and restore data in order to determine an image displayed on the display panel, and thus power consumption can be minimized. Additionally, in the present invention, when a still image is displayed for a predetermined time or longer, the non-restored afterimage may be alleviated by lowering the luminance of the display panel.

1 is a schematic configuration diagram of a display device according to an embodiment of the present invention.
2 is a diagram illustrating a timing controller according to an embodiment of the present invention.
3 is a diagram illustrating an operation process of a first calculator.
4 is a diagram illustrating a method for determining a moving image and a still image according to an embodiment of the present invention.
5 is a diagram illustrating an error rate corresponding to a CRC method.
6 is a flowchart illustrating a method of driving a timing controller according to an embodiment of the present invention.
7A and 7B are diagrams illustrating luminance and grayscale.
8 is a diagram illustrating an embodiment of a change in luminance of a display panel.
FIG. 9 is a diagram illustrating an embodiment of the sub-pixel shown in FIG. 1 .

Hereinafter, preferred embodiments in which a person of ordinary skill in the art to which the present invention pertains can easily practice the present invention will be described in detail with reference to the accompanying FIGS.

1 is a schematic configuration diagram of a display device according to an embodiment of the present invention.

Referring to FIG. 1 , a display device according to an embodiment of the present invention includes a timing controller 130 (T-CON), a memory 140, Memory, a data driver 150 (SD-IC), and a scan driver 160 and GD- IC) and a display panel 170 (PANEL).

The memory 140 stores the second data Data2 supplied from the timing controller 130 . Here, the second data Data2 includes image information of each horizontal line of the display panel 170 . The memory 140 for storing the second data Data2 has a lower storage capacity than the full-frame memory 140 for storing data of one frame.

The timing controller 130 receives a driving signal such as a data enable signal, a vertical synchronization signal, a horizontal synchronization signal and a clock signal and data for implementing an image from an external host.

The timing controller 130 includes a gate timing control signal GDC for controlling an operation timing of the scan driver 160 and a data timing control signal DDC for controlling an operation timing of the data driver 150 based on the driving signal. to output

In addition, the timing controller 130 converts data (Data) for one frame input from the outside to first data (Data1) corresponding to each horizontal line of the display panel 170 as shown in FIGS. 2 and 3 . separate

Here, the first data Data1 is set to k (k is a natural number) bits, and its size is determined in correspondence with the inch and resolution of the panel. For example, when the number of pixels included in each horizontal line is 312 and data bits are 8 bits, k may be set to 7488 bits by 312 × 3 (R, G, B) × 8.

The timing controller 130 receiving the k-bit first data Data1 generates second data Data2 by using the first data Data1 to include the image information of the horizontal line. Here, the second data Data2 is set to i (i is a natural number) bits smaller than k bits. The timing controller 130 that has generated the second data Data2 of the current frame compares the second data Data2 of the previous frame stored in the memory 140 with the second data Data2 of the current frame on the display panel The type of the image displayed at 170 is determined.

For example, the timing controller 130 compares the second data Data2 of the current frame with the second data Data2 of the previous frame for each horizontal line, and compares the second data Data2 of the current frame with the second data Data2 of the previous frame. An image displayed on the display panel 170 may be determined as a moving image or a still image in response to a change rate of the second data Data2 . The second data Data2 generated by the timing controller 130 is stored in the memory 140 .

Also, the timing controller 130 generates third data Data3 including average grayscale information by using data corresponding to one frame. The third data Data3 includes Average Peak Luminance (APL) information of one frame. Such third data Data3 is calculated by real-time operation and is not separately stored in the memory 140 .

The data driver 150 receives the data timing control signal DDC and the data Data from the timing controller 130 . The data driver 150 receiving the data timing control signal DDC converts the data into an analog data signal using a gamma voltage. At this time, the data signal is generated to have a predetermined voltage corresponding to the bit value (ie, gray level) of the data. The data driver 150 that generates the data signal supplies the data signal to the data lines DL1 to DLm to be synchronized with the scan signal.

The scan driver 160 outputs a scan signal while shifting the level of the gate voltage in response to the gate timing control signal GDC supplied from the timing controller 130 . For example, the scan driver 160 may sequentially supply a scan signal to the scan lines SL1 to SLn. When a scan signal is supplied from the scan driver 160 to the scan lines SL1 to SLn, the sub-pixels SP located on the corresponding horizontal lines are selected. The sub-pixel SP selected by the scan signal stores the voltage of the data signal and emits light in response to the stored data signal. The scan driver 160 is formed in the form of an integrated circuit or in the form of a gate in panel on the display panel 170 .

Sub-pixels SP are formed in the display panel 170 . Here, the display panel 170 may be implemented as a liquid crystal display device, an organic light emitting display device, an electrophoretic display device, or the like. The sub-pixels SP store a data signal when a scan pulse is supplied, and emit light of a predetermined gradation in response to the stored data signal.

2 is a diagram illustrating a timing controller according to an embodiment of the present invention.

Referring to FIG. 2 , the timing controller 130 according to the embodiment of the present invention includes a first calculator 132 and a second calculator 134 .

The timing controller 130 divides data input from the outside into first data Data1 corresponding to a horizontal line of the display panel 170 and supplies it to the first calculator 132 . The first calculator 132 generates i-bit second data Data2 by using the k-bit first data Data1.

Here, the first calculator 132 generates the second data Data2 by changing the first data Data1 using a cyclic redundancy check (CRC) method. As the CRC method used in the first calculation unit 132 , various currently known methods may be used.

For example, the first calculator 132 may generate the second data Data2 using a ^{CRC 16 (X 16} + X ¹² + X ⁵ + X ^{0 ) method.} In this case, the second data Data2 includes horizontal line information and is set to 16 bits. In fact, the first calculator 132 may use various types of CRC schemes so that information of each horizontal line can be stably included.

The second calculator 134 generates third data Data3 including average grayscale information by using data for one frame. Briefly describing the operation process, the second calculator 134 extracts luminance information in units of pixels. For example, the second calculator 134 may extract luminance information in units of pixels using a formula of Y=0.2R+0.7G+0.1B. The second calculator 134, which has extracted the luminance information in units of pixels, averages the luminance information for one frame to calculate average grayscale information of the frames. That is, the second calculator 134 generates the third data Data3 by averaging the luminance information of one frame. Here, the third data Data3 includes only average grayscale information for one frame and may be set to a low bit, for example, 8 bits.

3 is a diagram illustrating an operation process of a first calculator.

Referring to FIG. 3 , the first calculator 132 receives k-bit first data Data1 corresponding to a horizontal line.

The first calculator 132 receiving the first data Data1 generates i-bit second data Data2 using the CRC method. Here, if the CRC 16 method is used, the i bit is set to 16 bits. The second data Data2 generated by the first calculator 132 is stored in the memory 140 .

In the present invention, since the second data Data2 including information of each horizontal line, not the first data Data1 , is stored in the memory 140 , the size of the memory 140 can be minimized. In other words, since the second data Data2 for one frame is stored in the memory 140 of the present invention, and the second data Data2 is set to i bits, the size of the memory 140 can be minimized.

When the size of the memory 140 is minimized as described above, the size can be minimized when the timing controller 130 and the data driver 150 are implemented in the form of an integrated circuit (IC). (In the integrated circuit, the scan driver ( 160) may be additionally included.)

4 is a diagram illustrating a method for determining a moving image and a still image according to an embodiment of the present invention. In FIG. 4 , it is assumed that the current frame is j (j is a natural number) frame jF, and the previous frame is j-1 frame (j-1F) for convenience of explanation.

Referring to FIG. 4 , during the j frame period jF, the timing controller 130 generates second data Data2 using the first calculator 132 . The timing controller 130 generating the second data Data2 compares the second data Data2 of the j frame jF and the second data Data2 of the j-1 frame j-1F for each horizontal line. while determining the image of the display panel 170 as a moving image or a still image.

In more detail, when the CRC method is used, when the second data Data2 for each horizontal line is compared, the change rate of the pixel for each horizontal line can be known. Here, the second data Data2 of the j-1 frame j-1F and the second data Data2 of the j frame jF are compared, and the pixel change rate is set to be less than or equal to the first threshold value in response to the comparison result. In this case, the timing controller 130 determines that the second data Data2 of the corresponding horizontal line is not changed. Then, the second data Data2 of the j-1 frame j-1F and the second data Data2 of the j frame jF are compared, and the pixel change rate exceeds the first threshold value in response to the comparison result. In this case, the timing controller 130 determines that the second data Data2 of the corresponding horizontal line is changed.

Here, the first threshold value may be variously set according to the CRC method used. For example, when the CRC 8 method in which the second data Data2 is set to 8 bits is used, the first threshold value may be set to 15% in consideration of an error rate. In this case, if the pixel is changed by 15% or less in the horizontal line, it is determined that the second data Data2 of the corresponding horizontal line is the same, and in other cases, it is determined that the second data Data2 is changed.

In addition, when the CRC 16 method in which the second data (Data2) is set to 16 bits is used, the first threshold is set to 7% in consideration of the error rate, and the CRC 32 method in which the second data (Data2) is set to 32 bits is used. When used, the first threshold value may be set to 3% in consideration of the error rate.

Thereafter, the timing controller 130 comparing the second data Data2 for each horizontal line using the first threshold value determines whether the change rate of the second data Data2 exceeds the second threshold value based on the frame. .

For example, if the second data Data2 for one frame is changed to be less than or equal to the second threshold, the timing controller 130 determines that the image displayed in the j frame jF is a still image, and exceeds the second threshold. to be changed, the image displayed in the j frame (jF) is determined as a moving picture. Here, the second threshold value is set differently depending on the panel inch, resolution, and the like. For example, the second threshold may be set to 7%.

As described above, when the timing controller 130 determines an image using the first threshold value and the second threshold value, when the image of the display panel 170 is partially changed, it is recognized as a moving image and the luminance of the display panel 170 is changed. can be prevented from being changed.

5 is a diagram illustrating an error rate corresponding to a CRC method.

Referring to FIG. 5 , the second data Data2 may be set to 8-bit, 16-bit, 32-bit, 64-bit, etc. corresponding to the CRC method used. In this case, the larger the bit of the second data Data2, the lower the error rate.

Here, the error rate is set corresponding to the panel resolution, inches, and the bit size of the first data data1. Accordingly, in the present invention, the bits of the second data Data2 are experimentally determined to minimize the error rate.

As an example, the error rate is rapidly reduced up to a certain bit of the CRC, and is gently reduced when a certain bit is exceeded. In this case, a specific bit (16 bits in FIG. 5) may be set as a bit of the second data Data2.

Meanwhile, in the above description, a method for determining a moving image and a still image in the timing controller 130 has been described. Here, when a still image is displayed for a predetermined time or longer, an unreconstructed afterimage in which an afterimage of the image remains on the screen may be generated. Accordingly, in the present invention, when a still image is displayed for a predetermined time or longer, the luminance of the display panel 170 is controlled to minimize the non-restored afterimage.

6 is a flowchart illustrating a method of driving a timing controller according to an embodiment of the present invention. Referring to FIG. 6 , the method for improving the non-restored afterimage of the present invention is as follows.

<Determining the image displayed on the display panel: S200, S202>

The timing controller 130 receives data of the j frame jF from the outside. The timing controller 130 receiving the data of the j frame jF divides the data into first data Data1 corresponding to each horizontal line and supplies the data to the first calculator 132 .

The first calculator 132 generates i-bit second data Data2 by using the k-bit first data Data1. Thereafter, the timing controller 130 compares the second data Data2 of the j-1 frame j-1F stored in the frame memory 140 with the second data Data2 of the j frame jF. Here, the timing controller 130 determines whether the second data Data2 is changed in units of horizontal lines using the first threshold value. Then, the timing controller 130 determines whether the change rate of the second data Data2 exceeds a second threshold value. When the change rate of the second data Data2 in the j frame jF exceeds the second threshold value, the timing controller 130 determines that the image displayed on the display panel 170 is a moving image, and otherwise displays the image displayed on the display panel 170 . It is determined that the image displayed on the panel 170 is a still image.

When it is determined that the image displayed on the display panel 170 is a moving image, the timing controller 130 resets a counter value indicating a time for which a still image is displayed to an initial value (eg, “0”).

<Determination of change in luminance of display panel: S203, S202>

When it is determined that the image displayed on the display panel 170 is a still image in step S200 , the timing controller 130 checks whether the luminance of the display panel 170 is changed by the external host during the corresponding frame period. For example, the mobile phone user may change the brightness of the display panel 170 regardless of the displayed image, which is supplied to the timing controller 130 as a predetermined command value by the host. The timing controller 130 resets the counter value to an initial value when the luminance of the display panel 170 is changed during the corresponding frame period.

<Still image display time judgment: S204, S205>

If the luminance of the display panel 170 is not changed in step S203 , the timing controller 130 determines whether the counter value exceeds a third threshold value. The third threshold value is a value indicating a display time of a still image that can be displayed on the display panel 170 within a range in which a non-reconstructed afterimage does not occur. This third threshold is preset to a predetermined time through various experiments. For example, the third threshold value may vary depending on the type, resolution, and inch of the display panel 170 . Also, the setting of the third threshold value may be changed by the user.

If the counter value does not exceed the third threshold in step S204, the counter value is increased. Then, while repeating the above-described steps S200 to S205, a time for displaying the still image on the display panel 170 is checked.

<Comparison of current luminance and critical luminance: S206>

If the counter value exceeds the third threshold in step S204, the timing controller 130 determines whether the current luminance exceeds the threshold luminance. Here, the current luminance means a luminance value that can be displayed currently set in the display panel 170 .

In detail, the luminance of the display panel 170 is set to a specific luminance according to a user's setting, an external environment, or the like. For example, as shown in FIG. 7A , when the highest luminance that can be displayed on the display panel 170 is 450 nits, the display panel 170 is set to a luminance of 450 nits or less. That is, the current luminance is set to various values such as 450 nits, 300 nits, 250 nits, and 150 nits. For example, the user may lower or increase the brightness of the display panel 170 by manipulating the mobile phone.

In addition, the critical luminance refers to a luminance at which a non-restored afterimage does not occur in the display panel 170 . For example, when the highest luminance that can be displayed on the display panel 170 is set to 450 nits, the critical luminance may be set to 225 nits or more, which is 1/2 or more of 450 nits.

When the current luminance of the display panel 170 is lower than the threshold luminance, the still image on the display panel 170 is a predetermined time period (ie, a time period equal to or greater than the third threshold value, for example, two frames or more). ), the probability of non-restored afterimages is lowered. Accordingly, when the current luminance does not exceed the threshold luminance in step S206 , the timing controller 130 does not change the luminance of the display panel 170 (return to step S200).

When the current luminance exceeds the threshold luminance in the display panel 170 , the probability that a non-restored afterimage is generated in the display panel 170 increases. Accordingly, the timing controller 130 proceeds to step S208 so that the luminance of the display panel 170 can be changed.

<Comparison of average grayscale and critical grayscale: S208>

The timing controller 130 receives data of the j frame jF from the outside. The timing controller 130 receiving the data of the j frame jF supplies the data of the j frame jF to the second calculating unit 134 . The second calculator 134 generates the third data Data3 including the average grayscale information by using the data Data of the j frame jF.

The timing controller 130 that has generated the third data Data3 determines whether the average grayscale of the j frame jF exceeds a threshold grayscale. The threshold gray level means a predetermined gray level or more, and may be previously stored in the memory 140 in the form of data. Here, the critical gradation means a gradation to the extent that an unreconstructed afterimage does not occur in the display panel 170 . For example, when the expressible gray level is 256, the critical gray level may be set to 128 gray level or more, which is 1/2 or more of the expressable gray level.

In more detail, when the average grayscale is lower than the threshold luminance on the display panel 170 , the probability of a non-reconstructed afterimage occurring even if the still image is displayed on the display panel 170 for a predetermined time or longer is reduced. Accordingly, if the average gray level does not exceed the threshold gray level in step S208, the timing controller 130 does not change the luminance of the display panel 170 (return to step S200). That is, even if the current luminance exceeds the threshold luminance , if the average gradation of the image displayed on the display panel 170 does not exceed the threshold gradation, the dark image is displayed on the display panel 170, so the probability of an unreconstructed afterimage is low. (If the gradation is divided into 256 levels, As shown in FIG. 7B, 256 gray levels are realized by dividing the current luminance.)

When the average grayscale exceeds the threshold grayscale in the display panel 170 , the probability that an unreconstructed afterimage is generated in the display panel 170 increases. Accordingly, the timing controller 130 proceeds to step S210 so that the luminance of the display panel 170 can be changed.

<Change luminance: S210>

If the average gradation of the display panel 170 exceeds the threshold gradation in step S208 , the timing controller 130 changes the luminance of the display panel 170 to the target luminance. For example, the timing controller 130 may control the bits of data supplied to the data driver 150 to change the luminance of the display panel 170 to a target luminance.

The target luminance means a luminance lower than the current luminance. For example, the target luminance may be set to a luminance equal to or less than a threshold luminance. When the luminance of the display panel 170 is lowered in step S210 , a non-restored afterimage does not occur, and thus display quality can be improved.

As described above, in the present invention, a still image and a moving image may be determined using the memory 140 having a lower capacity than the full frame memory. Also, in the present invention, when a still image is displayed for a predetermined time without a change in the luminance of the display panel 170, the current luminance exceeds the threshold luminance, and the average gradation of the current frame exceeds the threshold gradation, the luminance of the display panel 170 is increased. lower it In this case, the probability that a non-restored afterimage is generated in the display panel 170 may be reduced.

Meanwhile, after changing the luminance of the display panel 170 to the target luminance, the timing controller 130 changes the luminance of the display panel 170 to the desired luminance (for example, if a moving image is displayed on the display panel 170 ). , the luminance set by the user). Also, when the current luminance exceeds the threshold luminance, the timing controller 130 changes the luminance of the display panel 170 to the luminance to be originally expressed.

8 is a diagram illustrating an embodiment of changing the luminance of a display panel. 8 illustrates a case in which the luminance of the display panel is changed to a target luminance at a time T1, and the luminance of the display panel returns to a current luminance at a time T2.

Referring to FIG. 8 , the timing controller 130 may directly change the luminance of the display panel 170 from the current luminance to the target luminance at a time T1. (Dimming off) In addition, the timing controller 130 displays the display from the time T1. The luminance of the panel 170 may be changed to be gradually lowered from the current luminance to the target luminance. (Dimming on)

When the luminance is immediately changed from the current luminance to the target luminance, the probability that a non-restored afterimage is generated in the display panel 170 may be minimized. In addition, when the luminance is gradually changed from the current luminance to the target luminance, it is possible to prevent the user from recognizing the sudden luminance change of the display panel 170 .

Similarly, the timing controller 130 may directly change the luminance of the display panel 170 from the target luminance to the current luminance at the time T2. (Dimming off) Also, the timing controller 130 controls the display panel 170 at the time T2. It is possible to change the luminance to increase step by step from the target luminance to the current luminance. (Dimming on)

As described above, in the present invention, the luminance of the display panel 170 may be rapidly changed or may be changed in stages. That is, the present invention includes various methods of changing the luminance of the display panel 170 , and thus convenience can be increased.

FIG. 9 is a diagram illustrating an embodiment of the sub-pixel shown in FIG. 1 . In FIG. 9 , sub-pixels connected to the first scan line SL1 and the first data line DL1 are illustrated for convenience of explanation.

Referring to FIG. 9 , the sub-pixel SP according to the embodiment of the present invention includes a switching transistor SW connected to a first scan line SL1 and a first data line DL1 and a switching transistor SW via the first scan line SL1 and the first data line DL1. and a pixel circuit PC driven in response to the supplied data signal.

The switching transistor SW is turned on when a scan signal is supplied to the first scan line SL1 . When the switching transistor SW is turned on, the data signal from the first data line DL1 is supplied to the pixel circuit PC. Then, the pixel circuit PC stores the data signal and emits light of a predetermined gradation in response to the stored data signal.

The pixel circuit PC may be implemented as various types of circuits. For example, when the display panel 170 is formed of an organic light emitting display panel, the pixel circuit PC may be implemented with various types of circuits including a driving transistor and a storage capacitor. In addition, when the display panel 170 is configured as a liquid crystal display panel, the pixel circuit PC may be implemented to include a storage capacitor.

When the display panel 170 is configured as a liquid crystal display panel, a twisted nematic (TN) mode, a vertical alignment (VA) mode, an IPS (in plane switching) mode, a fringe field switching (FFS) mode, or an electrically controlled birefringence (ECB) mode mode can be implemented. When the display panel 170 is configured as an organic light emitting display panel, this may be implemented in a top-emission method, a bottom-emission method, or a dual-emission method.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention can be changed to other specific forms by those skilled in the art to which the present invention pertains without changing the technical spirit or essential features of the present invention. It will be appreciated that this may be practiced. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. In addition, the scope of the present invention is indicated by the claims to be described later rather than the above detailed description. In addition, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

130: timing control unit 132, 134: calculation unit
140: memory 150: data driver
160: scan driver 170: display panel

Claims (12)

The data of the current frame input from the outside is divided into k (k is a natural number) bit first data corresponding to the horizontal line of the panel, and the first data is divided into i (i is a first calculation unit for converting the second data of bits (a natural number less than k) into bit second data; extracting luminance information in units of pixels from the data of the current frame; a timing controller including a second calculator for generating third data including information;
a memory for storing second data of a previous frame;
The timing control unit,
Comparing the second data of the previous frame and the second data of the current frame in units of the horizontal line, a pixel change rate of the second data of the current frame with respect to the second data of the previous frame is obtained, and the pixel change rate and the second data of the current frame are obtained in advance. By comparing the set first threshold, it is determined whether the second data of the current frame is changed or not in the corresponding horizontal line, and the data of the current frame input from the outside is k (k is a natural number) corresponding to the horizontal line of the panel. ) a first calculation unit for dividing the first data into bits and converting the first data into second data of i (i is a natural number less than k) bits using a CRC (Cyclic Redundancy Check) method; a timing control unit including a second calculator for extracting luminance information from data of the current frame in units of pixels, averaging the luminance information in units of pixels to generate third data including average grayscale information of the current frame;
a memory for storing second data of a previous frame;
The timing control unit,
Comparing the second data of the previous frame and the second data of the current frame in units of the horizontal line, a pixel change rate of the second data of the current frame with respect to the second data of the previous frame is obtained, and the pixel change rate and the second data of the current frame are obtained in advance. It is determined whether the second data of the current frame is changed or not changed in the corresponding horizontal line by comparing the set first threshold value,
It is determined whether the image displayed on the panel is a still image or a moving image by comparing the change rate of the second data of the current frame with a preset second threshold based on one frame,
When the image is displayed as a still image, it is checked whether the luminance of the panel is changed during the frame period, and when the luminance is changed, the counter value is reset to an initial value, and when the luminance is not changed, the counter value is not changed. increasing the counter value by comparing the value with a predetermined third threshold value, or comparing the current luminance with a preset threshold luminance;
The display device according to claim 1, wherein the luminance of the panel is changed or not changed by comparing the average grayscale of the current frame with a preset threshold grayscale according to the comparison of the current luminance with a preset threshold luminance. The method of claim 1,
The display device of claim 1, wherein the first threshold value is set corresponding to the CRC (Cyclic Redundancy Check) method. delete The method of claim 1,
When the change rate of the second data exceeds the second threshold, the timing controller determines that the moving image is displayed on the panel, and in other cases, determines that the still image is displayed on the panel Characteristic display device. delete The method of claim 1,
The timing controller is configured to display the still image without changing the luminance of the panel for a predetermined period of time, and when the luminance of the panel exceeds a preset threshold luminance, and the average gradation information of the third data exceeds a preset threshold gradation, the A display device, characterized in that it lowers the luminance of the panel. converting k (k is a natural number) bit first data corresponding to the horizontal line of the panel into i (i is a natural number less than k) bit second data using a CRC (Cyclic Redundancy Check) method;
extracting luminance information in units of pixels from data of the current frame and averaging the luminance information in units of pixels to extract an average grayscale of the current frame;
By comparing the second data of the previous frame with the second data of the current frame in units of the horizontal line, a pixel change rate of the second data of the current frame with respect to the second data of the previous frame is obtained, and the pixel change rate and a preset rate of change are obtained. determining whether the second data of the current frame is changed or not changed in the corresponding horizontal line by comparing the first threshold;
determining whether the image displayed on the panel is a still image or a moving image by comparing the change rate of the second data of the current frame with a preset second threshold based on one frame;
When the image is displayed as a still image, it is checked whether the luminance of the display panel is changed during a corresponding frame period, and when the luminance is changed, the counter value is reset to an initial value, and when the luminance is not changed, the increasing the counter value by comparing the counter value with a third predetermined threshold value, or comparing the luminance with a preset threshold luminance;
and changing or not changing the luminance of the panel by comparing the average grayscale of the current frame with a preset threshold grayscale according to the comparison result. 8. The method of claim 7,
The method of claim 1, wherein the first threshold value is set corresponding to the CRC (Cyclic Redundancy Check) method. delete 8. The method of claim 7,
When the rate of change of the second data in the current frame exceeds a preset second threshold, it is determined that the moving image is displayed on the panel, and in other cases, it is determined that the still image is displayed on the panel A method of driving a display device, characterized in that. delete 8. The method of claim 7,
When the still image is displayed for a predetermined time without changing the luminance of the panel, the luminance of the panel exceeds a preset threshold luminance, and the average gradation of the current frame exceeds a preset threshold luminance, lowering the luminance of the panel A method of driving a display device.

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