Display device and electronic device

Abstract

The invention relates to a display device and an electronic device. The display device includes a display panel, in which the display panel includes pixels and displays an image. The driver converts input image data into image data, generates a data signal based on the image data, and provides the data signal to the pixels according to a refresh rate. When a refresh rate is changed from a first refresh rate to a second refresh rate to display an image having a first brightness, the driver adjusts a brightness of a first frame displaying the image at the second refresh rate to a second brightness different from the first brightness.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to and all benefits derived therefrom of Korean Patent Application No. 10-2024-0075697, filed on June 11, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to display devices, and more particularly, to display devices and electronic devices including display devices. Background Technology

[0004] The display device includes a plurality of pixels, wherein each of the plurality of pixels includes a plurality of transistors, a light-emitting element electrically connected to the plurality of transistors, and a capacitor. The plurality of transistors are turned on in response to a signal provided via wiring, thereby generating a predetermined drive current, wherein the light-emitting element emits light in response to the drive current. Summary of the Invention

[0005] The embodiments provide a display device capable of improving visibility and an electronic device including the display device.

[0006] In one embodiment, a display device may include: a display panel including pixels and displaying an image; and a driver that converts input image data into image data, the driver generating a data signal based on the image data, and the driver providing the data signal to the pixels according to a refresh rate. When the refresh rate changes from a first refresh rate to a second refresh rate to display an image with a first brightness, the driver may adjust the brightness of a first frame of the image displayed at the second refresh rate to a second brightness different from the first brightness.

[0007] In one embodiment, when the second refresh rate is less than the first refresh rate, the driver can reduce the second brightness to a level lower than the first brightness.

[0008] In an embodiment, in response to the change in refresh rate, the driver can change the on-duty period based on the time of the image, the on-duty period representing the ratio of the time the pixel emits light during a frame, and the driver can change the peak brightness based on the time of the image.

[0009] In one embodiment, the driver can adjust the peak brightness to be between a first peak brightness according to the first refresh rate and a second peak brightness according to the second refresh rate, based on the time of the image in the first frame.

[0010] In an embodiment, the peak brightness of the first frame may be in the range of about 85% to about 97% of the second peak brightness.

[0011] In an embodiment, the peak brightness of the first frame may be within the range of approximately ±10% of the average of the first peak brightness and the second peak brightness.

[0012] In an embodiment, the driver may select one of a plurality of gamma voltages based on the grayscale value of the image data for the pixel, and output the selected one of the plurality of gamma voltages as the data signal, and set the plurality of gamma voltages in the first frame to be different from the plurality of gamma voltages for the second peak brightness.

[0013] In one embodiment, the driver can convert the input image data into image data based on the refresh rate and apply weights to generate image data for the first frame.

[0014] In one embodiment, the driver can drive the display panel to display the image with the first brightness in a second frame following the first frame.

[0015] In an embodiment, when the difference between the first refresh rate and the second refresh rate is greater than a reference value, the driver can adjust the brightness of the second frame after the first frame to be between the first brightness and the second brightness.

[0016] In one embodiment, when the second refresh rate is less than the first refresh rate, the driver can increase the second brightness to a level higher than the first brightness.

[0017] In an embodiment, when the difference or ratio between the first refresh rate and the second refresh rate exceeds a reference range, the driver can adjust the brightness of the first frame to be equal to the second brightness, and when the difference or ratio is within the reference range, the driver can maintain the brightness of the first frame at the first brightness.

[0018] In one embodiment, an electronic device may include: a processor that provides input image data; and a display device that displays an image having a first brightness corresponding to the input image data. When the processor changes the refresh rate of the image from the first refresh rate to a second refresh rate, the display device may display the image at a second brightness different from the first brightness during at least one frame, and display the image at the first brightness after the at least one frame.

[0019] In one embodiment, when the second refresh rate is less than the first refresh rate, the display device may reduce the second brightness to a level lower than the first brightness.

[0020] In an embodiment, the display device can change the peak brightness according to the time of the image based on the refresh rate, and adjust the peak brightness in the at least one frame to be between a first peak brightness according to the first refresh rate and a second peak brightness according to the second refresh rate.

[0021] In one embodiment, a display device may include: a display panel including pixels and displaying an image; and a driver that converts input image data into image data, generates a data signal based on the image data, and provides the data signal to the pixels according to a refresh rate. When the refresh rate changes from a first refresh rate to a second refresh rate to display an image with a first brightness, in a third interval between a first interval where the image is displayed at the first refresh rate and a second interval where the image is displayed at the second refresh rate, the driver may adjust the brightness of the image to a second brightness different from the first brightness.

[0022] In one embodiment, the driver can adjust the refresh rate of the image to a third refresh rate that is different from the first refresh rate and the second refresh rate in the third interval.

[0023] In an embodiment, the third refresh rate may be a value between the first refresh rate and the second refresh rate.

[0024] In one embodiment, the driver can change the peak brightness according to the time of the image based on the refresh rate, and adjust the peak brightness in the third interval to be between a first peak brightness based on the first refresh rate and a second peak brightness based on the second refresh rate.

[0025] In an embodiment, the third interval may include two or fewer frames.

[0026] Other specific details of the embodiments are included in the detailed description and drawings. Attached Figure Description

[0027] 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 exemplary embodiments of the invention and, together with the description, serve to illustrate the principles of the invention.

[0028] Figure 1 This is a schematic block diagram illustrating a display device according to an embodiment.

[0029] Figure 2AThis is a conceptual diagram used to explain an example of a method for driving a display device according to an image refresh rate according to an embodiment.

[0030] Figure 2B This is a conceptual diagram used to explain an example of a method for driving a display device according to an image refresh rate according to an embodiment.

[0031] Figure 2C This is a conceptual diagram used to explain an example of a method for driving a display device according to an image refresh rate according to an embodiment.

[0032] Figure 3A This is a graph used to explain a comparative example of actual brightness changes according to the image refresh rate in accordance with an embodiment.

[0033] Figure 3B This is a graph used to explain a comparative example of perceived brightness according to changes in image refresh rate, based on an embodiment.

[0034] Figure 4 It is shown that, according to the embodiments, it includes Figure 1 The operation block diagram of the image controller in the display device.

[0035] Figure 5 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment.

[0036] Figure 6 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment.

[0037] Figure 7 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment.

[0038] Figure 8 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment.

[0039] Figure 9 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment.

[0040] Figure 10 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment.

[0041] Figure 11 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment.

[0042] Figure 12 This is a block diagram illustrating an electronic device according to an embodiment. Detailed Implementation

[0043] Because this invention allows for various modifications and numerous embodiments, specific embodiments will be shown in the accompanying drawings and described in detail in the written description. However, this is not intended to limit the invention to particular modes of practice. 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, “first element” discussed below may be referred to as “second element” without departing from the scope of this disclosure. Similarly, “second element” may also be referred to as “first element.” In this disclosure, singular expressions are intended to include plural expressions as well, unless the context clearly indicates otherwise. Some embodiments relating to functional blocks, units, and / or modules are depicted in the accompanying drawings. Those skilled in the art will understand that these blocks, units, and / or modules are physically implemented by logic circuits, individual components, microprocessors, hardwired circuits, memory elements, wire connections, and other electronic circuits. This can be formed using semiconductor-based manufacturing techniques or other manufacturing techniques. Blocks, units, and / or modules implemented by microprocessors or other similar hardware can be software-programmed and controlled to perform the various functions discussed herein, and may optionally be driven by firmware and / or software. Furthermore, each block, unit, and / or module can be implemented by dedicated hardware or a combination of dedicated hardware performing some functions and processors performing functions different from those of the dedicated hardware (e.g., one or more programmed microprocessors and associated circuitry). Additionally, in some embodiments, blocks, units, and / or modules can be physically separated into two or more interacting individual blocks, units, and / or modules without departing from the scope of the invention. Furthermore, in some embodiments, blocks, units, and / or modules can be physically combined into more complex blocks, units, and / or modules without departing from the scope of the invention.

[0044] In the following description, a display device according to an embodiment will be described with reference to the accompanying drawings relating to embodiments of the present invention.

[0045] Figure 1 This is a schematic block diagram illustrating a display device according to an embodiment. Figure 2A , Figure 2B and Figure 2C This is a conceptual diagram used to explain an example of a method for driving a display device according to an image refresh rate according to an embodiment. Figure 3A This is a graph used to explain a comparative example of actual brightness changes according to the image refresh rate in accordance with an embodiment. Figure 3B This is a graph used to explain a comparative example of perceived brightness according to changes in image refresh rate, based on an embodiment.

[0046] refer to Figure 1 According to an embodiment, the display device 100 may include a display panel 110 and a driver 120.

[0047] The display panel 110 (or display unit) may include pixels PXij, where i and j can be integers greater than 0. Each pixel PXij may be connected to a corresponding data line and a corresponding scan line. Here, pixel PXij may refer to a pixel in which the scan transistor is connected to the i-th scan line and the j-th data line. Pixel PXij may store or write a data signal provided via the j-th data line in response to a scan signal provided via the i-th scan line, and emit light with a brightness corresponding to the stored data signal in response to an emission control signal provided via the j-th emission control line. Pixel PXij may include a light-emitting element composed of organic and / or inorganic materials.

[0048] In an embodiment, the driver 120 can convert input image data IDATA into image data DATA, generate a data signal based on the image data DATA, and provide the data signal to the display panel 110 or pixel PXij according to the image refresh rate (or refresh rate, hereinafter referred to as "refresh rate").

[0049] The driver 120 may include a scan driver 121, a data driver 122, a transmit driver (or EM driver) 123, a timing controller 124, and an image controller 125.

[0050] In this embodiment, the timing controller 124 may receive input image data IDATA and control signal CS from an external device (e.g., a processor). Here, the control signal CS may include a synchronization signal and a clock signal, etc.

[0051] In this embodiment, the timing controller 124 can generate a first control signal SCS (or scan drive control signal), a second control signal DCS (or data drive control signal), and a third control signal ECS (or transmit drive control signal) based on the control signal CS. The timing controller 124 can provide the first control signal SCS to the scan driver 121, the second control signal DCS to the data driver 122, and the third control signal ECS to the transmit driver 123.

[0052] The first control signal SCS may include a scan start signal and a scan clock signal, etc. The scan start signal can be a signal used to control the timing of the scan signals, and the scan clock signal can be used to shift the scan start signal.

[0053] The second control signal DCS may include a source start signal and a data clock signal. The source start signal controls the starting point of data sampling, and the data clock signal can be used to control the sampling operation.

[0054] The third control signal (ECS) may include a transmit start signal and a transmit clock signal. The transmit start signal can be a signal used to control the timing of the transmit control signals, and the transmit clock signal can be used to shift the transmit start signal.

[0055] In this embodiment, the input image data IDATA may include grayscale values ​​of an input image corresponding to at least one frame. For example, the input image data IDATA may include the grayscale values ​​of each of a plurality of consecutive input images, frame by frame.

[0056] In one embodiment, the timing controller 124 can generate image data DATA based on the input image data IDATA and provide the image data DATA to the data driver 122.

[0057] In an embodiment, scan driver 121 may provide scan signals to scan lines SL1 to SLn based on a first control signal SCS, where n may be an integer greater than 0. For example, scan driver 121 may sequentially provide scan signals with on-level pulses to scan lines SL1 to SLn.

[0058] When a scan signal with a conduction level is sequentially provided, pixels PXij can be selected on a horizontal line basis (or on a pixel row basis), and data signals can be provided to the selected pixels PXij. For this purpose, the scan signal with the conduction level can be set to a gate conduction voltage (low voltage or high voltage) so that the transistor included in each pixel PXij and receiving the scan signal can be turned on.

[0059] In one embodiment, the data driver 122 may, in response to a second control signal DCS, provide a data signal (or data voltage) corresponding to the image data DATA to data lines DL1 to DLm, where m may be an integer greater than 0. The data signal provided to data lines DL1 to DLm may be provided to the pixel PXij selected by the scan signal. For this purpose, the data driver 122 may provide the data signal to data lines DL1 to DLm synchronously with a scan signal at an on-level.

[0060] In this embodiment, the transmit driver 123 can provide transmit control signals to transmit control lines EM1 to EMn based on a third control signal ECS. For example, the transmit driver 123 can sequentially provide transmit control signals with on-level pulses to transmit control lines EM1 to EMn. When an on-level transmit control signal is provided, pixel PXij can emit light with a brightness corresponding to the data signal. The emission time of pixel PXij can be determined by the width (i.e., pulse width) of the on-level transmit control signal.

[0061] In this embodiment, the display device 100 can display images at various refresh rates (drive frequency or screen refresh rate) depending on the driving conditions. The refresh rate can refer to the frequency at which valid data signals are written to pixel PXij (e.g., the drive transistor included in pixel PXij). For example, the refresh rate can also be referred to as the screen refresh rate or screen refresh frequency, and can indicate the frequency at which the display screen is refreshed per second.

[0062] In an embodiment, in response to the refresh rate, the output frequency of the data driver 122, the output frequency of the scan driver 121, and / or the output frequency of the transmit driver 123 for a horizontal line (or row of pixels) can be determined. For example, the refresh rate for driving dynamic images may be a frequency of about 120 Hz or higher (e.g., 120 Hz, 240 Hz, 360 Hz, or 480 Hz, etc.), and the refresh rate for driving static images may be a frequency of about 60 Hz or lower (e.g., 30 Hz or 60 Hz, etc.). However, this is merely an example, and the invention is not limited thereto.

[0063] In this embodiment, to improve image quality, a frame period may include multiple non-emission periods and multiple emission periods depending on the refresh rate. For example, the first non-emission period and the first emission period of a frame may be defined as a first drive period, and subsequent non-emission periods and emission periods may be defined as a second drive period. During the first drive period, a valid image corresponding to the image data DATA may be displayed on the display panel 110. During the second drive period, a black image (e.g., an image to prevent afterimages) may be displayed on the display panel 110, or a valid image may not be displayed on the display panel 110, but the invention is not limited thereto.

[0064] For a more detailed description of refresh rates, please refer to further information. Figures 2A to 2C The display device 100 can be driven at various refresh rates.

[0065] In this embodiment, the frequency of the first driving cycle DP1 can correspond to the refresh rate.

[0066] In an embodiment, such as Figure 2A As shown, a frame FRa may include a first drive cycle DP1. For example, when the frequency of the first drive cycle DP1 is approximately 240Hz, the corresponding frame FRa can be driven at approximately 240Hz. That is, the corresponding frame FRa can be driven at a refresh rate of approximately 240Hz. For example, the length of the first drive cycle DP1 and the corresponding frame FRa can be approximately 4.17ms.

[0067] In an embodiment, such as Figure 2BAs shown, a frame FRb can include a first drive cycle DP1 and a second drive cycle DP2. For example, the first drive cycle DP1 and the second drive cycle DP2 can repeat. For example, the first drive cycle DP1 and the second drive cycle DP2 can have the same length. In this case, the corresponding frame FRb can be driven at approximately 120Hz. That is, the corresponding frame FRb can be driven at an image refresh rate of approximately 120Hz. For example, the length of a first drive cycle DP1 and a second drive cycle DP2 can be approximately 4.17ms, and the length of the corresponding frame FRb can be approximately 8.33ms.

[0068] In an embodiment, such as Figure 2C As shown, a frame FRc may include a first drive cycle DP1 and multiple repeated second drive cycles DP2. For example, when the corresponding frame FRc is driven at approximately 1 Hz, the length of the corresponding frame FRc may be approximately 1 second, and the second drive cycle DP2 may be repeated approximately 239 times within the corresponding frame FRc. That is, the corresponding frame FRc may be driven at an image refresh rate of approximately 1 Hz.

[0069] In this way, by controlling the number of repetitions of the second drive cycle DP2 within a frame, the display device 100 can be freely driven at various refresh rates (e.g., 1Hz to 480Hz).

[0070] More specifically, at various refresh rates, the lengths of a first drive cycle DP1 and a second drive cycle DP2 can be fixed (e.g., the lengths of a first drive cycle DP1 and a second drive cycle DP2 can be fixed at approximately 4.17 ms corresponding to approximately 240 Hz), and the display device 100 can be driven at various refresh rates by controlling the number of repetitions of the second drive cycle DP2 within a frame. For example, as the number of second drive cycles DP2 within a frame increases, the refresh rate of the display device 100 can decrease. As an example, when the number of second drive cycles DP2 included in a frame is p, the display device 100 can be driven at a refresh rate of 240 / (p+1) Hz, where p can be an integer greater than or equal to 0. That is, the refresh rate of the display device 100 can be set as a divisor of the frequency (e.g., 240 Hz) corresponding to the length of the first drive cycle DP1, based on the number of second drive cycles DP2 included in a frame.

[0071] However, this is just an example, and the length of a first drive cycle DP1 and the length of a second drive cycle DP2 can be fixed at about 2.08ms corresponding to about 480Hz, and the refresh rate of the display device 100 can be set as a divisor of about 480Hz based on the number of second drive cycles DP2 included in a frame.

[0072] Furthermore, when the refresh rate of the display device 100 changes (or switches) (e.g., when the refresh rate switches from 120Hz to 60Hz or from 240Hz to 60Hz), transient flashing may occur. For example, when the refresh rate of the display device 100 is switched, the user may perceive a temporary increase in the brightness of the displayed image, and the user may perceive a flickering effect in the displayed image (e.g., a flickering phenomenon that can be perceived by the user).

[0073] For example, further reference Figure 3A and Figure 3B , Figure 3A A graph showing a comparison example of actual brightness when the display device is driven from a first refresh rate RR1 to a second refresh rate RR2 is shown. Figure 3B A graph showing a comparison example of perceived brightness as perceived by the user when the display device is driven from a first refresh rate RR1 to a second refresh rate RR2 is shown.

[0074] In the embodiments and reference Figure 3A According to the comparative example, the display device can be driven at a first refresh rate RR1 in a first cycle P1 (or a first interval), and at a second refresh rate RR2 in a second cycle P2 (or a second interval) following the first cycle P1. Here, the first refresh rate RR1 and the second refresh rate RR2 can be different from each other. For example, the first refresh rate RR1 can be greater than the second refresh rate RR2. For example, the first refresh rate RR1 can be approximately 120Hz, and the second refresh rate RR2 can be approximately 60Hz. However, the invention is not limited thereto, and the second refresh rate RR2 can be greater than the first refresh rate RR1. In the following description, for ease of description, the description will be based on the case where the first refresh rate RR1 is greater than the second refresh rate RR2.

[0075] In an embodiment, since the first refresh rate RR1 is greater than the second refresh rate RR2, the length of each frame FR_P1 in the first period P1 driven by the display device at the first refresh rate RR1 (as shown in "t1") can be shorter than the length of each frame FR_P2 in the second period P2 driven by the display device at the second refresh rate RR2 (as shown in "t2") (e.g., the cycle period for writing data signals to the display device can be shorter). For example, when the display device is driven at the first refresh rate RR1 (e.g., about 120 Hz), the data signal can be written with a cycle period of about 8.33 ms, and when the display device is driven at the second refresh rate RR2 (e.g., 60 Hz), the data signal can be written with a cycle period of about 16.67 ms.

[0076] like Figure 3AAs shown, the display device according to the comparative example can be driven by a refresh rate that switches from a first refresh rate RR1 to a second refresh rate RR2.

[0077] For ease of description, the description will be based on an embodiment in which the brightness of an image displayed by the display device according to the comparative example in a first period P1 is the same as the brightness of an image displayed by the display device according to the comparative example in a second period P2. For example, the image displayed by the display device according to the comparative example may have the same first average brightness Lav_A in both the first period P1 and the second period P2.

[0078] In the embodiments and further reference Figure 3B When the display device according to the comparative example is driven at a first refresh rate RR1 in the first cycle P1 and then switches the refresh rate and is driven at a second refresh rate RR2 in the second cycle P2, the average perceived brightness by the user can have the same value in the first cycle P1 and the second cycle P2. For example, as referenced Figure 3A The description states that since the actual brightness of the image displayed by the display device has the same average value (e.g., first average brightness Lav_A) in the first period P1 and the second period P2, the brightness perceived by the user can also have the same average value (e.g., second average brightness Lav_P) in the first period P1 and the second period P2.

[0079] However, when switching the refresh rate of the display device, transient flickering may occur, in which users can perceive a temporary increase in the brightness of the displayed image.

[0080] In the embodiments and as Figure 3B As shown, even if the average perceived brightness perceived by the user in the first cycle P1 and the second cycle P2 is the same as the second average brightness Lav_P, the perceived brightness may temporarily increase due to the transient flash phenomenon described above in response to the time point when the refresh rate switches from the first cycle P1 to the second cycle P2 (e.g., immediately after the first cycle P1). For example, in response to the time point when the refresh rate switches from the first cycle P1 to the second cycle P2 (e.g., in the transition cycle Pcov immediately after the first cycle P1), the perceived brightness may temporarily increase to the peak brightness Lpk (or flash brightness). If the peak brightness Lpk is greater than or equal to the threshold TV, the user may perceive transient flash (or flicker) at the moment of refresh rate switching, even if the average brightness of the corresponding displayed image is the same when switching refresh rates. Here, the threshold TV may refer to a reference value for the flash brightness of the transient flash phenomenon (e.g., flicker perceived by the user) when switching refresh rates.

[0081] In an embodiment, the value of the peak luminance Lpk (or flash luminance) at the transition time point from the first period P1 to the second period P2 (e.g., the transition time point tcov) is compared with the value of the perceived luminance (in Figure 3B The greater the difference between the peak luminance Lpk (or flash luminance) and the perceived luminance Lcov, the stronger the transient flash phenomenon described above may be. For example, the greater the difference between the peak luminance Lpk (or flash luminance) and the perceived luminance Lcov at the transition point from the first cycle P1 to the second cycle P2, the more severe the flash (or flicker) phenomenon in the displayed image may be as perceived by the user.

[0082] In the embodiments and as Figure 3A As shown, during each frame FR_P1 in the first period P1, the actual brightness can decrease from a first maximum brightness L_Amax1 to a first minimum brightness L_Amin1. For example, when in Figure 2B When a valid image is displayed in the first driving cycle DP1, the actual brightness can increase to a first maximum brightness L_Amax1, and when a black image or no valid image is displayed in the second driving cycle DP2, the actual brightness can decrease to a first minimum brightness L_Amin1. That is, in response to driving the refresh rate of the display device in the first cycle P1, the value of the actual brightness can periodically change between the maximum brightness L_Amax1 and the minimum brightness L_Amin1. Here, since the display device is typically driven at a refresh rate higher than the user's critical fusion frequency (CFF), the user will not perceive a significant difference in brightness. Figure 3A The actual brightness shown changes periodically, but rather... Figure 3B As shown, the user can perceive that the brightness of the displayed image is constant during the first period P1. For example, the user can perceive that the brightness of the displayed image has a constant value such as a second average brightness Lav_P during the first period P1, which is an intermediate value between the maximum brightness L_Amax1 and the minimum brightness L_Amin1.

[0083] Similarly, such as Figure 3A As shown, during each frame FR_P2 in the second period P2, the actual brightness can decrease from the second maximum brightness L_Amax2 to the second minimum brightness L_Amin2. For example, as the refresh rate decreases, Figure 2BThe number or width of the second driving cycle DP2 can be increased, and the maximum brightness in the second cycle P2 (i.e., the second maximum brightness L_Amax2) can be greater than the maximum brightness in the first cycle P1 (i.e., the first maximum brightness L_Amax1), such that each frame FR_P1 in the second cycle P2 has the same brightness (e.g., the first average brightness Lav_A) as each frame FR_P1 in the first cycle P1. The minimum brightness in the second cycle P2 (i.e., the second minimum brightness L_Amin2) can be lower than the minimum brightness in the first cycle P1 (i.e., the first minimum brightness L_Amin1), but the invention is not limited thereto. For example, the second minimum brightness L_Amin2 can be equal to the first minimum brightness L_Amin1. That is, in response to the refresh rate driven by the display device in the second cycle P2, the actual brightness value can change periodically between the second maximum brightness L_Amax2 and the second minimum brightness L_Amin2. The user will not perceive the brightness as... Figure 3A The actual brightness shown changes periodically, but rather... Figure 3B As shown, the user can perceive that the brightness of the displayed image is constant during the second cycle P2. For example, as mentioned above, since the second refresh rate RR2 has a smaller value than the first refresh rate RR1, the second refresh rate RR2 can have a value closer to the user's critical fusion frequency. Therefore, the perceived brightness by the user during the second cycle P2 can be slightly increased or slightly decreased based on the second average brightness Lav_P, but the actual brightness of the displayed image perceived by the user during the second cycle P2 is a generally constant value with the second average brightness Lav_P, which is an intermediate value between the second maximum brightness L_Amax2 and the second minimum brightness L_Amin2.

[0084] Furthermore, according to the Talbot-Plateau law, the perceived brightness of the displayed image as perceived by the user can be determined based on the corresponding image refresh rate.

[0085] In an embodiment, when the refresh rate of the display device switches from a first refresh rate RR1 to a second refresh rate RR2, due to the temporary change in refresh rate, according to the Talbot-Platau law described above, at the transition point from the first cycle P1 to the second cycle P2, the average value of the actual brightness during the period corresponding to the first refresh rate RR1 of the first cycle P1 can be perceived by the user as the brightness of the displayed image.

[0086] For example, such as Figure 3A As shown, the user can perceive that the displayed image is shown at the average actual brightness during the transition period Pcov, which has the same length t1 as the first frame FR1 immediately following the first period P1. Therefore, as Figure 3B As shown, the perceived brightness by the user during the transition period Pcov can temporarily increase to the peak brightness Lpk. Therefore, the user can perceive transient flashes (or flashes in the displayed image), and in this case, visibility may be reduced.

[0087] To prevent this phenomenon, the display device 100 according to the embodiment can control the brightness (and refresh rate) of the displayed image when switching refresh rates and displaying images.

[0088] In an embodiment, when the difference or ratio between the first refresh rate RR1 and the second refresh rate RR2 exceeds a reference range, the image controller 125 may increase or decrease the brightness of the first frame (or at least one frame including the first frame) of the second period P2. When the difference or ratio between the first refresh rate RR1 and the second refresh rate RR2 is within the reference range, the image controller 125 may adjust the brightness of the second period P2 without additional adjustment.

[0089] In an embodiment, the image controller 125 can detect light characteristic information of the image to be displayed on the display panel 110 (or light emitted by the display panel 110) from the input image data IDATA (or image data DATA). Here, the light characteristic information may include information about the light characteristics of the image to be displayed on the display panel 110. Figure 3A and Figure 3B The flash brightness described is the perceived brightness as perceived by the user (or Figure 3B The value of peak brightness (Lpk) is shown in the figure.

[0090] For example, in one embodiment, the image controller 125 can detect light characteristic information by predicting the value of the flash brightness that may occur when the refresh rate is switched.

[0091] In one embodiment, the image controller 125 can compare a value of the flash brightness predicted based on light characteristic information during refresh rate switching with a threshold TV. The threshold TV can be generated based on input image data IDATA and a control signal CS, which will be referenced... Figure 4 Detailed description.

[0092] In one embodiment, the image controller 125 may generate a brightness control signal LCS to control the brightness of the displayed image in response to a comparison between light characteristic information (e.g., the value of flash brightness) and a threshold TV.

[0093] For example, in one embodiment, when the flash brightness value is greater than or equal to a threshold TV, the image controller 125 can generate a brightness control signal LCS to gradually change the brightness.

[0094] In the embodiments and reference Figure 3AWhen the display device 100 changes its refresh rate from a first refresh rate RR1 to a second refresh rate RR2 to display an image with a first brightness (or a first average brightness Lav_A), the image controller 125 can generate a brightness control signal LCS to adjust the brightness of the image to a second brightness different from the first brightness in the first frame (including at least one frame of the first frame) of the second period P2 driven by the second refresh rate RR2. When the second refresh rate RR2 is less than the first refresh rate RR1, the second brightness can be lower than the first brightness. The maximum brightness of the second brightness can be between the first maximum brightness L_Amax1 of the first period P1 and the second maximum brightness L_Amax2 of the second period P2 (i.e., the remaining periods of the second period P2 excluding the at least one frame).

[0095] As another example, in an embodiment, during a third period (or third interval) between the first period P1 and the second period P2, the image controller 125 may generate a brightness control signal LCS to adjust the brightness of the image to a second brightness, and to display the image at a third refresh rate during the third period. Here, the third refresh rate may have a value between the first refresh rate and the second refresh rate.

[0096] In an embodiment, when the flash brightness value is less than the threshold TV, since the user will not perceive the transient flash even if the refresh rate of the display device 100 is switched, the image controller 125 can generate a brightness control signal LCS, causing the refresh rate of the display device 100 to immediately switch from the first refresh rate RR1 to the second refresh rate RR2. For example, the display device 100 can be driven at the first refresh rate RR1 in the first cycle P1, and then switched to the second refresh rate RR2 in the second cycle P2 immediately following the first cycle P1. However, the invention is not limited to this, and when the flash brightness value is greater than or equal to the threshold, the image controller 125 may not generate a separate control signal (e.g., the brightness control signal LCS).

[0097] In one embodiment, the image controller 125 may provide the brightness control signal LCS to the timing controller 124.

[0098] In an embodiment, the timing controller 124 can control the brightness of the displayed image based on the brightness control signal LCS. For example, the timing controller 124 can convert the input image data IDATA into image data based on the refresh rate, and can adjust the data of the first frame (or the data of the third cycle) of the second period P2 by applying weights according to the brightness control signal LCS. For example, the timing controller 124 can generate image data with a maximum data value or maximum gray level value of A (or X / 120) (not shown) based on a refresh rate of approximately 120Hz in the first cycle P1, generate image data with a maximum data value of B (or X / 80) (not shown) based on a refresh rate of approximately 80Hz in the second cycle P2, and generate image data with a maximum data value of C (or X / 100) (not shown) between A and B in the first frame or the third cycle of the second cycle P2.

[0099] Furthermore, based on the luminance control signal LCS, the timing controller 124 can control the output frequency of the data driver 122, the output frequency of the scan driver 121, and / or the output frequency of the transmit driver 123 for a horizontal line (or pixel row). As an example, the timing controller 124 can use a first control signal SCS (or scan drive control signal) to control the output frequency of the scan driver 121, and / or can use a second control signal DCS (or data drive control signal) to control the output frequency of the data driver 122.

[0100] In another embodiment, during the first frame or third cycle of the second period P2, the timing controller 124 may control the data driver 122 to adjust the data signal rather than the image data DATA. For example, the data driver 122 may generate a gamma voltage, select one of a plurality of gamma voltages to output the data signal based on the data value or grayscale value of the image data DATA, and adjust the gamma voltage based on the luminance control signal LCS. The luminance control signal LCS may be included in the second control signal DCS and provided from the timing controller 124 to the data driver 122, but the invention is not limited thereto. For example, the luminance control signal LCS may be provided from the image controller 125 to the data driver 122. For example, the data driver 122 can generate a gamma voltage (or data signal) with a maximum gamma voltage of D (or Y / 120) (not shown) based on a refresh rate of about 120 Hz in a first cycle P1, generate a gamma voltage with a maximum gamma voltage of E (or Y / 80) (not shown) based on a refresh rate of about 80 Hz in a second cycle P2, and generate a gamma voltage with a maximum gamma voltage of F (or Y / 100) (not shown) between D and E in the first frame or third cycle of the second cycle P2.

[0101] As described above, the display device 100 (or image controller 125) according to the embodiment can control the brightness (and refresh rate) of the image based on the value of the flash brightness according to the light characteristic information of the image to be displayed on the display panel 110. Therefore, even if the refresh rate of the display device 100 (or the displayed image) is switched, transient flickering phenomena perceived by the user can be prevented (e.g., eliminated) and visibility can be improved.

[0102] In one embodiment, the image controller 125 may be constituted as an integrated circuit chip (IC) separate from the timing controller 124. However, the invention is not limited thereto. For example, all or part of the image controller 125 may be constituted as an IC integrated with the timing controller 124. As another embodiment, all or part of the image controller 125 may be implemented in software within the timing controller 124.

[0103] Figure 4 It is shown that, according to the embodiments, it includes Figure 1 The diagram shows the operation block of the image controller in the display device. For ease of description, Figure 4 The timing controller 124 is further shown in the figure. According to an embodiment, Figure 5 , Figure 6 and Figure 7 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment. Figure 5 The average brightness for each frame is shown, and Figure 6 and Figure 7 The actual brightness (or the brightness data LDATA corresponding to the actual brightness) is shown.

[0104] In the embodiments and reference Figure 1 and Figure 4 The image controller 125 may include a refresh rate calculator 410, a grayscale calculator 420, a brightness calculator 430, and a brightness control signal generator 440.

[0105] The refresh rate calculator 410 can generate (or detect) refresh rate information FI corresponding to the refresh rate based on the control signal CS (and the input image data IDATA). For example, the refresh rate calculator 410 can generate the refresh rate information FI based on a clock signal included in the control signal CS. However, this is merely an example, and the invention is not limited thereto. The refresh rate calculator 410 can generate the refresh rate information FI in various ways.

[0106] According to an embodiment, the refresh rate calculator 410 may be omitted when an external device (e.g., a processor) provides refresh rate information FI or when refresh rate information FI is included in the control signal CS.

[0107] The grayscale calculator 420 can generate (or detect) grayscale information GI for a target image based on input image data IDATA. For example, the grayscale calculator 420 can generate grayscale information GI (or average grayscale values) by extracting grayscale values ​​from the input image data IDATA or by averaging the grayscale values. However, this is only an example, and the invention is not limited thereto. The grayscale calculator 420 can generate grayscale information GI in various ways.

[0108] The brightness calculator 430 can detect the light characteristics of an image based on refresh rate information (FI) and grayscale information (GI).

[0109] For example, in one embodiment, the brightness calculator 430 can detect the signal waveform of the image displayed by the display panel 110 based on refresh rate information FI and grayscale information GI. Here, the signal waveform can be compared with... Figure 3A The curves showing the actual brightness are the same or similar. For example, the brightness calculator 430 can calculate the peak brightness and / or average brightness of the image displayed by the display panel 110 based on refresh rate information FI and grayscale information GI or based on the signal waveform.

[0110] The brightness calculator 430 can determine the threshold TV based on refresh rate information FI and grayscale information GI (see...). Figure 3B (or the first threshold).

[0111] In an embodiment, the brightness calculator 430 can determine the threshold at which transient flickering (e.g., user-perceived flashing) is perceived by the user when switching refresh rates and displaying images.

[0112] For example, in an embodiment, based on the light characteristic information (e.g., signal waveform, peak brightness, or average brightness) of the image currently displayed by the display device 100 (or display panel 110), the brightness calculator 430 can determine, based on refresh rate information FI and grayscale information GI, the threshold at which transient flash phenomenon (e.g., flickering perceived by the user) is perceived by the user at the time point when the refresh rate is switched.

[0113] In an embodiment, the brightness calculator 430 may use a pre-stored lookup table (LUT) to determine a threshold. The lookup table may include thresholds based on the image's optical characteristics (e.g., signal waveform, peak brightness, or average brightness), refresh rate information FI, and grayscale information GI. The thresholds included in the lookup table may be experimentally determined based on the image's optical characteristics, refresh rate, and grayscale values, but this is merely an example, and the invention is not limited thereto.

[0114] In an embodiment, the brightness calculator 430 can calculate a predicted flash brightness value based on refresh rate information FI and grayscale information GI, or based on the light characteristic information of the image. For example, the brightness calculator 430 can use an activation function (or algorithm) to calculate the flash brightness value, which outputs the predicted flash brightness value for the refresh rate information FI and grayscale information GI, but the invention is not limited thereto.

[0115] The brightness calculator 430 compares the flash brightness value with a threshold and generates target brightness data CID based on the comparison result. Here, the target brightness data CID can represent the adjusted brightness or brightness adjustment ratio, making the flickering phenomenon imperceptible.

[0116] In an embodiment, when the maximum value of the flash brightness of the target image is greater than or equal to a threshold, the brightness calculator 430 can generate target brightness data CID to temporarily reduce the brightness of the display device 100.

[0117] For example, refer to Figure 5 When the display device 100 changes its refresh rate from a first refresh rate RR1 to a second refresh rate RR2 to display an image with a first brightness L1, the brightness calculator 430 can generate target brightness data CID for adjusting the image brightness to a second brightness L2 different from the first brightness L1 in the first frame (or at least one frame FRS including the first frame) of the second cycle P2 driven by the second refresh rate RR2. Here, when the second refresh rate RR2 is less than the first refresh rate RR1, the second brightness L2 can be lower than the first brightness L1. In the following, the first refresh rate RR1 can be approximately 120Hz, and the second refresh rate RR2 can be approximately 80Hz. For example, the target brightness data CID can have a ratio of the second brightness L2 to the first brightness L1, a brightness adjustment ratio, or values ​​corresponding to them.

[0118] For example, in the embodiments and reference Figure 6 The brightness calculator 430 can be based on the first refresh rate RR1 and the average gray level value (e.g., with...). Figure 5 The brightness calculator 430 calculates the first peak brightness L_PK1 (or first maximum brightness) in the first period P1 based on the gray level value corresponding to the first brightness L1. The first brightness peak L_PK1 can be the peak value based on the time of the image. In addition, the brightness calculator 430 can calculate the second peak brightness L_PK2 (or second maximum brightness) in the second period P2 based on the second refresh rate RR2 and the average gray level value.

[0119] In an embodiment, during the switching from a first refresh rate RR1 to a second refresh rate RR2, when the value of the flash brightness is determined or predicted to be greater than or equal to a threshold, the brightness calculator 430 can adjust the peak brightness of the first frame FR1 of the second period P2 to be between the first peak brightness L_PK1 of the first refresh rate RR1 according to the first period P1 and the second peak brightness L_PK2 of the second refresh rate RR2 according to the second period P2.

[0120] For example, the peak brightness of the first frame FR1 of the second period P2 can be in the range of approximately 85% to approximately 97% of the second peak brightness L_PK2. As the difference between the first refresh rate RR1 and the second refresh rate RR2 increases, or as the difference between the first peak brightness L_PK1 and the second peak brightness L_PK2 increases, the peak brightness of the first frame FR1 of the second period P2 can decrease. As an example, the brightness calculator 430 can determine the value of the peak brightness of the first frame FR1 of the second period P2 by applying a weighting function to the difference. When the peak brightness of the first frame FR1 of the second period P2 is less than approximately 85% of the second peak brightness L_PK2, a decrease in brightness may occur or be perceived in the second period P2.

[0121] For example, the peak brightness of the first frame FR1 in the second period P2 can be equal to the average of the first peak brightness L_PK1 and the second peak brightness L_PK2, or it can be within approximately ±10% of the average. For example, as the difference between the first refresh rate RR1 and the second refresh rate RR2 increases, or as the difference between the first peak brightness L_PK1 and the second peak brightness L_PK2 increases, the peak brightness of the first frame FR1 in the second period P2 can be less than the average of the first peak brightness L_PK1 and the second peak brightness L_PK2. When the peak brightness of the first frame FR1 in the second period P2 is less than approximately -10% of the average, a decrease in brightness may occur or be perceived in the second period P2.

[0122] In this embodiment, the brightness control signal generator 440 can generate a brightness control signal LCS based on the target brightness data CID.

[0123] For example, in one embodiment, the brightness control signal generator 440 can determine a compensation value or compensation ratio for the input image data IDATA (or image data DATA) or the grayscale values ​​included therein, based on the target brightness data CID. The compensation value or compensation ratio can be included in the brightness control signal LCS. In this case, the timing controller 124 can convert the input image data IDATA into image data DATA by reflecting the compensation value or compensation ratio. That is, compensated image data can be generated based on the compensation value or compensation ratio.

[0124] As another example, the brightness control signal generator 440 can determine the compensation value or compensation ratio of the gamma voltage based on the target brightness data CID. In this case, the data driver 122 can generate the gamma voltage by reflecting the compensation value or compensation ratio, and use the gamma voltage to generate a data signal corresponding to the image data DATA.

[0125] In one embodiment, when the maximum flash brightness of the target image is less than a threshold, the brightness calculator 430 may not generate target brightness data CID. In this case, the brightness control signal generator 440 may not generate a separate control signal (e.g., brightness control signal LCS). However, the invention is not limited thereto. For example, in another embodiment, when the maximum flash brightness of the target image is less than a threshold, the brightness calculator 430 may generate target brightness data CID corresponding to the original brightness (e.g., first brightness L1), and the brightness control signal generator 440 may generate a brightness control signal LCS to maintain the original brightness.

[0126] After performing brightness adjustment on the first frame FR1 of the second period P2, the brightness calculator 430 can detect the light characteristic information of the second frame FR2 of the second period P2, determine the threshold, and calculate the value of the flash brightness.

[0127] For example, when the maximum flash brightness of the target image in the second frame FR2 of the second period P2 is less than a threshold, the brightness calculator 430 may not generate the target brightness data CID, and the brightness control signal generator 440 may not generate the brightness control signal LCS. In this embodiment, in the frame following the first frame of the second period P2 (e.g., the second frame FR2), an image with a first brightness L1 or a second peak brightness L_PK2 according to the second refresh rate RR2 of the second period P2 can be displayed.

[0128] As another example, when the maximum value of the flash brightness of the target image in the second frame FR2 of the second period P2 is greater than or equal to the threshold, the brightness calculator 430 can generate target brightness data CID for adjusting the brightness of the second frame FR2 in the same way as the process of adjusting the brightness of the first frame FR1 of the second period P2.

[0129] In an embodiment, the brightness control signal generator 440 can adjust the brightness of the second frame FR2 of the second period P2 to be between the brightness of the first frame FR1 of the second period P2 and the brightness of the second period P2 (i.e., the first brightness L1). For example, the brightness control signal generator 440 can adjust the peak brightness of the second frame FR2 of the second period P2 to be between the peak brightness of the first frame FR1 of the second period P2 and the second peak brightness L_PK2, based on the second refresh rate RR2 of the second period P2. For example, the peak brightness of the second frame FR2 of the second period P2 can be about 85% to about 97% of the second peak brightness L_PK2. For example, the peak brightness of the second frame FR2 of the second period P2 can be equal to the average of the peak brightness of the first frame FR1 and the second peak brightness L_PK2, or can be within about ±10% of the average. The peak brightness of the second frame FR2 can be greater than or equal to the first peak brightness. Through the above processing, if necessary, the brightness of frames after the second frame FR2 of the second period P2 (e.g., the third frame, etc.) can also be adjusted.

[0130] As described above, the image controller 125 can detect the light characteristic information of the image based on the input image data IDATA and the control signal CS, compare the value of the flash brightness predicted based on the light characteristic information with a threshold TV, and adjust the brightness of the first frame FR1 (and the second frame FR2) of the second cycle P2 displayed when the refresh rate is switched. Therefore, even when the refresh rate is switched, transient flash phenomena perceived by the user can be prevented (e.g., eliminated) and visibility can be improved.

[0131] In the embodiments and reference Figure 4 It has been explained that the optical characteristics, threshold, flash brightness value, and target brightness data CID of an image are calculated sequentially based on refresh rate information FI and grayscale information GI, but the present invention is not limited thereto. For example, as the refresh rate changes from a first refresh rate RR1 to a second refresh rate RR2, the brightness adjustment ratio for each frame can be stored as a lookup table. In this case, the image controller 125 can determine the brightness adjustment ratio (or target brightness data CID) for each frame based on the refresh rate information FI and the lookup table. For example, the first brightness adjustment ratio for the first frame FR1 can be stored in the lookup table, and the image controller 125 can adjust the brightness of the first frame based on the first brightness adjustment ratio. For example, when the difference or ratio between the first refresh rate and the second refresh rate is greater than a reference value, the first brightness adjustment ratio for the first frame and the second brightness adjustment ratio for the second frame can be stored in the lookup table, and the image controller 125 can adjust the brightness of the second frame based on the second brightness adjustment ratio.

[0132] Figure 8 and Figure 9This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment. Figure 8 The average brightness for each frame is shown, and Figure 9 The actual brightness (or the corresponding brightness data LDATA) is shown. The fifth refresh rate RR5 can be greater than the fourth refresh rate RR4, and the third brightness L3 can be greater than the first brightness L1. In the following text, the fourth refresh rate RR4 can be 120Hz, and the fifth refresh rate RR5 can be 80Hz.

[0133] In the embodiments and reference Figure 4 , Figure 8 and Figure 9 In response to the refresh rate switching from the fourth cycle P4 to the fifth cycle P5 (e.g., immediately following the fourth cycle P4), the perceived brightness can decrease instantaneously. When the perceived brightness is less than or equal to a second threshold, even if the average brightness of the displayed image is the same when switching refresh rates, flicker (a decrease in brightness) can be perceived by the user at the instant of the refresh rate switch. Here, the second threshold can refer to a reference value for the brightness at which the user can perceive flicker (a decrease in brightness) when switching refresh rates.

[0134] In this embodiment, the brightness calculator 430 can determine the second threshold based on the refresh rate information FI and the grayscale information GI.

[0135] In an embodiment, when the maximum value of the flash brightness of the target image is less than the second threshold, the brightness calculator 430 can generate target brightness data CID to temporarily increase the brightness of the display device 100.

[0136] For example, in the embodiments and reference Figure 9 When the display device 100 changes the refresh rate from the fourth refresh rate RR4 to the fifth refresh rate RR5 to display an image with a first brightness L1, the brightness calculator 430 can generate target brightness data CID to adjust the brightness of the image to a third brightness L3 that is higher than the first brightness L1 in the first frame (or at least one frame FRS including the first frame) of the fifth cycle P5 driven by the fifth refresh rate RR5.

[0137] In an embodiment, during the switching from the fourth refresh rate RR4 to the fifth refresh rate RR5, when the value of the flash brightness is determined or predicted to be less than the second threshold, the brightness calculator 430 can adjust the peak brightness of the first frame FR1 of the fifth cycle P5 to be between the fourth peak brightness L_PK4 of the fourth refresh rate RR4 according to the fourth cycle P4 and the fifth peak brightness L_PK5 of the fifth refresh rate RR5 according to the fifth cycle P5.

[0138] For example, the peak brightness of the first frame FR1 of the fifth period P5 can be approximately 103% to approximately 117% of the fifth peak brightness L_PK5. For instance, the peak brightness of the first frame FR1 of the fifth period P5 can increase as the difference between the fourth refresh rate RR4 and the fifth refresh rate RR5 increases, or as the difference between the fourth peak brightness L_PK4 and the fifth peak brightness L_PK5 increases. As an example, the brightness calculator 430 can determine the peak brightness value of the first frame FR1 of the fifth period P5 by applying a weighting function to the difference.

[0139] For another example, the peak brightness of the first frame FR1 of the fifth cycle P5 can be equal to the average of the fourth peak brightness L_PK4 and the fifth peak brightness L_PK5, or it can be within approximately ±10% of the average. For example, as the difference between the fourth refresh rate RR4 and the fifth refresh rate RR5 increases, or as the difference between the fourth peak brightness L_PK4 and the fifth peak brightness L_PK5 increases, the peak brightness of the first frame FR1 of the fifth cycle P5 can be greater than the average of the fourth peak brightness L_PK4 and the fifth peak brightness L_PK5.

[0140] In one embodiment, when the maximum flash brightness of the target image is greater than or equal to a second threshold, the brightness calculator 430 may not generate target brightness data CID. In this case, the brightness control signal generator 440 may not generate a separate control signal (e.g., a brightness control signal LCS). However, the invention is not limited thereto. For example, in another embodiment, when the maximum flash brightness of the target image is greater than or equal to the second threshold, the brightness calculator 430 may generate target brightness data CID corresponding to the original brightness (e.g., a first brightness L1), and the brightness control signal generator 440 may generate a brightness control signal LCS to maintain the original brightness.

[0141] With regulation Figure 7 The brightness of the second frame FR2 in the fifth cycle P5 is similar, and the brightness of the second frame FR2 in the fifth cycle P5 can also be adjusted.

[0142] Figure 10 and Figure 11 This is a timing diagram illustrating the change in brightness according to the image refresh rate, based on an embodiment. Figure 10 The average brightness for each frame is shown, and Figure 11 The actual brightness (or the brightness data LDATA corresponding to the actual brightness) is shown.

[0143] In the embodiments and reference Figure 4 , Figure 10 and Figure 11 The image controller 125 can generate a brightness control signal LCS to control the brightness and refresh rate of the image. Figure 10 and Figure 11 The embodiments can be related to Figure 5 and Figure 6 The implementation differs in that it additionally controls the refresh rate. Besides controlling the refresh rate, Figure 10 and Figure 11 The embodiments can be related to Figure 5 and Figure 6 The embodiments are substantially the same or similar. Therefore, redundant descriptions will not be repeated.

[0144] In an embodiment, when the difference or ratio between the first refresh rate RR1 and the second refresh rate RR2 is greater than a reference value, the image controller 125 may additionally adjust the refresh rate in addition to brightness during the third cycle P3 between the first cycle P1 and the second cycle P2.

[0145] In an embodiment, when the maximum value of the flash brightness of the target image is greater than or equal to a threshold, the brightness calculator 430 can generate target brightness data CID to temporarily reduce the brightness of the display device 100.

[0146] For example, refer to Figure 10 When the display device 100 changes its refresh rate from a first refresh rate RR1 to a second refresh rate RR2 to display an image with a first brightness L1, the brightness calculator 430 can generate target brightness data CID such that the image with the second brightness L2 is displayed at a third refresh rate RR3 during a third period P3 (or bridging period) between the first period P1 and the second period P2. Here, the third refresh rate RR3 can have a value between the first refresh rate RR1 and the second refresh rate RR2. For example, the first refresh rate RR1 can be approximately 120Hz, the second refresh rate RR2 can be 80Hz, and the third refresh rate RR3 can be a value greater than approximately 80Hz and less than approximately 120Hz (e.g., 100Hz).

[0147] According to an embodiment, the brightness calculator 430 can control the value of the third refresh rate RR3 based on the difference between a threshold TV and the maximum value of the flash brightness. For example, as the difference between the threshold TV and the maximum value of the flash brightness increases, the brightness calculator 430 can control the third refresh rate RR3 to have a larger value.

[0148] In the embodiments and reference Figure 11 Since the third refresh rate RR3 is greater than the second refresh rate RR2 and less than the first refresh rate RR1, the length of each frame FR_P3 in the third period P3 (shown as "t3") can be longer than the length of each frame FR_P2 in the second period P2 (shown as "t2") and shorter than the length of each frame FR_P1 in the first period P1 (shown as "t1").

[0149] In an embodiment, the brightness calculator 430 can adjust the peak brightness (i.e., the third peak brightness L_PK3) in the third cycle P3 to be between the first peak brightness L_PK1 according to the first refresh rate RR1 of the first cycle P1 and the second peak brightness L_PK2 according to the second refresh rate RR2 of the second cycle P2. The third peak brightness L_PK3 can be compared with a reference... Figure 6 The method described for determining the peak brightness of the first frame FR1 of the second period P2 is the same as that used to determine the peak brightness.

[0150] In an embodiment, the third period P3 may include multiple frames. For example, the third period P3 may include two or fewer frames. The peak brightness in the multiple frames of the third period P3 may be the same, but the invention is not limited thereto. For example, in another embodiment, compared with reference to... Figure 7 The peak brightness of the first frame FR1 of the second period P2 is similar to that of the second frame FR2, and the peak brightness of the frames in the third period P3 can be gradually increased.

[0151] As described above, when the refresh rate changes from the first refresh rate RR1 to the second refresh rate RR2 to display an image, the image controller 125 can adjust the refresh rate and brightness in a third cycle P3 between the first cycle P1 driven by the first refresh rate RR1 and the second cycle P2 driven by the second refresh rate RR2.

[0152] Figure 12 This is a block diagram illustrating an electronic device according to an embodiment.

[0153] In the embodiments and reference Figure 12 The electronic device 1000 may include a processor 1010, a memory device 1020, a storage device 1030, an input / output device 1040, a power supply 1050, and a display device 1060. In this case, the display device 1060 may be... Figure 1 The electronic device 100 is a display device. Furthermore, the electronic device 1000 may also include several ports capable of communicating with video cards, sound cards, memory cards, and Universal Serial Bus (USB) devices, or with other systems. In embodiments, the electronic device 1000 may be implemented as a television set, a tablet PC, a navigation device, a smartphone, a mobile phone, a video phone, an e-book reader, a desktop PC, a laptop PC, a netbook computer, a workstation, a server, a personal digital assistant (PDA), a portable multimedia player (PMP), a Moving Image Experts Group Audio Layer 3 (MP3) player, a medical device, a camera, or a wearable device, etc.

[0154] Processor 1010 can perform specific calculations or tasks. According to one embodiment, processor 1010 can be a microprocessor, a central processing unit, or an application processor, etc. Processor 1010 can be connected to other components via address buses, control buses, and data buses, etc. According to an embodiment, processor 1010 can also be connected to an expansion bus, such as a peripheral component interconnect (PCI) bus.

[0155] According to an embodiment, the processor 1010 can change the image refresh rate.

[0156] The memory device 1020 can store data necessary for the operation of the electronic device 1000. For example, the memory device 1020 may include non-volatile memory devices such as EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, PRAM (Phase Change Random Access Memory), RRAM (Resistive Random Access Memory), NFGM (Nano Floating Gate Memory), PoRAM (Polymer Random Access Memory), MRAM (Magnetic Random Access Memory), or FRAM (Ferroelectric Random Access Memory) devices and / or volatile memory devices such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), or mobile DRAM devices.

[0157] Storage device 1030 may include solid-state drive (SSD), hard disk drive (HDD), or optical disc read-only memory (CD-ROM), etc.

[0158] Input / output device 1040 may include input devices such as a keyboard, keypad, touchpad, touchscreen, and mouse, and output devices such as a speaker and printer. According to an embodiment, display device 1060 may be included in input / output device 1040.

[0159] The power supply 1050 (or power supply device) can supply the power required to operate the electronic device 1000. For example, the power supply 1050 may be a power management integrated circuit (PMIC).

[0160] In one embodiment, the display device 1060 may display an image corresponding to the visual information of the electronic device 1000. In this case, the display device 1060 may be an organic light-emitting display device or a quantum dot light-emitting display device, but the present invention is not limited thereto. In another embodiment, the display device 1060 may be connected to other components via a bus or other communication link.

[0161] The display device and electronic device according to the embodiments can control the brightness of an image by comparing the flash brightness of an image calculated based on input image data with a threshold. Therefore, even when switching the image refresh rate of the display device, transient flashes (or flickering) perceived by the user can be prevented or eliminated. Thus, visibility can be improved.

[0162] Example embodiments have been disclosed herein, and although specific terminology has been used, these terms are used and interpreted in a general and descriptive sense only, and not for limiting purposes. In some instances, as will be apparent to those skilled in the art, features, characteristics, and / or elements described in connection with specific embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless specifically indicated otherwise. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. Thus, although various embodiments have been described above, those skilled in the art will appreciate that various modifications, additions, and substitutions are possible without departing from the scope and spirit of the invention.

Claims

1. A display device, wherein, The display device includes: Display panel, including pixels and displaying images; and A driver converts input image data into image data, generates a data signal based on the image data, and provides the data signal to the pixel according to the refresh rate. Specifically, when the refresh rate is changed from a first refresh rate to a second refresh rate to display an image with a first brightness, the driver adjusts the brightness of the first frame of the image displayed at the second refresh rate to a second brightness that is different from the first brightness.

2. The display device according to claim 1, wherein, When the second refresh rate is less than the first refresh rate, the driver reduces the second brightness to below the first brightness, and In response to the change in refresh rate, the driver changes the duty cycle, which represents the ratio of the time the pixel emits light during a frame, and the driver changes the peak brightness according to the time of the image.

3. The display device according to claim 2, wherein, The driver adjusts the peak brightness to be between a first peak brightness according to the first refresh rate and a second peak brightness according to the second refresh rate, based on the time of the image in the first frame.

4. The display device according to claim 3, wherein, The peak brightness of the first frame is in the range of 85% to 97% of the second peak brightness, or The peak brightness of the first frame is within ±10% of the average of the first peak brightness and the second peak brightness.

5. The display device according to claim 3, wherein, The driver selects one of a plurality of gamma voltages based on the grayscale value of the image data for the pixel, and outputs the selected gamma voltage as the data signal, and sets the plurality of gamma voltages in the first frame to be different from the plurality of gamma voltages for the second peak brightness.

6. The display device according to claim 3, wherein, The driver converts the input image data into image data based on the refresh rate and applies weights to generate image data for the first frame.

7. The display device according to claim 2, wherein, The driver drives the display panel to display the image with the first brightness in a second frame following the first frame.

8. The display device according to claim 2, wherein, When the difference between the first refresh rate and the second refresh rate is greater than a reference value, the driver adjusts the brightness of the second frame after the first frame to be between the first brightness and the second brightness.

9. The display device according to claim 1, wherein, When the second refresh rate is less than the first refresh rate, the driver increases the second brightness to a level higher than the first brightness.

10. An electronic device, wherein, The electronic device includes: The processor provides input image data; and A display device displays an image having a first brightness corresponding to the input image data. Wherein, when the processor changes the refresh rate of the image from a first refresh rate to a second refresh rate, the display device displays the image at a second brightness different from the first brightness during at least one frame, and displays the image at the first brightness after the at least one frame.

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