KR102653577B1 - Organic Light Emitting Display Device And Pixel Compensating Method Of The Same - Google Patents

Abstract

An organic light emitting display device according to an embodiment of the present invention includes a display panel in which a plurality of pixels are arranged in each of a plurality of display areas; and dividing the display areas into a specific display area in which a specific data pattern is displayed and a normal display area in which a normal data pattern other than the specific data pattern is displayed, and first sensing the driving characteristics of pixels arranged in the specific display area. It includes a timing controller that differently controls a compensation period and a second sensing & compensation period for driving characteristics of pixels arranged in the normal display area.

Description

Organic Light Emitting Display Device And Pixel Compensating Method Of The Same}

The present invention relates to organic light emitting display devices, and more particularly to organic light emitting display devices and pixel compensation methods thereof.

The active matrix type organic light emitting display device includes an organic light emitting diode (hereinafter referred to as “OLED”) that emits light on its own, and has the advantages of fast response speed, high luminous efficiency, brightness, and viewing angle.

An organic light emitting display device arranges pixels, each including OLED, in a matrix form and adjusts the luminance of the pixels according to the gradation of image data. Each pixel includes a driving element, that is, a driving TFT (Thin Film Transistor), that generates a pixel current applied to the OLED according to the voltage applied between the gate electrode and the source electrode. The driving characteristics of OLED and driving TFT change depending on temperature or deterioration. If the driving characteristics of the OLED and/or the driving TFT change, the luminance between pixels varies even if the same image data is written, making it difficult to implement the desired image.

External compensation techniques are known to compensate for changes in driving characteristics of these pixels. External compensation technology senses changes in pixel driving characteristics and corrects image data based on the sensing results.

The organic light emitting display device senses pixels by operating the sensing unit at preset specific times, and after sensing for all pixels is completed, compensation values for correcting image data are updated. In order to quickly compensate for changes in driving characteristics of pixels, the update cycle of compensation values (hereinafter referred to as compensation cycle) must be short. This compensation period is closely related to the sensing time for pixels. If the sensing time for pixels is long, the compensation cycle also becomes longer. However, in certain data patterns that cause temperature increases or short-term afterimages, the driving characteristics of pixels change faster than the predetermined compensation period, which may deteriorate real-time compensation performance.

Accordingly, the present invention provides an organic light emitting display device and a pixel compensation method thereof that can increase luminance uniformity between one specific display area and other display areas of a display panel where a specific data pattern is displayed.

An organic light emitting display device according to an embodiment of the present invention includes a display panel in which a plurality of pixels are arranged in each of a plurality of display areas; and dividing the display areas into a specific display area in which a specific data pattern is displayed and a normal display area in which a normal data pattern other than the specific data pattern is displayed, and first sensing the driving characteristics of pixels arranged in the specific display area. It includes a timing controller that differently controls a compensation period and a second sensing & compensation period for driving characteristics of pixels arranged in the normal display area.

The present invention makes the sensing & compensation period for a specific display area where a specific data pattern is displayed shorter than the sensing & compensation period for other display areas. The present invention improves sensing and compensation performance across the entire display screen by shortening the update cycle of the compensation value for a specific display area where the driving characteristics of pixels change relatively quickly compared to that of a normal display area where the driving characteristics of pixels change relatively slowly. Brightness uniformity can be dramatically improved.

Meanwhile, even within a specific display area where a fixed pattern is displayed, the driving characteristics of pixels change relatively faster in the area with the worst color pattern. The present invention reduces the luminance deviation due to the difference in deterioration rate within a specific display area by making the sensing & compensation cycle of pixels displaying a worst color pattern in a specific display area shorter than the sensing & compensation cycle of pixels displaying a single color pattern. can be compensated effectively.

The effects according to the present invention are not limited to the contents exemplified above, and further various effects are included in the present specification.

1 is a diagram showing an organic light emitting display device according to an embodiment of the present invention.
Figure 2 is a diagram showing a plurality of pixels sharing the same sensing line.
Figure 3 is a diagram showing a connection configuration of pixels constituting a pixel array.
FIG. 4 is a diagram showing a configuration of a source drive integrated circuit connected to the pixel array of FIG. 3.
Figures 5 and 6 are diagrams showing examples of sensing units.
Figures 7 and 8 are diagrams showing a full sensing method targeting all pixel lines regardless of data patterns as a comparative example of the present invention.
Figures 9 and 10 are diagrams showing, as an embodiment of the present invention, a full sensing method for all pixel lines and a partial sensing method for some pixel lines are used in parallel according to a data pattern.
Figure 11 is a diagram showing an example of a fixed pattern.
FIG. 12 corresponds to FIGS. 7 and 8 and shows that the sensing and compensation cycles are the same in areas displaying specific data patterns and normal data patterns.
FIG. 13 corresponds to FIGS. 9 and 10 and shows that the sensing & compensation cycles are different in areas displaying specific data patterns and normal data patterns.

The advantages and features of the present specification and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below and will be implemented in various different forms, but the present embodiments only serve to ensure that the disclosure of the present specification is complete, and that common knowledge in the technical field to which this specification pertains is provided. It is provided to fully inform those who have the scope of the invention, and this specification is only defined by the scope of the claims.

The shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining the embodiments of the present specification are illustrative, and the present specification is not limited to the matters shown. When 'includes', 'has', 'consists of', etc. mentioned in the specification are used, other parts may be added unless '~ only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship between two parts is described as 'on top', 'on top', 'at the bottom', 'next to ~', 'right next to' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

First, second, etc. may be used to describe various components, but these components are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical idea of the present specification.

Like reference numerals refer to substantially like elements throughout the specification.

In this specification, the pixel circuit and the gate driver formed on the substrate of the display panel may be implemented as a TFT with an n-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor) structure, but are not limited to this and may also be implemented as a TFT with a p-type MOSFET structure. there is. TFT is a three-electrode device including a gate, source, and drain. The source is an electrode that supplies carriers to the transistor. Within the TFT, carriers begin to flow from the source. The drain is the electrode through which carriers go out of the TFT. That is, the flow of carriers in the MOSFET flows from the source to the drain. In the case of n-type TFT (NMOS), because the carriers are electrons, the source voltage has a lower voltage than the drain voltage to allow electrons to flow from the source to the drain. Since electrons flow from the source to the drain in an n-type TFT, the direction of current flows from the drain to the source. On the other hand, in the case of p-type TFT (PMOS), since the carrier is a hole, the source voltage is higher than the drain voltage so that holes can flow from the source to the drain. In a p-type TFT, current flows from the source to the drain because holes flow from the source to the drain. It should be noted that the source and drain of the MOSFET are not fixed. For example, the source and drain of a MOSFET can change depending on the applied voltage. Accordingly, in the description of the embodiments of the present specification, one of the source and the drain is described as the first electrode, and the other one of the source and the drain is described as the second electrode.

Hereinafter, embodiments of the present specification will be described in detail with reference to the attached drawings. In the following embodiments, the description will focus on an organic light emitting display device including an organic light emitting material. However, it should be noted that the technical idea of the present specification is not limited to organic light emitting display devices, but can be applied to inorganic light emitting display devices including inorganic light emitting materials.

In the following description, if it is determined that a detailed description of a known function or configuration related to the present specification may unnecessarily obscure the gist of the present specification, the detailed description will be omitted.

1 is a diagram showing an organic light emitting display device according to an embodiment of the present invention. Figure 2 is a diagram showing a plurality of pixels sharing the same sensing line. And, Figure 3 is a diagram showing a connection configuration of pixels constituting a pixel array.

1 to 3, an organic light emitting display device according to an embodiment of the present invention may include a display panel 10, a timing controller 11, a data driving circuit 12, and a gate driving circuit 13. there is. The sensing circuit (see 20 in FIG. 4) may be built into the data driving circuit 12.

In the display panel 10, a plurality of data lines 14A and sensing lines 14B and a plurality of gate lines 15 intersect, and pixels P are arranged in a matrix form in each intersection area. Construct a pixel array. Each gate line 15 includes a plurality of first gate lines 15A to which a scan control signal is supplied and a plurality of second gate lines 15B to which a sensing control signal is supplied, as shown in FIG. 3. can do. The scan control signal and the sensing control signal may have the same phase or different phases. When the scan control signal and the sensing control signal have the same phase, the first and second gate lines 15A and 15B can be unified into one gate line 15.

Each pixel P may be connected to one of the data lines 14A, one of the sensing lines 14B, and one of the gate lines 15. The pixels (P) constituting the pixel array include a plurality of red pixels (PR) to display red, a plurality of green pixels (PG) to display green, and a plurality of green pixels (PG) to display blue, as shown in FIG. 2. It may include blue pixels (PB), and may further include a plurality of white pixels (PW) to display white. Four pixels including a red pixel (PR), a green pixel (PG), a blue pixel (PB), and a white pixel (PW) may form one pixel unit (UPXL) as shown in FIG. 3 . However, the configuration of the pixel unit (UPXL) is not limited to this, and may consist of only red pixels (PR), green pixels (PG), and blue pixels (PB) excluding the white pixels (PW). To simplify the configuration of the pixel array, a plurality of pixels (PR, RG, PB, PW) constituting the same pixel unit (UPXL) may share one sensing line (14B). This sensing line sharing structure can reduce the number of sensing lines 14B in the pixel array, helping to improve product yield. In addition, the number of sensing channel terminals of the data driving circuit 12 connected to each sensing line 14B can be reduced, which has the effect of reducing the chip size and manufacturing cost of the data driving circuit 12. However, the technical idea of the present invention is applicable even when a plurality of pixels (PR, RG, PB, PW) constituting the same pixel unit (UPXL) are independently connected to different sensing lines (14B). Each of the pixels P can receive a high-potential pixel voltage (EVDD) and a low-potential pixel voltage (EVSS) from the power generator.

One pixel (P) of the present invention may include an OLED, a driving TFT (DT), a storage capacitor (Cst), a first switch TFT (ST1), and a second switch TFT (ST2) as shown in FIG. 3. It is not limited. This pixel (P) structure can be equally applied to pixels (PR, RG, PB, and PW). TFTs may be implemented as a P type, an N type, or a hybrid type combining the P type and the N type. Additionally, the semiconductor layer of the TFT may include amorphous silicon, polysilicon, or oxide.

OLED includes an anode electrode connected to a source node (Ns), a cathode electrode connected to an input terminal of a low-potential pixel voltage (EVSS), and an organic compound layer located between the anode electrode and the cathode electrode. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer. EIL) may be included.

The driving TFT (DT) generates current between source and drain (hereinafter referred to as pixel current) according to the voltage between gate and source. The amount of light emitted by OLED is determined by the size of this pixel current. The driving TFT (DT) includes a gate electrode connected to the gate node (Ng), a first electrode connected to an input terminal of the high-potential pixel voltage (EVDD), and a second electrode connected to the source node (Ns). The storage capacitor (Cst) is connected between the gate node (Ng) and the source node (Ns) to maintain the gate-source voltage of the driving TFT (DT) for a certain period of time. The first switch TFT (ST1) turns on/off the electrical connection between the data line (14A) and the gate node (Ng) according to the scan control signal. The first switch TFT (ST1) includes a gate electrode connected to the first gate line 15A, a first electrode connected to the data line 14A, and a second electrode connected to the gate node Ng. The second switch TFT (ST2) turns on/off the electrical connection between the source node (Ns) and the sensing line (14B) according to the sensing control signal. The second switch TFT (ST2) includes a gate electrode connected to the second gate line 15B, a first electrode connected to the sensing line 14B, and a second electrode connected to the source node Ns.

Organic light emitting display devices with such pixel arrays employ external compensation technology. External compensation technology is a technology that senses the driving characteristics of the OLED and/or the driving TFT (DT) provided in the pixels (P) and corrects the input image data (IDATA) according to the sensed value (SDATA). The driving characteristics of the OLED refer to the operating point voltage of the OLED, and the driving characteristics of the driving TFT refer to the threshold voltage of the driving TFT and the electron mobility of the driving TFT.

The organic light emitting display device of the present invention performs image display operations and sensing operations. The sensing operation may be performed in a vertical blank period or a vertical active period during an image display operation, in a power-on sequence period before image display begins, or in a power-off sequence period after image display ends. The vertical blank period is a period in which corrected image data (CDATA) is not written, and is disposed between vertical active sections in which one frame of corrected image data (CDATA) is written. The power-on sequence period refers to the period from when the module power is turned on until the screen of the display panel 10 is turned on. The power-off sequence period refers to the period from when the screen of the display panel 10 is turned off until the module power is turned off.

The timing controller 11 operates the data driving circuit 12 based on timing signals such as the vertical synchronization signal (Vsync), the horizontal synchronization signal (Hsync), the dot clock signal (DCLK), and the data enable signal (DE). A data timing control signal (DDC) for controlling the timing and a gate timing control signal (GDC) for controlling the operation timing of the gate driving circuit 13 are generated. The timing controller 11 may generate different timing control signals (DDC, GDC) for an image display operation and timing control signals (DDC, GDC) for a sensing operation.

The gate timing control signal (GDC) includes a gate start pulse (GSP), a gate shift clock (GSC), etc. The gate start pulse (GSP) is applied to the gate stage that generates the first gate signal (including the scan control signal and the sensing control signal) and controls the gate stage so that the first gate signal is output. The gate shift clock (GSC) is a clock signal commonly input to the gate stages and is a clock signal for shifting the gate start pulse (GSP).

The data timing control signal (DDC) includes a source start pulse (Source Start Pulse, SSP), a source sampling clock (SSC), and a source output enable signal (Source Output Enable, SOE). The source start pulse (SSP) controls the data sampling start timing of the data driving circuit 12. The source sampling clock (SSC) is a clock signal that controls the sampling timing of the corrected image data (CDATA) in the data driving circuit 12 based on the rising or falling edge. The source output enable signal (SOE) controls the output timing of the data driving circuit 12.

The timing controller 11 operates the data driving circuit 12, the gate driving circuit 13, and the sensing circuit 20 at preset specific times (vertical blank period, vertical active period, power-on sequence period, or power-off sequence period). By operating, the driving characteristics of the pixels (P) are sensed. The timing controller 11 receives a digital sensing value (SDATA) from the sensing circuit 20 during a sensing operation. The timing controller 11 calculates compensation values that can correct the input image data (IDATA) based on the digital sensing value (SDATA) and updates these compensation values in the memory 16.

The timing controller 11 calculates the corrected image data CDATA by correcting the input image data IDATA to be written as pixels P with the compensation values of the pixels P stored in the memory 16. The corrected image data (CDATA) is transmitted to the data driving circuit 12. By this data correction operation, the driving deviation of the driving TFT (DT) between the pixels (P) may be compensated, or the driving deviation of the OLED between the pixels (P) may be compensated.

The timing controller 11 controls the display panel ( The display areas in 10) are divided into a specific display area and a normal display area. The specific display area is an area where a specific data pattern that causes the driving characteristics of the pixels P to change relatively quickly is displayed. The normal display area is an area where normal data patterns other than specific data patterns are displayed. The normal data pattern causes the driving characteristics of the pixels (P) to change relatively slowly compared to the specific data pattern.

The timing controller 11 controls the operations of the data driving circuit 12, the gate driving circuit 13, and the sensing circuit 20 to determine a first sensing & compensation cycle for the driving characteristics of pixels arranged in a specific display area. The second sensing and compensation cycle for the driving characteristics of the pixels arranged in the normal display area is varied. That is, while the timing controller 11 senses and compensates for the driving characteristics of pixels placed in the normal display area once, the timing controller 11 senses and compensates for the driving characteristics of pixels placed in a specific display area K times (K is a natural number of 2 or more). Control as much as possible. The timing controller 11 can significantly increase real-time compensation performance and improve image quality uniformity by reducing the sensing and compensation cycle in at least one specific area of the display panel where a specific image pattern is displayed compared to other areas.

The data driving circuit 12 is connected to the data lines 14A of the display panel 10 through data channel terminals. The sensing channel terminals connect the sensing circuit built in the data driving circuit 12 and the sensing lines 14B of the display panel 10 to each other. In the sensing line sharing structure, the number of sensing channel terminals is less than the number of data channel terminals. However, in the sensing line independent structure, the number of sensing channel terminals is the same as the number of data channel terminals. Considering the improvement in yield of the pixel array, a shared sensing line structure is more preferable than a sensing line independent structure.

FIG. 4 is a diagram showing a configuration of the data driving circuit 12 connected to the pixel array of FIG. 3. And, Figures 5 and 6 are diagrams showing examples of the sensing unit.

Referring to FIG. 4, the data driving circuit 12 includes a plurality of data channel terminals (DCH), a plurality of digital-to-analog converters (DAC), and sensing channel terminals (SCH). Data channel terminals (DCH) connect digital-to-analog converters (DAC) to data lines 14A of the display panel 10. Digital-to-analog converters (DACs) convert corrected image data (CDATA) into digital-to-analog for image display operations and generate data voltages for image display corresponding to image gradation. Digital-to-analog converters (DACs) generate a sensing data voltage set to a certain size for sensing operations. The data voltage for sensing can be preset to a different size for each color, taking into account that the current capacity of the driving TFT and the luminous efficiency of the OLED are different for each color of the pixel.

Sensing channel terminals (SCH) connect the sensing lines 14B of the display panel 10 to the sensing circuit 20. Pixel currents flowing through the pixels P in response to the sensing data voltage are applied to the sensing circuit 20 through the sensing lines 14B and the sensing channel terminals SCH.

The sensing circuit 20 may be built into the data driving circuit 12. Meanwhile, the sensing circuit 20 may be mounted on a readout integrated circuit outside the data driving circuit 12. When the sensing circuit 20 is mounted on a readout integrated circuit, the data driving circuit 12 is simplified, which has the advantage of increasing the process margin of the data driving circuit 12.

The sensing circuit 20 senses the driving characteristics of the pixels P disposed on the pixel lines Li to Li+3 of the display panel 10 on a pixel line basis based on the data control signal DDC. A pixel line is not a physical signal line, but rather a collection of neighboring pixels (P). The sensing circuit 20 supplies an initialization voltage (Vref or Vpre) to the sensing line 14B, or samples the analog sensing value (electrical characteristic value for the OLED or driving TFT) input through the sensing line 14B. A digital sensing value (SDATA) can be generated. The sensing circuit 20 may be implemented as a voltage sensing type as shown in FIG. 5 or as a current sensing type as shown in FIG. 6 .

The voltage sensing type sensing circuit 20 of FIG. 5 senses the voltage stored in the line capacitor LCa of the sensing line 14B in response to the pixel current flowing through the driving TFT DT. The voltage sensing type sensing circuit 20 may include an initialization switch (SW1), a sampling switch (SW2), a sample and hold unit (S/H), and an analog-to-digital converter (ADC). The initialization switch (SW1) turns on/off the electrical connection between the input terminal of the reference voltage (Vref) and the sensing line (14B) according to the initialization control signal (PRE). The sampling switch (SW2) turns on/off the electrical connection between the sensing line (14B) and the sample and hold unit (S/H) according to the sampling control signal (SAM). When the source node (Ns) voltage of the driving TFT (DT) changes according to the pixel current of the driving TFT (DT), the sample and hold unit (S/H) detects the sensing line at a specific point in time when the sampling switch (SW2) is turned on. The source node (Ns) voltage of the driving TFT (DT) stored in the line capacitor (LCa) of (14B) is sampled and held as an analog sensing value and then transmitted to the analog-to-digital converter (ADC). The analog-to-digital converter (ADC) converts the analog sensing value input from the sample and hold unit (S/H) into a digital sensing value (SDATA).

The current sensing circuit 20 of FIG. 6 directly senses the pixel current (Ipixel) of the driving TFT transmitted through the sensing line 14B, and includes a current integrator (CI), a sample & hold unit (SH), and an analog -May include a digital converter (ADC). The current integrator (CI) generates an analog sensing value (Vsen) by integrating the pixel current (Ipixel) flowing in through the sensing line (14B). The current integrator (CI) has an inverting input terminal (-) that receives the pixel current (Ipixel) of the driving TFT from the sensing line (14B), a non-inverting input terminal (+) that receives the reference voltage (Vpre), and an output terminal. It includes an amplifier (AMP), an integral capacitor (Cfb) connected between the inverting input terminal (-) and the output terminal of the amplifier (AMP), and a reset switch (RST) connected to both ends of the integral capacitor (Cfb). . The current integrator (CI) is connected to the analog-to-digital converter (ADC) through the sample & hold section (SH). The sample & hold unit (SH) is a sampling switch (SAM) that samples the analog sensing value (Vsen) output from the current integrator (CI) and stores it in the sampling capacitor (Cs), and the sensing value (Vsen) stored in the sampling capacitor (Cs). ) may include a holding switch (HOLD) for transferring the signal to an analog-to-digital converter (ADC). The analog-to-digital converter (ADC) converts the analog sensing value (Vsen) input from the sample and hold unit (S/H) into a digital sensing value (SDATA).

Figures 7 and 8 are diagrams showing a full sensing method targeting all pixel lines regardless of data patterns as a comparative example of the present invention.

Referring to Figures 7 and 8, in the comparative example of the present invention, all pixel lines of the display panel 10 are sensed randomly or sequentially and then compensated. In the comparative example of the present invention, compensation is performed after sensing all pixel lines, so the sensing and compensation cycle is predetermined. For example, if the sensing & compensation cycle for single color pixels is 36 seconds based on UHD resolution, the sensing & compensation cycle for all pixels may be 144 seconds. Here, the monochromatic color pixels may be any one of red pixels (PR), green pixels (PG), blue pixels (PB), and white pixels (PW). All pixels include red pixels (PR), green pixels (PG), blue pixels (PB), and white pixels (PW). In the comparative example of the present invention, since all pixel lines of the display panel 10 are fully sensed in each of the n-1th sensing cycle, the nth sensing cycle, and the n+1th sensing cycle, the sensing & compensation cycle is always the same at 144 seconds. do.

In certain image patterns that cause temperature increases or short-term afterimages, the driving characteristics of pixels may change faster than the predetermined compensation period, deteriorating real-time compensation performance. However, in the case of full sensing of all pixel lines as in the comparative example of the present invention, the sensing time and compensation cycle for pixels are long, and luminance uniformity may be deteriorated in some areas where a specific image pattern is displayed.

Figures 9 and 10 are diagrams showing, as an embodiment of the present invention, a full sensing method for all pixel lines and a partial sensing method for some pixel lines are used in parallel according to a data pattern. And, Figure 11 is a diagram showing an example of a fixed pattern.

9 and 10, the organic light emitting display device according to an embodiment of the present invention divides the display areas of the display panel 10 into a specific display area and a normal display area based on the analysis result of the input image data (IDATA). Separate into The specific display area is an area where a specific data pattern that causes the driving characteristics of the pixels P to change relatively quickly is displayed, and area 2 in FIG. 9 corresponds to this area. The normal display area is an area where normal data patterns other than specific data patterns are displayed, and areas 1 and 3 in FIG. 9 correspond to this area. The normal data pattern causes the driving characteristics of the pixels (P) to change relatively slowly compared to the specific data pattern.

A specific data pattern may be a fixed pattern without video movement. The fixed pattern may be various still image patterns, including a logo on a TV screen as shown in FIG. 11, a Windows start bar on a laptop or monitor, etc.

The organic light emitting display device according to an embodiment of the present invention uses the first sensing & compensation cycle for the driving characteristics of pixels arranged in a specific display area (area 2 in FIG. 9) to the normal display area (area 1 and area 3 in FIG. 9). ) can be made shorter than the second sensing & compensation period for the driving characteristics of the pixels arranged in ). For example, the embodiment of the present invention partially senses only the driving characteristics of pixels arranged in a specific display area (area 2 in FIG. 9) in each of the n-1th sensing cycle and the nth sensing cycle, and In the sensing cycle, the driving characteristics of the pixels arranged in all pixel lines including the normal display area (area 1 and area 3 in FIG. 9) and the specific display area (area 2 in FIG. 9) of the display panel 10 are full. ) Sensing. Based on UHD resolution, if the number of pixel lines included in areas 1, 2, and 3 is the same, the n-1th sensing cycle and the nth sensing cycle are each 48 seconds, and the n+1th sensing cycle is 144 seconds.

In this way, the organic light emitting display device according to an embodiment of the present invention senses and compensates for the driving characteristics of pixels arranged in the normal display area (area 1 and area 3 in FIG. 9) once, while the driving characteristics of the pixels arranged in the normal display area (area 1 and area 3 in FIG. 9) are sensed and compensated once. By controlling the driving characteristics of the pixels arranged in area 2) to be sensed and compensated three times, the compensation cycle of the area where the fixed pattern is displayed can be speeded up.

Meanwhile, the fixed pattern may include a single color pattern composed of single colors and a worst color pattern composed of a combination of at least two or more single colors. Compared to a single color pattern, the change in driving characteristics of pixels is relatively large in the worst color pattern due to the influence of temperature.

A single color pattern and a worst color pattern can be distinguished by the number of lit pixels within a unit pixel. A single color pattern has a single number of pixels lit in a unit pixel, and a worst color pattern has a plurality of pixels lit in a unit pixel. In the case of a WRGB panel, which consists of a unit pixel of white, red, green, and blue pixels, the worst color pattern is a Magenta pattern made of a combination of red and blue, a Yellow pattern made of a combination of red and green, and It may be a cyan pattern made up of a combination of green and blue. Meanwhile, in the case of an RGB panel that constitutes a unit pixel with red, green, and blue pixels, the worst color pattern is the Magenta pattern, the Yellow pattern, the Cyan pattern, and red, green, and blue. It may be a white pattern composed of a combination of .

Even within a specific display area where a fixed pattern is displayed, the driving characteristics of pixels change relatively faster in the area with the worst color pattern. Therefore, the timing controller 11 of the present invention controls the first sensing & compensation cycle of pixels displaying a worst color pattern in a specific display area to be shorter than the first sensing & compensation cycle of pixels displaying a single color pattern. , Effectively compensates for luminance deviations due to differences in deterioration rates within a specific display area.

Meanwhile, the timing controller 11 can store and know in advance the location of a specific display area where a fixed pattern is displayed even without referring to the analysis result of the input image data. This designated area may be the broadcaster logo area at the top of the TV screen or the bottom bar area of the window of a laptop or monitor. The timing controller 11 may preferentially apply the first sensing & compensation cycle to this designated area.

FIG. 12 corresponds to FIGS. 7 and 8 and shows that the sensing and compensation cycles are the same in areas displaying specific data patterns and normal data patterns. And, Figure 13 corresponds to Figures 9 and 10 and shows that the sensing & compensation cycles are different in areas displaying specific data patterns and normal data patterns.

Referring to FIG. 12, in the case of the comparative example of the present invention, the sensing & compensation cycle is fixed to 2160 frames in areas displaying specific data patterns and normal data patterns.

On the other hand, in the case of the embodiment of the present invention shown in FIG. 13, the sensing & compensation period is changed to 720 frames and 4320 frames in areas displaying specific data patterns and normal data patterns, respectively.

Through the above-described content, those skilled in the art will be able to see that various changes and modifications can be made without departing from the technical idea of the present invention. Therefore, the technical scope of the present invention should not be limited to what is described in the detailed description of the specification, but should be defined by the scope of the patent claims.

10: display panel 11: timing controller
12: data driving circuit 13: gate driving circuit
14A: data line 14B: sensing line
15: gate line 20: sensing circuit

Claims (13)

A display panel with a plurality of pixels arranged in each display area; and
The display areas are divided into a specific display area in which a specific data pattern is displayed and a normal display area in which a normal data pattern other than the specific data pattern is displayed, and a first sensing <RTI ID=0.0>driving characteristic of pixels arranged in the specific display area</RTI> A timing controller that differently controls a compensation period and a second sensing & compensation period for driving characteristics of pixels arranged in the normal display area,
The specific data pattern includes a fixed pattern without video movement,
The fixed pattern includes a single color pattern composed of single colors, and a worst color pattern composed of a combination of at least two or more single colors,
The timing controller is,
An organic light emitting display device that controls the first sensing & compensation cycle of pixels displaying the worst color pattern in the specific display area to be shorter than the first sensing & compensation cycle of pixels displaying the single color pattern. delete delete According to claim 1,
The timing controller is,
An organic light emitting display device that controls the first sensing & compensation period to be shorter than the second sensing & compensation period. delete In the pixel compensation method of an organic light emitting display device having a display panel in which a plurality of pixels are arranged in each of a plurality of display areas,
dividing the display areas into a specific display area where a specific data pattern is displayed and a normal display area where a normal data pattern other than the specific data pattern is displayed; and
Comprising a step of controlling a first sensing & compensation cycle for driving characteristics of pixels arranged in the specific display area and a second sensing & compensation cycle for driving characteristics of pixels arranged in the normal display area to be different from each other,
The specific data pattern includes a fixed pattern without video movement,
The fixed pattern includes a single color pattern composed of single colors, and a worst color pattern composed of a combination of at least two or more single colors,
Organic light emitting display further comprising controlling a first sensing & compensation cycle of pixels displaying the worst color pattern in the specific display area to be shorter than a first sensing & compensation cycle of pixels displaying the single color pattern. How your device compensates for pixels. delete delete According to claim 6,
The step of controlling the first sensing & compensation cycle and the second sensing & compensation cycle differently from each other,
A pixel compensation method for an organic light emitting display device, which includes controlling the first sensing & compensation period to be shorter than the second sensing & compensation period. delete According to claim 1,
The single color pattern has a single number of pixels lit in a unit pixel, and the worst color pattern has a plurality of pixels lit in the unit pixel. According to claim 11,
When the unit pixel is composed of white, red, green, and blue pixels, the worst color pattern includes a magenta pattern composed of a combination of the red and the blue, a yellow pattern composed of a combination of the red and the green, and the green and the Contains a cyan pattern composed of a combination of blue,
When the unit pixel is composed of red, green, and blue pixels, the worst color pattern includes the magenta pattern, the yellow pattern, the cyan pattern, and a white pattern composed of a combination of the red, green, and blue colors. Luminous display device. According to claim 1,
The timing controller partially senses only the driving characteristics of pixels arranged in the specific display area in each of the n-1th sensing cycle (n is a natural number of 2 or more) and the nth sensing cycle, and displays the display panel ( An organic light emitting display device that fully senses the driving characteristics of pixels arranged in all pixel lines, including the normal display area of 10) and the specific display area.