Organic light emitting display device and method for driving thereof

An organic light emitting display device for displaying 2D and 3D image, the organic light emitting display device including a scan driver for supplying a scan signal to a plurality of scan lines; a data driver for supplying a data signal to a plurality of data lines; a plurality of pixels that located at crossing regions of the scan lines and the data lines for controlling a current flowing from a first power driver to a second power driver via an organic light emitting diode; a data processor for classifying data supplied from outside as 2D or 3D data, and for producing 2D or 3D; and a timing controller for transmitting 2D or 3D data supplied from the data processor to the data driver, wherein the timing controller is configured to set the pixels in a non-emission state during a scan period.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0043505, filed on May 10, 2010, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND

Embodiments of the present invention relate to an organic light emitting display device and a method of driving thereof, and more particularly, to an organic light emitting display device that displays 2D and 3D images, and a method of driving thereof.

2. Discussion of Related Art

Recently, a variety of flat panel displays that reduce or address disadvantages of cathode ray tubes, such as weight and volume, have been developed. Typical flat panel displays include liquid crystal displays, field emission displays, plasma display panels, organic light emitting display devices, etc.

The organic light emitting display device of the flat display devices displays an image using organic light emitting diodes that emit light by recombination of electrodes and holes, and has high response speed and is driven with low power consumption.

In general, organic light emitting display devices are classified into passive matrix organic light emitting display devices (PMOLEDs) and active matrix organic light emitting display devices (AMOLEDs), in accordance with the types of driving the organic light emitting diodes.

An active matrix organic light emitting display device typically includes a plurality of scan lines, a plurality of data lines, a plurality of power source lines, and a plurality of pixels coupled with the lines and arranged in a matrix. A pixel commonly includes an organic light emitting diode, a driving transistor for controlling the amount of current supplied to the organic light emitting diode, a switching transistor for transmitting a data signal to the driving transistor, and a storage capacitor for maintaining voltage of the data signal.

The types of organic light emitting display devices may be divided up into organic light emitting display devices for displaying 2D images and organic light emitting display device for displaying 3D images in response to an image (or image data) to display. The organic light emitting display devices for 2D images are for displaying 2D images on a panel and include most organic light emitting display devices that have been used so far. The organic light emitting display devices for 3D images are for displaying 3D images on a panel, and presently, research on this is actively in progress.

Meanwhile, the organic light emitting devices are generally only capable of displaying only 2D or 3D in the panel, as mentioned above, and as such two display devices are required in order to watch 2D and 3D images. Therefore, it would be useful to have an organic light emitting display device that is capable of displaying 2D and 3D images at the same time.

SUMMARY

Embodiments of the present invention are directed to an organic light emitting display device that can display 2D and 3D images, and a method for driving thereof.

According to one embodiment, there is provided the organic light emitting display device including: a scan driver for supplying a scan signal to a plurality of scan lines; a data driver for supplying a data signal to a plurality of data lines; a plurality of pixels located at crossing regions between the scan lines and the data lines, and for controlling a current flowing from a first power driver to a second power driver via an organic light emitting diode in accordance with the data signal; a data processor for classifying data supplied from outside the organic light emitting display device as 2D or 3D data, and for producing 2D or 3D data of at least two frames by using 2D or 3D data of one frame; and a timing controller for transmitting 2D or 3D data supplied from the data processor to the data driver, wherein the timing controller is configured to set the pixels in a non-emission state during a scan period during which the scan signal is supplied to the scan lines during one frame period.

The data processor may include a data divider for classifying the data into 2D or 3D data by using a distinguishing bit of the data supplied from the outside; a 3D data processor for producing data for a frame corresponding to a left eye image and data for a frame corresponding to a right eye image by using 3D data of one frame; a 2D data processor for producing data for at least two frames by using 2D data of one frame; and a data transmitter for transmitting data from the 3D data processor and the 2D data processor to the timing controller.

The data processor may be supplied with data from outside at a first driving frequency and may be configured to transmit 3D data and 2D data to the timing controller at a second driving frequency and the second driving frequency may be greater than the first driving frequency. The first driving frequency may be 60 Hz and the second driving frequency may be 120 Hz. The organic light emitting display device may further include a wireless transmitter coupled to the timing controller for transmitting a wireless signal corresponding to the scan period; and a pair of shutter glasses that may be configured to synchronize a response period with the scan period in accordance with the wireless signal.

The organic light emitting display device may further include a first power driver for producing the first power and a second power driver for producing the second power. The timing controller may be configured to control the first power driver to supply the first power at a low level during the scan period during one frame and the first power at a high level during the emission period. The timing controller may be configured to control the second power driver to supply the second power at a high level during the scan period among one frame and the second power at a low level during the emission period. The organic light emitting display may further include an emission control line coupled to the pixels in common, and the timing controller may be configured to control the scan driver to supply an emission control signal to the emission control line during the scan period.

According to one embodiment of the present invention, a method for driving an organic light emitting display device includes supplying data from outside the organic light emitting display device; classifying the data of one frame into 2D data or 3D data by using a distinguishing bit of the data; producing data of a frame corresponding to a left eye image and data of a frame corresponding to a right eye image by using the 3D data of one frame or producing data of two frames by using the 2D data of one frame when classifying into 2D data; producing a data signal by using the produced 3D data or the produced 2D data; setting a plurality of pixels in a non-emission state during a scan period for supplying the data signal to the pixels during one frame period; and setting the pixels to emit light in accordance with the data signal during an emission period.

The method may further include controlling a current flowing from a first power driver to a second power driver via the organic light emitting diode during the emission period using the pixels in accordance with the data signal. The method may further include setting a voltage of the first power at a low level during the scan period, and setting the voltage of the first power at a high level during the emission period.

The method may further include setting a voltage of the second power at a high level during the scan period, and setting the voltage of the second power at a low level during the emission period. The pixels may include a control transistor coupled between the organic light emitting diode and the first power driver, and the method may further include turning off the control transistor during the scan period and turning on the control transistor during the emission period. An i-th (here, i is a natural number) frame may include the left eye image and i+1 frame may include the right eye image when displaying image using the 3D data. The method may also include synchronizing the scan period between an emission period of the i-th frame and an emission period of the (i+1)-th frame with a response period of a pair of shutter glasses.

According to an organic light emitting display device and a method for driving thereof according to embodiments of the present invention, 2D and 3D images can be displayed in one panel by classifying data supplied from outside into 2D data and 3D data, and producing additional frame data in accordance with to the 2D data and the 3D data, respectively.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments, in which one skilled in the field can easily perform the present invention, will be described in more detail with reference toFIG. 1toFIG. 13B.

FIG. 1is a block diagram illustrating an organic light emitting display device according to an embodiment of the present invention.

Referring toFIG. 1, the organic light emitting display device according to an embodiment of the present invention includes: a display unit130including pixels140that are coupled with scan lines S1to Sn, a light emission control line E, and data lines D1to Dm; a scan driver110that supplies a scan signal to the scan lines S1to Sn and supplies a light emission control signal to the light emission control line E; a data driver120that supplies a data signal to the data lines D1to Dm; a first power driver160for supplying a first power ELVDD to the pixels140; a second power driver150for supplying a second power ELVSS to the pixels140; and a timing controller180for controlling the scan driver110, the data driver120, the first power driver160, and the second power driver150.

In addition, the organic light emitting display device according to one embodiment of the present invention includes a data processor170that divides data inputted from outside into 2D and 3D Data′ and delivers the Data′ to the timing controller180, and a wireless transmitter190for emitting a wireless signal of (or corresponding to) a period expressing black during one frame period (e.g., a non-emission period).

The scan driver110supplies the scan signal to the scan lines S1to Sn during one frame period. The scan driver110also supplies the light emission control signal to the light emission control line E during the scan period.

In this case, the light emission control signal is set at a voltage level at which a transistor can be turned-off, and the scan signal is set at a voltage level at which a transistor can be turned-on. Therefore, when the scan signal is set at a high level (or low level) voltage, the light emission control signal is set at a low level (or high level) voltage.

In one embodiment, the light emission control line E is coupled with all of the pixels140, and the pixels140during supplying the light emission control signal are set in a non-light emitting state. In other words, according to one embodiment of the present invention, the pixels140are set in the non-light emitting state by supplying the light emission control signal during the scan period of one frame period, and the pixels140are set in the light emitting state by stopping the supply of the light emission control signal during an emission period (e.g., in periods other than the scan period of one frame period).

The data driver120supplies the data signal to the data lines D1to Dm in synchronization with the scan signal that is successively supplied to the scan lines S1to Sn.

The display unit130includes pixels140disposed at crossing regions of the scan lines S1to Sn and the data lines D1to Dm. The pixels140are supplied with the first power ELVDD and the second power ELVSS. The pixels140as mentioned above control current that is supplied from the first power driver160to the second power driver150via the organic light emitting diode in response to the data signal during the emission period of one frame period.

The first power driver160supplies the first power ELVDD to the pixels140. The first power driver160as mentioned above supplies a high level voltage as the first power ELVDD to be supplied with a second power ELVSS from the second power driver150to the organic light emitting diode.

Meanwhile, according to one embodiment of the present invention, the light emission control line E can be omitted, and the pixels140can be set in the non-light emitting state during the scan period using the first power ELVDD or the second power ELVSS. For example, the pixels140can be set in the non-light emitting state by setting the first power ELVDD to the low level voltage or the second power ELVSS to the high level voltage during the scan period. This will be described in more detail in connection with the structure of the pixels140.

The data processor170classifies the data inputted (or supplied) from outside into 2D or 3D data, and then produces data for additional frame by using the classified data. To achieve this, the data processor170includes a data divider172, a 3D data processor174, a 2D data processor176, and a data transmitter178. In this case, the data processor170changes from i-th (here, i is a natural number) (or first) driving frequency (Hz) to j-th (here, j is a natural number greater than i) (or second) driving frequency (Hz), and then supplies data to the timing controller180. For convenience of explanation, it is assumed that i (or the first driving frequency) is 60 Hz and j (or the second driving frequency) is 120 Hz.

The data divider172distinguishes data inputted from outside system between 2D or 3D data, and supplies the distinguishing data to 3D data processor174or 2D data processor176.

More specifically, the data inputted from the outside includes distinguishing bits for identifying 2D or 3D images. The data divider172distinguishes data images by using the distinguishing bits included in data and supplies data corresponding to 2D images to the 2D data processor176and data corresponding to 3D images to the 3D data processor174.

The 3D data processor174divides (or outputs) a left eye image and right eye image by using data that is inputted (or supplied) to the 3D data processor174. More specifically, the data of 3D image for one frame that is inputted from the data divider172includes the left eye and right eye images. The 3D data processor174produces two frames of data by dividing the left eye (L) image and the right eye (R) image included in one frame as depicted inFIG. 2. In this case, because two frames of data are produced by using one frame of data, the scale-up of the left eye (L) and right eye (R) frame image that are newly produced are improved. Various methods (including, e.g., dithering) that are known can be used as the scale-up method. For example, the scale can be improved by using k (here, k is a natural number) pixel data (it is assumed as the left eye) inputted from the data divider172as k and k+1 pixel data.

The 2D data processor176produces data for two frames by using the data of one frame that is inputted to the 2D data processor176. A 2D data processor176produces the data for two frames by using the data of one frame by using various methods that are now known. For example, the 2D data processor176can add one frame by copying the data of one frame as it is. In addition, the 2D data processor176may produce the additional frame by being inputted (or supplied) two adjacent frames, and changing a part of (or interpolating) data between two frames that are inputted, e.g., by using Motion Estimation Motion Compensation (MEMC).

The data transmitter178transfers Data′ supplied from the 3D data processor174or Data′ supplied from the 2D data processor176to the timing controller180.

The timing controller180transfers Data′ that is supplied to the timing controller180to the data driver120. The timing controller180sets up the width of the scan period (i.e., the non-emission period) of one frame by controlling any one of the drivers among the scan driver110, the second power driver150, and the first power driver160. For example, the timing controller180can set the pixels140in the non-light emitting state during 50% of one frame period.

Meanwhile, for one embodiment of the present invention, the width of the scan period at the timing controller180can be set as various types. For example, the timing controller180can control the width of the scan period corresponding to a signal inputted from user. In other words, when displaying a video, the width of the scan period may be set to be wide, and when displaying a picture, the width of the scan period may be set to be narrow. When displaying a video, as the scan period becomes wider, the image having a little more feeling of movement can be displayed.

The wireless transmitter190transmits a wireless signal corresponding to the scan period of one frame period. The pair of shutter glasses200that receives the wireless signal synchronize the response time thereof with the scan period.

FIG. 3illustrates two frame periods according to an embodiment of the present invention.

Referring toFIG. 3, the organic light emitting display device according to one embodiment of the present invention is driven in the concurrent (or simultaneous) emission method regardless of 2D and 3D (or whether it is displaying 2D or 3D images). Generally, the driving methods are divided into the progressive (or sequential) emission and concurrent (or simultaneous) emission methods. The progressive emission method is to progressively input (or supply) data according to each scan line, and in which pixels progressively emit light in a horizontal line similar to the input order of data (e.g., the pixels emit light one line at a time).

The concurrent (or simultaneous) emission method is to progressively input data according to each scan line, and in which pixels concurrently (or simultaneously) emit light after data is supplied to all the pixels. One frame driven according to one embodiment of the present invention by the concurrent (or simultaneous) emission method is divided into the scan period and an emission period.

The scan period is the period during which the data signals are supplied to each of the pixels140. In other words, the scan signal is progressively supplied to the scan lines S1to Sn during the scan period, and the data signal is supplied to the pixels selected by the scan signal. The pixels140are set in the non-emission state during the scan period as mentioned above.

The emission period is a period in which the pixels140emit light corresponding to the data signal supplied during the scan period.

For the driving method according to one embodiment of the present invention, the pair of 3D shutter glasses (or pair of shutter glasses) display may be easily implemented because the non-emission period (i.e., the scan period) and emission period may be precisely divided.

The pair of 3D shutter glasses displays the left eye image and the right eye image alternately per each frame. A user wears the pair of “shutter glasses” that are switched to 0% and 100% transmittances for the left eye/right eye. The pair of shutter glasses can allow user to recognize (or perceive) an image having a three-dimensional effect by supplying the left eye image to the left eye and the right eye image to the right eye.

When displaying a 2D image using the concurrent (or simultaneous) emission method, an image having more feeling of movement can be displayed by controlling the width of the scan period.

FIG. 4illustrates timing diagrams for driving a pair of 3D shutter glasses according to a progressive emission method.

Referring toFIG. 4, the non-emission period (or section) should be inserted for the response time of the pair of shutter glasses (for example, 2.5 ms) in order to prevent a cross talk phenomenon between images of the left eye/right eye when outputting image in the progressive emission method. In other words, the non-emission section is additionally produced for the response time of the pair of shutter glasses between the frame (i-th frame: i is a natural number) outputting the left eye image and the frame ((i+1)-th frame) outputting the right eye image. For this reason, there is a disadvantage that the emission time rate (or duty ratio) is reduced.

FIG. 5illustrates timing diagrams for driving a pair of 3D shutter glasses in a concurrent (or simultaneous) emission method according to an embodiment of the present invention.

Referring toFIG. 5, when outputting image using the concurrent (or simultaneous) emission method, the emission is concurrently (or simultaneously) performed on the whole of the display unit, and the pixels are set in the non-emission state in the section (or period) except for the emission period. Therefore, the non-emission section between the section outputting the left eye image and the section for outputting the right eye image may be naturally secured.

In other words, the pixels140are set in the non-emission state during the scan period between i-th frame and (i+1)-th frame, and the emission time ratio (or duty ratio) should not be reduced separately, unlike the conventional progressive emission method, by synchronizing the scan period with the response time of the pair of shutter glasses.

FIG. 6Aillustrates a first embodiment of a pixel as depicted inFIG. 1. InFIG. 6A, the pixel coupled to an n-th scan line Sn and an m-th data line (Dm) is depicted for convenience of explanation.

Referring toFIG. 6A, a pixel140according to the first embodiment of the present invention includes the organic light emitting diode (OLED), a first transistor M1, a second transistor M2, and a third transistor M3.

An anode electrode of the organic light emitting diode (OLED) is coupled to a second electrode of the second transistor M2(a driving transistor), and a cathode electrode is coupled to the second power driver for supplying the second power ELVSS. The organic light emitting diode (OLED) as mentioned above produces light having luminance corresponding to current supplied from the second transistor M2.

A gate electrode of the first transistor M1is coupled to the scan line Sn, and a first electrode is coupled to the data line Dm. A second electrode of the first transistor M1is coupled to a first node N1. The first transistor M1as mentioned above is turned on to electrically couple the data line Dm to the first node N1when the scan signal is supplied to the scan line Sn.

A gate electrode of the second transistor M2is coupled to the first node N1, and a first electrode of the second transistor M2is coupled to a second electrode of the third transistor M3. The second electrode of the second transistor M2is coupled to the anode electrode of the organic light emitting diode OLED. The second transistor as mentioned above controls a current that is supplied to the organic light emitting diode OLED in accordance with a voltage supplied to the first node N1.

A first electrode of the third transistor M3(an emission control transistor) is coupled to the first power driver for supplying the first power ELVDD, and a second electrode is coupled to the first electrode of the second transistor M2. A gate electrode of the third transistor M3is coupled to the emission control line E. The third transistor M3as mentioned above is turned on during the period during which the emission control signal is not supplied to the emission control line E. In other words, the third transistor M3is turned on during the emission period and turned off during the scan period.

Meanwhile, the third transistor according to one embodiment of the present invention blocks the electrical connection between the first power driver for supplying the first power ELVDD and the organic light emitting diode OLED during the scan period in order to reduce or substantially prevent current from flowing to the organic light emitting diode OLED. In one embodiment, the third transistor M3as mentioned above may be coupled between the second electrode of the second transistor M2and the anode electrode of the organic light emitting diode OLED as depicted inFIG. 6B.

A storage capacitor Cst is coupled between the gate electrode of the second transistor M2and the anode electrode of the organic light emitting diode OLED. The storage capacitor Cst as mentioned above is charged with voltage corresponding to the data signal.

FIG. 7illustrates a driving method of a pixel as depicted inFIGS. 6A and 6Baccording to one embodiment of the present invention.

Referring toFIG. 7, the scan signal (or scan signals) is supplied to the scan lines S1to Sn during the scan period. The emission control signal is supplied to the emission control line E during the scan period.

When supplying the scan signal to the scan line Sn, the first transistor is turned on. When turning on the first transistor M1, the data line Dm and the first node N1are electrically coupled. The storage capacitor Cst is charged with a voltage corresponding to the data signal. Meanwhile, the third transistor M3is maintained in the turned-off state because the emission control signal is supplied to the emission control line E during the scan period.

The emission control signal is not supplied to the emission control line E during the emission period. When stopping the supply of the emission control signal to the emission control line E, the third transistor M3included in each pixel140is turned on. When turning on the third transistor M3, a current path from the first power driver through the second transistor M2and the organic light emitting diode OLED to the second power driver is formed. At this time, the second transistor M2controls the current that flows to the organic light emitting diode OLED in accordance with the voltage supplied to the first node N1.

InFIG. 6AandFIG. 6B, the pixels140include NMOS transistors M1, M2, and M3, but embodiments of the present invention will not be limited thereto. For example, as depicted inFIGS. 8A and 8B, the transistors M1to M3may be formed as PMOS transistors. In this case, the storage capacitor Cst is formed between the gate electrode of the second transistor M2and the first electrode of the second transistor M2, but otherwise has a substantially similar circuit configuration. When the transistors M1, M2, and M3are PMOS transistors, the polarity of driving waveform is reversed, as depicted inFIG. 9.

FIG. 10illustrates a second embodiment of a pixel as depicted inFIG. 1. ForFIG. 10, the pixel coupled to the n-th scan line Sn and the m-th data line Dm is depicted for convenience of explanation.

Referring toFIG. 10, the pixel140according to the second embodiment of the present invention includes the organic light emitting diode OLED, the first transistor M1, and the second transistor M2.

The anode electrode of the organic light emitting diode OLED is coupled to the second electrode of the second transistor M2, and the cathode electrode is coupled to the second power driver for supplying the second power ELVSS. The organic light emitting diode OLED as mentioned above produces light having luminance corresponding to current supplied from the second transistor M2.

A gate electrode of the first transistor M1is coupled to the scan line Sn, and a first electrode is coupled to the data line Dm. A second electrode of the first transistor M1is coupled to the first node N1. The first transistor M1as mentioned above is turned on when supplying the scan signal to the scan line Sn to electrically couple the data line Dm to the first node N1.

The gate electrode of the second transistor M2is coupled to the first node N1, and the first electrode is coupled to the first power driver supplying the first power ELVDD. The second electrode of the second transistor M2is coupled to the anode electrode of the organic light emitting diode OLED. The second transistor M2as mentioned above controls current that is supplied to the organic light emitting diode OLED in accordance with a voltage supplied to the first node N1.

The storage capacitor Cst is coupled between the gate electrode of the second transistor M2and the anode electrode of the organic light emitting diode OLED. The storage capacitor Cst as mentioned above is charged with a voltage corresponding to the data signal.

FIG. 11Ais a waveform diagram illustrating a driving method of a pixel as depicted inFIG. 10.

Referring toFIG. 11A, the scan signal is progressively supplied to the scan lines S1to Sn during the scan period. The voltage of the first power ELVDD is set at a low level during the scan period.

When supplying the scan signal to the scan line Sn, the first transistor M1is turned on. When the first transistor M1is turned on, the data line Dm and the first node N1are electrically coupled. When the data line Dm and the first node N1are electrically coupled, the data signal is supplied to the first node N1from the data line Dm. The storage capacitor Cst is charged with voltage corresponding to the data signal. Meanwhile, the pixel140is set in the non-emission state because the first power ELVDD is set at the low level voltage during the scan period.

In this case, the second power ELVSS may be set at the high level voltage in order to set the pixel140in the non-emission state during the scan period as depicted inFIG. 6B. In other words, for one embodiment of the present invention, voltage of the first power ELVDD is set at the low level, or voltage of the second power ELVSS is set at the high level, so that the pixel140may be set up in the non-emission state.

The first power ELVDD is set at the high level during the emission period (forFIG. 11B, the voltage of the second power ELVSS is set at the low level). The second transistor M2controls the current that flows to the second power ELVSS via the organic light emitting diode OLED from the first power ELVDD in accordance with the voltage supplied to the first node N1.

Meanwhile, for the embodiment shown inFIG. 10, the transistors M1, M2included in the pixels140are NMOS transistors, but embodiments of the present invention are not limited thereto. For example, the transistors M1, M2may be formed as PMOS transistors, as depicted inFIG. 12. In this case, the storage capacitor Cst is formed between the gate electrode of the second transistor M2and the first electrode of the second transistor M2, and the circuit configuration may be otherwise substantially the same. However, when the transistors M1, M2are formed as PMOS transistors, the polarity of driving waveform is reversed as depicted inFIGS. 13A and 13B.