KR20150078357A - Orgainc emitting diode display device and compensating method thereof - Google Patents

Abstract

The present invention relates to an organic light-emitting diode (OLED) display device and a compensation method thereof, wherein the device is capable of reducing boot time by decreasing initial compensation information loading time and initial sensing time. An initial compensation method of the present invention comprises: a first step of loading a color gain, which represents a characteristic correlation between a reference sub-pixel and each of the remaining sub-pixels of each pixel, and reference compensation information to compensate for the characteristics of the reference sub-pixel in a non-volatile memory; a second step of detecting sensing compensation information by sensing the characteristics of the reference sub-pixel of each pixel and detecting reference condition compensation information of the reference sub-pixel using the reference compensation information and the sensing compensation information; a third step of detecting condition compensation information for each of the remaining sub-pixels of each pixel using the reference condition compensation information and the color gain; and a fourth step of detecting compensation information to compensate for the characteristics of each sub-pixel using the reference compensation information and the condition compensation information of each sub-pixel and storing the compensation information in the non-volatile memory.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display device and a method of compensating the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting diode (OLED) display device, and more particularly, to an OLED display device and its compensation method capable of reducing boot time by reducing initial compensation information loading time and initial sensing time will be.

2. Description of the Related Art Recently, flat panel display devices that display images using digital data include liquid crystal displays (LCDs) using liquid crystals, OLED display devices using OLEDs, electrophoretic displays (EPDs) using electrophoretic particles ).

Of these, OLED display devices are self-luminous devices that emit organic light-emitting layers by recombination of electrons and holes, and are expected to be a next-generation display device because of their high luminance, low driving voltage, and ultra thin films.

Each of the plurality of pixels (subpixels) constituting the OLED display device includes an OLED element composed of an organic light emitting layer between the anode and the cathode, and a pixel circuit independently driving the OLED element. The pixel circuit includes at least a switching transistor and a storage capacitor and a driving transistor. The switching transistor charges the storage capacitor with a voltage corresponding to the data signal in response to the scan pulse, and the driving transistor controls the current supplied to the OLED element according to the voltage charged in the storage capacitor to adjust the amount of light emitted from the OLED element. The amount of light emission of the OLED is proportional to the current supplied from the driving transistor.

The OLED display has a problem of luminance non-uniformity among sub-pixels due to various reasons. For example, there are differences in driving characteristics for each subpixel such as a threshold voltage (hereinafter referred to as Vth) and mobility of a driving TFT due to a process variation or the like, and deterioration of the driving TFT and the OLED element Etc., the pixel driving characteristics are variable and the pixel current varies, resulting in a problem of luminance unevenness with respect to the same data.

In order to solve such a problem, the OLED display device uses an external data compensation method of sensing characteristic information of each sub-pixel and compensating the video data using the sensing information.

For external data compensation, the OLED display needs a loading process to load initial compensation information stored in a NAND flash memory, which is a nonvolatile memory, into a DDR (Double Data Rate) memory, which is a volatile memory, when the power is turned on .

Since the mobility of the oxide TFT varies depending on the temperature change to affect the image quality, the OLED display senses the mobility characteristic information of the driving TFT in each sub-pixel when the power is turned on, An initial temperature compensation process is required to compensate for the temperature.

It is preferable that the loading process and the initial temperature compensation process are performed within a boot time of 2 seconds or less before the power is turned on and the image is displayed on the display panel in order to prevent the user from being perceived.

However, as the resolution increases, such as UHD (Ultra High Definition), the initial compensation information size for each subpixel increases and the time for loading the initial compensation information increases. In addition, the number of subpixel lines increases, There is a problem that the boot time increases due to an increase in the sensing time or the normal screen is not displayed within a predetermined boot time, thereby causing inconvenience to the user.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an OLED display device and a compensation method thereof that can reduce a boot time by reducing an initial compensation information loading time and an initial sensing time .

According to an aspect of the present invention, there is provided a method of compensating for an OLED display device, the OLED display device including a plurality of sub-pixels each having a different color, Wherein the reference compensation information for compensating the characteristic of the reference subpixel is stored in a nonvolatile memory in a nonvolatile memory, A first step of loading; A second step of detecting sensing compensation information by sensing a characteristic of the reference subpixel among the pixels and detecting reference condition compensation information of the reference subpixel using the reference compensation information and the sensing compensation information; A third step of detecting condition compensation information for each of the remaining subpixels using the reference condition compensation information and the color gain; And a fourth step of detecting compensation information for compensating the characteristics of each subpixel using the reference compensation information and the condition compensation information of each subpixel, and storing the compensation information in a volatile memory.

An OLED display according to an embodiment of the present invention includes: a display panel including a plurality of subpixels each of which constitutes a pixel array, the plurality of subpixels having different colors; A data driver driving a data line of the display panel and sensing a signal including characteristics of each sub pixel through a sensing line of the display panel to output sensing data; A gate driver for driving a gate line of the display panel; And a timing controller for controlling driving of the data driver and the gate driver; The timing controller includes a color gain for indicating a characteristic correlation between one reference subpixel of each pixel and each of the remaining subpixels for initial compensation performed at a boot time and a reference value for compensating a characteristic of the reference subpixel Loading compensation information from the non-volatile memory into the volatile memory; Detecting sensing compensation information by sensing characteristics of the reference subpixel among the pixels through the data driver, detecting reference condition compensation information of the reference subpixel using the reference compensation information and the sensing compensation information; Detecting condition compensation information for each of the remaining subpixels using the reference condition compensation information and the color gain; The compensation information for compensating the characteristics of each subpixel is detected using the reference compensation information and the condition compensation information of each subpixel, and the compensation information is stored in the volatile memory.

The color gain is determined by a ratio between representative condition compensation information of the reference subpixel obtained through modeling and representative condition compensation information of each of the remaining subpixels, and is set in advance before shipment of the product together with the reference compensation information, And stored in the memory.

The exemplary condition compensation information may be condition compensation information for each subpixel or an average value of color compensation information for each color block unit, horizontal line unit, or frame unit including a plurality of subpixels; Wherein the condition compensation information of each subpixel includes initial compensation information for compensating initial mobility characteristics of each subpixel and sensing compensation information for compensating mobility characteristics of each subpixel sensed through the modeling Is determined by the difference.

The reference sub-pixel may be any one of R / G / B sub-pixels or R / G / B / W sub-pixels in each pixel.

Wherein the timing controller detects the reference condition compensation information of the reference subpixel by a difference between the reference compensation information of the reference subpixel and the sensing compensation information detected through sensing of the reference subpixel; Detecting condition compensation information of each of the remaining subpixels by multiplying the reference condition compensation information by the color gain; Detecting compensation information for each subpixel by summing the reference compensation information and the condition compensation information detected for each subpixel; The reference compensation information, the reference condition compensation information, the condition compensation information, and the compensation information are compensation values for compensating the mobility characteristics of the corresponding subpixel.

The timing controller is configured to perform the loading of the reference compensation information and the color gain, the detection of the reference condition compensation information of the reference subpixel, the detection of the condition compensation information of the remaining subpixels, , And repeats the above operation up to the last horizontal line.

The OLED display according to the present invention and the method of compensating the OLED display according to the present invention are characterized by loading reference compensation information for one color reference pixel of each pixel in the loading step, Can be reduced.

In addition, since the OLED display according to the present invention and its compensation method only need to sense the characteristics of the reference sub-pixels among the pixels in the initial compensation step, the initial sensing time can be reduced compared to the case of sensing all the sub-pixels.

As a result, the OLED display and its compensation method according to the present invention reduce the loading time and the initial sensing time of the initial compensation information, thereby reducing the boot time, securing the additional sensing time to improve the compensation performance, It is possible to display the normal screen to the user by completing the initial compensation within the promised boot time.

FIG. 1 and FIG. 2 are views showing a comparison of a sensing frame for initial compensation of the OLED display according to the present invention and the prior art of the present invention.
FIG. 3 is a view showing a distribution of first compensation information of the OLED display device for each color frame in order to facilitate understanding of the present invention.
FIG. 4 is a diagram showing a normal distribution diagram of second compensation information of an OLED display device for each color frame in order to facilitate understanding of the present invention.
FIG. 5 is a diagram illustrating color temperature compensation information and color-by-color temperature compensation information sensed on a horizontal line according to a temperature change in the OLED display device according to the present invention.
6 is a block diagram illustrating an OLED display device according to an embodiment of the present invention.
7 is a flow chart for explaining an initial compensation method of an OLED display according to an embodiment of the present invention.

FIG. 1 and FIG. 2 are views for comparing a sensing frame, that is, a sensing time, for initial compensation of the OLED display according to the present invention and the prior art of the present invention.

The OLED display device has a problem that the temperature of the display device varies due to the ambient temperature such as a high temperature region or a low temperature region and the temperature of an object (a user's palm, a board, a stove, etc.) , In particular, the mobility characteristics of the oxide TFT are changed to affect the image quality. In order to compensate for the mobility characteristics due to external environmental conditions such as temperature and illumination, the OLED display is operated in the initial booting stage, which is not recognized by the user when the power is turned on, The initial environment compensation for sensing the mobility characteristic of the pixel and correcting the preset initial compensation information is performed.

The initial compensation information includes first initial compensation information for compensating a mobility characteristic of a driving TFT of each subpixel and second initial compensation information for compensating a threshold voltage (Vth) characteristic of a driving TFT of each subpixel , The first initial compensation information is corrected by the initial compensation.

For the initial environment compensation, in the prior art of the present invention, one frame is divided into R / W / G / B subframes as shown in FIG. 1, and sub- And corrects the first initial compensation information for each of the pixels.

Specifically, a pixel array of the OLED display is configured by sensing R sub-pixels in the R sub-frame, W sub-pixels in the W sub-frame, G sub-pixels in the G sub-frame, and B sub- The R / W / G / B sub-pixels are all sensed to correct the first initial compensation information for each sub-pixel.

The first initial compensation information for each subpixel is preset for each of the R / W / G / B subpixels of the pixel array to compensate for the initial characteristics of each subpixel before shipment of the product. Which is a volatile memory, from a NAND flash memory that is a nonvolatile memory. Of course, the second initial compensation information for each subpixel is also loaded at the booting stage, but this is the same as the prior art and the present invention, so a description thereof will be omitted

The OLED display according to the prior art must load the first initial compensation information set in advance for each R / W / G / B subpixel in the booting step and the subpixels in each R / W / G / Therefore, as the resolution increases, the loading time and sensing time increase.

In order to solve the problems of the prior art, the OLED display according to the present invention is characterized in that, in the initial compensation step, only the reference subpixels corresponding to one color among the plurality of colors of each pixel, And the condition compensation information DELTA alpha for each of the remaining color subpixels in each pixel is calculated based on the correlation between the reference subpixel and the corresponding subpixel The color gain g representing the reference color and the reference condition compensation information DELTA alpha.

Here, the reference condition compensation information? Is detected as the difference between the first sensing compensation information obtained by sensing the mobility characteristic of the reference subpixel in the current external environment and the first initial compensation information set in advance. The color gain g is previously set by using the ratio of the condition compensation information of the reference subpixel and the corresponding subpixel through modeling.

Accordingly, since only one reference sub-frame needs to be sensed at boot time, the sensing time can be reduced to 1/4 of that of prior art sensing each R / W / G / B sub-frame. In addition, since the first initial compensation information is stored in advance in the NAND flash memory and loaded in the DDR memory only for the reference subpixels corresponding to one color of the plurality of colors, the R / W / G / B subpixels It is possible to shorten the loading time compared to the prior art in which the first initial compensation information is loaded.

The reference subpixel may be determined to be one of R / W / G / B subpixels or R / G / B subpixels, Only the case where the pixel is used as a pixel will be described as an example.

For example, when the R subpixel is set as the reference subpixel, only the R subpixels are sensed for initial compensation to detect the reference condition compensation information?? R corresponding to the current external environmental condition, The condition compensation information ?? _W, ?? _G, ?? _B for each of the pixels is detected using the color gain g_W, g_G, g_B indicating the correlation between the reference subpixel and the other subpixel and the reference condition compensation information ?? do.

The color gains g_W, g_G and g_B are representative condition compensation information for compensating the mobility characteristics of the reference subpixel through modeling using test images in a plurality of environmental conditions at the initial sensing stage before shipment or after shipment of the product Δα_R) and representative condition compensation information Δα_W, Δα_G, Δα_B for compensating the mobility characteristic of each of the remaining subpixels, that is, a proportional relation.

The color gain (g_W, g_G, g_B) is set so that the mobility characteristics of the R / W / G / B subpixels are similar or proportional to each other, And the color-dependent compensation information? For each of the R / W / G / B subframes has a similar distribution to each other as shown in FIG. 3 and FIG. Further, as shown in Fig. 5, the amount of change according to the temperature of the color-by-color compensation information?, That is, the condition compensation information? Is also proportional to each color.

FIG. 3 is an image distribution of alpha distribution for each color in each R / W / G / B subframe, and FIG. 4 is a diagram showing the distribution of alpha for each color in a normal distribution diagram.

In Fig. 3, a value of a is expressed darkly, and a value of a is brightly expressed.

Referring to FIGS. 3 and 4, the? Distribution of R subframes for compensating the mobility characteristics of R subpixels, the? Distribution of W subframes for compensating the mobility characteristics of W subpixels, The distribution of the G subframe for compensating the mobility characteristic of the B subframe, the distribution of the B subframe for compensating the mobility characteristics of the B subpixels, and the distribution pattern of the normal distribution by color are similar to each other , The average value of the alpha distribution by color can be known.

FIG. 5 is a graph showing the relationship between the actual condition compensation information (?) Detected from the sensing information of the Nth horizontal line and the color gain from the condition compensation information of the reference subpixel And the predicted condition compensation information?

Referring to FIG. 5, when the temperature distribution of the panel is different by hot plates having different temperatures as shown in (a), sensing compensation information sensed from the R / W / G / B subpixels of the Nth horizontal line Actual condition compensation information (Δα_R, Δα_W, Δα_G, Δα_B), which is a difference from the initial compensation information, is different for each color as shown in (b), but has a similar distribution profile in which the condition compensation information , Actual condition compensation information for each color (?? _R,?? W,?? _G,?? _B) are proportional to each other.

(M_R, m_W, m_G, m_B) of the color-by-color actual condition compensation information (Δα_R, Δα_W, Δα_G, Δα_B) in the Nth horizontal line as representative values. G / B subpixel based on the R subpixel by calculating the ratio of each of the average values m_W, m_G and m_B of the W / G / B subpixels on the basis of the average value m_R of the R subpixels, The color gain g_W, g_G, g_B for each of the B subpixels can be detected.

g_W = m_W / m_R

g_G = m_G / m_R

g_B = m_B / m_R

For example, in FIG. 5B, the reference gain of the R subpixel is 1, the color gain g_W of the W subpixel is 0.8, the color gain g_G of the G subpixel is 0.6, the color gain of the B subpixel And the gain g_B is 1.2.

The color gain g_W, g_G, g_B detected by using FIG. 5 (b) is calculated with the actual condition compensation information? __R of the R subpixels to obtain the condition compensation information?? _W,?? _G , Δα_B) is predicted in FIG. 5 (c), and it can be seen that the prediction information in FIG. 5 (c) has an approximate value of the actual information in FIG. 5 (b).

Accordingly, the OLED display according to the present invention senses only the reference subpixels in the initial compensation step to detect the reference condition compensation information according to the current external environmental condition, and the condition compensation information for each of the remaining color subpixels is the reference subpixel And the color gain and the reference condition compensation information which are correlations with the corresponding subpixel, the loading time and the sensing time of the initial compensation information can be reduced.

6 is a block diagram schematically showing an OLED display device according to an embodiment of the present invention.

The OLED display device shown in FIG. 6 includes a timing controller 10, a data driver 20, a gate driver 30, a gamma voltage generator 40, a display panel 50, a NAND flash memory 60, and a DDR memory 70).

In the NAND flash memory 60, which is a non-volatile memory, initial compensation information and color gain including first reference compensation information and second initial compensation information together with various control information to be used in the timing controller 10 are preset and stored . Various information stored in the NAND flash memory 60 is loaded into the DDR memory 70 which is a volatile memory at boot time when the power of the OLED display device is turned on and used by the timing controller 10.

The initial compensation information is preset before shipment of the product, and the first initial compensation information for compensating the mobility characteristic of the reference sub-pixel among R / G / B or R / W / G / B sub- Information, and does not include the first initial compensation information for the subpixels of the remaining colors. Also, the initial compensation information includes second initial compensation information for compensating the threshold voltage characteristic of each subpixel.

The color gain representing the correlation between the reference subpixel and each of the remaining color subpixels is determined through pre-shipment modeling.

In the modeling, first initial compensation information for sensing and compensating the initial mobility characteristics of each sub-pixel is detected for each R / W / G / B sub-pixel, and the mobility characteristic of each sub- W / G / B subpixels for detecting the first sensing compensation information for sensing and compensating the first sensing compensation information, and then transmits the condition compensation information corresponding to the difference between the first initial compensation information and the first sensing compensation information to the R / W / G / B < / RTI > Next, the average value of the condition compensation information is detected as a representative value for each color in block unit, horizontal line unit, or frame unit including a plurality of sub-pixels, and a ratio of each W / G / B average value is calculated based on the R average value And the color gain of each of W / G / B is determined. On the other hand, the color gain of each W / G / B can be determined as the ratio of the condition compensation information of the R subpixel to the condition compensation information of each of the W / G / B subpixels without calculating the average value.

The first reference compensation information and the color gain loaded from the NAND flash memory 60 into the DDR memory 70 are used for detecting and storing the first compensation information of each subpixel by the initial compensation, The compensation information is used to compensate the mobility characteristics of each subpixel, and the first compensation information can be updated and used through real-time compensation. The second initial compensation information is used to compensate the threshold voltage characteristic of each subpixel and updated with the second compensation information through real-time compensation.

The timing controller 10 generates a data control signal and a gate control signal for controlling the driving timings of the data driver 20 and the gate driver 30 using a plurality of synchronous signals inputted from the outside, And the gate driver 30.

The timing controller 10 modulates an input image through various data modulation methods for improving image quality and power consumption, and outputs the modulated data to the data driver 20. [

The timing controller 10 senses the mobility characteristic of the reference sub-pixel among the pixels using the reference compensation information stored in the DDR memory 70 in the initial temperature compensation process, and generates sensing compensation information for compensating the sensed mobility characteristic And detects the difference between the sensing compensation information and the reference compensation information as the reference condition compensation information. The timing controller 10 detects the condition compensation information of each of the remaining subpixels excluding the reference subpixel among the pixels using the reference condition compensation information and the color gain, And stores the correction result in the DDR memory 70 as first compensation information of each subpixel.

The timing controller 10 compensates the video data of each subpixel using the first and second compensation information of each subpixel stored in the DDR memory 70. [ For example, the timing controller 10 compensates the video data by multiplying the video data by the second compensation information and adding the first compensation information.

The timing controller 10 senses the characteristics of each subpixel through the data driver 20 and updates the first and second compensation information for compensating the mobility characteristics and the threshold voltage characteristics.

The timing controller 10 determines the peak luminance according to the image characteristic information such as the average picture level (APL) detected from the input image, adjusts the gamma high potential power according to the determined peak luminance, And supplies the power source to the gamma voltage generating unit 40.

The gamma voltage generator 40 generates and supplies a gamma voltage set including a plurality of gamma voltages having different levels to the data driver 20. The gamma voltage generator 40 divides the high gamma voltage by a resistor string to generate and output a gamma voltage set including a plurality of gamma voltages. The gamma voltage generator 40 may be embedded in the data driver 20.

The data driver 20 converts the digital data from the timing controller 10 into an analog data signal in response to a data control signal from the timing controller 10 and supplies it to a plurality of data lines of the display panel 50. At this time, the data driver 20 subdivides the gamma voltage set from the gamma voltage generator 40 into gradation voltages corresponding to the gradation values of the data, and then uses the subdivided gradation voltages to convert the digital data into analog data signals . The data driver 20 is driven under the control of the timing controller 10 in a sensing mode for external compensation and a display mode for display driving.

The data driver 20 includes at least one data drive IC and is mounted on a circuit film such as a tape carrier package (TCP), a chip on film (COF), or a flexible printed circuit (FPC) (Tape Automatic Bonding) method, or on a non-display area of the display panel 50 by a COG (Chip On Glass) method.

The gate driver 30 sequentially drives a plurality of gate lines of the display panel 50 in response to a gate control signal from the timing controller 10. [ The gate driver 30 supplies a gate-on voltage to the respective gate lines in response to the gate control signal, and supplies a gate-off voltage in the remaining periods. The gate driver 30 may receive a gate control signal directly from the timing controller 10 or may receive a gate control signal from the timing controller 10 via the data driver 20. [

The gate driver 30 is composed of at least one gate drive IC and is mounted on a circuit film such as TCP, COF, FPC or the like to be attached to the display panel 50 in a TAB manner, Area. ≪ / RTI > Alternatively, the gate driver 30 may be formed in a non-display area of the TFT substrate together with the TFT array formed in the pixel array of the display panel 50, thereby forming a gate in panel (GIP) type built in the display panel 50 .

The display panel 50 includes a pixel array in the form of a matrix. Each pixel of the pixel array implements a desired color with a combination of red (R), green (G), and blue (B) subpixels, and further has white (W) subpixels for luminance enhancement.

Each sub-pixel has an OLED element and a pixel circuit for driving the OLED element. The pixel circuit includes first and second switching TFTs ST1 and ST2, a driving TFT DT and a storage capacitor Cst. The pixel circuit further includes first and second gate lines GLn1 and GLn2 for controlling the first and second switching TFTs ST1 and ST2 respectively and a data line for supplying a data signal to the first switching TFT ST1 A reference line RLm for supplying a reference voltage Vref to the second switching TFT ST2, an ELVDD line for supplying a high potential power supply ELVDD to the driving TFT DT, And is connected to an ELVSS line that supplies a low potential power supply (ELVSS).

The OLED is connected in series with the driving TFT (DT) between the ELVDD line and the ELVSS line. The OLED has an anode connected to the driving TFT (DT), a cathode connected to the ELVSS line, and a light emitting layer between the anode and the cathode. The light emitting layer includes an electron injection layer, an electron transport layer, an organic light emitting layer, a hole transport layer, and a hole injection layer sequentially stacked between the cathode and the anode. In the OLED, when a positive bias is applied between the anode and the cathode, electrons from the cathode are supplied to the organic light emitting layer via the electron injection layer and the electron transport layer, and holes from the anode are supplied to the organic light emitting layer via the hole injection layer and the hole transport layer do. Accordingly, in the organic light emitting layer, light is generated which is proportional to the amount of current by causing the fluorescent or phosphorescent material to emit by recombination of the supplied electrons and holes.

The first switching TFT ST1 charges the storage capacitor Cst with a voltage corresponding to the data signal from the data line DL in response to the control of the first gate line GLn1. At this time, the second switching TFT ST2 supplies the reference voltage Vref from the reference line RLm to the connection node between the driving TFT DT and the OLED element in response to the control of the second gate line GLn2 . The driving TFT DT controls the current supplied to the OLED element according to the voltage charged in the storage capacitor Cst to adjust the amount of light emitted from the OLED element. On the other hand, the second switching TFT ST2 can be used as a path for supplying the pixel current output to the reference line RLm according to the driving characteristic of the pixel circuit in the sensing mode.

In response to the control of the timing controller 10 in the sensing mode, the data driver 20 supplies the test data (precharge data) to the data lines to drive the subpixels, (Voltage or current) included therein, converts the sensing signal into digital sensing data, and transmits the digital sensing data to the timing controller 10. The sensing channel may be a reference line for supplying a reference voltage for driving each sub-pixel, a data line for supplying test data, or a lead-out line provided separately from the reference line.

The timing controller 10 senses the characteristic information of each subpixel using the sensing data transmitted from the data driver 20 and detects first and second compensation information for compensating the characteristic information of the sensed subpixel And stores it in the DDR memory 70.

For example, the timing controller 10 calculates a pixel current by using the sensing data of each sub-pixel transmitted from the data driver 20, and calculates a pixel current according to the Vth and K factor of the driving TFT And the Vth component and K factor component of each sub-pixel are sensed. The timing controller 10 updates the second compensation information by storing an offset value for compensating the Vth of each subpixel as second compensation information in the DDR memory 70 and compensates the K factor of each subpixel And stores it as the first compensation information in the DDR memory 70 to update the first compensation information.

The timing controller 10 drives the display panel 50 in a sensing mode before shipment of the display device, boot-up time at power-on, end time at power-off, or blank period of each frame, To generate or update compensation information whenever necessary.

7 is a flow chart showing a step of an initial temperature compensation method of an OLED display according to an embodiment of the present invention.

The reference subpixel may be determined to be one of R / W / G / B subpixels or R / G / B subpixels, Only the case where the pixel is used as a pixel will be described as an example.

When the power of the OLED display device is turned on in step 2 (S2), in step S4 (S4), the timing controller 10 counts the initial compensation information, reference compensation information, and color gain for one horizontal line stored in the NAND flash memory 60 And loads it into the DDR memory 70.

The reference compensation information is first initial compensation information for compensating the mobility characteristic of each of the R subpixels, which is a reference subpixel among R / W / G / B subpixels, and the initial compensation information is R / W / G / B And second initial compensation information for compensating the threshold voltage characteristic of each of the subpixels. The color gain represents the proportional relationship between the condition compensation information of the reference R subpixel and the condition compensation information of each of the remaining W / G / B subpixels.

In step 6 (S6), the timing controller 10 senses the R sub-pixels of one horizontal line through the data driver 20, and detects the first sensing compensation information for compensating the mobility characteristic.

In step 8 (S8), the timing controller 10 compares the first sensing compensation information with the first initial compensation information, and detects the reference condition compensation information?? R corresponding to the difference value.

In step S10 (S10), the timing controller 10 multiplies the W / G / B color gains g_W, g_G and g_B respectively by the reference condition compensation information Δα_R and the W / G / And detects the condition compensation information?? _W,?? _G,?? _B.

In step 12 (S12), the timing controller 10 adds each of the condition compensation information (?? R,?? W,?? G and?? B) of the R / W / G / B subpixels to the reference compensation information? The first compensation information (? '- R,?' - W,? '- G, and?' - B) of each of the R / W / G / B subpixels whose mobility characteristics are calculated according to the mobility characteristics is calculated and stored in the DDR memory.

In step 14 (S14), the timing controller 10 repeats the above step 4 (S4) to step 14 (S14) on a horizontal line basis until the current horizontal line becomes the last line.

If the current horizontal line is the last horizontal line in step 14 (S14), the timing controller 10 turns on the display in step 16 (S16) so that the normal screen is displayed on the display panel 50.

As described above, in the OLED display according to the present invention and its initial compensation method, when the initial compensation information for each of all the subpixels is loaded by loading the reference compensation information for one reference color subpixel of each pixel in the loading step The initial loading time can be reduced.

In addition, since the OLED display according to the present invention and its initial compensation method only need to sense the characteristics of the reference sub-pixels among the pixels in the initial compensation step, the initial sensing time can be reduced compared to the case of sensing all the sub-pixels.

As a result, the OLED display device and its initial compensation method according to the present invention reduce the booting time by reducing the loading time and the initial sensing time of the initial compensation information, improve the compensation performance by securing additional sensing time, It is possible to display the normal screen to the user by completing the initial compensation within the promised boot time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, Can be carried out within a range. Accordingly, such modifications are deemed to be within the scope of the present invention, and the scope of the present invention should be determined by the following claims.

10: timing controller 20: data driver
30: gate driver 40: gamma voltage generator
50: Display panel 60: NAND flash memory
70: DDR memory

Claims (12)

An initial compensation method implemented at boot time in an OLED display device wherein each pixel of the pixel array comprises a plurality of subpixels having different colors,
A color gain indicating a characteristic correlation between one reference subpixel and each of the remaining subpixels of each of the pixels; and a reference compensation information for compensating the characteristics of the reference subpixel from a nonvolatile memory;
A second step of detecting sensing compensation information by sensing a characteristic of the reference subpixel among the pixels and detecting reference condition compensation information of the reference subpixel using the reference compensation information and the sensing compensation information;
A third step of detecting condition compensation information for each of the remaining subpixels using the reference condition compensation information and the color gain;
And a fourth step of detecting compensation information for compensating the characteristics of each subpixel using the reference compensation information and the condition compensation information of each subpixel and storing the compensation information in a volatile memory. A method of compensating an OLED display. The method according to claim 1,
The color gain is determined by a ratio between representative condition compensation information of the reference subpixel obtained through modeling and representative condition compensation information of each of the remaining subpixels, and is set in advance before shipment of the product together with the reference compensation information, And the OLED display device is stored in the memory. The method of claim 2,
The exemplary condition compensation information may be condition compensation information for each subpixel or an average value of color compensation information for each color block unit, horizontal line unit, or frame unit including a plurality of subpixels;
Wherein the condition compensation information of each subpixel includes initial compensation information for compensating initial mobility characteristics of each subpixel and sensing compensation information for compensating mobility characteristics of each subpixel sensed through the modeling Wherein the difference is determined as a difference. The method according to claim 1,
Wherein the reference sub-pixel is one of R / G / B sub-pixels or R / G / B / W sub-pixels in each pixel. The method according to claim 1,
Wherein the reference condition compensation information of the reference subpixel is determined as a difference between the reference compensation information of the reference subpixel and the sensing compensation information detected through the sensing of the reference subpixel in the second step;
In the third step, the condition compensation information of each of the remaining subpixels is detected as a product of the reference condition compensation information and the color gain;
Detecting compensation information for each subpixel by summing the reference compensation information and the condition compensation information detected for each subpixel in the fourth step;
Wherein the reference compensation information, the reference condition compensation information, the condition compensation information, and the compensation information are compensation values for compensating mobility characteristics of the corresponding subpixel. The method according to claim 1,
Wherein the first step to the fourth step are performed in units of horizontal lines and are repeated up to the last horizontal line. A display panel including a plurality of subpixels each of which constitutes a pixel array has a different color;
A data driver driving a data line of the display panel and sensing a signal including characteristics of each sub pixel through a sensing line of the display panel to output sensing data;
A gate driver for driving a gate line of the display panel;
And a timing controller for controlling driving of the data driver and the gate driver;
The timing controller, for initial compensation performed at boot time,
A color gain indicating a characteristic correlation between one reference subpixel of each of the pixels and each of the remaining subpixels; and reference compensation information for compensating a characteristic of the reference subpixel from the nonvolatile memory;
Detecting sensing compensation information by sensing characteristics of the reference subpixel among the pixels through the data driver, detecting reference condition compensation information of the reference subpixel using the reference compensation information and the sensing compensation information;
Detecting condition compensation information for each of the remaining subpixels using the reference condition compensation information and the color gain;
And compensating information for compensating the characteristics of each subpixel using the reference compensation information and the condition compensation information of each subpixel, and storing the compensation information in a volatile memory. The method of claim 7,
The color gain is determined by a ratio between representative condition compensation information of the reference subpixel obtained through modeling and representative condition compensation information of each of the remaining subpixels, and is set in advance before shipment of the product together with the reference compensation information, And the OLED display is stored in the memory. The method of claim 8,
The exemplary condition compensation information may be condition compensation information for each subpixel or an average value of color compensation information for each color block unit, horizontal line unit, or frame unit including a plurality of subpixels;
Wherein the condition compensation information of each subpixel includes initial compensation information for compensating initial mobility characteristics of each subpixel and sensing compensation information for compensating mobility characteristics of each subpixel sensed through the modeling And the OLED display is determined as a difference. The method of claim 7,
Wherein the reference sub-pixel is one of R / G / B sub-pixels or R / G / B / W sub-pixels in each pixel. The method of claim 7,
The timing controller
Detecting reference condition compensation information of the reference subpixel by a difference between reference compensation information of the reference subpixel and sensing compensation information detected through sensing of the reference subpixel;
Detecting condition compensation information of each of the remaining subpixels by multiplying the reference condition compensation information by the color gain;
Detecting compensation information for each subpixel by summing the reference compensation information and the condition compensation information detected for each subpixel;
Wherein the reference compensation information, the reference condition compensation information, the condition compensation information, and the compensation information are compensation values for compensating mobility characteristics of the corresponding subpixel. The method of claim 7,
The timing controller
The reference compensation information and the color gain are loaded, the reference condition compensation information detection of the reference subpixel, the condition compensation information detection of the remaining subpixels, and the compensation information detection and storage per the subpixel are performed for each horizontal line , And repeats the above operation to the last horizontal line.

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