Display device and driving method thereof

Abstract

A display device and a driving method thereof are provided. The display device includes a display panel, a data driving circuit driving a plurality of data lines, a scan driving circuit driving a plurality of scan lines, and a driving controller controlling the data driving circuit and the scan driving circuit such that the display panel is divided into a first display area and a second display area and the first display area and the second display area are respectively operated at different frequencies during a multi-frequency mode, wherein when a still image and a moving image are simultaneously displayed in the first display area during the multi-frequency mode and a duration of the still image reaches a predetermined time, the driving controller changes an operation mode to a normal mode.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0111936, filed on September 2, 2020, which is hereby incorporated by reference for all purposes, as if fully set forth herein. Technical Field

[0003] The embodiments of the present invention described herein relate to display devices. Background Technology

[0004] In display devices, organic light-emitting diodes (OLEDs) are used to display images. These OLEDs generate light through the recombination of electrons and holes. For example, OLEDs have the advantages of fast response times and low power consumption.

[0005] Organic light-emitting display devices are provided with pixels connected to data lines and scan lines. A pixel typically includes an organic light-emitting diode (OLED) and circuitry for controlling the amount of current flowing into the OLED. The circuitry controls the amount of current flowing through the OLED from a first driving voltage to a second driving voltage in response to a data signal. At this time, light with a predetermined brightness is generated in response to the amount of current flowing through the OLED.

[0006] Recently, display devices have been used in various fields. Therefore, it is possible to display multiple different images simultaneously on a single display device. In this regard, there is a need for technologies that can reduce the power consumption of display devices displaying multiple images simultaneously while preventing degradation of display quality. Summary of the Invention

[0007] The embodiments of the present invention described herein provide a display device and a driving method thereof that can reduce power consumption and prevent display quality degradation.

[0008] Embodiments of the present invention provide a display device comprising: a display panel including a plurality of pixels respectively connected to corresponding data lines of a plurality of data lines and corresponding scan lines of a plurality of scan lines; a data driving circuit for driving the plurality of data lines; a scan driving circuit for driving the plurality of scan lines; and a drive controller for controlling the data driving circuit and the scan driving circuit such that, during a multi-frequency mode, the display panel is divided into a first display area and a second display area, and the first display area and the second display area are operated at different frequencies. In an embodiment, when a still image and a moving image are simultaneously displayed in the first display area during the multi-frequency mode and the duration of the still image reaches a predetermined time, the drive controller can change the operation mode to a normal mode.

[0009] In an embodiment, during multi-frequency mode, the first display area can be driven by a first driving frequency, and the second display area can be driven by a second driving frequency lower than the first driving frequency.

[0010] In an embodiment, during normal mode, each of the first and second display areas can be driven at a normal frequency.

[0011] In this embodiment, the first driving frequency may be the same as the normal frequency.

[0012] In an embodiment, the drive controller may include: a frequency mode determination unit that determines an operating mode based on an image signal and a control signal and outputs a mode signal; and a signal generator that outputs a data control signal and a scan control signal corresponding to the mode signal, wherein the data control signal may be provided to a data drive circuit and the scan control signal may be provided to a scan drive circuit.

[0013] In an embodiment, when a still image and a moving image are simultaneously displayed in the first display area during multi-frequency mode and the duration of the still image reaches a predetermined time, the frequency mode determination unit may change the operating mode so that the mode signal represents the normal mode.

[0014] In an embodiment, when the average brightness of a still image displayed in the first display area is higher than a reference brightness, the frequency mode determination unit may change the operating mode so that the mode signal represents a normal mode.

[0015] In an embodiment, when the average brightness of a still image displayed in the first display area is higher than a reference brightness and the duration of the still image reaches a predetermined time, the frequency mode determination unit may change the operation mode so that the mode signal represents a normal mode.

[0016] In an embodiment, when the still image displayed in the first display area is the worst pattern and the duration of the still image reaches a predetermined time, the frequency mode determination unit may change the operating mode so that the mode signal represents the normal mode.

[0017] In an embodiment, when the still image displayed in the first display area is the worst pattern and the display area of ​​the still image is larger than the reference area, the frequency mode determination unit may change the operation mode according to the duration of the still image so that the mode signal represents the normal mode.

[0018] In an embodiment, when the duration of the still image reaches a first reference time, the frequency mode determination unit can change the frequency of the second display area to a first intermediate frequency, and when the duration of the still image reaches a second reference time, the frequency mode determination unit can change the frequency of the second display area to a second intermediate frequency, wherein the second reference time may be greater than the first reference time, and the second intermediate frequency may be higher than the first intermediate frequency.

[0019] In an embodiment, when the duration of the still image reaches a third reference time, the frequency mode determination unit may change the operation mode so that the mode signal represents a normal mode, wherein the third reference time may be greater than the second reference time.

[0020] In an embodiment, when the ratio of the length of the still image in the first direction to the length of the first display area in the first direction is equal to or greater than a predetermined value, the frequency mode determination unit can determine that the display area of ​​the still image is greater than the reference area.

[0021] In an embodiment of the present invention, a method for driving a display device includes: dividing a display panel into a first display area and a second display area during a multi-frequency mode; driving the first display area at a first driving frequency and driving the second display area at a second driving frequency; determining whether a still image and a moving image are simultaneously displayed in the first display area; and changing the operation mode to a normal mode when the duration of the still image reaches a predetermined time.

[0022] In an embodiment, the method may further include: changing the operating mode to a normal mode when the average brightness of the still image displayed in the first display area is higher than the reference brightness.

[0023] In an embodiment, changing the operation mode to normal mode may include: determining whether the average brightness of the still image displayed in the first display area is higher than the reference brightness, and when the average brightness of the still image is higher than the reference brightness and the duration of the still image reaches a predetermined time, changing the operation mode to normal mode.

[0024] In one embodiment, changing the operating mode to the normal mode may include: determining whether the still image displayed in the first display area is the worst pattern, and changing the operating mode to the normal mode when the still image is the worst pattern and the duration of the still image reaches a predetermined time.

[0025] In an embodiment, changing the operating mode to a normal mode may include: determining whether the still image displayed in the first display area is the worst pattern, determining whether the display area of ​​the still image is greater than a reference area, and when the still image displayed in the first display area is the worst pattern and the display area of ​​the still image is greater than the reference area, changing the second driving frequency according to the duration of the still image.

[0026] In an embodiment, changing the second driving frequency may include: changing the second driving frequency to a first intermediate frequency when the duration of the still image reaches a first reference time, and changing the second driving frequency to a second intermediate frequency when the duration of the still image reaches a second reference time, wherein the second reference time may be greater than the first reference time, and the second intermediate frequency may be higher than the first intermediate frequency.

[0027] In an embodiment, changing the operation mode to the normal mode may include: changing the operation mode to the normal mode when the duration of the still image reaches a third reference time, wherein the third reference time may be greater than the second reference time.

[0028] In an embodiment, when the ratio of the length of the still image in the first direction to the length of the first display area in the first direction is equal to or greater than a predetermined value, changing the second driving frequency can determine that the display area of ​​the still image is greater than the reference area. Attached Figure Description

[0029] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0030] Figure 1 This is a perspective view of an embodiment of a display device according to the present invention;

[0031] Figure 2A and Figure 2B This is a perspective view of an embodiment of a display device according to the present invention;

[0032] Figure 3A It is a view used to describe the operation of the display device in normal mode;

[0033] Figure 3B It is a view used to describe the operation of a display device in multi-frequency mode;

[0034] Figure 4 This is a block diagram of an embodiment of a display device according to the present invention;

[0035] Figure 5 This is an equivalent circuit diagram of an embodiment of the pixels according to the present invention;

[0036] Figure 6 It is used for explanation Figure 5 The timing diagram of the operations of the pixels shown;

[0037] Figure 7 The scan signal in multi-frequency mode is shown;

[0038] Figure 8 This is a block diagram illustrating an embodiment of the configuration of the drive controller according to the present invention;

[0039] Figure 9 It is a view showing an image displayed on a display device;

[0040] Figure 10 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention;

[0041] Figure 11 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode;

[0042] Figure 12 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode;

[0043] Figure 13 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode;

[0044] Figure 14 It is a view showing an image displayed on a display device;

[0045] Figure 15 It is shown in Figure 14 The view of the afterimages remaining on the display device after the first to third images shown are displayed for an extended period in multi-frequency mode;

[0046] Figure 16 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode;

[0047] Figure 17 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the invention in multi-frequency mode; and

[0048] Figure 18 It is shown in Figure 14 The image shown is a view of the residual images remaining on the display device after the first to third images have been displayed for an extended period of time in multi-frequency mode. Detailed Implementation

[0049] In this disclosure, when an element (or area, layer, portion, etc.) is referred to as being “on”, “connected to”, or “linked to” another element, it means that the element may be directly disposed on / directly connected to / directly linked to the other element, or that a third element may be disposed therein.

[0050] Similar reference numerals refer to similar elements. Additionally, in the drawings, the thickness, proportions, and dimensions of elements are exaggerated for the sake of effective description of the technical content. The term "and / or" includes all combinations of one or more of the associated configurations.

[0051] It will be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of exemplary embodiments of the inventive concept, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. Unless the context clearly indicates otherwise, singular terms may include plural forms.

[0052] Additionally, terms such as "below," "down," "above," and "up" are used to describe the relationships of the configurations shown in the accompanying drawings. These terms are used as relative concepts and are described with reference to the directions indicated in the drawings.

[0053] It should be understood that the terms “comprising” or “having” are intended to indicate the presence of the features, integers, steps, operations, elements, components or combinations thereof stated in this disclosure, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components or combinations thereof.

[0054] Given the measurements discussed and the errors associated with the measurement of a particular quantity (i.e., limitations of the measurement system), the terms “about” or “approximately” as used herein include the stated value and mean within an acceptable range of deviation for a particular value as determined by one of ordinary skill in the art. For example, “about” can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value.

[0055] 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 the inventive concept pertains. It will also be understood that terms defined in common dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the relevant field, and not in an ideal or overly formal sense, except where they are expressly defined herein.

[0056] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings.

[0057] Figure 1 This is a perspective view of an embodiment of a display device according to the present invention.

[0058] Reference Figure 1As an embodiment of the display device DD according to the present invention, a portable terminal is shown. The portable terminal may include a tablet personal computer (“PC”), a smartphone, a personal digital assistant (“PDA”), a portable multimedia player (“PMP”), a game console, a watch-type electronic device, etc. However, the present invention is not limited thereto. Embodiments of the present invention can be used in large electronic devices such as televisions or external advertising boards, and also in small and medium-sized electronic devices such as personal computers, laptop computers, kiosks, vehicle navigation system units, and cameras. It should be understood that these are merely embodiments and can be adopted in other electronic devices without departing from the concept of the present invention.

[0059] like Figure 1 As shown, the display surface displaying the first image IM1 and the second image IM2 is parallel to the plane defined by the first direction DR1 and the second direction DR2. The display device DD includes a plurality of areas separated on the display surface. The display surface includes a display area DA for displaying the first image IM1 and the second image IM2 and a non-display area NDA adjacent to the display area DA. The non-display area NDA may also be referred to as a border area. In an embodiment, the display area DA may have a quadrilateral shape. The non-display area NDA surrounds the display area DA. Additionally, although not shown, as an example, the display device DD may include a partially curved shape. As a result, one area of ​​the display device DD may have a curved shape.

[0060] The display area DA of the display device DD includes a first display area DA1 and a second display area DA2. In a predetermined application, a first image IM1 may be displayed in the first display area DA1, and a second image IM2 may be displayed in the second display area DA2. In an embodiment, for example, the first image IM1 may be a moving image, and the second image IM2 may be a still image or text information with a long changing period.

[0061] In this embodiment, the display device DD can drive the first display area DA1, which displays moving images, at a normal frequency, and can drive the second display area DA2, which displays still images, at a frequency lower than the normal frequency. The display device DD can reduce power consumption by lowering the driving frequency of the second display area DA2.

[0062] The size of each of the first display area DA1 and the second display area DA2 can be a predetermined size and can be changed by an application. In an embodiment, when the first display area DA1 displays a still image and the second display area DA2 displays a moving image, the first display area DA1 can be driven at a lower frequency, and the second display area DA2 can be driven at a normal frequency. Furthermore, the display areas DA can be divided into three or more display areas, and the driving frequency of each display area can be determined according to the type of image (still image or moving image) displayed in each display area.

[0063] Figure 2A and Figure 2B This is a perspective view of an embodiment of the display device DD2 according to the present invention. Figure 2A The display device DD2 in its unfolded state is shown, and Figure 2B The display device DD2 is shown in its folded state.

[0064] like Figure 2A and Figure 2B As shown, the display device DD2 includes a display area DA and a non-display area NDA. The display device DD2 can display images through the display area DA. When the display device DD2 is in an unfolded state, the display area DA may include a plane defined by a first direction DR1 and a second direction DR2. The thickness direction of the display device DD2 may be parallel to a third direction DR3 that intersects with the first direction DR1 and the second direction DR2. Therefore, the front surface (or upper surface) and rear surface (or lower surface) of the components constituting the display device DD2 may be defined based on the third direction DR3. The non-display area NDA may also be referred to as a border area. In an embodiment, the display area DA may have a quadrilateral shape. The non-display area NDA surrounds the display area DA.

[0065] The display area DA may include a first non-folding area NFA1, a folding area FA, and a second non-folding area NFA2. The folding area FA may be bent about a folding axis FX extending along a first direction DR1.

[0066] When the display device DD2 is folded, the first non-folded area NFA1 and the second non-folded area NFA2 can face each other. Therefore, in the fully folded state, the display area DA is not exposed to the outside, which can also be referred to as inward folding. However, this is only an example. The operation of the display device DD2 is not limited to this.

[0067] In embodiments of the present invention, for example, when the display device DD2 is folded, the first non-folding area NFA1 and the second non-folding area NFA2 can face away from each other. Therefore, in the folded state, the first non-folding area NFA1 can be exposed to the outside, which can also be referred to as outward folding.

[0068] Display device DD2 can perform either an inward folding operation or an outward folding operation. In an alternative embodiment, display device DD2 can perform both an inward folding operation and an outward folding operation. In this case, the same area of ​​display device DD2, for example, the folding area FA, can be folded inward and outward. In an alternative embodiment, some areas of display device DD2 can be folded inward, and other areas of display device DD2 can be folded outward.

[0069] exist Figure 2A and Figure 2BThe diagram shows one folded area and two non-folded areas. However, the number of folded and non-folded areas is not limited to this. In an embodiment, for example, the display device DD2 may include more than two non-folded areas and multiple folded areas disposed between adjacent non-folded areas.

[0070] exist Figure 2A and Figure 2B In the diagram, the folding axis FX is shown parallel to the minor axis of the display device DD2, but the invention is not limited thereto. In embodiments, the folding axis FX may extend along the major axis of the display device DD2 (e.g., a direction parallel to the second direction DR2). In this case, for example, the first non-folding region NFA1, the folding region FA, and the second non-folding region NFA2 may be arranged sequentially along the first direction DR1.

[0071] In the display area DA of the display device DD2, multiple display areas DA1 and DA2 can be defined. Figure 2A The image shows two display areas, DA1 and DA2. However, the number of display areas DA1 and DA2 is not limited to this.

[0072] Multiple display areas DA1 and DA2 may include a first display area DA1 and a second display area DA2. In an embodiment, for example, the first display area DA1 may be an area displaying a first image IM1, and the second display area DA2 may be an area displaying a second image IM2. However, the invention is not limited thereto. In an embodiment, for example, the first image IM1 may be a moving image, and the second image IM2 may be a still image or an image with a long changing period (text information, etc.).

[0073] The display device DD2 in this embodiment can operate differently depending on the operating mode. The operating mode may include a normal mode and a multi-frequency mode. In normal mode, the display device DD2 can drive both the first display area DA1 and the second display area DA2 at a normal frequency. In multi-frequency mode, the display device DD2 in this embodiment can drive the first display area DA1 displaying the first image IM1 at a first driving frequency, and can drive the second display area DA2 displaying the second image IM2 at a second driving frequency lower than the normal frequency. In this embodiment, the first driving frequency may be the same as the normal frequency.

[0074] The size of each of the first display area DA1 and the second display area DA2 can be predetermined and can be changed by an application. In an embodiment, the first display area DA1 may correspond to a first non-folding area NFA1, and the second display area DA2 may correspond to a second non-folding area NFA2. Additionally, a first portion of the folding area FA may correspond to the first display area DA1, and a second portion of the folding area FA may correspond to the second display area DA2.

[0075] In an embodiment, the entire folded area FA may correspond to either the first display area DA1 or the second display area DA2.

[0076] In this embodiment, the first display area DA1 may correspond to a first portion of the first non-folded area NFA1, and the second display area DA2 may correspond to a second portion of the first non-folded area NFA1, the folded area FA, and the second non-folded area NFA2. That is, the area of ​​the first display area DA1 may be smaller than the area of ​​the second display area DA2.

[0077] In this embodiment, the first display area DA1 may correspond to the first non-folded area NFA1, the folded area FA, and the first portion of the second non-folded area NFA2, and the second display area DA2 may correspond to the second portion of the second non-folded area NFA2. That is, the area of ​​the second display area DA2 may be smaller than the area of ​​the first display area DA1.

[0078] like Figure 2B As shown, when the folded area FA is in a folded state, the first display area DA1 can correspond to the first non-folded area NFA1, and the second display area DA2 can correspond to the second non-folded area NFA2.

[0079] exist Figure 2A and Figure 2B In the illustration, a display device DD2 having one folding area is shown as an embodiment of a display device. However, the invention is not limited thereto. In the embodiments, for example, the invention can be applied to display devices including two or more folding areas, rollable display devices, slidable display devices, etc.

[0080] In the following description, Figure 1 The display device DD shown will be described as an example. However, the same description applies to... Figure 2A and Figure 2B The display device DD2 shown is shown.

[0081] Figure 3A It is a view used to describe the operation of the display device in normal mode. Figure 3B It is a view used to describe the operation of a display device in multi-frequency mode.

[0082] Reference Figure 3A The first image IM1 to be displayed in the first display area DA1 may be a moving image, and the second image IM2 to be displayed in the second display area DA2 may be a still image or an image with a long change cycle (e.g., a keyboard used for game operation). Figure 1 The first image IM1 to be displayed in the first display area DA1 and the second image IM2 to be displayed in the second display area DA2 shown are merely examples. Various images may be displayed in the display device DD.

[0083] In normal NFM mode, the driving frequency of the first display area DA1 and the second display area DA2 of the display device DD is the normal frequency. In an embodiment, the normal frequency may be approximately 120 Hz. In normal NFM mode, for example, in the first display area DA1 and the second display area DA2 of the display device DD, the image from the first frame F1 to the 120th frame F120 can be displayed for one second.

[0084] Reference Figure 3B In Multi-Frequency Mode (MFM), the display device DD can set the driving frequency of the first display area DA1, which displays the first image IM1 (a moving image), to a first driving frequency, and can set the driving frequency of the second display area DA2, which displays the second image IM2 (a still image), to a second driving frequency lower than the first driving frequency. When the normal frequency is approximately 120 Hz, the first driving frequency can be approximately 120 Hz, and the second driving frequency can be approximately 1 Hz. The first and second driving frequencies can be varied. In an embodiment, for example, the first driving frequency can be approximately 144 Hz, which is higher than the normal frequency, and the second driving frequency can be either approximately 30 Hz or approximately 10 Hz, which is lower than the normal frequency.

[0085] When the first driving frequency is 120Hz and the second driving frequency is 1Hz in multi-frequency mode MFM, the first image IM1 is displayed for one second in each of the first frames F1 to F120 in the first display area DA1 of the display device DD. In the second display area DA2, the second image IM2 may be displayed only in the first frame F1, and no image may be displayed in the remaining frames F2 to F120. The operation of the display device DD in multi-frequency mode MFM will be described in detail later.

[0086] Figure 4 This is a block diagram of an embodiment of a display device according to the present invention.

[0087] Reference Figure 4 The display device DD includes a display panel DP, a drive controller 100, a data drive circuit 200, and a voltage generator 300.

[0088] The drive controller 100 receives the image signal RGB and the control signal CTRL. The drive controller 100 generates an image data signal DATA by converting the data format of the image signal RGB to meet the interface specifications of the data drive circuit 200. The drive controller 100 outputs a scan control signal SCS, a data control signal DCS, and a light emission control signal ECS.

[0089] The data drive circuit 200 receives a data control signal DCS and an image data signal DATA from the drive controller 100. The data drive circuit 200 converts the image data signal DATA into a data signal and outputs the data signal to a plurality of data lines DL1 to DLm, which will be described later, where m is a natural number. The data signal is an analog voltage corresponding to the grayscale value of the image data signal DATA.

[0090] Voltage generator 300 generates the voltages required for the operation of display panel DP. In this embodiment, voltage generator 300 generates a first driving voltage ELVDD, a second driving voltage ELVSS, a first initialization voltage VINT1, and a second initialization voltage VINT2.

[0091] The display panel DP includes scan lines GIL1 to GILn, GCL1 to GCLn and GWL1 to GWLn+1, light emission control lines EML1 to EMLn, data lines DL1 to DLm, and pixels PX, where n is a natural number. The display panel DP may also include a scan drive circuit SD and a light emission drive circuit EDC. In an embodiment, the scan drive circuit SD is arranged on a first side of the display panel DP (e.g., ...). Figure 4 On the left side of the middle. Scan lines GIL1 to GILn, GCL1 to GCLn and GWL1 to GWLn+1 extend from the scan drive circuit SD along the first direction DR1.

[0092] The light emission drive circuit EDC is arranged on the second side of the display panel DP (e.g., Figure 4 On the right side of the image. The optical emission control lines EML1 to EMLn extend from the optical emission drive circuit EDC in the opposite direction to the first direction DR1.

[0093] Scan lines GIL1 to GILn, GCL1 to GCLn, and GWL1 to GWLn+1, as well as optical emission control lines EML1 to EMLn, are arranged spaced apart from each other on the second direction DR2. Data lines DL1 to DLm extend from the data drive circuit 200 in the opposite direction to the second direction DR2 and are arranged spaced apart from each other on the first direction DR1.

[0094] exist Figure 4 In the example shown, the scan drive circuit SD and the light emission drive circuit EDC are arranged facing each other with the pixel PX between them, but the invention is not limited thereto. In embodiments, for example, the scan drive circuit SD and the light emission drive circuit EDC may be configured to be adjacent to either the first side or the second side of the display panel DP. In embodiments, the scan drive circuit SD and the light emission drive circuit EDC may be formed as a single circuit.

[0095] Multiple pixels PX are electrically connected to scan lines GIL1 to GILn, GCL1 to GCLn, and GWL1 to GWLn+1, light emission control lines EML1 to EMLn, and data lines DL1 to DLm, respectively. Each of the multiple pixels PX can be electrically connected to four scan lines and one light emission control line. In an embodiment, as... Figure 4 As shown, the pixel PX in the first row can be connected to scan lines GIL1, GCL1, GWL1, and GWL2, as well as the light emission control line EML1. Additionally, for example, the pixel PX in the second row can be connected to scan lines GIL2, GCL2, GWL2, and GWL3, as well as the light emission control line EML2.

[0096] Each of the multiple pixels PX includes a light-emitting diode (ED) (see reference). Figure 5 ) and the pixel circuit PXC (refer to) that controls the light emission of the light-emitting diode ED. Figure 5 The pixel circuit (PXC) may include one or more transistors and one or more capacitors. The scan drive circuit (SD) and the light emission drive circuit (EDC) may include transistors formed using the same process as the pixel circuit (PXC).

[0097] Each of the multiple pixels PX receives a first driving voltage ELVDD, a second driving voltage ELVSS, a first initialization voltage VINT1, and a second initialization voltage VINT2.

[0098] The scan drive circuit SD receives the scan control signal SCS from the drive controller 100. In response to the scan control signal SCS, the scan drive circuit SD outputs scan signals to scan lines GIL1 to GILn, GCL1 to GCLn, and GWL1 to GWLn+1. The circuit configuration and operation of the scan drive circuit SD will be described in detail later.

[0099] The drive controller 100 in this embodiment can divide the display panel DP into a first display area DA1 based on the image signal RGB (refer to...). Figure 1 ) and the second display area DA2 (refer to) Figure 1 The drive controller 100 can set the driving frequency of the first display area DA1 and the driving frequency of the second display area DA2. In an embodiment, for example, in normal mode, the drive controller 100 drives each of the first display area DA1 and the second display area DA2 at a normal frequency (e.g., about 120 Hz). In multi-frequency mode, the drive controller 100 can drive the first display area DA1 at a first driving frequency (e.g., about 120 Hz) and can drive the second display area DA2 at a low frequency (e.g., about 1 Hz).

[0100] Figure 5 This is an equivalent circuit diagram of an embodiment of the pixels according to the present invention.

[0101] Figure 5 It shows the connection to Figure 4 The diagram shows the equivalent circuit diagram of pixel PXij of the i-th data line DLi among data lines DL1 to DLm, the j-th scan lines GILj, GCLj, and GWLj among scan lines GIL1 to GCLn and GWL1 to GWLn+1, and the (j+1)-th scan line GWLj+1, and the j-th light emission control line EMLj among light emission control lines EML1 to EMLn. Here, i and j can be natural numbers.

[0102] Figure 4 Each of the plurality of pixels PX shown may have the same as Figure 5 The circuit configuration shown in the equivalent circuit diagram of pixel PXij is the same as that shown in this embodiment. In the pixel circuit PXC of pixel PXij, the third transistor T3 and the fourth transistor T4 among the first transistor T1 to the seventh transistor T7 are each n-type transistors with oxide semiconductor as the semiconductor layer, and each of the first transistor T1, the second transistor T2, the fifth transistor T5, the sixth transistor T6, and the seventh transistor T7 is a p-type transistor with a low-temperature polycrystalline silicon (“LTPS”) semiconductor layer. However, the invention is not limited thereto. All of the first transistors T1 to the seventh transistor T7 may be p-type transistors or n-type transistors. In another embodiment, at least one of the first transistors T1 to the seventh transistor T7 may be an n-type transistor, and the rest of the first transistors T1 to the seventh transistor T7 may be p-type transistors. Moreover, the circuit configuration of the pixel according to the invention is not limited to... Figure 5 The configuration shown. Figure 5 The pixel circuit PXC shown is merely an example, and the configuration of the pixel circuit PXC can be modified and implemented.

[0103] Reference Figure 5 In this embodiment, a pixel PXij of the display device includes a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, a sixth transistor T6, and a seventh transistor T7, a capacitor Cst, and at least one light-emitting diode ED. In this embodiment, a pixel PXij including one light-emitting diode ED will be described as an example.

[0104] In the following text, for ease of description, the i-th data line DLi may be referred to as data line DLi, the j-th scan lines GILj, GCLj, and GWLj may be referred to as scan lines GILj, GCLj, and GWLj, the (j+1)-th scan line GWLj+1 may be referred to as scan line GWLj+1, and the j-th light emission control line EMLj may be referred to as light emission control line EMLj. Scan lines GILj, GCLj, GWLj, and GWLj+1 may transmit scan signals GIj, GCj, GWj, and GWj+1, respectively, and the light emission control line EMLj may transmit the light emission signal EMj. Data line DLi transmits data signal Di. Data signal Di may have an input to the display device DD (refer to...). Figure 4 The image signal RGB corresponds to the voltage level. The first driving voltage line VL1, the second driving voltage line VL2, the third driving voltage line VL3, and the fourth driving voltage line VL4 can respectively transmit the first driving voltage ELVDD, the second driving voltage ELVSS, the first initialization voltage VINT1, and the second initialization voltage VINT2.

[0105] The first transistor T1 includes a first electrode connected to the first drive voltage line VL1 via a fifth transistor T5, a second electrode electrically connected to the anode of the light-emitting diode ED via a sixth transistor T6, and a gate electrode connected to one end of the capacitor Cst. The first transistor T1 can receive the data signal Di transmitted by the data line DLi according to the switching operation of the second transistor T2, and supply the drive current Id to the light-emitting diode ED.

[0106] The second transistor T2 includes a first electrode connected to the data line DLi, a second electrode connected to the first electrode of the first transistor T1, and a gate electrode connected to the scan line GWLj. The second transistor T2 can be turned on according to the scan signal GWj received through the scan line GWLj, so as to transmit the data signal Di transmitted from the data line DLi to the first electrode of the first transistor T1.

[0107] The third transistor T3 includes a first electrode connected to the gate electrode of the first transistor T1, a second electrode connected to the second electrode of the first transistor T1, and a gate electrode connected to the scan line GCLj. The third transistor T3 can be turned on according to the scan signal GCj received through the scan line GCLj to connect the gate electrode and the second electrode of the first transistor T1, so as to connect the first transistor T1 in the form of a diode.

[0108] The fourth transistor T4 includes a first electrode connected to the gate electrode of the first transistor T1, a second electrode connected to a third drive voltage line VL3 through which the first initialization voltage VINT1 is transmitted, and a gate electrode connected to the scan line GILj. The fourth transistor T4 can be turned on according to the scan signal GIj received through the scan line GILj to transmit the first initialization voltage VINT1 to the gate electrode of the first transistor T1, so as to perform an initialization operation to initialize the voltage of the gate electrode of the first transistor T1.

[0109] The fifth transistor T5 includes a first electrode connected to the first driving voltage line VL1, a second electrode connected to the first electrode of the first transistor T1, and a gate electrode connected to the light emission control line EMLj.

[0110] The sixth transistor T6 includes a first electrode connected to the second electrode of the first transistor T1, a second electrode connected to the anode of the light-emitting diode ED, and a gate electrode connected to the light emission control line EMLj.

[0111] The fifth transistor T5 and the sixth transistor T6 are simultaneously turned on according to the light emission signal EMj received through the light emission control line EMLj, and as a result, the first drive voltage ELVDD can be compensated by the first transistor T1 connected in the form of a diode and can be transmitted to the light-emitting diode ED.

[0112] The seventh transistor T7 includes a first electrode connected to the second electrode of the sixth transistor T6, a second electrode connected to the fourth voltage line VL4, and a gate electrode connected to the scan line GWLj+1. The seventh transistor T7 is turned on according to the scan signal GWj+1 received through the scan line GWLj+1, so that the current of the anode of the light-emitting diode ED is bypassed to the fourth voltage line VL4.

[0113] As described above, one end of capacitor Cst is connected to the gate electrode of the first transistor T1, and the other end is connected to the first driving voltage line VL1. The cathode of the light-emitting diode ED can be connected to the second driving voltage line VL2, which transmits the second driving voltage ELVSS. The structure of pixel PXij in the embodiment is not limited to... Figure 5 The structure shown is illustrated. The number of transistors and capacitors included in a pixel PXij, as well as their interconnections, can be modified in various ways.

[0114] Figure 6 It is used for explanation Figure 5 The timing diagram shows the operation of the pixels shown. (Refer to...) Figure 5 and Figure 6 This section will describe an embodiment of the operation of the display device.

[0115] Reference Figure 5 and Figure 6During the initialization period within a frame F, a high-level scan signal GIj is supplied through scan line GILj. In response to the high-level scan signal GIj, the fourth transistor T4 is turned on, and through the fourth transistor T4, the first initialization voltage VINT1 is transmitted to the gate electrode of the first transistor T1 to initialize the first transistor T1.

[0116] Next, when a high-level scan signal GCj is supplied via scan line GCLj during the data programming and compensation period, the third transistor T3 is turned on. The first transistor T1 is connected as a diode via the turned-on third transistor T3 and is forward biased. Additionally, the second transistor T2 is turned on via a low-level scan signal GWj. Then, a compensation voltage Di-Vth, obtained by subtracting the threshold voltage Vth of the first transistor T1 from the data signal Di supplied via data line DL1, is applied to the gate electrode of the first transistor T1. That is, the gate voltage applied to the gate electrode of the first transistor T1 can be the compensation voltage Di-Vth.

[0117] A first driving voltage ELVDD and a compensation voltage Di-Vth are applied to the two ends of the capacitor Cst, respectively, and a charge corresponding to the voltage difference between the two ends can be stored in the capacitor Cst.

[0118] The seventh transistor T7 is turned on by being supplied with a low-level scan signal GWj+1 via scan line GWLj+1. A portion of the drive current Id can flow out through the seventh transistor T7 as a bypass current Ibp.

[0119] When the light-emitting diode ED emits light even during the flow of the minimum current of the first transistor T1 used to display a black image as the drive current Id, the black image is not properly displayed. Accordingly, in the embodiment of the invention, the seventh transistor T7 in pixel PXij can guide a portion of the minimum current of the first transistor T1 as a bypass current Ibp to a current path other than the current path on the side of the light-emitting diode ED. Here, the minimum current of the first transistor T1 refers to the current under the condition that the first transistor T1 is turned off because the gate-source voltage Vgs of the first transistor T1 is less than the threshold voltage Vth. In this way, the minimum drive current (e.g., about 10 picoamperes (pA) or less) under the condition that the first transistor T1 is turned off is transmitted to the light-emitting diode ED and displayed as an image of black brightness. When the minimum drive current used to display a black image flows, the effect of bypassing the bypass current Ibp is significant. However, when a large drive current is used to display an image such as a normal image or a white image, the effect of the bypass current Ibp is small. Accordingly, when the drive current Id used to display a black image flows, the luminous current Ied of the light-emitting diode ED, which is the result of subtracting the bypass current Ibp flowing through the seventh transistor T7 from the drive current Id, can have a minimum current amount that reaches a certain level in order to reliably display a black image. Accordingly, the seventh transistor T7 can be used to achieve an image with correct black brightness, thereby improving contrast. In this embodiment, the bypass signal is a low-level scan signal GWj+1, but embodiments of the present invention are not limited to this.

[0120] Next, during the light emission period, the light emission signal EMj supplied from the light emission control line EMLj changes from a high level to a low level. During the light emission period, the fifth transistor T5 and the sixth transistor T6 are turned on by the low-level light emission signal EMj. Then, a drive current Id is generated corresponding to the voltage difference between the gate voltage of the gate electrode of the first transistor T1 and the first drive voltage ELVDD, and the drive current Id is supplied to the light-emitting diode ED through the sixth transistor T6 so that the light emission current Ied flows in the light-emitting diode ED.

[0121] Figure 7 The scan signals GI1 to GI3840 in multi-frequency mode are shown.

[0122] Reference Figure 7 In multi-frequency mode, the frequency of scan signals GI1 to GI1920 is approximately 120 Hz, and the frequency of scan signals GI1921 to GI3840 is approximately 1 Hz.

[0123] In an embodiment, for example, scan signals GI1 to GI1920 correspond to Figure 1The first display area DA1 of the display device DD shown is shown, and the scan signals GI1921 to GI3840 correspond to... Figure 1 The second display area DA2 of the display device DD shown.

[0124] Scan signals GI1 to GI1920 can be activated as high in each of the first frame F1 to the 120th frame F120, and scan signals GI1921 to GI3840 can be activated as high only in the first frame F1.

[0125] Therefore, the first display area DA1, which displays moving images, can be driven by scan signals GI1 to GI1920 at a normal frequency (e.g., about 120 Hz), and the second display area DA2, which displays still images, can be driven by scan signals GI1921 to GI3840 at a low frequency (e.g., about 1 Hz). Since the second display area DA2, which only displays still images, is driven at a low frequency, it can be used without a display device DD (refer to...). Figure 1 To reduce power consumption in the event of a deterioration in display quality.

[0126] Figure 7 Only scan signals GI1 to GI3840 are shown. However, the scan drive circuit SD (see reference) Figure 4 ) and light emission drive circuit EDC (refer to Figure 4 It can also generate scan signals GC1 to GC3840 and GW1 to GW3841 and optical emission signals EM1 to EM3840 in a similar manner to generate scan signals GI1 to GI3840.

[0127] Figure 8 This is a block diagram illustrating an embodiment of the configuration of the drive controller according to the present invention.

[0128] Reference Figure 4 and Figure 8 The drive controller 100 includes a frequency mode determination unit 110 and a signal generator 120. The frequency mode determination unit 110 determines the frequency mode in response to the image signal RGB and the control signal CTRL, and outputs a mode signal MD corresponding to the determined frequency mode.

[0129] The signal generator 120 receives an image signal RGB, a control signal CTRL, and a mode signal MD from the frequency mode determination unit 110. In response to the image signal RGB, the control signal CTRL, and the mode signal MD, the signal generator 120 outputs an image data signal DATA, a data control signal DCS, a light emission control signal ECS, and a scan control signal SCS.

[0130] When the mode signal MD indicates the normal mode, the signal generator 120 can output a signal to drive the first display area DA1 at the normal frequency (see reference). Figure 1 ) and the second display area DA2 (refer to) Figure 1 Each of these signals consists of an image data signal DATA, a data control signal DCS, an optical emission control signal ECS, and a scan control signal SCS. Figure 4 The data driving circuit 200, the scan driving circuit SD, and the light emission driving circuit EDC shown operate in response to the image data signal DATA, the data control signal DCS, the light emission control signal ECS, and the scan control signal SCS, so that the image is displayed on the display panel DP.

[0131] When the mode signal MD represents a multi-frequency mode, the signal generator 120 can output image data signal DATA, data control signal DCS, light emission control signal ECS, and scan control signal SCS for driving the first display area DA1 at a first driving frequency and the second display area DA2 at a second driving frequency. In one embodiment, the first driving frequency may be the same as the normal frequency. In another embodiment, the first driving frequency may be a frequency higher than the normal frequency.

[0132] The operation of the frequency mode determination unit 110 will be described in detail later.

[0133] Figure 9 It is a view showing an image displayed on a display device.

[0134] Reference Figure 9 The display area DA may include a first display area DA1 and a second display area DA2. A first image IM1 and a third image IM3 may be displayed in the first display area DA1, and a second image IM2 may be displayed in the second display area DA2. In an embodiment, the first image IM1 may be a moving image, and the second image IM2 and the third image IM3 may be still images. The second image IM2 and the third image IM3 may be related images or may be independent images. Figure 9 In the example shown, the second image IM2 includes an icon for running the application, and the third image IM3 includes information such as the date, time, and weather. However, the second image IM2 and the third image IM3 are not limited to this.

[0135] Reference Figure 8 and Figure 9The frequency mode determination unit 110 receives image signals RGB and control signals CTRL, determines an operation mode based on the image signals RGB and CTRL, and outputs a mode signal MD corresponding to the determined operation mode. In an embodiment, for example, when the image signal RGB corresponding to the first display area DA1 includes a moving image and the image signal RGB corresponding to the second display area DA2 is a still image, the frequency mode determination unit 110 changes the operation mode to a multi-frequency mode and outputs the mode signal MD. Not only when the image signal RGB corresponding to the first display area DA1 includes a moving image, but also when the image signal RGB corresponding to the first display area DA1 includes both a moving image and a still image, the frequency mode determination unit 110 can determine the operation mode as a multi-frequency mode when the image signal RGB corresponding to the second display area DA2 is a still image.

[0136] When the mode signal MD represents a multi-frequency mode, the signal generator 120 can output image data signal DATA, data control signal DCS, light emission control signal ECS and scan control signal SCS for driving the first display area DA1 at a first driving frequency and driving the second display area DA2 at a second driving frequency.

[0137] Therefore, the first image IM1, which is a moving image, and the third image IM3, which is a still image, can be displayed in the first display area DA1 at the first driving frequency, and the second image IM2 can be displayed in the second display area DA2 at the second driving frequency.

[0138] After a predetermined period of time has elapsed in a multi-frequency mode where the first display area DA1 is driven at a first driving frequency and the second display area DA2 is driven at a second driving frequency, a new image (e.g., an image with high brightness) can be displayed in the first display area DA1 and the second display area DA2. At this time, depending on the duration of the multi-frequency mode, the afterimages of the third image IM3 of the first display area DA1 and the second image IM2 of the second display area DA2 can affect the new image. In particular, as the duration of the multi-frequency mode becomes longer and the brightness of the still image becomes higher, the afterimage phenomenon becomes more severe.

[0139] In particular, such as in Figure 9 In the example shown, the afterimage phenomenon caused by the third image IM3 of the first display area DA1 driven at the first driving frequency can be more severe than the afterimage phenomenon caused by the second image IM2 of the second display area DA2 driven at the second driving frequency. When the second image IM2 and the third image IM3 are related images, the boundary between the first display area DA1 and the second display area DA2 can be visually identified.

[0140] When a still image is displayed for a long period of time in multi-frequency mode and / or the average brightness of the still image is higher than the reference brightness, the frequency mode determination unit 110 in the embodiment can terminate the multi-frequency mode and operate in normal mode.

[0141] Figure 10 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention.

[0142] Reference Figure 8 , Figure 9 and Figure 10 The frequency mode determination unit 110 of the drive controller 100 can initially (for example, after power-on) set the operating mode to normal mode.

[0143] The frequency mode determination unit 110 determines the frequency mode in response to the image signal RGB and the control signal CTRL. In an embodiment, for example, when a portion of the image signal RGB of a frame (e.g., the image signal corresponding to the first display area DA1) is a moving image and another portion (e.g., the image signal corresponding to the second display area DA2) is a still image (operation S100), the frequency mode determination unit 110 changes the operation mode to a multi-frequency mode and outputs a mode signal MD corresponding to the determined frequency mode (operation S110).

[0144] Figure 11 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode.

[0145] Reference Figure 8 , Figure 9 and Figure 11 During multi-frequency mode, the first display area DA1 can be driven by a first driving frequency, and the second display area DA2 can be driven by a second driving frequency lower than the first driving frequency.

[0146] The signal generator 120 can simultaneously display moving and still images in the first display area DA1 in response to the image signal RGB and the control signal CTRL during multi-frequency mode.

[0147] The frequency mode determination unit 110 of the drive controller 100 determines whether a still image is displayed in the first display area DA1 in the multi-frequency mode (operation S200). That is, the frequency mode determination unit 110 determines whether the image signal RGB corresponding to the first display area DA1 includes both moving images and still images.

[0148] like Figure 9As shown, if the image signal RGB corresponding to the first display area DA1 includes both the first image IM1 as a moving image and the third image IM3 as a still image, the frequency mode determination unit 110 calculates the average brightness B of the still image (operation S210).

[0149] The frequency mode determination unit 110 determines whether the average brightness B of the still image is higher than the reference brightness BT (or threshold brightness) (operation S220). In an embodiment, the average brightness B of the still image may be the average brightness of the third image IM3 displayed in the first display area DA1. In an embodiment, the average brightness B of the still image may be the average brightness of the third image IM3 displayed in the first display area DA1 and the second image IM2 displayed in the second display area DA2.

[0150] When the average brightness B of the still image is lower than the reference brightness BT, the frequency mode determination unit 110 maintains the operation mode in multi-frequency mode. When the average brightness B of the still image is lower than the reference brightness BT, even if the still image is displayed for a long period and then switched to a new image, the effect caused by afterimages may not be significant. Therefore, when the average brightness B of the still image is lower than the reference brightness BT, the frequency mode determination unit 110 maintains multi-frequency mode. As a result, the second display area DA2 is driven at a second driving frequency, thereby reducing power consumption.

[0151] When the average brightness B of the still image is higher than the reference brightness BT, the frequency mode determination unit 110 changes the operation mode to normal mode (operation S230). When the average brightness B of the still image is higher than the reference brightness BT, when the still image is displayed for a long period of time and then switched to a new image, there may be a difference in the degree of afterimage between the first display area DA1 and the second display area DA2. When the afterimage is displayed differently in the first display area DA1 and the second display area DA2, the afterimage can be more easily recognized by the user visually, and the boundary between the first display area DA1 and the second display area DA2 can be visually recognized by the user. Therefore, when the average brightness B of the still image is higher than the reference brightness BT, the frequency mode determination unit 110 changes the operation mode to normal mode so as to drive the first display area DA1 and the second display area DA2 at a normal frequency. As a result, the afterimage deviation between the first display area DA1 and the second display area DA2 can be minimized, and the boundary between the first display area DA1 and the second display area DA2 can be prevented from being visually recognized by the user.

[0152] Figure 12 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode.

[0153] Reference Figure 8 , Figure 9 and Figure 12During multi-frequency mode, the first display area DA1 can be driven by a first driving frequency, and the second display area DA2 can be driven by a second driving frequency lower than the first driving frequency.

[0154] The signal generator 120 can simultaneously display moving and still images in the first display area DA1 in response to the image signal RGB and the control signal CTRL during multi-frequency mode.

[0155] The frequency mode determination unit 110 of the drive controller 100 determines whether a still image is displayed in the first display area DA1 in the multi-frequency mode (operation S250). That is, the frequency mode determination unit 110 determines whether the image signal RGB corresponding to the first display area DA1 includes both moving images and still images.

[0156] like Figure 9 As shown, if the image signal RGB corresponding to the first display area DA1 includes both a first image IM1 as a moving image and a third image IM3 as a still image, the frequency mode determination unit 110 starts counting the display time T of the third image IM3 as a still image (operation S260). Although not shown in the figures, the frequency mode determination unit 110 may include a counter.

[0157] The frequency mode determination unit 110 determines whether the display time T is longer than the predetermined reference time TT (or threshold time) (operation S270).

[0158] When the display time T is not longer than the predetermined reference time TT, the frequency mode determination unit 110 maintains the multi-frequency mode. During the multi-frequency mode, the display time T of the third image IM3, which is a still image, can continue to be counted.

[0159] When the display time T is longer than the predetermined reference time TT, the frequency mode determination unit 110 changes the operation mode to the normal mode and outputs the mode signal MD corresponding to the normal mode (operation S280).

[0160] After a third image IM3, which is a still image, is displayed for a long period of time (e.g., longer than a predetermined reference time TT) in a first display area DA1 driven at a first driving frequency, and a second image IM2, which is a still image, is displayed for a long period of time (e.g., longer than a predetermined reference time TT) in a second display area DA2 driven at a second driving frequency, a new image can be displayed in the first display area DA1 and the second display area DA2. In this case, there may be a difference in the degree of afterimage between the first display area DA1 and the second display area DA2. When the afterimage is displayed differently in the first display area DA1 and the second display area DA2, the afterimage can be more easily recognized by the user visually, and the boundary between the first display area DA1 and the second display area DA2 can be visually recognized by the user. Therefore, when the display time T of the still image is longer than the predetermined reference time TT, the frequency mode determination unit 110 changes the operation mode to a normal mode so as to drive the first display area DA1 and the second display area DA2 at a normal frequency. As a result, the afterimage deviation between the first display area DA1 and the second display area DA2 can be minimized, and the boundary between the first display area DA1 and the second display area DA2 can be prevented from being visually recognized by the user.

[0161] Figure 13 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode.

[0162] Reference Figure 8 , Figure 9 and Figure 13 During multi-frequency mode, the first display area DA1 can be driven by a first driving frequency, and the second display area DA2 can be driven by a second driving frequency lower than the first driving frequency.

[0163] The frequency mode determination unit 110 of the drive controller 100 determines whether a still image is displayed in the first display area DA1 in the multi-frequency mode (operation S300). That is, the frequency mode determination unit 110 determines whether the image signal RGB corresponding to the first display area DA1 includes a still image.

[0164] like Figure 9 As shown, when the image signal RGB corresponding to the first display area DA1 includes both the first image IM1 as a moving image and the third image IM3 as a still image, the frequency mode determination unit 110 calculates the average brightness B of the still image (operation S310).

[0165] The frequency mode determination unit 110 determines whether the average brightness B of the still image is higher than the reference brightness BT (or threshold brightness) (operation S320). In an embodiment, the average brightness B of the still image may be the average brightness of the third image IM3 displayed in the first display area DA1. In an embodiment, the average brightness B of the still image may be the average brightness of the third image IM3 displayed in the first display area DA1 and the second image IM2 displayed in the second display area DA2.

[0166] When the average brightness B of the still image is lower than the reference brightness BT, the frequency mode determination unit 110 maintains the operation mode in multi-frequency mode. When the average brightness B of the still image is lower than the reference brightness BT, even if the still image is displayed for a long period and then switched to a new image, the effect caused by afterimages may not be significant. Therefore, when the average brightness B of the still image is lower than the reference brightness BT, the frequency mode determination unit 110 maintains multi-frequency mode. As a result, the second display area DA2 is driven at a second driving frequency, thereby reducing power consumption.

[0167] When the average brightness B of the still image is higher than the reference brightness BT, the frequency mode determination unit 110 starts counting the display time T of the third image IM3, which is displayed as a still image, during this period (operation S330). Although not shown in the accompanying drawings, the frequency mode determination unit 110 may include a counter.

[0168] The frequency mode determination unit 110 determines whether the display time T is longer than the predetermined reference time TT (or threshold time) (operation S340).

[0169] When the display time T is not longer than the predetermined reference time TT, the frequency mode determination unit 110 maintains the multi-frequency mode. During the multi-frequency mode, the display time T of the third image IM3, which is a still image, can continue to be counted.

[0170] When the display time T is longer than the predetermined reference time TT, the frequency mode determination unit 110 changes the operation mode to the normal mode and outputs the mode signal MD corresponding to the normal mode (operation S350).

[0171] During the display of a third image IM3, which is a still image, in the first display area DA1 driven at a first driving frequency, when the average brightness B of the still image is higher than the reference brightness BT and the display time T of the still image is longer than a predetermined reference time TT, the frequency mode determination unit 110 changes the operation mode to a normal mode so as to drive the first display area DA1 and the second display area DA2 at a normal frequency. As a result, the afterimage deviation between the first display area DA1 and the second display area DA2 can be minimized, and the boundary between the first display area DA1 and the second display area DA2 can be prevented from being visually recognized by the user.

[0172] Figure 14 It is a view showing an image displayed on a display device.

[0173] Reference Figure 14 The display area DA may include a first display area DA1 and a second display area DA2. A first image IM1 and a third image IM3 may be displayed in the first display area DA1, and a second image IM2 may be displayed in the second display area DA2. In an embodiment, the first image IM1 may be a moving image, and the second image IM2 and the third image IM3 may be still images. The second image IM2 and the third image IM3 may be related images or may be independent images.

[0174] exist Figure 14 In the example shown, the second image IM2 and the third image IM3 may each be the worst pattern causing afterimage artifacts when a new image is displayed after the second image IM2 and the third image IM3 have been displayed on the display device for a long period of time. Figure 14 In the second image IM2 and the third image IM3, areas with high brightness and areas with low brightness are arranged in a matrix. The worst pattern causing afterimages is not limited to... Figure 14 The example shown is illustrated. In embodiments, for example, striped patterns, dot patterns, zigzag patterns, etc., may be the worst-case pattern, in which areas with high brightness and areas with low brightness are alternately arranged in a first direction DR1 or a second direction DR2. In alternative embodiments, an image that does not have a predetermined shape but in which areas with high brightness and areas with low brightness appear randomly may be the worst-case pattern.

[0175] Figure 15 It is shown in Figure 14 The image shown is a view of the residual images remaining on the display device after the first to third images have been displayed for an extended period of time in multi-frequency mode.

[0176] Reference Figure 14 and Figure 15 In multi-frequency mode, the first display area DA1 can be driven by the first driving frequency, and the second display area DA2 can be driven by the second driving frequency, which is lower than the first driving frequency.

[0177] exist Figure 14 The first image IM1, the second image IM2, and the third image IM3 shown are displayed in the display area DA for a long period of time in multi-frequency mode, as follows: Figure 15 As shown, a new image (e.g., an image corresponding to grayscale for gray color) can be displayed in the entire display area DA.

[0178] Although an image with the same grayscale (e.g., grayscale for gray color) is displayed throughout the entire display area DA, the image IM3 (refer to) is different. Figure 14The afterimage IM3a caused by the second image IM2 (refer to the image IM3a) is displayed in the first display area DA1, and is also displayed in the second display area DA1. Figure 14 The resulting afterimage IM2a is displayed in the second display area DA2.

[0179] exist Figure 14 In the image, the second image IM2 and the third image IM3 are the same image pattern, but the afterimage IM3a shown in the first display area DA1 and the afterimage IM2a shown in the second display area DA2 are displayed with different brightness. This is because the driving frequency of the first display area DA1 and the second display area DA2 are different in multi-frequency mode. In other words, this means that even when still images of the same grayscale are displayed in the first display area DA1 and the second display area DA2 for a long period of time, the effect of the afterimage varies depending on the driving frequency.

[0180] Figure 16 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode.

[0181] Reference Figure 8 , Figure 14 and Figure 16 During multi-frequency mode, the first display area DA1 can be driven by a first driving frequency, and the second display area DA2 can be driven by a second driving frequency lower than the first driving frequency.

[0182] The frequency mode determination unit 110 of the drive controller 100 determines whether a still image is displayed in the first display area DA1 in the multi-frequency mode (operation S400). That is, the frequency mode determination unit 110 determines whether the image signal RGB corresponding to the first display area DA1 includes a still image.

[0183] like Figure 14 As shown, if the image signal RGB corresponding to the first display area DA1 includes both a first image IM1 as a moving image and a third image IM3 as a still image, the frequency pattern determination unit 110 determines whether the third image IM3 as a still image is the worst pattern (operation S410).

[0184] As described above, when the still image to be displayed in the first display area DA1 corresponds to any one of a predetermined pattern such as a matrix pattern, a stripe pattern, a dot pattern, and a zigzag pattern, which has areas with high brightness and areas with low brightness, the frequency mode determination unit 110 can determine that the still image to be displayed in the first display area DA1 is the worst pattern.

[0185] When the still image to be displayed in the first display area DA1 is not the worst pattern, the frequency mode determination unit 110 maintains the multi-frequency mode.

[0186] When the still image to be displayed in the first display area DA1 is the worst pattern, the frequency pattern determination unit 110 starts counting the display time T of the still image displayed in the first display area DA1 (operation S420). Although not shown in the figures, the frequency pattern determination unit 110 may include a counter.

[0187] The frequency mode determination unit 110 determines whether the display time T is longer than the predetermined reference time TT (or threshold time) (operation S430).

[0188] When the display time T is not longer than the predetermined reference time TT, the frequency mode determination unit 110 maintains the multi-frequency mode. During the multi-frequency mode, the display time T of the third image IM3, which is a still image, can continue to be counted.

[0189] When the display time T is longer than the predetermined reference time TT, the frequency mode determination unit 110 changes the operation mode to the normal mode and outputs the mode signal MD corresponding to the normal mode (operation S440).

[0190] After the third image IM3, which is the worst pattern, is displayed for a long period of time (e.g., longer than the predetermined reference time TT) in the first display area DA1 driven at the first driving frequency, and the second image IM2, which is a still image, is displayed for a long period of time (e.g., longer than the predetermined reference time TT) in the second display area DA2 driven at the second driving frequency, a new image can be displayed in the first display area DA1 and the second display area DA2. In this case, there may be a difference in the degree of afterimage between the first display area DA1 and the second display area DA2. When the afterimage is displayed differently in the first display area DA1 and the second display area DA2, the afterimage can be more easily recognized by the user visually, and the boundary between the first display area DA1 and the second display area DA2 can be visually recognized by the user. Therefore, when the display time T of the third image IM3, which is the worst pattern, is longer than the predetermined reference time TT, the frequency mode determination unit 110 changes the operation mode to the normal mode so as to drive the first display area DA1 and the second display area DA2 at the normal frequency. As a result, the afterimage deviation between the first display area DA1 and the second display area DA2 can be minimized, and the boundary between the first display area DA1 and the second display area DA2 can be prevented from being visually recognized by the user.

[0191] Figure 17 This is a flowchart illustrating an embodiment of the operation of the drive controller according to the present invention in multi-frequency mode.

[0192] Reference Figure 8 , Figure 14 and Figure 17During multi-frequency mode, the first display area DA1 can be driven by a first driving frequency, and the second display area DA2 can be driven by a second driving frequency lower than the first driving frequency.

[0193] The frequency mode determination unit 110 of the drive controller 100 determines whether a still image is displayed in the first display area DA1 in the multi-frequency mode (operation S500). That is, the frequency mode determination unit 110 determines whether the image signal RGB corresponding to the first display area DA1 includes a still image.

[0194] like Figure 14 As shown, when the image signal RGB corresponding to the first display area DA1 includes both the first image IM1 as a moving image and the third image IM3 as a still image, the frequency pattern determination unit 110 determines whether the third image IM3 as a still image is the worst pattern (operation S510).

[0195] As described above, when the still image to be displayed in the first display area DA1 corresponds to any one of a predetermined pattern such as a matrix pattern, a stripe pattern, a dot pattern, and a zigzag pattern, which has areas with high brightness and areas with low brightness, the frequency mode determination unit 110 can determine that the still image to be displayed in the first display area DA1 is the worst pattern.

[0196] When the still image to be displayed in the first display area DA1 is not the worst pattern, the frequency mode determination unit 110 maintains the multi-frequency mode.

[0197] When the still image to be displayed in the first display area DA1 is the worst pattern, the frequency mode determination unit 110 compares the display area SA of the third image IM3 to be displayed in the first display area DA1 with the reference area SAT (operation S520).

[0198] In an embodiment, for example, when the ratio L2 of the length L2 of the third image IM3 in the first direction DR1 to the length L1+L2 of the first display area DA1 in the first direction DR, L2 / (L1+L2) is equal to or greater than a predetermined value (1 / 3), the frequency mode determination unit 110 can determine that the display area SA of the third image IM3 is greater than the reference area SAT.

[0199] In an embodiment, when the ratio of the length of the third image IM3 in the first direction DR1 to the length of the first display area DA1 in the first direction DR1 is equal to or greater than a predetermined value, the frequency mode determination unit 110 can determine that the display area SA of the third image IM3 is greater than the reference area SAT.

[0200] In an embodiment, when the length L2 of the third image IM3 in the first direction DR1 is greater than 1 / 2 of the length L1 of the first image IM1 in the first direction DR1, the frequency mode determination unit 110 can determine that the display area SA of the third image IM3 is greater than the reference area SAT.

[0201] When the display area SA of the third image IM3 to be displayed in the first display area DA1 is smaller than the reference area SAT, the frequency mode determination unit 110 maintains the multi-frequency mode.

[0202] When the display area SA of the third image IM3 to be displayed in the first display area DA1 is greater than the reference area SAT, the frequency mode determination unit 110 starts counting the display time T of the still images displayed in the first display area DA1 (operation S530). Although not shown in the figures, the frequency mode determination unit 110 may include a counter.

[0203] The frequency mode determination unit 110 determines whether the display time T is longer than a predetermined first reference time TT1 (or threshold time) (operation S540).

[0204] When the display time T is not longer than the first reference time TT1, the frequency mode determination unit 110 maintains the multi-frequency mode. During the multi-frequency mode, the display time T of the third image IM3, which is a still image, can continue to be counted.

[0205] When the display time T is longer than the first reference time TT1, the frequency mode determination unit 110 maintains the operation mode as multi-frequency mode, but changes the second driving frequency of the second display area DA2 to a first intermediate frequency F1, and outputs a mode signal MD corresponding to the first intermediate frequency F1 (operation S550). The first intermediate frequency F1 may be higher than the initial frequency of the second driving frequency. In an embodiment, for example, the initial frequency of the second driving frequency may be about 1 Hz, and the first intermediate frequency F1 may be about 10 Hz.

[0206] The frequency mode determination unit 110 determines whether the display time T is longer than a predetermined second reference time TT2 (or a threshold time) (operation S560). The second reference time TT2 may be greater than the first reference time TT1 (TT2>TT1).

[0207] When the display time T is not longer than the second reference time TT2, the frequency mode determination unit 110 maintains the multi-frequency mode. During the multi-frequency mode, the display time T of the third image IM3, which is a still image, can continue to be counted.

[0208] When the display time T is longer than the second reference time TT2, the frequency mode determination unit 110 maintains the operation mode as multi-frequency mode, but changes the second driving frequency of the second display area DA2 to a second intermediate frequency F2, and outputs a mode signal MD corresponding to the second intermediate frequency F2 (operation S570). The second intermediate frequency F2 may be higher than the first intermediate frequency F1 of the second driving frequency. In an embodiment, for example, the first intermediate frequency of the second driving frequency may be about 10 Hz, and the second intermediate frequency F2 may be about 30 Hz.

[0209] The frequency mode determination unit 110 determines whether the display time T is longer than the third reference time TT3 (or the threshold time) (operation S580). The third reference time TT3 may be greater than the second reference time TT2, and the second reference time TT2 may be greater than the first reference time TT1 (TT3>TT2>TT1).

[0210] When the display time T is not longer than the third reference time TT3, the frequency mode determination unit 110 maintains the multi-frequency mode. During the multi-frequency mode, the display time T of the third image IM3, which is a still image, can continue to be counted.

[0211] When the display time T is longer than the third reference time TT3, the frequency mode determination unit 110 changes the operation mode to normal mode so as to drive the first display area DA1 and the second display area DA2 at normal frequency (operation S590). As a result, the afterimage deviation between the first display area DA1 and the second display area DA2 can be minimized, and the boundary between the first display area DA1 and the second display area DA2 can be prevented from being visually recognized by the user.

[0212] Figure 18 It is shown in Figure 14 The image shown is a view of the residual images remaining on the display device after the first to third images have been displayed for an extended period of time in multi-frequency mode.

[0213] Reference Figure 14 and Figure 18 In multi-frequency mode, the first display area DA1 can be driven by the first driving frequency, and the second display area DA2 can be driven by the second driving frequency, which is lower than the first driving frequency.

[0214] According to its period Figure 14 The time that the first image IM1, the second image IM2, and the third image IM3 have been displayed in the first display area DA1 in multi-frequency mode can be used to determine the second driving frequency of the second display area DA2. In an embodiment, for example, as shown... Figure 16 As shown, when the display time T of a still image in multi-frequency mode is longer than a predetermined reference time TT, the operation mode changes to normal mode. In an embodiment, for example, as... Figure 17As shown, when the display time T of the still image in multi-frequency mode is longer than the first reference time TT1 and the second reference time TT2, the second driving frequency of the second display area DA2 is sequentially changed to the first intermediate frequency F1 and the second intermediate frequency F2. Additionally, when the display time T of the still image in multi-frequency mode is longer than the third reference time TT3, the operation mode changes to normal mode.

[0215] After the second image IM2 and the third image IM3 have been displayed for a long period of time in the first display area DA1 and the second display area DA2, such as Figure 18 As shown, a new image (e.g., an image corresponding to grayscale for gray color) can be displayed in the entire display area DA.

[0216] Although an image with the same grayscale (e.g., grayscale for gray color) is displayed throughout the entire display area DA, the image IM3 (refer to) is different. Figure 14 The afterimage IM3b caused by the second image IM2 (refer to) is displayed in the first display area DA1, and is also displayed in the second display area DA1. Figure 14 The resulting afterimage IM2b is displayed in the second display area DA2.

[0217] The frequency mode determination unit 110 in the embodiment can be as follows: Figure 16 and Figure 17 Operate as shown. In this case, as... Figure 18 As shown, the afterimage IM3b shown in the first display area DA1 and the afterimage IM2b shown in the second display area DA2 may have the same brightness.

[0218] When images of the same grayscale are displayed for a long period of time in the first display area DA1 and the second display area DA2, the afterimage IM3b shown in the first display area DA1 and the afterimage IM2b shown in the second display area DA2 have the same brightness, so that the brightness difference between the areas can be minimized.

[0219] When a moving image is displayed in the first display area and a still image is displayed in the second display area, the display device with the above configuration can be driven in a multi-frequency mode where the first display area is driven at a first driving frequency and the second display area is driven at a second driving frequency. When a still image and a moving image are simultaneously displayed in the first display area in multi-frequency mode, the operation mode can be changed to a normal mode according to the characteristics of the still image and the display time. Therefore, the afterimage deviation caused by the difference in driving frequency when a still image is displayed in a part of the first display area and the second display area for a long period of time can be minimized.

[0220] Although the invention has been described with reference to embodiments thereof, those skilled in the art will understand that various modifications and changes in form and detail may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims. Furthermore, the embodiments disclosed herein are not intended to limit the technical spirit of the invention, and all technical concepts falling within the scope of the appended claims and their equivalents are to be interpreted as being included within the scope of the invention.

Claims

1. A display device, comprising: The display panel includes multiple pixels, which are respectively connected to a corresponding data line among multiple data lines and a corresponding scan line among multiple scan lines; Data driving circuit, driving the plurality of data lines; The scan driving circuit drives the plurality of scan lines; as well as A drive controller controls the data drive circuit and the scan drive circuit such that during multi-frequency mode, the display panel is divided into a first display area and a second display area, and the first display area and the second display area are operated at different frequencies. Specifically, when a still image and a moving image are simultaneously displayed in the first display area during the multi-frequency mode, and the duration of the still image reaches a predetermined time, the drive controller changes the operation mode to normal mode. During the normal mode, each of the first and second display areas is driven at a normal frequency.

2. The display device according to claim 1, wherein, During the multi-frequency mode, the first display area is driven at a first driving frequency, and the second display area is driven at a second driving frequency lower than the first driving frequency.

3. The display device according to claim 2, wherein, The first driving frequency is the same as the normal frequency.

4. The display device according to claim 1, wherein, The drive controller includes: The frequency mode determination unit determines the operating mode based on the image signal and the control signal and outputs a mode signal; and The signal generator outputs data control signals and scan control signals corresponding to the pattern signal. The data control signal is provided to the data driving circuit, and the scan control signal is provided to the scan driving circuit.

5. The display device according to claim 4, wherein, When the still image and the moving image are simultaneously displayed in the first display area during the multi-frequency mode and the duration of the still image reaches the predetermined time, the frequency mode determination unit changes the operation mode so that the mode signal represents the normal mode.

6. The display device according to claim 4, wherein, When the average brightness of the still image displayed in the first display area is higher than the reference brightness, the frequency mode determination unit changes the operating mode so that the mode signal represents the normal mode.

7. The display device according to claim 4, wherein, When the average brightness of the still image displayed in the first display area is higher than the reference brightness and the duration of the still image reaches the predetermined time, the frequency mode determination unit changes the operation mode so that the mode signal represents the normal mode.

8. The display device according to claim 4, wherein, When the still image displayed in the first display area is the worst pattern and the duration of the still image reaches the predetermined time, the frequency mode determination unit changes the operating mode so that the mode signal represents the normal mode; The worst pattern is a pattern in which high-brightness areas and low-brightness areas are alternately arranged in a first direction or a second direction, or an image that does not have a predetermined shape but in which high-brightness areas and low-brightness areas appear randomly.

9. The display device according to claim 4, wherein, When the still image displayed in the first display area is the worst pattern and the display area of ​​the still image is larger than the reference area, the frequency mode determination unit changes the mode signal according to the duration of the still image to indicate the normal mode. The worst pattern is a pattern in which high-brightness areas and low-brightness areas are alternately arranged in a first direction or a second direction, or an image that does not have a predetermined shape but in which high-brightness areas and low-brightness areas appear randomly.

10. The display device according to claim 9, wherein, The frequency mode determination unit further: When the duration of the still image reaches a first reference time, the frequency of the second display area is changed to a first intermediate frequency; and When the duration of the still image reaches a second reference time, the frequency of the second display area is changed to a second intermediate frequency, wherein the second reference time is greater than the first reference time, and the second intermediate frequency is higher than the first intermediate frequency.

11. The display device according to claim 10, wherein, The frequency mode determination unit further changes the mode signal to indicate the normal mode when the duration of the still image reaches a third reference time, wherein the third reference time is greater than the second reference time.

12. The display device according to claim 9, wherein, The frequency mode determination unit further determines that the display area of ​​the still image is greater than the reference area when the ratio of the length of the still image in the first direction to the length of the first display area in the first direction is equal to or greater than a predetermined value.

13. A method for driving a display device, the method comprising: During multi-frequency mode, the display panel is divided into a first display area and a second display area; The first display area is driven at a first driving frequency, and the second display area is driven at a second driving frequency; Determine that still images and moving images are displayed simultaneously in the first display area; as well as When the duration of the still image reaches a predetermined time, the operation mode will be changed to normal mode. During the normal mode, each of the first and second display areas is driven at a normal frequency.

Images