KR101365856B1 - Organic Light Emitting Display - Google Patents

Abstract

The present invention provides a display device including a plurality of sub pixels arranged in a matrix form on a substrate; One or more monitoring pixels positioned on the display outer substrate to correspond to emission colors of the sub pixels; A power supply unit supplying a voltage and a current to the sub pixel and the monitoring pixel; A data adjusting unit which reads the image data frame stored in the host memory unit in bit units and converts the image data frame into a plurality of subfield units; A display memory unit which stores the image data frame stored in the host memory unit in a plurality of subfields in association with the data adjusting unit; And a sample hold unit for sampling the current supplied to the monitoring pixel and transferring the sampled value to the power supply to adjust the voltage supplied to the sub pixel, wherein the sample hold unit stores the plurality of subfields in the display memory unit. An organic light emitting display device for sampling a current supplied to a monitoring pixel is provided.

OLED display, sample holding part, black time

Description

[0001] The present invention relates to an organic light emitting display,

1 is a schematic circuit diagram of an organic light emitting display device.

FIG. 2 is an exemplary circuit diagram of a subpixel of FIG. 1. FIG.

3 is an exemplary configuration diagram of a data adjusting unit shown in FIG. 1.

4 is an exemplary diagram of a subfield in which black time is interposed.

5 illustrates an example of a data frame converted in units of a plurality of subfields.

6 is a block diagram of a sample hold section.

7 is a diagram illustrating a driving waveform according to a sampling operation of a sample hold unit associated with a display memory unit write process;

8 is another exemplary diagram of a driving waveform according to a sampling operation of a sample hold unit associated with a display memory unit writing process;

9 is an exemplary diagram of a driving waveform according to a sampling operation of a sample hold unit associated with black time interposed in a plurality of subfields.

10 is another exemplary diagram of a driving waveform according to a sampling operation of a sample hold unit associated with black time interposed in a plurality of subfields.

DESCRIPTION OF THE REFERENCE NUMERALS

110: display unit 115: sub pixel

120: monitoring pixel 140: host memory portion

150: data adjustment unit 160: display memory unit

170: control unit 180: power supply unit

190: sample holding part

The present invention relates to an organic light emitting display.

An organic electroluminescent device used in an organic electroluminescent display device is a self-luminous device in which a light emitting layer is formed between two electrodes.

The organic electroluminescent device has a top emission mode and a bottom emission mode depending on a direction in which light is emitted and a passive matrix type and an active matrix type Active Matrix).

Among the organic light emitting display devices, an organic light emitting display device using an active matrix type includes a transistor, a capacitor, and an organic light source positioned inside a subpixel when a scan signal and a data signal are supplied to a plurality of subpixels arranged in a matrix form on a display unit. The light emitting diode is driven to display an image.

Conventional organic light emitting display devices receive data and scan signals from devices positioned outside the panel. Here, the image data supplied from the outside is stored in the host memory, and the data stored in the host memory is arranged in units of frames after the image quality tuning step and supplied to the display unit.

On the other hand, in consideration of the deterioration of devices such as transistors, capacitors, and organic light emitting diodes, the monitoring pixels are provided on the outer substrate of the display unit, and the power supplied to the subpixels located in the display unit is sampled and Accordingly, the power supplied to the subpixel is adjusted to compensate for the changed characteristic of the subpixel.

Here, in the case of the sample holding part sampling the power supplied to the monitoring pixels, it is important to consider driving conditions between devices that interoperate with each other, such as a writing or reading process of the display memory part or a light emitting period or a non-light emitting period of the subpixel.

Accordingly, in order to compensate for the changed characteristics of the subpixel using the monitoring pixel and the sample holding unit, a scheme for improving the efficiency and accuracy of sampling in consideration of various conditions described above should be prepared.

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic light emitting display device capable of reducing the number of display memories required for subfield unit driving and increasing the sampling efficiency and accuracy of monitoring pixels.

The present invention for solving the above problems, the display unit including a plurality of sub-pixels arranged in a matrix form on the substrate; One or more monitoring pixels positioned on the display outer substrate to correspond to emission colors of the sub pixels; A power supply unit supplying a voltage and a current to the subpixel and the monitoring pixel; A data adjusting unit for reading image data frames stored in the host memory unit in units of bits and arranging the units in a plurality of subfields; A display memory unit which stores the image data frame stored in the host memory unit in a plurality of subfields in association with the data adjusting unit; And a sample hold unit for sampling the current supplied to the monitoring pixel and transferring the sampled value to the power supply to adjust the voltage supplied to the sub pixel, wherein the sample hold unit stores the plurality of subfields in the display memory unit. An organic light emitting display device for sampling a current supplied to a monitoring pixel is provided.

When the image data frame is stored in the display memory unit, the data adjusting unit may include increasing the number of subfields and interposing black time in the end section of the increased subfields.

When the monitoring pixel includes red, green, and blue, and there is one current source for supplying current to the monitoring pixel, the sample holding unit may separately sample the red, green, and blue monitoring pixels.

When the monitoring pixel includes red, green, and blue, and three current sources supplying current to the monitoring pixel correspond to the monitoring pixel, the sample holding unit may sample all of the red, green, and blue monitoring pixels in the same interval. .

The sample hold unit may sample the monitoring pixel when the black time interval interposed in the end section of the subfield is supplied to the display unit.

When the data controller writes to store the plurality of subfields in the display memory unit, the display unit may be in a non-display state.

The data adjusting unit includes a look-up table, and the look-up table may increase the number of subfields based on data corresponding to the image data frame and interpose black time in the end section of the increased subfield.

The data adjusting unit may include a subfield arranging unit, and the subfield arranging unit may arrange the subfield including the black time so as to be stored in the display memory unit.

An interval in which black time is interposed may be set to a size greater than 0 and less than 30% of the total interval of one subfield.

The sample hold unit may include two or more switch units, one or more capacitors, and one or more amplifiers.

The subfields may be arranged such that the positions of the least significant bit (LSB) and the most significant bit (MSB) are mixed at least partially.

The subpixel may be an organic light emitting diode connected to a transistor array including one or more capacitors and transistors.

<Example 1>

1 is a schematic circuit diagram of an organic light emitting display device.

Referring to FIG. 1, an organic light emitting display device according to an exemplary embodiment includes a panel that is a display unit 110 including a plurality of sub pixels 115 arranged in a matrix form on a substrate. The sub-pixel 115 is described as one example of emitting red, green, and blue.

And a monitoring pixel 120 positioned on the outer substrate of the display unit 110 to correspond to the emission color of the sub-pixel 115. Since the monitoring pixel 120 is positioned to correspond to the emission color of the sub-pixel 115, the monitoring pixel 120 also emits red, green, and blue as an example.

The power supply unit 180 supplies a voltage to the subpixel 115 and a current to the monitoring pixel 120. The power supply unit 180 supplies a current output from one current source to all the monitoring pixels 120 and corresponds to the monitoring pixel 120, that is, a current output from three current sources is output to each monitoring pixel ( One of the methods of supplying 120 may be adopted.

And a driver 130a or 130b for supplying a data signal and a scan signal to the display unit 110. As illustrated, the drivers 130a and 130b may be divided into a data driver 130a for supplying a data signal to the display 110 and a scan driver 130b for supplying a scan signal to the display 110.

And a host memory unit 140 that stores image data supplied from the outside in units of frames. The host memory unit 140 may be configured as a mass storage device to store a large amount of image data from the outside.

And a display memory unit 160 for storing the image data frame stored in the host memory unit 140 in units of a plurality of subfields and supplying the image data frame to the data driver 130a.

And a data adjusting unit 150 for reading an image data frame stored in the host memory unit 140 in units of bits, converting the image data frame into a plurality of subfield units, and storing the image data frame in the display memory unit 160. In particular, when storing the data in the display memory unit 160 in subfield units, the data adjusting unit 150 increases the number of subfields and intersects the black time in the end section of the increased subfields.

And a sample hold unit 190 for sampling the current supplied to the monitoring pixel 120 and transferring the sampled value to the power supply unit 180 to adjust the voltage supplied to the subpixel 115. Here, the sample holding unit 190 samples the current supplied to the monitoring pixel 120 when the data adjusting unit 150 writes to store the plurality of subfields in the display memory unit 160.

In addition, a controller for supplying a control signal to the host memory 140, the data controller 150, the display memory 160, the drivers 130a and 130b, the power supply unit 180, and the sample hold unit 190 described above ( 170). The controller 170 generates and outputs a control signal so that each device can be interlocked and controlled organically.

Hereinafter, the circuit configuration of the subpixel 115 shown in FIG. 1 will be described in more detail with reference to FIG. 2.

FIG. 2 is an exemplary circuit diagram of a subpixel of FIG. 1.

The circuit diagram of the subpixels illustrated in FIG. 2 is only an example of a circuit diagram for better understanding of the description, and the present disclosure is not limited thereto.

As illustrated in FIG. 2, the subpixel includes a switching transistor TFT1 having a gate connected to the scan line SCAN and a first electrode connected to the data line DATA in common. In addition, the driving transistor TFT2 includes a gate connected to the second electrode of the switching transistor TFT1 and a first electrode connected to the first power line VDD. In addition, the capacitor C may be connected between the gate of the driving transistor TFT2 and the first power line VDD. In addition, the organic light emitting diode D may include an organic light emitting diode D connected between the second electrode of the driving transistor TFT2 and the second power line GND.

Here, the organic light emitting diode D may be an organic light emitting diode in which the light emitting layer is formed of an organic material layer, but may also be an inorganic light emitting diode in which the light emitting layer is formed of an inorganic material layer.

In addition to the description of the structure of the organic light emitting diode (D), the organic light emitting diode (D) is common, such as a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL) and an electron injection layer (EIL) The organic light emitting layer (EML) is interposed between the film. In general, the common film is selectively formed between the first electrode (pixel electrode) and the cathode of the driving transistor TFT2 serving as the anode electrode.

On the other hand, the power wiring of each subpixel may be connected to a power supply so as to be distinguished from each other, and may receive an independent voltage, that is, a different voltage. The transistors TFT1 and TFT2 included in each subpixel may be driven in the linear region or the saturation region by the driving signal supplied from the driver as described above. It is advantageous to adopt a digital driving method for driving the TFT2) in the linear region. Here, the digital driving method refers to a method of simply turning on or off a transistor.

Although not shown, the monitoring pixel shown in FIG. 1 may be formed in the same configuration as the above-described subpixel, but it is advantageous that the monitoring pixel of the present invention adopts a simple configuration including one capacitor and an organic light emitting diode. Do.

Hereinafter, the data adjusting unit 150 shown in FIG. 1 will be described in more detail with reference to FIG. 3.

3 is an exemplary configuration diagram of a data adjusting unit shown in FIG. 1.

Exemplary diagrams of the data adjusting unit shown in FIG. 3 are provided only for better understanding of the description, and the present invention is not limited thereto.

As illustrated in FIG. 3, the data adjusting unit 150 includes a gamma unit 151 for importing an image data frame stored in the host memory unit 140 in units of bits. The gamma unit 151 adjusts luminance values of gray (R), green (G), and blue (B) image data frames, which are input through a pre-stored gamma data conversion system, to a gray level suitable for image implementation of the organic light emitting display device. Convert

On the other hand, the gamma unit 151 increases the number of subfields based on data corresponding to the input image data frame using a look-up table included in the gamma conversion. Black time may be interposed at the end of the field.

4 is an exemplary diagram of a subfield in which black time is interposed.

Referring to FIG. 4 to help understand the description, it can be seen that one image data frame (1 frame) divided into a plurality of subfields has black time BT interposed in the end section of the subfield. Detailed description thereof will be described below.

As described above, the data in the gamma-converted subfield unit may pass through the halftone unit 153 to fine-tune an image converted in the subfield unit, that is, to perform image dithering, as shown.

The data adjusting unit 150 includes a subfield arranging unit 155. The subfield arranging unit 155 performs an arrangement to store data in a subfield unit including black time in the display memory unit 160. Of course, the rearrangement may be performed to supply the data in the subfield unit stored in the display memory unit 160 to the display unit 110 through the data driver 130a. Here, the process of rearranging data in units of subfields may be required according to an output requirement of the data driver 130a.

The data in the subfield units arranged as described above are stored in the display memory unit 160 and then supplied to the display unit 110 through the data driver 130a. Then, the display unit 110 may implement an image according to the supplied signal.

In this process, the display memory unit 160 writes the image data frame stored in the host memory unit 140 by the data adjusting unit 150 in units of bits and stores them in units of a plurality of subfields. The read step of reading the subfields stored in the unit 160 by the data driver 130a is alternately performed. However, when the display memory unit 160 writes to store the plurality of subfields, the display unit 110 is in a non-display state.

Meanwhile, in the above description, the lookup table has been described as interlocking with the gamma unit 151. However, this is merely an example of an embodiment, and the lookup table does not work together with the gamma unit 151, and the data tabled to correspond to the image data frame. Of course, it can be performed based on.

When the image data frame is read in units of bits from the host memory unit 140, the table is loaded by increasing the units of bits. That is, assuming that the image data frame is loaded in 6-bit units according to the conventional method, it is advantageous in the present invention to load the image data frame in 8 bits or more so as to increase the number of subfields.

If the description is added with reference to the number of subfields, when the number of subfields is increased, the data adjusting unit 150 interposes black time in a section in which the number of subfields is increased to one or more.

Meanwhile, when the image data frame is stored in the display memory unit 160 in units of 6 bits, the subfield is divided into 16 subfields and stored. However, when the image data frame is stored in the display memory unit 160 with 8 bits or more, the subfields can be divided into 28 or more subfields. The increase in the number of subfields is to prevent the phenomenon of overlapping with the subfields stored in the display memory unit 160 in the future by intervening black time. This is equivalent to putting a distinction between the current data and the next data.

For reference, it is advantageous to use a high frequency when writing or reading the display memory unit 160 by increasing the number of subfields, and the number of bits and the number of subfields are not limited to those described.

Hereinafter, the subfield adjusted through the data adjusting unit 150 will be described in more detail with reference to FIG. 5.

5 illustrates an example of a data frame converted in units of a plurality of subfields.

Referring to FIG. 5, it is assumed that one image data frame (1 frame) is divided into 28 subfields SF1..SF28 as an example of description of a plurality of subfields. As described above, each of the first half of the 28 subfields (SF1..SF25) is divided into an address section and a light emission section. In addition, black time (BT) is interposed in the last section (eg, SF26, SF27, SF28).

Here, the illustrated image data frame 1 frame does not represent a form stored in the display memory unit described above. However, in order to help the understanding of the description is shown in a standard form, which is arranged to be supplied to the display unit.

As described above, when a scan signal is supplied to an address section belonging to one subfield, a data frame adjusted in units of a plurality of subfields selects a subpixel to emit light, and when a data signal is supplied to the selected subpixel, organic light emission is performed. The diode will emit light.

On the other hand, the light emission period is a period for determining the gray scale weight in each subfield. For example, the gray scale weight of each subfield is 2 ⁿ by setting the gray scale weight of the first subfield SF1 to 2 ⁰ and the gray scale weight of the second subfield to 2 ¹ . The gray scale weight of each subfield may be determined to increase at a ratio of 0, 1, 2, 3, 4, and 5).

As described above, in the light emitting period of each subfield, the gray scale for various images can be realized by adjusting the light emission holding time of each subfield according to the gray scale weight. However, the gray scale weight described above is just an example.

For reference, since the least significant bit of the subfield has a short emission time, an erasing section for erasing the emission time may be inserted. In the erase period, light emission of the organic light emitting diode is stopped by discharging the data signal stored in the capacitor of the subpixel.

The black time BT interposed at the end of the subfield does not represent an image unlike an address section and a light emission section. That is, it becomes a non-display section state.

Therefore, when the black time (BT) section is interposed at the end of the subfield, it is advantageous to set the size to more than 0 and 30% or less of the total section of one subfield. Here, the ideal size of the black time BT period may be about 5% or more and 15% or less.

This is because when the period in which the black time BT is interposed is set to 5% to 15%, the display memory can be read and written with a fast frequency clock when the display memory is accessed.

Meanwhile, the above-described subfields may be arranged such that the positions of the LSB and the Most Significant Bit (MSB) are partially mixed. This is to prevent the phenomenon that the optical center is focused on a specific area when the image data frame (1 frame) is divided into a plurality of subfields, and the light emitting period of the subfields is longer toward the rear.

In addition to this description, if the MSB of the previously input data emits a long light and the LSB of the next incoming data emits a short light, there is a possibility that the sense of vision may be degraded. It will be appreciated that it is advantageous to locate the various mixtures.

Hereinafter, the description will be given in detail with reference to FIG. 6.

6 is a block diagram of a sample hold unit.

Referring to FIG. 6, when the power supply unit 180 supplies a current to the monitoring pixel 120, the sample hold unit samples the supplied current Im as a voltage to feed back a sampling value to the power supply unit 180. Pass by signal. Then, the power supply unit 180 adjusts the voltage Vm to be supplied to the subpixel 115 with reference to the sampling value.

As such, the sample holding unit may include two or more switch units, one or more capacitors, and one or more amplifiers to sample the current supplied to the monitoring pixel 120 with a voltage and transfer the sampled value to the power supply unit 180. .

In more detail, one of the two or more switch units included in the sample holding unit 190 is positioned on a power line connecting the power supply unit 180 and the monitoring pixel 120 to supply current to the monitoring pixel 120. The switching operation is performed so that (Im) is supplied. The other is connected to the power line of the monitoring pixel 120 to sample the current Im supplied to the monitoring pixel 120. In this case, the sampled current Im is held as a voltage in the capacitor, and the held voltage is transferred to the power supply unit 180 as a feedback FB signal through an amplifier. Then, the power supply unit 180 adjusts the voltage to be supplied to the subpixel 115 with reference to this.

On the other hand, the organic light emitting display device according to an embodiment of the present invention is supplied to the monitoring pixel when the sample holding unit writes the data adjusting unit to store the plurality of subfields in the display memory in the series of driving processes described above. Sample the current.

Hereinafter, referring to FIGS. 7 and 8, when a display memory unit writes to store a subfield, two types of current sources included in the power supply unit and three cases are supplied to the monitoring pixel. Sampling to supply current will be described.

7 is a diagram illustrating a driving waveform according to a sampling operation of a sample hold unit associated with a display memory unit writing process.

7 is an exemplary view assuming that there is only one current source included in the power supply unit.

Referring to FIG. 7, in the memory writing time MWT, which is a period in which the display memory unit MM writes, the sample holding unit red monitoring pixel MR, green monitoring pixel MG, and blue monitoring pixel MB. You can see that each sample separately).

In general, when there is only one current source included in the power supply unit, one current source needs to perform time division switching or use a current divider to supply different currents to each of the monitoring pixels MR, MG, and MB. Sampling should be done separately.

8 is another exemplary diagram of a driving waveform according to a sampling operation of a sample hold unit associated with a display memory unit writing process.

The sampling driving waveform of FIG. 8 is an exemplary diagram assuming three current sources included in the power supply unit.

Referring to FIG. 8, in the memory writing time MWT, which is a period in which the display memory unit MM performs a write operation, the sample hold unit is a red monitoring pixel MR, a green monitoring pixel MG, and a blue monitoring pixel MB. It can be seen that both are sampled in the same interval.

In general, if the current source included in the power supply unit matches the number of monitoring pixels, the three current sources can supply different currents to all the monitoring pixels MR, MG, and MB at the same time. Sampling can be performed.

The sampling method shown in Figs. 7 and 8 shows different sampling waveforms depending on whether there is only one current source or correspondingly located to the monitoring pixel, but their ultimate purpose is to select a sample value when the current is supplied to the monitoring pixel. This is to ensure accurate acquisition.

The writing process of writing to store a plurality of subfields in the display memory unit is a very short time, but this section is a non-display state in which the display unit does not display an image as described above.

Accordingly, when the sample holding unit samples the current supplied to the monitoring pixel, the sample acquisition error is caused by a phenomenon in which the ground caught on the second power supply line GND of the display device as a whole is shaken while the display unit overlaps the section displaying the image. The problem can be solved.

That is, when the display unit emits light, the capacitor included in the sample hold part may escape the error of obtaining a low sample value by increasing the ground voltage. This occurs because all of the second power lines GND in the display device are commonly tied. Although this can be solved structurally, the driving method of the present invention can reduce the number of display memories required for the subfield unit driving. The effect is to reduce and increase the sampling efficiency and accuracy of the monitoring pixels.

On the other hand, the organic light emitting display device according to an embodiment of the present invention samples the current supplied to the monitoring pixel when the data controller writes to store the plurality of subfields in the display memory unit. Here, in particular, the plurality of subfields are interposed through black time. Then, the display unit is in a non-display state in the section where the black time is supplied.

Therefore, in the present invention, the section for sampling the sample holding unit is possible not only when the display memory unit performs the writing process but also in the section where the black time is supplied.

9 and 10, a plurality of subfields including black time are divided into frames and sampling is performed for every n frames, but the case where one current source is included in the power supply unit is described. The sampling of supplying the current supplied to the monitoring pixel will be described by dividing the two cases in the example into embodiments.

9 illustrates an example of a driving waveform according to a sampling operation of a sample hold unit associated with black time interposed in a plurality of subfields.

9 is an exemplary view assuming that there is only one current source included in the power supply unit.

Referring to FIG. 9, the black time BT positioned at the end of the last frame N frames among two consecutive frames FR interposed with the black time BT in the plurality of subfields SF. For example, it may be appreciated that the sample holding unit separately classifies and samples the red monitoring pixel MR, the green monitoring pixel MG, and the blue monitoring pixel MB.

That is, the sample hold unit samples the current of the monitoring pixel in the black time BT section positioned at the end of every two or more frames (N-1 frame, N frames). However, at this time, of course, the current source can be applied to three cases instead of one.

10 is another exemplary diagram of a driving waveform according to a sampling operation of a sample hold unit associated with black time interposed in a plurality of subfields.

The sampling driving waveform of FIG. 10 is an exemplary diagram assuming three current sources included in the power supply unit.

Referring to FIG. 10, a black time located between two consecutive frames N-1 frame and N frame among a plurality of frames FR in which a plurality of subfields SF intersects a black time BT. BT, it can be seen that the sample holding unit separately distinguishes and samples the red monitoring pixel MR, the green monitoring pixel MG, and the blue monitoring pixel MB.

That is, the sample holding unit samples the current of the monitoring pixel in the black time BT section positioned at the end of every frame (N-1 frame, N frame). However, at this time, it is a matter of course that the current source is applicable to one case instead of three.

As described above, the present invention reduces the number of display memories required for subfield unit driving, and considers various conditions in terms of sampled values and efficiency when sampling current supplied to a monitoring pixel using a sample hold unit. Thus, even when there is a fluctuation or noise in the ground level, the current flowing through the monitoring pixel can be accurately obtained as a voltage, and the voltage to be supplied to the subpixel can be adjusted based on this.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the above-described technical configuration of the present invention may be embodied by those skilled in the art to which the present invention pertains without changing the technical spirit or essential features of the present invention. It will be appreciated that the present invention may be practiced as. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

As described above, the present invention has an effect of providing an organic light emitting display device capable of reducing the number of display memories required for subfield unit driving and increasing the sampling efficiency and accuracy of monitoring pixels.

Claims (12)

A display unit including a plurality of sub pixels arranged in a matrix form on a substrate; At least one monitoring pixel positioned on the display outer substrate to correspond to the emission color of the sub pixel; A power supply unit supplying a voltage and a current to the subpixel and the monitoring pixel; A host memory unit which stores image data supplied from the outside in units of frames; A data adjusting unit which reads the image data frame stored in the host memory unit in bit units and converts the image data frame into a plurality of subfield units; A display memory unit for storing image data frames stored in the host memory unit in units of the plurality of subfields in association with the data adjusting unit; And And a sample hold part for sampling the current supplied to the monitoring pixel and transferring the sampled value to the power supply to adjust the voltage supplied to the sub pixel. And the sample hold unit samples the current supplied to the monitoring pixel when the data adjusting unit writes to store the plurality of subfields in the display memory unit. The method of claim 1, The data adjustment unit, And storing the image data frame in the display memory unit, increasing the number of the subfields and interposing the black time in the end section of the increased subfields. 3. The method of claim 2, The monitoring pixel comprises red, green and blue, When there is only one current source for supplying current to the monitoring pixel, And the sample hold part separately samples the red, green, and blue monitoring pixels. 3. The method of claim 2, The monitoring pixel comprises red, green and blue, When there are three current sources for supplying current to the monitoring pixel to correspond to the monitoring pixel, The sample hold unit is configured to sample all of the red, green, and blue monitoring pixels in the same section. The method according to claim 3 or 4, And the sample hold unit samples the monitoring pixel when the black time interval interposed in the end section of the subfield is supplied to the display unit. The method of claim 1, And the display portion is in a non-display state when the data adjusting portion writes to store the plurality of subfields in the display memory portion. 3. The method of claim 2, The data adjustment unit includes a look-up table, Wherein the look-up table increases the number of the subfields based on data corresponding to the image data frame and intersects black time in the end section of the subfield. 3. The method of claim 2, The data adjusting unit includes a subfield arranging unit, And the subfield arranging unit arranged to store the subfield including the black time in the display memory unit. 3. The method of claim 2, The section in which the black time is interposed, An organic light emitting display device which is set to a size greater than 0 and less than 30% of a total section of one subfield. The method of claim 1, The sample hold portion, An organic light emitting display device comprising at least two switch units, at least one capacitor, and at least one amplifier. The method of claim 1, The subfield is, Organic light emitting display device arranged such that at least a portion of LSB (Least Significant Bit) and MSB (Most Significant Bit) are mixed. The method of claim 1, The sub- An organic light emitting display device in which an organic light emitting diode is connected to a transistor array including at least one capacitor and a transistor.

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