Display device and method for detecting still image in display device

Abstract

The present application relates to a display device and a method for detecting a still image in the display device. The display device includes: a display panel including a plurality of pixels and a panel driver including N registers, wherein N is an integer greater than 1. The panel driver is configured to divide the display panel into N first detection areas, perform a first still image detection operation on each of the N first detection areas by using the N registers, divide the display panel into N second detection areas different from the N first detection areas by using a result of the first still image detection operation, and perform a second still image detection operation on each of the N second detection areas by using the N registers.

Description

Technical Field

[0001] Exemplary embodiments of the inventive concept relate to a display device, and more particularly, to a display device that performs still image detection and a method of detecting a still image in the display device. Background Art

[0002] In display devices used in portable devices such as smartphones and tablet computers, it is desirable to reduce power consumption. In order to reduce the power consumption of display devices, a low-frequency driving technology has been developed that drives or refreshes a display panel at a frequency lower than the normal driving frequency by analyzing input image data. However, in conventional display devices to which the low-frequency driving technology is applied, when a still image is not displayed in the entire area of the display panel, or when a still image is displayed only in a partial area of the display panel, the entire area of the display panel may be driven at the normal driving frequency. Therefore, in this case, low-frequency driving may not be performed, and power consumption may not be reduced.

[0003] Recently, in order to reduce power consumption even when a still image is displayed in only a partial area of a display panel, a multi-frequency driving (MFD) technology is being developed that drives the still image area and the moving image area of the display panel at different driving frequencies. To perform this multi-frequency driving, the display device may store image data of the previous frame period in a frame memory, and may compare the image data of the current frame period with the image data stored in the frame memory to divide the display panel into a still image area and a moving image area. In other words, a conventional display device that performs the multi-frequency driving technology requires a frame memory to detect the still image area in the partial area of the display panel. Summary of the Invention

[0004] According to an exemplary embodiment of the present inventive concept, a display device includes: a display panel including a plurality of pixels; and a panel driver including N registers, where N is an integer greater than 1. The panel driver divides the display panel into N first detection areas, performs a first still image detection operation on each of the N first detection areas by using the N registers, divides the display panel into N second detection areas different from the N first detection areas by using a result of the first still image detection operation, and performs a second still image detection operation on each of the N second detection areas by using the N registers.

[0005] In an exemplary embodiment of the present inventive concept, the panel driver may equally divide input image data for the display panel into N first detection area image data having the same size for the N first detection areas in the first and second frame periods.

[0006] In an exemplary embodiment of the present inventive concept, in a first frame period, the panel driver may calculate previous representative values of N first detection area image data and may store the previous representative values in N registers. In a second frame period, the panel driver may calculate current representative values of the N first detection area image data and perform a first still image detection operation of determining whether each of the N first detection areas is a still image area or a moving image area by comparing the current representative values with the previous representative values stored in the N registers.

[0007] In an exemplary embodiment of the present inventive concept, each of the previous representative value and the current representative value may be a checksum value of a corresponding one of the N first detection area image data.

[0008] In an exemplary embodiment of the present inventive concept, each of the previous representative value and the current representative value may be an average value of a corresponding one of the N first detection area image data.

[0009] In an exemplary embodiment of the present inventive concept, each of the previous representative value and the current representative value may be a sum value of a corresponding one of the N first detection area image data.

[0010] In an exemplary embodiment of the present invention, in the third frame period and the fourth frame period, the panel driver may set the still image area detected by the first still image detection operation as one of the N second detection areas, may set the remaining N-1 detection areas of the N second detection areas having the same size by equally dividing the motion image area detected by the first still image detection operation, and may divide the input image data for the display panel into N second detection area image data for the N second detection areas.

[0011] In an exemplary embodiment of the present inventive concept, in a third frame period, the panel driver may calculate previous representative values of the N second detection area image data and may store the previous representative values in N registers. In a fourth frame period, the panel driver may calculate current representative values of the N second detection area image data and perform a second still image detection operation of determining whether each of the N second detection areas is a still image area or a moving image area by comparing the current representative values with the previous representative values stored in the N registers.

[0012] In an exemplary embodiment of the present invention, when the still image area detected by the first still image detection operation and the still image area detected by the second still image detection operation are different from each other, the panel driver may set the still image area detected by the second still image detection operation as one of the N third detection areas, may set the remaining N-1 detection areas of the N third detection areas having the same size by equally dividing the motion image area detected by the second still image detection operation, and may perform the third still image detection operation on each of the N third detection areas by using N registers.

[0013] In an exemplary embodiment of the present invention, when the still image area detected by the first still image detection operation and the still image area detected by the second still image detection operation are substantially the same as each other, the panel driver may increase the still image area detected by the second still image detection operation by M pixels in the first direction, where M is an integer greater than 0, and may set the still image area detected by the second still image detection operation with the M pixels increased as one of the N third detection areas, and may reduce the motion image area detected by the second still image detection operation by M pixels in the first direction, and may set the remaining N-1 detection areas of the N third detection areas having the same size by equally dividing the motion image area reduced by M pixels, and may perform the third still image detection operation on each of the N third detection areas by using N registers.

[0014] In an exemplary embodiment of the present invention, when a still image area is detected by a third still image detection operation, the panel driver may further increase the still image area detected by the third still image detection operation by M pixels in the first direction, may set the still image area detected by the third still image detection operation with the further increase of M pixels as one of the N fourth detection areas, may further reduce the motion image area detected by the third still image detection operation by M pixels in the first direction, may set the remaining N-1 detection areas of the N fourth detection areas having the same size by equally dividing the motion image area detected by the third still image detection operation with the further reduction of M pixels, and may perform the fourth still image detection operation on each of the N fourth detection areas by using N registers.

[0015] In an exemplary embodiment of the present invention, when all third detection areas are determined as motion image areas, the panel driver may set the N second detection areas used in the second still image detection operation as N fourth detection areas, and may perform the fourth still image detection operation on each of the N fourth detection areas by using N registers.

[0016] In an exemplary embodiment of the present inventive concept, the panel driver may continuously use the N fourth detection areas until the still image area detected by the fourth still image detection operation is changed, and may reset the N fourth detection areas when the still image area detected by the fourth still image detection operation is changed.

[0017] In an exemplary embodiment of the inventive concept, the panel driver may drive the moving image area detected by the fourth still image detection operation at a first driving frequency, and may drive the still image area detected by the fourth still image detection operation at a second driving frequency lower than the first driving frequency.

[0018] According to an exemplary embodiment of the present invention, in a method for detecting a still image in a display device including N registers, where N is an integer greater than 1, a display panel of the display device is divided into N first detection areas, a first still image detection operation is performed on each of the N first detection areas by using the N registers, the display panel is divided into N second detection areas different from the N first detection areas by using a result of the first still image detection operation, and a second still image detection operation is performed on each of the N second detection areas by using the N registers.

[0019] In an exemplary embodiment of the present inventive concept, in order to divide a display panel into N first detection areas, input image data for the display panel may be equally divided into N first detection area image data having the same size for the N first detection areas in a first frame period and a second frame period. In order to perform a first still image detection operation, previous representative values of the N first detection area image data may be calculated in the first frame period, the previous representative values may be stored in N registers in the first frame period, current representative values of the N first detection area image data may be calculated in the second frame period, and the first still image detection operation may be performed in the second frame period to determine whether each of the N first detection areas is a still image area or a moving image area by comparing the current representative values with the previous representative values stored in the N registers.

[0020] In an exemplary embodiment of the present inventive concept, to divide a display panel into N second detection areas, a still image area detected by a first still image detection operation may be set as one of the N second detection areas during a third frame period and a fourth frame period, the remaining N-1 detection areas of the N second detection areas having the same size may be set by equally dividing the moving image area detected by the first still image detection operation during the third frame period and the fourth frame period, and input image data for the display panel may be divided into N second detection area image data for the N second detection areas. To perform a second still image detection operation, a previous representative value of the N second detection area image data may be calculated during a third frame period, the previous representative value may be stored in N registers during the third frame period, a current representative value of the N second detection area image data may be calculated during a fourth frame period, and a second still image detection operation may be performed to determine whether each of the N second detection areas is a still image area or a moving image area by comparing the current representative value with the previous representative value stored in the N registers during the fourth frame period.

[0021] In an exemplary embodiment of the present invention, when the still image area detected by the first still image detection operation and the still image area detected by the second still image detection operation are different from each other, the still image area detected by the second still image detection operation can be set as one of N third detection areas, the remaining N-1 detection areas of the N third detection areas having the same size can be set by equally dividing the moving image area detected by the second still image detection operation, and the third still image detection operation can be performed on each of the N third detection areas by using N registers.

[0022] In an exemplary embodiment of the present invention, when the still image area detected by the first still image detection operation and the still image area detected by the second still image detection operation are substantially the same as each other, the still image area detected by the second still image detection operation may be increased by M pixels in the first direction, where M is an integer greater than 0, the still image area detected by the second still image detection operation with the M pixels increased may be set as one of N third detection areas, the motion image area detected by the second still image detection operation may be reduced by M pixels in the first direction, the remaining N-1 detection areas of the N third detection areas with the same size may be set by equally dividing the motion image area with the M pixels reduced, and the third still image detection operation may be performed on each of the N third detection areas by using N registers.

[0023] In an exemplary embodiment of the present invention, when all N third detection areas are determined to be motion image areas, the N second detection areas used in the second still image detection operation can be set as N fourth detection areas, a fourth still image detection operation can be performed on each of the N fourth detection areas by using N registers, and when the still image area detected by the fourth still image detection operation is changed, the N fourth detection areas can be reset.

[0024] According to an exemplary embodiment of the present inventive concept, in a method for detecting a still image in a display device, during a first frame period and a second frame period, a display panel of the display device is equally divided into N first detection areas, and input image data is equally divided into N first detection area image data, where N is an integer greater than 1. Previous representative values of the N first detection area image data are stored during the first frame period. During a second frame period, a current representative value of the N first detection area image data is calculated, and a first still image detection operation is performed to determine whether each of the N first detection areas is a still image area or a moving image area by comparing the current representative value with the previous representative value. During a third frame period and a fourth frame period, at least two of the N first detection areas are set as one detection area of the N second detection areas, and the remaining portion of the N first detection areas is equally divided into the remaining N-1 detection areas of the N second detection areas. During a fourth frame period, a second still image detection operation is performed to determine whether each of the N second detection areas is a still image area or a moving image area. Summary of the Invention

[0026] The above and other features of the present inventive concept will be more clearly understood by describing in detail exemplary embodiments of the present inventive concept with reference to the accompanying drawings.

[0027] Figure 1 is a block diagram illustrating a display device according to an exemplary embodiment of the inventive concept.

[0028] Figure 2 is a block diagram illustrating a controller included in a display device according to an exemplary embodiment of the inventive concept.

[0029] Figure 3 is a diagram showing an exemplary embodiment according to the present inventive concept Figure 2 A block diagram of a linear feedback shift register (LFSR) included in a controller.

[0030] Figure 4 is a block diagram illustrating a controller included in a display device according to an exemplary embodiment of the inventive concept.

[0031] Figure 5 is a block diagram illustrating a controller included in a display device according to an exemplary embodiment of the inventive concept.

[0032] Figure 6 is a diagram for describing an operation of a still image detection block included in a display device according to an exemplary embodiment of the inventive concept.

[0033] Figure 7 is a diagram illustrating a flicker lookup table included in a display device according to an exemplary embodiment of the inventive concept.

[0034] Figure 8 is a diagram for describing an operation of a driving frequency determination block included in a display device according to an exemplary embodiment of the inventive concept.

[0035] Figure 9 is a diagram for describing an example of driving a display panel in a display device according to an exemplary embodiment of the inventive concept.

[0036] Figure 10 is a flowchart illustrating a method of detecting a still image in a display device according to an exemplary embodiment of the inventive concept.

[0037] Figure 11 is a block diagram illustrating an electronic device including a display device according to an exemplary embodiment of the inventive concept. DETAILED DESCRIPTION

[0038] Exemplary embodiments of the present inventive concept provide a display device capable of efficiently performing a still image detection operation without using a frame memory.

[0039] Exemplary embodiments of the present inventive concept also provide a method of detecting a still image in a display device capable of efficiently performing a still image detection operation without using a frame memory.

[0040] Hereinafter, exemplary embodiments of the inventive concept will be explained in detail with reference to the accompanying drawings.Throughout this application, like drawing numbers may refer to like elements.

[0041] Figure 1 is a block diagram illustrating a display device 100 according to an exemplary embodiment of the inventive concept. Figure 2 is a block diagram illustrating a controller 150 a included in a display device according to an exemplary embodiment of the inventive concept. Figure 3 It is shown that the Figure 2 1 is a block diagram of a linear feedback shift register (LFSR) 200 in the controller 150a. Figure 4is a block diagram illustrating a controller 150 b included in a display device according to an exemplary embodiment of the inventive concept. Figure 5 is a block diagram illustrating a controller 150 c included in a display device according to an exemplary embodiment of the inventive concept. Figure 6 is a diagram for describing an operation of the still image detection block 170 a included in the display device according to an exemplary embodiment of the inventive concept. Figure 7 is a diagram illustrating a flicker lookup table 190 included in a display device according to an exemplary embodiment of the inventive concept. Figure 8 is a diagram for describing an operation of the driving frequency decision block 180 included in the display device according to an exemplary embodiment of the inventive concept. Figure 9 is a diagram for describing an example of driving the display panel 110 in a display device according to an exemplary embodiment of the inventive concept.

[0042] Reference Figure 1 According to an exemplary embodiment of the present inventive concept, a display device 100 may include a display panel 110 including a plurality of pixels PX, and a panel driver 120 driving the display panel 110. In an exemplary embodiment of the present inventive concept, the panel driver 120 may include a data driver 130 that provides a data signal DS to the plurality of pixels PX, a scan driver 140 that provides a scan signal SS to the plurality of pixels PX, and a controller 150 that controls the data driver 130 and the scan driver 140.

[0043] The display panel 110 may include a plurality of data lines, a plurality of scan lines, and a plurality of pixels PX coupled to the plurality of data lines and the plurality of scan lines. In an exemplary embodiment of the present invention, each pixel PX may include at least one capacitor, at least two transistors, and an organic light emitting diode (OLED), and the display panel 110 may be an OLED display panel. In addition, in an exemplary embodiment of the present invention, each pixel PX may be a hybrid oxide polycrystalline (HOP) pixel suitable for low-frequency driving that can reduce power consumption. For example, in a HOP pixel, at least one first transistor may be implemented using a low-temperature polycrystalline silicon (LTPS) PMOS transistor, and at least one second transistor may be implemented using an oxide NMOS transistor. In an exemplary embodiment of the present invention, the display panel 110 may be a liquid crystal display (LCD) panel or any other suitable display panel.

[0044] The data driver 130 may generate a data signal DS based on the output image data ODAT and the data control signal DCTRL received from the controller 150, and may provide the data signal DS to a plurality of pixels PX via a plurality of data lines. In an exemplary embodiment of the present invention, the data control signal DCTRL may include, but is not limited to, an output data enable signal, a horizontal start signal, and a load signal. In an exemplary embodiment of the present invention, the data driver 130 and the controller 150 may be implemented using a single integrated circuit, and the integrated circuit may be referred to as a timing controller embedded data driver (TED). In an exemplary embodiment of the present invention, the data driver 130 and the controller 150 may be implemented using separate integrated circuits.

[0045] The scan driver 140 may generate a scan signal SS based on a scan control signal SCTRL received from the controller 150, and may provide the scan signal SS to a plurality of pixels PX via a plurality of scan lines. In an exemplary embodiment of the present invention, the scan driver 140 may sequentially provide the scan signal SS to the plurality of pixels PX on a row-by-row basis. Furthermore, in an exemplary embodiment of the present invention, the scan control signal SCTRL may include, but is not limited to, a scan start signal and a scan clock signal. In an exemplary embodiment of the present invention, the scan driver 140 may be integrated or formed in a peripheral portion of the display panel 110. In an exemplary embodiment of the present invention, the scan driver 140 may be implemented using one or more integrated circuits.

[0046] The controller 150 (e.g., a timing controller (TCON)) may receive input image data IDAT and a control signal CTRL from an external host processor (e.g., an application processor (AP), a graphics processing unit (GPU), or a graphics card). In exemplary embodiments of the present inventive concept, the input image data IDAT may be, but is not limited to, RGB image data including red image data, green image data, and blue image data. In exemplary embodiments of the present inventive concept, the control signal CTRL may include, but is not limited to, a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a main clock signal, and the like. Based on the input image data IDAT and the control signal CTRL, the controller 150 may generate output image data ODAT, a data control signal DCTRL, and a scan control signal SCTRL. The controller 150 may control the operation of the data driver 130 by providing the output image data ODAT and the data control signal DCTRL to the data driver 130, and may control the operation of the scan driver 140 by providing the scan control signal SCTRL to the scan driver 140.

[0047] In the display device 100 according to an exemplary embodiment of the present inventive concept, the panel driver 120 may include N registers 160, and may effectively perform a still image detection operation that divides the display panel 110 into a still image area and a moving image area by dynamically changing the detection areas respectively corresponding to the N registers 160. Here, N may be an integer greater than 1 and may be less than or equal to the number of rows of pixels PX of the display panel 110.

[0048] In an exemplary embodiment of the present invention, the panel driver 120 may divide the display panel 110 into N first detection areas and may perform a first still image detection operation on each of the plurality of first detection areas using N registers 160. Here, the division of the display panel 110 may not be a physical division of the display panel 110, but rather a logical division of the display panel 110, and may include dividing the input image data IDAT for the display panel 110 into detection area image data for each of the plurality of detection areas. Furthermore, the panel driver 120 may divide the display panel 110 into N second detection areas different from the first detection areas using the results of the first still image detection operation and may perform a second still image detection operation on each of the plurality of second detection areas using the N registers 160. Therefore, the display device 100 according to an exemplary embodiment of the present invention may not use a frame memory and may finely detect still image areas using a limited number of registers 160.

[0049] In an exemplary embodiment of the present inventive concept, Figure 2 As shown, the controller 150 a may include N registers 160 (eg, four registers 161 , 162 , 163 , and 164 ), a still image detection block 170 a , a driving frequency determination block 180 , and a flicker lookup table (LUT) 190 .

[0050] The still image detection block 170a may divide the display panel 110 into four detection areas corresponding to the four registers 161, 162, 163, and 164, respectively, and may determine whether each of the four detection areas is a still image area or a moving image area. In an exemplary embodiment of the present inventive concept, the four registers 161, 162, 163, and 164 may store four previous representative values of four detection area image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4 for the four detection areas in a previous frame period. The still image detection block 170a may calculate four current representative values of the four detection area image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4 in a current frame period, and perform a still image detection operation to determine whether each of the four detection areas is a still image area or a moving image area by comparing the four current representative values with the four previous representative values stored in the four registers 161, 162, 163, and 164.

[0051] In an exemplary embodiment of the present inventive concept, Figure 2 As shown, the four previous representative values may be four previous checksum values PCSV1, PCSV2, PCSV3, and PCSV4, and the four current representative values may be four current checksum values CCSV1, CCSV2, CCSV3, and CCSV4. For example, in order to perform a still image detection operation by comparing the four current checksum values CCSV1, CCSV2, CCSV3, and CCSV4 with the four previous checksum values PCSV1, PCSV2, PCSV3, and PCSV4, as shown in FIG. Figure 2 As shown, the still image detection block 170 a may include a detection region setting block 171 , N (eg, four) linear feedback shift registers (LFSRs) 172 a , 173 a , 174 a , and 175 a , and a representative value comparison block 176 .

[0052] The detection area setting block 171 can dynamically set four detection areas corresponding to the four registers 161, 162, 163 and 164 respectively by using the results of the previous still image detection operation, and can divide the input image data IDAT for the display panel 110 into four detection area image data DRDAT1, DRDAT2, DRDAT3 and DRDAT4 for the four detection areas.

[0053] The four linear feedback shift registers 172a, 173a, 174a and 175a can calculate four current representative values or four current checksum values CCSV1, CCSV2, CCSV3 and CCSV4 of the four detection area image data DRDAT1, DRDAT2, DRDAT3 and DRDAT4. Figure 3 As shown, each of the four linear feedback shift registers 172 a, 173 a, 174 a, and 175 a may include K flip-flops (FFs) 211, 212, 223, ..., 214 and K XOR gates 221, 222, 223, ..., 224, where K is an integer greater than 1. The K flip-flops 211, 212, 213, ..., 214 may store initial values or seed signals, the K XOR gates 221, 222, 223, ..., 224 may perform an XOR operation on the seed signal and K bits of the detection area image data DRDAT (e.g., DRDAT1, DRDAT2, DRDAT3, or DRDAT4), and the K flip-flops 211, 212, 223, ..., 214 may shift the result of the XOR operation by a predetermined number of bits. Then, the next XOR operation may be performed on the current values of the K flip-flops 211, 212, 223, ..., 214 and the next K bits of the detection area image data DRDAT, and the result of the next XOR operation may be shifted by a predetermined number of bits. These XOR and shift operations may be repeated until the XOR and shift operations are performed on all bits of the detection area image data DRDAT, and the result is the current checksum value (e.g., CCSV1) of the detection area image data DRDAT. Although Figure 3 An example of each linear feedback shift register 200 including K flip-flops 211, 212, 223, ..., 214 and K XOR gates 221, 222, 223, ..., 224 is shown, but the configuration of the linear feedback shift register 200 is not limited to Figure 3 .

[0054] The representative value comparison block 176 can determine whether each of the four detection areas is a still image area or a moving image area by comparing the four current checksum values CCSV1, CCSV2, CCSV3, and CCSV4 with the four previous checksum values PCSV1, PCSV2, PCSV3, and PCSV4, respectively. For example, if the current checksum value for the detection area (e.g., CCSV1) is substantially the same as the previous checksum value for the detection area (e.g., PCSV1), the representative value comparison block 176 can determine that the detection area is a still image area, and if the current checksum value for the detection area (e.g., CCSV1) is different from the previous checksum value for the detection area (e.g., PCSV1), the representative value comparison block 176 can determine that the detection area is a moving image area. In addition, the representative value comparison block 176 can store the four current checksum values CCSV1, CCSV2, CCSV3 and CCSV4 in the four registers 161, 162, 163 and 164 so that the four current checksum values CCSV1, CCSV2, CCSV3 and CCSV4 are used as the four previous checksum values PCSV1, PCSV2, PCSV3 and PCSV4 in the next frame period.

[0055] In an exemplary embodiment of the present inventive concept, Figure 4 As shown, for the controller 150b, the four previous representative values may be the four previous average values PAVGV1, PAVGV2, PAVGV3, and PAVGV4, and the four current representative values may be the four current average values CAVGV1, CAVGV2, CAVGV3, and CAVGV4. For example, in order to perform a still image detection operation by comparing the four current average values CAVGV1, CAVGV2, CAVGV3, and CAVGV4 with the four previous average values PAVGV1, PAVGV2, PAVGV3, and PAVGV4, as shown in FIG. Figure 4 As shown, the still image detection block 170b of the controller 150b may include a detection area setting block 171, N (e.g., four) averaging calculators 172b, 173b, 174b, and 175b, and a representative value comparison block 176. Each averaging calculator (e.g., 172b) may calculate a corresponding current average value (e.g., CAVGV1) by averaging the gray levels represented by the corresponding detection area image data (e.g., DRDAT1). The representative value comparison block 176 may determine whether each of the four detection areas is a still image area or a moving image area by comparing the four current average values CAVGV1, CAVGV2, CAVGV3, and CAVGV4 with the four previous average values PAVGV1, PAVGV2, PAVGV3, and PAVGV4, respectively.

[0056] In an exemplary embodiment of the present inventive concept, Figure 5 As shown, for the controller 150c, the four previous representative values may be the four previous sum values PSUMV, PSUMV2, PSUMV3, and PSUMV4, and the four current representative values may be the four current sum values CSUMV1, CSUMV2, CSUMV3, and CSUMV4. For example, in order to perform a still image detection operation by comparing the four current sum values CSUMV1, CSUMV2, CSUMV3, and CSUMV4 with the four previous sum values PSUMV1, PSUMV2, PSUMV3, and PSUMV4, as shown in FIG. Figure 5 As shown, the still image detection block 170c of the controller 150c may include a detection area setting block 171, N (e.g., four) summation calculators 172c, 173c, 174c, and 175c, and a representative value comparison block 176. Each summation calculator (e.g., 172c) may calculate a corresponding current sum value (e.g., CSUMV1) by summing the gray levels represented by the corresponding detection area image data (e.g., DRDAT1). The representative value comparison block 176 may determine whether each of the four detection areas is a still image area or a moving image area by comparing the four current sum values CSUMV1, CSUMV2, CSUMV3, and CSUMV4 with the four previous sum values PSUMV1, PSUMV2, PSUMV3, and PSUMV4, respectively.

[0057] Reference Figure 1 、 Figure 2 and Figure 6 In an exemplary embodiment of the present inventive concept, the still image detection block 170 a may effectively perform a still image detection operation by dynamically changing four detection areas corresponding to the four registers 161 , 162 , 163 , and 164 , respectively.

[0058] For example, in the first frame period FP1 and the second frame period FP2, the still image detection block 170a may divide the display panel 110a into four first detection areas DR1a, DR2a, DR3a, and DR4a, and may perform the first still image detection on each of the four first detection areas DR1a, DR2a, DR3a, and DR4a by using four registers 161, 162, 163, and 164.

[0059] As an example, in the first frame period FP1 and the second frame period FP2, the detection area setting block 171 may equally divide the display panel 110a into four first detection areas DR1a, DR2a, DR3a, and DR4a along a column direction (e.g., a direction of data lines), and may equally divide the input image data IDAT for the display panel 110a into four first detection area image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4 for the four first detection areas DR1a, DR2a, DR3a, and DR4a having substantially the same size. The four registers 161, 162, 163, and 164 may store previous representative values (e.g., PCSV1, PCSV2, PCSV3, and PCSV4) of the four first detection area image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4 in the first frame period FP1. In the second frame period FP2, the still image detection block 170a can calculate the current representative values (e.g., CCSV1, CCSV2, CCSV3, and CCSV4) of the four first detection area image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4, and can perform a first still image detection operation to determine whether each of the four first detection areas DR1a, DR2a, DR3a, and DR4a is a still image area or a moving image area by comparing the current representative values (e.g., CCSV1, CCSV2, CCSV3, and CCSV4) with the previous representative values (e.g., PCSV1, PCSV2, PCSV3, and PCSV4) stored in the four registers 161, 162, 163, and 164.

[0060] In the third frame period FP3 and the fourth frame period FP4, the still image detection block 170a can divide the display panel 110b into four second detection areas DR1b, DR2b, DR3b and DR4b that are different from the four first detection areas DR1a, DR2a, DR3a and DR4a by using the result of the first still image detection operation, and can perform a second still image detection operation on each of the four second detection areas DR1b, DR2b, DR3b and DR4b by using four registers 161, 162, 163 and 164.

[0061] As an example, in the third frame period FP3 and the fourth frame period FP4, the detection area setting block 171 may set the plurality of still image areas DR3a and DR4a detected by the first still image detection operation as one detection area DR4b of the four second detection areas DR1b, DR2b, DR3b, and DR4b, may set the remaining three detection areas DR1b, DR2b, and DR3b of the four second detection areas DR1b, DR2b, DR3b, and DR4b having substantially the same size by equally dividing the plurality of moving image areas DR1a and DR2a detected by the first still image detection operation, and may divide the input image data IDAT for the display panel 110b into four second detection area image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4 for the four second detection areas DR1b, DR2b, DR3b, and DR4b. In other words, at least two of the plurality of first detection areas (e.g., DR3a and DR4a) may be set as one detection area (e.g., DR4b) of the plurality of second detection areas. The remaining portion of the plurality of first detection regions (e.g., DR1a and DR2a) may be equally divided into N-1 detection regions (e.g., DR1b, DR2b, and DR3b) among the plurality of second detection regions. The four registers 161, 162, 163, and 164 may store previous representative values (e.g., PCSV1, PCSV2, PCSV3, and PCSV4) of the four second detection region image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4 in the third frame period FP3. In the fourth frame period FP4, the still image detection block 170a can calculate the current representative values (e.g., CCSV1, CCSV2, CCSV3, and CCSV4) of the four second detection area image data DRDAT1, DRDAT2, DRDAT3, and DRDAT4, and can perform a second still image detection operation of determining whether each of the four second detection areas DR1b, DR2b, DR3b, and DR4b is a still image area or a moving image area by comparing the current representative values (e.g., CCSV1, CCSV2, CCSV3, and CCSV4) with the previous representative values (e.g., PCSV1, PCSV2, PCSV3, and PCSV4) stored in the four registers 161, 162, 163, and 164.

[0062] Changing the detection area so that a detection area is assigned to the still image area detected by the previous still image detection operation can be performed and repeated until the still image area detected by the current still image detection operation is substantially the same as the still image area detected by the previous still image detection operation.

[0063] For example, in a case where the still image areas (e.g., DR3a and DR4a, or DR4b) detected by a previous still image detection operation (e.g., the first still image detection operation) are different from the still image areas (e.g., DR3b and DR4b) detected by a current still image detection operation (e.g., the second still image detection operation), in the fifth frame period FP5 and the sixth frame period FP6 after the third frame period FP3 and the fourth frame period FP4, the detection area setting block 171 may set the multiple still image areas DR3b and DR4b detected by the second still image detection operation as one detection area DR4c of the four third detection areas DR1c, DR2c, DR3c and DR4c of the display panel 110c, and may set the remaining three detection areas DR1c, DR2c, DR3c and DR4c of the four third detection areas DR1c, DR2c, DR3c and DR4c having substantially the same size by equally dividing the multiple motion image areas DR1b and DR2b detected by the second still image detection operation. In the fifth and sixth frame periods FP5 and FP6 , the still image detection block 170 a may perform a third still image detection operation on each of the four third detection regions DR1 c , DR2 c , DR3 c , and DR4 c by using the four registers 161 , 162 , 163 , and 164 .

[0064] In a case where the still image area (e.g., DR3b and DR4b, or DR4c) detected by a previous still image detection operation (e.g., the second still image detection operation) and the still image area (e.g., DR4c) detected by a current still image detection operation (e.g., the third still image detection operation) are substantially identical to each other, the still image detection block 170a may gradually increase the detection area allocated to the still image area every two frame periods. For example, in the seventh frame period FP7 and the eighth frame period FP8 after the fifth frame period FP5 and the sixth frame period FP6, the detection area setting block 171 may increase the still image area (e.g., DR4c) detected by the third still image detection operation by M pixels in the column direction (e.g., the direction of the data line), where M is an integer greater than 0, and may set the still image area with the M pixels increased as one detection area DR4d of the four fourth detection areas DR1d, DR2d, DR3d, and DR4d of the display panel 110d, and may reduce the motion image area (e.g., DR1c, DR2c, and DR3c) detected by the third still image detection operation by M pixels in the column direction, and may set the remaining three detection areas DR1d, DR2d, DR3d, and DR4d of the four fourth detection areas DR1d, DR2d, DR3d, and DR4d having substantially the same size by equally dividing the motion image area reduced by M pixels. In the seventh and eighth frame periods FP7 and FP8 , the still image detection block 170 a may perform a fourth still image detection operation on each of the four fourth detection regions DR1 d , DR2 d , DR3 d , and DR4 d by using the four registers 161 , 162 , 163 , and 164 .

[0065] Gradually increasing the number of detection areas assigned to still image areas can be repeated until all detection areas are determined to be moving image areas. For example, when a still image area is detected through the fourth still image detection operation, the detection area setting block 171 can further increase the still image area detected through the fourth still image detection operation by M pixels in the column direction, set the still image area with the further M pixels increased as one of the four fifth detection areas, further reduce the moving image area detected through the fourth still image detection operation by M pixels in the column direction, and set the remaining three detection areas of the four fifth detection areas having substantially the same size by equally dividing the moving image area with the further M pixels decreased. The still image detection block 170a can perform the fifth still image detection operation on each of the fifth detection areas using the four registers 161, 162, 163, and 164.

[0066] In the case where all the detection areas (e.g., the four fifth detection areas) are determined as motion image areas by the current still image detection operation (e.g., the fifth still image detection operation), the still image detection block 170a may perform a subsequent still image detection operation by using the detection areas (e.g., the four fourth detection areas DR1d, DR2d, DR3d, and DR4d) used in the previous still image detection operation (e.g., the fourth still image detection operation). For example, in the case where all the fifth detection areas are determined as motion image areas by the fifth still image detection operation, in the subsequent frame period, the detection area setting block 171 may set the four fourth detection areas DR1d, DR2d, DR3d, and DR4d used in the fourth still image detection operation, and may continuously perform subsequent still image detection operations on the four fourth detection areas DR1d, DR2d, DR3d, and DR4d by using the four registers 161, 162, 163, and 164. In addition, the still image detection block 170a may continuously use the four fourth detection areas DR1d, DR2d, DR3d, and DR4d until the still image area (e.g., DR4d) detected by the subsequent still image detection operation changes. If the still image area (DR4d) detected by the subsequent still image detection operation changes, the still image detection block 170a may reset the four fourth detection areas DR1d, DR2d, DR3d, and DR4d and may reuse the four first detection areas DR1a, DR2a, DR3a, and DR4a into which the display panel 110a is equally divided.

[0067] In this manner, by dynamically setting or changing a plurality of detection areas respectively corresponding to the N registers 160 using results of previous still image detection operations, the panel driver 120 may not use a frame memory and may finely detect a still image area by using a limited number of registers 160 .

[0068] Refer again Figure 1 and Figure 2 The driving frequency determination block 180 may determine the driving frequency of the motion image area detected by the still image detection block 170 a as a normal driving frequency (e.g., approximately 120 Hz or approximately 60 Hz), and may determine the driving frequency of the still image area detected by the still image detection block 170 a as a low frequency lower than the normal driving frequency by using the flicker lookup table 190.

[0069] The flicker lookup table 190 may store a plurality of flicker values corresponding to a plurality of gray levels (e.g., 256 gray levels from gray level 0 to gray level 255). Here, the flicker value may represent the level of flicker perceived by the user. For example, Figure 7As shown, the flicker lookup table 190 may store one flicker value for every four gray levels, but the number of flicker values stored in the flicker lookup table 190 may not be limited to Figure 7 In the example, Figure 7 As shown, the flicker lookup table 190 may store a flicker value of 0 corresponding to a driving frequency of approximately 1 Hz with respect to gray levels 0 to 7, a flicker value of 40 corresponding to a driving frequency of approximately 2 Hz with respect to gray levels 8 to 11, a flicker value of 80 corresponding to a driving frequency of approximately 5 Hz with respect to gray levels 12 to 15, a flicker value of 120 corresponding to a driving frequency of approximately 10 Hz with respect to gray levels 16 to 19, a flicker value of 160 corresponding to a driving frequency of approximately 30 Hz with respect to gray levels 20 to 23, a flicker value of 200 corresponding to a driving frequency of approximately 60 Hz with respect to gray levels 24 to 27, and a flicker value of 0 corresponding to a driving frequency of approximately 1 Hz with respect to gray levels 236 to 255. However, the flicker values stored in the flicker lookup table 190 are not limited to Figure 7 .

[0070] like Figure 8 As shown, when the still image detection block 170a determines that the three detection areas DR1 to DR3 of the display panel 110e are moving image areas and the one detection area DR4 of the display panel 110e is a still image area, the driving frequency determination block 180 may determine the first driving frequency FF1 of the moving image area as a normal driving frequency, for example, approximately 120 Hz. Furthermore, the driving frequency determination block 180 may divide the still image area into first to twentieth segments SEG1 to SEG20, determine a plurality of segment flicker values corresponding to the grayscale levels of the image data of the first to twentieth segments SEG1 to SEG20 using the flicker lookup table 190, and determine a plurality of segment driving frequencies corresponding to the plurality of segment flicker values.

[0071] Figure 8 An example is shown in which segment driving frequencies of approximately 30 Hz, approximately 30 Hz, approximately 30 Hz, approximately 30 Hz, approximately 30 Hz, approximately 30 Hz, approximately 30 Hz, approximately 15 Hz, approximately 6 Hz, approximately 15 Hz, approximately 15 Hz, approximately 30 Hz, approximately 15 Hz, approximately 15 Hz, approximately 30 Hz, approximately 15 Hz, approximately 30 Hz, approximately 15 Hz, approximately 30 Hz, approximately 15 Hz, approximately 30 Hz, approximately 15 Hz, and approximately 30 Hz are determined with respect to the first segment SEG1 to the twentieth segment SEG20. In addition, the driving frequency decision block 180 may determine the second driving frequency FF2 of the still image area as the maximum frequency among the plurality of segment driving frequencies, for example, approximately 30 Hz.

[0072] The panel driver 120 may drive the motion image area of the display panel 110 at a first driving frequency FF1 or a normal driving frequency, and may drive the still image area of the display panel 110 at a second driving frequency FF2 or a low frequency lower than the normal driving frequency. Figure 9 As shown, when the first driving frequency FF1 is approximately 120 Hz and the second driving frequency FF2 is approximately 30 Hz, even if the controller 150 receives frame data FDACT for the entire area of the display panel 110 as input image data IDAT in each frame period FP, the controller 150 may output the first partial data PD1 for the moving image area and the second partial data PD2 for the still image area as output image data ODAT in one of four consecutive frame periods FP, but may output only the first partial data PD1 for the moving image area as output image data ODAT in three of the four consecutive frame periods FP. Therefore, the data driver 130 may provide the data signal DS to the moving image area in each frame period FP, but may only provide the data signal DS to the still image area in one of the four consecutive frame periods FP. Therefore, the moving image area may be driven at the first driving frequency FF1 of approximately 120 Hz, and the still image area may be driven at the second driving frequency FF2 of approximately 30 Hz.

[0073] Figure 10 is a flowchart illustrating a method of detecting a still image in the display apparatus 100 according to an exemplary embodiment of the inventive concept.

[0074] Reference Figure 1 and Figure 10 In a method for detecting a still image in a display device 100 including N registers 160, the panel driver 120 may divide the display panel 110 into N first detection areas (S310). For example, in a first frame period and a second frame period, the panel driver 120 may equally divide the input image data IDAT for the display panel 110 into N first detection area image data having substantially the same size for the first detection areas.

[0075] The panel driver 120 may perform a first still image detection operation on each of the plurality of first detection areas by using the N registers 160 (S315). For example, in a first frame period, the panel driver 120 may calculate a previous representative value of the image data of the first detection areas, and may store the previous representative value in the N registers 160. In addition, in a second frame period, the panel driver 120 may calculate a current representative value of the image data of the first detection areas, and may perform the first still image detection operation to determine whether each of the plurality of first detection areas is a still image area or a moving image area by comparing the current representative value with the previous representative value stored in the N registers 160.

[0076] The panel driver 120 may divide the display panel 110 into N second detection areas different from the first detection area by using the result of the first still image detection operation (S320). For example, in the third frame period and the fourth frame period, the panel driver 120 may set the still image area detected by the first still image detection operation as one of the plurality of second detection areas, may set the remaining N-1 detection areas of the plurality of second detection areas having substantially the same size by equally dividing the moving image area detected by the first still image detection operation, and may divide the input image data IDAT for the display panel 110 into N second detection area image data for the plurality of second detection areas.

[0077] The panel driver 120 may perform a second still image detection operation on each of the plurality of second detection areas by using the N registers 160 (S325). For example, in the third frame period, the panel driver 120 may calculate a previous representative value of the second detection area image data and may store the previous representative value in the N registers 160. In addition, in the fourth frame period, the panel driver 120 may calculate a current representative value of the second detection area image data and may perform a second still image detection operation to determine whether each of the plurality of second detection areas is a still image area or a moving image area by comparing the current representative value with the previous representative value stored in the N registers 160.

[0078] In the case where the previous still image area detected by the previous still image detection operation and the current still image area detected by the current still image detection operation are different from each other (S330: No), the panel driver 120 may change the second detection area by using the result of the current still image detection operation (S320), and may perform the still image detection operation (S325) on each of the changed second detection areas by using the N registers 160. For example, in the case where the still image area detected by the first still image detection operation and the still image area detected by the second still image detection operation are different from each other, the panel driver 120 may set the still image area detected by the second still image detection operation as one of the N third detection areas, set the remaining N-1 detection areas of the plurality of third detection areas having substantially the same size by equally dividing the moving image area detected by the second still image detection operation, and may perform the third still image detection operation on each of the plurality of third detection areas by using the N registers 160.

[0079] Alternatively, in a case where a previous still image area detected by a previous still image detection operation and a current still image area detected by a current still image detection operation are substantially identical to each other (S330: Yes), the panel driver 120 may set N third detection areas by increasing the current still image area detected by the current still image detection operation and by decreasing the current moving image area detected by the current still image detection operation (S340), and may perform a still image detection operation on each of the plurality of third detection areas by using N registers 160 (S345).

[0080] For example, in a case where the still image area detected by the first still image detection operation and the still image area detected by the second still image detection operation are substantially the same as each other, the panel driver 120 may increase the still image area detected by the second still image detection operation by M pixels in the column direction, where M is an integer greater than 0, may set the still image area with the increased M pixels as one of the N third detection areas, may reduce the motion image area detected by the second still image detection operation by M pixels in the column direction, may set the remaining N-1 detection areas of the N third detection areas having substantially the same size by equally dividing the motion image area with the reduced M pixels, and may perform the third still image detection operation on each of the N third detection areas by using N registers 160.

[0081] In the case where a still image area is detected through the third still image detection operation (S350: No), the panel driver 120 may further increase the still image area detected through the third still image detection operation by M pixels in the column direction, may set the still image area further increased by M pixels as one of the N third detection areas, may further reduce the motion image area detected through the third still image detection operation by M pixels in the column direction, may set the remaining N-1 detection areas of the N third detection areas having substantially the same size by equally dividing the motion image area further reduced by M pixels, and may perform a still image detection operation on each of the N third detection areas by using N registers 160.

[0082] Alternatively, if all third detection areas are determined to be moving image areas (S350: Yes), the panel driver 120 may set the detection area used in the previous still image detection operation (e.g., the second detection area used in the second image detection operation) as N fourth detection areas (S360), and may perform a fourth still image detection operation (S365) on each of the N fourth detection areas by using the N registers 160. The fourth still image detection operation (S365) may be continuously performed on each of the N fourth detection areas until the still image area detected by the fourth still image detection operation is changed (S370: No). If the still image area detected by the fourth still image detection operation is changed (S370: Yes), the fourth detection area may be reset, and the method may be performed again from the initial operation (S310).

[0083] As described above, in a method of detecting a still image in the display device 100 according to an exemplary embodiment of the present inventive concept, the detection areas respectively corresponding to the N registers 160 can be dynamically set or changed by using the result of a previous still image detection operation. Therefore, the panel driver 120 may not use a frame memory and may finely detect a still image area by using a limited number of registers 160.

[0084] Figure 11 is a block diagram illustrating an electronic device 1100 including a display device according to an exemplary embodiment of the inventive concept.

[0085] Reference Figure 11The electronic device 1100 may include a processor 1110, a memory device 1120, a storage device 1130, an input / output (I / O) device 1140, a power supply 1150, and a display device 1160. The electronic device 1100 may also include multiple ports for communicating with a video card, a sound card, a memory card, a Universal Serial Bus (USB) device, other electronic devices, and the like.

[0086] The processor 1110 may perform various computing functions or tasks. The processor 1110 may be an application processor (AP), a microprocessor, a central processing unit (CPU), or the like. The processor 1110 may be coupled to other components via an address bus, a control bus, a data bus, or the like. In addition, in an exemplary embodiment of the present inventive concept, the processor 1110 may be further coupled to an expansion bus such as a peripheral component interconnect (PCI) bus.

[0087] The memory device 1120 may store data used for the operation of the electronic device 1100 . For example, the memory device 1120 may include: at least one non-volatile memory device, such as an Erasable Programmable Read-Only Memory (EPROM) device, an Electrically Erasable Programmable Read-Only Memory (EEPROM) device, a Flash memory device, a Phase Change Random Access Memory (PRAM) device, a Resistance Random Access Memory (RRAM) device, a Nano Floating Gate Memory (NFGM) device, a Polymer Random Access Memory (PoRAM) device, a Magnetic Random Access Memory (MRAM) device, a Ferroelectric Random Access Memory (FRAM) device, etc.; and / or at least one volatile memory device, such as a Dynamic Random Access Memory (DRAM) device, a Static Random Access Memory (SRAM) device, etc. Memory, SRAM) devices, mobile dynamic random access memory (mobile DRAM) devices, etc.

[0088] The storage device 1130 may be a solid-state drive (SSD), a hard disk drive (HDD), a CD-ROM, or the like. The I / O device 1140 may be an input device such as a keyboard, a keypad, a mouse, a touch screen, or the like, as well as an output device such as a printer or a speaker. The power supply 1150 may provide power for the operation of the electronic device 1100. The display device 1160 may be coupled to other components via a bus or other communication link.

[0089] The display device 1160 can divide the display panel into N first detection areas, perform a first still image detection operation on each of the N first detection areas by using N registers, divide the display panel into N second detection areas different from the first detection areas by using the results of the first still image detection operation, and perform a second still image detection operation on each of the N second detection areas by using the N registers. Therefore, the display device 1160 according to an exemplary embodiment of the present inventive concept can detect still image areas in detail without using a frame memory and by using a limited number of registers.

[0090] The present invention can be applied to any display device and any electronic device including the display device. For example, the present invention can be applied to mobile phones, smart phones, wearable electronic devices, tablet computers, televisions (TVs), digital TVs, 3D TVs, personal computers (PCs), home appliances, notebook computers, personal digital assistants (PDAs), portable multimedia players (PMPs), digital cameras, music players, portable game consoles, navigation devices, and the like.

[0091] As described above, a display device and a method for detecting a still image in a display device according to an exemplary embodiment of the present inventive concept can divide a display panel into N first detection areas, perform a first still image detection operation on each of the N first detection areas by using N registers, divide the display panel into N second detection areas different from the first detection areas by using the results of the first still image detection operation, and perform a second still image detection operation on each of the N second detection areas by using the N registers. Therefore, a display device according to an exemplary embodiment of the present inventive concept can detect still image areas in detail without using a frame memory and by using a limited number of registers.

[0092] While the present invention has been shown and described with reference to exemplary embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as set forth in the appended claims.

Claims

1. A display device comprising: a display panel comprising a plurality of pixels; as well as The panel driver includes N registers, Where N is an integer greater than 1, and The panel driver is configured to: divide the display panel into N first detection areas; perform a first still image detection operation to determine whether each of the N first detection areas is a still image area or a moving image area by comparing a previous representative value of the N first detection area image data for the N first detection areas in a first frame period with a current representative value in a second frame period by using the N registers; divide the display panel into N second detection areas different from the N first detection areas by using a result of the first still image detection operation, wherein the still image area detected by the first still image detection operation is set as one of the N second detection areas, and the moving image area detected by the first still image detection operation is set as the remaining N-1 detection areas of the N second detection areas; and perform a second still image detection operation to determine whether each of the N second detection areas is a still image area or a moving image area by comparing a previous representative value of the N second detection area image data for the N second detection areas in a third frame period with a current representative value in a fourth frame period by using the N registers.

2. The display device according to claim 1, wherein The panel driver equally divides input image data for the display panel into the N first detection area image data having the same size for the N first detection areas in the first frame period and the second frame period.

3. The display device according to claim 2, wherein: In the first frame period, the panel driver calculates the previous representative values of the N first detection area image data and stores the previous representative values in the N registers, and In the second frame period, the panel driver calculates the current representative values of the N first detection area image data and performs the first still image detection operation by comparing the current representative values with the previous representative values stored in the N registers.

4. The display device according to claim 3, wherein Each of the previous representative value and the current representative value is a checksum value of a corresponding one of the N first detection area image data.

5. The display device according to claim 3, wherein Each of the previous representative value and the current representative value is an average value of a corresponding one of the N first detection area image data. The display device according to claim 3 , wherein: Each of the previous representative value and the current representative value is a sum value of a corresponding one of the N first detection area image data.

7. The display device according to claim 1, wherein In the third frame period and the fourth frame period, the panel driver sets the still image area detected by the first still image detection operation as one of the N second detection areas, sets the remaining N-1 detection areas of the N second detection areas with the same size by equally dividing the moving image area detected by the first still image detection operation, and divides the input image data for the display panel into the N second detection area image data for the N second detection areas.

8. The display device according to claim 7, wherein: In the third frame period, the panel driver calculates the previous representative values of the N second detection area image data and stores the previous representative values in the N registers, and In the fourth frame period, the panel driver calculates the current representative values of the N second detection area image data and performs the second still image detection operation by comparing the current representative values with the previous representative values stored in the N registers.

9. A method for detecting a still image in a display device, the display device comprising N registers, wherein: N is an integer greater than 1, and the method comprises: Dividing the display panel of the display device into N first detection areas; performing a first still image detection operation of determining whether each of the N first detection areas is a still image area or a moving image area by comparing a previous representative value of N first detection area image data for the N first detection areas in a first frame period with a current representative value in a second frame period using the N registers; dividing the display panel into N second detection areas different from the N first detection areas by using a result of the first still image detection operation, wherein the still image area detected by the first still image detection operation is set as one of the N second detection areas, and the moving image area detected by the first still image detection operation is set as the remaining N-1 detection areas of the N second detection areas; and A second still image detection operation is performed to determine whether each of the N second detection areas is a still image area or a moving image area by using the N registers to compare the previous representative value of the N second detection area image data for the N second detection areas in the third frame period with the current representative value in the fourth frame period.

10. A method for detecting a still image in a display device, the method comprising: In a first frame period and a second frame period, the display panel of the display device is evenly divided into N first detection areas, and the input image data is evenly divided into N first detection area image data, where N is an integer greater than 1; In the first frame period, storing previous representative values of the N first detection area image data; in the second frame period, calculating a current representative value of the N first detection area image data, and performing a first still image detection operation by comparing the current representative value with the previous representative value to determine whether each of the N first detection areas is a still image area or a moving image area; In a third frame period and a fourth frame period, at least two of the still image areas in the N first detection areas are set as one detection area of the N second detection areas, and the remaining portion of the N first detection areas is equally divided into the remaining N-1 detection areas of the N second detection areas; and In the fourth frame period, a second still image detection operation is performed by comparing the previous representative value of the N second detection area image data for the N second detection areas in the third frame period with the current representative value in the fourth frame period to determine whether each of the N second detection areas is a still image area or a moving image area.

Images