Display device

Abstract

A display device is provided. The display device includes a pixel, a scan driver configured to supply a scan signal to the pixel through a scan line, an emission driver configured to supply an emission control signal including a plurality of gate-on level signals for generating a plurality of emission periods of the pixel to the pixel through an emission control line in one frame, a data driver configured to supply a data signal to the pixel through a data line, and a controller configured to control a waveform of the emission control signal, wherein a length of a first emission period among the plurality of emission periods is longer than a length of another emission period among the plurality of emission periods.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0095355, filed on July 30, 2020, which is incorporated herein by reference for all purposes, as if fully set forth herein. Technical Field

[0003] Exemplary implementations of the present invention generally relate to display devices, and more specifically, to display devices that operate in multiple transmission periods within a frame. Background Technology

[0004] The display device uses pixels that emit various colors of light (e.g., red, green, and blue light) to display images. The display device can control the display brightness through pulse dimming operation by adjusting the supply period (e.g., frequency or quantity) of the emission control signal.

[0005] However, during a pulse dimming operation in a frame that includes multiple emission periods, when the emission time for current to flow to each of the light-emitting elements is shortened after data is written to the pixel, color slippage and color smudging may be visually identifiable due to the difference in efficiency between the light-emitting elements that emit red, green, and blue light respectively.

[0006] The information disclosed in this background section is only for understanding the background of the concept of the present invention, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0007] The applicant discovered that when the display device displays moving or still images, image flickering and color bleeding are visually perceptible to the user.

[0008] A display device constructed according to the principles and implementation of the present invention, which operates in multiple emission periods within a frame, provides improved image quality. For example, when the display device operates in multiple emission periods, image flicker and color bleeding or bleeding of both moving and still images can be minimized or prevented, thereby improving image quality.

[0009] According to an aspect of the present application, a display device includes a pixel, a scan driver configured to supply a scan signal to the pixel through a scan line, a emission driver configured to supply an emission control signal including a plurality of gate-on level signals for generating a plurality of emission periods of the pixel to the pixel through an emission control line in one frame, a data driver configured to supply a data signal to the pixel through a data line, and a controller configured to control a waveform of the emission control signal, wherein a length of a first emission period of the plurality of emission periods is longer than a length of another emission period of the plurality of emission periods.

[0010] The plurality of non-emission periods of the pixel can be generated by a plurality of gate-off level signals of the emission control signal, and lengths of the plurality of non-emission periods can be the same in one frame.

[0011] The lengths of the plurality of emission periods can respectively correspond to widths of the plurality of gate-on level signals of the emission control signal.

[0012] The lengths of the remaining emission periods of the plurality of emission periods except for the first emission period can be the same.

[0013] In one frame, a length of a second emission period of the plurality of emission periods can be longer than a length of a third emission period of the plurality of emission periods.

[0014] The controller is configured to analyze a change in image data to select one of a motion image mode and a still image mode, and to adjust the lengths of the emission periods according to a motion image frame of the motion image mode or a still image frame of the still image mode.

[0015] The length of the first emission period of the motion image frame can be longer than the length of the first emission period of the still image frame, and the length of the second emission period of the motion image frame can be shorter than the length of the second emission period of the still image frame.

[0016] In the motion image mode, the controller can be configured to control the lengths of the emission periods of the motion image frame based on a display brightness.

[0017] The length of the first emission period corresponding to a first display brightness can be longer than the length of the first emission period corresponding to a second display brightness greater than the first display brightness.

[0018] In the motion image mode, the controller can be configured to control the lengths of the emission periods of the motion image frame based on an ambient temperature of the display device.

[0019] Under the condition of the same display brightness, the length of the first emission period corresponding to a first temperature can be longer than the length of the first emission period corresponding to a second temperature greater than the first temperature.

[0020] According to another aspect of the present application, a display apparatus includes a pixel, a scan driver configured to supply a scan signal to the pixel through a scan line, an emission driver configured to supply an emission control signal including a plurality of gate-on level signals for generating a plurality of emission periods of the pixel to the pixel through an emission control line, a data driver configured to supply a data signal to the pixel through a data line, and a controller configured to control a number of the emission periods during one frame based on image data variation and a display brightness.

[0021] The controller can be configured to gradually increase the number of the emission periods to a target number of the emission periods as a plurality of frames elapses.

[0022] The number of the emission periods of a second frame among the plurality of frames can be greater than the number of the emission periods of a first frame among the plurality of frames.

[0023] The number of the emission periods of the first frame corresponding to a first display brightness can be less than the number of the emission periods of the first frame corresponding to a second display brightness greater than the first display brightness, and the number of the emission periods of a k-th frame corresponding to the first display brightness and the number of the emission periods of the k-th frame corresponding to the second display brightness can be the same, where k is an integer greater than 3.

[0024] The controller can be configured to analyze the image data variation to select one of a still image mode and a moving image mode, when the still image mode starts, the controller can be configured to gradually increase the number of the emission periods to a target number of the emission periods as a plurality of frames elapses, and the number of the emission periods of a k-th frame of the still image mode can be greater than the number of the emission periods of the k-th frame of the moving image mode.

[0025] The controller can be configured to control the variation of the emission periods based on also an ambient temperature of the display apparatus, and the number of the plurality of frames required to increase the number of the emission periods to the target number of the emission periods corresponding to a first temperature can be greater than the number of the plurality of frames required to increase the number of the emission periods to the target number of the emission periods corresponding to a second temperature greater than the first temperature, under a condition of the same display brightness.

[0026] According to another aspect of the present application, a display apparatus includes a pixel, a scan driver configured to supply a scan signal to the pixel through a scan line, a emission driver configured to supply an emission control signal including a plurality of gate-on level signals for generating a plurality of emission periods and a plurality of emission cycles of the pixel to the pixel through an emission control line, a data driver configured to supply a data signal to the pixel through a data line, and a controller configured to control a length of the emission period and a number of the emission cycles during one frame based on a change in image data and a display brightness.

[0027] In the moving image frames of the moving image mode, a length of a first emission period of the plurality of emission periods can be longer than a length of another emission period of the plurality of emission periods, and wherein, in the moving image mode, the length of the first emission period corresponding to a first display brightness can be longer than the length of the first emission period corresponding to a second display brightness greater than the first display brightness.

[0028] In the still image mode, the number of the emission cycles can gradually increase to become a target number of the emission cycles as a plurality of frames elapses, in the still image mode, the number of the emission cycles of a first frame of the plurality of frames corresponding to a first display brightness can be smaller than the number of the emission cycles of the first frame corresponding to a second display brightness greater than the first display brightness, and the number of the emission cycles of a k-th frame corresponding to the first display brightness and the number of the emission cycles of the k-th frame corresponding to the second display brightness can be the same, where k is an integer greater than 3.

[0029] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the application as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application.

[0031] Figure 1 is a block diagram of an embodiment of a display apparatus constructed in accordance with the principles of the present application.

[0032] Figure 2 is Figure 1 a circuit diagram of an example of a representative pixel of the display apparatus of

[0033] Figure 3A and Figure 3B is a timing chart showing examples of signals supplied to the pixel of Figure 2

[0034] Figure 4 ​is a timing chart showing a change in current of a light emitting element of a pixel of a display device Figure 1

[0035] Figure 5 is a timing chart showing an example of a method of driving a display device Figure 1

[0036] Figure 6 is a timing chart showing another example of a method of driving a display device Figure 1

[0037] Figure 7 is a block diagram of an example of a controller and an emission driver of a display device Figure 1

[0038] Figure 8A Figure 8B Figure 8C are timing charts showing examples of emission control signals output in accordance with display luminance

[0039] Figure 9A Figure 9B Figure 9C are timing charts showing examples of emission control signals output in accordance with an ambient temperature

[0040] Figure 10 is a timing chart showing an example of an emission control signal output in a still image mode

[0041] Figure 11 is a timing chart showing another example of an emission control signal output in a still image mode

[0042] Figure 12A Figure 12B are timing charts showing examples of emission control signals output in accordance with display luminance in a moving image mode

[0043] Figure 13A Figure 13B are timing charts showing examples of emission control signals output in accordance with an ambient temperature in a still image mode DETAILED DESCRIPTION

[0044] ​​​​​​​​​​In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various embodiments or implementations of the present invention. As used herein, "embodiment" and "implementation" are interchangeable words that refer to a non-limiting example of an apparatus or method that employs one or more of the inventive concepts disclosed herein. It will be evident, however, that various embodiments can be practiced without these specific details, or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the various embodiments. Additionally, various embodiments can be different but not necessarily exclusive. For example, specific shapes, configurations, and features of an embodiment can be used or implemented in another embodiment without departing from the inventive concept.

[0045] Unless otherwise indicated, the embodiments shown will be understood to provide features of varying detail of some ways in which the inventive concept can be implemented in practice. Thus, unless otherwise indicated, features, components, modules, layers, films, panels, regions, and / or aspects of various embodiments (hereinafter, individually or collectively referred to as "elements") can be combined, separated, interchanged, and / or rearranged without departing from the inventive concept.

[0046] The use of cross-hatching and / or shading in the drawings is generally provided to illustrate the boundaries, of the elements shown. As such, unless otherwise specified, the presence of

[0047] When an element or layer is referred to as being “on,” “connected to,” or “linked to” another element or layer, the element or layer may be directly on, directly connected to, or directly linked to the other element or layer, or an intermediary element or layer may be present. However, when an element or layer is referred to as being “directly” on, directly connected to, or directly linked to another element or layer, an intermediary element or layer is not present. Therefore, the term “connection” may indicate a physical, electrical, and / or fluid connection, with or without an intermediary element. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be interpreted as X only, Y only, Z only, or any combination of two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0048] Although the terms “first,” “second,” etc., may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Therefore, without departing from the teachings of this disclosure, the first element discussed below may be referred to as the second element.

[0049] Spatial relative terms, such as “beneath,” “below,” “under,” “lower,” “above,” “upper,” “over,” “higher,” and “side” (e.g., as in “sidewall”), may be used herein for descriptive purposes and thus to describe the relationship of one element to another(s) as shown in the figures. Spatial relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture other than those depicted in the figures. For example, if the device in the figures is flipped, an element described as “below” or “below” other elements or features will subsequently be oriented “above” other elements or features. Thus, the term “below” can encompass both above and below orientations. Furthermore, the device may be oriented in other ways (e.g., rotated 90 degrees or oriented in other orientations), and thereby the spatial relative descriptive terms used herein shall be interpreted accordingly.

[0050] The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," "having," "containing," "involving," "characterized by," "characterized into" and variations thereof herein, is meant to encompass the items listed thereafter, and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "connected," "coupled," and "in communication with" used herein are intended to include any form of interaction between components. Any single component of the present disclosure can be replaced by multiple components and any stated integer number of components can be implemented by multiple components. The terms "a," "an" and "the" used herein mean "one or more." The term "plurality" used herein means "two or more." The term "another" used herein means "at least a second or one or more." The term "about" used herein means "approximately," "around," or "circa." The term "substantially" used herein means "essentially," "very nearly," or "for all practical purposes." The term "exemplary" used herein means "an example of." The term "coupled" used herein means directly or indirectly connected, linked, or associated.

[0051] As is conventional in the art, some embodiments are described and shown in terms of functional blocks, units, and / or modules. Those skilled in the art will understand that these blocks, units, and / or modules are physically implemented by electronic (or optical) circuits such as logic circuits, discrete components, microprocessors, hardwired circuits, memory elements, wiring connections, and the like which can be formed using semiconductor-based fabrication techniques or other manufacturing techniques. In cases where the blocks, units and / or modules are implemented by microprocessors or other similar hardware, they can be programmed and controlled by software (e.g., microcode) to perform the various functions discussed herein and, optionally, can be driven by firmware and / or software. It is also contemplated that each block, unit and / or module can be implemented by dedicated hardware as well as in combination with a processor (e.g., one or more programmed microprocessors and associated circuitry) that performs some functions. Moreover, each block, unit and / or module of some embodiments can be physically separated into two or more interacting and discrete blocks, units and / or modules without departing from the scope of the inventive concepts. Furthermore, blocks, units and / or modules of some embodiments can be physically combined into more complex blocks, units and / or modules without departing from the scope of the inventive concepts.

[0052] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms such as "comprises," "comprising," "includes," "including," "contains," "containing," "consists," "consisting," "consists of," and the like are used herein to indicate the presence of the stated features, integers, steps, operations, elements, components, and / or groups thereof, but not to the exclusion of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It is further noted that the use of the terms "a" and "one" and "the" and similar referents in the context of describing the application (especially in the context of claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or specifically contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein and each separate value is incorporated into the specification as if it were individually recited herein. The indefinite articles "a" and "an," as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean one or more. The use of the term "or" in the context of describing aspects of the application is to be interpreted in the inclusive sense, i.e., "and / or," unless otherwise stated.

[0053] Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same components, and repetitive description of the same components is omitted.

[0054] Figure 1 is a block diagram of an embodiment of a display apparatus constructed according to the principles of the present invention.

[0055] Referring to Figure 1 , the display apparatus 1000 can include a pixel unit 100, a scan driver 200, an emission driver 300, a data driver 400, and a controller 500.

[0056] The pixel unit 100 displays an image. The pixel unit 100 includes pixels PX disposed in connection with data lines D1 to Dm, scan lines S1 to Sn, and emission control lines E1 to En. The pixels PX can receive voltages of a first driving power source VDD, a second driving power source VSS, and an initialization power source from the outside.

[0057] In addition, the pixels PX can be connected to one or more scan lines Si and emission control lines Ei corresponding to a pixel circuit structure. The pixels PX can include a driving transistor, a plurality of switching transistors implemented by at least one of an n-type transistor and a p-type transistor, and a light emitting element.

[0058] The controller 500 can receive an input control signal and input image data IDATA from an image source such as an external graphic device. The controller 500 can include a timing controller that generates image data RGB suitable for an operating condition of the pixel unit 100 based on the input image data IDATA and provides the image data RGB to the data driver 400.

[0059] In an embodiment, the timing controller can generate a first control signal SCS for controlling a driving timing of the scan driver 200, a second control signal ECS for controlling a driving timing of the emission driver 300, and a third control signal DCS for controlling a driving timing of the data driver 400 based on the input control signal, and can provide the first control signal SCS, the second control signal ECS, and the third control signal DCS to the scan driver 200, the emission driver 300, and the data driver 400, respectively.

[0060] In an embodiment, the controller 500 can control a supply timing of the start signal EFLM included in the second control signal ECS based on a dimming signal used to determine a display luminance of the pixel unit 100. Here, dimming refers to a technique for limiting a maximum luminance of the pixel unit 100 (e.g., a luminance of a maximum gray scale of the pixel unit 100). For example, dimming can refer to displaying an image by selecting one of a plurality of preset dimming levels, and the luminance of the maximum gray scale can change to 350 nits, 250 nits, 200 nits, etc. corresponding to the dimming level. For example, as the dimming level increases, the maximum luminance of the pixel unit 100 increases.

[0061] In an embodiment, the controller 500 can determine whether an image is a moving image or a still image based on the input image data IDATA, and determine a driving operation of the display device 1000 as a driving operation of a moving image mode or a driving operation of a still image mode.

[0062] In addition, the controller 500 can control the supply timing of the start signal EFLM based on an ambient temperature of the display device 1000.

[0063] The scan driver 200 can receive the first control signal SCS from the controller 500. The scan driver 200 can supply a scan signal to the scan lines S1 to Sn in response to the first control signal SCS. The first control signal SCS can include a scan start signal for the scan signal and a plurality of clock signals.

[0064] The scan signal can be set to a gate-on level (e.g., a low voltage) corresponding to a type of a transistor to which the corresponding scan signal is supplied. A transistor receiving the scan signal when the scan signal is supplied can be set to an on state. For example, a gate-on level (e.g., a gate-on voltage) of the scan signal supplied to a P-channel metal oxide semiconductor (PMOS) transistor can be a logic low level, and a gate-on level (e.g., a gate-on voltage) of the scan signal supplied to an N-channel metal oxide semiconductor (NMOS) transistor can be a logic high level. Hereinafter, the meaning of the expression "supplying a scan signal" can be understood as the expression "supplying a scan signal at a logic level for turning on a transistor controlled by the scan signal."

[0065] The emission driver 300 can receive the second control signal ECS from the controller 500. The emission driver 300 can supply an emission control signal to the emission control lines E1 to En in response to the second control signal ECS. The second control signal ECS can include a start signal EFLM for the emission control signal and a plurality of clock signals.

[0066] The emission control signal can be set to a gate-off level (e.g., a high voltage). Upon supply of the emission control signal, the transistor receiving the emission control signal can be turned off, and in other cases can be set to an on state. Hereinafter, the expression "supply of the emission control signal" can be understood as the expression "supply of the emission control signal in a logic level for turning off the transistor controlled by the emission control signal".

[0067] Hereinafter, the period in which the emission control signal is supplied (e.g., the period in which the emission control signal of the gate-off level is supplied) can be understood as a non-emission period of the corresponding pixel, and the period in which the emission control signal is not supplied (e.g., the period in which the emission control signal of the gate-on level is supplied) can be understood as an emission period of the corresponding pixel.

[0068] The data driver 400 can receive a third control signal DCS from the controller 500. The data driver 400 can convert the image data RGB into an analog data signal (e.g., a data voltage) in response to the third control signal DCS, and supply the data signal to the data lines D1 to Dm.

[0069] Referring to Figure 1 , for convenience of description, each of the scan driver 200 and the emission driver 300 is a single configuration, but embodiments are not limited thereto. For example, the scan driver 200 can include a plurality of scan drivers that supply at least one of the different waveforms of the scan signal, respectively. In addition, at least a part of the scan driver 200 and the emission driver 300 can be integrated into one driving circuit, module, or the like.

[0070] In embodiments, the display apparatus 1000 can further include a power supply. The power supply can supply a voltage of a first driving power source VDD and a voltage of a second driving power source VSS for driving the pixel PX to the pixel unit 100.

[0071] Figure 2 is Figure 1 a circuit diagram of an example of a pixel of the display apparatus.

[0072] In Figure 2 , for convenience of description, a pixel 10 disposed on an i-th horizontal line (e.g., an i-th pixel row) and connected to a j-th data line Dj (i.e., Figure 1 , an example of a pixel PX in

[0073] Referring to Figure 2 , the pixel 10 can include a light emitting element LD, first to seventh transistors M1 to M7, and a storage capacitor Cst. In addition, a capacitor Cld connected in parallel to the light emitting element LD can also be included.

[0074] The first electrode of the light emitting element LD can be connected to one electrode (e.g., the fourth node) of the sixth transistor M6, and the second electrode can be connected to the second driving power source VSS. The light emitting element LD can generate light of a predetermined brightness corresponding to the amount of current (e.g., a driving current) supplied from the first transistor M1.

[0075] In an embodiment, the light emitting element LD can be an organic light emitting diode including an organic light emitting layer. In another embodiment, the light emitting element LD can be an inorganic light emitting element formed of an inorganic material. In another embodiment, the light emitting element LD can be a light emitting element configured by a combination of an inorganic material and an organic material. Alternatively, the light emitting element LD can have a form in which a plurality of inorganic light emitting elements are connected in parallel and / or in series between the second driving power source VSS and the fourth node N4.

[0076] The capacitor Cld can be connected between the fourth node N4 and the second driving power source VSS. The capacitor Cld can be a parasitic capacitor, and can store a voltage difference between both ends of the light emitting element LD when the light emitting element LD emits light.

[0077] The first transistor M1 can be connected between the second node N2 and the third node N3. The first transistor M1 can generate a driving current and supply the driving current to the light emitting element LD. The gate electrode of the first transistor M1 can be connected to the first node N1. The first transistor M1 can control the amount of current (e.g., a driving current) flowing from the first driving power source VDD to the second driving power source VSS via the light emitting element LD based on the voltage of the first node N1. To this end, the first driving power source VDD can be set to a voltage higher than the voltage of the second driving power source VSS.

[0078] The second transistor M2 can be connected between the jth data line Dj (hereinafter referred to as a data line) and the second node N2. The gate electrode of the second transistor M2 can be connected to the ith first scan line S1_i (hereinafter referred to as a first scan line). When a first scan signal is supplied to the first scan line S1_i, the second transistor M2 can be turned on to electrically connect the data line Dj and the second node N2.

[0079] The third transistor M3 can be connected between the first node N1 and the third node N3. The gate electrode of the third transistor M3 can be connected to the first scan line S1_i. The second transistor M2 and the third transistor M3 can be turned on at the same time.

[0080] The fourth transistor M4 can be connected between the first node N1 and the initialization power supply Vint. A gate electrode of the fourth transistor M4 can be connected to an i-th second scan line S2_i (hereinafter, referred to as a second scan line). The fourth transistor M4 can be turned on by a second scan signal supplied to the second scan line S2_i. When the fourth transistor M4 is turned on, a voltage of the initialization power supply Vint can be supplied to the first node N1 (e.g., a gate electrode of the first transistor M1).

[0081] The fifth transistor M5 can be connected between the first driving power supply VDD and a second node N2. A gate electrode of the fifth transistor M5 can be connected to an i-th emission control line Ei (hereinafter, referred to as an emission control line). The sixth transistor M6 can be connected between a third node N3 and the light emitting element LD. A gate electrode of the sixth transistor M6 can be connected to the emission control line Ei. The fifth transistor M5 and the sixth transistor M6 can be turned off when an emission control signal is supplied to the emission control line Ei, and can be turned on in other cases.

[0082] According to an embodiment, when the fifth transistor M5 and the sixth transistor M6 are turned on, a current flowing through the first transistor M1 can be transmitted to the light emitting element LD, and the light emitting element LD can emit light. An emission period of the light emitting element LD can be determined in correspondence with a turn-on period of the fifth transistor M5 and the sixth transistor M6. In addition, the turn-on period of the fifth transistor M5 and the sixth transistor M6 can correspond to an on duty (e.g., an emission period) of the emission control signal, and the turn-off period of the fifth transistor M5 and the sixth transistor M6 can correspond to an off duty (e.g., a non-emission period) of the emission control signal.

[0083] The seventh transistor M7 can be connected to a first electrode (e.g., a fourth node N4) of the light emitting element LD. A gate electrode of the seventh transistor M7 can be connected to an i-th third scan line S3_i (hereinafter, referred to as a third scan line). The seventh transistor M7 can be turned on by a third scan signal supplied to the third scan line S3_i to supply a voltage of the initialization power supply Vint to the first electrode of the light emitting element LD.

[0084] The storage capacitor Cst can be connected between the first driving power supply VDD and the first node N1.

[0085] In an embodiment, the first scan signal and the second scan signal can be supplied with different timings. For example, the first scan signal can be supplied after the second scan signal is supplied. The third scan signal can be supplied after the first scan signal is supplied. The relationship between the first scan signal, the second scan signal, and the third scan signal can be expressed as shown in FIG. 1B. Figure 3A

[0086] ​However, this is exemplary, and the third scan signal can be supplied at the same time as the second scan signal. In this case, the third scan line S3_i and the second scan line S2_i can be connected to each other.

[0087] Alternatively, the third scan signal can be supplied at the same time as the first scan signal. In this case, the third scan line S3_i can be connected to the first scan line S1_i.

[0088] Figure 3A and Figure 3B is a timing chart showing an example of a signal supplied to a pixel of Figure 2 .

[0089] Referring to Figure 2 , Figure 3A and Figure 3B , the emission control signal corresponding to one frame FR can define at least one emission period EP and at least one non-emission period NEP.

[0090] In an embodiment, as shown in Figure 3A , the emission control signal supplied to the emission control line Ei can define one non-emission period NEP corresponding to a gate-off level (e.g., a high level) and one emission period EP corresponding to a gate-on level (e.g., a low level). The non-emission period NEP can correspond to a blank time of the emission control signal.

[0091] The non-emission period NEP can correspond to a preset horizontal period. For example, the blank time of the emission control signal can be set to about 4 horizontal periods. Here, one horizontal period can be a period in which the scan signal is shifted or a period in which the data signal is applied in the pixel column direction.

[0092] The second scan signal, the first scan signal, and the third scan signal can be sequentially supplied to the second scan line S2_i, the first scan line S1_i, and the third scan line S3_i, respectively, in the non-emission period NEP.

[0093] When the fourth transistor M4 is turned on in response to the second scan signal, a voltage of the initialization power Vint can be supplied to the first node N1.

[0094] When the second transistor M2 and the third transistor M3 are turned on in response to the first scan signal, the data signal can be supplied to the second node N2, the first transistor M1 can be connected in a diode form, and the data signal whose threshold voltage is compensated for the first transistor M1 can be supplied to the first node N1.

[0095] When the seventh transistor M7 turns on in response to the third scan signal, the voltage of the initialization power source Vint can be supplied to the fourth node N4. At this time, the voltage of one terminal (e.g., the fourth node N4) of the capacitor Cld can be initialized to the voltage of the initialization power source Vint. Thus, when black luminance is realized or displayed, the light emitting element LD can be prevented from emitting light due to a leakage current supplied from the first transistor M1.

[0096] For example, a drive current and / or a leakage current flowing from the first transistor M1 to the light emitting element LD can pre-charge the capacitor Cld, and during a period in which the capacitor Cld is charged, the light emitting element LD can be set to a non-emission state.

[0097] Thereafter, when the supply of the emission control signal is stopped, the emission period EP can start. For example, the fifth transistor M5 and the sixth transistor M6 can turn on by a low level of the emission control signal supplied to the emission control line Ei, and the light emitting element LD can emit light based on a drive current flowing from the first transistor M1.

[0098] When the frame driving operation for still image display as shown in FIG. 6 is repeated, the non-emission period NEP can be repeated for a relatively long period, and thus image flicker (e.g., an image flicker phenomenon) can be visually recognized. To prevent or minimize the visual recognition of the image flicker, as shown in FIG. 7, the emission control signal can be supplied such that one frame FR includes a plurality of emission cycles CYC1, CYC2, CYC3, and CYC4. Figure 3A Figure 3B For example, in the case of high luminance emission in which the image flicker cannot be well recognized, the driving operation as shown in FIG. 6 (e.g., referred to as a 1-cycle driving operation) can be applied. However, in a display luminance range of about 200 nits or less, in order to prevent or minimize the visual recognition of the image flicker, one frame FR can include a plurality of emission cycles.

[0099] For example, in the case of high luminance emission in which the image flicker cannot be well recognized, the driving operation as shown in FIG. 6 (e.g., referred to as a 1-cycle driving operation) can be applied. However, in a display luminance range of about 200 nits or less, in order to prevent or minimize the visual recognition of the image flicker, one frame FR can include a plurality of emission cycles. Figure 3A In an embodiment, as shown in FIG. 8, in one frame FR, the emission control signal can define a plurality of non-emission periods NEP1, NEP2, NEP3, and NEP4 corresponding to a high level and a plurality of emission periods EP1, EP2, EP3, and EP4 corresponding to a low level.

[0100] Figure 3B The waveform of the emission control signal supplied to the emission control line Ei can be similar to the waveform of the start signal EFLM supplied from the controller 500.

[0101] The waveform of the emission control signal supplied to the emission control line Ei can be similar to the waveform of the start signal EFLM supplied from the controller 500.

[0102] ​​In an embodiment, the initialization operation of the gate voltage of the first transistor M1, the data write operation, and the initialization operation of the voltage of the fourth node N4 can be performed in the first non-emission period NEP1, and the corresponding operations can not be performed in the second non-emission period NEP2, the third non-emission period NEP3, and the fourth non-emission period NEP4.

[0103] In one frame FR, the lengths of the emission periods CYC1, CYC2, CYC3, and CYC4 can be substantially the same. In other words, the lengths of the first non-emission period NEP1 to the fourth non-emission period NEP4 can be substantially the same, and the lengths of the first emission period EP1 to the fourth emission period EP4 can be substantially the same.

[0104] As described above, the first non-emission period NEP1 to the fourth non-emission period NEP4 are repeated in one frame FR. Accordingly, a difference in brightness between a plurality of frames FR can be reduced, thereby reducing or minimizing visual recognition of image flicker (e.g., image flicker phenomenon).

[0105] In Figure 3B , the emission control signal has four emission periods CYC1, CYC2, CYC3, and CYC4, but embodiments are not limited to the waveform of the emission control signal. For example, the emission control signal can include two emission periods or eight emission periods according to design and / or conditions.

[0106] However, the length of the first emission period EP1 after the first non-emission period NEP1 in which the voltage of the fourth node N4 is initialized and the data signal is written is relatively short compared to the length of the emission period EP of Figure 3A . Accordingly, problems such as bleeding and trailing can occur. This will be described in detail with reference to Figure 4 .

[0107] Figure 4 is a timing chart showing a change in current of a light emitting element of a pixel of a display apparatus flowing to Figure 1 .

[0108] Referring to Figure 2 , Figure 3A , Figure 3B , and Figure 4 , the pixel 10 can include a red pixel for emitting red light, a green pixel for emitting green light, and a blue pixel for emitting blue light according to the light emitting element LD.

[0109] Figure 4A first current IR flowing through the light emitting element LD of the red pixel (hereinafter, referred to as a red light emitting element), a second current IG flowing through the light emitting element LD of the green pixel (hereinafter, referred to as a green light emitting element), and a third current IB flowing through the light emitting element LD of the blue pixel (hereinafter, referred to as a blue light emitting element) are shown.

[0110] As described above, after the voltage of the fourth node N4 is initialized in the non-emission period NEP, the capacitor Cld can be charged until the light emitting element LD emits light when the fifth transistor M5 and the sixth transistor M6 are turned on.

[0111] Due to the efficiency difference according to the inherent characteristics of the red light emitting element, the green light emitting element, and the blue light emitting element, a difference in charging time of each of the initialized capacitors Cld can occur. Accordingly, as shown in Figure 4 the time or duration until the first current IR, the second current IG, and the third current IB reach predetermined values for emission can be different from each other.

[0112] When the frame FR includes a plurality of emission periods CYC1, CYC2, CYC3, and CYC4, Figure 3B the length of the first emission period EP1 is shorter than the length of the emission period EP of Figure 3A When the length of the first emission period EP1 is shortened, the time for completely charging the capacitor Cld can be insufficient. For example, the green light emitting element having a relatively slow response speed can not emit or emit light having a luminance corresponding to the data signal in the first emission period EP1.

[0113] In particular, when the gray scale and / or luminance between frames significantly vary, due to the insufficient time for charging the capacitor Cld, the corresponding pixel can not emit light with the luminance of the provided data signal, and image defects such as color trailing and bleeding can be visually recognized.

[0114] As described above, there is a trade-off relationship between image flicker and color trailing (or bleeding). For example, as the emission period repeats in one frame FR, it is more advantageous in terms of image flicker, but as the emission period decreases, it is advantageous in terms of color trailing (or bleeding).

[0115] The display apparatus according to the embodiment can control the emission control signal according to a predetermined condition in order to improve image quality during a pulse dimming driving operation including a plurality of emission periods.

[0116] Figure 5 is a timing chart showing an example of a method of driving a display apparatus Figure 1 and Figure 6 is a timing chart showing an example of a method of driving a display apparatus Figure 1a timing diagram of another example of a method of a display apparatus.

[0117] Referring to Figure 1 , Figure 2 , Figure 5 and Figure 6 , the controller 500 can control the first emission period EP1 to be longer than the other emission periods EP2, EP3, and EP4.

[0118] The controller 500 can output a start signal EFLM, and the emission driver 300 can shift and output the emission control signal in units of horizontal lines based on the start signal EFLM.

[0119] The lengths of the non-emission periods NEP1, NEP2, NEP3, and NEP4 of the emission control signal supplied to the emission control line Ei having the gate-off level can be substantially the same.

[0120] In an embodiment, as shown in Figure 5 , the lengths of the second emission period EP2, the third emission period EP3, and the fourth emission period EP4, which are the other emission periods except for the first emission period EP1, can be substantially the same. Accordingly, the lengths of the second emission cycle CYC2, the third emission cycle CYC3, and the fourth emission cycle CYC4 can all be substantially the same. In comparison with Figure 3B and Figure 5 , the length of the first emission period EP1 can increase, and the lengths of the second emission period EP2, the third emission period EP3, and the fourth emission period EP4 can decrease.

[0121] For example, the first emission period EP1 can occupy about 70% of the total emission time of one frame FR, and each of the second emission period EP2, the third emission period EP3, and the fourth emission period EP4 can occupy about 10% of the total emission time of one frame FR.

[0122] In an embodiment, as shown in Figure 6 , the lengths of the second emission period EP2, the third emission period EP3, and the fourth emission period EP4 can be different from each other. For example, the length of the second emission period EP2 can be longer than the length of the third emission period EP3, and the length of the third emission period EP3 can be longer than the length of the fourth emission period EP4. The ratio of the second emission period EP2, the third emission period EP3, and the fourth emission period EP4 can be determined according to the driving characteristics, size, etc. of the display apparatus 1000.

[0123] After the first non-emission period NEP1 of initializing the voltage of the fourth node N4, time for the first emission period EP1 for charging the capacitor Cld is sufficiently secured or obtained, and thus all of the red light emitting element, the green light emitting element, and the blue light emitting element can emit corresponding light. Although the second emission period EP2, the third emission period EP3, and the fourth emission period EP4 are shorter than those in the case of FIG. 1, the pixel 10 can emit light having a desired brightness by charging the voltage in the capacitor Cld in the first emission period EP1. Figure 3B

[0124] Thus, color dragging and color bleeding in the driving method including the plurality of emission periods CYC1 to CYC4 can be minimized or prevented, and image quality can be improved.

[0125] For example, Figure 5 and Figure 6 The number of emission periods CYC1 to CYC4 is an example, and the number of emission periods can vary according to a driving condition of the display device 1000. For example, one frame FR can include eight emission periods or two emission periods.

[0126] Figure 7 is a block diagram illustrating an example of a controller and an emission driver of the display device of Figure 1

[0127] Referring to Figure 2 , Figure 5 and Figure 7 , the controller 500 can generate a start signal EFLM based on a change in input image data IDATA, determine a dimming level DIM of a display brightness, and an ambient temperature TEMP. The emission driver 300 can output an emission control signal EM based on the start signal EFLM.

[0128] The controller 500 can determine whether a target frame is a moving image frame or a still image frame by analyzing a change in input image data IDATA between frames. For example, the controller 500 can compare a gray level or a sum of gray levels of input image data IDATA of consecutive frames or subsequent frames. When the gray level or the sum of gray levels changes, the controller 500 can determine that a corresponding frame is a moving image frame and can drive in a moving image mode. On the other hand, when the gray level or the sum of gray levels of consecutive preset frames is the same, the controller 500 can determine that a corresponding frame is a still image frame and can drive in a still image mode.

[0129] Alternatively, when a still image is displayed, input image data IDATA can not be supplied to the controller 500 from an external graphic source after a first frame of the still image. For example, when input image data IDATA is not supplied to the controller 500, the controller 500 can drive in a still image mode. ​​

[0130] However, this is exemplary, and the method of determining whether the corresponding frame is a moving image frame or a still image frame and / or the method of selecting one of the moving image mode and the still image mode can be determined by various known methods of analyzing the input image data IDATA.

[0131] In an embodiment, the controller 500 can determine the length of the gate-on period (e.g., emission period) of the emission control signal EM according to the moving image frame of the moving image mode or the still image frame of the still image mode. Here, the moving image can include an image change caused by scrolling of the screen or the like.

[0132] In the still image in which the image does not change, the image flicker can be more easily visually recognized than in the moving image. In contrast, in the moving image in which the gray scale changes, the smear and the bleeding can be more easily visually recognized than in the still image. Accordingly, the length of the first emission period EP1 of the moving image frame can be set to be longer than the length of the first emission period EP1 of the still image frame. In this case, the length of the second emission period EP2 of the moving image frame can be shorter than the length of the second emission period EP2 of the still image frame.

[0133] For example, in the case of the still image mode, since the smear or the bleeding is not a problem, the controller 500 can output the start signal EFLM having a waveform similar to that of Figure 3B In the case of the moving image mode, the controller 500 can output the start signal EFLM to prevent the smear or the bleeding. Figure 5 In the case of the moving image mode, the controller 500 can output the start signal EFLM to prevent the smear or the bleeding.

[0134] In an embodiment, in the moving image mode, the controller 500 can further control the lengths of the emission periods EP1, EP2, EP3, and EP4 of the moving image frame based on the dimming level DIM for determining the display luminance. The controller 500 can include a lookup table in which a weight or the like for determining the lengths of the emission periods EP1, EP2, EP3, and EP4 corresponding to the dimming level DIM is set. Alternatively, the controller 500 can further include a lookup table, a hardware configuration, and / or an algorithm in which an equation or the like for calculating the weight according to the dimming level DIM (e.g., the display luminance) is set.

[0135] As the display luminance increases, the driving current supplied to the light emitting element LD can increase. According to the relationship between the amount of charge charged in the capacitor Cld and the current, the charging time for charging the capacitor Cld can decrease as the driving current increases.

[0136] Accordingly, to secure or obtain a time for completely charging the capacitor Cld, the length (e.g., width) of the first emission period EP1 can also increase as the display brightness decreases. As the length of the first emission period EP1 increases, the lengths of the remaining emission periods EP2, EP3, and EP4 can decrease.

[0137] In an embodiment, in the moving image mode, the controller 500 can also control the lengths of the emission periods EP1, EP2, EP3, and EP4 of the moving image frame based on the ambient temperature TEMP of the display apparatus. The controller 500 can also include a temperature sensor that senses the ambient temperature TEMP.

[0138] The controller 500 can include a lookup table in which weights or the like for determining the lengths of the emission periods EP1, EP2, EP3, and EP4 corresponding to the ambient temperature TEMP are set. Alternatively, the controller 500 can also include a lookup table, a hardware configuration, and / or an algorithm in which an equation for calculating the weights according to the ambient temperature TEMP is set.

[0139] Due to the element characteristics of the light emitting element LD, the resistance of the light emitting element LD can increase as the ambient temperature TEMP decreases. For example, as the ambient temperature TEMP decreases, the driving current corresponding to the same brightness and / or the same gray scale can decrease.

[0140] Accordingly, under the condition of the same brightness and / or the same gray scale, as the ambient temperature TEMP decreases, the first emission period EP1 can be longer. As the first emission period EP1 increases, the lengths of the remaining emission periods EP2, EP3, and EP4 can decrease.

[0141] Figure 8A 、 Figure 8B and Figure 8C is a timing chart illustrating an example of the emission control signal output according to the display brightness.

[0142] Referring to Figure 7 、 Figure 8A 、 Figure 8B and Figure 8C , the width of the emission period corresponding to the gate-on period of the emission control signal EM in the moving image frame MFR can be controlled based on the display brightness DBV1, DBV2, and DBV3 determined corresponding to the dimming level.

[0143] The first display brightness DBV1 can be lower than the second display brightness DBV2, and the second display brightness DBV2 can be lower than the third display brightness DBV3. For example, the first display brightness DBV1 can be about 2 nits, the second display brightness DBV2 can be about 10 nits, and the third display brightness DBV3 can be about 30 nits. As described above, as the display brightness decreases, the length of the first emission period EP1 can increase to become longer.

[0144] Accordingly, the first length L1 of the first emission period EP1 corresponding to the first display brightness DBV1 can be longer than the second length L2 of the first emission period EP1 corresponding to the second display brightness DBV2. Further, the second length L2 of the first emission period EP1 can be set to be longer than the third length L3 of the first emission period EP1 corresponding to the third display brightness DBV3.

[0145] As the length (e.g., width) of the first emission period EP1 increases, the length (e.g., width) of the subsequent emission period can relatively decrease.

[0146] For example, the gate-off period of the emission control signal EM can be set to the same length regardless of the display brightnesses DBV1, DBV2, and DBV3.

[0147] As described above, the display apparatus can control the length (e.g., width of the first gate-on period of the emission control signal EM) of the first emission period EP1 of the moving image frame MFR according to the change in the display brightness in the moving image mode. Accordingly, the charging time of the capacitor Cld can be sufficiently secured or obtained. Accordingly, the color trailing and bleeding of the display apparatus to which the pulse dimming including a plurality of emission periods is applied can be minimized or prevented, and the image quality can be improved.

[0148] Figure 9A 、 Figure 9B and Figure 9C is a timing chart showing an example of the emission control signal output according to the ambient temperature.

[0149] Referring to Figure 7 、 Figure 9A 、 Figure 9B and Figure 9C , the length of the emission period corresponding to the gate-on period of the emission control signal EM in the moving image frame MFR can be controlled based on the ambient temperature TEMP.

[0150] The first temperature TEM1 can be lower than the second temperature TEM2, and the second temperature TEM2 can be lower than the third temperature TEM3. For example, the first temperature TEM1 can be about 10℃, the second temperature TEM2 can be about 20℃, and the third temperature TEM3 can be about 30℃. As described above, as the ambient temperature TEMP decreases, the first emission period EP1 can increase to become longer.

[0151] Accordingly, the fourth length L4 of the first emission period EP1 corresponding to the first temperature TEM1 can be set to be longer than the fifth length L5 of the first emission period EP1 corresponding to the second temperature TEM2, under the condition of the same display brightness. Also, the fifth length L5 of the first emission period EP1 can be set to be longer than the sixth length L6 of the first emission period EP1 corresponding to the third temperature TEM3, under the condition of the same display brightness.

[0152] As the length of the first emission period EP1 increases, the length of the subsequent emission period can relatively decrease. For example, the gate-off period of the emission control signal EM can be set to be the same regardless of the ambient temperature TEMP.

[0153] As described above, the display apparatus controls the width of the first emission period EP1 of the moving image frame MFR (e.g., the width of the first gate-on period of the emission control signal EM) according to the change in the ambient temperature TEMP in the moving image mode. Accordingly, the charging time of the capacitor Cld can be sufficiently secured or obtained. Accordingly, the color trailing and bleeding of the display apparatus to which the pulse dimming including a plurality of emission periods is applied can be minimized or prevented, and the image quality can be improved.

[0154] Figure 10 is a timing chart illustrating an example of the emission control signal output in the still image mode, and Figure 11 is a timing chart illustrating another example of the emission control signal output in the still image mode.

[0155] Referring to Figure 1 , Figure 2 , Figure 7 , Figure 10 and Figure 11 , the controller 500 can control the emission period of the emission control signal EM based on the change in the input image data IDATA and the display brightness.

[0156] The emission period can correspond to the number of discontinuous outputs of the gate-on period of the emission control signal EM during one frame. In other words, one emission period can include one non-emission period (e.g., the gate-off period of the emission control signal) and one emission period (e.g., the gate-on period of the emission control signal) in succession in one frame.

[0157] Figure 10 and Figure 11 illustrate an embodiment in which the target number of the emission period is set to four periods. In the embodiment, the controller 500 can gradually increase the number of the emission period to become the target number of the emission period as the frames elapse. For example, as Figure 10As shown in FIG. 10, the number of emission periods of the second frame FR2 can be greater than the number of emission periods of the first frame FR1.

[0158] As described above, when a still image is displayed, image flicker has a greater impact on image quality than smearing. Thus, the target number of emission periods in the case of displaying a still image can be two or more periods.

[0159] However, the first frame (e.g., the first frame FR1) of a still image is a frame in which the grayscale changes from another image. Since the first frame FR1 requires sufficient time to charge the capacitor Cld of the light emitting element LD, a long emission period EP is required.

[0160] Thus, as Figure 10 As shown in FIG. 10, the first frame FR1 of the still image mode MODE1 in which a still image is displayed can be controlled to include one emission period. Thereafter, the number of emission periods can gradually increase to the target number of emission periods as the frames elapse.

[0161] For example, the output of the emission control signal EM can be controlled so that the number of emission periods of the second frame FR2 is greater than the number of emission periods of the first frame FR1.

[0162] Accordingly, smearing or bleeding can be minimized or prevented by sufficiently securing or obtaining the charging time of the capacitor Cld in the first frame FR1 in which the image changes. In addition, the emission period increases after the second frame FR2 of the still image, and thus image flicker can be prevented or minimized, and image quality can be improved.

[0163] In an embodiment, since the image changes for each frame in the moving image mode, the driving method described with reference to Figure 5 may be applied instead of the driving method of Figure 10 .

[0164] Since the driving operation of selecting one of the still image mode MODE1 and the moving image mode is described above with reference to Figure 7 , repetitive description thereof is omitted for the sake of convenience of description.

[0165] In an embodiment, in the still image mode MODE1, the controller 500 can determine the number of emission periods for each frame based on the display brightness.

[0166] Since the speed for charging the capacitor Cld increases as the display brightness increases, smearing or bleeding is not visually recognized even if the emission time of the first frame FR1 is relatively short. For example, Figure 10 shows the change in the emission period at the first display brightness DBV1, and Figure 11The change in the number of emission periods at a second display brightness DBV2 higher than the first display brightness DBV1 is shown. For example, the number of emission periods of the first frame FR1 corresponding to the first display brightness DBV1 (see Figure 10 ) can be less than the number of emission periods of the first frame FR1 corresponding to the second display brightness DBV2 (see Figure 11 ).

[0167] Thereafter, the number of emission periods in the third frame FR3 and the fourth frame FR4 at which the number of emission periods reaches or becomes the target number can be the same regardless of the display brightness.

[0168] The color trailing or bleeding can be minimized or prevented by sufficiently securing or obtaining the charging time of the capacitor Cld in the first frame FR1 in which the image changes. In addition, after the second frame FR2 of the still image, the emission period is increased, thereby preventing or minimizing the image flicker, so that the image quality can be improved.

[0169] Further, since the number of emission periods included in the initial frame of the still image is differently set according to the display brightness, the problems of the image flicker and the color trailing of the image of the display apparatus to which the pulse dimming is applied can be simultaneously solved, so that the image quality can be improved.

[0170] Figure 12A and Figure 12B are timing charts showing examples of the emission control signal output according to the display brightness in the moving image mode.

[0171] Referring to Figure 7 , Figure 10 , Figure 12A and Figure 12B , in the moving image mode MODE2, the number of emission periods of the first frame FR1 to the p-th (where p is an integer greater than 1) frame can be the same.

[0172] The controller 500 can select one of the still image mode MODE1 and the moving image mode MODE2 by analyzing the change of the input image data IDATA.

[0173] In the moving image mode MODE2, the color trailing or bleeding can have a greater influence on the image quality than the image flicker. Therefore, it is required to sufficiently secure or obtain the length of the emission period immediately after the period in which the data signal is written. Accordingly, the target number of the emission period of the still image mode MODE1 can be greater than the target number of the emission period of the moving image mode MODE2 under the condition of the same display brightness. For example, as Figure 12AAs shown in FIG. 2, the target period of the moving image mode MODE2 corresponding to the first display brightness DBV1 can be one period. Thus, the emission control signal EM can be supplied once in each of the first frame FR1 to the fourth frame FR4.

[0174] For example, since the capacitor Cld is relatively quickly charged when the display brightness increases, the frame can include a plurality of emission periods. For example, as shown in FIG. 3, the first frame FR1 to the fourth frame FR4 can each include two emission periods. Figure 12B As shown in FIG. 4, in the second display brightness DBV2 of the moving image mode MODE2, each of the first frame FR1 to the fourth frame FR4 can include two emission periods. For example, the emission control signal EM can be supplied twice in each of the first frame FR1 to the fourth frame FR4.

[0175] As described above, the display apparatus determines whether an image is a moving image or a still image, and determines a display brightness to determine the number of emission periods for each frame. Thus, the image quality corresponding to the change of the image and the change of the display brightness can be further improved.

[0176] Figure 13A and Figure 13B is a timing chart showing an example of the emission control signal output in the still image mode according to the ambient temperature.

[0177] Referring to Figure 7 , Figure 13A and Figure 13B , the controller 500 can control the change of the emission period based on the ambient temperature TEMP in the still image mode MODE1.

[0178] As described above, as the ambient temperature TEMP decreases, the driving current corresponding to the same brightness and / or the same gray scale can decrease. Thus, it is necessary to secure or obtain a sufficient emission period at a relatively low ambient temperature TEMP.

[0179] Figure 13A shows the output of the emission control signal EM at a first temperature TEM1, and Figure 13B shows the output of the emission control signal EM at a second temperature TEM2. The first temperature TEM1 can be lower than the second temperature TEM2.

[0180] In an embodiment, the number of frames required to increase the number of emission periods to the target number of emission periods corresponding to the first temperature TEM1 at the same display brightness can be greater than the number of frames required to increase the number of emission periods to the target number of emission periods corresponding to the second temperature TEM2. For example, as shown in FIG. 6, Figure 13A and Figure 13BAs illustrated in FIG. 10, at the first temperature TEM1, the emission control signal EM can be supplied four times corresponding to the target number in the fourth frame FR4, and at the second temperature TEM2, the emission control signal EM can be supplied four times in the third frame FR3.

[0181] Accordingly, the display apparatus can further improve image quality by adaptively controlling the emission period of the initial frame of the still image corresponding to the temperature change.

[0182] As described above, the display apparatus according to the embodiment of the disclosure can control the length of the emission period and / or the number of emission periods of the pulse dimming driving operation based on the change of the image data, the display luminance, and the ambient temperature. Accordingly, image flicker and color bleeding or bleeding of both the moving image and the still image can be minimized or prevented, so that the image quality can be improved.

[0183] Although the disclosure has been described with reference to the embodiments of the disclosure, it will be understood by those skilled in the art that various changes and modifications can be made to the disclosure without departing from the spirit and scope of the disclosure disclosed in the appended claims.

Claims

1. A display device, comprising: Pixel; A scan driver configured to supply scan signals to the pixel via scan lines; A transmit driver configured to supply a transmit control signal, comprising a plurality of gate on-level signals, to the pixel via a transmit control line in a frame, the plurality of gate on-level signals being used to generate a plurality of transmit periods of the pixel; A data driver configured to supply data signals to the pixel via a data line; as well as A controller configured to control the waveform of the transmit control signal. Wherein, the length of the first launch period among the plurality of launch periods is longer than the length of another launch period among the plurality of launch periods, and The controller is configured to analyze changes in image data to select one of a motion image mode and a still image mode, and is configured to adjust the length of the transmission period based on a motion image frame of the motion image mode or a still image frame of the still image mode.

2. The display device as claimed in claim 1, wherein: The multiple non-emission periods of the pixel are generated by multiple gate turn-off level signals of the emission control signal, and In the frame, the lengths of the multiple non-transmission periods are the same.

3. The display device as claimed in claim 2, wherein, The lengths of the plurality of transmission periods correspond to the widths of the plurality of gate on-level signals of the transmission control signal, respectively.

4. The display device as claimed in claim 1, wherein, The remaining launch periods, excluding the first launch period, are of the same length among the multiple launch periods.

5. The display device as claimed in claim 1, wherein, In the frame, the length of the second transmission period among the plurality of transmission periods is longer than the length of the third transmission period among the plurality of transmission periods.

6. The display device as claimed in claim 1, wherein, The length of the first transmission period of the moving image frame is longer than the length of the first transmission period of the still image frame, and The length of the second transmission period of the moving image frame is shorter than the length of the second transmission period of the still image frame.

7. The display device as claimed in claim 1, wherein, In the motion picture mode, the controller is configured to control the length of the transmission period of the motion picture frame based on the display brightness.

8. The display device as claimed in claim 7, wherein, The length of the first transmission period corresponding to the first display brightness is longer than the length of the first transmission period corresponding to the second display brightness, which is greater than the first display brightness.

9. The display device as claimed in claim 1, wherein, In the motion picture mode, the controller is configured to control the length of the transmission period of the motion picture frame based on the ambient temperature of the display device.

10. The display device as claimed in claim 9, wherein, Under the same display brightness conditions, the length of the first emission period corresponding to the first temperature is longer than the length of the first emission period corresponding to the second temperature which is greater than the first temperature.

11. A display device, comprising: Pixel; A scan driver configured to supply scan signals to the pixel via scan lines; A transmit driver configured to supply a transmit control signal, comprising a plurality of gate on-level signals, to the pixel via a transmit control line, the plurality of gate on-level signals being used to generate a plurality of transmit cycles of the pixel; A data driver configured to supply data signals to the pixel via a data line; as well as A controller configured to control the number of transmission cycles within a frame based on changes in image data and display brightness. Wherein, the number of emission cycles of the first frame corresponding to the first display brightness is smaller than the number of emission cycles of the first frame corresponding to a second display brightness greater than the first display brightness, and The number of transmission cycles for the k-th frame corresponding to the first display brightness is the same as the number of transmission cycles for the k-th frame corresponding to the second display brightness, where k is an integer greater than 3, and The controller is configured to analyze changes in the image data to select one of a still image mode and a moving image mode. When the still image mode begins, the controller is configured to gradually increase the number of transmission cycles to a target number of transmission cycles as multiple frames pass. The number of transmission cycles of the kth frame in the still image mode is greater than the number of transmission cycles of the kth frame in the moving image mode.

12. The display device as claimed in claim 11, wherein, The controller is configured to gradually increase the number of transmission cycles to the target number of transmission cycles as multiple frames pass.

13. The display device as claimed in claim 12, wherein, The number of transmission cycles in the second frame of the plurality of frames is greater than the number of transmission cycles in the first frame of the plurality of frames.

14. The display device as claimed in claim 11, wherein, The controller is also configured to control the variation of the emission cycle based on the ambient temperature of the display device, and Under the same display brightness, the number of frames required to increase the number of transmission cycles to the target number of transmission cycles corresponding to the first temperature is greater than the number of frames required to increase the number of transmission cycles to the target number of transmission cycles corresponding to a second temperature greater than the first temperature.

15. A display device, comprising: Pixel; A scan driver configured to supply scan signals to the pixel via scan lines; A transmit driver configured to supply a transmit control signal, comprising a plurality of gate on-level signals, to the pixel via a transmit control line, the plurality of gate on-level signals being used to generate a plurality of transmit periods and a plurality of transmit cycles of the pixel; A data driver configured to supply data signals to the pixel via a data line; as well as The controller is configured to control the length of the transmission period and the number of transmission cycles within a frame based on changes in image data and display brightness. In the still image mode, the number of transmission cycles gradually increases over multiple frames to become the target number of transmission cycles. In the still image mode, the number of emission cycles of the first frame among the plurality of frames corresponding to the first display brightness is less than the number of emission cycles of the first frame corresponding to the second display brightness which is greater than the first display brightness, and the number of emission cycles of the kth frame corresponding to the first display brightness is the same as the number of emission cycles of the kth frame corresponding to the second display brightness, where k is an integer greater than 3.

16. The display device as claimed in claim 15, wherein, In a moving image frame of motion picture mode, the length of the first transmission period among the plurality of transmission periods is longer than the length of another transmission period among the plurality of transmission periods, and In the motion picture mode, the length of the first emission period corresponding to the first display brightness is longer than the length of the first emission period corresponding to the second display brightness which is greater than the first display brightness.

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