Patent Publication Number: US-9842534-B2

Title: Display device and display system including the same

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     Korean Patent Application No. 10-2014-0121805, filed on Sep. 15, 2014, and entitled, “Display Device and Display System Including the Same,” is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     One or more embodiments described herein relate to a display device and a display system including the display device. 
     2. Description of the Related Art 
     As the radiation time of an organic light-emitting diode increases, its luminous efficiency may decrease. Also, the more an organic light-emitting diode is used, the more likely an after-image effect may be generated in a display panel. 
     SUMMARY 
     In accordance with one embodiment, a display device includes a controller to generate an image control signal and a position control signal; an image processor to generate a frame image based on an image signal and the image control signal, and to provide the frame image and the position control signal, the position control signal including a position information where the frame image is located; and a pixel array including base pixels and addition pixels, the pixel array to display the frame image in the base pixels and the addition pixels based on the position control signal, wherein a number of the base pixels corresponds to a resolution of the frame image and wherein the addition pixels are different from the base pixels. 
     The addition pixels may be at first to fourth sides of the base pixels. A number of first direction addition pixels added to the first side according to a first direction may be equal to a number of a third direction addition pixels added to the third side according to a third direction, and a number of a second direction addition pixels added to the second side according to a second direction may be equal to a number of a fourth direction addition pixels added to the fourth side according to a fourth direction. 
     A proportion of the number of the first direction addition pixels and the number of the second direction addition pixels may be 16:9. A number of a first direction addition pixels added to the first side according to a first direction may be different from a number of a third direction addition pixels added to the third side according to a third direction, and a number of a second direction addition pixels added to the second side according to a second direction may be different from a number of a fourth direction addition pixels added to the fourth side according to a fourth direction. 
     A proportion of a first addition pixel sum and a second addition pixel sum may be 16:9, the first addition pixel sum may be a sum of the number of the first direction addition pixels and the number of the third direction addition pixels, and the second addition pixel sum may be a sum of the number of the second direction addition pixels and the number of the fourth direction addition pixels. 
     The addition pixels may be at one side of a first side or a third side of the base pixels, and the addition pixels may be at one side of a second side or a fourth side of the base pixels. When the addition pixels are at the first side and the second side, a proportion of a number of a first direction addition pixels and a number of a second direction addition pixels may be 16:9, the number of first direction addition pixels may be added to the first side according to a first direction, and the number of a second direction addition pixels may be added to the second side according to a second direction. 
     A number of the addition pixels may be less than a number of the base pixels. The number of the addition pixels may be less than 3% of the number of the base pixels. The pixel array may display the frame image in a plurality of pixels in the base pixels and the addition pixels, a number of the plurality of pixels may correspond to a resolution of the frame image, and a level value of pixels that do not display the frame image among the base pixels and the addition pixels may be one of a first level value or a second level value. A color corresponding to the first level value may be black, and a color corresponding to the second level value may be gray. 
     The controller may generate a background control signal, the image processor may output the background control signal, the frame image, and the position control signal, and the pixel array may select one of the first level value or the second level value as the level value of pixels that do not display the frame image, among the base pixels and the addition pixels, based on the background control signal. 
     The position information may be changed based on a predetermined time interval. The predetermined time interval may be less than three seconds. When the controller provides a first position control signal and provides a second control signal after the predetermined time interval, second position information in the second position control signal may include information corresponding to an adjacent pixel of a pixel indicated by a first position information in the first position control signal. 
     In accordance with another embodiment, a display system includes a processor to provide an image signal; and a display device to display a frame image generated based on the image signal, the display device including: a controller to generate an image control signal and a position control signal; an image processor to generate a frame image based on an image signal and the image control signal, and to provide the frame image and the position control signal, the position control signal including position information where the frame image is located; and a pixel array including base pixels and addition pixels, the pixel array to display the frame image in the base pixels and the addition pixels based on the position control signal, wherein a number of the base pixels corresponds to a resolution of the frame image and wherein the addition pixels are different from the base pixels. 
     The position information may be changed every predetermined time interval, and the controller may provide the position control signal to the image processing unit the every predetermined time interval. When the position information in the position control signal is changed, a location where the frame image is displayed in the pixel array may be changed. The addition pixels may be at first to fourth sides of the base pixels, a number of a first direction addition pixels added to the first side according to a first direction may be equal to a number of a third direction addition pixels added to the third side according to a third direction, and a number of a second direction addition pixels added to the second side according to a second direction may be equal to a number of a fourth direction addition pixels added to the fourth side according to a fourth direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features will become apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which: 
         FIG. 1  illustrates an embodiment of a display device; 
         FIG. 2  illustrates an embodiment of a pixel array; 
         FIG. 3  illustrates an embodiment of base pixels in the pixel array; 
         FIG. 4  illustrates an embodiment of addition pixels in the pixel array; 
         FIG. 5  illustrates another embodiment of a pixel array; 
         FIG. 6  illustrates another embodiment of addition pixels; 
         FIGS. 7 and 8  illustrate additional embodiments of a pixel array; 
         FIG. 9  illustrates an embodiment of base pixels and addition pixels; 
         FIGS. 10 to 12  illustrate operation of the display device of  FIG. 1  according to one embodiment; 
         FIGS. 13 to 17  illustrate accumulation brightness based on background color according to one embodiment; and 
         FIG. 18  illustrates another embodiment a display device; 
         FIG. 19  illustrates position information changed every predetermined time interval according to one embodiment; 
         FIG. 20  illustrates a region where a frame image is displayed based on position information according to one embodiment; 
         FIG. 21  illustrates an embodiment of a display system; 
         FIG. 22  illustrates a position control signal changed every predetermined time interval according to one embodiment; and 
         FIG. 23  illustrates an embodiment of a mobile device. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments are described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art. In the drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout. 
       FIG. 1  illustrates an embodiment of a display device  10 , and  FIG. 2  illustrates an embodiment of a pixel array in the display device  10 . Referring to  FIGS. 1 and 2 , the display device  10  includes a control unit  300 , an image processing unit  100 , and a pixel array  500 . The control unit  300  generates an image control signal ICS and a position control signal PCS. The image control signal ICS may be used to compose a frame image FI from an image signal. The position control signal PCS may be used to determine a position where the frame image FI is displayed in the pixel array  500 . 
     The image processing unit  100  generates a frame image FI based on an image signal IS and the image control signal ICS. The image processing unit  100  provides the frame image FI and the position control signal PCS. The position control signal PCS includes position information PI where the frame image FI is located. For example, at a first time, the image processing unit  100  may provide the first frame image FI 1  and the first position control signal PCS 1  to the pixel array  500 . The first frame image FI 1  may be generated based on the image signal IS and the image control signal ICS. The first position control signal PCS 1  may include the position information PI where the first frame image FI 1  is located. 
     At a second time after the first time, the image processing unit  100  may provide the second frame image FI 2  and the second position control signal PCS 2  to the pixel array  500 . The second frame image FI 2  may be generated based on the image signal IS and the image control signal ICS. The second position control signal PCS 2  may include the position information PI where the second frame image FI 2  is located. A pixel corresponding to the position information PI in the second position control signal PCS 2  may be an adjacent pixel to a pixel corresponding to the position information PI in the first position control signal PCS 1 . 
     The pixel array  500  includes base pixels  510  and addition pixels  530 . The pixel array  500  displays the frame image FI in the base pixels  510  and the addition pixels  530  based on the position control signal PCS. A number of the base pixels  510  correspond to a resolution of the frame image FI. For example, the resolution of the frame image FI may be 3840*2160. If the frame image FI has this resolution, the number of the base pixels  510  may be 3840*2160. The addition pixels  530  are different from the base pixels  510 . The addition pixels  530  may be located at one or more sides of the base pixels  510 . In one embodiment, the addition pixels  530  are located at first to fourth sides SIDE 1  to SIDE 4  of the base pixels  510 . 
     For example, the pixel array  500  may display the first frame image FI 1  in the base pixels  510  based on the first position control signal PCS 1 . The first frame image FI 1  may be generated based on the image signal IS and the image control signal ICS. After that, the pixel array  500  may display the second frame image FI 2  in pixels that are one pixel-shifted from the base pixels  510  based on the second position control signal PCS 2 . 
     The second frame image FI 2  may be generated based on the image signal IS and the image control signal ICS. For example, the position information PI in the second position control signal PCS 2  may be a first position information PI 1 . The first position information PI 1  may indicate a one pixel-shift according to the first direction D 1 . The pixel array  500  may display the second frame image FI 2  in pixels that are one pixel-shifted from the base pixels  510  according to the first direction D 1 . In this case, the second frame image FI 2  may be displayed in the base pixels  510  and addition pixels  530 . 
     Also, the position information PI in the second position control signal PCS 2  may be a second position information PI 2 . The second position information PI 2  may indicate one pixel-shift according to the second direction D 2 . The pixel array  500  may display the second frame image FI 2  in pixels that are one pixel-shifted from the base pixels  510  according to the second direction D 2 . In this case, the second frame image FI 2  may be displayed in the base pixels  510  and the addition pixels  530 . In the same manner, the pixel array  500  may display the second frame image FI 2  in pixels that are one pixel-shifted from the base pixels  510  according to the third direction D 3 . Also, the pixel array  500  may display the second frame image FI 2  in pixels that are one pixel-shifted from the base pixels  510  according to the fourth direction D 4 . 
     In one embodiment, a number APN 1  of a first direction addition pixels added to the first side SIDE 1  according to a first direction D 1  may be equal to a number APN 3  of a third direction addition pixels added to the third side SIDE 3  according to a third direction D 3 . A number APN 2  of a second direction addition pixels added to the second side SIDE 2  according to a second direction D 2  may be equal to a number APN 4  of a fourth direction addition pixels added to the fourth side SIDE 4  according to a fourth direction D 4 . 
     For example, the number APN 1  of the first direction addition pixels added to the first side SIDE 1  according to the first direction D 1  may be 5. The number APN 3  of the third direction addition pixels added to the third side SIDE 3  according to the third direction D 3  may be 5. In this case, the number APN 1  of the first direction addition pixels and the number APN 3  of the third direction addition pixels may be the same number  5 . 
     The number APN 2  of the second direction addition pixels added to the second side SIDE 2  according to the second direction D 2  may be 4. The number APN 4  of the fourth direction addition pixels added to the fourth side SIDE 4  according to the fourth direction D 4  may be 4. In this case, the number APN 2  of the second direction addition pixels and the number APN 4  of the fourth direction addition pixels may be the same number  4 . In case the addition pixels  530  are located in a first to fourth side SIDE 1  to SIDE 4  of the base pixels  510 , the number APN 1  of the first direction addition pixels and the number APN 3  of the third direction addition pixels may be equal. The number APN 2  of the second direction addition pixels and the number APN 4  of the fourth direction addition pixels may be equal. 
     In accordance with the present embodiment, changing where the frame image FI is displayed using the addition pixels  530  in the display device  10  may reduce or prevent distortion of the frame image FI because the resolution of the frame image FI is maintained. Also, changing the position where the frame image FI is displayed using the addition pixels  530  may reduce or prevent an after-image effect. 
       FIG. 3  illustrates an embodiment of base pixels in the pixel array  500  of  FIG. 2 , and  FIG. 4  illustrates addition pixels  530  in the pixel array  500  of  FIG. 2  according to one embodiment. 
     Referring to  FIGS. 3 and 4 , the pixel array  500  may include the base pixels  510  and the addition pixels  530 . The number of the base pixels  510  may correspond to the resolution of the frame image FI. For example, the resolution of the frame image FI may be 3840*2160. In this case, the number of the base pixels  510  may be 3840*2160. The addition pixels  530  are different from the base pixels  510 . The addition pixels  530  may be located at one or more sides of the base pixels  510 . In one embodiment, the additional pixels  530  are located at first to fourth sides SIDE 1  to SIDE 4  of the base pixels  510 . 
     For example, the number of pixels corresponding to the first side SIDE 1  of the base pixels  510  may be 9*N. The number of pixels corresponding to the fourth side SIDE 4  of the base pixels  510  may be 16*N. The proportion of the number of pixels corresponding to the first side SIDE 1  of the base pixels  510  and the number of pixels corresponding to the fourth side SIDE 4  of the base pixels  510  may be 16:9. In this case, the proportion of the number APN 1  of the first direction addition pixels and the number APN 2  of the second direction addition pixels may be 16:9. 
     For example, the number APN 1  of the first direction addition pixels may be 16. The number APN 2  of the second direction addition pixels may be 9. If the proportion of the number APN 1  of the first direction addition pixels and the number APN 2  of the second direction addition pixels is 16:9, in the case where the frame image FI is extended in pixel array  500 , distortion of the frame image FI may be reduced or prevented because the proportion of the frame image FI that is 16:9 is maintained. 
       FIG. 5  illustrates another embodiment of a pixel array  500  in the display device of  FIG. 1 . Referring to  FIG. 5 , the pixel array  500  may include the base pixels  510  and the addition pixels  530 . A number APN 1  of a first direction addition pixels added to the first side SIDE 1  according to a first direction D 1  may be different from a number APN 3  of a third direction addition pixels added to the third side SIDE 3  according to a third direction D 3 . For example, the number APN 1  of the first direction addition pixels may be 2. The number APN 3  of the third direction addition pixels may be 8. The base pixels  510  may not be located in the center of the pixel array  500 . In case the base pixels  510  are not located in the center of the pixel array  500 , the number APN 1  of the first direction addition pixels added to the first side SIDE 1  according to the first direction D 1  may be different from the number APN 3  of the third direction addition pixels added to the third side SIDE 3  according to the third direction D 3 . 
     A number APN 2  of a second direction addition pixels added to the second side SIDE 2  according to a second direction D 2  may be different from a number APN 4  of a fourth direction addition pixels added to the fourth side SIDE 4  according to a fourth direction D 4 . For example, the number APN 2  of the second direction addition pixels may be 2. The number APN 4  of the fourth direction addition pixels may be 6. The base pixels  510  may not be located in the center of the pixel array  500 . In case the base pixels  510  are not located in the center of the pixel array  500 , the number APN 2  of the second direction addition pixels added to the second side SIDE 2  according to the second direction D 2  may be different from the number APN 4  of the fourth direction addition pixels added to the fourth side SIDE 4  according to the fourth direction D 4 . 
       FIG. 6  illustrates an embodiment of addition pixels in the pixel array  500  of  FIG. 5 . Referring to  FIG. 6 , the pixel array  500  includes the base pixels  510  and the addition pixels  530 . The number of pixels corresponding to the first side SIDE 1  of the base pixels  510  are 9*N. The number of pixels corresponding to the fourth side SIDE 4  of the base pixels  510  are 16*N. 
     The proportion of the number of pixels corresponding to the first side SIDE 1  of the base pixels  510  and the number of pixels corresponding to the fourth side SIDE 4  of the base pixels  510  may be 16:9. In this case, the proportion of a first addition pixel sum and a second addition pixel sum may be 16:9. The first addition pixel sum may be a sum of the number APN 1  of the first direction addition pixels and the number APN 3  of the third direction addition pixels. The second addition pixel sum may be a sum of the number APN 2  of the second direction addition pixels and the number APN 4  of the fourth direction addition pixels. 
     For example, the number APN 1  of the first direction addition pixels may be 2. The number APN 3  of the third direction addition pixels may be 14. The first addition pixel sum may be 16. The number APN 2  of the second direction addition pixels may be 2. The number APN 4  of the fourth direction addition pixels may be 7. The second addition pixel sum may be 9. The proportion of the first addition pixel sum and the second addition pixel sum may be 16:9. If the proportion of the first addition pixel sum and the second addition pixel sum is 16:9, in case the frame image FI is extended in pixel array  500 , the distortion of the frame image FI may be reduced or prevented because the proportion of the frame image FI that is 16:9 is maintained. 
       FIGS. 7 and 8  illustrate another example of a pixel array  500  in the display device of  FIG. 1 . Referring to  FIGS. 7 and 8 , the pixel array  500  may include the base pixels  510  and the addition pixels  530 . The addition pixels  530  may be located in one side of a first side SIDE 1  and a third side SIDE 3  of the base pixels  510 . The addition pixels  530  may be located in one side of a second side SIDE 2  and a fourth side SIDE 4  of the base pixels  510 . For example, the addition pixels  530  may be located at the first side SIDE 1  and the second side SIDE 2  only. Also, the addition pixels  530  may be located at the third side SIDE 3  and the fourth side SIDE 4  only. Also, the addition pixels  530  may be located at the first side SIDE 1  and the fourth side only. Also, the addition pixels  530  may be located at the second side SIDE 2  and the third side SIDE 3  only. 
     In one embodiment, in case the one side of the first side SIDE 1  and the third side SIDE 3  is the first side SIDE 1  and the one side of the second side SIDE 2  and the fourth side SIDE 4  is the second side SIDE 2 , the proportion of a number APN 1  of a first direction addition pixels and a number APN 2  of a second direction addition pixels may be 16:9. 
     The number APN 1  of the first direction addition pixels may be added to the first side SIDE 1  according to a first direction D 1 . The number APN 2  of the second direction addition pixels may be added to the second side SIDE 2  according to a second direction D 2 . For example, the number APN 1  of the first direction addition pixels may be 16. The number APN 2  of the second direction addition pixels may be 9. The base pixels  510  may not be located in the center of the pixel array  500 . The base pixels  510  may be located in edges of the pixel array  500 . In case the one side of the first side SIDE 1  and the third side SIDE 3  is the first side SIDE 1  and the one side of the second side SIDE 2  and the fourth side SIDE 4  is the second side SIDE 2 , the proportion of the number APN 1  of the first direction addition pixels and the number APN 2  of the second direction addition pixels may be 16:9. 
     In one embodiment, in case the one side of the first side SIDE 1  and the third side SIDE 3  is the third side SIDE 3  and the one side of the second side SIDE 2  and the fourth side SIDE 4  is the fourth side SIDE 4 , the proportion of the number APN 3  of the third direction addition pixels and the number APN 4  of the fourth direction addition pixels may be 16:9. The number APN 3  of the third direction addition pixels may be added to the third side SIDE 3  according to a third direction D 3 . The number APN 4  of the fourth direction addition pixels may be added to the fourth side SIDE 4  according to a fourth direction D 4 . For example, the number APN 3  of the third direction addition pixels may be 16. The number APN 4  of the fourth direction addition pixels may be 9. 
     The base pixels  510  may not be located at the center of the pixel array  500 . The base pixels  510  may be located at edges of the pixel array  500 . In case the one side of the first side SIDE 1  and the third side SIDE 3  is the third side SIDE 3  and the one side of the second side SIDE 2  and the fourth side SIDE 4  is the fourth side SIDE 4 , the proportion of the number APN 3  of the third direction addition pixels and the number APN 4  of the fourth direction addition pixels may be 16:9. 
       FIG. 9  illustrates another embodiment of base pixels  510  and addition pixels in the display device of  FIG. 1 . Referring to  FIG. 9 , the pixel array  500  may include the base pixels  510  and the addition pixels  530 . In  FIGS. 7 and 8 , the size of the base pixels  510  is illustrated to be very small for purposes of describing the addition pixels  530 . However, actually, most of the pixel array  500  may be the base pixels  510 . For example, the number of the base pixels  510  may be 3840*2160. The number APN 1  of the first direction addition pixels may be 16 and the number APN 2  of the second direction addition pixels may be 9. The number APN 3  of the third direction addition pixels may be 16 and the number APN 4  of the fourth direction addition pixels may be 9. Therefore, the number of the addition pixels  530  may be less than the number of base pixels  510 . 
     In one embodiment, the number of the addition pixels  530  may be less than 3% of the number of the base pixels  510 . For example, the number of the base pixels  510  may be 3840*2160. A certain percentage (e.g., 3%) of the number of the base pixels  510  may be about 240000 pixels. Therefore, in case the number of the base pixels  510  is 3840*2160, the number of the addition pixels  530  may be less than 240000 pixels 
       FIGS. 10 to 12  illustrate an embodiment for describing operation of the display device of  FIG. 1 . Referring to  FIGS. 10 to 12 , the pixel array  500  may include the base pixels  510  and the addition pixels  530 . For example, the pixel array  500  may display the first frame image FI 1  in the base pixels  510  based on the first position control signal PCS 1 . The first frame image FI 1  may be generated based on the image signal IS and the image control signal ICS. 
     Thereafter, the pixel array  500  may display the second frame image FI 2  in pixels that are one pixel-shifted from the base pixels  510  based on the second position control signal PCS 2 . The second frame image FI 2  may be generated based on the image signal IS and the image control signal ICS. 
     Thereafter, the pixel array  500  may display the third frame image FI 3  in pixels that are one pixel-shifted from the pixels where the second frame image FI 2  is displayed based on the second position control signal PCS 2 . The third frame image FI 3  may be generated based on the image signal IS and the image control signal ICS. 
     For example, the position information PI in the second position control signal PCS 2  may be the first position information PI 1 . The first position information PI 1  may indicate one pixel-shift according to the first direction D 1 . The pixel array  500  may display the second frame image FI 2  in pixels that are one pixel-shifted from the base pixels  510  according to the first direction D 1 . In this case, the second frame image FI 2  may be displayed in the base pixels  510  and the addition pixels  530 . The position information PI in the third position control signal PCS 3  may be the second position information PI 2 . The second position information PI 2  may indicate one pixel-shift according to the second direction D 2 . The pixel array  500  may display the third frame image FI 3  in pixels that are one pixel-shifted from the pixels that the second frame image FI 2  is displayed according to the second direction D 2 . In this case, the third frame image FI 3  may be displayed in the base pixels  510  and the addition pixels  530 . 
     The pixel array  500  may display the frame image FI in a plurality of pixels included in the base pixels  510  and the addition pixels  530 . The number of the plurality of pixels may correspond to a resolution of the frame image FI. A level value of pixels that do not display the frame image FI among the base pixels  510  and the addition pixels  530  may be one of a first level value and a second level value. For example, in  FIG. 10 , the level value of pixels that do not display the first frame image FI 1  among the base pixels  510  and the addition pixels  530  may be one of the first level value and the second level value. 
     In one embodiment, the color corresponding to the first level value may be black and the color corresponding to the second level value may be gray. For example, in  FIG. 10 , the level value of pixels that do not display the first frame image FI 1 , among the base pixels  510  and the addition pixels  530 , may be the first level value. In case the level value of pixels that do not display the first frame image FI 1  is the first level value, the color corresponding to pixels that do not display the first frame image FI 1  may be black. For example, in  FIG. 10 , the level value of pixels that do not display the first frame image FI 1  among the base pixels  510  and the addition pixels  530  may be the second level value. In case the level value of pixels that do not display the first frame image FI 1  is the second level value, the color corresponding to pixels that do not display the first frame image FI 1  may be gray. 
       FIGS. 13 to 17  illustrate an embodiment for describing accumulation brightness according to background color. Referring to  FIGS. 13 and 14 , the pixel array  500  may include the base pixels  510  and the addition pixels  530 . The addition pixels  530  may include the first addition pixels  530  and the second addition pixels  530 . The white area may be moved according to the first direction D 1  and the third direction D 3 . 
     During the first time interval, the white area may be moved according to the third direction D 3 . If the white area is moved according to the third direction D 3  during the first time interval, an X position corresponding to the position on the x-axis may be increased. 
     During the second time interval, the white area may be moved according to the first direction D 1 . If the white area is moved according to the first direction D 1  during the second time interval, the X position corresponding to the position on the x-axis may be decreased. 
     During the third time interval, the white area may be moved according to the first direction D 1 . If the white area is moved according to the first direction D 1  during the third time interval, the X position corresponding to the position on the x-axis may be decreased more. 
     During the fourth time interval, the white area may be moved according to the third direction D 3 . If the white area is moved according to the third direction D 3  during the fourth time interval, the X position corresponding to the position on the x-axis may be increased. 
     Referring to  FIG. 15 , the movement speed of the white area may be constant velocity. In case the white area is moved according to the third direction D 3 , the movement speed of the white area may be a positive number. In case the white area is moved according to the first direction D 1 , the movement speed of the white area may be a negative number. During the first time interval, the white area may be moved with a first velocity according to the third direction D 3 . During the second time interval, the white area may be moved with a second velocity according to the first direction D 1 . During the third time interval, the white area may be moved with the second velocity according to the first direction D 1 . During the fourth time interval, the white area may be moved with the first velocity according to the third direction D 3 . The first velocity may be the positive number and the second velocity may be the negative number. 
     The accumulation brightness of pixels located according to the x-axis may be illustrated as in  FIGS. 16 and 17 . The level value of pixels that do not display the frame image FI among the base pixels  510  and the addition pixels  530  may be one of the first level value and the second level value. The color corresponding to the first level value may be black and the color corresponding to the second level value may be gray. 
     In case the level value of pixels that do not display the first frame image FI 1  is the first level value corresponding to black, the deviation of the accumulation brightness between the pixels located in the center of the pixel array  500  and the pixels located at the edge of the pixel array  500  may be large. 
     In case the level value of pixels that do not display the first frame image FI 1  is the second level value corresponding to gray, the deviation of the accumulation brightness between the pixels located at the center of the pixel array  500  and the pixels located at the edge of the pixel array  500  may be small. As the deviation of the accumulation brightness is increased, the boundary of the frame image FI may be distinct. Therefore, the level value of pixels that do not display the first frame image FI 1  may be the second level value. 
       FIG. 18  illustrates another embodiment of a display device, and  FIG. 19  illustrates an embodiment for describing position information that is changed every predetermined time interval. 
     Referring to  FIGS. 18 and 19 , a display device  10  includes a control unit  300 , an image processing unit  100 , and a pixel array  500 . The control unit  300  generates an image control signal ICS and a position control signal PCS. The image processing unit  100  generates a frame image FI based on an image signal IS and the image control signal ICS. The image processing unit  100  provides the frame image FI and the position control signal PCS. The position control signal PCS includes position information PI where the frame image FI is located. The pixel array  500  includes base pixels  510  and addition pixels  530 . The pixel array  500  displays the frame image FI in the base pixels  510  and the addition pixels  530  based on the position control signal PCS. The number of the base pixels  510  correspond to a resolution of the frame image FI. The addition pixels  530  are different from the base pixels  510 . 
     In one embodiment, the control unit  300  may generate a background control signal BCS. The image processing unit  100  may output the background control signal BCS, the frame image FI, and the position control signal PCS. The pixel array  500  may select the one of the first level value or the second level value as the level value of pixels that do not display the frame image FI, among the base pixels  510  and the addition pixels  530 , based on the background control signal BCS. 
     In one embodiment, the position information PI may be changed based on a predetermined time interval PDT. For example, the control unit  300  may provide the first position control signal PCS 1  including the first position information PI 1 . After the predetermined time interval PDT, the control unit  300  may provide the second position control signal PCS 2  including the second position information PI 2 . After another predetermined time interval PDT, the control unit  300  may provide the third position control signal PCS 3  including the third position information PI 3 . Therefore, the position information PI may be changed based on the predetermined time interval PDT. For example, the predetermined time interval PDT may be less than three seconds. 
       FIG. 20  illustrates an embodiment for describing region where a frame image is displayed according to position information. Referring to  FIGS. 18 and 20 , the pixel array  500  may include the base pixels  510  and the addition pixels  530 . In case the control unit  300  provides a first position control signal PCS 1 , and provides a second control signal after the predetermined time interval PDT, the second position information PI 2  in the second position control signal PCS 2  may be the information corresponding to an adjacent pixel  550  of a pixel indicated by the first position information PI 1  in the first position control signal PCS 1 . 
     For example, the second position information may indicate one pixel-shift according to the first direction D 1  from the pixels where the first frame image FI 1  is displayed based on the first position control signal PCS 1 . Also, the second position information may indicate one pixel-shift according to the second direction D 2  from the pixels where the first frame image FI 1  is displayed based on the first position control signal PCS 1 . Also, the second position information may indicate one pixel-shift according to the third direction D 3  from the pixels where the first frame image FI 1  is displayed based on the first position control signal PCS 1 . Also, the second position information may indicate one pixel-shift according to the fourth direction D 4  from the pixels where the first frame image FI 1  is displayed based on the first position control signal PCS 1 . 
       FIG. 21  illustrates an embodiment of a display system  20  which includes a processor  15  and a display device  10 . The processor  15  provides an image signal IS. The display device  10  displays a frame image FI that is generated based on the image signal IS. The display device  10  includes a control unit  300 , an image processing unit  100 , and a pixel array  500 . The control unit  300  generates an image control signal ICS and a position control signal PCS. The image control signal ICS may be used to compose a frame image FI from an image signal IS. The position control signal PCS may be used to determine position where the frame image FI is displayed in the pixel array  500 . 
     The image processing unit  100  generates a frame image FI based on an image signal IS and the image control signal ICS. The image processing unit  100  provides the frame image FI and the position control signal PCS. The position control signal PCS includes position information PI where the frame image FI is located. For example, in a first time, the image processing unit  100  may provide the first frame image FI 1  and the first position control signal PCS 1  to the pixel array  500 . The first frame image FI 1  may be generated based on the image signal IS and the image control signal ICS. The first position control signal PCS 1  may include the position information PI where the first frame image FI 1  is located. 
     In a second time after the first time, the image processing unit  100  may provide the second frame image FI 2  and the second position control signal PCS 2  to the pixel array  500 . The second frame image FI 2  may be generated based on the image signal IS and the image control signal ICS. The second position control signal PCS 2  may include the position information PI where the second frame image FI 2  is located. A pixel corresponding to the position information PI included in the second position control signal PCS 2  may be an adjacent pixel  550  to a pixel corresponding to the position information PI included in the first position control signal PCS 1   
     A pixel array  500  includes base pixels  510  and addition pixels  530 . A pixel array  500  displays the frame image FI in the base pixels  510  and the addition pixels  530  based on the position control signal PCS. The number of the base pixels  510  correspond to a resolution of the frame image FI. The addition pixels  530  are different from the base pixels  510 . For example, the resolution of the frame image FI may be 3840*2160. In this case, the number of the base pixels  510  may be 3840*2160. The addition pixels  530  are different from the base pixels  510 . The addition pixels  530  may be located at one or more sides of the base pixels  510 . In one embodiment, the addition pixels  530  are located at first to fourth sides SIDE 1  to SIDE 4  of the base pixels  510 . 
     In one embodiment, the position information PI may be changed every predetermined time interval PDT. The control unit  300  may provide the position control signal PCS to the image processing unit  100  the every predetermined time interval PDT. Also, in one embodiment, in case the position information PI in the position control signal PCS is changed, the location where the frame image FI is displayed in the pixel array  500  is changed. 
       FIG. 22  illustrates an embodiment for describing a position control signal that is changed every predetermined time interval. Referring to  FIGS. 2 and 21 , the addition pixels  530  may be located at one or more sides of the base pixels  510 , e.g., at first to fourth sides SIDE 1  to SIDE 4  of the base pixels  510 . The number APN 1  of the first direction addition pixels added to the first side SIDE 1  according to the first direction D 1  may be equal to the number APN 3  of the third direction addition pixels added to the third side SIDE 3  according to the third direction D 3 . The number APN 2  of the second direction addition pixels added to the second side SIDE 2  according to the second direction D 2  may be equal to the number APN 4  of the fourth direction addition pixels added to the fourth side SIDE 4  according to the fourth direction D 4 . 
     For example, the number APN 1  of the first direction addition pixels added to the first side SIDE 1  according to the first direction D 1  may be 5. The number APN 3  of the third direction addition pixels added to the third side SIDE 3  according to the third direction D 3  may be 5. In this case, the number APN 1  of the first direction addition pixels and the number APN 3  of the third direction addition pixels may be the same number  5 . The number APN 2  of the second direction addition pixels added to the second side SIDE 2  according to the second direction D 2  may be 4. The number APN 4  of the fourth direction addition pixels added to the fourth side SIDE 4  according to the fourth direction D 4  may be 4. In this case, the number APN 2  of the second direction addition pixels and the number APN 4  of the fourth direction addition pixels may be the same number  4 . 
     In case the addition pixels  530  are located in the first to fourth sides SIDE 1  to SIDE 4  of the base pixels  510 , the number APN 1  of the first direction addition pixels and the number APN 3  of the third direction addition pixels may be equal. The number APN 2  of the second direction addition pixels and the number APN 4  of the fourth direction addition pixels may be equal. 
     In accordance with the present embodiment, changing the position where the frame image FI is displayed using the addition pixels  530  in the display device  10  reduces or prevents distortion of the frame image FI because the resolution of the frame image FI is maintained. Also, changing the position where the frame image FI is displayed using the addition pixels  530  may reduce or prevent an after-image effect. 
       FIG. 23  illustrates an embodiment of a mobile device  700  which includes a processor  710 , a memory device  720 , a storage device  730 , an input/output (I/O) device  740 , a power supply  750 , and an electroluminescent display device  760 . The mobile device  700  may further include a plurality of ports for communicating a video card, a sound card, a memory card, a universal serial bus (USB) device, or other electronic systems. 
     The processor  710  may perform various computing functions or tasks. The processor  710  may be for example, a microprocessor, a central processing unit (CPU), etc. The processor  710  may be connected to other components via an address bus, a control bus, a data bus, etc. Further, the processor  710  may be coupled to an extended bus such as a peripheral component interconnection (PCI) bus. 
     The memory device  720  may store data for operations of the mobile device  700 . For example, the memory device  720  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, and/or at least one volatile memory device such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, a mobile dynamic random access memory (mobile DRAM) device, etc. 
     The storage device  730  may be, for example, a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I/O device  740  may be, for example, an input device such as a keyboard, a keypad, a mouse, a touch screen, and/or an output device such as a printer, a speaker, etc. The power supply  750  may supply power for operating the mobile device  700 . The electroluminescent display device  760  may communicate with other components via the buses or other communication links. 
     The embodiments described herein may be applied to any mobile device or any computing device. For example, the embodiments described herein may be applied to a cellular phone, a smart phone, a tablet computer, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital camera, a music player, a portable game console, a navigation system, a video phone, a personal computer (PC), a server computer, a workstation, a tablet computer, or a laptop computer. 
     The methods, processes, and/or operations described herein may be performed by code or instructions to be executed by a computer, processor, controller, or other signal processing device. The computer, processor, controller, or other signal processing device may be those described herein or one in addition to the elements described herein. Because the algorithms that form the basis of the methods (or operations of the computer, processor, controller, or other signal processing device) are described in detail, the code or instructions for implementing the operations of the method embodiments may transform the computer, processor, controller, or other signal processing device into a special-purpose processor for performing the methods described herein. 
     Also, another embodiment may include a computer-readable medium, e.g., a non-transitory computer-readable medium, for storing the code or instructions described above. The computer-readable medium may be a volatile or non-volatile memory or other storage device, which may be removably or fixedly coupled to the computer, processor, controller, or other signal processing device which is to execute the code or instructions for performing the method embodiments described herein. 
     Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.