Organic light emitting display device

Abstract

An organic light emitting display device is provided. In an organic light emitting display device displaying an image in a first mode or a second mode, the organic light emitting display device includes a first scan driver supplying a first scan signal having a first voltage to first scan lines, a second scan driver supplying a second scan signal having a second voltage greater than the first voltage to second scan lines, and a pixel unit including pixels each coupled to a corresponding first scan line and a corresponding second scan line. When a first image displayed in the second mode is changed to a second image to be displayed in the second mode, the second image is displayed in the first mode during a predetermined portion of a period in which the second image is displayed, and the second image is displayed in the second mode during a remaining portion of the period.

Description

[0001] This application is a divisional application of Chinese patent application No. 201811105148.6, filed on September 21, 2018, entitled "Organic Light Emitting Display Device". Technical Field

[0002] The disclosed embodiments relate to an organic light-emitting display device. Background Technology

[0003] With the development of information technology, display devices, as the connection medium between users and information, have become increasingly important. Therefore, display devices such as liquid crystal displays (LCDs) and organic light-emitting diode (OLEDs) are widely used in various fields.

[0004] In such display devices, organic light-emitting diodes (OLEDs) are used to display images. OLEDs generate light through the recombination of electrons and holes. OLED displays feature high response times and are driven by low power consumption.

[0005] Recently, methods have been used to drive organic light-emitting display devices at low frequencies to minimize power consumption. Summary of the Invention

[0006] In a method for driving an organic light-emitting display device at a low frequency, it is desirable to improve the display quality when using the method to drive the organic light-emitting display device at a low frequency.

[0007] The embodiments of the invention provide an organic light-emitting display device with improved display quality.

[0008] According to a disclosed embodiment, an organic light-emitting display device displays an image using a first driving frequency in a first mode or using a second driving frequency lower than the first driving frequency in a second mode. The organic light-emitting display device includes: a first scan driver supplying a first scan signal having a first voltage to a first scan line; a second scan driver supplying a second scan signal having a second voltage greater than the first voltage to a second scan line; and a pixel unit including a plurality of pixels, each pixel coupled to a corresponding first scan line and a corresponding second scan line in the second scan line. In such an embodiment, when a first image displayed in the second mode is changed to a second image to be displayed in the second mode, the second image is displayed in the first mode during a predetermined portion of a time period in which the second image is displayed, and is also displayed in the second mode during the remaining portion of the time period.

[0009] In an embodiment, when the organic light-emitting display device is in a first mode, the first scan driver can repeatedly supply a first scan signal to each of the first scan lines during each first unit frame period corresponding to the first driving frequency, and the second scan driver can repeatedly supply a second scan signal to each of the second scan lines during each first unit frame period.

[0010] In an embodiment, when the organic light-emitting display device is in the second mode, the first scan driver can supply k (k is a natural number) first scan signals to each of the first scan lines during a second unit frame period corresponding to the second driving frequency, and the second scan driver can supply j (j is a natural number less than k) second scan signals to each of the second scan lines during the second unit frame period.

[0011] In an embodiment, the second unit frame time period may include a first time period and a second time period. When the organic light-emitting display device is in a second mode, the second scan driver may supply a second scan signal to the second scan line during the first time period.

[0012] In an embodiment, the first time period may be equal to the first unit frame time period.

[0013] In one embodiment, the second scan driver may not supply the second scan signal during the second time period.

[0014] In one embodiment, the organic light-emitting display device may further include a data driver that supplies data signals to data lines coupled to the pixels. In such an embodiment, the data driver may supply data signals to synchronize with a second scan signal.

[0015] In one embodiment, the data driver may supply the reference power supply voltage to the data line during a portion of the second unit frame period.

[0016] In an embodiment, the second time period may be longer than the first time period.

[0017] In an embodiment, a predetermined portion of the time period may be shorter than the remaining portion of the time period.

[0018] In an embodiment, a predetermined portion of the time period can be configured such that the first frame to the qth frame of the second image is displayed in a first mode, and the second image from the q+1th frame onwards is displayed in a second mode, wherein q can be a natural number of 2 or greater.

[0019] In an embodiment, a predetermined portion of the time period may be twice or more than the first unit frame time period.

[0020] In an embodiment, each pixel located on the i-th (i is a natural number) horizontal line may include: an organic light-emitting diode (OLED); and a pixel circuit coupled to the anode electrode of the OLED, wherein the pixel circuit controls the amount of current flowing through the OLED.

[0021] In an embodiment, when the organic light-emitting display device is in the second mode, the anode electrode of the organic light-emitting diode can be initialized k times to the voltage of the initialization power supply during the second unit frame time period.

[0022] In an embodiment, the pixel circuit may include: a first transistor that controls the amount of current flowing from a first power source coupled to a first electrode of the first transistor through an organic light-emitting diode to a second power source, wherein the amount of current corresponds to the voltage of a node coupled to the gate electrode of the first transistor; a second transistor coupled between a data line and the first electrode of the first transistor, wherein the second transistor is turned on when an i-th first scan signal is supplied to the second transistor; a third transistor coupled between the second electrode of the first transistor and a node, wherein the third transistor is turned on when an i-th second scan signal is supplied to the third transistor; and a fourth transistor coupled between a node and an initialization power source, wherein the fourth transistor is turned on when an (i-1)-th second scan signal is supplied to the fourth transistor.

[0023] In the embodiments, the first transistor and the second transistor can be P-type transistors, and the third transistor and the fourth transistor can be N-type oxide semiconductor transistors.

[0024] In an embodiment, the pixel circuit may further include: a fifth transistor coupled between the first power supply and the first transistor; a sixth transistor coupled between the first transistor and the organic light-emitting diode; and a seventh transistor coupled between the initialization power supply and the organic light-emitting diode.

[0025] In this embodiment, the fifth, sixth, and seventh transistors may be P-type transistors.

[0026] In an embodiment, the fifth and sixth transistors can be formed as P-type transistors, and the seventh transistor can be an N-type oxide semiconductor transistor.

[0027] In one embodiment, the organic light-emitting display device may further include: a third scan driver that supplies a third scan signal having a second voltage to a third scan line coupled to a pixel. In such an embodiment, when the i-th third scan signal is supplied to a seventh transistor, the seventh transistor can be turned on.

[0028] In an embodiment, when the organic light-emitting display device is in the second mode, the third scan driver can supply k third scan signals to each of the third scan lines during the second unit frame time period, where k is a natural number.

[0029] In one embodiment, the organic light-emitting display device may further include an emission driver that supplies emission control signals to emission control lines coupled to a plurality of pixels. In such an embodiment, the gate electrodes of the fifth, sixth, and seventh transistors may be coupled to the i-th emission control line.

[0030] According to another disclosed embodiment, an organic light-emitting display device is provided, which displays an image in a first mode using a first driving frequency or in a second mode using a second driving frequency lower than the first driving frequency. In such an embodiment, the organic light-emitting display device includes: pixels, each pixel including: an organic light-emitting diode; and pixel circuitry for controlling the amount of current flowing through the organic light-emitting diodes, wherein the pixel circuitry includes a plurality of P-type transistors and a plurality of N-type oxide semiconductor transistors. In such an embodiment, when the image displayed in the second mode is changed to another image to be displayed in the second mode, the other image is displayed in the first mode for a portion of the time period in which the other image is displayed, and in the second mode for the remainder of the time period.

[0031] In an embodiment, the organic light-emitting display device may further include: a first scan driver that supplies a first scan signal to at least some of the first scan lines coupled to a plurality of P-type transistors; a second scan driver that supplies a second scan signal to at least some of the second scan lines coupled to a plurality of N-type oxide semiconductor transistors; and a data driver that supplies a data signal to a data line coupled to a pixel.

[0032] In one embodiment, when the organic light-emitting display device is in the second mode, a frame time period may include a first time period and a second time period. In such an embodiment, when the organic light-emitting display device is in the second mode, the second scan driver may not supply a second scan signal during the second time period.

[0033] In one embodiment, when the organic light-emitting display device is in the second mode, the data driver supplies the voltage of the reference power supply to the data line during the second time period.

[0034] According to another disclosed embodiment, an organic light-emitting display device is provided, which displays an image in a first mode using a first driving frequency or in a second mode using a second driving frequency lower than the first driving frequency. In such an embodiment, the organic light-emitting display device includes: pixels coupled to a first scan line, a second scan line, and a data line; a first scan driver supplying a first scan signal to the first scan line; a second scan driver supplying a second scan signal to the second scan line; and a timing controller supplying an equal number of start pulses to the first and second scan drivers in the first mode, and a different number of start pulses to the first and second scan drivers in the second mode. In such an embodiment, when the image displayed in the second mode changes to another image to be displayed in the second mode, the other image is displayed in the first mode for a portion of the time period during which the other image is displayed, and is also displayed in the second mode for the remainder of the time period.

[0035] In an embodiment, when the organic light-emitting display device is in the second mode, the timing controller can supply h (h is a natural number of 2 or greater) start pulses to the first scan driver within a frame period, and the timing controller can supply p (p is a natural number less than h) start pulses to the second scan driver during a frame period.

[0036] In an embodiment, the portion of the time period may be shorter than the remainder of the time period.

[0037] In an embodiment, each of the pixels may include: an organic light-emitting diode; and a pixel circuit coupled to the anode electrode of the organic light-emitting diode, wherein the pixel circuit controls the amount of current flowing through the organic light-emitting diode, and the pixel circuit may include a plurality of P-type transistors and a plurality of N-type oxide semiconductor transistors. Attached Figure Description

[0038] The above and other features of the invention will become more apparent from the further detailed description of exemplary embodiments of the invention with reference to the accompanying drawings, in which:

[0039] Figure 1A This is a diagram schematically illustrating the construction of a display device according to a disclosed embodiment;

[0040] Figure 1B It is shown Figure 1A A diagram illustrating an embodiment of the pixels shown in the diagram;

[0041] Figure 2A It is a graph showing the gamma characteristics of a display device according to conventional technology;

[0042] Figure 2BIt is a graph showing the gamma characteristics of a display device according to a disclosed embodiment;

[0043] Figure 3 It is shown Figure 1B The signal timing diagram of an embodiment of the pixel driving method is shown in the figure;

[0044] Figure 4 and Figure 5 This shows the drive. Figure 1A The signal timing diagram of an embodiment of the method of an organic light-emitting display device is shown in the figure;

[0045] Figure 6A and Figure 6B This is a diagram illustrating the phenomenon that occurs when an image changes while an organic light-emitting display device is being driven at a second driving frequency;

[0046] Figure 7A and Figure 7B This shows the drive. Figure 1A A diagram illustrating an embodiment of a method for an organic light-emitting display device;

[0047] Figure 8 This is an example illustrating the supply to Figure 1A The diagram shows the waveforms of the start pulses of the first and second scan drivers.

[0048] Figure 9 It is shown Figure 1A A diagram showing alternative embodiments of the pixels;

[0049] Figure 10 It is shown Figure 9 The signal timing diagram of an embodiment of the pixel driving method is shown in the figure;

[0050] Figure 11 This is a diagram schematically illustrating the construction of a display device according to a disclosed alternative embodiment;

[0051] Figure 12 It is shown Figure 11 A diagram illustrating an embodiment of the pixels shown in the diagram;

[0052] Figure 13 It is shown Figure 12 The signal timing diagram of an embodiment of the pixel driving method shown in the figure; and

[0053] Figures 14 to 16 This shows the drive. Figure 11 The diagram shows a signal timing diagram of an embodiment of a method for an organic light-emitting display device. Detailed Implementation

[0054] The invention will now be described more fully below with reference to the accompanying drawings, in which various embodiments are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The same reference numerals throughout denote the same elements.

[0055] It will be understood that while the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or part from another. Therefore, without departing from the teaching herein, “first element,” “first component,” “first region,” “first layer,” or “first part” discussed below may be designated as a second element, second component, second region, second layer, or second part.

[0056] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a” and “the” are intended to include the plural forms containing “at least one”, unless the context clearly indicates otherwise. “Or” means “and / or”. As used herein, the term “and / or” includes any and all combinations of one or more of the related listed items. It will be further understood that when the terms “comprising” and / or variations thereof or “including” and / or variations thereof are used in this specification, it indicates the presence of the stated features, regions, integrals, steps, operations, elements, components, and / or groups thereof, but does not preclude the presence or addition of one or more other features, regions, integrals, steps, operations, elements, components, and / or groups thereof.

[0057] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms (such as those defined in a general dictionary) shall be interpreted as having the same meaning as they have in the relevant field and in the context of this disclosure, and shall not be interpreted in an idealized or overly formalized sense, unless expressly defined herein.

[0058] In the following description, embodiments of the organic light-emitting display device and its driving method will be described with reference to the accompanying drawings.

[0059] Figure 1AThis is a diagram schematically illustrating the construction of a display device according to a disclosed embodiment.

[0060] Reference Figure 1A An embodiment of an organic light-emitting display device may include a pixel unit 100, a first scan driver 210a, a second scan driver 210b, an emission driver 220, a data driver 230, a timing controller 250, and a host system 260.

[0061] In one embodiment, the host system 260 can supply image data RGB to the timing controller 250 through a predetermined interface. In such an embodiment, the host system 260 can supply timing signals Vsync, Hsync, DE, and CLK to the timing controller 250.

[0062] In this embodiment, the timing controller 250 can generate scan drive control signals SCS1 and SCS2, a data drive control signal DCS, and a transmit drive control signal ECS based on signals input from the host system 260. The scan drive control signals SCS1 and SCS2 generated by the timing controller 250 are supplied to scan drivers 210a and 210b, the data drive control signal DCS generated by the timing controller 250 is supplied to the data driver 230, and the transmit drive control signal ECS generated by the timing controller 250 is supplied to the transmit driver 220. In this embodiment, the timing controller 250 readjusts the RGB image data supplied externally and supplies the readjusted image data to the data driver 230.

[0063] The scan drive control signals SCS1 and SCS2 may include the clock signal CLK and the start pulses SSP1 and SSP2. Figure 8 (as shown in the image).

[0064] In one embodiment, the start pulses SSP1 and SSP2 may include a first start pulse SSP1 and a second start pulse SSP2. The first start pulse SSP1 may control the output timing of the first scan signal initially output from the first scan driver 210a. In such an embodiment, the second start pulse SSP2 may control the output timing of the second scan signal initially output from the second scan driver 210b. In another embodiment, the first start pulse SSP1 and the second start pulse SSP2 may be shifted in the first scan driver 210a and the second scan driver 210b respectively based on a clock signal.

[0065] The transmit drive control signal ECS may include a clock signal CLK and a start pulse.

[0066] The data-driven control signal (DCS) may include a source start pulse and a clock signal. In an embodiment, the sampling start time of data can be controlled in the transmit driver 220 based on the source start pulse, and the sampling operation can be controlled in the transmit driver 220 based on the clock signal.

[0067] The first scan driver 210a can supply a first scan signal to the first scan lines S11 to S1n in response to a first scan drive control signal SCS1. In one embodiment, for example, the first scan driver 210a can sequentially supply the first scan signal to the first scan lines S11 to S1n. When the first scan signal is sequentially supplied to the first scan lines S11 to S1n, pixels PXL can be selected in units of horizontal lines. In such an embodiment, the first scan signal can be set to have a gate on-state voltage (e.g., a voltage with a low potential (low level)) that turns on the transistors included in the pixel PXL.

[0068] The second scan driver 210b can supply a second scan signal to the second scan lines S21 to S2n in response to the second scan drive control signal SCS2. In one embodiment, for example, the second scan driver 210b can sequentially supply the second scan signal to the second scan lines S21 to S2n. The second scan signal can be set to a gate turn-on voltage (e.g., a voltage with a high potential (high level)) that turns on the transistors included in the pixel PXL.

[0069] In an embodiment, the organic light-emitting display device can be driven in a first mode or a second mode. In the first mode, the organic light-emitting display device is driven at a first driving frequency (e.g., a normal driving frequency), and in the second mode, the organic light-emitting display device is driven at a second driving frequency (e.g., a low driving frequency) lower than the first driving frequency. In one embodiment, for example, the first driving frequency may be 60 Hz or 120 Hz, and the second driving frequency may be 1 Hz.

[0070] The first scan driver 210a and the second scan driver 210b can selectively supply scan signals to scan lines S11 to S1n and S21 to S2n based on the drive frequency.

[0071] In one embodiment, for example, when driving an organic light-emitting display device in a first mode, for each predetermined time period, a first scan signal and a second scan signal can be repeatedly supplied to the first scan lines S11 to S1n and the second scan lines S21 to S2n, respectively.

[0072] When driving the organic light-emitting display device in the second mode, for each predetermined time period, the first scan signal can be repeatedly supplied to the first scan lines S11 to S1n, and the supply of the second scan signal to the second scan lines S21 to S2n can be stopped during the predetermined time period.

[0073] The data driver 230 can supply data signals to data lines D1 to Dm in response to a data drive control signal DCS. The data signals supplied to data lines D1 to Dm can be supplied to pixel PXL via a first scan signal. In such an embodiment, the data driver 230 can supply data signals to data lines D1 to Dm in synchronization with the first scan signal.

[0074] The emitter driver 220 can supply emitter control signals to emitter control lines E1 to En in response to an emitter drive control signal ECS. In one embodiment, for example, the emitter driver 220 can sequentially supply emitter control signals to emitter control lines E1 to En. In such an embodiment, when emitter control signals are sequentially supplied to emitter control lines E1 to En, pixel PXL does not emit light on a horizontal line basis. In such an embodiment, the emitter control signal can be set to a gate cutoff voltage (e.g., a voltage with a high potential (high level)) such that the transistors included in pixel PXL can be turned off.

[0075] In an embodiment, such as Figure 1A As shown, scan drivers 210a and 210b and transmit driver 220 may be separate components, but the disclosure is not limited thereto. In an alternative embodiment, for example, scan drivers 210a and 210b and transmit driver 220 may be included in a single driver.

[0076] In one embodiment, scan drivers 210a and 210b and / or emitter driver 220 may be mounted on a substrate using a thin-film process. In another embodiment, scan drivers 210a and 210b and / or emitter driver 220 may be located on either side of the pixel unit 100, with the pixel unit 100 inserted therebetween.

[0077] Pixel unit 100 may include a plurality of pixels PXL coupled (or connected) to data lines D1 to Dm, scan lines S11 to S1n and S21 to S2n and emission control lines E1 to En.

[0078] The pixel PXL can be supplied with an initialization power Vint, a first power ELVDD, and a second power ELVSS.

[0079] When a scan signal is supplied to scan lines S11 to S1n or S21 to S2n coupled to pixel PXL, each pixel PXL can be selected to be supplied with a data signal from data lines D1 to Dm. The pixel PXL supplied with a data signal can control the amount of current corresponding to the data signal flowing from the first power supply ELVDD through an organic light-emitting diode (not shown) to the second power supply ELVSS.

[0080] In one embodiment, the organic light-emitting diode (OLED) can generate light with a predetermined illuminance corresponding to the current. In such an embodiment, the first power supply ELVDD can be set to a voltage higher than that of the second power supply ELVSS.

[0081] In an embodiment, such as Figure 1A As shown, pixel PXL can be coupled to the first scan line S1i, the second scan line S2i, the data line Dj, and the transmit control line Ei, but the disclosure is not limited thereto. In alternative embodiments, the signal lines coupled to pixel PXL can be configured differently according to the circuit structure of pixel PXL.

[0082] Figure 1B It is shown Figure 1A The diagram shows an embodiment of the pixels. For ease of explanation and description, in... Figure 1B The image shows pixel PXL located on the i-th horizontal line and coupled to the j-th data line Dj.

[0083] Reference Figure 1B An embodiment of the pixel PXL may include an organic light-emitting diode (OLED) and a pixel circuit 310 for controlling the amount of current supplied to the OLED.

[0084] The anode electrode of the organic light-emitting diode (OLED) can be coupled to the pixel circuit 310, and the cathode electrode of the organic light-emitting diode (OLED) can be coupled to the second power supply ELVSS.

[0085] Organic light-emitting diodes (OLEDs) can produce light with a predetermined illuminance corresponding to the amount of current supplied from the pixel circuit 310.

[0086] The pixel circuit 310 can control the amount of current corresponding to the data signal flowing from the first power supply ELVDD through the organic light-emitting diode OLED to the second power supply ELVSS.

[0087] In an embodiment, such as Figure 1B As shown, the pixel circuit 310 may include a first transistor T1 to a seventh transistor T7 and a storage capacitor Cst.

[0088] The first transistor T1, the second transistor T2, and the fifth transistor T5 through the seventh transistor T7 can be P-type transistors. In one embodiment, for example, the first transistor T1, the second transistor T2, and the fifth transistor T5 through the seventh transistor T7 can be P-type polycrystalline silicon semiconductor transistors.

[0089] In one embodiment, the third transistor T3 and the fourth transistor T4 may be N-type transistors. In another embodiment, for example, the third transistor T3 and the fourth transistor T4 may be N-type oxide semiconductor transistors.

[0090] Oxide-semiconductor transistors (OSTs) can be formed using low-temperature processes and have a lower charge mobility than polycrystalline silicon (PCS) transistors. Therefore, OSTs exhibit high cutoff current characteristics. Consequently, in embodiments where the third transistor T3 and the fourth transistor T4 are formed as OSTs, leakage current from the first node N1 can be minimized, thereby improving the display quality of the organic light-emitting display device.

[0091] Figure 2A It is a graph showing the gamma characteristics of a display device (hereinafter referred to as a display device according to conventional technology) that is provided with pixels including polysilicon semiconductor transistors. Figure 2B This is a graph showing the gamma characteristics of a display device (hereinafter referred to as a display device according to the disclosed embodiment) that is provided with pixels including both polysilicon semiconductor transistors and oxide semiconductor transistors.

[0092] In particular, Figure 2A The diagram shows a first graph, a second graph, a third graph, and a fourth graph. The first graph shows the gamma characteristics when the display device according to conventional technology is driven at a driving frequency of 120 Hz. The second graph shows the gamma characteristics when the display device according to conventional technology is driven at a driving frequency of 60 Hz. The third graph shows the gamma characteristics when the display device according to conventional technology is driven at a driving frequency of 30 Hz. The fourth graph shows the gamma characteristics when the display device according to conventional technology is driven at a driving frequency of 15 Hz.

[0093] like Figure 2A As shown, the first through fourth graphs are all different from each other. Specifically, as... Figure 2A As shown, the curves at low gray levels exhibit large variations. Therefore, when the driving frequency of a display device based on conventional technology is changed, the user will perceive the change in driving frequency.

[0094] Figure 2BA fifth graph and a sixth graph are shown. The fifth graph shows the gamma characteristics when the display device according to the disclosed embodiment is driven at a driving frequency of 60 Hz, and the sixth graph shows the gamma characteristics when the display device according to the disclosed embodiment is driven at a driving frequency of 1 Hz.

[0095] like Figure 2B As shown, the fifth and sixth curves are essentially identical. Specifically, as... Figure 2B As shown, regardless of the driving frequency, the same gamma characteristics are displayed even at low gray levels.

[0096] Therefore, in embodiments where the pixel includes both polysilicon semiconductor transistors and oxide semiconductor transistors, changes in the user identification drive frequency are effectively prevented.

[0097] Return to reference Figure 1B In one embodiment, the seventh transistor T7 can be coupled between the initialization power supply Vint and the organic light-emitting diode (OLED). In such an embodiment, the gate electrode of the seventh transistor T7 can be coupled to the (i+1)th scan line S1(i+1). When the first scan signal is supplied to the (i+1)th scan line S1(i+1), the seventh transistor T7 can be turned on to supply the voltage of the initialization power supply Vint to the anode electrode of the OLED. Here, the initialization power supply Vint can have a voltage lower than the voltage of the data signal.

[0098] The sixth transistor T6 can be coupled between the first transistor T1 and the organic light-emitting diode (OLED). In such an embodiment, the gate electrode of the sixth transistor T6 can be coupled to the i-th emission control line Ei. When an emission control signal is supplied to the i-th emission control line Ei, the sixth transistor T6 can be turned on; otherwise, it can be turned off.

[0099] The fifth transistor T5 can be coupled between the first power supply ELVDD and the first transistor T1. In such an embodiment, the gate electrode of the fifth transistor T5 can be coupled to the i-th emitter control line Ei. When an emitter control signal is supplied to the i-th emitter control line Ei, the fifth transistor T5 can be turned on; otherwise, it can be turned off.

[0100] In one embodiment, the first electrode of the first transistor (e.g., a driving transistor) T1 can be coupled to the first power supply ELVDD via a fifth transistor T5, and the second electrode of the first transistor T1 can be coupled to the anode electrode of the organic light-emitting diode (OLED) via a sixth transistor T6. In such an embodiment, the gate electrode of the first transistor T1 can be coupled to a first node N1. The first transistor T1 can control the amount of current flowing from the first power supply ELVDD through the OLED to the second power supply ELVSS, corresponding to the voltage of the first node N1.

[0101] The third transistor T3 can be coupled between the second electrode of the first transistor T1 and the first node N1. In such an embodiment, the gate electrode of the third transistor T3 can be coupled to the i-th second scan line S2i. When a scan signal is supplied to the i-th second scan line S2i, the third transistor T3 can be turned on, so that the second electrode of the first transistor T1 and the first node N1 are electrically coupled to each other. Therefore, when the third transistor T3 is turned on, the first transistor T1 can be diode-coupled.

[0102] The fourth transistor T4 can be coupled between the second electrode of the first transistor T1 and the initialization power supply Vint. In such an embodiment, the gate electrode of the fourth transistor T4 can be coupled to the (i-1)th second scan line S2(i-1). When a scan signal is supplied to the (i-1)th second scan line S2(i-1), the fourth transistor T4 can be turned on to supply the voltage of the initialization power supply Vint to the first node N1.

[0103] The second transistor T2 can be coupled between the j-th data line Dj and the first electrode of the first transistor T1. In such an embodiment, the gate electrode of the second transistor T2 can be coupled to the i-th first scan line S1i. When a scan signal is supplied to the i-th first scan line S1i, the second transistor T2 can be turned on, which electrically couples the j-th data line Dj and the first electrode of the first transistor T1 to each other.

[0104] The storage capacitor Cst can be coupled between the first power supply ELVDD and the first node N1. The storage capacitor Cst can store the voltage corresponding to the data signal and the threshold voltage of the first transistor T1.

[0105] Figure 3 It is shown Figure 1B The diagram shows a signal timing diagram of an embodiment of the pixel driving method.

[0106] Reference Figure 3In one embodiment, the first scan signal can be set to a low potential (low level) voltage to turn on the first transistor T1, the second transistor T2, and the fifth transistors T5 through T7, which are P-type transistors. In such an embodiment, the second scan signal can be set to a high potential (high level) voltage to turn on the third transistor T3 and the fourth transistor T4, which are N-type transistors.

[0107] In such an embodiment, the transmit control signal Fi is supplied to the i-th transmit control line Ei. When the transmit control signal Fi is supplied to the i-th transmit control line Ei, the fifth transistor T5 and the sixth transistor T6 are turned off, so that the pixel PXL can be in a non-emitting state.

[0108] Subsequently, the second scan signal G2(i-1) is supplied to the (i-1)th second scan line S2(i-1). When the second scan signal G2(i-1) is supplied to the (i-1)th second scan line S2(i-1), the fourth transistor T4 is turned on. When the fourth transistor T4 is turned on, the voltage of the initialization power supply Vint is supplied to the first node N1, and the first node N1 can be initialized to the voltage of the initialization power supply Vint.

[0109] When the first node N1 is initialized to the voltage of the initial power supply Vint, the first scan signal G1i and the second scan signal G2i are supplied to the i-th first scan line S1i and the i-th second scan line S2i, respectively.

[0110] When the second scan signal G2i is supplied to the i-th second scan line S2i, the third transistor T3 is turned on. When the third transistor T3 is turned on, the first transistor T1 is diode coupled.

[0111] When the first scan signal G1i is supplied to the i-th first scan line S1i, the second transistor T2 is turned on. When the second transistor T2 is turned on, the data signal DS from the j-th data line Dj is supplied to the first electrode of the first transistor T1, and the first transistor T1 can be turned on because the first node N1 is initialized to the voltage of the initialization power supply Vint, which is lower than the voltage of the data signal. When the first transistor T1 is turned on, the data signal DS supplied to the first electrode of the first transistor T1 is supplied to the first node N1 via the diode-coupled first transistor T1, and the voltage obtained by subtracting the threshold voltage of the first transistor T1 from the data signal DS is applied to the first node N1.

[0112] When the voltage obtained by subtracting the threshold voltage of the first transistor T1 from the data signal DS is applied to the first node N1, the storage capacitor Cst stores the voltage applied to the first node N1.

[0113] Next, the first scan signal G1(i+1) is supplied to the (i+1)th first scan line S1(i+1), thus turning on the seventh transistor T7. With the seventh transistor T7 on, the voltage of the initialization power supply Vint is supplied to the anode electrode of the organic light-emitting diode (OLED). This discharges the parasitic capacitors formed parasitically in the OLED, thereby improving the black level performance of pixel PXL.

[0114] Subsequently, the supply of transmission control signal Fi to the i-th transmission control line Ei is stopped.

[0115] When the supply of the transmit control signal Fi to the i-th transmit control line Ei is stopped, the fifth transistor T5 and the sixth transistor T6 are turned on, and a current path is formed from the first power supply ELVDD through the fifth transistor T5, the first transistor T1, the sixth transistor T6 and the organic light-emitting diode OLED to the second power supply ELVSS.

[0116] When a current path is formed, the first transistor T1 controls the amount of current flowing from the first power supply ELVDD through the organic light-emitting diode (OLED) to the second power supply ELVSS, corresponding to the voltage of the first node N1. The OLED generates light with a predetermined illuminance corresponding to the amount of current supplied from the first transistor T1.

[0117] In this embodiment, each pixel PXL generates light with a predetermined illuminance while repeating the above operations.

[0118] The transmit control signal Fi supplied to the i-th transmit control line Ei can be superimposed with at least the i-th first scan signal G1i, such that pixel PXL is set to a non-transmitting state during the period when the data signal is filled into pixel PXL. This timing of the supply of the transmit control signal Fi can be changed in various ways.

[0119] Figure 4 This shows the driving method used in the first mode. Figure 1A The diagram shows a signal timing diagram of an embodiment of a method for an organic light-emitting display device.

[0120] In the following description, for ease of description, it is assumed that the first driving frequency is 60Hz. However, the disclosure is not limited to this, and alternatively, the first driving frequency may be 120Hz. In such embodiments, the first driving frequency may be set differently.

[0121] In one embodiment, the organic light-emitting display device is driven at a first driving frequency in a first mode, and at a second driving frequency lower than the first driving frequency in a second mode.

[0122] Reference Figure 4In the first mode, first scan signals G11 to G1n can be sequentially supplied during a first unit frame time period 1F, and simultaneously, second scan signals G1 to G2n can be sequentially supplied during the same period. In an embodiment, the first unit frame time period 1F can be repeated a predetermined number of times (e.g., 60 times) corresponding to the first drive frequency during a unit time period T (e.g., 1 second).

[0123] The first scan signals G11 to G1n can be repeatedly supplied during each first unit frame period 1F. The second scan signals G21 to G2n can also be repeatedly supplied during each first unit frame period 1F. In such an embodiment, as... Figure 4 As shown, the i-th first scan signal G1i can be superimposed with the i-th second scan signal G2i.

[0124] Transmit control signals F1 to Fn can be supplied sequentially during the first unit frame period 1F. Transmit control signals F1 to Fn can be supplied repeatedly during each first unit frame period 1F.

[0125] Data signals DS can be supplied to synchronize with the first scan signals G11 to G1n and the second scan signals G21 to G2n.

[0126] Then, as referred above Figure 1B and Figure 3 As described, the voltage corresponding to the data signal DS can be stored in each pixel PXL. Each pixel PXL generates light with a predetermined illuminance corresponding to the data signal DS, so that a predetermined image can be displayed in the pixel unit 100.

[0127] In the first mode, the data signal DS is stored in each pixel PXL whenever the first unit frame time period 1F passes.

[0128] Figure 5 This shows the driving method in the second mode. Figure 1A The diagram shows a signal timing diagram of an embodiment of a method for an organic light-emitting display device.

[0129] In the following text, for ease of description, it is assumed that the second driving frequency is 1 Hz. However, the disclosure is not limited to this, and the second driving frequency can be set to be less than the first driving frequency in various ways.

[0130] In addition, Figure 5 The image shown is a signal of an embodiment in which the same image is displayed in pixel unit 100 in a second mode.

[0131] Reference Figure 5The second unit frame time period 1F' may include the first time period P1 and the second time period P2. Here, the second unit frame time period 1F' may be repeated a predetermined number of times (e.g., once) corresponding to the second drive frequency during the unit time period T (e.g., 1 second).

[0132] The second time period P2 can be longer than the first time period P1. In one embodiment, for example, the first time period P1 can be set to be equal to the first unit frame time period 1F. In such an embodiment, the second time period P2 can be a time period in the second unit frame time period 1F' other than the first time period P1.

[0133] The second scan signals G21 to G2n can be supplied during the first time period P1. The second scan signals G21 to G2n can be not supplied during the second time period P2.

[0134] In the second mode, the first scan signals G11 to G1n and the second scan signals G21 to G2n can be supplied sequentially during the first time period P1.

[0135] Furthermore, during the first time period P1, transmission control signals F1 to Fn can be supplied sequentially, and data signals DS can be supplied to synchronize with the first scan signals G11 to G1n and the second scan signals G21 to G2n. Then, during the first time period P1, the voltage corresponding to the data signal DS is stored in each pixel PXL.

[0136] During the second time period P2, the first scan signals G11 to G1n are supplied sequentially, and can be repeatedly supplied at a predetermined frequency. Here, the predetermined frequency can be set to be equal to the frequency corresponding to the first time period P1.

[0137] However, the second scan signals G21 to G2n may not be supplied during the second time period P2.

[0138] Furthermore, during the second time period P2, transmit control signals F1 to Fn are supplied sequentially, and can be repeatedly supplied at a predetermined frequency. The voltage of the reference power supply Vref can be supplied to data lines D1 to Dm during the second time period P2.

[0139] Reference Figure 1B and 5 During the first time period P1, the voltage of the data signal DS is stored in each pixel PXL, and the first transistor T1 supplies a predetermined current to the organic light-emitting diode OLED corresponding to the difference between the voltage of the first power supply ELVDD and the voltage of the data signal DS applied to the first node N1.

[0140] Next, when the second time period P2 begins, the fifth transistor T5 and the sixth transistor T6 of each pixel PXL are cut off by transmitting control signals F1 to Fn, so that pixel PXL is in a non-emitting state.

[0141] Subsequently, the second transistor T2 and the seventh transistor T7 of each pixel PXL are sequentially turned on by the first scan signals G11 to G1n.

[0142] When the second transistor T2 is turned on, the voltage of the reference power supply Vref from the data line Dm is supplied to the first electrode of the first transistor T1. Next, when the seventh transistor T7 is turned on, the anode electrode of the organic light-emitting diode (OLED) is initialized to the voltage of the initialization power supply Vint.

[0143] Subsequently, control signals F1 to Fn are emitted from pixel PXL.

[0144] During the second time period P2, the process can be repeated, in which, after setting pixel PXL to a non-emitting state, the voltage of the reference power supply Vref is applied to the first electrode of the first transistor T1. After initializing the anode electrode of the organic light-emitting diode OLED to the voltage of the initialization power supply Vint, the organic light-emitting diode OLED emits light again.

[0145] In the second mode, such a process, including the first time period P1 and the second time period P2, can be repeated in the second unit frame time period 1F' while the same image is being displayed.

[0146] Figure 6A and 6B This is a diagram illustrating the phenomenon that occurs when an image is changed while an organic light-emitting display device is being driven at a second driving frequency.

[0147] Reference Figure 6A The image displayed by pixel unit 100 can be changed into another image in the second mode. Here, the image before the image change can be defined as the first image, and the image after the image change can be defined as the second image.

[0148] When the first image changes to the second image, due to the hysteresis characteristic of the driving transistor (i.e., the first transistor) T1 included in each pixel PXL, the first and second images overlap each other during two unit frame periods. Therefore, although it is only desired to display the second image in the organic light-emitting display device when the first image changes to the second image, an afterimage of the first image as the image before the image change is retained for a predetermined period of time.

[0149] In this embodiment, because the unit frame time period is long in the second mode, the afterimage of the first image is retained for several seconds and will be recognized by the user.

[0150] Figure 6B This is a graph showing the illuminance measured for each frame after an image displayed in an organic light-emitting display device changes from a grayscale image of "0" to a grayscale image of "32". For example... Figure 6B As shown, at the point in time when the image displayed in the organic light-emitting display device is changed, an image with the target illuminance is not displayed, and several frames (e.g., at least three or more frames) are required until the illuminance of the changed image after the image displayed in the organic light-emitting display device has been changed reaches the target illuminance.

[0151] Therefore, in an organic light-emitting display device, due to the characteristics of the driving transistors included in each pixel, an image with the desired illuminance is not displayed during the initial portion of the time period in which the image displayed in the organic light-emitting display device is changed. Specifically, the above phenomenon occurs when the organic light-emitting display device is driven at a low frequency.

[0152] In the disclosed embodiments, the organic light-emitting display device is driven in a first mode during a predetermined time period to prevent the above-mentioned phenomenon.

[0153] This will be referred to below. Figure 7A and Figure 7B To provide a more detailed description.

[0154] Figure 7A and Figure 7B This is a diagram illustrating an embodiment of a method for driving an organic light-emitting display device when the image displayed in a pixel unit changes in a second mode.

[0155] Reference Figure 7A The first image can be displayed in the second mode. While the first image is being displayed, as shown in the reference... Figure 5 The second scan signals G21 to G2n are supplied during the first time period P1 of the second unit frame time period 1F', and may not be supplied during the second time period P2 of the second unit frame time period 1F'.

[0156] In the second mode, when the image displayed in the organic light-emitting display device changes from a first image to a second image different from the first image, the driving mode of the organic light-emitting display device can be changed back to the first mode during a predetermined time period Ts. In an embodiment, the organic light-emitting display device can be driven at a first driving frequency during the predetermined time period Ts, and then the driving mode of the organic light-emitting display device can be changed back to the second mode.

[0157] In such an embodiment, as referenced Figure 4 As described, during a predetermined time period Ts, first scan signals G11 to G1n and second scan signals G21 to G2n are repeatedly supplied during each first unit frame time period 1F.

[0158] In such an embodiment, during a predetermined time period Ts, transmit control signals F1 to Fn may be repeatedly supplied during each first unit frame time period 1F, and data signals DS may be supplied to synchronize with the first scan signals G11 to G1n and the second scan signals G21 to G2n.

[0159] Then, as referenced Figure 1B and Figure 3 The description states that the voltage corresponding to the data signal DS is stored in each pixel PXL. That is, for each first unit frame time period 1F, the data signal DS is stored in each pixel PXL.

[0160] Each pixel PXL generates light with a predetermined illuminance corresponding to the data signal DS, so that a second image can be displayed in pixel unit 100.

[0161] After a predetermined time period Ts, the organic light-emitting display device can be driven again at a second driving frequency, so that a second image can be displayed in a second mode.

[0162] The time period for displaying the second image in the first mode can be set shorter than the time period for displaying the second image in the second mode.

[0163] The predetermined time period Ts can be set to correspond to multiple first unit frame time periods 1F. In an embodiment, as shown... Figure 7A As shown, the predetermined time period Ts can be set to correspond to two first unit frame time periods 1F, but the disclosure is not limited thereto.

[0164] Reference Figure 7B When the first image is changed to the second image in the second mode, the organic light-emitting display device can be driven at the first driving frequency during the initial part (predetermined time period Ts) of the entire time period of displaying the second image.

[0165] When the first image is changed to the second image during a predetermined time period Ts, the organic light-emitting display device can be set to drive the organic light-emitting display device in the first mode until the qth frame (where q is a natural number of 2 or greater), and drive the organic light-emitting display device in the second mode from the q+1th frame.

[0166] In such an embodiment, such as Figure 7BAs shown, when the first image is changed to the second image, the target illumination is achieved starting from the third frame. Therefore, a predetermined time period Ts can be set so that the first two initial frames after the image change are displayed in the first mode, and the first mode is switched to the second mode starting from the third frame.

[0167] In an embodiment, such as Figure 7B As shown, the predetermined time period Ts can be set to correspond to two first unit frame time periods 1F (i.e., 2F).

[0168] Therefore, in such an embodiment, the interval between the first and second frames in which the second image is displayed is narrowed, and the interval between the second and third frames is also narrowed.

[0169] In embodiments according to the prior art, such as Figure 6A As shown, the overlap time between the previous image and the current image can be approximately 2 seconds. In alternative embodiments, such as... Figure 7B As shown, the time it takes for the previous image to overlap with the current image can be approximately 33.2 milliseconds (ms).

[0170] Figure 8 This is an example illustrating the supply to Figure 1A The diagram shows the waveforms of the starting pulses of the first and second scan drivers.

[0171] In the first mode, scan signals with equal pulse counts are supplied to the first scan lines S11 to S1n and the second scan lines S21 to S2n, as follows: Figure 4 As shown. Therefore, as Figure 8 As shown, the number of first start pulses SSP1 supplied from the timing controller 250 to the first scan driver 210a and the number of second start pulses SSP2 supplied from the timing controller 250 to the second scan driver 210b can be set to be equal to each other.

[0172] In the second mode, the number of pulses of the scan signal supplied to the first scan lines S11 to S1n and the number of pulses of the scan signal supplied to the second scan lines S21 to S2n are different from each other, such as... Figure 5 As shown in the diagram. Therefore, in the second mode, the number of first start pulses SSP1 supplied from the timing controller 250 to the first scan driver 210a and the number of second start pulses SSP2 supplied from the timing controller 250 to the second scan driver 210b can be set to be different from each other.

[0173] In one embodiment, for example, in the second mode, h (h is a natural number of 2 or greater) first start pulses SSP1 can be supplied to the first scan driver 210a during a unit time period, and p (p is a natural number of less than h) second start pulses SSP2 can be supplied to the second scan driver 210b during a unit time period.

[0174] Figure 9 It is shown Figure 1B A diagram showing alternative embodiments of pixels is provided. Figure 10 This is a diagram. Figure 9 The diagram shows a signal timing diagram of an embodiment of the pixel driving method.

[0175] For ease of explanation and description, Figure 9 The image shows a pixel PXL located on the i-th horizontal line and coupled to the j-th data line Dj. Figure 9 The pixels shown, except for the seventh transistor T7, are similar to... Figure 1B The pixels shown are essentially the same. They have been used in the description above. Figure 1B The same reference numerals are used to denote the embodiments of pixels shown in the figures. Figure 9 The same or similar elements shown in the figure. Any repeated detailed descriptions will be omitted or simplified below.

[0176] Reference Figure 9 An embodiment of the pixel PXL may include an organic light-emitting diode (OLED) and a pixel circuit 320 for controlling the amount of current supplied to the OLED.

[0177] The pixel circuit 320 may include a first transistor T1 to a seventh transistor T7 and a storage capacitor Cst to control the amount of current supplied to the organic light-emitting diode OLED.

[0178] In such an embodiment, the seventh transistor T7 may be an N-type transistor. In one embodiment, for example, the seventh transistor T7 may be an N-type oxide semiconductor transistor.

[0179] In this embodiment, the gate electrode of the seventh transistor T7 can be coupled to the i-th emission control line Ei. Therefore, when the emission control signal is supplied to the i-th emission control line Ei, the pixel PXL is in a non-emission state because the fifth transistor T5 and the sixth transistor T6 are turned off. At the same time, the seventh transistor T7 is turned on, so the anode electrode of the organic light-emitting diode OLED is initialized to the voltage of the initialization power supply Vint.

[0180] Figure 9 The pixel circuit 320 shown can be configured to be, except that the seventh transistor T7 is an N-type transistor, and... Figure 1BThe pixel circuit 310 shown is the same.

[0181] In such an embodiment, except that supplying a signal with a high potential (or high level) voltage (e.g., a transmit control signal) to the seventh transistor T7 enables the seventh transistor T7 to be turned on, and the turn-on timing of the seventh transistor T7 precedes the turn-on timing of the fourth transistor T4, the driving method of the pixel circuit 320 is the same as... Figure 1B The driving method of the pixel circuit 310 is basically the same.

[0182] Figure 11 This is a diagram schematically illustrating the construction of a display device according to a disclosed alternative embodiment. Figure 11 The diagram in the image, except for the third scan driver 210c, is related to... Figure 1A The diagram shown is essentially the same. It has already been used as described above. Figure 1A The same reference numerals are used to denote the embodiments of the display device shown in the figure. Figure 11 Any identical or similar elements shown herein will be omitted or simplified in their detailed description below.

[0183] Reference Figure 11 Embodiments of the organic light-emitting display device may further include a third scan driver 210c.

[0184] The timing controller 250 can generate a third scan drive control signal SCS3 based on the signal input from the host system 260. The third scan drive control signal SCS3 generated by the timing controller 250 can be supplied to the third scan driver 210c.

[0185] The third scan drive control signal SCS3 may include the clock signal CLK and the third start pulse.

[0186] The third start pulse can control the initial output timing of the third scan signal from the third scan driver 210c.

[0187] The third scan driver 210c can supply a third scan signal to the third scan lines S31 to S3n in response to the third scan drive control signal SCS3. In one embodiment, for example, the third scan driver 210c can sequentially supply the third scan signal to the third scan lines S31 to S3n.

[0188] The third scan signal can be set to a gate turn-on voltage (e.g., a high potential or high level voltage) so that the transistors (e.g., N-type transistors) included in the pixel PXL can be turned on.

[0189] In the first and second modes, the third scan driver 210c can repeatedly supply the third scan signal to the third scan lines S31 to S3n for each predetermined time period.

[0190] Figure 11 The organic light-emitting display device shown herein, in addition to providing a third scan driver 210c, is compatible with... Figure 1A The organic light-emitting display devices shown are basically the same.

[0191] Figure 12 It is shown Figure 11 A diagram showing an embodiment of the pixels. Figure 13 It is shown Figure 12 The diagram shows a signal timing diagram of an embodiment of the pixel driving method.

[0192] For ease of explanation and description, Figure 12 The image shows pixel PXL located on the i-th horizontal line and coupled to the j-th data line Dj. For ease of description, pixels PXL will be omitted or simplified. Figure 12 The above reference Figure 1B Any repeated detailed descriptions of the same or similar elements.

[0193] Reference Figure 12 An embodiment of the pixel PXL may include an organic light-emitting diode (OLED) and a pixel circuit 330 for controlling the amount of current supplied to the OLED.

[0194] The pixel circuit 330 may include a first transistor T1 to a seventh transistor T7 and a storage capacitor Cst to control the amount of current supplied to the organic light-emitting diode OLED.

[0195] The seventh transistor T7 can be an N-type transistor. In one embodiment, for example, the seventh transistor T7 can be an N-type oxide semiconductor transistor. In such an embodiment, the gate electrode of the seventh transistor T7 can be coupled to the i-th third scan line S3i.

[0196] Figure 12 The pixel circuit 330 shown in the diagram, except that the seventh transistor T7 is an N-type transistor, can be used with... Figure 1B The pixel circuit 310 shown is basically the same.

[0197] In such an embodiment, the driving method of the pixel circuit 330, in addition to supplying a signal with a high potential (or high level) voltage (e.g., a transmit control signal) to the seventh transistor T7 to enable the seventh transistor T7 to conduct, is also... Figure 1B The driving method of the pixel circuit 310 is basically the same.

[0198] Figure 14 This shows the driving method used in the first mode. Figure 11 The diagram shows a signal timing diagram of an embodiment of a method for an organic light-emitting display device.

[0199] Figure 14 The signal timing diagram in the image, excluding the third scan signals G31 to G3n, is related to... Figure 4 The signal timing diagrams shown are basically the same. They have already been used to describe the above. Figure 4 The same reference numerals are used to denote embodiments of the method for driving an organic light-emitting display device shown in the figure. Figure 14 Any identical or similar elements shown below will be omitted or simplified in their detailed descriptions.

[0200] Reference Figure 14 In the first mode, during the first unit frame time period 1F, the first scan signals G11 to G1n can be supplied sequentially, the second scan signals G21 to G2n can be supplied sequentially, and the third scan signals G31 to G3n can be supplied sequentially.

[0201] The first scan signals G11 to G1n, the second scan signals G21 to G2n, and the third scan signals G31 to G3n can be repeatedly supplied during each first unit frame time period 1F.

[0202] The first scan signals G11 to G1n supplied to the gate electrode of the P-type transistor can be set to a low potential (or low level) voltage. In such an embodiment, the second scan signals G21 to G2n and the third scan signals G31 to G3n supplied to the N-type transistor can be set to a high potential (or high level) voltage.

[0203] Here, the i-th third scan signal G3i can be superimposed with the i+1-th first scan signal G1(i+1) and the i+1-th second scan signal G2(i+1).

[0204] Transmit control signals F1 to Fn can be supplied sequentially during the first unit frame period 1F. Transmit control signals F1 to Fn can be supplied repeatedly during each first unit frame period 1F.

[0205] A data signal DS can be supplied to synchronize with the first scan signals G11 to G1n and the second scan signals G21 to G2n. Then, the voltage corresponding to the data signal DS is stored in pixel PXL. That is, the data signal DS is stored in pixel PXL for each unit frame period.

[0206] Each pixel PXL generates light with a predetermined illuminance corresponding to the data signal DS, so that a predetermined image can be displayed in the pixel unit 100.

[0207] Figure 15This shows the driving method in the second mode. Figure 11 The diagram shows a signal timing diagram of an embodiment of a method for an organic light-emitting display device.

[0208] Figure 15 The signal timing diagram in the image, excluding the third scan signals G31 to G3n, is related to... Figure 5 The signal timing diagrams shown are basically the same. They have already been used to describe the above. Figure 5 The same reference numerals are used to denote embodiments of the method for driving an organic light-emitting display device shown in the figure. Figure 15 Any identical or similar elements shown below will be omitted or simplified in their detailed descriptions.

[0209] Reference Figure 15 The second unit frame time period 1F' can include the first time period P1 and the second time period P2.

[0210] During the first time period P1, the first scan signals G11 to G1n can be supplied sequentially, the second scan signals G21 to G2n can be supplied sequentially, and the third scan signals G31 to G3n can be supplied sequentially.

[0211] In such an embodiment, during the first time period P1, transmission control signals F1 to Fn can be supplied sequentially, and data signals DS can be supplied to synchronize with the first scan signals G11 to G1n and the first scan signals G21 to G2n.

[0212] During the second time period P2, the first scan signals G11 to G1n can be supplied sequentially, and the third scan signals G31 to G3n can be supplied sequentially. Here, the first scan signals G11 to G1n and the third scan signals G31 to G3n can be supplied repeatedly during each first unit frame time period 1F.

[0213] During the second time period P2, the second scan signals G21 to G2n may not be supplied.

[0214] In addition, during the second time period P2, the transmit control signals F1 to Fn can be repeatedly supplied during the predetermined time period, and the voltage of the reference power supply Vref can be supplied to the data lines D1 to Dm.

[0215] When the same image is being displayed in the second mode, the second unit frame time period 1F', which includes the first time period P1 and the second time period P2, can be repeated.

[0216] Figure 16 This is a signal timing diagram illustrating an embodiment of a method for driving an organic light-emitting diode when the image displayed in a pixel unit is changed in a second mode.

[0217] Figure 16 The signal timing diagram in the image, excluding the third scan signals G31 to G3n, is related to... Figure 7A The signal timing diagrams shown are basically the same. They have already been used to describe the above. Figure 7A The same reference numerals are used to denote embodiments of the method for driving an organic light-emitting display device shown in the figure. Figure 16 Any identical or similar elements shown below will be omitted or simplified in their detailed descriptions.

[0218] Reference Figure 16 The first image can be displayed in the second mode.

[0219] Subsequently, the first image can be changed to a second image. In such an embodiment, the organic light-emitting display device can be driven at a first driving frequency during the initial portion of the time period in which the second image is displayed. The organic light-emitting display device can be driven at a second driving frequency during the remaining portion of the time period.

[0220] In such an embodiment, the second image may be displayed in the first mode for a portion of the time period and in the second mode for the remainder of the time period.

[0221] During this portion of the time period, the first scan signals G11 to G1n, the second scan signals G21 to G2n, and the third scan signals G31 to G3n can be repeatedly supplied during each first unit frame time period 1F.

[0222] Subsequently, the organic light-emitting display device can be driven again at the second driving frequency. In other words, a second image can be displayed in the second mode.

[0223] According to the disclosed embodiments, the organic light-emitting display device can have improved display quality.

[0224] The invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art.

[0225] Although the invention has been specifically shown and described with reference to exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit or scope of the invention as defined in the claims.

Claims

1. An organic light-emitting display device, wherein the organic light-emitting display device displays an image at a first driving frequency in a first mode or at a second driving frequency lower than the first driving frequency in a second mode, the organic light-emitting display device comprising: A pixel unit, comprising pixels, for displaying the image in the first mode or in the second mode; as well as The first scan driver and the second scan driver supply a first scan signal and a second scan signal to the pixel through scan lines, respectively. In the first mode, the number of pulses in the first scan signal and the second scan signal are the same, while in the second mode, the number of pulses in the first scan signal and the second scan signal are different. In this case, the first image in the second mode is changed to the second image in the second mode, and The second image is displayed at the first driving frequency during a predetermined time period, and at the second driving frequency after the predetermined time period.

2. The organic light-emitting display device as described in claim 1, wherein The predetermined time period is the initial portion of the entire display period of the second image. During the remainder of the entire display period of the second image, the second image is displayed at the second driving frequency, and In the second mode, the image including the second image is a static image.

3. The organic light-emitting display device as described in claim 1, wherein, When the organic light-emitting display device displays an image at the first driving frequency, the first scan driver repeatedly supplies the first scan signal to each of the first scan lines during each first unit frame period corresponding to the first driving frequency, and When the organic light-emitting display device displays the image at the first driving frequency, the second scan driver repeatedly supplies the second scan signal to each of the second scan lines during each first unit frame period.

4. The organic light-emitting display device as described in claim 3, wherein, When the organic light-emitting display device displays an image at the second driving frequency, the first scan driver supplies k first scan signals to each of the first scan lines during a second unit frame period corresponding to the second driving frequency, where k is a natural number, and When the organic light-emitting display device displays the image at the second driving frequency, the second scan driver supplies j second scan signals to each of the second scan lines during the second unit frame period, where j is a natural number less than k.

5. The organic light-emitting display device as described in claim 4, wherein, The second unit frame time period includes the first time period and the second time period. When the organic light-emitting display device displays the image at the second driving frequency, the second scan driver supplies the second scan signal to the second scan line during the first time period.

6. The organic light emitting display device of claim 5, wherein, The first time period is equal to the first unit frame time period.

7. The organic light emitting display device of claim 5, wherein the first and second electrodes are formed of a material having a work function of 2.0 eV or more. The second scan driver does not supply the second scan signal during the second time period.

8. The organic light-emitting display device as claimed in claim 5, further comprising: The data driver supplies data signals to the data lines coupled to the pixel. The data driver supplies the data signal to synchronize with the second scan signal.

9. The organic light emitting display device of claim 8, wherein, During a portion of the second unit frame period, the data driver supplies a reference power supply voltage to the data line.

10. The organic light emitting display device of claim 5, wherein, The second time period is longer than the first time period.

11. The organic light emitting display device of claim 1, wherein, The first scan signal has a first voltage, and the second scan signal has a second voltage that is different from the first voltage.

12. The organic light emitting display device of claim 11, wherein, Each of the pixels located on the i-th horizontal line includes: Organic light-emitting diodes; and The pixel circuit is coupled to the anode electrode of the organic light-emitting diode. in, The pixel circuit controls the amount of current flowing through the organic light-emitting diode, and i is a natural number.

13. The organic light emitting display device of claim 12, wherein, The pixel circuit includes: The first transistor controls the amount of current flowing from a first power source coupled to a first electrode of the first transistor through the organic light-emitting diode to a second power source, wherein the amount of current corresponds to the voltage of a node coupled to the gate electrode of the first transistor. The second transistor is coupled between the data line and the first electrode of the first transistor, wherein the second transistor is turned on when the i-th first scan signal is supplied to the second transistor; A third transistor is coupled between the second electrode of the first transistor and the node, wherein the third transistor is turned on when the i-th second scan signal is supplied to the third transistor; A fourth transistor is coupled between the node and the initialization power supply, wherein the fourth transistor is turned on when the (i-1)th second scan signal is supplied to the fourth transistor.

14. The organic light-emitting display device as claimed in claim 13, wherein, The first transistor and the second transistor are P-type transistors, and The third transistor and the fourth transistor are N-type oxide semiconductor transistors.

15. The organic light emitting display device of claim 14, wherein, The pixel circuit also includes: The fifth transistor is coupled between the first power supply and the first transistor; A sixth transistor is coupled between the first transistor and the organic light-emitting diode; and The seventh transistor is coupled between the initialization power supply and the organic light-emitting diode.

16. The organic light emitting display device of claim 15, wherein, The fifth transistor, the sixth transistor, and the seventh transistor are P-type transistors.

17. The organic light-emitting display device as claimed in claim 15, wherein, The fifth and sixth transistors are P-type transistors, and The seventh transistor is an N-type oxide semiconductor transistor.

18. A method for driving an organic light-emitting display device, the organic light-emitting display device displaying an image at a first driving frequency or at a second driving frequency lower than the first driving frequency, the method comprising: The first static image is displayed at the second driving frequency; The first static image is changed to a second static image, and the second static image is displayed at the first driving frequency during a predetermined time period; as well as Immediately after the predetermined time period, the second still image is displayed at the second driving frequency. wherein the second still image is displayed in a first mode during the predetermined period, and the second still image is displayed in a second mode after the predetermined period, wherein the organic light emitting display device comprises first and second scan drivers that supply first and second scan signals to pixels through scan lines, respectively, and wherein the number of pulses of the first and second scan signals is the same as each other in the first mode, and the number of pulses of the first and second scan signals is different from each other in the second mode.

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