KR102460542B1 - Organic light emitting display and driving method for the same - Google Patents

Abstract

According to this embodiment, a display panel including a plurality of pixels, a sensing driving section for supplying a first sensing driving voltage to the display panel, and a sensing section for supplying a second sensing driving voltage are operated separately, but in the sensing section A drive IC corresponding to the second sensing driving voltage in response to the sensing control signal and sensing and outputting a pixel voltage applied to at least one pixel among the plurality of pixels, and outputting a sensing control signal when the temperature of the drive IC rises An object of the present invention is to provide an organic light emitting display device including a control unit receiving a pixel voltage from a drive IC and generating a correction signal, and a driving method thereof.
According to the organic light emitting display device and the driving method thereof according to the present embodiment, it is possible to prevent image quality deterioration by preventing a temperature change from occurring during sensing.

Description

Organic light emitting display device and driving method thereof

The present embodiments relate to an organic light emitting diode display and a driving method thereof.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and liquid crystal display devices (LCDs), plasma display devices, organic light emitting display devices ( Various types of display devices such as OLED: Organic Light Emitting Display Device) are being used.

Among these display devices, an organic light emitting display device emits light in response to a flow of a driving current driven by a driving transistor, and the amount of the driving current may vary depending on the high potential voltage supplied to the driving transistor and the voltage corresponding to the data signal. can In addition, the driving transistor has a threshold voltage deviation, and even when the same signal is transmitted to the driving transistor due to the deviation, the amount of the driving current to be driven is different. The image quality is not constant, so there may be a problem that the image quality is deteriorated. Accordingly, in order to solve the above problem, the organic light emitting display device senses the deviation of the threshold voltage of the driving transistor and corrects the flow of the driving current accordingly, thereby solving the problem of image quality degradation.

In particular, by sensing the voltage applied to the organic light emitting diode, sensing the threshold voltage, and correcting the image signal by generating a correction voltage corresponding to the sensed threshold voltage, it is possible to prevent deterioration of image quality. However, when generating the correction voltage, a difference may occur in the correction voltage generated when the ambient temperature is high and when the ambient temperature is low. Therefore, in order to solve this problem, a correction voltage may be generated using a device that is not sensitive to temperature change or further includes a heat sink.

However, when the heat sink is further provided, since components are added to the organic light emitting display device, the thickness of the organic light emitting display device may become thicker and manufacturing cost may increase. In addition, when a device that is not sensitive to temperature changes is used, there is a problem in that the manufacturing cost of the device is high and thus the manufacturing cost is increased.

An object of the present embodiments is to provide an organic light emitting display device capable of preventing image quality from being deteriorated by preventing a temperature change from occurring, and a driving method thereof.

Another object of the present embodiments is to provide an organic light emitting diode display capable of reducing manufacturing cost.

In one aspect, in the present embodiments, a display panel including a plurality of pixels, a first sensing driving voltage is supplied to the display panel in a sensing driving period to cause a temperature rise in response to the first sensing driving voltage, and the sensing period is A second sensing driving voltage is supplied to the display panel by a sensing control signal, and a pixel voltage corresponding to the second sensing driving voltage and applied to at least one of the plurality of pixels in a sensing section is received in response to the sensing control signal. An organic light emitting display comprising: a drive IC; and a control unit configured to receive a pixel voltage from the drive IC and generate a correction voltage by outputting the sensing control signal when the temperature of the drive IC rises to a constant temperature, a sensing period starts and outputs the sensing control signal to provide the device.

In another aspect, the present embodiments provide a driving method of an organic light emitting display device that generates a sensing signal by providing a sensing driving voltage to a drive IC for driving a display panel including a plurality of pixels, the first sensing driving a sensing driving step of supplying a voltage; and a sensing step of outputting a sensing control signal and sensing a pixel voltage applied to at least one of the plurality of pixels corresponding to the second sensing driving voltage and corresponding to the second sensing driving voltage when preset temperature information is received in response to the first sensing driving voltage. To provide a driving method of an organic light emitting display device comprising a.

According to the present embodiments, it is possible to provide an organic light emitting display device capable of preventing image quality deterioration due to temperature and a driving method thereof.

Also, according to the present exemplary embodiments, an organic light emitting display device capable of reducing the number of parts and reducing manufacturing cost can be provided.

1 is a structural diagram showing the structure of an organic light emitting display device according to the present embodiment.
FIG. 2 is a circuit diagram illustrating an embodiment of a pixel employed in the organic light emitting diode display shown in FIG. 1 .
3 is a waveform diagram illustrating an embodiment of a signal supplied to the pixel shown in FIG. 2 .
4 is a waveform diagram illustrating an embodiment of a signal supplied to pixels shown in odd-numbered and even-numbered columns of the display panel of FIG. 1 .
FIG. 5 is a structural diagram illustrating an embodiment of the drive IC shown in FIG. 1 .
6 is a structural diagram showing an embodiment of an ADC employed in the drive IC shown in FIG. 1 .
7 is a structural diagram showing an embodiment of the control unit shown in FIG.
FIG. 8 is a flowchart illustrating a driving method of the organic light emitting diode display shown in FIG. 1 .

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. However, 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.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It should be understood that each component may be “interposed” or “connected,” “coupled,” or “connected” through another component.

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

Referring to FIG. 1 , the organic light emitting display device 100 may include a display panel 110 , a drive IC 120 , and a controller 130 .

The display panel 110 may include a plurality of pixels 101 . The pixel 101 may be a unit expressing a specific grayscale and color by mixing red, green, blue, and/or white light in the display panel 110 . Also, the pixel 101 may be a unit that emits red, green, blue, or white light from the display panel 110 . Each pixel 101 may include an organic light emitting diode (not shown) and a pixel circuit (not shown) for allowing a driving current to flow through the organic light emitting diode. The plurality of pixels 101 are defined by gate lines G1, G2, ..., Gn-1, Gn and data lines D1, D2, ..., Dm-1, Dm intersecting in the display panel 110 . It may be disposed in the pixel area. Also, each pixel 101 may be disposed between a high potential line (not shown) supplying the high potential voltage EVDD and a low potential line (not shown) supplying the low potential voltage EVSS. A low potential line supplying the low potential voltage EVSS may be commonly connected to each of the pixels 101 . Also, the pixel 101 may be connected to a sensing signal line (not shown) capable of transmitting a sensing signal corresponding to the pixel voltage VS. The pixel voltage VS may be a voltage applied between the anode electrode and the cathode electrode of the organic light emitting diode. Also, the sensing signal line may transmit the first reference voltage Vref1 to the pixel.

Also, the display panel 110 may be divided into an active area AA displaying an image and an inactive area NAA not displaying an image, and the non-active area NAA includes a gate line from the drive IC 120 . Wires for transmitting gate signals and data signals to (G1, G2, ..., Gn-1, Gn) and data lines (D1, D2, ..., Dm-1, Dm) may be disposed, respectively. In addition, a gate in panel (GIP) circuit 112 may be disposed in the non-active area NAA, so that a gate control signal is received through the drive IC 120 to generate a gate signal to generate gate lines G1, G2, ... ,Gn-1,Gn).

Also, the display panel 110 may be driven in response to a normal mode for displaying an image and a sensing mode for sensing a pixel voltage VS applied to a pixel. In the normal mode, the display panel 110 generates and generates a driving current in the pixel circuit in response to the voltage of the data signal supplied to each pixel 101 through the data lines D1, D2, ..., Dm-1, Dm. By allowing the applied driving current to flow through the organic light emitting diode, light can be emitted to display an image. Also, the display panel 110 may transmit the pixel voltage VS to the drive IC 120 through the sensing signal line in the sensing mode. To this end, the sensing mode may be divided into a sensing driving section and a sensing section so that the display panel 110 can be driven. In the sensing driving period, the pixel 101 of the display panel 110 receives and receives the first reference voltage Vref1 from the pixel 101 through a sensing signal line (not shown), and the data lines D1, D2, ... , Dm-1, Dm) may receive the first sensing driving voltage. In the sensing period, the pixel 101 of the display panel 110 discharges the first reference voltage Vref1 and then receives the pixel voltage through the sensing line and transmits it to the drive IC 120 . In this case, the first reference voltage Vref1 through the data lines D1, D2, ..., Dm-1, Dm may be a voltage lower than the threshold voltage of the organic light emitting diode, so that even if the first sensing driving voltage is applied to the pixel, the pixel It is possible to prevent a driving current from being generated in the organic light emitting diode included in the light emitting diode. Then, when the pixel voltage VS is sensed in the sensing section, the low potential voltage EVSS connected to the cathode electrode of the organic light emitting diode is applied to the voltage level in the normal mode to prevent the driving current from flowing through the organic light emitting diode. It can be raised to more than a predetermined size. However, the present invention is not limited thereto, and the low potential voltage EVSS in the sensing mode period may be higher than the voltage level in the normal mode by a predetermined level or more.

The drive IC 120 may be connected to the data lines D1, D2, ..., Dm-1, Dm. Also, the drive IC 120 may transmit a data signal through the data lines D1, D2, ..., Dm-1, Dm in the normal mode. Also, the drive IC 120 may be connected to a gate line to transmit a gate signal. The drive IC 120 is controlled by the controller 130 , and may receive a gate control signal, a data control signal, and an image signal from the controller 130 , generate a gate signal and a data signal, and transmit the generated gate signal and data signal to the display panel 110 . In addition, the drive IC 120 may transmit the gate control signal to the GIP of the display panel 110 to generate the gate signal in the GIP. Also, the drive IC 120 may receive a sensing signal through a sensing signal line.

In addition, the drive IC 120 may transmit the first sensing driving voltage or the second sensing driving voltage through the data lines D1, D2, ..., Dm-1, Dm in the sensing mode. The sensing mode includes a sensing driving period in which the drive IC 120 supplies a first sensing driving voltage to the data lines D1, D2, ..., Dm-1, Dm, and the data lines D1, D2, ..., Dm-1. , Dm) in response to the sensing control signal, the second sensing driving voltage is transmitted to at least one pixel among the plurality of pixels, and a sensing period corresponding to the pixel voltage VS applied to the pixel is output. have. The drive IC 120 may operate to increase the temperature in the sensing driving section. In addition, when it is determined that the temperature of the drive IC 120 has reached a predetermined temperature, it may enter the sensing period to receive the pixel voltage VS. The received pixel voltage VS may be converted into a digital signal and transmitted to the controller 130 . In general, the amount of current flowing may be changed by temperature and the magnitude of the driving current may be changed in response to temperature, so that the voltage level of the pixel voltage VS sensed by the drive IC 120 has a variation according to temperature. can occur Also, when the correction voltage Va is generated using the pixel voltage VS, a deviation may occur in the correction voltage Va. In order to prevent deviation due to such temperature change, heat is emitted by using a heat sink or the like in the drive IC 120 to suppress the occurrence of temperature deviation. However, when a heat sink is inserted and mechanisms for fixing the heat sink are used, the thickness of the organic light emitting display device becomes thicker and manufacturing cost increases. In addition, when the drive IC 120 is manufactured using a device having a small variation due to a temperature rise, there is a problem in that the manufacturing cost of the drive IC 120 is high.

However, if the pixel voltage is sensed in a state where the temperature of the drive IC 120 is sufficiently raised, the sensed pixel voltage may not vary according to temperature because the temperature is already raised. Accordingly, there is no need to use a separate heat sink or expensive elements for the drive IC 120 , so that the organic light emitting diode display can be designed thinner and the manufacturing cost can be reduced.

Here, the drive IC 120 is illustrated as one individual, but this is exemplary and a plurality of drive ICs may be included to correspond to the resolution of the display panel 110 .

The controller 130 may control the drive IC 120 to drive the drive IC 120 . In addition, the control unit 130 may operate in response to the case of the normal mode and the case of the sensing mode. The controller 130 transmits an image signal in the normal mode and controls the drive IC 120 to display an image on the display panel 110 , and controls the drive IC 120 in the sensing mode to obtain a pixel voltage (VS). may be sensed and the image signal may be corrected by generating a correction voltage Va in response to the sensed pixel voltage VS. To this end, the controller 130 may determine the temperature of the drive IC 120 in the sensing driving period to enter the sensing period. The controller 130 may determine that the preset temperature is reached when the drive IC 120 maintains the sensing driving step for a preset time. Also, when entering the sensing period, the controller 130 may output a sensing control signal to sense the pixel voltage VS and calculate a correction voltage Va in response to the sensed pixel voltage VS.

In an embodiment, the organic light emitting display device 100 may further include a temperature sensor 140 for outputting temperature information. When the temperature sensor 140 senses the temperature of the drive IC 120 in the sensing mode and generates and outputs temperature information, the controller 130 controls the drive IC 120 according to the temperature information output from the temperature sensor 140 . It can be determined that the temperature corresponds to the preset temperature information, and if it is abnormal, the temperature of the drive IC 120 can be moved to the sensing step. When the sensing step is entered, the controller 130 may allow the drive IC 120 to sense the pixel voltage VS by outputting a sensing control signal. In addition, the preset temperature information may mean that the temperature of the drive IC 120 is higher than or equal to a certain temperature, and may mean that the temperature change occurs within a certain range after the temperature rises. However, the present invention is not limited thereto.

In an embodiment, the organic light emitting diode display 100 may further include a power supply unit 150 that supplies the high potential voltage EVDD through the high potential voltage line and the low potential voltage EVSS through the low potential line. have. The power supply unit 150 may be controlled by the control unit 130 . In addition, the power supply unit 150 may prevent the driving current from flowing to the organic light emitting diode by changing the voltage level of the low potential voltage EVSS in the sensing mode. The power supply unit 150 may transmit the first reference voltage Vref1 to the pixel to initialize the voltage stored in the pixel. In addition, the power supply unit 150 may transfer the second reference power Vref2 to the drive IC 120 to generate the correction voltage Va by using the voltage of the pixel voltage VS in the drive IC 120 . .

FIG. 2 is a circuit diagram illustrating an embodiment of a pixel employed in the organic light emitting diode display shown in FIG. 1 .

Referring to FIG. 2 , the pixel 201 may include an organic light emitting diode (OLED) and a pixel circuit 201a, respectively.

The organic light emitting diode (OLED) may emit light by flowing a driving current corresponding to the voltage of the anode electrode and the voltage of the cathode electrode. In addition, the organic light emitting diode (OLED) includes an organic layer and may emit red, green, blue, or white light by the organic layer.

The pixel circuit 201a may transmit a driving current to the organic light emitting diode (OLED). The pixel circuit 201a may include a first transistor M1 , a second transistor M2 , a third transistor M3 , and a capacitor C . Also, the first transistor M1 may be a driving transistor that generates a driving signal in response to the data signal.

The first transistor M1 has a first electrode connected to a high potential voltage line VL transmitting a high potential voltage EVDD, a gate electrode connected to a first node N1, and a second electrode connected to the second node ( N2) can be connected. The second node N2 may be connected to the anode electrode of the organic light emitting diode (OLED). In addition, the first transistor M1 may allow a driving current to flow from the first electrode to the second electrode in response to the voltage transmitted to the first node N1 .

The second transistor M2 has a first electrode connected to a data line DL through which a data voltage or a first sensing driving voltage and a second sensing driving voltage are transmitted, a second electrode connected to a first node N1, and a gate An electrode may be connected to the gate line GL. In addition, the data voltage or the first sensing driving voltage and the second sensing driving voltage transmitted through the data line DL in response to the gate signal transmitted through the gate line GL are transmitted to the first node N1. can

The third transistor M3 may have a first electrode connected to the sensing line SL, a second electrode connected to the second node N2 , and a gate electrode connected to the sensing control signal line SSL. The third transistor M3 may transmit the pixel voltage VS to the sensing line SL in response to the sensing control signal transmitted through the sensing control signal line SSL. Also, the third transistor M3 may transmit the first reference voltage Vref1 to the second node N2 in response to the sensing control signal.

The capacitor C is disposed between the first node N1 and the second node N2, and may maintain the voltage of the first node N1 in response to the voltage stored in the capacitor C. Also, the voltage stored in the capacitor C may be initialized by the first reference voltage Vref1 transmitted through the sensing line SL connected to the second node N2 .

In addition, the pixel circuit 201a receives a signal from the data line DL and is connected to an output buffer 223 that outputs a data voltage or a first sensing driving voltage or a second sensing driving voltage, and the sensing line is connected to the switch unit 202 . ) may be selectively connected to the sample/hold circuit 221 . The sample/hold circuit 221 may be included in the drive IC 120 of FIG. 1 . Also, the sensing line SL may selectively receive the first initialization voltage VSPRE and the second initialization voltage VRPRE through the switch unit 202 . Here, the voltage level of the second initialization voltage VRPRE may be the first reference voltage Vref1. The switch unit 202 selects the first switch S1 to be selectively connected to the sample/hold circuit 221 in response to the first switch signal and the first initialization voltage VSPRE in response to the second switch signal. and a second switch S2 and a third switch S3 that selects the second initialization voltage VRPRE in response to the third switch signal. Here, the sample/hold circuit 221 may be connected through the first switch S1 and store the pixel voltage. In addition, each pixel shown in FIG. 1 is connected to a sample/hold circuit 221 for each sensing line, and the sample/hold circuit 221 transmits the stored pixel voltage to an ADC (not shown) to calculate a correction voltage. It can be converted to a digital signal.

3 is a waveform diagram illustrating an embodiment of a signal supplied to the pixel shown in FIG. 2 .

Referring to FIG. 3 , the pixel 201 may be operated by being divided into a sensing driving period T11 and a sensing period T112 . The sensing driving section T11 and the sensing section T2 may be operated separately by the controller 130 shown in FIG. 1 . Also, when the temperature of the drive IC 120 reaches a preset temperature, the controller 130 may terminate the sensing driving period T1 and enter the sensing period T2. In addition, when the sensing driving period T1 in the drive IC 120 continues for a preset period, the driving IC 120 may enter the sensing period T2. However, the present invention is not limited thereto. In addition, the gate signal G, the sensing signal SS, the first switch signal SAM, the second switch signal SPRE, and the third switch signal RPRE are output from the control unit 130 shown in FIG. The control signal may be generated in the drive IC 120 and supplied to the pixel. However, the present invention is not limited thereto, and the first switch signal SAM, the second switch signal SPRE, and the third switch signal RPRE may be supplied from the controller 130 to the switch unit 202 .

First, in the sensing driving period T11, the gate signal G and the sensing signal SS may be supplied in a low state. In addition, the first switch signal SAM, the second switch signal SPRE, and the third switch signal RPRE may be supplied in a low state. In addition, the first sensing driving voltage Vdata1 may repeatedly represent a low state and a high state. The first sensing driving voltage Vdata1 may repeatedly represent a low state and a high state in response to a signal generated by the controller 130 . However, the present invention is not limited thereto, and it is also possible to generate a signal in which the low state and the high state are repeated by the driver IC 120 without receiving the data signal from the controller 130 . In addition, the first reference voltage Vref1 may be maintained in a high state so that the voltage of the sensing line may be maintained in a high state. Also, the low potential voltage EVSS may be lower than the high potential voltage ELVDD. However, the low potential voltage EVSS may be a voltage higher than a voltage in a low state applied to the low potential voltage when the display panel 110 is driven in the normal mode. When driven in the normal mode, the low potential voltage may be “0V”. However, the present invention is not limited thereto.

In addition, the voltage applied to the low potential voltage line may be a voltage such that the voltage difference between the anode electrode and the cathode electrode of the organic light emitting diode (OLED) is lower than the threshold voltage of the organic light emitting diode (OLED). Accordingly, since the voltage difference between the anode electrode and the cathode electrode of the organic light emitting diode in the sensing driving period T11 is lower than the threshold voltage of the organic light emitting diode OLED, the organic light emitting diode does not emit light.

When the gate signal is in the low state, the first sensing driving voltage Vdata1 supplied from the drive IC 120 may not be transmitted to the pixel circuit because the second transistor M2 is in the off state. Also, when the sensing control signal SS is in the low state, the sensing line and the pixel circuit may be short-circuited because the third transistor M3 is in the off state. In addition, the first switch S1, the second switch S2, and the third switch S3 are turned off by the first switch signal SAM, the second switch signal SPRE, and the third switch signal RPRE, respectively. state can be maintained. At this time, the output buffer 223 of the drive IC may operate so that the first sensing driving voltage Vdata1 may repeatedly show a high state and a low state. When the output buffer 223 of the drive IC repeatedly outputs a high state and a low state, heat is generated in the output buffer 2223 and the temperature of the drive IC 120 may rise.

Then, when it is determined that the temperature of the drive IC 120 has reached a predetermined temperature, the sensing period T21 may be entered. When entering the sensing period T2, the gate signal G and the sensing control signal SS may be in a high state, and the high state may be maintained in the sensing period T2. In addition, the second sensing driving voltage Vdata2 may be supplied to the data line DL.

When the gate signal G is in a high state, the second transistor M2 is turned on and the second sensing driving voltage Vdata2 transmitted through the data line DL may be transmitted to the first node N1 . And, when the sensing signal SS is in a high state, the third transistor M3 may be turned on. Also, when the gate signal G and the sensing signal SS turn to the high state, the second switch signal SPRE may be in the high state to turn on the second switch S2 . After maintaining the high state for a predetermined period of time, the second switch signal may be in the low state again in the sensing period T2. When the second switch S2 is turned on, the first initialization voltage VSPRE applied to the sensing line SL may be transmitted, and the first reference voltage Vref1 may be discharged through the second switch S2 . When the first reference voltage Vref1 is discharged, the voltage of the second node N2 may drop from a high state to a first initialization voltage VSPRE, which is a low state.

In addition, the first transistor M1 may supply a driving current in the direction of the second node by the second sensing driving voltage Vdata2 transmitted to the first node N1 . At this time, the voltage of the capacitor C is charged by the driving current and the voltage of the second node N2 is increased. The slope at which the voltage of the second node N2 rises may correspond to the magnitude of the driving current. Then, when the voltage of the second node N2 starts to rise and a predetermined time elapses, the first switch S1 is turned on by the first switch signal SAM, and the sample/hold circuit 221 is connected to the sensing line. (SL) can be connected. In addition, the sample/hold circuit 221 may store a pixel voltage that is the voltage of the second node N2 . In addition, the sample/hold circuit 221 may transmit a pixel voltage (the voltage of the second node N2 ) to the ADC (not shown) and generate a correction voltage from the ADC. The ADC may receive a plurality of pixel voltages and generate a correction voltage for each pixel.

In general, when the ADC generates a correction voltage by sensing the pixel voltage, a deviation in the correction voltage may occur due to a change in temperature. However, if the pixel voltage is sensed after raising the temperature of the drive IC in the sensing driving section, the temperature rises sufficiently, so that the temperature change may not occur when the ADC generates the correction voltage. For this reason, the deviation of the correction voltage does not occur, and thus it is possible to prevent deterioration of image quality due to the deviation of the correction voltage. The temperature change can be detected using the temperature sensor 140 shown in FIG. 1 , and when the sensing driving section is maintained for a predetermined time T1 or longer, it can be determined that preset constant temperature information is generated. Accordingly, even if the temperature sensor 140 is not provided, it can operate in response to the temperature. In addition, when used in a cold region, the sensing mode may be operated even if the preset temperature does not rise.

4 is a waveform diagram illustrating an embodiment of a signal supplied to pixels shown in odd-numbered and even-numbered columns of the display panel of FIG. 1 .

The plurality of pixels included in the display panel may be divided into at least a first group and a second group different from the first group. In addition, when the pixels of the first group operate in response to the sensing period by the controller, the pixels in the second group may operate in response to the sensing driving period, and the pixels of the first group operate in response to the sensing driving period In this case, the pixels of the second group may operate corresponding to the sensing period. The first group of pixels may mean pixels arranged in odd-numbered columns of the display panel 110 illustrated in FIG. 1 , and the second group of pixels may mean pixels arranged in even-numbered columns of the display panel. Also, odd-numbered columns and even-numbered columns may be distinguished corresponding to data lines. However, the present invention is not limited thereto.

Referring to FIG. 4 , pixels arranged in odd-numbered columns may operate in response to a sensing period in a first frame 1Frame, and pixels arranged in even-numbered columns may operate in correspondence to a sensing driving period. Further, in the second frame (2Frame), pixels arranged in odd-numbered columns may operate in response to the sensing driving period, and pixels arranged in even-numbered columns may operate in correspondence to the sensing period.

First, in a first frame (1Frame), the gate signal and the sensing control signal are in a high state and can be maintained in a high state for a predetermined time. In addition, the second switch signal SPRE_O connected to the odd-numbered sensing line maintains a high state for a predetermined time when the gate signal and the sensing control signal are in the high state. The third switch signal RPRE_O connected to the odd-numbered sensing line maintains a low state. In addition, the second sensing driving voltage Vdata2 may be applied to the odd-numbered data line.

The gate signal and the sensing control signal maintain a high state, so that the second transistor connected to the odd-numbered data line and the third transistor connected to the odd-numbered sensing line are turned on. In addition, the second switch signal SPRE_O is turned on and the first reference voltage REF1_O applied to the odd-numbered sensing line may be discharged by the second switch signal SPRE_O. After the first reference voltage REF1_O is discharged, the pixel voltage becomes After being charged, the voltage level of the first reference voltage REF1_O may increase. In addition, after a predetermined time has elapsed, the pixel voltage may be transferred to the sample/hold circuit connected to the odd-numbered sensing line by the first switch signal SAM_O, so that it may operate in response to the sensing period.

In addition, the second switch signal SPRE_E connected to the even-numbered sensing line may maintain a low state, and the third switch signal RPRE_E connected to the odd-numbered sensing line may maintain a high state. Accordingly, the second initialization voltage Vinit2 may be transmitted to the even-numbered sensing line, and the first reference voltage REF1_E may be applied to the even-numbered sensing line. A first sensing driving voltage Vdata1 in which a high state and a low state repeatedly appears may be applied to the data line. In addition, the gate signal G and the sensing control signal SS maintain a high state, so they are respectively connected to the data lines of the even columns and the sensing lines of the even columns as in the pixel 201 shown in FIG. The transistor and the third transistor may be turned on. In addition, when the second transistor is turned on, a voltage corresponding to the first sensing driving voltage Vdata1 may be applied to the gate electrode of the first transistor, but the first reference voltage applied to the even-numbered sensing line by the third transistor is induced. The driving current may not flow through the organic light emitting diode by being applied to the anode electrode of the light emitting diode. In addition, the output buffer connected to the even-numbered data line by the first sensing driving voltage repeatedly outputs a high-state signal and a low-state signal to generate heat in the output buffer, which causes the temperature of the drive IC to rise. It can be operated in response to the sensing driving section.

Also, in the second frame, pixels connected to an odd-numbered sensing line may operate in response to a sensing driving period, and pixels connected to an even-numbered sensing line may operate in response to a sensing period. After the temperature rises through the sensing driving section, there is a risk that the temperature will decrease when the sensing section is completed and the sensing section is performed. .

FIG. 5 is a structural diagram illustrating an embodiment of the drive IC shown in FIG. 1 .

Referring to FIG. 5 , the drive IC 520 may include a latch 521 , a DAC 522 , and an output buffer 523 .

The latch 521 may receive the image signal RGB from the controller 130 shown in FIG. 1 and output data voltages in parallel. The data voltage output from the latch 521 may be a digital signal. The DAC 522 may receive the parallel data voltage output from the latch 521 and output it as an analog data voltage. Also, the DAC 522 may output the first sensing driving voltage and the second sensing driving voltage in response to the signal received from the controller 130 . Here, the first sensing driving voltage may be a signal in which a data voltage corresponding to the first gray level and a data voltage corresponding to the second gray level are repeatedly output. The first grayscale may correspond to the highest grayscale, and the second grayscale may correspond to the O grayscale. However, the present invention is not limited thereto, and the first strong driving voltage may be a voltage in which a high-state voltage and a low-state voltage repeatedly appear, and the high-state voltage may be a voltage higher than a voltage corresponding to the highest gray level. The output buffer 523 may output the voltage output from the DAC 522 to the data lines D1, D2, ..., Dm-1, Dm. When the output buffer 523 repeatedly outputs the data voltage corresponding to the first grayscale and the data voltage corresponding to the second grayscale, heat is generated, which may increase the temperature of the drive IC 520 .

Accordingly, in the same section, there may be pixels operating in response to the sensing section, and there may be pixels operating in response to the sensing driving section.

6 is a structural diagram illustrating an embodiment of the drive IC shown in FIG. 1 .

Referring to FIG. 6 , the drive IC 620 may include a sample/hold circuit 621 and an ADC 622 .

The ADC 622 may receive the pixel voltage VS from the sample/hold circuit 621 , and may receive a first voltage V1 in a high state and a second voltage V2 in a low state. Here, the first voltage V1 and the second voltage V2 may be the second reference voltage Vref2 shown in FIG. 1 . In addition, the voltage of the pixel voltage VS may be converted to the correction voltage Va by using the first voltage V1 and the second voltage V2. The correction voltage Va may be output as a digital signal. In this case, the ADC 622 may have a different magnitude of the correction voltage Va output when the ambient temperature is room temperature and when the ambient temperature is high. In addition, if the magnitude of the correction voltage is different, the correction of the image signal has a different value depending on the temperature, so that the correction of the image signal is not performed accurately. Accordingly, the ADC 622 calculates a correction voltage in a high temperature state so that the magnitude of the correction voltage can be output according to the characteristics of the pixel.

7 is a structural diagram showing an embodiment of the control unit shown in FIG.

Referring to FIG. 7 , the control unit 700 receives the correction voltage Va and receives the correction coefficient calculated from the operation unit 710 for calculating the correction coefficient and the image signal RGB and the operation unit 710 to receive the correction image signal. It may include a correction unit 720 that outputs (RGBa).

The calculator 710 may calculate the correction coefficient G in response to the received correction voltage Va using a predetermined algorithm. Since the correction voltage Va is a voltage corresponding to the driving current flowing by the first transistor of the pixel, it is possible to determine the characteristics of the first transistor corresponding to the magnitude of the correction voltage Va. A correction coefficient G according to a change in the characteristics of may be generated for each pixel by using the correction voltage Va. The correction voltage Va stores the correction voltage Va calculated by the ADC 622 shown in FIG. 6 in a memory (not shown), and the operation unit 710 stores the correction voltage Va for each pixel in the memory ( Va) may be used to calculate the correction coefficient G for each pixel.

The correction unit 720 may calculate the corrected image signal RGBa by applying the correction coefficient calculated for each pixel to the image signal RGB. The corrector 720 may calculate the corrected image signal RGBa by adding the correction coefficient to the image signal RGB. However, the present invention is not limited thereto.

FIG. 8 is a flowchart illustrating a driving method of the organic light emitting diode display shown in FIG. 1 .

Referring to FIG. 8 , in the driving method of the organic light emitting display device, when a sensing driving step ( S800 ) of supplying a first sensing driving voltage and preset temperature information corresponding to the first sensing driving voltage is received, a sensing control signal is generated. A sensing step ( S810 ) of sensing a pixel voltage corresponding to the second sensing driving voltage and applied to at least one pixel among the plurality of pixels by outputting the sensing step ( S810 ) may be included. In addition, the method may further include a correction step ( S820 ) of correcting the image signal in response to the sensed pixel voltage.

The sensing driving step ( S800 ) is a step to increase the temperature of the drive IC. If a high signal and a low signal are repeated at the output terminal of the drive IC, the temperature of the drive IC may increase. In more detail, if the output buffer of the drive IC repeatedly outputs the high signal and the low signal, the output buffer generates heat, which may increase the temperature of the drive IC. The drive IC may repeatedly output a high signal and a low signal in response to the first sensing driving voltage. The high signal may be a voltage corresponding to the first grayscale, and the low signal may be a voltage corresponding to the second grayscale. Also, the first grayscale may be the highest grayscale and the second grayscale may be the 0 grayscale. However, the present invention is not limited thereto, and the high signal may be a voltage higher than a voltage corresponding to the highest gray level.

The sensing step ( S810 ) is a step in which it is entered when it is determined that the temperature of the drive IC has become the preset temperature information. The preset temperature information may be information about a temperature higher than or equal to a preset temperature, and may be information about a time during which the temperature does not rise any more and is kept constant. The preset temperature information may be determined by measuring the temperature of the drive IC using a temperature sensor. In addition, if the drive IC continues the sensing driving step for a predetermined time, it may be determined that a predetermined temperature has been reached, and it may be determined that the preset temperature information has occurred after the sensing driving step has been continued for a predetermined time. When the sensing step is entered, the drive IC may output a second sensing driving voltage, and a pixel voltage generated in response to the output second sensing driving voltage may be transmitted to the drive IC.

In the correction step S820 , a correction voltage may be generated from the drive IC receiving the pixel voltage and transmitted to the controller, and the controller may correct the image signal RGB using the received correction voltage. When the temperature is different when generating the correction voltage, the correction voltage is deviated. Due to this deviation, the image signal RGB is not accurately corrected, resulting in deterioration of image quality. However, when generating the correction voltage in the drive IC, if the temperature is sufficiently raised in the sensing driving step (S800) and the correction voltage is generated, the temperature deviation does not occur and the image signal (RGB) is accurately corrected. There may be no deterioration in image quality.

In addition, when sensing is performed in a state in which the temperature is sufficiently raised in the sensing driving step ( S800 ), when the sensing driving step ( S800 ) is terminated and the sensing step ( S810 ) is performed, the temperature of the drive IC may drop. When the temperature drops in this way, there may be room for temperature deviation to occur. Therefore, when the temperature is sufficiently raised in the sensing driving step S800 to solve this problem, first, the pixels arranged in odd-numbered columns of the display panel perform the sensing driving step, and the pixels arranged in even-numbered columns perform the sensing step. In addition, the temperature of the drive IC can be prevented from falling in the sensing mode by allowing the pixels arranged in odd columns of the display panel to perform the sensing step and the pixels arranged in even columns to perform the sensing driving step. Here, although the description has been made by dividing the odd number and the even number, this is illustrative and not limited thereto.

The above description and the accompanying drawings are merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains can combine configurations within a range that does not depart from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: organic light emitting display device
101: pixel
110: display panel
120: drive IC
130: control unit
140: temperature sensor
150: power supply

Claims (15)

a display panel including a plurality of pixels;
In the sensing driving period, a first sensing driving voltage is supplied to the display panel to cause a temperature rise in response to the first sensing driving voltage, and in the sensing period, a second sensing driving voltage is supplied to the display panel by a sensing control signal. a drive IC corresponding to the second sensing driving voltage in the sensing period and receiving a pixel voltage applied to at least one of the plurality of pixels in response to a sensing control signal; and
and a controller configured to receive the pixel voltage from the drive IC and generate a correction voltage by outputting the sensing control signal when the temperature of the drive IC rises to a constant temperature, and the sensing period starts. . According to claim 1,
The organic light emitting display device further comprises a temperature sensor for sensing a temperature, wherein the control unit outputs the sensing control signal when the temperature sensor detects a preset temperature. According to claim 1,
The control unit determines that a constant temperature has been reached when the sensing driving period elapses for a predetermined time and outputs the sensing control signal. According to claim 1,
dividing the plurality of pixels into at least a first group and a second group different from the first group;
The control unit causes the second group to operate in response to the sensing section when the first group operates in response to the sensing driving section, and when the first group operates in response to the sensing section, the second group An organic light emitting display device to operate in response to the sensing driving period. According to claim 1,
The drive IC further includes an ADC, wherein the ADC compares a preset reference voltage with the pixel voltage to generate a correction voltage. 6. The method of claim 5,
The control unit further comprises: an arithmetic unit configured to receive the correction voltage and calculate a correction coefficient; and a correction unit configured to correct an image signal by calculating the correction coefficient corresponding to the correction coefficient. According to claim 1,
The display panel operates in a sensing mode and a normal mode,
At least one pixel among the plurality of pixels is disposed between a high potential voltage supplied through a first power line supplying a high potential voltage and a second power line supplying a low potential voltage, and in the sensing mode, the low potential The voltage level of the voltage is set to be higher in the normal mode in at least a sensing period of the sensing period and the sensing driving period. According to claim 1,
The drive IC includes a latch unit for generating a data voltage in response to an image signal and an output buffer for outputting the data voltage;
The first sensing driving voltage is a voltage that causes the output buffer to alternately output a high-state voltage and a low-state voltage. A method of driving an organic light emitting display device for generating a sensing signal by providing a sensing driving voltage to a driving IC for driving a display panel including a plurality of pixels, the method comprising:
a sensing driving step of supplying a first sensing driving voltage; and
A sensing step of outputting a sensing control signal and sensing a pixel voltage applied to at least one pixel among the plurality of pixels corresponding to the second sensing driving voltage and outputting a sensing control signal when preset temperature information is received in response to the first sensing driving voltage A driving method of an organic light emitting display device comprising a. 10. The method of claim 9,
The preset temperature information is generated by sensing the temperature of the drive IC. 10. The method of claim 9,
The driving method of the organic light emitting display device for determining that the preset temperature information has reached the preset temperature information when the sensing and driving step has elapsed for a preset time. 10. The method of claim 9,
dividing the plurality of pixels into at least a first group and a second group different from the first group;
When the first group operates in response to the sensing and driving step, the second group operates in response to the sensing step. 10. The method of claim 9,
The display panel is driven by being divided into a sensing mode and a normal mode,
At least one pixel among the plurality of pixels is disposed between a high potential voltage supplied through a first power line supplying a high potential voltage and a second power line supplying a low potential voltage, and in the sensing mode, the low potential The voltage level of the voltage is set to be higher in the normal mode in at least the sensing step of the sensing driving step and the sensing step. 10. The method of claim 9,
and a correction step of correcting an image signal in response to the sensing signal. 10. The method of claim 9,
The first sensing driving voltage is a driving method of an organic light emitting display device in which a high-state voltage and a low-state voltage are alternately output.

Images