Patent Publication Number: US-7586506-B2

Title: Light emitting display device and method of driving the same

Description:
CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application for LIGHT EMITTING DISPLAY DEVICE AND METHOD OF DRIVING THE SAME earlier filed in the Korean Intellectual Property Office on Sep. 22, 2004 and thereby duly assigned Serial No. 2004-75820. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to a video signal processing method and a display device using the same and, more specifically, to a video signal processing method and a delta-structured display device that can be used in a small display where input video signals are rearranged for use in a delta pixel structure in a programmable logic circuit. 
     2. Discussion of Related Art 
     In general, a display device uses video signals to display predetermined images. The video signals indicate information about an image for display on a screen. Such video signals are typically input to a controller of the display device from the external device, and then transmitted to each pixel through a driving portion according to the control of the controller. 
     A display device generally has a stripe pixel structure or a delta pixel structure. The stripe pixel structure is a structure where pixels, each having a red pixel, a green pixel and a blue pixel are arranged in a straight line. The delta pixel structure (hereinafter, referred to as a ‘delta-structure’) is a structure where pixels, each having a red pixel, a green pixel and a blue pixel, are arranged approximately in a triangle across two lines. A delta-structure display device will be described below. 
     Generally, curves and moving images are more effectively and efficiently displayed on a display that uses a delta structure instead of the stripe structure. However, in order to process video signals for a delta structure display effectively, a large memory and a high-end central processing unit (CPU) are needed. This is problematical for small displays as small displays do not and can not always contain large memories or CPUs. Therefore, what is needed is a method and an apparatus for displaying video signals having a delta structure that can easily be implemented in small-sized displays. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an improved method for displaying delta structure video data on a display. 
     It is also an object of the present invention to provide an improved display device that displays images using the delta structure. 
     It is further an object of the present invention to provide a method of displaying video data that can be applied to a small display that uses a delta-type structure. 
     It is yet another object of the present invention to provide a design for a small display that inverts and displays video signals according to a delta-type structure. 
     It is still an object of the present invention to provide a video signal processing method that can be applied to a small delta-structured display device absent a driver integrated circuit (IC). 
     It is also an object of the present invention to provide a video signal processing method capable of optimizing a driving portion in a driver IC in a delta-structure display device. 
     It is yet an object of the present invention to provide a delta-structure display device employing the novel video signal processing method. 
     These and other objects can be achieved by a method of processing a video signal for a light emitting display device that includes receiving sequentially first line video signals and second line video signals, each having a plurality of sub video signals such as a red sub video signal, a green sub video signal, and a blue sub video signal, extracting alternately one of the red sub video signals, the green sub video signals, and the blue sub video signals from at least two successive video signals of the first line video signals and storing the extracted signal into a memory as the first line delta video signals, and extracting alternately one of the red sub video signals, the green sub video signals, and the blue sub video signals from at least two successive video signals of the second line video signals and storing the extracted signal into the memory as the second line delta video signals. 
     The storing of the extracted second line delta video signals into the memory can include reading the extracted first line delta video signals from the memory followed by storing the extracted first line delta video signals into the memory. In addition, storing the extracted second line delta video signals into the memory can include reading the extracted first line delta video signals from a first region of the memory while recording the extracted first line delta video signals into a second region of the memory. In addition, the memory can include a line memory having a storage capacity of at least one horizontal line. 
     The method can further include sequentially providing the first line delta video signals and the second line delta video signals to a data driving portion. Here, the first line delta video signals and the second line delta video signals can be provided to the data drive circuit by delaying by a predetermined clock cycle the second line delta video signals preceded by the predetermined clock cycle to the first line delta video signals such that a start position of the second line delta video signals is aligned to a start position of the first line delta video signals. 
     The method can further include providing the first line delta video signals to data lines in an image display portion during a first horizontal period where first scanning signals are applied to first scanning lines, and providing the second line delta video signals to the data lines during a second horizontal period following the first horizontal period where second scanning signals are applied to second scanning lines. 
     The sequentially receiving the first and second line video signals can include sequentially receiving odd signals and even signals of the first line video signals and odd signals and even signals of the second line video signals, respectively, in parallel. 
     The extracting the first and second line delta video signals can include extracting the first and second line delta video signals from even signals of the first line video signals and odd signals of the second line video signals, respectively. 
     The extracting the first and second line delta video signals can include extracting the first and second line delta video signals by inverting an order of extracting the odd signals and the even signals, based on a direction of shifting signals by a shift register in a scan driver. 
     The extracting the first and second line delta video signals can include extracting the first and second line delta video signals by inverting an order of extracting the red sub video signal, the green sub video signal, and the blue sub video signals from the odd signals of the first line video signals and the even signals of the second line video signals, based on a data signal applying direction between a first direction extending in a scanning direction and a second direction opposite to the first direction. 
     Another aspect of the present invention is to provide a display device that includes a scan driver adapted to supply scanning signals to a plurality of scanning lines a data driver adapted to supply data signals to a plurality of data lines a plurality of pixels arranged in a delta, each pixel comprises a light emitting diode electrically connected to one of the scanning lines and one of the data lines and a controller adapted to control the scanning signals and the data signals supplied to the plurality of pixels, wherein the controller also being adapted to sequentially receive first line video signals and second line video signals, each having a plurality of video signals having red sub video signals, green sub video signals, and blue sub video signals, alternately extract one of the red sub video signals, the green sub video signals, and the blue sub video signals for at least two video signals of the first line video signals and stores the extracted signals into a memory as the first line delta video signals, alternately extract one of the red sub video signals, the green sub video signals, and the blue sub video signals for at least two video signals of the second line video signals and stores the extracted signals into a memory as the first line delta video signals, and sequentially supply the first line delta video signals and the second line delta video signals to the data driver. The controller can include a low voltage differential signal (LVDS) interface adapted to receive odd signals and even signals of the first line video signals and odd signals and even signals of the second line video signals, respectively, in parallel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference symbols indicate the same or similar components, wherein: 
         FIG. 1  is a view of a delta-structured display device; 
         FIG. 2  is a view of a video signal processing method in the delta-structured display device; 
         FIG. 3  is a view of a delta-structured display device according to an embodiment of the present invention; 
         FIG. 4  is a view of a circuit diagram of a pixel circuit of a delta-structured display device of  FIG. 3 ; 
         FIG. 5  is a view of a data driver of the delta-structured display device of  FIG. 3 ; 
         FIG. 6  is a view of a flow chart illustrating a video signal processing method employed in a delta-structured display device according to an embodiment of the present invention; 
         FIG. 7  is a view of rearrangement of a video signals according to a delta structure in the delta-structured display device according to an embodiment of the present invention; 
         FIG. 8  is a view of a drive timing diagram for a delta-structured display device according to an embodiment of the present invention; 
         FIG. 9  is a view of a video signals transmitted to each pixel in a delta-structured display device according to an embodiment of the present invention; 
         FIG. 10  is a view of a video signal processing method where the signal is transmitted to a delta-structured display device through an LVDS interface according to an embodiment of the present invention; and 
         FIGS. 11 through 13  are views of video signal processing methods when a screen display direction is inverted in the delta-structured display device according to other embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to the figures,  FIG. 1  is a view of a delta-structured display device and  FIG. 2  is a view of video signals supplied to the display device of  FIG. 1 . Referring to  FIG. 1 , the delta-structured display device includes an image display portion  10 , a scan driver  20 , a data driver  30 , and a controller  40 . Further, the delta-structured display device includes a plurality of pixels  11  arranged in the delta-structure within the image display portion  10 . Strictly speaking, each pixel  11  in display portion  10  includes to one of the red, green, and blue pixels. 
     The image display portion  10  includes a plurality of scanning lines S 1 , S 2 , S 3 , S 4 , . . . , Sn- 1 , and Sn for transferring scanning signals, a plurality of data lines D 1 , D 2 , D 3 , . . . , and Dm- 1 , Dm for transferring data signals, and a plurality of pixels  11  electrically connected to the scanning lines and the data lines. The pixels  11  include, for example, a light emitting diode (not illustrated) and a pixel circuit (not illustrated) for controlling the light emitting diode. 
     The scan driver  20  supplies scanning signals to the scanning lines S 1 , S 2 , S 3 , S 4 , . . . , Sn- 1 , and Sn using signals output from a shift register (not illustrated). For example, the scan driving circuit  20  supplies scanning signals to each pixel  11  in a single scanning scheme or a sequential scanning scheme. The data driver  30  converts the video signals transmitted from the controller  40  into the data signals appropriate to the pixel structure, and then, sequentially supplies the data signals to data lines D 1 , D 2 , D 3 , . . . , Dm- 1 , and Dm in the image display portion  10  by each one horizontal line. 
     The controller  40  generates a control signal and a clock signal to control the scan driver  20  and the data driver  30 . Here, the control signal includes a vertical sync signal, a horizontal sync signal, and a start pulse. In addition, the controller  40  stores the video signals to be input to a frame memory (not illustrated), etc., and supplies the video signals to the data driver  30  by each one frame. Here, the controller  40  handles the video signals as first video signals of odd horizontal lines and second video signals of even horizontal lines such that the video signals are suitable for the delta structure. For example, as illustrated in  FIG. 2 , the controller  40  converts RGB video signals of RGB Data, sequentially input from the external device (not illustrated) into first video signals of the odd horizontal lines (or signals corresponding to a first line) and second video signals of the even horizontal lines (or signals corresponding to a second line) in synchronization with the horizontal sync signal HSYNC and a clock signal CLK such that the RGB data is suitable for the delta structure. 
     Displaying a curve or a moving image is best accomplished using a delta-structured display device as opposed to using a stripe pixel structure. For this reason, delta-structured pixel arrangements are preferably used over a stripe-type pixel arrangement. However, the delta-structured display device requires that the input video signals conform to the delta structure, thus requiring complex manipulations of the input RGB video signals to transform them into odd horizontal lines and even horizontal lines while changing the order thereof. Therefore, a large memory and a high-speed operation device such as a CPU needs to be mounted in most delta-structured display devices. This results in an increase of the manufacturing costs of the display device and also an increase in the weight and the size of the display device. 
     Also, in a small display devices, a control circuit unit arranged as a programmable logic chip type such as a field programmable gate array is used instead of the high-speed operation device such as a CPU. When the small display device uses the delta structure, the small delta-structured display device needs to perform a relatively large amount of operations, but the small display device does not have a high-speed CPU operation device or a large capacity memory to effectively and efficiently process the delta structured video signals. As a result, it is difficult to apply the delta-structured display device in a small display device. 
     Turning now to  FIG. 3 ,  FIG. 3  is a view of a delta-structured display device according to an embodiment of the present invention. In  FIG. 3 , the delta-structured display device is formed in a structure where data signals for displaying the same color are applied to one signal line. Referring to  FIG. 3 , the delta-structured display device according to an embodiment of the present invention processes and displays the input video signals RGB appropriate for the delta structure. As illustrated in  FIG. 3 , the delta-structured display device includes an image display portion  100 , a scan driver  200 , a data driver  300 , and a controller  500 . 
     The image display portion  100  includes a plurality of scanning lines S 1 , S 2 , S 3 , S 4 , . . . , Sn- 1 , and Sn for transferring scanning signals, and a plurality of data lines D 1 , D 2 , D 3 , . . . , Dm- 1 , and Dm for transferring data signals, and a plurality of pixels  110  electrically connected to the scanning lines and data lines, respectively. Here, red, green, and blue pixels  110  arranged in two scanning lines forms a delta pixel that displays a unit pixel having a delta structure. 
     In the display of  FIG. 3 , each pixel  110  includes a light emitting diode (LED) where predetermined voltages Vdd and Vss are applied at both ends and a pixel circuit  120  that controls the LED. As illustrated in  FIG. 4 , the pixel circuit  120  includes a second transistor M 2  for transferring data signals of the data line Dm to a gate of the first transistor M 1  in response to the scanning signal of the scanning line Sn, and a capacitor Cst for storing a voltage corresponding to the data signals transferred through the second transistor M 2 , the first transistor M 1  acts as a predetermined current source corresponding to the voltage stored in the capacitor Cst. The LED emits light having a predetermined color and intensity in response to the current flowing from the first transistor M 1 . 
     The scan driver  200  uses signals output from a shift register (not illustrated) to supply scanning signals to the scanning lines S 1 , S 2 , S 3 , S 4 , . . . , Sn- 1 , and Sn. For example, the scan driver  200  supplies the scanning signal to each pixel  110  in any one scanning scheme among a single scanning scheme, a sequential scanning scheme, a dual scanning scheme, an interfaced scanning scheme, and other scanning schemes. Here, each scanning scheme according to the present embodiment can be appropriately adjusted and applied to be suitable for the delta structure. 
     The data driver  300  supplies data signals or delta video signals to each pixel  110  such that the pixels  110  arranged in the delta structure can display the predetermined images, respectively. For example, after the data driver  300  converts the video signals transferred from the controller  500  into the data signal, it sequentially supplies the data signals having an amount of one horizontal line to each data line D 1 , D 2 , D 3 , . . . , Dm- 1 , and Dm in the image display portion  100 . 
     In addition, the data driver  300  can perform processing such as gamma correction and D/A conversion in order to convert the delta video signals into the data signals that are suitable for the image display portion. For example, as illustrated in  FIG. 5 , the data driver  300  can include a shift register  310 , a first latch  320 , a second latch  330 , and a D/A converter (DAC)  340 . The data driver  300  can include a plurality of shift registers  310  or a plurality of DAC  340  in order to process the delta video signals and the R, G, and B signals, respectively. 
     The shift register  310  respectively provides first and second latch enable signals for sequentially storing delta video signals (Delta RGB) in the first latch  320  and transferring them to the second latch  330  according to a clock signal HCLK and a horizontal sync signal HSYNC. Further, the first latch  320  sequentially stores the delta video signals in response to the first latch enable signal, and the second latch  330  receives the delta video signals of one horizontal line from first latch  320  according to the second enable signal of the shift register  310 . Further, the DAC  340  coverts the delta video signals of one horizontal line transferred from the first latch  320  into data signals, and transmits the data signals to the image display portion  100 . 
     Referring back to  FIG. 3 , the controller  500  controls the scan driver  200  and the data driver  300  by generating a control signal and a clock signal. In addition, the controller  500  rearranges the video signals RGB into the delta video signals (Delta RGB), and stores the delta video signals into the memory  540 , and then supplies the delta video signals of one horizontal line to the data driver  300 . In order to do this, the controller  500  includes an interface  510 , a timing controller  520 , a video signal converter  530 , and a memory  540 . 
     The interface  510  receives signals by converting analog video signals input from an external source into digital video signals. On the other hand, the interface  510  can receive the digital video signals input from an external source. In addition, the interface  510  can be implemented with a low-voltage differential signaling (LVDS) interface that uses 3.3V or 1.5V that is lower than the standard 5V voltage typically used in the display device, as an electrical connection between, for example, the controller  500  and the host device (not illustrated) such as a motherboard to which the controller  500  is connected. 
     The timing controller  520  generates a clock signal and a control signal. Here, the control signal includes a vertical sync signal, a horizontal sync signal, and a start signal, etc. The timing controller  520  supplies the clock signal and the control signal to the video signal converter  530 , the scan driver  200 , and the data driver  300 . 
     The video signal converter  530  sequentially receives the first line video signals RGB, and the second line video signals RGB, according to the clock signal from the timing controller  520 . Here, the first and second line video signals include a plurality of video signals, and each video signal includes a red sub video signal, a green sub video signal, and a blue sub video signal. 
     The video signal converter  530  also extracts the first sub video signals from any one of the red, green, and blue sub video signals of the even signals in the first line video signals, alternately or sequentially for storage of the first sub video signals into the memory  540 . Here, the first sub-video signals stored in the memory  540  form the first line delta video signals. 
     In addition, the video signal converter  530  extracts the second sub video signals from any one of the red, green, and blue sub video signals of the odd signals in the second line video signals following the first line video signal, alternately or sequentially for storage of the second sub video signals into the memory  540 . Here, the second sub-video signals stored in the memory  540  form the second line delta video signals. 
     The video signal converter  530  also sequentially stores the first line delta video signals and the second line delta video signals into the memory  540  and sequentially reads them and provides them to the data driver  300 . The video signal converter  530  is preferably implemented as a programmable logic chip  550  such as a field programmable gate array (FPGA). 
     The memory  540  is provided as a memory having a capacity where the video signals supplied to at least one horizontal line can be stored. In addition, the memory  540  can have a capacity where the video signals supplied to at least two horizontal lines can be stored to facilitate processing of the video signal. In this case, first, the memory  540  stores the first line delta video signals supplied to the first horizontal lines of the delta structure, and then reads the first line delta video signals while recording the second line delta video signals supplied to the second horizontal lines adjacent to the first horizontal lines at the same time. 
     In addition, when the memory  540  is provided as a programmable logic chip  550  such as the FPGA, it can be formed within the logic chip  550  along with the video signal converter  530 . In this case, the memory  540  can be formed as a line memory having a storage capacity of at least horizontal line. In addition, the memory  540  can be implemented as a random access memory (RAM), a read only memory (ROM), and a video memory such as an additional high-speed memory. 
     In the following description, a video signal processing method in the controller  500 , and in the video signal converter  530  of the controller  500  will be described in detail in conjunction with  FIGS. 6 and 7 . Turning now to  FIG. 6 ,  FIG. 6  is a view of a flow chart of a video signal processing method employed in the delta-structured display device according to an embodiment of the present invention.  FIG. 7  is a view used to explain the step of rearranging the video signals in the delta-structured display device according to an embodiment of the present invention. 
     Referring to  FIGS. 6 and 7 , first, the controller sequentially receives the video signals (RGB Data), including the first line video signals and the second line video signals (S 10 ). Here, the first line video signals refer to video signals transferred in the first horizontal lines or one horizontal line of the image display portion having a delta structure, and the second line video signals refer to video signals transferred in the second horizontal lines or another horizontal line adjacent to the first horizontal line. Further, each video signal in the first and second line video signals includes a red sub video signal Rn (where n is a natural number), a green sub video signal Gn, and a blue sub video signal Bn. 
     The controller then sequentially extracts the first sub video signals R 1 _ 4 , G 1 _ 6 , and B 1 _ 8  of any one of the red, green, and blue sub video signals between at least two successive video signals from the first line video signals, according to a clock signal AD_CLK (S 20 ). Here, the video signals to be transferred to the first horizontal lines are rearranged or mapped to correspond to the first line of the delta structure. The controller then stores the first sub video signals as the first line delta video signals R 1 _ 4 , G 1 _ 6 , and B 1 _ 8  to be transferred to the first horizontal lines (S 30 ). Next, the controller supplies the first line delta video signals stored in the memory to the data driver (S 40 ). 
     The controller then sequentially extracts the second sub video signals R 2 _ 1 , G 2 _ 3 , B 2 _ 5 , R 2 _ 7 , and G 2 _ 9  of any one of the red, green, and blue sub video signals between at least two successive video signals from the second line video signals, according to the clock signal AD_CLK (S 50 ). Here, the video signals to be transferred to the second horizontal lines are mapped to correspond to the second line of the delta structure. The controller then stores the second sub video signals as the second line delta video signals R 2 _ 1 , G 2 _ 3 , B 2 _ 5 , R 2 _ 7 , and G 2 _ 9  to be transferred to the second horizontal lines (S 60 ). 
     The controller then supplies the second line delta video signals stored in the memory to the data driver (S 70 ). Here, the controller supplies the second line delta video signals by delaying them as much as the predetermined clock cycle so that a start position of the second delta video signals are matched to a start position of the first line delta video signals. For example, unlike the stripe pixel structure display device, the delta-structured display device has a difference of 3 clock cycles with respect to the pixel that displays the same color. Therefore, for the delta-structured display device that supplies the same color to the same data line, when the video signals are actually mapped, the second sub video signal of the first one of the even signals are delayed as much as 3 clock cycles to allow the second sub video signal to be input to the data line to which the first sub video signal of the first one of the odd signal. 
     Further, the first line delta video signals and the second line delta video signals described above are alternately extracted from the respective line video signals input sequentially and mapped. In addition, the first line delta video signals and the second line delta video signals described above can be extracted from the even signals of the first line video signals and the odd signals of the second line video signals, respectively. 
     Further, when the memory has a storage capacity of more than two horizontal lines, the controller can use the memory in a manner that the controller records the subsequent delta video signals while storing the delta video signals of more than two horizontal lines into the memory or reading one delta video signal. 
     In addition, the first and second delta video signals described above can be formed such that the first and second sub video signals of the red R, green G, and blue B are sequentially extracted in a different order such as B, G, R instead of the order R, G, B. 
     Delta images displayed in the delta structure image display portion will now be described with reference to  FIGS. 8 and 9 . Turning now to  FIGS. 8 and 9 ,  FIG. 8  is a view of a drive timing diagram for the delta-structured display device according to an embodiment of the present invention and  FIG. 9  is a view of video signals transferred to the respective pixels within the image display portion of the delta-structured display device according to an embodiment of the present invention. In  FIG. 9 , the image display portion has  220  scanning lines and  528  data lines for each RGB. Thus, in  FIG. 8 , Sn and Dm can be S 220  and D 528 , respectively. 
     Referring to  FIGS. 8 and 9 , when low level scanning signals are sequentially applied to a plurality of scanning lines S 1 , S 2 , S 3 , S 4 , . . . , and S 220  in one frame period in the delta-structured display device, the delta video signals are sequentially supplied to a plurality of data lines D 1 , D 2 , D 3 , D 4 , . . . , and D 528  for one horizontal line period where the scanning signals are applied. 
     In the delta structure image display portion  100 , the delta pixel  130  includes one or two pixels  110  connected to the first line and two or one pixels  110  connected to the second line. In this embodiment, the first line of the delta pixel  130  becomes the odd scanning lines S 1 , S 3 , S 5 , . . . , and S 219 , and the second line thereof becomes the even scanning lines S 2 , S 4 , . . . , and S 220 . 
     Further, the delta video signals supplied from the controller to the data driver are D/A converted or gamma corrected before being transmitted to the image display portion  100 . In this case, the delta video signals are converted into the corresponding data signals and supplied from the data driver to the respective data lines. 
     The delta video signals slashed in  FIG. 8  (i.e., the data signals R 2 _ 1 , R 4 _ 1 , . . . , R 220 _ 1  of  FIG. 8 ) as well as B 1 _ 1060 , B 3 _ 1060 , B 5 _ 1060 , . . . , B 219 _ 1060  (not illustrated) refer to dummy signals not substantially indicated on the image display portion  100  illustrated in  FIG. 9 . Further, in each data line D 1 , D 2 , D 3 , D 4 , D 5 , . . . , D 526 , D 527 , and D 528  of  FIG. 9 , the delta video signals displaying the same color of any one of the red R, green G, and the blue B delta video signals are sequentially supplied for the horizontal period where each scanning signal is applied. By doing so according to the present invention, the delta-structured display device without a need of a driver IC and/or a frame memory can be readily implemented. 
     Turning now to  FIG. 10 ,  FIG. 10  is a view of a method of processing video signals transferred through an LVDS interface in the delta-structured display device according to an embodiment of the present invention. The embodiment of  FIG. 10  is substantially the same as the embodiment illustrated in  FIG. 7  except for the LVDS interface. Therefore, portions of the description that overlap that of  FIG. 7  are omitted. 
     Referring to  FIGS. 3 and 10 , when the interface  510  in the controller  500  is implemented as an LVDS interface, the delta-structured display device according to an embodiment of the present invention receives the first and second line video signals divided as the odd signals and the even signals and are sequentially input. Further, the controller  500  extracts the first line delta video signals from the first line video signals divided and input as the odd signals and the even signals, and extracts the second line delta video signals from the second line video signals divided and input as the odd signals and the even signals, and stores the extracted signals into the memory  540  sequentially. 
     For example, the first line delta video signals R 1 _ 4 , G 1 _ 6 , and B 1 _ 8  are extracted from the even signals of the first line video signals, and the second line delta video signals R 2 _ 1 , G 2 _ 3 , B 2 _ 5 , R 2 _ 7 , and G 2 _ 9  are extracted from the odd signals of the second line video signals. 
     Next, for example, since the start positions of the first and second line delta video signals have one and one half clock cycle difference viewing from the delta structure layout, the controller  500  supplies the second line delta video signals to the data driver  300  by delaying them as much as one and one half clock cycles, when the second delta video signal is supplied to the data driver  300 . 
     Like this, when the delta-structured display device according to an embodiment of the present invention uses an LVDS interface, the image data can be processed more effectively. In addition, in the delta-structured display device according to an embodiment of the present invention, even when the screen display direction is inverted to the top and bottom and left and right, the image data can be processed much more easily. 
     A method of processing video signals when the screen display direction is inverted in the delta-structured display device will now be described in conjunction with  FIGS. 11 through 13 .  FIGS. 11 through 13  are views of a video signal processing methods when a screen display direction is inverted in the delta-structured display device according to embodiments of the present invention. 
     Turning now to  FIG. 11 ,  FIG. 11  is a view of a video signal processing method according to another embodiment of the present invention for a case where the direction where the scanning signals are applied in a shift register (not illustrated) within the scan driver of the delta-structured display device is inverted. In other words, the embodiment of  FIG. 11  is directed to a case where, when the scanning signals are sequentially provided in the first direction from the shift register (not illustrated) of the scan driver corresponding to the video signal processing method of  FIG. 10 , the scanning signals are sequentially provided in the second direction opposite to the first direction. 
     For the embodiment of  FIG. 11 , the delta-structured display device having the LVDS interface according to the present invention sequentially extracts the first line delta video signals B 1 _ 1 , G 1 _ 3 , R 1 _ 5 , B 1 _ 7 , and G 1 _ 9  from the odd signals of the input first line video signals and stores the extracted first line delta video signals into the memory as signals to be supplied to the first line of the delta structure, and extracts the second line delta video signals B 2 _ 4 , G 2 _ 6 , and R 2 _ 8  from the even signals of the input second line video signals following the first line video signals and stores these extracted signals the memory as signals to be supplied to the second line adjacent to the first line of the delta structure. Next, the first and second line delta video signals are transferred to the image display portion through the data driver to display the images with the screen direction upside down. With the arrangement described above, the delta-structured display device according to the embodiment of  FIG. 11  readily inverts the screen display direction between top and bottom while displaying the delta video signals on the image display portion. 
     Turning now to  FIG. 12 ,  FIG. 12  is a view of a video signal processing method for an embodiment where the direction where the data signals are applied from the shift register (not illustrated) within the data driver is inverted. In other words, the embodiment of  FIG. 12  is directed to a case where, when the data signals are provided in the third direction from the shift register (not illustrated) of the data driver corresponding to the video signal processing method of  FIG. 10 , the data signals are sequentially provided in the fourth direction opposite to the third direction. 
     For the above embodiment of  FIG. 12 , the delta-structured display device having the LVDS interface according to  FIG. 12  sequentially extracts the first line delta video signals R 1 _ 1 , G 1 _ 3 , B 1 _ 5 , R 1 _ 7  and G 1 _ 9  from the odd signals of the input first line video signals and stores the extracted first line delta video signals into the memory as signals to be supplied to the first line of the delta structure, and sequentially extracts the second line delta video signals R 2 _ 4 , G 2 _ 6 , and B 2 _ 8  from the even signals of the input second line video signals following the first line video signals and stores these extracted signals into the memory as signals to be supplied to the second line adjacent to the first line of the delta structure. Next, the first and second line delta video signals are transferred to the image display portion through the data driver to display the images with the screen direction left side to the right. With the arrangement described in conjunction with  FIG. 12 , the delta-structured display device according to  FIG. 12  readily inverts the screen display direction between left and right while displaying the delta video signals on the image display portion. 
     Turning now to  FIG. 13 ,  FIG. 13  is a view of a video signal processing method where the direction that the scanning signals are applied in a shift register (not illustrated) within the scan driver of the delta-structured display device is inverted and the direction where the data signals are applied from the shift register (not illustrated) within the data driver is also inverted. In other words, the embodiment of  FIG. 13  is directed to where, when the scanning signals are sequentially provided in the first direction from the shift register (not illustrated) of the scan driver, and when the data signals are provided in the third direction from the shift register (not illustrated) of the data driver corresponding to the video signal processing method of  FIG. 10 , the data signals are sequentially provided in the second direction opposite to the first direction and in the fourth direction opposite to the third direction. 
     For the embodiment of  FIG. 13 , the delta-structured display device having the LVDS interface sequentially extracts the first line delta video signals B 1 _ 4 , G 1 _ 6 , and R 1 _ 8  from the odd signals of the input first line video signals and stores the extracted first line delta video signals into the memory as signals to be supplied to the first line of the delta structure, and sequentially extracts the second line delta video signals B 2 _ 1 , G 2 _ 3 , R 2 _ 5 , B 2 _ 7 , and G 2 _ 9  from the even signals of the input second line video signals following the first line video signals and stores these extracted signals into the memory as signals to be supplied to the second line adjacent to the first line of the delta structure. The first and second line delta video signals are then transferred to the image display portion through the data driver to display the images with the screen direction upside down and left side to the right. With the arrangement described in conjunction with  FIG. 13 , the delta-structured display device readily inverts the screen display direction between top and bottom and left and right while displaying the delta video signals on the image display portion. 
     In the embodiments described herein, the pixel circuit is an essential pixel circuit in a voltage-writing scheme including the drive transistor M 1  and the switching transistor M 2 . However, the embodiments of the present invention can also be applied to a pixel circuit in a voltage-writing scheme including a transistor for compensating a threshold voltage of the drive transistor and a transistor for compensating a voltage drop other than the switching transistor and the drive transistor. Moreover, the embodiments of the present invention can be applied to a pixel circuit in a current writing scheme where data signals are supplied as data currents, as well as the pixel circuit in the voltage-writing scheme. 
     In addition, while the above embodiments have been described with reference to a transistor of the pixel circuit having a source, a drain, and a gate, each transistor can be arranged with a first electrode indicating a source or a drain, a second electrode indicating a drain or a source, and a gate. In other words, the MOS transistor in the pixel circuit described above is just illustrative. Therefore, the pixel circuit of the present invention can include other types of transistors besides MOS transistors. For example, the transistor can be implemented as including a first electrode, a second electrode, and a third electrode, and as an active device where a current amount flowing from the second electrode to the third electrode can be controlled by a voltage applied between the first and second electrodes. 
     In addition, according to the embodiments described above, the second transistor M 2  of the pixel circuit is a device for switching electrodes at both sides in response to the scanning signal, and can also be implemented with various switching devices capable of performing the same function. 
     In addition, according to the embodiments described above, the LEDs can be formed with an electroluminescent device (EL) that can be an inorganic EL device formed with an emission layer with inorganic matter as well as an organic EL device formed with organic matter. 
     In addition, according to the embodiments described above, the scan driver and the data driver of the display device can be directly mounted on a glass substrate on which the image display portion is formed, and can be replaced with a drive circuit where scanning lines, data lines, and the transistor are is formed coplanar on the substrate having the image display portion thereon. On the other hand, the scan driver and/or the data driver can be provided in a chip on flexible board or a chip on film (COF). In other words, the scan driver and/or the data driver can be mounted as a flexible printed circuit (FPC) or a film attached and electrically connected to the substrate. 
     According to the present invention, the data driver in the driver IC adapted to the delta-structured display device can be maximized. In addition, the delta-structured display device on which the high-speed operation device is not mounted can appropriately display delta images. Further, a small electronic apparatus mounted with the delta-structured display device for displaying more natural curve or moving picture can be provided at a lower cost. 
     Although a few embodiments of the present invention have been illustrated and described, it would be appreciated by those skilled in the art that changes might be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.