KR102542142B1 - Organic light emitting display device and method of manufacturing the same - Google Patents

Abstract

An object of the present invention is to provide an organic light emitting display device and a manufacturing method thereof, in which reference mobilities calculated by reflecting reference threshold voltages of each subpixel are stored. An organic light emitting display device according to the present invention for achieving the above technical problem is a panel having subpixels defined by gate lines and data lines, a data driver supplying data voltages to the data lines, It includes a gate driver supplying gate pulses to the gate lines, a control unit controlling the data driver and the gate driver, and a storage unit storing reference mobilities for correcting input image data corresponding to the sub-pixels. The control unit senses the mobility of the subpixels, compares the sensed mobility with the reference mobility, converts the input image data into image data according to the comparison result, and converts the image data into image data. supplied to the data driver. In each of the reference mobilities, gate-source voltages (Vgs) of driving transistors of other sub-pixels constituting a unit pixel including the first sub-pixel to be calculated have a negative value. is measured in

Description

Organic light emitting display and manufacturing method thereof {ORGANIC LIGHT EMITTING DISPLAY DEVICE AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to an organic light emitting display device capable of performing external compensation through a sensing line and a manufacturing method thereof.

Flat Panel Display Devices (FPDs) are used in various types of electronic products, including mobile phones, tablet PCs, laptops, and the like. Flat panel displays include liquid crystal display devices (LCDs), organic light-emitting diode display devices (OLEDs), and recently, electrophoretic display devices (EPDs). It is widely used.

Of these, the organic light emitting display device (OLED) uses a self-emitting element that emits light by itself, and thus has advantages such as fast response speed, high luminous efficiency, high luminance, and large viewing angle.

In an organic light emitting display device, characteristic variations such as a threshold voltage (Vth) and mobility of a driving transistor occur for each pixel due to process variation, deterioration, and the like. Therefore, the amount of current driving each organic light emitting diode is different, and as a result, a luminance deviation occurs between pixels.

In order to solve the above problem, Korean Patent Laid-open Publication No. 10-2013-0066449 (hereinafter referred to as "prior art document") compensates for the characteristic change of the driving transistor included in each pixel through correction of input image data. An external compensation method is disclosed.

1 is an exemplary view showing the structure of a sub-pixel formed in a panel applied to a conventional organic light emitting display device. In particular, FIG. 1 is an exemplary diagram illustrating a portion of a circuit formed in a sub-pixel of a panel in which external compensation is performed.

In the process of manufacturing a panel using external compensation, reference values for the external compensation are stored in a storage unit.

For example, when the organic light emitting display device is used, the organic light emitting display device measures the threshold voltage or mobility of the driving transistor Tdr included in each pixel of the panel at each preset time. The organic light emitting display device corrects input image data input from an external system using a threshold voltage or mobility measured through the measurement process, and then outputs an image according to the corrected image data.

In this case, a reference threshold voltage and reference mobility for comparison with the threshold voltage or mobility measured through the measurement process are stored in the storage unit of the organic light emitting display device.

The reference threshold voltage and the reference mobility are measured during the manufacturing process of the panel and stored in the storage unit.

However, in a conventional organic light emitting display device, a sensing line connected to the n1 node shown in FIG. 1 is commonly connected to subpixels constituting one unit pixel. Therefore, in the process of manufacturing the panel, when the reference mobility of one subpixel (referred to as a first subpixel) among the subpixels constituting the unit pixel is measured, the n1 of other subpixels is measured. Leakage currents can be generated at the nodes. The leakage current is transmitted through the driving transistor Tdr.

Accordingly, the characteristics of the subpixel may not be accurately reflected in the reference mobility of the first subpixel.

Therefore, when the panel is driven after the organic light emitting display device is manufactured, even if external compensation is performed, stains or the like may occur on the panel.

An object of the present invention proposed to solve the above problems is to provide an organic light emitting display device and a method of manufacturing the same, in which reference mobility calculated by reflecting reference threshold voltages of each subpixel is stored.

An organic light emitting display device according to the present invention for achieving the above technical problem is a panel having subpixels defined by gate lines and data lines, a data driver supplying data voltages to the data lines, It includes a gate driver supplying gate pulses to the gate lines, a control unit controlling the data driver and the gate driver, and a storage unit storing reference mobilities for correcting input image data corresponding to the sub-pixels. The control unit senses the mobility of the subpixels, compares the sensed mobility with the reference mobility, converts the input image data into image data according to the comparison result, and converts the image data into image data. supplied to the data driver. In each of the reference mobilities, gate-source voltages (Vgs) of driving transistors of other sub-pixels constituting a unit pixel including the first sub-pixel to be calculated have a negative value. is measured in

To achieve the above technical problem, a method of manufacturing an organic light emitting display device according to the present invention includes calculating reference threshold voltages of each sub-pixel included in a panel, and performing a reference movement of each sub-pixel using the reference threshold voltages. The method may include calculating degrees, storing the reference threshold voltages and the reference mobility in a storage unit, and mounting the storage unit on the panel. In the step of calculating the reference mobility, gate-source voltages (Vgs) of driving transistors of other subpixels constituting a unit pixel including the first subpixel to be calculated have negative values. In the excitation state, the reference mobility of the first sub-pixel is calculated.

According to the present invention, in the process of manufacturing an organic light emitting display device, when a reference mobility of a first subpixel among subpixels constituting a unit pixel is measured, leakage current in the remaining subpixels constituting the unit pixel is measured. does not occur Accordingly, the reference mobility may accurately reflect the characteristics of the first sub-pixel.

Accordingly, when the organic light emitting display device is driven, input image data corresponding to the first subpixel may be corrected by reflecting the reference mobility, and thus, quality of an image output from the organic light emitting display device may be corrected. this can be improved.

1 is an exemplary view showing the structure of a sub-pixel formed in a panel applied to a conventional organic light emitting display device;
2 is an exemplary diagram schematically illustrating the configuration of an organic light emitting display device according to the present invention;
3 is an exemplary diagram illustrating an arrangement structure of subpixels formed in a panel applied to an organic light emitting display device according to the present invention;
4 is an exemplary view showing the structure of a sub-pixel formed in a panel applied to an organic light emitting display device according to the present invention;
5 is an exemplary view showing the configuration of a control unit applied to an organic light emitting display device according to the present invention;
6 is an exemplary view showing the configuration of a data driver applied to an organic light emitting display device according to the present invention;
7 is an exemplary diagram illustrating waveforms applied to calculation of a reference mobility stored in a storage unit of an organic light emitting display device according to the present invention;

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and those skilled in the art in the art to which the present invention belongs It is provided to fully inform the person of the scope of the invention, and the invention is only defined by the scope of the claims.

In this specification, it should be noted that in adding reference numerals to components of each drawing, the same components have the same numbers as much as possible, even if they are displayed on different drawings.

Since the shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining the embodiment of the present invention are exemplary, the present invention is not limited to the matters shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal precedence relationship is described in terms of 'after', 'following', 'next to', 'before', etc. It can also include non-continuous cases unless is used.

The term 'at least one' should be understood to include all conceivable combinations from one or more related items. For example, 'at least one of the first item, the second item, and the third item' means not only the first item, the second item, or the third item, but also two of the first item, the second item, and the third item. It means a combination of all items that can be presented from one or more.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in an association relationship. may be

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention can be applied to various types of display devices using external compensation. Hereinafter, for convenience of description, an organic light emitting display device will be described as an example of the present invention.

2 is an exemplary diagram schematically illustrating the configuration of an organic light emitting display device according to the present invention, and FIG. 3 is an exemplary diagram illustrating an arrangement structure of subpixels formed in a panel applied to the organic light emitting display device according to the present invention. , FIG. 4 is an exemplary view showing the structure of a sub-pixel formed in a panel applied to an organic light emitting display device according to the present invention.

As shown in FIGS. 2 to 4 , the organic light emitting display device according to the present invention includes subpixels 110 defined by gate lines GL1 to GLg and data lines DL1 to DLd. a panel 100 with data lines DL1 to DLd, a data driver 300 supplying data voltages Vdata to the data lines DL1 to DLd, and a gate driver 200 supplying gate pulses to the gate lines GL1 to GLg. , the controller 400 for controlling the data driver 300 and the gate driver 200, a sensing unit for performing sensing for external compensation on the subpixels and collecting sensing data, and the subpixels ( 110) and a storage unit for storing reference mobilities for correcting input image data. Here, the control unit 400 senses the mobility of the subpixels 110, compares the sensed mobility with the reference mobility, and converts the input image data into image data (Data) according to the comparison result. ), and then supply the image data (Data) to the data driver 300. In each of the reference mobilities, the gate-source voltages (Vgs) of driving transistors of another sub-pixel constituting the unit pixel 120 including the first sub-pixel to be calculated for the reference mobility are negative values. is measured with The sensing unit may be included in the data driver 300 or configured independently of the data driver 300 . Hereinafter, an organic light emitting display device in which the sensing unit is included in the data driver 300 will be described as an example of the present invention. The storage unit may be included in the controller 400 or configured independently of the controller 400 .

First, as shown in FIG. 4 , the panel 100 defines subpixels 110 and a region where the subpixels 110 are formed, and a signal for supplying a driving signal to the pixel driving circuit PDC. Lines DL, GL, PLA, PLB, SL, and SPL are formed.

A data voltage is supplied to the data line DL, a gate pulse is supplied to the gate line GL, and a first driving power EVDD is supplied to the first driving power line PLA. 2 The second driving power source EVSS is supplied to the driving power line PLB, the reference voltage Vref is supplied to the sensing line SL, and the sensing transistor Tsw2 to the sensing pulse line SPL. ) is supplied with a sensing pulse (SP) for turning on or off.

At least three of the sub-pixels 110 form one unit pixel 120 . In the following description, four sub-pixels 110 (red sub-pixel R, white sub-pixel W, green sub-pixel G and blue sub-pixel B) are described as shown in FIG. 3 . The present invention will be described taking a case in which this one unit pixel 120 is formed as an example. In particular, in FIG. 3 , two unit pixels 120 composed of a red sub-pixel R, a white sub-pixel W, a green sub-pixel G, and a blue sub-pixel B are shown.

In this case, one sensing line SL may be commonly connected to the unit pixel 120 . Therefore, when d data lines DL1 to DLd are formed on the horizontal line of the panel 100, the number k of the sensing lines SL becomes d/4. However, the sensing line may be provided for each sub-pixel.

As shown in FIG. 4 , each of the plurality of subpixels 110 may include a pixel driving circuit (PDC) and an organic light emitting diode (OLED).

For example, each of the subpixels 110 includes a switching transistor Tsw1 connected to a gate line GL and a data line DL, an organic light emitting diode (OLED) that outputs light, and the switching transistor Tsw1. and a driving transistor Tdr and a sensing transistor Tsw2 which control the amount of current output to the organic light emitting diode according to the data voltage Vdata transmitted through . The sensing transistor Tsw2 is connected to a first node n1 between the driving transistor Tdr and the organic light emitting diode OLED and to a sensing line SL, and is turned on or off by a sensing pulse SP. In the sensing period of the blank period, the characteristics of the driving transistor are sensed. A second node n2 connected to the gate of the driving transistor is connected to the switching transistor Tsw1. A storage capacitance Cst is formed between the second node n2 and the first node n1. Components other than the organic light emitting diode (OLED) form the pixel driving circuit (PDC).

In the above description, the structure of the sub-pixel 110 for performing external compensation has been described with reference to FIG. 4, but the sub-pixel 110 may be formed in various structures other than the structure shown in FIG. . A specific structure of a sub-pixel for performing extrinsic compensation and a specific method of extrinsic compensation are outside the scope of the present invention. Therefore, an example of a sub-pixel for extrinsic compensation and an extrinsic compensation method are briefly described or omitted with reference to FIGS. 3 and 4 .

For example, an object of the present invention is to provide an organic light emitting display device and a manufacturing method thereof, in which reference mobilities calculated by reflecting threshold voltages of each subpixel 110 are stored. Therefore, a subpixel structure for extrinsic compensation and a method for performing extrinsic compensation can be selected from various subpixel structures and extrinsic compensation methods currently proposed for extrinsic compensation. For example, structures and methods disclosed in a number of published patents including Patent Publication No. 10-2013-0066449 may be applied to the structure of the subpixel for the external compensation and the method for performing the external compensation. In addition, the invention disclosed in Application No. 10-2013-0150057 and Application No. 10-2013-0149213 filed by the present applicant may be applied.

In addition, the present invention calculates the reference mobility using the reference threshold voltage calculated by various methods currently used, and the method of calculating the reference threshold voltage is outside the scope of the present invention. Therefore, a method of calculating the reference threshold voltage will be briefly described.

Second, the gate driver 200 sequentially generates gate pulses in response to the gate control signal GCS supplied from the controller 400 and sequentially supplies them to the gate lines GL1 to GLg. The gate driver 200 may be directly formed on the panel 100 together with the thin film transistor formation process of each sub-pixel 110, or may be formed in the form of an integrated circuit (IC) and mounted on the panel. A type in which the gate driver 200 is directly formed on the panel 100 is referred to as a Gate In Panel (GIP) type.

Third, the control unit 400 uses a gate control signal (GCS) for controlling driving of the gate driver 200 and driving of the data driver 300 based on a timing synchronization signal (TSS) input from an external system. Each generates a data control signal (DCS) for controlling. A specific configuration and function of the controller 400 will be described in detail with reference to FIG. 5 .

Fourth, the data driver 300 is connected to the data lines DL1 to DLd and the sensing lines SL. A specific configuration and function of the data driver 300 will be described in detail with reference to FIG. 6 .

Fifth, the sensing unit collects sensing data by performing sensing for external compensation on the sub-pixels. The sensing unit will be described with reference to FIG. 6 .

5 is an exemplary view showing the configuration of a control unit applied to an organic light emitting display device according to the present invention.

The controller 400 transmits, to the data driver 300 , image data for sensing to be supplied to pixels formed on a horizontal line where external compensation is performed. Sensing for the external compensation is performed in the blank period between frames. However, the sensing for external compensation may be performed during a display period during which an image is output. Hereinafter, for convenience of explanation, an organic light emitting display device in which sensing for the external compensation is performed in the blank period will be described as an example of the present invention.

During the sensing period, the control unit 400 calculates the external compensation value based on the sensing data Sdata provided from the sensing unit included in the data driver 300 to determine the external compensation value. stored in the storage unit 450.

In order to perform the above function, the control unit 400, as shown in FIG. 5, uses the timing synchronization signal (TSS) transmitted from the external system to input image data (ID) transmitted from the external system. ) using the external compensation value, and a data aligning unit 430 supplying the rearranged compensation image data to the data driver 300, and the gate control signal (GCS) using the timing synchronization signal. and a control signal generator 420 for generating the data control signal DCS and the power control signal PCS, and the sensing data Sdata transmitted from the sensing unit included in the data driver 300. a calculation unit 410 for calculating the external compensation value for compensating for a change in the characteristics of the driving transistor formed in each of the pixels using the data, a storage unit 450 for storing the external compensation value, and the compensation image An output unit 440 for outputting data and various control signals DCS and GCS to the data driver 300 or the gate driver 200 is included.

The calculation unit 410 may be formed in the control unit 400 or may be formed independently of the control unit 400 . Hereinafter, an organic light emitting display device according to the present invention will be described taking a case in which the calculator 410 is included in the control unit 400 as shown in FIG. 5 as an example.

Reference mobilities and reference threshold voltages for correcting input image data corresponding to the subpixels 110 are stored in the storage unit 450 . The storage unit 450 may be manufactured independently from elements constituting the control unit 400 and then mounted on the panel or included in the control unit 400 .

The reference mobility values and the reference threshold voltages are calculated in the manufacturing process of the organic light emitting display device according to the present invention and then stored in the storage unit 450 .

In each of the reference mobilities, the gate-source voltages (Vgs) of driving transistors of another sub-pixel constituting the unit pixel 120 including the first sub-pixel to be calculated for the reference mobility are negative values. is measured with A specific method for calculating the reference mobility is described in detail with reference to FIG. 7 .

When the organic light emitting display device is actually driven by a user, the controller 400 senses the mobility of the subpixels 110, compares the sensed mobility with the reference mobility, and compares the result of the comparison. According to this, after converting the input image data into image data (Data), the image data (Data) is supplied to the data driver 300. The data driver 300 converts the image data into data voltages and outputs them to the data lines DL1 to DLd.

6 is an exemplary view showing the configuration of a data driver applied to an organic light emitting display device according to the present invention.

The data driver 300 is connected to the data lines DL1 to DLd and the sensing lines SL1 to SLk. As shown in FIG. 4 , when the data driver 300 includes the data voltage output unit 310 and the sensing unit 320, the data voltage output unit 310 is connected to the data line DL. , and the sensing unit 320 is connected to the sensing lines SL.

The data voltage output unit 310 converts the compensation image data into the data voltage Vdata and outputs the data voltage to the data line.

The sensing unit 320 supplies a reference voltage to the subpixels during the sensing period, and then generates the sensing data Sdata by using a signal transmitted from the subpixels. The sensing data Sdata is transmitted to the controller 400 .

The controller 400 converts the input image data into the image data using the sensing data Sdata.

7 is an exemplary diagram illustrating waveforms applied to calculation of a reference mobility stored in a storage unit of an organic light emitting display device according to the present invention. Hereinafter, an organic light emitting display device and a manufacturing method thereof according to the present invention will be described with reference to FIGS. 2 to 7 .

The configuration of the organic light emitting display device according to the present invention described above is briefly summarized as follows.

The organic light emitting display device includes the panel 100, the data driver 300, the gate driver 200, the controller 400, the sensing unit 320, and input image data corresponding to the subpixels. and the storage unit 450 for storing reference mobility for correcting the .

When the organic light emitting display device is driven, a display period in which an image is displayed and a blank period in which an image is not displayed are repeated.

During the blank period, the controller 400 drives the gate driver 200 , the data driver 300 , and the sensing unit 320 to sense the mobilities of the subpixels 110 .

The controller 400 compares the sensed degrees of mobility with the reference degrees of mobility stored in the storage 450 . The controller 400 converts the input image data into image data (Data) according to the comparison result. The controller 400 supplies the image data to the data driver 300 .

The reference mobility values are calculated in the manufacturing process of the organic light emitting display device and then stored in the storage unit 450 .

Each of the reference mobilities is determined by the gate-source voltages (Vgs) of driving transistors of another sub-pixel 110 constituting the unit pixel 120 including the first sub-pixel for which the reference mobility is to be calculated. Measured with negative values.

The reference mobilities are calculated by reflecting the threshold voltages of each sub-pixel 110 .

As shown in FIG. 4 , each of the subpixels 110 includes the switching transistor Tsw1 connected to a gate line and a data line, an organic light emitting diode (OLED) that outputs light, and the switching transistor Tsw1. A driving transistor Tdr that controls the amount of current output to the organic light emitting diode OLED according to a data voltage transmitted through the driving transistor Tdr and a first node between the driving transistor Tdr and the organic light emitting diode OLED ( n1) and the sensing line SL, turned on or off by the sensing pulse SP, and sensing the characteristics of the driving transistor Tdr during the sensing period of the blank period. do.

In the manufacturing process of the organic light emitting display device, during the first period T1 of the reference mobility measuring period T for measuring the reference mobility, another unit pixel constituting the first subpixel is included. First voltages Vrpre are supplied to the first nodes n1 through the sensing transistors of the subpixels.

After the first voltage Vrpre is supplied during the first period T1, a second voltage Vspre lower than the first voltage Vrpre is supplied to the first nodes n1.

During the second period T2 following the first period T1 during the reference mobility measurement period T, the reference mobility of the driving transistor Tdr of the first subpixel is calculated.

Hereinafter, a method of manufacturing the organic light emitting display device according to the present invention described above will be described. In particular, a method of measuring the reference mobility will be described in detail below.

A method of manufacturing an organic light emitting display device according to the present invention includes manufacturing the panel 100 including gate lines, data lines, and the subpixels, each subpixel ( 110), calculating reference mobilities of each sub-pixel using the reference threshold voltages, and storing the reference threshold voltages and the reference mobilities in the storage unit 450. and mounting the storage unit 450 on the panel.

In the step of manufacturing the panel 100, processes currently used for manufacturing the panel may be applied as they are.

In the step of calculating the reference threshold voltages, currently used methods for calculating reference threshold voltages in an organic light emitting display device may be applied as they are.

In the step of mounting the storage unit 450 on the panel, a process of mounting the storage unit 450 on the panel in the current organic light emitting display device may be applied as it is.

In the step of calculating the reference mobility, gate-source voltages (Vgs) of driving transistors of other sub-pixels constituting the unit pixel including the first sub-pixel to be calculated have negative values. In the excitation state, the reference mobility of the first subpixel is calculated.

Hereinafter, the step of calculating the reference mobilities will be described in detail.

First, after the panel 100 is manufactured, the panel 100 is mounted on a measuring device such as an auto probe to measure the reference mobility.

Second, threshold voltages of the sub-pixels of the panel 100 that have already been measured prior to the measurement of the reference mobility are stored in the memory of the measuring device.

Third, when the reference mobility measuring period T for measuring the reference mobility arrives, during the first period T1 of the reference mobility measuring period T, the unit including the first sub-pixel The first voltages Vrpre are supplied to sources of driving transistors Tdr of other sub-pixels constituting the pixel 120 . In this case, the first voltage Vrpre is also supplied to the source of the driving transistor Tdr of the first subpixel.

For example, as shown in FIG. 3, the unit pixel 120 is composed of a red sub-pixel (R), a white sub-pixel (W), a green sub-pixel (G), and a blue sub-pixel (B), When the reference mobility of the driving transistor Tdr of the white sub-pixel W is measured, when the first period T1 arrives, as shown in FIG. 7 , during the initial period, various signals are supplied to the pixel driving circuit PDC of the red sub-pixel (R), the white sub-pixel (W), the green sub-pixel (G) and the blue sub-pixel (B). Hereinafter, the white sub-pixel W is referred to as a first sub-pixel, and the remaining red sub-pixels R, white sub-pixels W, green sub-pixels G, and blue sub-pixels B are referred to as second sub-pixels. are called pixels.

First, during the initial period (Initial), the gate line voltage Vgl having a low value is supplied to the gate line GL, and the sensing pulse line voltage Vspl having a low value is supplied to the sensing pulse line SPL. ) is supplied, and the first voltage Vrpre having a high value is supplied to the sensing line SL. Since the first voltage Vrpre and the second voltage Vspre are voltages supplied through the sensing line SL, when the first voltage Vrpre is supplied, the second voltage Vspre not supplied

The first voltage Vrpre causes the gate-source voltages Vgs of the driving transistors of the second sub-pixel to have a negative value, and the gate-source voltage Vgs of the driving transistor of the first sub-pixel It is the voltage that causes it to have a positive value.

For example, the first voltage Vrpre may be a reference threshold voltage Vth of the first sub-pixel. Accordingly, the first voltage Vrpre is greater than 0V. More specifically, the first voltage Vrpre may be about 2.5V. The first voltage Vrpre is greater than the value of the second voltage Vspre, for example, 0V.

In this case, a data voltage obtained by adding the threshold voltage Vth and the data voltage for sensing is supplied to the data line DL connected to the first subpixel. Also, a black data voltage, for example, a data voltage of 0.5V is supplied to the data lines DL connected to the second subpixels.

As described above, a voltage of 2.5V (Vn1 (= Vrpre)) is supplied to the source of the driving transistor Tdr of the second subpixel, that is, to the first node n1, and the driving transistor Tdr ) is supplied with a data voltage of 0.5V. Accordingly, the gate-source voltage (Vgs) of the second sub-pixel becomes -2.0V (= 0.5V-2.5V).

Since the gate-source voltage Vgs of the driving transistor of the second subpixel has a negative value (-2.0V), the driving transistors Tdr of the second subpixel are not turned on. Accordingly, leakage current does not flow through the driving transistors Tdr of the second sub-pixels.

Conventionally, in the first period T1, a voltage of 0V corresponding to the second voltage Vspre is supplied to sources of driving transistors of the second subpixels, that is, to the first node n1. Accordingly, the gate-source voltage of the driving transistors of the second sub-pixels had a positive value of 0.5V. Accordingly, the driving transistors of the second sub-pixels are turned on, and leakage current may flow.

However, according to the present invention, since the first voltage Vrpre including the reference threshold voltage of the first subpixel is supplied to the first node in the initial period of the first period T1, the first During the period T1, no leakage current is generated in the second sub-pixels. Accordingly, only the current flowing through the first sub-pixel is considered in the reference mobility of the first sub-pixel calculated through subsequent processes. Accordingly, the reference mobility of the first subpixel may be a value considering characteristics of only the first subpixel.

In this case, as described above, 2.5V is supplied to the first node n1 of the first subpixel, and the sensing data is supplied to the threshold voltage (2.5V) to the data line of the first subpixel. The data voltage in which the voltages are summed is supplied. Accordingly, the gate-source voltage Vgs of the driving transistor Tdr of the first subpixel may be the sensing data voltage. Since the sensing data voltage has a value greater than 0V, the gate-source voltage Vgs of the driving transistor Tdr of the first subpixel has a positive value. Therefore, during the initial period (Initial) of the first period (T1), the driving transistor (Tdr) of the first sub-pixel is turned on, and a current flows through the driving transistor (Tdr).

Next, after the first voltage Vrpre is supplied during the first period T1, a second voltage Vspre lower than the first voltage Vrpre is supplied to the sources.

For example, during the initial period of the first period T1 and a partial period of a program period following the initial period, the sub-pixels constituting the unit pixel may The first voltage Vrpre is supplied to the sensing lines SL.

Before the program period (Program) ends, the second voltage (Vspre) is supplied to the sensing lines (SL) of the sub-pixels. Accordingly, the second voltage Vspre is supplied to the first node n1 of the first subpixel and the first nodes n1 of the second subpixels. Accordingly, the same voltage Vn1 (=Vspre) is supplied to the first nodes n1 of the first sub-pixel and the second sub-pixel. Accordingly, the first sub-pixel and the second sub-pixel have the same condition.

Finally, the reference mobility for the first sub-pixel is calculated during a second period T2 following the first period T1 during the reference mobility measurement period T.

As described above, a currently used method may be applied to the method of calculating the reference mobility.

For example, in the sensing period (Sensing) of the second period (T2), the black data voltage (BLK) is supplied to the data lines of the first subpixel and the second subpixel, and the gate line (GL) A gate line voltage Vgl having a low value is supplied to , and a sensing pulse line voltage Vspl having a high value is supplied to the sensing pulse line SPL.

During the sampling period (Sampling) that comes after the sensing period (Sensing) in the second period (T2), a gate line voltage (Vgl) (gate pulse) having a high value is supplied to the gate line (GL). , the sensing pulse line voltage Vslp having a high value is supplied to the sensing pulse line SPL, and the measuring device generates a sampling voltage Vsamp.

Until the sensing period (Sensign) of the second period (T2), the current charged in the first node (n1) of the first sub-pixel is generated when the sampling voltage (Vsamp) is generated by the measuring device, It is supplied to the measuring device through the sensing line SL. In this case, the voltage of the first node n1 of the first sub-pixel gradually increases as shown in FIG. 7 .

To elaborate, in the reference mobility measuring period T, only the current generated in the first sub-pixel is supplied to the measuring device through the sensing line SL. The measuring device may calculate the reference mobility of the driving transistor Tdr of the first subpixel by measuring the current. Therefore, the reference mobility of the first subpixel calculated by the measurement device may reflect only the characteristics of the first subpixel.

In the present invention, as described above, when the gate-source voltages of the driving transistors of the other sub-pixels, that is, the second sub-pixels have a negative value, the driving transistor of the first sub-pixel is turned on A current flows through the driving transistor of the first subpixel. However, since the gate-source voltages of the driving transistors of the second subpixels have a negative value, current does not flow through the driving transistors of the second subpixels.

Accordingly, in a state in which leakage current is not generated from the second subpixels, the reference mobility of the first subpixel may be calculated only by the current of the first subpixel. Accordingly, the reference mobility of the first subpixel may be a value reflecting only the characteristics of the first subpixel.

Those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing its technical spirit or essential features. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention. do.

100: panel 200: gate driver
300: data driver 400: control unit
110: sub pixel 120: unit pixel
410: calculation unit 420: control signal generation unit
430: data sorting unit 440: output unit
450: storage unit 310: data voltage output unit
320: sensing unit

Claims (6)

a panel having sub-pixels defined by gate lines and data lines;
a data driver supplying data voltages to the data lines;
a gate driver supplying gate pulses to the gate lines;
a control unit controlling the data driver and the gate driver; and
a storage unit for storing reference mobilities for correcting input image data corresponding to the sub-pixels;
The control unit senses the mobility of the subpixels, compares the sensed mobility with the reference mobility, converts the input image data into image data according to the comparison result, and converts the image data into image data. supplied to the data driver,
In each of the reference mobilities, a gate-source voltage (Vgs) of a driving transistor of a first subpixel whose reference mobility is to be calculated has a positive value, and constitutes a unit pixel including the first subpixel. An organic light emitting display device in which gate-source voltages (Vgs) of driving transistors of other sub-pixels having a negative value are measured. According to claim 1,
The reference mobility is calculated by reflecting reference threshold voltages of each sub-pixel. According to claim 1,
Each of the sub-pixels,
a switching transistor connected to the gate line and the data line;
an organic light emitting diode that outputs light;
a driving transistor controlling the amount of current output to the organic light emitting diode according to the data voltage transmitted through the switching transistor; and
A sensing transistor connected to a first node and a sensing line between the driving transistor and the organic light emitting diode, turned on or off by a sensing pulse, and sensing characteristics of the driving transistor during a sensing period of a blank period; ,
During the first period of the reference mobility measuring period for measuring the reference mobility, a first node is connected to the first nodes through the sensing transistors of other subpixels constituting a unit pixel including the first subpixel. Voltages are supplied, and after the first voltage is supplied during the first period, a second voltage lower than the first voltage is supplied to the first nodes, and after the first period during the reference mobility measurement period The organic light emitting display device wherein the reference mobility of the driving transistor of the first sub-pixel is calculated during a second period of time. Calculating reference threshold voltages of each sub-pixel provided in the panel;
calculating reference mobilities of each sub-pixel using the reference threshold voltages;
storing the reference threshold voltages and the reference mobility in a storage unit; and
Mounting the storage unit to the panel,
Calculating the reference mobility,
A gate-source voltage (Vgs) of a driving transistor of a first subpixel for which the reference mobility is to be calculated has a positive value, and a driving transistor of another subpixel constituting a unit pixel including the first subpixel. and calculating the reference mobility of the first sub-pixel in a state in which gate-source voltages (Vgs) of Vgs have a negative value. According to claim 4,
When the gate-source voltages (Vgs) of the driving transistors of the other subpixels have a negative value, the driving transistor of the first subpixel is turned on and current flows through the driving transistor of the first subpixel. A method for manufacturing a display device. According to claim 4,
Calculating the reference mobility,
supplying first voltages to sources of driving transistors of other subpixels constituting a unit pixel including the first subpixel during a first period of a reference mobility measurement period for measuring the reference mobility; ;
supplying a second voltage lower than the first voltage to the sources after the first voltage is supplied during the first period; and
and calculating the reference mobility for the first sub-pixel during a second period following the first period during the reference mobility measurement period.

Images