Display manufacturing system and driving method of the same

A display manufacturing system includes: a plurality of display devices, each including a display panel which displays an image; a driving voltage measurer which calculates a saturation voltage corresponding to a luminance of the image displayed on the display panel by changing a driving power voltage for driving the display panel; and a processor which calculates a current density and a degradation weight value based on the saturation voltage, and controls the display panel included in each of the plurality of display devices based on the current density and the degradation weight value.

This application claims priority to Korean patent application 10-2021-0097340, filed on Jul. 23, 2021, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which in its entirety is herein incorporated by reference.

BACKGROUND

The disclosure generally relates to a display manufacturing system and a driving method of the display manufacturing system.

2. Related Art

With the development of information technologies, the importance of a display device which is a connection medium between a user and information increases. Accordingly, display devices such as a liquid crystal display device and an organic light emitting display device are widely used in various fields.

Conventionally, various techniques for manufacturing display device by predicting a lifetime distribution of display devices and compensating for the predicted lifetime distribution of display devices have been studied to improve display quality.

SUMMARY

When predicting a lifetime distribution of display devices and compensating for the predicted lifetime distribution thereof to improve display quality, it may be desired to rapidly predict the lifetime distribution of the display devices in a process of manufacturing the display devices to reduce manufacturing time and improve productivity.

Embodiments provide a display manufacturing system and a driving method of the display manufacturing system, in which a lifetime distribution is predicted through measurement of a driving power voltage in a process of manufacturing display devices, and an afterimage of the manufactured display devices is compensated by using the predicted lifetime distribution.

Embodiments also provide a display manufacturing system and a driving method of the display manufacturing system, in which a lifetime distribution is predicted in a process of manufacturing display devices, thereby reducing manufacturing time and improving productivity.

In accordance with an embodiment of the disclosure, a display manufacturing system includes: a plurality of display devices, each including a display panel which displays an image; a driving voltage measurer which calculates a saturation voltage corresponding to a luminance of the image displayed on the display panel by changing a driving power voltage for driving the display panel; and a processor which calculates a current density and a degradation weight value, based on the saturation voltage, and controls the display panel included in each of the plurality of display devices based on the current density and the degradation weight value.

In an embodiment, the saturation voltage may be a voltage corresponding to a point at which a variation of the luminance is changed as the driving power voltage connected to a light emitting element of the display panel is changed.

In an embodiment, the processor may include: a memory which pre-stores a plurality of parameters for calculating the current density and the degradation weight value; and a calculator which calculates the current density and the degradation weight value, based on the plurality parameters.

In an embodiment, the calculator may calculate the degradation weight value, based on a center value of the current density of the display panel included in each of the plurality of display devices and the current density of a target display panel.

In an embodiment, the calculator may calculate the degradation weight value, based on a center value of the luminance of the display panel included in each of the plurality of display devices and the luminance of the target display panel.

In an embodiment, the memory may pre-store the current density corresponding to a change in driving voltage of the light emitting element of the display panel. In such an embodiment, the driving voltage of the light emitting element may be a voltage higher by a threshold voltage of the light emitting element than the driving power voltage.

In an embodiment, the driving voltage of the light emitting element may be a voltage corresponding to at a point at which a current flowing through the light emitting element and a current flowing through a driving transistor of the display panel are the same as each other.

In an embodiment, the calculator may calculate the current density corresponding to the saturation voltage by using the current density pre-stored in the memory.

In an embodiment, the image may be displayed by using at least one of a first color, a second color, and a third color. In such an embodiment, the current density may be calculated when the image is displayed by using any one of the first color, the second color, and the third color.

In an embodiment, the display panel may include a plurality of pixels. In such an embodiment, the calculator may calculate the current density and the degradation weight value, based on a center value of the current density of the plurality of pixels and a center value of the current density calculated in a target pixel.

In accordance with an embodiment of the disclosure, a method of driving a display manufacturing system including a plurality of display devices, a driving voltage measurer, and a processor, the method includes: displaying, by a display panel, an image, where the display panel is included in each of the plurality of display devices; calculating, by the driving voltage measurer, a saturation voltage corresponding to a luminance of the image displayed on the display panel by changing a driving power voltage for driving the display panel; and calculating, by the processor, a current density and a degradation weight value, based on the saturation voltage, and controlling the display panel included in each of the plurality of display devices based on the current density and the degradation weight value.

In an embodiment, the calculating the saturation voltage corresponding to the luminance may include determining, by the driving voltage measurer, as the saturation voltage, a voltage corresponding to a point at which a variation of the luminance is changed as the driving power voltage connected to a light emitting element of the display panel is changed.

In an embodiment, the processor may include a memory and a calculator. In such an embodiment, the calculating, by the processor, the current density and the degradation weight value, based on the saturation voltage may include: pre-storing, by the memory, a plurality of parameters for calculating the current density and the degradation weight value; and calculating, by the calculator, the current density and the degradation weight value, based on the plurality of parameters.

DETAILED DESCRIPTION

FIG.1is a diagram illustrating a display manufacturing system in accordance with an embodiment of the disclosure.FIG.2is a diagram illustrating a display device in accordance with an embodiment of the disclosure. Hereinafter, embodiments of the display manufacturing system and the display device will be described in detail with reference toFIGS.1and2.

Referring toFIG.1, an embodiment of the display manufacturing system1(or a system for manufacturing a display device) in accordance with the disclosure may include a plurality of display devices10(1) to10(N), a luminance measurer20, a driving voltage measurer30, and a processor40.

Referring toFIG.2, although an embodiment of a display device10(1) is illustrated, other display devices10(2) to10(N) are identical to the display device10(1), and therefore, any repetitive detailed descriptions of the other display devices10(2) to10(N) will be omitted.

Referring toFIGS.1and2, an embodiment of the display device10(1) may include a display panel PNL including a timing controller11, a data driver12, a scan driver13, a pixel unit14, and an emission driver15.

In an alternative embodiment, the display panel PNL may be defined by at least some components among the timing controller11, the data driver12, the scan driver13, the pixel unit14, and the emission driver15.

The timing controller11may receive an external input signal from the processor40. The external input signal may include a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, RGB data, a data control signal Dcon, and the like.

The vertical synchronization signal may include a plurality of pulses, and indicate that a previous frame period is ended and a current frame period is started with respect to a point at which each of the pulses is generated. An interval between adjacent pulses of the vertical synchronization signal may correspond to one frame period. The horizontal synchronization signal may include a plurality of pulses, and indicate that a previous horizontal period is ended and a new horizontal period is started with respect to a point at which each of the pulses is generated. An interval between adjacent pulses of the horizontal synchronization signal may correspond to one horizontal period.

The data enable signal may indicate that RGB data is supplied in a horizontal period. The RGB data may be supplied in units of pixel rows in horizontal periods, corresponding to the data enable signal. RGB data corresponding to one frame may be referred to as one input image. The data control signal Dcon may include data about a degradation weight value B (seeFIG.8) of each of the plurality of display devices10(1) to10(N).

In an embodiment of the disclosure, the data control signal Dcon may include data (or a degradation weight value B) for compensating for a lifetime characteristic (e.g., afterimage occurrence according to display use time) between the plurality of display devices10(1) to10(N) produced based on a driving voltage Vel (seeFIG.5) of the plurality of display devices10(1) to10(N) in a manufacturing process of the plurality of display devices10(1) to10(N). The timing controller11may output a control signal for controlling the data driver12, based on the data control signal Dcon.

In an embodiment, the data control signal Dcon may be supplied from the processor40in a manufacturing process of the display device10(1). In such an embodiment, the data control signal Dcon is not supplied to the timing controller11in a period in which the display device10(1) normally implements an image. In an embodiment, the timing controller11may store information on the degradation weight value B included in the data control signal Dcon supplied from the processor40in the manufacturing process, and control data and the like by using the stored information on the degradation weight value B.

The data driver12may provide pixels PXij with data signals (or data voltages) corresponding to grayscales of an input image. In an embodiment, for example, the data driver12may sample grayscales by using a clock signal. The data driver12may apply data signals corresponding to the sampled grayscales to output lines D1to Dn. Here, n may be an integer greater than 0.

The data driver12may provide corrected data voltages to the pixels PXij, corresponding to the control signal output from the timing controller11. The corrected data voltages may correspond to a voltage obtained by adding the degradation weight value B to a data voltage value output from the data driver12in a process of measuring the driving voltage Vel of the plurality of produced display devices10(1) to10(N).

The scan driver13may receive a clock signal, a scan start signal, and the like from the timing controller11, and generate scan signals to be provided to scan lines SL1to SLm.

The pixel unit14may include pixels PXij. Each pixel PXij may be connected to a corresponding data line among data lines DL1to DLn and a corresponding scan line among the scan lines SL1to SLm. Here, i and j may be integers greater than 0. In addition, m may be an integer greater than 0.

The emission driver15may receive a clock signal, an emission stop signal, and the like from the timing controller11, and generate emission control signals to be provided to emission control lines E1to Em. Each pixel PXij may further include a transistor connected to a corresponding emission control line among the emission control lines E1to Em. The transistor may be turned off during a data write period of each pixel PXij to suspend light emission of the pixel PXij.

The luminance measurer20may be separately provided at the outside of the plurality of display devices10(1) to10(N). The luminance measurer20may measure a luminance LUM (seeFIG.6) of an image displayed on the display panel PNL while a second driving power voltage ELVSS (seeFIG.3) for driving the pixel unit14provided in each of the plurality of display devices10(1) to10(N) is changed.

The driving voltage measurer30may measure the second driving power voltage ELVSS which is changed. The driving voltage measurer30may calculate a saturation voltage Vsat of a light emitting element EL (seeFIG.3) provided in each of the plurality of display devices10(1) to10(N), corresponding to the luminance LUM measured by the luminance measurer20. The process in which the driving voltage measurer30calculates the saturation voltage Vsat of the light emitting element EL will be described in detail below with reference toFIG.6.

The processor40may include a memory400and a calculator401.

The memory400may pre-store a plurality of parameters for calculating a current density CDT (seeFIG.7) by using the saturation voltage Vsat calculated by the driving voltage measurer30. The memory400may pre-store a plurality of parameters for calculating the degradation weight value B by using the current density CDT.

The calculator401may calculate the current density CDT by using the plurality of parameters stored in the memory400and the saturation voltage Vsat calculated by the driving voltage measurer30. The calculator401may calculate the degradation weight value B by using the plurality of parameters stored in the memory400and the current density CDT.

The processor40may output, to the timing controller11, the control signal Dcon to which the degradation weight value B calculated by the calculator401is reflected.

FIG.3is a diagram illustrating an embodiment of the pixel included in the display device shown inFIG.2.

For convenience of illustration and description, a pixel which is located on an i-th horizontal line and is connected to a j-th data line DLj is illustrated inFIG.3.

Referring toFIG.3, an embodiment of the pixel PXij provided in the display device10(1) may include a light emitting element EL, transistors T1to T7, and a storage capacitor Cst. However, the structure of the pixel PXij is not limited to the structure show inFIG.3, and may be variously modified. Hereinafter, an embodiment of the pixel PXij having the structure shown inFIG.3will be described in detail.

In such an embodiment, a first electrode (e.g., an anode or cathode electrode) of the light emitting element EL may be connected to a fourth node N4, and a second electrode (e.g., a cathode or anode electrode) of the light emitting element EL may be connected to a second driving power voltage ELVSS. The light emitting element EL generates light with a predetermined luminance, corresponding to an amount of current supplied from a first transistor T1.

In an embodiment, the light emitting element EL may be an organic light emitting diode including an organic emitting layer. In an alternative embodiment, the light emitting element EL may be an inorganic light emitting element including or formed of an inorganic material. Alternatively, the light emitting element EL may have a form in which inorganic light emitting elements are connected to each other in parallel and/or series between the second driving power voltage ELVSS and the fourth node N4.

A first electrode of the first transistor T1(or driving transistor) may be connected to a second node N2, and a second electrode of the first transistor T1may be connected to a third node N3. A gate electrode of the first transistor T1may be connected to a first node N1. The first transistor T1may control a driving current IES flowing from a first driving power voltage ELVDD to the second driving power voltage ELVSS via the light emitting element EL, based on a voltage of the first node N1. The first driving power voltage ELVDD may be set as a voltage higher than that of the second driving power voltage ELVSS.

A second transistor T2may be connected between the j-th data line DLj and the second node N2. A gate electrode of the second transistor T2may be connected to an i-th scan line SLi. The second transistor T2may be turned on by a gate-on level of a scan signal supplied to the i-th scan line SLi, to electrically connect the j-th data line DLj and the second node N2to each other.

A third transistor T3may be connected between the first electrode of the light emitting element EL (i.e., the fourth node N4) and a power line PL through which an initialization voltage Vint is supplied. A gate electrode of the third transistor T3may be connected to the i-th scan line SLi. The third transistor T3may be turned on by the gate-on level of the scan signal supplied to the i-th scan line SLi, to supply the initialization voltage Vint to the first electrode of the light emitting element EL (i.e., the fourth node N4).

A fourth transistor T4may be connected between the first node N1and the power line PL. A gate electrode of the fourth transistor T4may be turned on by a gate-on level of a scan signal supplied to an (i−1)-th scan line SLi−1, to supply the initialization voltage Vint to the first node N1.

A fifth transistor T5may be connected between the first driving power voltage ELVDD and the second node N2. A gate electrode of the fifth transistor T5may be connected to an i-th emission control line Ei. The fifth transistor T5may be turned on by a gate-on level of an emission control signal supplied to the i-th emission control line Ei.

A sixth transistor T6may be connected between the second electrode of the first transistor T1(i.e., the third node N3) and the first electrode of the light emitting element EL (i.e., the fourth node N4). A gate electrode of the sixth transistor T6may be connected to the i-th emission control line Ei. The sixth transistor T6may be turned on by the gate-on level of the emission control signal supplied to the i-th emission control line Ei. Therefore, the fifth transistor T5and the sixth transistor T6may be simultaneously controlled by the emission control signal.

A seventh transistor T7may be connected between the second electrode of the first transistor T1(i.e., the third node N3) and the first node N1. A gate electrode of the seventh transistor T7may be connected to the i-th scan line SLi. The seventh transistor T7may be turned on by the gate-on level of the scan signal supplied to the i-th scan line SLi, to electrically connect the second electrode of the first transistor T1and the first node N1to each other. When the seventh transistor T7is turned on, the first transistor T1may be connected in a diode form.

The storage capacitor Cst may be connected between the first driving power voltage ELVDD and the first node N1.

FIG.4is a diagram illustrating the pixel unit included in the display device shown inFIG.2.

Referring toFIG.4, an embodiment of the pixel unit14may include a plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33. Although an embodiment where the pixel unit14includes 9 pixels is illustrated inFIG.4, the disclosure is not limited thereto.

In an embodiment, the luminance measurer20may measure a luminance of a central portion of the pixel unit14, and measure a driving voltage Vel of a light emitting element EL provided in a pixel PX22included in the central portion, to predict a lifetime characteristic of the plurality of display devices10(1) to10(N) produced in a manufacturing process of the plurality of display devices10(1) to10(N) and compensate for an afterimage occurring according to display use time. In an embodiment shown inFIG.4, the pixel PX22is the central portion of the pixel unit14.

Hereinafter, in embodiments shown inFIGS.4to8, it is assumed that only one pixel PX22(or central pixel) included in the pixel unit14is driven. In an embodiment, for example, where the area of the pixel unit14corresponds to a small area, distances between the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the pixel unit14are narrow. Therefore, only one central pixel PX22included in each of the plurality of display devices10(1) to10(N) may be partially driven, thereby measuring a driving voltage Vel of the light emitting element EL provided in the central pixel PX22. The driving voltage Vel of the light emitting element EL corresponds to a voltage of the first electrode of the light emitting element EL (i.e., the fourth node N4).

In embodiments shown inFIGS.4to8, it is assumed that the central pixel PX22emits light of one color to measure the driving voltage Vel of the light emitting element EL provided in the pixel PX22corresponding to the central portion of the pixel unit14. When the central pixel PX22emits light of only one color, the pixel unit14may emit light with a high luminance, to compare driving voltages Vel between the plurality of display devices10(1) to10(N).

In embodiments shown inFIGS.4to8, it is assumed that central pixels PX22included in the plurality of display devices10(1) to10(N) emit light of only one color among a first color (red), a second color (blue), and a third color (green), for example. The luminance measurer20may measure a luminance LUM of the central pixel PX22emitting light of only one color, and measure a driving voltage Vel of the light emitting element EL.

FIG.5is a diagram illustrating an embodiment of determining a driving voltage of a light emitting element of each of the plurality of display devices shown inFIG.1.

Referring toFIGS.3to5, in an embodiment, a voltage of the first electrode (or the fourth node N4) of the light emitting element EL (or a driving voltage Vel of the light emitting element EL) provided in each of the plurality of display devices10(1) to10(N) may be measured with a same reference to measure a driving voltage Vel of the central pixel PX22included in each of the plurality of display devices10(1) to10(N).

In an embodiment, for example, the voltage of the first electrode (or the fourth node N4) of the light emitting element EL may be arbitrarily changed. Specifically, when the voltage of the first electrode (or the fourth node N4) of the light emitting element EL is changed from the first driving power voltage ELVDD to the second driving power voltage ELVSS, a driving current IELflowing through the light emitting element EL may decrease (graph {circle around (1)} inFIG.5). In addition, a driving current IELflowing through the first transistor T1may increase (graph {circle around (2)} inFIG.5).

A voltage at which the driving current IELflowing through the light emitting element EL and the driving current IELflowing through the first transistor T1correspond to each other at the same time (or are the same as each other) may be the driving voltage Vel of the light emitting element EL.

In such an embodiment, as described above, the voltage at which the driving current IELflowing through the light emitting element EL provided in each of the plurality of display devices10(1) to10(N) and the driving current IELflowing through the first transistor T1provided in each of the plurality of display devices10(1) to10(N) correspond to each other at the same time may correspond to the driving voltage Vel of the light emitting element EL provided in each of the plurality of display devices10(1) to10(N).

In such an embodiment, a saturation voltage Vsat (seeFIG.6) of the light emitting element EL provided in each of the plurality of display devices10(1) to10(N) as shown inFIG.6may be calculated by considering the driving voltage Vel of the light emitting element EL provided in each of the plurality of display devices10(1) to10(N).

FIG.6is a diagram illustrating an embodiment of calculating a saturation voltage of the light emitting element of each of the plurality of display devices shown inFIG.1.

Referring toFIGS.5and6, a graph illustrated inFIG.6shows change in luminance LUM according to change in second driving power voltage ELVSS to which the driving voltage Vel of the light emitting element EL is reflected. The second driving power voltage ELVSS is a voltage lower by a threshold voltage VthEL of the light emitting element EL than the driving voltage Vel of the light emitting element EL.

Referring toFIG.6, the luminance LUM of an image displayed on the display panel PNL may decrease as the driving voltage Vel of the light emitting element EL increases. That is, referring toFIGS.5and6, the driving voltage Vel of the light emitting element EL and the luminance LUM of an image displayed on the display panel PNL may be changed as the second driving power voltage ELVSS is changed.

Referring toFIGS.3to6, the luminance measurer20may be connected to the first electrode (or the fourth node N4) of the light emitting element EL of the display panel PNL included in each of the plurality of display devices10(1) to10(N), to measure a luminance LUM.

Referring toFIG.6, the luminance measurer20may transmit, to the driving voltage measurer30, data including a luminance LUM corresponding to the second driving power voltage ELVSS changed as shown inFIG.5.

The driving voltage measurer30may measure a variation of the luminance LUM. The driving voltage measurer30may calculate a voltage corresponding to a point at which the variation of the luminance LUM is changed as a saturation voltage Vsat for driving the display panel PNL.

In an embodiment, the luminance of an image displayed on the display panel PNL may be changed as the second driving power voltage ELVSS is changed. The voltage corresponding to the point at which the variation of the luminance LUM is changed may be determined as the saturation voltage Vsat. In an embodiment, for example, when the second driving power voltage ELVSS is changed, the luminance LUM of the image gradually falls with about a first slope {circle around (3)} and then falls with a second slope {circle around (4)} steeper than the first slope {circle around (3)} at a specific time. The driving voltage measurer30may determine, as the saturation voltage Vsat, a voltage corresponding to the point at which the luminance LUM of the image falls with a second slope {circle around (4)} steeper than the first slope {circle around (3)}.

In such an embodiment, the driving voltage measurer30may calculate a saturation voltage Vsat of the display panel PNL included in each of the plurality of display devices10(1) to10(N).

FIG.7is a diagram illustrating an embodiment of calculating a current density and a degradation weight value of each of the plurality of display devices shown inFIG.1.

In an embodiment, the processor40may calculate a current density CDT of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the saturation voltage Vsat calculated by the driving voltage measurer30.

Referring toFIG.7, the current density CDT may increase as the driving voltage Vel of the light emitting element EL increases. The current density CDT according to the driving voltage Vel of the light emitting element EL may be experimentally measured to be pre-stored in the memory400. In an embodiment, the current density CDT may satisfy the following Equation 1.
CDT(current density)=a×Vsat(saturation voltage)+d(here,aanddare constants)  [Equation 1]

In an embodiment, the memory400included in the processor40may pre-store a plurality of parameters (e.g., a and d in Equation 1) for calculating the current density CDT. The calculator401included in the processor40may calculate a current density CDT (e.g., a first current density Vd inFIG.7) of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the saturation voltage Vsat calculated by the driving voltage measurer30and the plurality of parameters (a and d) stored in the memory400.

In an embodiment, although not shown inFIG.7, the processor40may calculate a degradation weight value B of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the calculated current density CDT (or first current density Vd).

In an embodiment, the degradation weight value B may satisfy the following Equation 2.

In Equation 2, S denotes a slope constant, T denotes a time constant, Th denotes a driving time, and Acc denotes an acceleration coefficient. In Equation 2, istd denotes a center value of a luminance LUM of the display panel PNL provided in each of the plurality of display devices10(1) to10(N), i denotes a luminance LUM of a display panel PNL provided in a measurement target display device, Vstd denotes a center value of a current density CDT of the display panels PNL provided in each of the plurality of display devices10(1) to10(N), and V denotes a current density CDT of the display panel PNL provided in a measurement target display device.

In an embodiment, the memory400included in the processor40may pre-store a plurality of parameters S, T, and ACC for calculating the degradation weight value B.

The calculator401included in the processor40may calculate a center value istd of a luminance LUM of the display panel PNL provided in each of the plurality of display devices10(1) to10(N). The center value istd of the luminance LUM corresponds to a median value of different luminances LUM measured in the display panels PNL provided in the plurality of display devices10(1) to10(N).

The calculator401included in the processor40may calculate a center value Vstd of a current density CDT of the display panel PNL provided in each of the plurality of display devices10(1) to10(N). The center value Vstd of the current density CDT corresponds to a median value of different current densities CDT calculated in the display panel PNL provided in each of the plurality of display devices10(1) to10(N).

The calculator401included in the processor40may calculate the degradation weight value B of the display panel PNL provided in the measurement target display device by using the center value istd of the luminance LUM, the center value of the current density CDT, the luminance i of the measurement target display device, the current density CDT of the measurement target display device, and the plurality of parameters S, T, ACC stored in the memory400at the driving time Th.

In an embodiment, as described above, data (or a degradation weight value B) for correcting an afterimage between the plurality of produced display devices10(1) to10(N) may be calculated by measuring the driving voltage Vel (seeFIG.5) of the plurality of display devices10(1) to10(N) in the manufacturing process of the plurality of display devices10(1) to10(N). The processor40may supply the data control signal Dcon including the calculated degradation weight value B of each of the plurality of display devices10(1) to10(N) to a produced measurement target display device, and perform degradation compensation on the plurality of display devices10(1) to10(N), thereby compensating for the afterimage. Accordingly, the plurality of display devices10(1) to10(N) may be manufactured to have uniform quality.

FIG.8is a flowchart illustrating a driving method of the display manufacturing system in accordance with an embodiment of the disclosure.

In an embodiment, a luminance LUM of a display panel PNL may be measured corresponding to the second driving power voltage ELVSS which is changed, and a saturation voltage Vsat may be calculated (S10).

In such an embodiment, the luminance measurer20may measure a luminance LUM of an image output from the pixel PX22located at a central portion of the display panel PNL, corresponding to the second driving power voltage ELVSS which is changed. The driving voltage measurer30may calculate a saturation voltage Vsat by measuring a variation of the luminance LUM. Only the pixel PX22located at the central portion of the display panel PNL is driven, and the other pixels PX11, PX21, PX31, PX12, PX32, PX13, PX23, and PX33are not driven. Also, the pixel PX22located at the central portion of the display panel PNL emits light of only one color.

In an embodiment, the processor40may calculate a current density CDT of each of the plurality of display devices10(1) to10(N), based on the calculated saturation voltage Vsat (S11).

In such an embodiment, the calculator401included in the processor40may calculate a current density CDT of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the saturation voltage Vsat of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) and a plurality of parameter a and d stored in the memory400.

In an embodiment, the processor40may calculate a degradation weight value B of each of the plurality of display devices10(1) to10(N) by using the calculated current density CDT (S12).

In such an embodiment, the processor40may calculate a degradation weight value B of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the current density of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) and a plurality of parameters S, T, and ACC stored in the memory400.

In an embodiment, the processor40may drive a measurement target display panel by reflecting the degradation weight value B (S13).

In such an embodiment, the processor40may calculate data (or a degradation weight value B) for correcting an afterimage between the plurality of produced display devices10(1) to10(N) by measuring the driving voltage Vel (seeFIG.5) of the plurality of display devices10(1) to10(N) in the manufacturing process of the plurality of display devices10(1) to10(N). The processor40may supply, to a measurement target display device, a data control signal Dcon including the calculated degradation weight value B of each of the plurality of display devices10(1) to10(N), and perform degradation compensation on the plurality of display devices10(1) to10(N), thereby compensating for the afterimage.

FIG.9is a diagram illustrating an alternative embodiment of calculating a degradation weight value of each of the plurality of display devices shown inFIG.1.

Referring toFIG.9, the pixel unit14may include a plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33. Although an embodiment where the pixel unit14includes 9 pixels is illustrated inFIG.4, the disclosure is not limited thereto.

In a manufacturing process of a plurality of display devices10(1) to10(N), when the area of a display panel PNL of each of the plurality of produced display devices10(1) to10(N) is a large area, degradation weight values B may be different from each other even between pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in one pixel unit14.

In such an embodiment, a degradation weight value B of a display panel PNL provided in each of the plurality of display devices10(1) to10(N) may be calculated by driving all the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in each of the plurality of display devices10(1) to10(N).

In such an embodiment, it is assumed that the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33are all driven to calculate each of the degradation weight values B between the pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in one pixel unit14.

In such an embodiment, it is assumed that the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the pixel unit14emit light of one color. In such an embodiment, it is assumed that the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the plurality of display devices10(1) to10(N) emit light of only one color among a first color (red), a second color (blue), and a third color (green), for example. In such an embodiment, the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the plurality of display devices10(1) to10(N) are substantially the same as those described above with reference toFIG.4, and any repetitive detailed description thereof will be omitted.

Referring toFIGS.3and9, the luminance measurer20may be connected to the first electrode (or the fourth node N4) of the light emitting element EL provided in the pixel PX22located at a central portion of the display panel PNL of each of the plurality of display devices10(1) to10(N) produced in a display manufacturing process, to measure a driving current IEL flowing through the light emitting element EL as the second driving power voltage ELVSS is changed.

The driving voltage measurer30may measure a variation of a luminance LUM of the pixel PX22located at the central portion of the display panel PNL, and calculate a voltage corresponding to a point at which the variation of the luminance LUM is changed as a saturation voltage Vsat for driving the display panel PNL. Such an operation of the driving voltage measure30is substantially the same as that described above with reference toFIG.6, and any repetitive detailed description thereof will be omitted.

The processor40may calculate a current density CDT of each of the plurality of produced display devices10(1) to10(N) by using the saturation voltage Vsat calculated by the driving voltage measurer30.

in such an embodiment, the processor40may calculate a current density CDT of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the pixel PX22located at the central portion of the display panel PNL provided in each of the plurality of display devices10(1) to10(N).

In such an embodiment, the processor40may calculate a degradation weight value B of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the calculated current density CDT.

In an embodiment, the degradation weight B may satisfy the following Equation 3.

In Equation 3, S denotes a slope constant, T denotes a time constant, Th denotes a driving time, and Acc denotes an acceleration coefficient. In Equation 3, istd denotes a center value of a luminance LUM of each of the plurality of display devices10(1) to10(N), i denotes a luminance LUM of a display panel PNL provided in a measurement target display device, Vstd denotes a center value of a current density CDT of each of the plurality of display devices10(1) to10(N), V denotes a current density CDT of the display panel PNL provided in a measurement target display device, and L denotes a compensation parameter for each pixel position.

The calculator401included in the processor40may calculate a compensation parameter L for each pixel position of the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the pixel unit14.

In such an embodiment, the compensation parameter L for each position of the pixel PX11may be calculated as a value of a current density CDT of the pixel PX11over a current density CDT of the pixel PX22, that is, a ratio of the current density CDT of the pixel PX11with respect to the current density CDT of the pixel PX22. The compensation parameter L for each position of the pixel PX21may be calculated as a value of a current density CDT of the pixel PX21over the current density CDT of the pixel PX22. The compensation parameter L for each position of the pixel PX31may be calculated as a value of a current density CDT of the pixel PX31over the current density CDT of the pixel PX22. The compensation parameter L for each position of the pixel PX12may be calculated as a value of a current density CDT of the pixel PX12over the current density CDT of the pixel PX22. The compensation parameter L for each position of the pixel PX32may be calculated as a value of a current density CDT of the pixel PX32over the current density CDT of the pixel PX22. The compensation parameter L for each position of the pixel PX13may be calculated as a value of a current density CDT of the pixel PX13over the current density CDT of the pixel PX22. The compensation parameter L for each position of the pixel PX23may be calculated as a value of a current density CDT of the pixel PX23over the current density CDT of the pixel PX22. The compensation parameter L for each position of the pixel PX33may be calculated as a value of a current density CDT of the pixel PX33over the current density CDT of the pixel PX22.

In such an embodiment, as described above, degradation compensation for each position of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33in one display device may be performed by considering the compensation parameter L for each position of the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33in the pixel unit14when the degradation weight value B is calculated. Accordingly, when the display device has a large area, the plurality of display devices10(1) to10(N) may be manufactured to have uniform lifetime by performing degradation compensation.

FIG.10is a flowchart illustrating a driving method of the display manufacturing system in accordance with an alternative embodiment of the disclosure.

In an embodiment, a luminance LUM of a display panel PNL may be measured, and a saturation voltage Vsat may be calculated (S20).

In such an embodiment, the luminance measurer20may measure a luminance LUM of an image output from the pixel PX22located at a central portion of the display panel PNL, corresponding to the second driving power voltage ELVSS. The driving voltage measurer30may calculate a saturation voltage Vsat by measuring a venation of the luminance LUM. A plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the display panel PNL are all driven. Also, the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the display panel PNL emit light only one color.

In an embodiment, the processor40may calculate a current density CDT of each of the plurality of display devices10(1) to10(N), based on the calculated saturation voltage Vsat (S21).

In such an embodiment, the calculator401included in the processor40may calculate a current density CDT of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) by using the saturation voltage Vsat of the display panel PNL provided in each of the plurality of display devices10(1) to10(N) and a plurality of parameter a and d stored in the memory400.

In an embodiment, the processor40may calculate a compensation parameter L for each position of pixels PXij included in the display panel PNL (S22).

In such an embodiment, the calculator401included in the processor40may calculate a compensation parameter L for each position of each of the plurality of pixels PX11, PX21, PX31, PX12, PX22, PX32, PX13, PX23, and PX33included in the display panel PNL, based on the current density CDT of the pixel PX22located at a central portion of the display panel PNL.

In an embodiment, the processor40may calculate a degradation weight value B of the display panel PNL of each of the plurality of display devices10(1) to10(N) by using the compensation parameter L for each position and the current density CDT (S23).

In such an embodiment, the processor40may calculate a degradation weight value B of the display panel PNL of each of the plurality of display devices10(1) to10(N) by using the current density CDT of the display panel PNL of each of the plurality of display devices10(1) to10(N), the compensation parameter L for each position, and a plurality of parameter S, T, and ACC stored in the memory400.

In an embodiment, the processor40may drive a measurement target display panel by reflecting the degradation weight value B (S24).

In such an embodiment, the processor40may drive the display panel PNL by supplying a data control signal Dcon including the degradation weight value B to the measurement target display device.

In embodiments of the display manufacturing system and the driving method of the display manufacturing system in accordance with the disclosure, a lifetime characteristic of display devices can be predicted through measurement of a driving power voltage in a process of manufacturing the display devices.

In embodiments of the display manufacturing system and the driving method of the display manufacturing system in accordance with the disclosure, the lifetime of display devices can be controlled to be constant by using a lifetime distribution of the display devices.

In embodiments of the display manufacturing system and the driving method of the display manufacturing system in accordance with the disclosure, a lifetime distribution is predicted and compensated in a process of manufacturing display devices, thereby reducing manufacturing time and improving productivity.