KR20180039810A - Organic light emitting display and driving method for the same - Google Patents

Abstract

The present invention provides an organic light emitting display device and a driving method thereof. According to an embodiment of the present invention, the organic light emitting display device comprises: a display panel including multiple pixels; a drive integrated circuit (IC) which operates in a sensing driving section for supplying a first sensing driving voltage to the display panel and in a sensing section for supplying a second sensing driving voltage in a separated manner as well as sensing and outputting a pixel voltage to be applied to one or more pixels among the pixels in correspondence with the second sensing driving voltage in response to sensing control signals in the sensing section; and a control unit which outputs the sensing control signals and receives the pixel voltage from the drive IC when the temperature of the drive IC rises to generate correction signals. The organic light emitting display device, as well as the driving method for the same, can prevent image definition degradation by preventing temperature changes in a sensing operation.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display device,

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

BACKGROUND ART Demands for a display device for displaying an image have been increasing in various forms as an information society has developed. In addition, a liquid crystal display device (LCD), a plasma display device (Plasma Display Device) OLED (Organic Light Emitting Display Device), and the like.

Among these display devices, the OLED display emits light corresponding to the flow of the driving current driven by the driving transistor. The amount of the driving current varies depending on the high-potential voltage supplied to the driving transistor and the voltage corresponding to the data signal . Also, even if the same signal is transmitted to the driving transistor due to such a deviation, there is a difference in the amount of the driving current to be driven and a difference occurs in the amount of light emitted thereby, The quality of the image may not be constant and the quality of the image may deteriorate. Therefore, in order to solve the above problems, the organic light emitting display can solve the problem that the image quality deteriorates by sensing the deviation of the threshold voltage of the driving transistor and correcting the flow of the driving current correspondingly.

In particular, a voltage applied to the organic light emitting diode is sensed to sense a threshold voltage, a correction voltage corresponding to the sensed threshold voltage is generated, and a video signal is corrected to prevent image quality degradation. However, when generating the correction voltage, a difference may occur in the correction voltage that is generated when the ambient temperature is high or when the ambient temperature is high. Therefore, in order to solve such a problem, it is possible to generate a correction voltage by using a device having a heat sink or not sensitive to a temperature change.

However, if a heat sink is further provided, the thickness of the organic light emitting display device may be thicker and the manufacturing cost may be increased because a component is added to the organic light emitting display device. Further, when a device which is not sensitive to temperature changes is used, there is a problem that the manufacturing cost is increased due to a high manufacturing cost of the device.

It is an object of the present embodiments to provide an organic light emitting display device and a method of driving the same that can prevent image quality from being degraded by preventing a temperature change from occurring.

It is still another object of the present embodiments to provide an organic light emitting display device capable of reducing manufacturing costs.

In one aspect, the present embodiments provide 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 corresponding to a first sensing driving voltage, A second sensing driving voltage is supplied to the display panel by a sensing control signal and a pixel voltage corresponding to a second sensing driving voltage in a sensing period and applied to at least one of the plurality of pixels is received in response to a sensing control signal And a control unit for generating a correction voltage by receiving the pixel voltage from the drive IC by outputting the sensing control signal when the temperature of the drive IC and the drive IC reaches a predetermined temperature, Device.

According to another aspect of the present invention, there is provided a driving method of an organic light emitting display device which generates a sensing signal by providing a sensing driving voltage to a driving IC driving a display panel including a plurality of pixels, A sensing driving step of supplying a voltage; And a sensing step of outputting a sensing control signal and sensing a pixel voltage corresponding to a second sensing driving voltage and being applied to at least one of the plurality of pixels when preset temperature information corresponding to the first sensing driving voltage is received, And a method of driving the organic light emitting display device.

According to the embodiments, it is possible to provide an organic light emitting display device and a method of driving the same that can prevent image quality deterioration due to temperature.

According to the embodiments, it is possible to provide an organic light emitting display device capable of reducing the number of parts and lowering the manufacturing cost.

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

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

1 is a structural view illustrating a structure of an OLED display according to an embodiment of the present invention.

1, the organic light emitting diode display 100 may include a display panel 110, a driver IC 120, and a controller 130.

The display panel 110 may include a plurality of pixels 101. The pixel 101 may be a unit for expressing a specific gradation and color by mixing red, green, blue, and / or white light in the display panel 110. In addition, the pixel 101 may be a unit that emits red, green, blue, or white light in the display panel 110, respectively. Each pixel 101 may include an organic light emitting diode (not shown) and a pixel circuit (not shown) for causing a driving current to flow through the organic light emitting diode. The plurality of pixels 101 are defined by the gate lines G1, G2, ..., Gn-1, Gn and the data lines D1, D2, ..., Dm-1, Dm intersecting in the display panel 110 And may be disposed in the pixel region. Each pixel 101 may be disposed between a high potential line (not shown) for supplying a high potential voltage EVDD and a low potential line (not shown) for supplying a low potential potential EVSS. The low potential line supplying the low potential voltage EVSS can be commonly connected to each pixel 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. Further, the sensing signal line may transmit the first reference voltage Vref1 to the pixel.

The display panel 110 may be divided into an active area AA for displaying an image and an inactive area NAA for not displaying an image. In the non-active area NAA, Wirings for transferring gate signals and data signals to the data lines D1, D2, ..., Dm-1, Dm and the data lines D1, D2, ..., Dm-1, Dm. A GIP (Gate In Panel) circuit 112 may be disposed in the non-active area NAA to receive a gate control signal 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 the pixel. In the normal mode, the display panel 110 generates a driving current in the pixel circuit corresponding to the voltage of a data signal supplied to each pixel 101 through the data lines D1, D2, ..., Dm-1, The driving current is allowed to flow through the organic light emitting diode so that light can be emitted to display an image. In addition, the display panel 110 can transmit the pixel voltage VS to the drive IC 120 through the sensing signal line in the sensing mode. For this, the sensing mode may be divided into a sensing driving period and a sensing period so that the display panel 110 may be driven. In the sensing driving period, the pixel 101 of the display panel 110 receives and receives the first reference voltage Vref1 through the sensing signal line (not shown) to the pixel 101, and the data line D1, D2, ..., , Dm-1, and Dm, respectively. In the sensing period, the pixel 101 of the display panel 110 may discharge the first reference voltage Vref1, receive the pixel voltage through the sensing line, and transmit the pixel voltage to the drive IC 120. [ At this time, the first reference voltage Vref1 may be lower than the threshold voltage of the organic light emitting diode through the data lines D1, D2, ..., Dm-1, Dm so that even if the first sensing driving voltage is applied to the pixel, It is possible to prevent a driving current from being generated in the organic light emitting diode included in the organic light emitting diode. In order to prevent the driving current from flowing to the organic light emitting diode when sensing the pixel voltage VS in the sensing period, the low potential voltage EVSS connected to the cathode electrode of the organic light emitting diode is set to a voltage level in the normal mode Can be increased to a predetermined size or more. However, the present invention is not limited to this, and in the sensing mode period, the low potential EVSS 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. Further, the drive IC 120 can transfer the data signal through the data lines D1, D2, ..., Dm-1, and Dm in the normal mode. In addition, 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 receives a gate control signal, a data control signal, and a video signal from the controller 130 to generate a gate signal and a data signal, and can transmit the gate signal and the data signal to the display panel 110. In addition, the drive IC 120 may transmit a gate control signal to the GIP of the display panel 110 to generate a gate signal in the GIP. In addition, the drive IC 120 can receive the sensing signal through the sensing signal line.

Also, 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, and Dm in the sensing mode. The sensing mode includes a sensing driving period in which the driving IC 120 supplies a first sensing driving voltage to the data lines D1, D2, ..., Dm-1, Dm and a sensing driving period during which the data lines D1, , And Dm) to the at least one pixel among the plurality of pixels in response to the sensing control signal, and outputting a sensing signal corresponding to the pixel voltage (VS) applied to the pixel have. The drive IC 120 can operate so that the temperature rises in the sensing driving period. If it is determined that the temperature of the drive IC 120 has reached a predetermined temperature, it can enter the sensing period and receive the pixel voltage VS. The received pixel voltage VS may be converted into a digital signal and transmitted to the controller 130. Generally, the amount of current flowing by the temperature can be changed and the magnitude of the driving current corresponding to the temperature can be changed, so that the voltage level of the pixel voltage VS sensed by the drive IC 120 is varied with temperature Lt; / RTI > In addition, a deviation may occur in the correction voltage Va when the correction voltage Va is generated using the pixel voltage VS. In order to prevent such a variation due to the temperature change, a heat radiating plate or the like is used to dissipate heat to the drive IC 120 to suppress the occurrence of a temperature deviation. However, if the heat sink is inserted and the fixtures are used, the thickness of the organic light emitting display may be thicker and the manufacturing cost may be increased. In addition, when the drive IC 120 is manufactured using a device having a small deviation due to a temperature rise, there is a problem that the manufacturing cost of the drive IC 120 becomes high.

However, if the pixel voltage is sensed while the temperature of the drive IC 120 is sufficiently raised, the temperature of the sensed pixel voltage may not fluctuate with temperature. Therefore, it is not necessary to use a separate heat radiating plate for the drive IC 120 or to use an expensive device, so that the organic light emitting display device can be designed to be thinner, and the manufacturing cost can be reduced.

Here, although the drive IC 120 is shown as one individual, it may be a plurality of drive ICs corresponding to the resolution of the display panel 110 as an example.

The control unit 130 controls the drive IC 120 to drive the drive IC 120. [ In addition, the controller 130 can operate in the normal mode and the sensing mode. The controller 130 transmits the video signal in the normal mode and controls the drive IC 120 to display an image on the display panel 110. The controller 130 controls the drive IC 120 in the sensing mode, And corrects the video signal by generating a correction voltage Va corresponding to the sensed pixel voltage VS. For this, the controller 130 may determine the temperature of the drive IC 120 in the sensing driving period and enter the sensing period. The control unit 130 may determine that the predetermined temperature has been reached when the drive IC 120 maintains the sensing driving phase for a predetermined time. In addition, when the controller 130 enters the sensing period, the controller 130 outputs a sensing control signal to sense the pixel voltage VS and to calculate the correction voltage Va in accordance with the sensed pixel voltage VS.

In one embodiment, the OLED display 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 and generates and outputs temperature information in the sensing mode, the controller 130 controls the temperature of 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 the temperature is abnormal, the temperature of the drive IC 120 can be made to go into the sensing step. The controller 130 outputs a sensing control signal so that the drive IC 120 can sense the pixel voltage Vs. In addition, the predetermined temperature information may indicate that the temperature of the drive IC 120 is higher than a certain temperature, and may mean that the temperature change occurs below a certain range after the temperature rises. However, the present invention is not limited thereto.

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

2 is a circuit diagram showing one embodiment of a pixel employed in the organic light emitting display shown in FIG.

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

The organic light emitting diode OLED emits light by flowing a driving current corresponding to the voltage of the anode electrode and the voltage of the cathode electrode. Further, the organic light emitting diode (OLED) is an organic film and can emit light of red, green, blue or white by an organic film.

The pixel circuit 201a can 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. The first transistor M1 may be a driving transistor for generating a driving signal corresponding to a data signal.

The first transistor M1 has a first electrode connected to a high potential line VL carrying a high potential EVDD and a gate electrode connected to a first node N1 and a second electrode connected to a second node N1. N2. And the second node N2 may be connected to the anode electrode of the organic light emitting diode OLED. The first transistor M1 may cause the driving current to flow from the first electrode to the second electrode corresponding to the voltage transmitted to the first node N1.

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

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 a 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 can maintain the voltage of the first node N1 corresponding to the voltage stored in the capacitor C. [ In addition, 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.

The sensing line is connected to an output buffer 223 which receives a signal from the data line DL to the pixel circuit 201a and outputs a data voltage or a first sensing driving voltage or a second sensing driving voltage, ) To the sample / hold circuit 221. The sample / The sample / hold circuit 221 may be included in the drive IC 120 of FIG. The sensing line SL may selectively receive the first initializing voltage VSPRE and the second initializing voltage VRPRE through the switch unit 202. [ Here, the voltage level of the second initializing voltage VRPRE may be the first reference voltage Vref1. The switch unit 202 includes a first switch S1 for selectively connecting to the sample / hold circuit 221 in response to the first switch signal, and a second switch for selectively selecting the first initialization voltage VSPRE And a third switch S3 for selecting the second initialization voltage VRPRE in response to the third switch signal. Here, the sample / hold circuit 221 is connected through the first switch S1 and can store the pixel voltage. 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 is possible to switch to a digital signal.

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

Referring to FIG. 3, the pixel 201 may be divided into a sensing driving period T11 and a sensing period T112. The sensing operation period T11 and the sensing period T2 may be separately operated by the controller 130 shown in FIG. The control unit 130 may terminate the sensing driving period T1 and enter the sensing period T2 when the temperature of the driving IC 120 reaches a preset temperature. In addition, when the sensing driving period T1 of the drive IC 120 is maintained for a preset period of time, it is possible to start the sensing period T2. However, the present invention is not limited thereto. 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. 1 It can be generated in the drive IC 120 by the control signal and supplied to the pixel. However, the present invention is not limited thereto. The first switch signal SAM, the second switch signal SPRE and the third switch signal RPRE may be supplied from the control unit 130 to the switch unit 202.

First, in the sensing driving period T11, the gate signal G and the sensing signal SS can be supplied in a low state. The first switch signal SAM, the second switch signal SPRE, and the third switch signal RPRE can be supplied in a low state. Then, the first sensing driving voltage Vdata1 may repeatedly indicate the low state and the high state. The first sensing driving voltage Vdata1 may repeatedly indicate a low state and a high state in response to a signal generated in the controller 130. [ However, the present invention is not limited thereto, and it is also possible to generate a signal in which the driver IC 120 itself repeats the low state and the high state without receiving the data signal from the controller 130. The first reference voltage Vref1 maintains the high state, and the voltage of the sensing line can be kept high. Further, the low potential voltage EVSS may be lower than the high potential voltage ELVDD. However, the low potential EVSS may be higher than the low state voltage 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.

Also, 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. Therefore, the voltage difference between the anode electrode and the cathode electrode of the organic light emitting diode is lower than the threshold voltage of the organic light emitting diode OLED in the sensing driving period T11, so that the organic light emitting diode OLED does not emit light.

The first sensing driving voltage Vdata1 supplied from the driving IC 120 may not be transmitted to the pixel circuit because the second transistor M2 is off when the gate signal is in a low state. In addition, if the sensing control signal SS is low, the sensing line and the pixel circuit may be in a short state because the third transistor M3 is off. 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, State can be maintained. At this time, the output buffer 223 of the drive IC operates, and the first sensing driving voltage Vdata1 may repeatedly exhibit 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, if it is determined that the temperature of the drive IC 120 has reached the predetermined temperature, it can enter the sensing period T21. The gate signal G and the sensing control signal SS can be in the high state and the high state can be maintained in the sensing period T2. The second sensing driving voltage Vdata2 may be supplied to the data line DL.

The second sensing driving voltage Vdata2 may be transferred to the first node N1 when the gate signal G is in the high state. When the sensing signal SS is in a high state, the third transistor M3 may be turned on. Further, when the gate signal G and the sensing signal SS are in a high state, the second switch signal SPRE becomes a high state and the second switch S2 can be turned on. The second switch signal may be in the low state in the sensing period T2 after maintaining the high state for a predetermined period. When the second switch S2 is turned on, the first initializing voltage VSPRE applied to the sensing line SL is transferred to discharge the first reference voltage Vref1 through the second switch S2. When the first reference voltage Vref1 is discharged, the voltage of the second node N2 may drop from the high state to the first initializing voltage VSPRE that is low.

The first transistor M1 can supply the driving current in the second node direction 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 rises. The slope at which the voltage of the second node N2 rises may correspond to the magnitude of the driving current. When the voltage of the second node N2 starts rising 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 turned on by the sensing line (SL). The sample / hold circuit 221 may store the pixel voltage, which is the voltage of the second node N2. In addition, the sample / hold circuit 221 can transmit the pixel voltage (the voltage of the second node N2) to the ADC (not shown) and generate the correction voltage at the ADC. The ADC can receive a plurality of pixel voltages and generate a correction voltage for each pixel.

Generally, when a pixel voltage is sensed and a correction voltage is generated in the ADC, a correction voltage deviation due to a temperature change may occur. However, if the pixel voltage is sensed after increasing the temperature of the drive IC in the sensing driving period, the temperature is sufficiently raised, and the temperature change may not occur when the ADC generates the correction voltage. As a result, the deviation of the correction voltage does not occur, and the image quality degradation due to the correction voltage deviation can be prevented from occurring. The temperature change can be detected using the temperature sensor 140 shown in FIG. 1, and it can be determined that predetermined temperature information is generated when the sensing driving period is maintained for a predetermined time (T1) or longer. Thus, even if the temperature sensor 140 is not provided, the operation can be performed in accordance with the temperature. Also, in case of using in a cold area, the sensing mode can be operated even if the temperature does not rise to a predetermined temperature.

Fig. 4 is a waveform diagram showing an embodiment of signals supplied to the pixels shown in odd-numbered columns and even-numbered columns of the display panel in Fig.

A plurality of pixels included in the display panel can be divided into at least a first group and a second group different from the first group. When the pixels of the first group are operated in accordance with the sensing period by the control unit, the pixels of the second group may operate corresponding to the sensing driving period, and the pixels of the first group may be operated corresponding to the sensing driving period. , The pixels of the second group can operate corresponding to the sensing period. The pixels of the first group are pixels arranged in an odd column of the display panel 110 shown in FIG. 1, and the pixels of the second group are pixels arranged in an even column of a display panel. Further, the odd-numbered columns and the even-numbered columns can be distinguished corresponding to the data lines. However, the present invention is not limited thereto.

Referring to FIG. 4, pixels arranged in an odd-numbered column in the first frame (1 frame) operate corresponding to a sensing period, and pixels arranged in an even-numbered column can operate corresponding to a sensing driving period. In the second frame (2 frame), the pixels arranged in the odd-numbered columns operate corresponding to the sensing driving period, and the pixels arranged in the even-numbered columns can operate corresponding to the sensing period.

First, in the first frame (1 frame), the gate signal and the sensing control signal are in a high state and can be kept in a high state for a certain period of time. The second switch signal SPRE_O connected to the odd-numbered sensing line maintains the 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. The second sensing driving voltage Vdata2 may be applied to the odd-numbered data lines.

The gate signal and the sensing control signal maintain a high state, and the second transistor connected to the odd-numbered data line and the third transistor connected to the odd-numbered sensing line are turned on. Then, the first reference voltage REF1_O applied to the odd-numbered sensing line may be discharged by the second switch signal SPRE_O, while the second switch signal SPRE_O is turned on. After the first reference voltage REF1_O is discharged, the pixel voltage corresponding to the magnitude of the current flowing from the first transistor of the pixel connected to the odd-numbered sensing line to the second sensing drive voltage Vdata2, So that the voltage level of the first reference voltage REF1_O can be raised. After the lapse of a predetermined time, the pixel voltage can be transferred to the sample / hold circuit connected to the odd-numbered sensing line by the first switch signal (SAM_O), so that it can operate in response to the sensing period.

The second switch signal SPRE_E connected to the even-numbered sensing line maintains the low state, and the third switch signal RPRE_E connected to the odd-numbered sensing line maintains the high state. As a result, the second initialization voltage Vinit2 can be transmitted to the even-numbered sensing lines, and the first reference voltage REF1_E can be applied to the even-numbered sensing lines. The first sensing driving voltage Vdata1 in which the high state and the low state are repeatedly appear may be applied to the data line. The gate signal G and the sensing control signal SS maintain the high state and are connected to the data lines of the even-numbered columns such as the pixel 201 shown in Fig. 2 and the sensing lines of the even-numbered columns, The transistor and the third transistor can be turned on. 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. However, the first reference voltage applied to the even- It may be applied to the anode electrode of the light emitting diode so that no driving current flows through the organic light emitting diode. By the first sensing driving voltage, the output buffer connected to the even-numbered data lines repeatedly outputs the high-state signal and the low-state signal to generate heat in the output buffer, thereby raising the temperature of the drive IC And can operate corresponding to the sensing driving period.

In the second frame, the pixels connected to the odd-numbered sensing lines operate corresponding to the sensing driving period, and the pixels connected to the even-numbered sensing lines operate corresponding to the sensing period. There is a possibility that the temperature is lowered when the sensing operation period is completed after the temperature is raised through the sensing driving period and the sensing period is performed. However, in this case, the sensing period and the sensing driving period may occur at the same time, .

5 is a structural view showing an embodiment of the drive IC shown in FIG.

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

The latch 521 receives the video signal RGB from the controller 130 shown in FIG. 1 and can output the data voltage in parallel. The data voltage output from the latch 521 may be a digital signal. The DAC 522 receives a data voltage output in parallel from the latch 521 and outputs the data voltage as an analog data voltage. The DAC 522 may output a first sensing driving voltage and a second sensing driving voltage in response to a signal received from the controller 130. [ Here, the first sensing driving voltage may be a signal for repeatedly outputting the data voltage corresponding to the first gradation and the data voltage corresponding to the second gradation. The first gradation corresponds to the highest gradation and the second gradation corresponds to the O gradation. However, the present invention is not limited to this, and the first sen drive voltage may be a voltage in which the high state voltage and the low state voltage repeatedly appear, and the high state voltage may be higher than the voltage corresponding to the highest gradation. The output buffer 523 can output the voltage output from the DAC 522 to the data lines D1, D2, ..., Dm-1, and Dm. When the data voltage corresponding to the first gradation and the data voltage corresponding to the second gradation are repeatedly output in the output buffer 523, heat may be generated and the temperature of the drive IC 520 may be increased.

Accordingly, there are pixels operating in the same interval corresponding to the sensing interval, and pixels operating corresponding to the sensing driving interval may exist.

6 is a structural view showing an embodiment of the drive IC shown in FIG.

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

The ADC 622 receives the pixel voltage VS from the sample / hold circuit 621 and receives the first voltage V1 in a high state and the 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. The correction voltage Va can be generated by applying the voltage of the pixel voltage VS using the first voltage V1 and the second voltage V2. The correction voltage Va can be output as a digital signal. At this time, the ADC 622 may vary the magnitude of the correction voltage Va output when the ambient temperature is normal or when the ambient temperature is high. If the magnitude of the correction voltage is different, the correction of the video signal may have a different value depending on the temperature, so that the correction of the video signal may not be accurately performed. Therefore, the ADC 622 calculates the correction voltage in a high temperature state, and outputs the magnitude of the correction voltage according to the characteristics of the pixel.

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

7, the controller 700 includes an operation unit 710 that receives the correction voltage Va and calculates a correction coefficient, a correction coefficient calculation unit 710 that receives the correction coefficients calculated by the image signal RGB and the operation unit 710, And a correcting unit 720 for outputting the RGB value RGBa.

The calculating unit 710 can calculate the correction coefficient G in accordance with the received correction voltage Va using a predetermined algorithm. Since the correction voltage Va is the voltage corresponding to the driving current flowing through the first transistor of the pixel, the characteristic of the first transistor can be grasped according to the magnitude of the correction voltage Va, The correction coefficient G may be generated for each pixel by using the correction voltage Va. The correction voltage Va stores a correction voltage Va calculated by the ADC 622 shown in Fig. 6 in a memory (not shown), and the calculation unit 710 calculates a correction voltage Va Va) can be used to calculate the correction coefficient G for each pixel.

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

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

Referring to FIG. 8, the driving method of the OLED display includes a sensing driving step (S800) for supplying a first sensing driving voltage, and a sensing control signal And sensing the pixel voltage applied to at least one of the plurality of pixels corresponding to the second sensing driving voltage (S810). In addition, the method may further include a correction step (S820) of correcting the image signal corresponding to the sensed pixel voltage.

The sensing driving step S800 is a step for raising the temperature of the drive IC. If the high signal and the low signal are repeated at the output terminal of the drive IC, the temperature of the drive IC may become high. To be more specific, when the high and low signals are repeatedly output from the output buffer of the drive IC, the output buffer may generate heat and the temperature of the drive IC may be increased. The drive IC can repeatedly output the high signal and the low signal in response to the first sensing driving voltage. The high signal may be a voltage corresponding to the first gradation and the low signal may be a voltage corresponding to the second gradation. Also, the first gradation may be the highest gradation and the second gradation may be the 0 gradation. However, the present invention is not limited thereto, and the high signal may be a voltage higher than the voltage corresponding to the highest gradation.

The sensing step S810 is a step in which it is started when it is determined that the temperature of the drive IC has become the predetermined temperature information. The predetermined temperature information may be information on a temperature higher than a predetermined temperature, and may be information on a time when the temperature does not rise any more and remains constant. The predetermined temperature information can be determined by measuring the temperature of the drive IC using a temperature sensor. Further, if the drive IC continues the sensing driving step for a predetermined time, it can be determined that the predetermined temperature has been reached, and it can be determined that predetermined temperature information is generated after the sensing driving step lasts for a predetermined time. The driving IC outputs the second sensing driving voltage and the generated pixel voltage corresponding to the output second sensing driving voltage to the drive IC.

In the correction step S820, the drive IC receiving the pixel voltage generates a correction voltage and transmits the correction voltage to the control unit, and the control unit can correct the image signal RGB using the received correction voltage. When the temperature is different when the correction voltage is generated, a deviation occurs in the correction voltage, and the image signal (RGB) is not accurately corrected due to such a deviation, resulting in a problem that the image quality is deteriorated. However, if a corrected voltage is generated in a state in which the temperature is sufficiently raised in the sensing driving step S800 when the correction voltage is generated in the drive IC, the deviation according to the temperature does not occur and the correction of the video signal RGB is made accurately Image quality degradation may not occur.

In addition, when the sensing operation 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 completed and the sensing step S810 is performed, the temperature of the driving IC may be lowered. If this temperature falls, there is a possibility of temperature deviation. Therefore, in order to solve this problem, when the temperature is sufficiently raised in the sensing driving step S800, the pixels arranged in the odd-numbered columns of the display panel perform the sensing driving step and the pixels arranged in the even- The pixels arranged in the odd-numbered columns of the display panel perform the sensing step, and the pixels arranged in the even-numbered columns perform the sensing driving step, thereby preventing the temperature of the driving IC from dropping in the sensing mode. Here, the description is made by dividing into odd numbers and even numbers, but the present invention is not limited thereto.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. , Separation, substitution, and alteration of the invention will be apparent to those skilled in the art. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, 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 construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: organic light emitting display
101: pixel
110: Display panel
120: Drive IC
130:
140: Temperature sensor
150:

Claims (15)

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 corresponding to the first sensing driving voltage and a second sensing driving voltage is supplied to the display panel by a sensing control signal A drive IC for receiving a pixel voltage corresponding to the second sensing driving voltage in the sensing period and corresponding to at least one pixel among the plurality of pixels in response to a sensing control signal; And
And a control unit for generating the correction voltage by receiving the pixel voltage from the drive IC by outputting the sensing control signal when the temperature of the drive IC rises and reaches a predetermined temperature, . The method according to claim 1,
The organic light emitting diode display of claim 1, further comprising a temperature sensor for sensing a temperature of the organic light emitting diode, wherein the control unit outputs the sensing control signal when the temperature sensor senses a predetermined temperature. The method according to claim 1,
Wherein the controller determines that the sensing driving period has reached a predetermined time after a predetermined time elapses and outputs the sensing control signal. The method according to claim 1,
The plurality of pixels are divided into at least a first group and a second group different from the first group,
If the first group is operated corresponding to the sensing period, the second group is operated corresponding to the sensing period, and when the first group is operated corresponding to the sensing period, Wherein the organic light emitting display device operates in response to the sensing driving period. The method according to claim 1,
The drive IC further includes an ADC, wherein the ADC compares the pixel voltage with a predetermined reference voltage to generate a correction voltage. 6. The method of claim 5,
Wherein the control unit further comprises: an operation unit that receives the correction voltage and calculates a correction coefficient; and a correction unit that performs a calculation corresponding to the correction coefficient to correct a video signal. The method according to claim 1,
The display panel is divided into a sensing mode and a normal mode,
Wherein at least one of the plurality of pixels is disposed between a second power supply line supplying a high potential voltage and a high potential voltage supplied via a first power supply line supplying a high potential voltage, Wherein a voltage level of the voltage is set to be higher in at least a sensing period of the sensing period and the sensing driving period than in the normal mode. The method according to claim 1,
Wherein the driver IC includes a latch for generating a data voltage corresponding to a video signal and an output buffer for outputting the data voltage,
Wherein the first sensing driving voltage is a voltage for causing the output buffer to alternately output a voltage in a high state and a voltage in a low state. A driving method of an organic light emitting display device which generates a sensing signal by providing a sensing driving voltage with a drive IC driving a display panel including a plurality of pixels,
A sensing driving step of supplying the first sensing driving voltage; And
Sensing a pixel voltage corresponding to a second sensing driving voltage and applied to at least one pixel among the plurality of pixels when the predetermined temperature information corresponding to the first sensing driving voltage is received and outputs a sensing control signal, And driving the organic light emitting display device. 10. The method of claim 9,
And the predetermined temperature information is generated by sensing the temperature of the drive IC. 10. The method of claim 9,
Wherein the pre-set temperature information determines that the pre-set temperature information has been reached after a predetermined time elapses from the sensing driving step. 10. The method of claim 9,
The plurality of pixels are divided into at least a first group and a second group different from the first group,
Wherein the second group is operated corresponding to the sensing step when the first group is operated corresponding to the sensing driving step. 10. The method of claim 9,
The display panel is divided into a sensing mode and a normal mode,
Wherein at least one of the plurality of pixels is disposed between a second power supply line supplying a high potential voltage and a high potential voltage supplied through a first power supply line supplying a high potential voltage, Wherein the voltage level of the voltage is set higher in at least the sensing period of the sensing driving period and the sensing period than in the normal mode. 10. The method of claim 9,
And a correction step of correcting a video signal corresponding to the sensing signal. 10. The method of claim 9,
Wherein the first sensing driving voltage alternately outputs a voltage of a high state and a voltage of a low state.

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