KR20060124962A - Organic light emitting diodes, display and method for driving the same - Google Patents

Abstract

An OLED(Organic Light Emitting Diode), an organic electroluminescence display device, and a driving method thereof are provided to reduce the number of data lines and to use one data driving unit while increasing the resolution, and to secure the uniform image quality. An OLED includes a plurality of sub pixels for expressing one color; scan lines(S1~S3N) electrically connected to plural sub pixels, respectively; and data lines(D1~DM) electrically connected to plural sub pixels at the same time. Each of plural sub pixels has red, green, blue, and white organic light emitting layers. Each of plural sub pixels has a TFT(Thin Film Transistor) having a source connected with the scan line, a gate coupled with the data line, and a drain connected with a pixel electrode contacted with the organic light emitting layer.

Description

Organic light emitting diode and organic light emitting display device, driving method thereof {Organic Light Emitting Diodes, Display and Method for Driving the same}

1 is a schematic plan view of a conventional active matrix organic light emitting display device.

2 is a plan view of an organic light emitting display device according to an embodiment of the present invention;

3 is an enlarged plan view of a scan driver, a data driver, and a pixel unit of FIG. 2;

4 is an enlarged plan view of the gamma part and the data driver of FIG. 2;

5A and 5B illustrate driving waveforms of data signals of a conventional organic light emitting display device and an organic light emitting display device according to an embodiment of the present invention.

The present invention relates to an organic light emitting display device using an organic light emitting display device and a driving method thereof.

Organic Light Emitting Diodes (OLEDs) are self-luminous devices that emit fluorescent materials by recombination of electrons and holes. The organic electroluminescent display market using the same is faster than the passive light emitting device that requires a separate light source, such as a liquid crystal display device, the response speed is fast, the DC drive voltage is low and ultra-thin film is possible to be applied to the wall-mounted or portable.

Such an organic light emitting display device implements color using pixels in which red, blue, and green subpixels represent one color. At this time, the organic light emitting display device is an active matrix organic light emitting display device (Active Matrix) which is driven by using a simple matrix OLED (PMOLED) and a thin film transistor (TFT). OLED, AMOLED). A simple matrix type organic light emitting diode (PMOLED) is formed so that an anode and a cathode are orthogonal, and a line is selected and driven, whereas an active matrix organic light emitting diode (AMOLED) connects a TFT and a capacitor to each of the ITO pixel electrodes to form a capacitor. It is a driving method to maintain the voltage by the capacitance.

1 is a schematic plan view of a conventional active matrix type organic light emitting display device.

Referring to FIG. 1, a conventional active matrix type organic light emitting display device 10 includes a plurality of pixels 14 in which R, G, and B subpixels 12 represent one color, and R, G. And a scan driver 16 for supplying a scan signal or a selection signal to the B subpixels 12, and a data driver for supplying a data signal or an image signal to the R, G, and B subpixels 12 in response to the scan signal. Had 18.

The scan driver 16 sequentially supplies the scan signals to the sub pixels 12 through the scan lines S ₁ , S ₂ , S ₃ , ....., S _N-1 , S _N , and the data. The driver 18 supplies the data signals to the sub pixels 12 through the data lines D ₁ , D ₂ , D ₃ ,..., D _3M-1 , and D _3M .

That is, the conventional active matrix organic light emitting display device 10 is branched from the data driver 18 to transmit a plurality of data lines D ₁ , D ₂ , D ₃ ,..., D _{3M -1} , D _3M ) and a plurality of scan lines S ₁ , S ₂ , S ₃ , ...., S _N-1 , S _N branching from the scan driver 16 to transmit a selection signal. Arranged to intersect, these data lines (D ₁ , D ₂ , D ₃ ... D _3M-1 , D _3M ) and scan lines (S ₁ , S ₂ , S ₃ , ...., S _N-1 , Sub-pixels 12 at each intersection of S _N ).

The conventional active matrix organic light emitting display device 10 has a structure in which the data driver 18 and the data electrodes D ₁ , D ₂ , D ₃ ,..., D _3M-1 , D _3M are connected one-to-one. Was used. Therefore, in the conventional active matrix type organic light emitting display device 10 having a resolution of M × RGB × N, the data line is performed for each subpixel R, G, and B constituting one pixel 14. (D ₁ , D ₂ , D ₃ ) were connected, which required M × 3 data lines. At this time, N number of scan lines was required.

For example, in the case of having a resolution (QCIF +) of 176 × RGB × 220, 176 × 3 data lines and 220 scan lines were required.

However, the conventional active matrix type organic light emitting display device 10 has a problem that the number of data lines (M × 3) increases in high resolution, and thus the number of channels of the data driver 18 connected one-to-one with the data lines increases. there was. When the number of channels of the data driver 18 increases, there is only a method of arranging two or more data drivers 18 in parallel.

As a result, the conventional active matrix type organic light emitting display device 10 has a large number of data lines in the case of high resolution and uses two or more data driving units 18, thus not only causing a cost increase but also two or more data driving units ( 18) has caused a serious problem of image quality non-uniformity at the boundary.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an organic light emitting display device, an organic light emitting display device, and a method of driving the same, which reduce the number of data lines and use only a minimum data driver even when the resolution is increased. have.

Another object of the present invention is to provide an organic light emitting display device, an organic light emitting display device, and a method of driving the same, which have a low manufacturing cost and provide uniform image quality.

In order to achieve the above technical problem, the present invention provides a plurality of subpixels representing one color, scan lines electrically connected to the plurality of subpixels, and a plurality of subpixels simultaneously. Provided is an organic light emitting display device having a data line connected thereto.

In another aspect, the present invention provides a plurality of sub-pixels formed at each intersection of scan lines and data lines to display an image, and are electrically connected to the plurality of pixels representing one color and the scan lines. A scan driver for supplying a scan signal to the subpixels to enable the subpixels sequentially through the scanlines, and the data lines are electrically connected to subpixels corresponding to one pixel at the same time to supply the data signal through the datalines. An organic light emitting display device having a data driver for supplying a plurality of subpixels is provided.

In this case, the plurality of subpixels may be subpixels including red, green, and blue organic light emitting layers. In addition, the plurality of subpixels may be four subpixels further including a white organic light emitting layer.

In addition, each of the plurality of subpixels may include a thin film transistor having a scan line connected to a source, a data line connected to a gate, and a pixel electrode contacting the organic light emitting layer and a drain connected thereto.

In addition, one data signal supplied through one data line may be time-divided by the number of subpixels to output the data signal.

In addition, the data driver may adjust the gamma value according to the luminous efficiency of the subpixels.

In addition, the data driver may have a data selector for supplying driving pulses of a plurality of subpixels to one data line.

In another aspect, the present invention provides a driving method of an organic light emitting display device having a plurality of pixels formed at each intersection of scan lines and data lines and displaying an image. And a scanning step of supplying the subpixels with a scan signal that sequentially enables the subpixels through the scanlines, and simultaneously connecting the datalines with subpixels corresponding to one pixel in response to the scan signal. The present invention provides a method of driving an organic light emitting display device having a data driving step of supplying a data signal to a plurality of subpixels through data lines.

In this case, one data signal supplied through one data line may be time-divided by the number of subpixels to output the data signal.

In addition, a gamma correction step of adjusting the gamma value according to the luminous efficiency of the subpixels may be further included.

In addition, the data signal may be time-divided by switching the data signals of the red, green, and blue subpixels including the red, green, and blue organic light emitting layers in response to the scan signals.

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

2 is a plan view of an organic light emitting display device according to an exemplary embodiment of the present invention, and FIG. 3 is an enlarged plan view of the scan driver, the data driver, and the pixel unit of FIG. 2.

Referring to FIG. 2, the organic light emitting display device 20 according to the exemplary embodiment of the present invention includes a controller 22, a driver 24, and a pixel circuit unit 26.

The controller 22 supplies an interface 28 that receives data from an external system, a timing controller 30 that controls the driver 24 according to the data R, G, and B and a control signal, and supplies power from the outside. It has a power supply unit 32 and the DC / DC converter 34 for supplying power to the internal components.

The control unit 22 further has a gamma unit 36 for adjusting the gamma value of the data R, G, and B. The gamma part 36 together with the driving part 24 will be described later in detail.

2 and 3, the driver 24 includes a scan driver 38 and a data driver 40.

The scan driver 38 is electrically connected to scan lines S ₁ , S ₂ , S ₃ ,..., S _N-1 , S _N electrically connected to the pixel circuit unit 26. The scan driver 38 sequentially rotates the pixel circuit through the scan lines S ₁ , S ₂ , S ₃ ,..., S _3N-1 and S _3N according to a control signal supplied from the timing controller 30. The scan signal or the selection signal for enabling the 26 is supplied to the pixel circuit unit 26.

The data driver 40 is electrically connected to the data lines D ₁ , D ₂ , D ₃ ... D _M-1 , D _M electrically connected to the pixel circuit unit 26. The data driver 40 transmits data to the pixel circuit unit 26 through the data lines D ₁ , D ₂ , D ₃ ... D _M-1 , D _M according to a control signal supplied from the timing controller 30. Supply the signal.

2 and 3, the pixel circuit unit 26 has pixels 42 composed of subpixels Rs, Gs, and Bs. The subpixels Rs, Gs, and Bs include red, green, and blue organic light emitting layers.

The pixel circuit unit 26 includes scan lines S ₁ , S ₂ , S ₃ ,..., S _3N-1 , S _3N and data lines D ₁ , D ₂ , D ₃ ... D _{M At} each intersection of _-1 , D _M , three sub pixels R, G, and B displaying an image form a pixel 42 representing one color. Each of the plurality of subpixels Rs, Gs, and Bs has a scan line S connected to a source, a data line D connected to a gate, and a pixel electrode contacting the red, green, and blue organic light emitting layers. It includes a thin film transistor (T) is connected to the drain.

In this case, the three subpixels R, G, and B constituting one pixel 42 have one data line, for example, D ₁ and three scan lines, for example, S ₁ , S ₂ , and S _3. It is formed at the intersection of.

Therefore, when the resolution is M × RGB × N, the number of data lines is M and the number of scan lines is 3N. Therefore, the number of pins (number of channels) of the data driver 40 corresponding to the data line in one-to-one decreases so that one data driver 40 can be used even if the resolution is large.

FIG. 4 is an enlarged plan view of the gamma part and the data driver of FIG. 2.

After gamma correction of the data R / n, G / n, and B / n provided from the timing controller 40 with reference to FIG. 4, the R, G, and B data signals are converted into one data line. A method of driving the R, G, and B subpixels by supplying the to the second pixel will be described.

One color and luminance of the pixel 42 is determined according to the combination of the light emission amounts of the R, G, and B subpixels. However, when the R, G, and B data signals are supplied to the R, G, and B subpixels through one data line, white balance is used when the same gamma value is used according to the luminous efficiency of the R, G, and B subpixels. Difficult to fit.

Referring to FIG. 4, the gamma part 36 according to the present invention adjusts white balance by applying different gamma values to R, G, and B data (R / n, G / n, and B / n). R, G, and B data (R / M, G / M, B / M) gamma-corrected by the gamma part 36 is supplied to the data driver 40.

For example, in the case of actual linear gamma, full white may be 255 and middle gray may be 127, but in gamma 2.3, full white may be 255 and middle white may be 76. At this time, in order to match the white balance, the full white of R and B is 255, but in the case of G, the gamma value can be adjusted to be 179. These gamma values can be changed to reflect the characteristics of the organic light emitting display device or the characteristics of the panel.

The data driver 40 converts the gamma-corrected R, G, and B data (R / M, G / M, B / M) into an analog signal or a driving pulse by the D / A converter 43, and then selects data. The unit 44 supplies three R, G, and B drive pulses to one data line. The data selector 44 is switched at regular intervals for the three R, G, and B drive pulses to supply driving pulses for driving the R, G, and B subpixels to the data line.

5A illustrates a driving waveform of a data signal of a conventional organic light emitting display device.

Referring to FIG. 5A, in the related art organic light emitting display, driving pulses supplied to subpixels by one data line are supplied to only one subpixel, for example, R subpixels, and one driving cycle is performed every cycle. Only pulses were supplied.

5B is a driving waveform of a data signal supplied to subpixels of an organic light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 5B, driving pulses of three R, G, and B data signals are supplied to three subpixels in one cycle by the data selector 44 of the data driver 40. That is, a driving pulse capable of driving the R, G, and B subpixels corresponding to R1, R2, and R3 is supplied to the first period 1H, and R, R2, and R3 corresponding to R1, R2, and R3 in the next period 2H. A driving pulse capable of driving the G and B subpixels is supplied.

As mentioned above, although an embodiment of the present invention has been described in detail with reference to the drawings, the present invention is not limited thereto.

In the above embodiment, although the gamma part 36 is formed in the controller 22, the gamma part 36 may be formed inside the data driver 40. That is, the white balance or the gamma value can be more easily adjusted by applying different gamma values for each of the R, G, and B subpixels as register settings inside the data driver 40.

In the above embodiment, only the R, G, and B subpixels have been described as an example, but one pixel may be configured by additionally including a W subpixel (white subpixel) for white balance. In this case, the white balance may be matched using the gamma part 36 and the W subpixel. The R, G, B, and W subpixels may also be connected to one data line and driven using driving pulses time-divided into four periods. Of course, the number of subpixels is only three or four, but may be changed as necessary.

In the above embodiment, the timing controller 30 and the data driver 40 are described as being separately present, but the controller 20 of the organic light emitting display device such as the timing controller 30, the data driver 40, and the level shift and The driver 24 may be implemented in one chip SOC.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. I can understand that. Therefore, since the embodiments described above are provided to fully inform the scope of the invention to those skilled in the art, it should be understood that they are exemplary in all respects and not limited. The invention is only defined by the scope of the claims.

According to this configuration, the present invention has the effect of reducing the number of data lines even when the resolution is increased and using only a minimum data driver.

In addition, the present invention has another effect that can provide a low cost and uniform image quality.

Claims (16)

A plurality of subpixels representing one color; Scan lines electrically connected to the plurality of subpixels, respectively; An organic light emitting display device having a data line electrically connected to the plurality of subpixels at the same time. The method of claim 1, The plurality of subpixels are subpixels including red, green, and blue organic light emitting layers. The method of claim 2, The plurality of subpixels are four subpixels further comprising a white organic light emitting layer. The method according to any one of claims 1 to 3, Each of the plurality of subpixels includes an organic light emitting diode including a thin film transistor having a scan line connected to a source, a data line connected to a gate, and a pixel electrode and a drain connected to the organic light emitting layer. . A plurality of pixels formed at each intersection of the scan lines and the data lines, and the plurality of sub-pixels representing one image represent one color; A scan driver electrically connected to the scan lines to supply scan signals to the sub pixels to sequentially enable the sub pixels through the scan lines; And a data driver configured to electrically connect the data lines to the subpixels corresponding to one pixel to supply data signals to the plurality of subpixels through the data lines. The method of claim 5, The plurality of subpixels are subpixels including red, green, and blue organic light emitting layers. The method of claim 6, The plurality of subpixels are four subpixels further including a white organic light emitting layer. The method according to any one of claims 5 to 7, Each of the plurality of subpixels includes an organic light emitting diode including a thin film transistor having a scan line connected to a source, a data line connected to a gate, and a pixel electrode and a drain contacting the organic light emitting layer. Display. The method of claim 8, And one data signal supplied through the one data line are time-divided by the number of the plurality of subpixels to output a data signal. The method of claim 8, And the data driver further comprises a gamma part for adjusting a gamma value according to the luminous efficiency of the subpixels. The method of claim 10, And the data driver comprises a data selector for supplying driving pulses of a plurality of subpixels to one data line. A driving method of an organic light emitting display device having a plurality of pixels formed at each intersection of scan lines and data lines and displaying an image, the plurality of subpixels representing one color. Supplying a scan signal to the subpixels to sequentially enable the subpixels through the scan lines; An organic field having a data driving step in which the data lines are electrically connected to the subpixels corresponding to one pixel at the same time to supply a data signal to the plurality of subpixels through the data lines A method of driving a light emitting display device. The method of claim 12, The plurality of subpixels are subpixels including red, green, and blue organic light emitting layers. The method of claim 13, And one data signal supplied through the one data line are time-divided by the number of the plurality of subpixels to output a data signal. The method of claim 14, And a gamma correction step of adjusting a gamma value according to the luminous efficiency of the subpixels. The method according to claim 14 or 15, And the data signal is time-divided by switching data signals of red, green, and blue subpixels including red, green, and blue organic light emitting layers in response to the scan signal.

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