KR102592070B1 - Sensor package module and organic light emitting display having the same - Google Patents

Abstract

According to this embodiment, a display panel including a plurality of subpixels, a gate driver supplying a gate signal to the display panel, a data driver supplying a data signal to the display panel, and supplying first power and second power to the display panel. a power supply unit, and a voltage control unit generating a voltage change signal in response to deterioration information of at least one subpixel among a plurality of subpixels, wherein the power supply unit supplies at least one of a first power source and a second power source in response to the voltage change signal. An organic light emitting display device that changes the voltage level of a power source and a method of driving the same can be provided.

Description

Organic light emitting display device and driving method thereof {SENSOR PACKAGE MODULE AND ORGANIC LIGHT EMITTING DISPLAY HAVING THE SAME}

These embodiments relate to an organic light emitting display device and a method of driving the same.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, including liquid crystal display devices (LCDs), plasma display devices, and organic light emitting display devices ( Several types of flat panel displays such as OLED (Organic Light Emitting Display Device) have appeared.

Organic light emitting display devices display images using organic light emitting diodes, which are self-luminous devices, so they are easy to slim and have excellent viewing angles and contrast ratios.

However, organic light emitting diodes used in organic light emitting display devices have problems in that they deteriorate over time, causing afterimages and deteriorating image quality. Therefore, compensation for deterioration must be provided.

The purpose of the present embodiments is to provide an organic light emitting display device and a method of driving the same that can compensate for degradation.

Additionally, another purpose of the present embodiments is to provide an organic light emitting display device and a method of driving the same that can prevent an increase in power consumption.

In one aspect, the present embodiments include a display panel including a plurality of subpixels, a gate driver supplying a gate signal to the display panel, a data driver supplying a data signal to the display panel, and a first power source and a second power supply to the display panel. It includes a power supply unit that supplies a voltage control unit that generates a voltage change signal in response to deterioration information of at least one subpixel among the plurality of subpixels, and the power supply unit provides one of the first power source and the second power source in response to the voltage change signal. An organic light emitting display device that changes the voltage level of at least one power source is provided.

In another aspect, the present embodiments provide a method of driving an organic light emitting display device including a display panel having a plurality of subpixels, including generating deterioration information of the organic light emitting diode at a preset point in time, A method of driving an organic light emitting display device is provided, including the step of changing the voltage level of at least one of the first power source and the second power supply correspondingly.

According to embodiments of the present invention, an organic light emitting display device capable of compensating for degradation and a driving method thereof can be provided.

According to embodiments of the present invention, an organic light emitting display device and a driving method thereof that can prevent an increase in power consumption can be provided.

1 is a structural diagram showing an organic light emitting display device according to embodiments of the present invention.
FIG. 2 is a circuit diagram showing an embodiment of the subpixel shown in FIG. 1.
FIG. 3 is a graph showing the characteristics of the first transistor shown in FIG. 2.
Figure 4 is a graph showing the change in the driving current flowing through the organic light emitting diode due to deterioration when the difference between the gate electrode and the source electrode of the first transistor is constant and the resistance characteristics of the first transistor according to the change in the first power source.
FIG. 5 is a conceptual diagram showing two subpixels connected to one first power line in the display panel shown in FIG. 1.
FIG. 6 is a timing diagram showing the driving process of the organic light emitting display device shown in FIG. 1.
FIG. 7 is a timing diagram showing the process of driving the subpixel shown in FIG. 2 in a display section.
FIG. 8 is a timing diagram showing the process of compensating the threshold voltage in the subpixel shown in FIG. 2.
FIG. 9 is a structural diagram showing an embodiment of the timing controller shown in FIG. 1.
FIG. 10 is a structural diagram showing an embodiment of the data driver shown in FIG. 1.
FIG. 11 is a structural diagram showing an embodiment of the power supply unit shown in FIG. 1.
Figure 12 is a flowchart showing a method of driving an organic light emitting display device according to embodiments of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary drawings. In adding reference numerals to components in each drawing, identical components may have the same reference numerals as much as possible even if they are shown in different drawings. In describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

Additionally, when describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the components are not limited by the term. When a component is described as being “connected,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there are no other components between each component. It should be understood that may be “interposed” or that each component may be “connected,” “combined,” or “connected” through other components.

1 is a structural diagram showing an organic light emitting display device according to embodiments of the present invention.

Referring to FIG. 1 , the organic light emitting display device 100 may include a display panel 110, a data driver 120, a gate driver 130, a timing controller 140, and a power supply unit 150.

The display panel 110 may be arranged so that a plurality of gate lines (GL1,...,GLn) and a plurality of data lines (DL1,...,DLm) intersect. Additionally, it may include a plurality of subpixels 101 formed corresponding to an area where a plurality of gate lines (GL1,...,GLn) and a plurality of data lines (DL1,...,DLm) intersect. The plurality of subpixels 101 may include organic light emitting diodes (not shown) and a pixel circuit (not shown) that supplies driving current to the organic light emitting diodes. The pixel circuit can be connected to the gate lines (GL1,...,GLn) and data lines (DL1,...,DLm) to supply driving current to the organic light emitting diode. Here, the wiring disposed on the display panel 110 is not limited to a plurality of gate lines (GL1,...,GLn) and a plurality of data lines (DL1,...,DLm). The display panel 110 can operate by receiving first power (EVDD) and second power (EVSS).

The data driver 120 may apply data signals to a plurality of data lines DL1,...,DLm. The data signal may correspond to a gray level, and the voltage level of the data signal may be determined according to the corresponding gray level. The voltage of the data signal may be referred to as data voltage. Additionally, the data driver 120 can sense deterioration information from the subpixel 101. The information that the data driver 120 senses from the subpixel 101 is not limited to this.

Here, the number of data drivers 120 is shown as one, but it is not limited to this and may be two or more depending on the size and resolution of the display panel 110. Additionally, the data driver 120 may be implemented as an integrated circuit.

The gate driver 130 may apply a gate signal to a plurality of gate lines (GL1,...,GLn). The subpixels 101 corresponding to the plurality of gate lines GL1,...,GLn to which the gate signal is applied can receive the data signal. Additionally, the gate driver 130 can transmit a sensing signal to the subpixel 101. The subpixel 101 that receives the sensing signal output from the gate driver 130 can receive the sensing voltage output from the data driver 120. Here, the number of gate drivers 130 is shown as one, but is not limited thereto and may be at least two. In addition, the gate drivers 130 are disposed on both sides of the display panel 110, one gate driver 130 is connected to the odd gate line among the plurality of gate lines GL1,...,GLn, and the other gate driver 130 is connected to the odd gate line among the plurality of gate lines GL1,...,GLn. (130) may be connected to an even-numbered gate line among the plurality of gate lines (GL1,...,GLn). However, it is not limited to this. The gate driver 130 may be implemented as an integrated circuit.

The timing controller 140 can control the data driver 120 and the gate driver 130. Additionally, the timing controller 140 can transmit image data corresponding to the data signal to the data driver 120. Image data may be a digital signal. The timing controller 140 can correct the video signal and transmit it to the data driver 120. The operation of the timing controller 140 is not limited to this. The timing controller 140 may be implemented as an integrated circuit.

The power unit 150 can receive AC power, rectify it into DC power, and supply the rectified DC power to the display panel 110. The power unit 150 can generate a plurality of DC powers with different voltage levels using rectified DC power and supply them to the data driver 120, gate driver 130, and timing controller 140. Additionally, the power supply unit 150 can increase the voltage level of the DC power supplied in response to the deterioration of the organic light emitting diode of the display panel 110. However, it is not limited to this.

FIG. 2 is a circuit diagram showing an embodiment of the subpixel shown in FIG. 1.

Referring to FIG. 2, the subpixel 101 may include an organic light emitting diode (OLED) and a pixel circuit that drives the organic light emitting diode (OLED). The pixel circuit may include a first transistor (M1), a second transistor (M2), a third transistor (M3), and a capacitor (Cst).

The first transistor (M1) has a first electrode connected to the first power line (VL1) through which the first power (EVDD) is transmitted, a gate electrode connected to the first node (N1), and a second node (N2). Two electrodes can be connected. The first transistor M1 may cause current to flow to the second node N2 in response to the voltage delivered to the first node N1. The first electrode of the first transistor M1 may be a drain electrode, and the second electrode may be a source electrode. However, it is not limited to this.

The current flowing to the second node (N2) may correspond to Equation 1 below.

Here, Id means the amount of current flowing in the second node (N2), k means the electron mobility of the transistor, and Vgs means the voltage difference between the gate electrode and the source electrode of the first transistor (M1). , Vth means the threshold voltage of the first transistor (M1).

Therefore, since the amount of current varies depending on the deviation between electron mobility and threshold voltage, deterioration of image quality can be prevented by correcting the data signal in response to the deviation between electron mobility and threshold voltage. Additionally, electron mobility may vary depending on temperature. The first transistor (M1) may be referred to as a driving transistor.

The second transistor M2 may have a first electrode connected to the data line DL, a gate electrode connected to the gate line GL, and a second electrode connected to the first node N1. Accordingly, the second transistor M2 can transmit the data voltage Vdata corresponding to the data signal to the first node N1 in response to the gate signal transmitted through the gate line GL. The first electrode of the second transistor M2 may be a drain electrode, and the second electrode may be a source electrode. However, it is not limited to this.

The third transistor M3 may have a first electrode connected to the second node N2, a gate electrode connected to the sensing control line Sense, and a second electrode connected to the second power line VL2. The third transistor (M3) can transmit the voltage of the second node (N2) to the second power line (VL2) in response to the sensing control signal transmitted through the sensing control line (Sense). The first electrode of the third transistor M3 may be a drain electrode, and the second electrode may be a source electrode. However, it is not limited to this.

The first electrode of the capacitor Cst may be connected to the first node N1 and the second electrode may be connected to the second node N2. The capacitor Cst can keep the voltage of the gate electrode and the source electrode of the first transistor M1 constant.

The organic light emitting diode (OLED) may have an anode connected to a second node (N2) and a cathode electrode connected to a second power source (EVSS). Here, the second power source (EVSS) may be ground. However, it is not limited to this. The second power source (EVSS) can be supplied through a low power line. Organic light-emitting diodes (OLEDs) can emit light in response to the amount of current when current flows from the anode electrode to the cathode electrode. Organic light-emitting diodes (OLEDs) can emit any one color among red, green, blue, and white. However, it is not limited to this.

The circuit of the subpixel 101 employed in the organic light emitting display device 100 is not limited to this.

In the subpixel 101 implemented as described above, information about the deterioration of the organic light emitting diode (OLED) and the threshold voltage of the first transistor (M1) can be calculated using the voltage of the second node (N2). That is, when the third transistor (M3) is turned on in response to the sensing control signal, the voltage of the second node (N2) can be transmitted to the second power line (VL2). The operation of the third transistor (M3) is not limited to this, and the second node (N2) is initialized by transmitting the initialization voltage transmitted to the second power line (VL2) to the second node (N2) in response to the sensing control signal. can do.

Additionally, the subpixel 101 may be connected to a first switch (Spre), a second switch (Rpre), and a third switch (Sam). The first switch (Spre) is connected between the second power line (VL2) and the first reset voltage (VPRES), and the second switch (Rpre) is connected between the second power line (VL2) and the second reset voltage (VPRER). can be connected Additionally, the third switch (SAM) may be connected between the second power line (VL2) and the data driver 120. The first reset voltage (VPRES) is the voltage delivered to the second node (N2) in the process of sensing the voltage of the second node (N2), and the second reset voltage (VPRER) transfers the driving current to the organic light emitting diode (OLED). This may be the voltage delivered to the second node (N2) in the process. However, it is not limited to this.

FIG. 3 is a graph showing the characteristics of the first transistor shown in FIG. 2.

Referring to FIG. 3, the horizontal axis represents the voltage magnitude of Vds corresponding to the voltage difference between the first and second electrodes of the first transistor (M1), and the vertical axis represents the voltage magnitude of Vds from the first electrode to the second electrode of the first transistor (M1). Indicates the amount of driving current flowing to the electrode. And, on the graph, the first transistor (M1) can operate divided into a linear region (LA) and a saturation region (SA). The driving current of the first transistor M1 increases as Vds increases in the linear region (LA), and in the saturation region (SA), the increase in driving current increases slightly even as Vds increases. Also, the magnitude of the current may vary in response to the gate voltage applied to the gate electrode of the first transistor (M1). That is, as shown, each curve can be distinguished according to the level of the gate voltage, and the larger the gate voltage, the larger the driving current can be. Since the organic light emitting diode (OLED) emits light in response to the flow of current, the first transistor (M1) is operated in the saturation region (SA) to ensure that a constant current is supplied to the organic light emitting diode (OLED).

However, since the saturation area (SA) has a higher voltage than the linear area (LA), a problem of increased power consumption occurs when the first transistor (M1) operates in the saturation area (SA). Therefore, in order to reduce power consumption, it is advantageous to operate the first transistor M1 in the saturation area SA, but close to the linear area LA.

Figure 4 is a graph showing the change in the driving current flowing through the organic light emitting diode due to deterioration when the difference between the gate electrode and the source electrode of the first transistor is constant and the resistance characteristics of the first transistor according to the change in the first power source.

Referring to FIG. 4, the horizontal axis represents voltage, and the vertical axis represents the size of the driving current (IOLED) supplied to the organic light emitting diode (OLED). In addition, curve a represents the size of the driving current (IOLED) flowing in response to the voltage levels of the first power supply (EVDD) and the second power supply (EVSS), and curve b represents the size of the first transistor according to the voltage level of the first power supply (EVDD). It shows the resistance characteristics of .

Before deterioration of the organic light emitting diode (OLED) occurs, the first transistor M1 can ensure that curve b meets the saturation region, which is the point where the slope of curve a is 0. However, when the organic light emitting diode (OLED) deteriorates, the curve changes from curve a to curve a' and the slope decreases, showing that the first transistor M1 operates in the linear region of curve b. As the degree of deterioration increases, the slope of curve a' becomes lower. Therefore, as shown in FIG. 3, when operated close to the non-linear region, the organic light emitting diode (OLED) may operate in the linear region due to deterioration. Therefore, the amount of driving current (IOLED) flowing through the organic light emitting diode (OLED) can easily change due to deterioration. However, if the voltage level of the first power supply (EVDD) is increased in response to deterioration, the first transistor (M1) can operate in the saturation region of curve b', thereby reducing the driving current (IOLED) flowing through the organic light emitting diode (OLED). The change in quantity is not large.

For the same reason as above, in order to reduce power consumption, the first transistor (M1) is operated close to the linear region, but if the voltage level of the first power supply (EVDD) is increased in response to deterioration, the size becomes constant as shown in curve b'. As the maintenance period becomes longer, it may operate in the saturation region. Therefore, even if the organic light emitting diode (OLED) deteriorates, there may not be a significant change in the amount of current flowing through the organic light emitting diode (OLED).

And, the voltage of the first power supply (EVDD) can be set in accordance with Equations 2 and 3 below.

Here, EVDD is the voltage level of the first power supply (EVDD), Vd is the voltage of the first electrode of the first transistor (M1), Voled is the voltage applied to the organic light emitting diode (OLED), and Vds is the voltage of the first transistor (M1). is the voltage difference between the first and second electrodes, Vgs is the voltage difference between the gate electrode and the second electrode of the first transistor (M1), and Vth is the threshold voltage of the first transistor (M1).

The voltage level of the voltage of the first power source (EVDD) can be set to be equal to or greater than the voltage of the first electrode of the first transistor (M1) and the voltage applied when the driving current flows to the organic light emitting diode (OLED). To minimize power, it can be determined as in Equation 2 above. And, the voltage difference between the first electrode and the second electrode of the first transistor (M1), the voltage difference between the gate electrode and the second electrode of the first transistor (M1), and the threshold voltage (Vth) of the first transistor (M1) ) Determine the voltage of the first electrode of the first transistor (M1) through Equation 3 above, and determine the voltage of the first electrode of the first transistor (M1) in accordance with Equation 2 above. The voltage of the first power supply (EVDD) can be set. And, setting the voltage of the first power supply (EVDD) is explained using the subpixel shown in FIG. 2 as an example. The data voltage (Vdata) delivered to the first node (N1) of the subpixel is 7.6V, the voltage applied to the organic light emitting diode (OLED) in response to the flow of the driving current (IOLED) is 14.8V, and the first transistor Assuming that the threshold voltage of (M1) is 2.4V and applying Equation 3 above, the voltage of the first electrode of the first transistor (M1) becomes 5.2V as shown in Equation 4 below.

Additionally, the result of Equation 4 and the voltage of the organic light emitting diode (OLED) correspond to Equation 1 above, and the voltage of the first power source (EVDD) may be 20V. In this case, 20V corresponds to the voltage level of the first power supply (EVDD) that can enable the first transistor (M1) to operate in the saturation region with minimum power consumption. When deterioration occurs, the efficiency of the organic light-emitting diode (OLED) decreases, so the voltage applied to the organic light-emitting diode (OLED) must be increased in order for the organic light-emitting diode (OLED) to show the same luminance. Therefore, the voltage level of the first power supply (EVDD) must be set to increase in response to deterioration. However, the voltage level of the first power source (EVDD) must satisfy Equation 2 above even if the organic light emitting diode (OLED) deteriorates. Here, the data voltage (Vdata) and the voltage applied to the organic light emitting diode (OLED) are illustrative and are not limited thereto. In addition, organic light-emitting diodes (OLEDs) emit one of red, green, blue, and white light. When emitting white light, the voltage applied to the organic light-emitting diodes (OLEDs) is 3mA when the driving current is 3mA. It is about 14.8V and can be lower than this if it displays red, green, or blue light.

FIG. 5 is a conceptual diagram showing two subpixels connected to one first power line in the display panel shown in FIG. 1.

Referring to FIG. 5, the first subpixel 101a and the second subpixel 101b may be connected to the first power line VL1. The first subpixel 101a refers to a subpixel arranged at the first distance D1 from the side 110a to which the first power (EVDD) is supplied from the display panel 110, and the second subpixel 101b means a subpixel arranged on one side (110a) to which the first power (EVDD) is supplied in the display panel 110 and at the second distance (D2). The first distance D1 is shorter than the second distance D2. The first subpixel 101a and the second subpixel 101b may be connected to the same first power line VL1. A plurality of subpixels are connected to the first power line VL1 between the first subpixel 101a and the second subpixel 101b, but are omitted here for convenience of explanation. The first subpixel 101a may refer to the subpixel located closest to one side 110a of the display panel 110, and the second subpixel 101b may refer to the subpixel disposed closest to one side 110a of the display panel 110. ) may refer to the subpixel furthest from the side 110a. However, it is not limited to this. One side 110a of the display panel 110 may be a portion to which the first power EVDD is supplied.

Since the first power line (VL1) has line resistance, a voltage drop occurs in the first voltage (EVDD) transmitted through the first power line (VL1). Even if a certain amount of first power (EVDD) is supplied to the first power line (VL1) due to the voltage drop in the first power line (VL1), the first power (EVDD) input to the first subpixel (101a) The voltage level becomes higher than the voltage level of the first power source (EVDD) input to the second subpixel (101b).

For the above reason, since the first power source (EVDD) is supplied from one side (110a) of the display panel 110 through a plurality of first power lines (VL1), the first power source (EVDD) of the display panel 110 is The voltage level of the first power source EVDD can be determined based on at least one subpixel located at a predetermined distance from the supplied side 110a. The subpixel located at a predetermined distance may be a subpixel located furthest from one side 110a of the display panel 110 to which the first power EVDD is supplied. However, it is not limited to this.

FIG. 6 is a timing diagram showing the driving process of the organic light emitting display device shown in FIG. 1.

Referring to FIG. 6, driving of the organic light emitting display device 100 can be divided into a loading period (TL), a driving period (TD), and an off period (Toff). During the loading period (TL), the organic light emitting display device 100 can be prepared for operation when the user turns on the organic light emitting display device 100. The driving period (TD) is a period in which the organic light emitting display device 100 receives an image signal from a set (not shown) and displays an image, and the off period (Toff) is a period when the organic light emitting display device 100 stops operating. This section can correspond to a state in which the user turns off the electronic device employing the organic light emitting display device 100. Electron mobility can be sensed in the driving period (TD).

In the off period (Toff), deterioration compensation can be performed by receiving information about deterioration from the subpixel. The off period (Toff) may include a first sensing period (Ts1) and a second sensing period (Ts2).

In the second sensing period (Ts2), information about the voltage level of the first power source (EVDD) can be changed. That is, if the information about the voltage level is changed in the second sensing period (Ts2), the voltage level of the first power supply (EVDD) in the driving period (TD) is changed to the first power supply (EVDD) changed in the second sensing period (Ts2). The voltage level of the first power supply (EVDD) can be changed and applied in response to the information about the voltage level. However, it is not limited to this and it is also possible to change the voltage level of the second power supply (EVSS). In the second sensing period (Ts2), deterioration information can be sensed by sensing the voltage of the second node (N2) of FIG. 2. At this time, since the voltage of the second node (N2) is stored in response to the threshold voltage, if the voltage of the second node (N2) is sensed while the threshold voltage is not compensated, accurate degradation information cannot be sensed. Therefore, in the off period (Toff), a first sensing period (Ts1) to compensate for the threshold voltage is first performed, and then a second sensing period (Ts2) is performed to sense deterioration information. However, it is not limited to this, and in the case where the threshold voltage is compensated by storing the gate voltage in the storage capacitor (Cst) rather than changing the voltage of the data signal in response to the threshold voltage, the threshold voltage is compensated in the off period (Toff). It is also possible to perform only deterioration compensation since there is no need to do so.

Referring to FIG. 7, the operation of supplying driving current to an organic light emitting diode (OLED) in a pixel circuit will be described. The section supplying the driving current may correspond to the display section in FIG. 6.

The second node (N2) can be initialized by turning on the first switch (RPRE) and turning on the third transistor (M3) by the sensing control signal (Ssen). Also, the first switch (RPRE) and the third transistor (M3) can be turned off. When the second transistor M2 is turned on by the gate signal GATE, the data voltage Vdata may be transmitted to the first node N1. The first transistor M1 may cause a driving current to flow to the second node N2 in response to the voltage between the first node N2 and the second node N2. Accordingly, the driving current may flow in response to the data voltage (Vdata).

And, using FIG. 8, the operation of sensing the threshold voltage in the pixel circuit can be explained. The section for sensing the threshold voltage may correspond to the first sensing period (Ts1) of FIG. 6.

First, while a preset voltage is applied to the data line DL, the gate signal GATE is transmitted and the second transistor M2 can be turned on. When the second transistor M2 is turned on, the voltage applied to the data line DL may be supplied to the first node N1. And, in response to the data voltage applied to the first node (N1), current flows to the second node (N2) by the first transistor (M1), thereby increasing the voltage level of the second node (N2).

And, the first switch (SPRE) may be turned on. When the second switch (SPRE) is turned on, the second initialization voltage (VpreS) may be transmitted to the second power line (VL2). After the first switch (SPRE) is turned on, when the sensing control signal is supplied through the sensing control signal line (Sense), the third transistor (M3) may be turned on. After the third transistor M3 is turned on, the first switch SPRE may be turned off. When the third transistor (M3) is turned on while the first switch (SPRE) is turned off, the voltage of the second node (N2) increases and a certain period of time elapses after the voltage of the second node (N2) begins to rise. When elapsed, the second switch (SAM) can be turned on. When the second switch (SAM) is turned on, the voltage (VN2) of the second node (N2) may be transmitted to the analog-to-digital converter (120b). The second switch (SAM) may be turned on when the voltage of the second node (N2) no longer increases. At this time, the threshold voltage of the first transistor (M1) can be sensed by comparing the voltage sensed by the analog-to-digital converter (120b) with a preset voltage.

As described above, the first initialization voltage (VpreR) is transmitted to the subpixel through the second power line (VL2) in the process of generating a driving current.

FIG. 9 is a structural diagram showing an embodiment of the timing controller shown in FIG. 1.

Referring to FIG. 9, the timing controller 140 may include an arithmetic unit 140a, a voltage control unit 140b, a counter 140c, and a memory 140d.

The calculation unit 140a may receive an image signal (RGB) and generate a corrected image signal (cRGB). The corrected image signal (cRGB) may be an image signal corrected in response to the threshold voltage of the first transistor (M1). However, it is not limited to this. Additionally, the calculation unit 140a can receive a digital sensing signal (Dsense). The digital sensing signal (Dsense) may be supplied as a digital signal of the voltage level of the second node (N2) shown in FIG. 2. The calculation unit 140a may correct the image signal (RGB) using the digital sensing signal (Dsense) and generate a corrected image signal (cRGB). However, generating the corrected image signal (cRGB) in the calculation unit 140a is not limited to this.

The voltage control unit 140b may receive deterioration information and output a voltage change signal (Vcon). Deterioration information may be included in a digital sensing signal (Dsense). The voltage change signal Vcon may be output at a preset first time point. Here, the preset first viewpoint may be the second sensing section shown in FIG. 8. Additionally, the preset first time point may be a time point when the organic light emitting display device 100 is turned off, but is not limited thereto. Additionally, the voltage change signal Vcon may not be output every time the organic light emitting display device 100 is turned off.

Here, the calculation unit 140a and the voltage control unit 140b are shown as separate components, but are not limited thereto and may be one component within the timing controller 140. Additionally, the calculation unit 140a and the voltage control unit 140b are not physically formed within the timing controller 140, but may be implemented through a program.

The counter 140c can count the time for which the display panel 110 maintains the on time. When the time counted by the counter 140c reaches the preset first time, information about reaching the first time can be transmitted to the voltage control unit 140b, and the voltage control unit 140b can output a voltage change signal. . The counter 140c can receive an on-signal, recognize the start of the time to maintain the on-time, and count the time. Because of this, even if deterioration information of the organic light emitting diode (OLED) is not received, the voltage control unit 140b can change the voltage level of the first power source (EVDD) in response to the usage time of the organic light emitting diode (OLED) display 100.

The memory 140d may store the amount of change in the voltage level of the first power source (EVDD) corresponding to the deterioration information. Additionally, the memory 140d may store the amount of change in the voltage level of the first power source (EVDD) corresponding to the first time. The memory 140d may provide information about the amount of change in the voltage level of the first power source EVDD to the voltage control unit 140b so that the voltage control unit 140b outputs a voltage change signal Vcon. Information stored in the memory 140d is not limited to this.

FIG. 10 is a structural diagram showing an embodiment of the data driver shown in FIG. 1.

Referring to FIG. 10, the data driver 120 may include an analog-to-digital converter 120a and a digital-to-analog converter 120b. The analog-to-digital converter 120a may be connected to the second power line VL2, and the digital-to-analog converter 120b may be connected to the data line DL. The analog-to-digital converter 120a and the digital-to-analog converter 120b may be connected to one second power line (VL2) and one data line (DL), respectively. However, it is not limited to this.

The analog-to-digital converter 120a can convert the voltage (VOLED) of the organic light-emitting diode transmitted from the second power line (VL2) into a digital sensing signal (Dsense). The digital sensing signal (Dsense) may include information about the deterioration of the organic light emitting diode.

The digital-to-analog converter 120b can receive image data (RGB) from the timing controller 140. Additionally, the digital-to-analog converter 120b may receive black data (Vblack) and compensation voltage information (Vs_data) corresponding to the compensation voltage (VS) from the timing controller 140. The digital-to-analog converter 120b can generate a data signal, a black data signal, and a compensation voltage and supply them to the data line DL.

FIG. 11 is a structural diagram showing an embodiment of the power supply unit shown in FIG. 1.

Referring to FIG. 11, the power supply unit 150 may include a transformer 150a and a rectifier 150b.

The transformer 150a can receive the first alternating current voltage (Vac1) and change it into a second alternating current voltage (Vac2) having a different voltage level. The transformer 150a may include a first winding (L1) that receives the first AC voltage (Vac1) and a second winding (L2) that outputs the second AC voltage (Vac2). The voltage level of the second AC voltage Vac2 may be determined in accordance with the turns ratio of the first winding L1 and the second winding L2. The winding ratio of the transformer 150a may be changed in response to the voltage change signal Vcon transmitted from the voltage control unit 140b shown in FIG. 8. Accordingly, the transformer 150a changes the voltage level of the second alternating current voltage (Vac2) in response to the voltage change signal (Vcon) output in response to the deterioration of the organic light emitting diode (OLED) to generate direct current output from the power supply unit 150. You can change the voltage level of the power supply. Accordingly, the voltage level of the first power supply (EVDD) can be changed. However, it is not limited to this and the voltage level of the second power supply (EVSS) can be changed.

Figure 12 is a flowchart showing a method of driving an organic light emitting display device according to embodiments of the present invention.

Referring to FIG. 12 , the organic light emitting display device stops operating (S1200). Stopping the driving of the organic light emitting display device may be done by a user to stop using it. When the organic light emitting display device stops operating, it may not display images. The time when the organic light emitting display device was operated can be identified and stored. The organic light emitting display device can operate by receiving first power and second power while being driven. Additionally, the organic light emitting display device includes a plurality of subpixels, and each subpixel may include a first transistor and an organic light emitting diode. The first transistor may supply a driving current to the organic light emitting diode by allowing a driving current to flow from the first electrode to the second electrode in response to the gate voltage applied to the gate electrode. The first transistor must operate in the saturation region to allow a uniform current to flow through the organic light emitting diode. However, to lower power consumption, it is operated in an area adjacent to the linear area. In this case, the voltage level of the first power supply can be supplied to correspond to Equations 2 and 3 above. Accordingly, the organic light emitting diode is not supplied with an unnecessarily high voltage during operation, and the power consumption of the organic light emitting display device can be reduced. Additionally, the voltage applied to the organic light emitting diode can be lowered, thereby reducing the voltage stress of the organic light emitting diode.

After the organic light emitting display device stops operating, degradation information can be generated (S1210). In the process of generating degradation information, current flows through the organic light emitting diode, which allows the organic light emitting diode to emit light. However, it is not limited to this, and the voltage formed by the current generated in the process of generating deterioration information can be set to be lower than the threshold voltage of the organic light-emitting diode so that the organic light-emitting diode does not emit light. The degradation information may be generated after compensating for the threshold voltage of the first transistor of the subpixel. Deterioration information can be generated by sensing the voltage applied to the organic light emitting diode.

The voltage level of at least one of the first power source and the second power source can be changed in response to the deterioration information. (S1220) When the organic light emitting diode deteriorates, the luminous efficiency decreases, so even if the same voltage is applied, the deteriorated organic light emitting diode emits no light. The amount of light emitted decreases. Additionally, since the first transistor operates in the linear region, the change in current flowing through the organic light emitting diode increases. To solve this problem, by increasing the voltage level of the first power supply, the first transistor can be operated in the saturation region. However, it is not limited to this, and the voltage level of the second power source can be lowered.

The above description and attached drawings are merely illustrative of the technical idea of the present invention, and those skilled in the art will be able to combine the components without departing from the essential characteristics of the present invention. , various modifications and transformations such as separation, substitution, and change will be possible. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

100: Organic light emitting display device
101: Subpixel
110: display panel
120: data driver
130: gate driver
140: Timing controller
150: power unit

Claims (15)

A display panel including a plurality of subpixels;
a gate driver that supplies a gate signal to the display panel;
a data driver that supplies data signals to the display panel;
a power supply unit supplying first power and second power to the display panel; and
A voltage control unit that generates a voltage change signal in response to deterioration information of at least one subpixel among the plurality of subpixels,
The power unit changes the voltage level of at least one of the first power source and the second power source in response to the voltage change signal,
The power supply unit includes a transformer that receives an alternating current voltage having a first voltage level and changes it to a second voltage level, and a rectifier that rectifies the alternating voltage having the second voltage level output from the transformer, and the voltage change signal is an organic light emitting display device that adjusts the second voltage level output from the transformer.
According to paragraph 1,
The at least one subpixel includes a first transistor through which a driving current flows from the first electrode to the second electrode in response to the voltage of the gate electrode, and an organic light emitting diode that receives the driving current and emits light,
The voltage difference between the first power source and the second power source satisfies Equation 1 and Equation 2 below.
Equation 1
EVDD=Vd+Voled
Equation 2
Vds=Vgs-Vth
(Here, EVDD is the voltage level of the first power supply, Vd is the voltage of the first electrode of the first transistor, Voled is the voltage applied to the organic light emitting diode, and Vds is the voltage difference between the first electrode and the second electrode of the first transistor. , Vgs refers to the voltage difference between the gate electrode and the second electrode of the first transistor, and Vth refers to the threshold voltage of the first transistor.)
According to paragraph 2,
In the display panel, the first power is supplied through a plurality of power lines, and the at least one subpixel is a subpixel located at a predetermined distance from one side of the display panel to which the first power is supplied. .
According to paragraph 2,
The organic light emitting display device is an organic light emitting display device that emits one of red, green, blue, and white light.
According to paragraph 1,
The organic light emitting display device wherein the deterioration information corresponds to a preset first time.
According to paragraph 1,
An organic light emitting display device wherein the deterioration information is received from the at least one subpixel.
According to paragraph 1,
The voltage control unit receives the deterioration information and outputs the voltage change signal at a first preset time.
According to paragraph 1,
The organic light emitting display device wherein the data driver receives the deterioration information from the subpixel and transmits it to the voltage control unit.
delete A method of driving an organic light emitting display device comprising a display panel having a plurality of subpixels and a power supply unit supplying first power and second power to the display panel,
generating deterioration information of an organic light emitting diode included in at least one subpixel among the plurality of subpixels at a preset point in time; and
and changing the voltage level of at least one of the first power source and the second power source in response to the deterioration information,
In the step of generating the deterioration information, a voltage control unit generates a voltage change signal in response to the deterioration information,
In the step of changing the voltage level, the power unit changes the voltage level of at least one of the first power source and the second power source in response to the voltage change signal,
The power supply unit includes a transformer that receives an alternating current voltage having a first voltage level and changes it to a second voltage level, and a rectifier that rectifies the alternating voltage having the second voltage level output from the transformer, and the voltage change signal is a method of driving an organic light emitting display device that adjusts the second voltage level output from the transformer.
According to clause 10,
At least one subpixel among the plurality of subpixels includes a first transistor through which a driving current flows from the first electrode to the second electrode in response to the voltage of the gate electrode, and an organic light emitting diode that receives the driving current and emits light. ,
A method of driving an organic light emitting display device in which the voltage difference between the first power source and the second power source satisfies Equation 1 and Equation 2 below.
Equation 1
EVDD=Vd+Voled
Equation 2
Vds=Vgs-Vth
(Here, EVDD is the voltage level of the first power supply, Vd is the voltage of the first electrode of the first transistor, Voled is the voltage applied to the organic light emitting diode, and Vds is the voltage difference between the first electrode and the second electrode of the first transistor. , Vgs refers to the voltage difference between the gate electrode and the second electrode of the first transistor, and Vth refers to the threshold voltage of the first transistor.)
According to clause 11,
In the display panel, the first power is supplied through a plurality of power lines, and the at least one subpixel is a subpixel located at a predetermined distance from one side of the display panel to which the first power is supplied. Driving method.
According to clause 10,
A method of driving an organic light emitting display device in which the generating the degradation information generates the degradation information using a voltage applied to the organic light emitting diode.
According to clause 10,
A method of driving an organic light emitting display device in which the generating the deterioration information generates the deterioration information in response to an operation time of the display panel.
According to clause 11,
The method of generating the degradation information is performed after sensing the threshold voltage of the first transistor.

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