KR20080055139A - Display device and method of driving the same - Google Patents

Abstract

An OLED device and a method for driving the same are provided to reduce size thereof by implementing a data driver, which includes a first sub-data driver for driving at least two sub-pixels among first, second, and third sub-pixels. An OLED(Organic Light Emitting Display) device includes plural sub-pixels(108) and a data driver(114). The sub-pixels, which are formed at areas which data and scan lines cross each other, include first sub-pixels related to first data lines, second sub-pixels related to second data lines, and third sub-pixels related to third data lines among the data lines. The data driver includes a first sub-data driver for driving at least two sub-pixels among the first, second, and third sub-pixels.

Description

DISPLAY DEVICE AND METHOD OF DRIVING THE SAME}

1 is a view showing a stripe type display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a circuit of the display device of FIG. 1.

3 is a timing diagram illustrating the scan signals of FIG. 2.

4 is a diagram illustrating a circuit of a second sub data driver of FIG. 2 according to an exemplary embodiment of the present invention.

5 is a diagram illustrating a circuit of a second sub data driver of FIG. 2 according to another exemplary embodiment of the present invention.

6 illustrates a stack type display device according to a second exemplary embodiment of the present invention.

FIG. 7 is a diagram illustrating a circuit of the display device of FIG. 6.

8 illustrates a display device according to a third exemplary embodiment of the present invention.

The present invention relates to a display device and a method of driving the same, and more particularly, to a display device and a method of driving the same is reduced in size thereof.

The display device displays a predetermined image and includes a plurality of subpixels formed in regions where data lines and scan lines intersect each other.

The display device may include a plurality of sub data drivers respectively connected to the data lines, and provide data currents to the data lines using the sub data drivers. As a result, the subpixels emit light.

However, in the display device having such a structure, since the sub data driver must be connected to each data line as described above, the number of the sub data driver is too large to increase the size of the display device.

It is an object of the present invention to provide a display element whose size is reduced and a method of driving the same.

In order to achieve the above object, the organic electroluminescent device according to an exemplary embodiment of the present invention includes a plurality of sub pixels and a data driver. The subpixels are formed in regions where the data lines and the scan lines intersect, wherein the first subpixels associated with the first data line, the second subpixels associated with the second data line, and the first subpixels are formed. Have third sub-pixels associated with the three data lines. The data driver includes a first sub data driver for driving at least two sub pixels among the first sub pixels, the second sub pixels, and the third sub pixels.

First subpixels associated with a first data line and second subpixels associated with a second data line are formed at intersections of data lines and scan lines according to an exemplary embodiment of the present invention. The driver for driving an organic light emitting device including a plurality of subpixels having pixels and third subpixels associated with a third data line includes a scan driver and a data driver. The scan driver transmits scan signals to the scan lines. The data driver provides first data currents to one of the first sub-pixels, the second sub-pixels, and the third sub-pixels to drive the one sub-pixels, and the other two sub-subs. And a second sub data driver for supplying second data currents to the pixels to drive the two sub pixels. Here, the data signals are synchronized with the scan signals.

First subpixels associated with a first data line and second subpixels associated with a second data line are formed at intersections of data lines and scan lines according to an exemplary embodiment of the present invention. A method of driving an organic electroluminescent device comprising a plurality of subpixels having pixels and third subpixels associated with a third data line, comprises: (a) a first subpixel associated with the first data line during a first emission time; Driving second sub pixels associated with the second data line; And (b) driving the first sub pixels associated with the first data line and the third sub pixels associated with the third data line during a second emission time.

The display device and the method of driving the same according to the present invention drive one of the subpixels associated with two data lines by using one sub data driver, thereby reducing the size of the display device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a stripe type display device according to a first embodiment of the present invention.

Referring to FIG. 1, the display element of the present embodiment includes a panel 100 and a driver 102.

The display device according to an exemplary embodiment of the present invention includes an organic electroluminescent device (PDP), a plasma dispaly panel (PDP), a liquid crystal display (LCD), and the like.

The panel 100 includes subpixels 108 formed in regions where the first electrode layers 104 and the second electrode layers 106 intersect.

According to one embodiment of the invention, the first electrode layer 104 is made of an anode electrode layer, the second electrode layer 106 is made of a cathode electrode layer.

Each subpixel 108 includes an emission layer made of an organic material.

Thus, as predetermined voltages are applied to the electrode layers 104 and 106, holes and electrons provided from the electrode layers 104 and 106 combine in the light emitting layer to form excitons, and then the excitons are decomposed to predetermined wavelengths. Light having is emitted from the light emitting layer.

The driver 102 includes a controller 110, a scan driver 112, and a data driver 114, and the circuit structure of the driver 102 is the same as FIG. 2.

FIG. 2 is a diagram illustrating a circuit of the display device of FIG. 1, and FIG. 3 is a timing diagram illustrating scan signals of FIG. 2.

Referring to FIG. 2, the panel 100 includes a plurality of subpixels E11 to E64 formed in regions where the data lines D1 to D6 and the scan lines S1 to S4 intersect. Here, three sub-pixels positioned consecutively, for example, E11, E21 and E31 form one pixel.

According to an embodiment of the present invention, the subpixels E11 to E14 and E41 to E44 associated with the data lines D1 and D4 are red subpixels, and the subpixels associated with the data lines D2 and D5. (E21 to E24, E51 to E54) are green subpixels, and the subpixels E31 to E34 and E61 to E64 associated with the data lines D3 and D6 are blue subpixels.

The controller 110 receives a plurality of display data from an external device (not shown), and controls the scan driver 112 and the data driver 114 according to the received display data.

The scan driver 112 transmits the scan signals SP1 to SP4 as shown in FIG. 3 to the scan lines S1 to S4 under the control of the controller 110 to sequentially turn the scan lines S1 to S4. Choose. Here, each of the scan signals SP1 to SP4 includes a low logic period, that is, a light emission period (light emission time) and a high logic period, that is, a non-light emission period. That is, subpixels corresponding to the scan signals SP1 to SP4 emit light in the low logic periods of the scan signals SP1 to SP4. Since this driving method is a general method, a description thereof will be omitted.

The data driver 114 includes first to fourth sub data drivers IS1 to IS4, and data signals generated from the first to fourth sub data drivers IS1 to IS4, preferably a data current. Are supplied to the subpixels E11 to E64 to drive the subpixels E11 to E64.

In detail, the first sub data driver IS1 supplies the first data current to the data line D1 to drive the first sub pixels E11 to E14.

The second sub data driver IS2 supplies a second data current to one selected data line among the data lines D2 and D3 to drive the subpixels associated with the selected data line. However, when the data line D2 is selected in the first frame, the data line D3 is selected in the second frame that is the next frame of the first frame. That is, the data lines D2 and D3 are selected alternately for each frame. Here, the frame means a screen when the panel 100 implements an image as a whole. In detail, the frame is obtained when the sub-pixels E11 to E64 associated with the scan lines S1 to S4 emit light to display a predetermined image as the scan lines S1 to S4 are selected one by one. Point to the screen.

The third sub data driver IS3 operates similarly to the first sub data driver IS1, and the fourth sub data driver IS4 operates similarly to the second sub data driver IS2.

Hereinafter, since the first sub data driver IS1 and the third sub data driver IS3 are the same as the conventional sub data driver, only the operations of the second and fourth sub data drivers IS2 and IS4 will be described in detail. However, since the fourth sub data driver IS4 is formed of a circuit similar to the second sub data driver IS2, only the structure and operation of the second sub data driver IS2 are referred to the accompanying drawings for convenience of description. Will be described in detail.

4 is a diagram illustrating a circuit of a second sub data driver of FIG. 2 according to an exemplary embodiment of the present invention, and FIG. 5 is a circuit diagram of a second sub data driver of FIG. 2 according to another exemplary embodiment of the present invention. One drawing.

Referring to FIG. 4, the second sub data driver IS2 includes a data current generator 400 and a switching unit 402.

The data current generator 400 includes a reference current source, a first P-MOS transistor M0, second P-MOS transistors M1 to M6, switches SW1 to SW6, and a third P-MOS transistor M7. ), A fourth P-MOS transistor M8 and a fifth P-MOS transistor M9.

The reference current source generates a reference current Iref, and the first P-MOS transistor MO is connected in series with the reference current source.

The second P-MOS transistors M1 to M6 are arranged to form a mirror circuit with the first P-MOS transistor M0. However, the second P-MOS transistors M1 to M6 preferably have different sizes, that is, ratios of different widths to lengths (W / L).

The switches SW1 to SW6 are connected in series to the second P-MOS transistors M1 to M6, respectively.

The third P-MOS transistor M7 is commonly connected to the switches SW1 to SW6 and is turned on for a time T corresponding to a low logic period of the scan signal.

The fourth P-MOS transistor M8 is connected in series with the third P-MOS transistor M7 and together with the fifth P-MOS transistor M9 forms a mirror circuit.

The switching unit 402 includes a first switch connected to the data line D2 and a second switch connected to the data line D3.

The first switch is turned on / off in response to an odd signal (OS), and the second switch is turned on / off in response to an even signal (ES). Here, the odd signal OS and the even signal ES are opposite signals, so that when the one of the first switch and the second switch is turned on, the remaining switch is turned on. It is turned off. As a result, the data current generated from the data current generator 400 is provided to only one of the data lines D2 and D3 so that the subpixel associated with the data line emits light.

Although not shown above, the first sub data driver (eg, IS1) also includes a data current unit and a third switch for switching the data current unit and the corresponding data line.

According to an embodiment of the present invention, when the first to third switches are respectively composed of first to third MOS transistors, the difference between the threshold voltages of the first and second MOS transistors is the threshold of the first and third MOS transistors. The voltages are greater than the difference and the difference between the threshold voltages of the second and third MOS transistors. That is, subpixels corresponding to the first and third MOS transistors having a small difference in threshold voltages emit light in the first frame, and subpixels corresponding to the second and third MOS transistors emit light in the next frame.

Referring to FIG. 5, the data current generator 500 may include first P-MOS transistors connected in series to a reference current source, second P-MOS transistors constituting a mirror circuit with the first P-MOS transistors, respectively. And switches SW1 to SWk connected to the second P-MOS transistors, and generate data currents using the components.

In other words, the second sub data driver IS2 of the present exemplary embodiment generates a first data current through the data current generator 400 or 500 in the first frame and converts the generated first data current into the data lines D2. And D3) to the selected data line. Thereafter, the second sub data driver IS2 provides the second data current generated from the current generator 400 or 500 to the data line not selected in the first frame in the second frame after the first frame. do. This process is repeated frame by frame.

Here, the user viewing the display device of the present invention does not actually recognize the image displayed on the panel 100 in one frame unit, but recognizes the image in a plurality of frames, for example, in units of eight frames. Therefore, when the image is implemented in units of two frames, the user may not actually recognize the image.

Therefore, the display element of the present invention drives one pixel in units of two frames. For example, the display device drives only the red subpixel and the green subpixel in the first frame, and drives the red subpixel and the blue subpixel in the second frame. As a result, over the first frame and the second frame, all of the red subpixels, the green subpixels, and the blue subpixels are driven to display a predetermined image on the panel 100. As a result, the display element of the present invention can reduce its size while displaying the same image as the conventional one to the user.

In the above embodiments, both the circuit of FIG. 4 and the circuit of FIG. 5 may be used as the second sub data driver IS2, but the circuit of FIG. 5 finely adjusts the level of data current than the circuit of FIG. 4. Therefore, it is preferable to use the circuit of FIG. 5 as the 2nd sub data drive part IS2.

FIG. 6 illustrates a stack type display device according to a second exemplary embodiment of the present invention, and FIG. 7 illustrates a circuit of the display device of FIG. 6.

As shown in FIG. 6, in the stack-typed display element, the number of the second electrode layers 612 is half of the number of the second electrode layers 106 of the first embodiment that are stripe type. However, the width of the second electrode layers 612 is twice the width of the second electrode layers 106 of the first embodiment. Therefore, the stack type display element has the circuit structure shown in FIG. 7, and the resistance of the scan lines S1 and S2 in the second embodiment is smaller than the resistance of the scan lines S1 to S4 in the first embodiment. . As a result, the characteristics of the display element of the second embodiment are superior to those of the display element of the first embodiment.

In particular, in the organic EL device in which the resistance characteristics of the scan lines S1 to S4 are important, it is preferable to use the stack type rather than the stripe type.

In terms of data lines, the number of stack type data lines D1 to D12 is twice as large as the stripe type data lines D1 to D6. In this case, the display element of the second embodiment constitutes the sub data drivers as shown in FIG. However, since the sub data drivers IS1 to IS8 function similarly to the sub data drivers IS1 to IS4 of the first embodiment, a description thereof will be omitted.

In the above, the number of the second electrode layers 612 included in the stack type panel 600 has been described as half the number of the second electrode layers 106 of the stripe type panel 100. However, the stack type panel 600 is not limited to the above method. That is, based on the panel having the same size, for example, 160 (number of sub-pixels arranged in the vertical direction) x 360 (number of sub-pixels arranged in the horizontal direction), A panel including a number of second electrode layers 612 smaller than the number of second electrode layers 106 is defined as a stack type panel 600.

In other words, the display device of the present invention drives two data lines using one sub data driver regardless of stripe type or stack type.

6 and 7, the control unit 604, the scan driver 606, and the data driver 608 perform functions similar to those of the components of the first embodiment, and thus the description thereof will be omitted.

8 illustrates a display device according to a third exemplary embodiment of the present invention.

Referring to FIG. 8, the display device according to the present exemplary embodiment includes a panel 800, a controller 804, a first scan driver 806, a second scan driver 808, and a data driver 810.

The remaining components except for the scan drivers 806 and 808 perform the same functions as the components of the first embodiment, and thus descriptions thereof will be omitted.

Scan drivers 806 and 808 are formed in both directions of panel 800, unlike the first embodiment.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art having ordinary knowledge of the present invention will be able to make various modifications, changes, additions within the spirit and scope of the present invention, such modifications, changes and Additions should be considered to be within the scope of the following claims.

As described above, the display device and the method of driving the same according to the present invention drive one of the subpixels related to two data lines by using one sub data driver, and thus, the size of the display device can be reduced. There is this.

Claims (22)

A first subpixel associated with a first data line, a second subpixel associated with a second data line, and a third data line formed in regions where data lines and scan lines intersect. A plurality of sub pixels having third sub pixels; And And a data driver having a first sub data driver configured to drive at least two sub pixels among the first sub pixels, the second sub pixels, and the third sub pixels. The method of claim 1, wherein the first sub data driver drives two of the first sub pixels, the second sub pixels, and the third sub pixels. And the data driver further comprises a second sub data driver for driving the other sub pixels. The organic light emitting diode of claim 1, wherein the first sub data driver alternately drives the two sub pixels for each frame. The organic electroluminescent device according to claim 3, wherein the two sub pixels driven by the first sub data driver are green sub pixels and blue sub pixels. The organic light emitting device of claim 1, wherein the first sub-pixels emit red light, the second sub-pixels emit green light, and the third sub-pixels emit blue light. The method of claim 2, wherein the first sub data driver, A first data current generator for generating a data current; And And a switching unit for switching a connection of data lines associated with the subpixels driven by the first data current generator and the first sub data driver. The method of claim 6, wherein the switching unit, A first switch for switching a connection between the first data current generator and one of the data lines; And A second switch for switching the connection of the first data current generator and the remaining data line, The organic light emitting device of claim 1, wherein one of the first switch and the second switch is turned on and the other is turned off. The organic electroluminescent device according to claim 7, wherein the first switch comprises a first MOS transistor and the second switch comprises a second MOS transistor. The method of claim 8, wherein the second sub data driver, A second data current generator for generating a data current; LAC A third MOS transistor for switching the connection between the second data current generator and the data line, And a difference between threshold voltages of the first and second MOS transistors is greater than a difference between threshold voltages of the first and third MOS transistors and a difference between the second and third threshold voltages. The method of claim 6, wherein the first data current generating unit, A reference current source for generating a reference current; A first P-MOS transistor connected to the reference current source; Second P-MOS transistors constituting a mirror circuit with the first P-MOS transistor; A third P-MOS transistor jointly connected to the second P-MOS transistors; And And a fourth P-MOS transistor constituting a mirror circuit with the third P-MOS transistor. The method of claim 6, wherein the first data current generating unit, A reference current source for generating a reference current; First P-MOS transistors connected in series with the reference current source; Second P-MOS transistors constituting a mirror circuit with the first P-MOS transistors; And And a plurality of switches for switching the connection of the second P-MOS transistors and the switching unit. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device is a stripe type organic electroluminescent device. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device is a stack type organic electroluminescent device. Data lines and scan lines are formed at intersections, and the first subpixels associated with the first data line, the second subpixels associated with the second data line, and the third data line are associated with the first data line. In a driver for driving an organic electroluminescent device comprising a plurality of sub pixels having third sub pixels, A scan driver to transmit scan signals to the scan lines; And A first sub data driver for supplying first data currents to one of the first sub pixels, the second sub pixels, and the third sub pixels to drive the one sub pixels and the other two sub pixels. A data driver having a second sub data driver for providing two data currents to drive the two sub pixels, The data signals are synchronized with the scan signals. The method of claim 13, wherein the second sub data driver, A data current generator for generating the data currents; And And a switching unit for switching a connection of data lines associated with the subpixels driven by the data current generator and the second sub data driver. The method of claim 14, wherein the switching unit, A first switch for switching the connection of the data current generator and one of the data lines; And A second switch for switching the connection of the data current generator and the remaining data line, And wherein one of the first switch and the second switch is turned on and the other is turned off during the light emission operation. The method of claim 14, wherein the data current generating unit, A reference current source for generating a reference current; A first P-MOS transistor connected to the reference current source; Second P-MOS transistors constituting a mirror circuit with the first P-MOS transistor; A third P-MOS transistor jointly connected to the second P-MOS transistors; And And a fourth P-MOS transistor constituting a mirror circuit with the third P-MOS transistor. The method of claim 14, wherein the data current generating unit, A reference current source for generating a reference current; First P-MOS transistors connected in series with the reference current source; Second P-MOS transistors constituting a mirror circuit with the first P-MOS transistors; And And a plurality of switches for switching a connection between the second P-MOS transistors and the switching unit. 15. The driver of claim 14, wherein the second sub data driver alternately drives the two sub pixels for each frame. Data lines and scan lines are formed at intersections, and the first subpixels associated with the first data line, the second subpixels associated with the second data line, and the third data line are associated with the first data line. A method of driving an organic electroluminescent device comprising a plurality of subpixels having third subpixels, the method comprising: (a) driving first subpixels associated with the first data line and second subpixels associated with the second data line during a first emission time; And and (b) driving the first subpixels associated with the first data line and the third subpixels associated with the third data line during a second emission time. The method of claim 20, wherein the steps (a) and (b) are repeatedly performed. 21. The method of claim 20, wherein the second sub pixels are green sub pixels that generate green light, and the third sub pixels are blue sub pixels that generate blue light.

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