Display device
By employing a power supply unit to control different driving voltages for varying unit block sizes in central and peripheral regions, the display device addresses power and image quality issues, achieving reduced power consumption and improved contrast and resolution.
Patent Information
- Application Number
- JP2023216349
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2023-09-08
- Filing Date
- 2023-12-22
- Publication Date
- 2025-10-14
- Estimated Expiration
- 2043-12-22
AI Technical Summary
Conventional liquid crystal display devices face challenges in balancing power consumption, resolution, and contrast ratio due to uniform unit block sizes in local dimming methods, leading to increased manufacturing costs, heat generation, and reduced image quality.
A display device with a power supply unit controlling different driving voltages for unit blocks of varying sizes in central and peripheral regions, reducing LED count and optimizing LED arrangement to enhance resolution and contrast.
This approach reduces power consumption and improves image quality by minimizing unnecessary LED usage and enhancing contrast in peripheral areas, resulting in better image resolution and contrast ratio.
Smart Images

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Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a display device, and more particularly to a display device with local dimming. [Background technology]
[0002] 2. Description of the Related Art An active matrix liquid crystal display device displays moving images using thin film transistors (hereinafter referred to as "TFTs") as switching elements.
[0003] Liquid crystal display devices can be made smaller than cathode ray tubes (CRTs), and are rapidly replacing cathode ray tubes in applications such as portable information devices, office equipment, and computer displays, as well as televisions.
[0004] Transmissive liquid crystal display devices, which account for the majority of liquid crystal display devices, display images by controlling an electric field applied to a liquid crystal layer and modulating light incident from a backlight unit.
[0005] Meanwhile, backlight dimming methods have been proposed to reduce the power consumption of backlight units. Local dimming, one of the backlight dimming methods, can improve contrast by locally controlling the brightness of the display surface within one frame period.
[0006] The local dimming method separates input image data into virtual unit blocks divided into a matrix on the display screen of an LCD panel, derives a representative value of the input image data for each unit block, and adjusts a dimming value for each block according to the representative value for each block to control the brightness of the light source of the backlight unit for each block.
[0007] In the conventional method, all unit blocks are arranged with a uniform size. In order to improve the dimming resolution, it is advantageous for the size of the unit blocks to be small.
[0008] However, when the size of the unit block is reduced, the LEDs must be arranged more densely, which increases the number of LEDs, resulting in problems such as increased manufacturing costs, increased power consumption, and increased heat generation.
[0009] Conversely, if the size of the unit block is increased, the resolution decreases, resulting in a problem of a decrease in the contrast ratio at the periphery of the image.
[0010] Also, while the total number of LEDs can be maintained, only the large unit blocks can be divided into smaller ones, but in this case, the number of LEDs in each unit block decreases, resulting in a problem of reduced resolution. Summary of the Invention [Problem to be solved by the invention]
[0011] The present disclosure aims to reduce power consumption and improve resolution and contrast ratio by implementing a unit block size for dimming in an area that a user recognizes as a main area smaller.
[0012] The present disclosure aims to realize a display panel in which the unit blocks in the central region and the peripheral region other than the central region have different sizes. [Means for solving the problem]
[0013] A display device according to an embodiment of the present disclosure includes a power supply unit, a display panel that outputs an image, a backlight unit including a plurality of unit blocks that provide light to the display panel, and a backlight dimming controller that controls light output from the backlight unit to correspond to the image output through the display panel, wherein each of the plurality of unit blocks includes a plurality of LEDs, and an entire area of the display panel is divided into a first local area including a plurality of first unit blocks and a second local area including a plurality of second unit blocks, and the power supply unit can supply a first driving voltage to the first unit blocks of the first local area and a second driving voltage different from the first driving voltage to the second unit blocks of the second local area. [Effects of the Invention]
[0014] According to the present disclosure, the number of LEDs can be reduced compared to when the entire screen area is configured with unit blocks of the same size, thereby saving power consumption.
[0015] Furthermore, by designing the size of the unit block in the central area that is perceived by the viewer to be small, not only is the resolution increased, but the contrast ratio in the peripheral area of the displayed image is improved, resulting in good image quality. [Brief explanation of the drawings]
[0016] [Figure 1] FIG. 1 is a diagram illustrating a display device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a block diagram showing the configuration of the display device of FIG. [Figure 3] FIG. 3 is an example of an internal block diagram of the control unit of FIG. [Figure 4] FIG. 4 is an internal block diagram of the power supply and display of FIG. [Figure 5] FIG. 5 is a diagram showing an example of the arrangement of a liquid crystal display panel and a light source in the case of a direct type backlight unit. [Figure 6]FIG. 6 is a diagram showing a case where a plurality of unit blocks corresponding to a screen according to the prior art have the same size. [Figure 7] FIG. 7 is a diagram illustrating a case where unit blocks constituting a plurality of local areas on a screen have different sizes according to an embodiment of the present disclosure. [Figure 8] FIG. 8 is a diagram illustrating a case where unit blocks constituting a plurality of local areas on a screen have different sizes according to an embodiment of the present disclosure. [Figure 9] FIG. 9 is a diagram illustrating a configuration of a unit block of a screen having a dual structure according to an embodiment of the present disclosure. [Figure 10A] FIG. 10A is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the dual structure of FIG. [Figure 10B] FIG. 10B is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the dual structure of FIG. [Figure 11] FIG. 11 is a diagram illustrating the configuration of a unit block of a screen having a dual structure according to another embodiment of the present disclosure. [Figure 12A] FIG. 12A is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the dual structure of FIG. [Figure 12B] FIG. 12B is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the dual structure of FIG. [Figure 13] FIG. 13 is a diagram illustrating the configuration of a unit block of a screen having a dual structure according to another embodiment of the present disclosure. [Figure 14] FIG. 14 is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the dual structure of FIG. [Figure 15] FIG. 15 is a diagram illustrating a screen having a dual structure according to another embodiment of the present disclosure. [Figure 16A]FIG. 16A is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the embodiment of FIG. [Figure 16B] FIG. 16B is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the embodiment of FIG. DETAILED DESCRIPTION OF THE INVENTION
[0017] The present specification will now be explained in more detail with reference to the drawings.
[0018] The suffixes "module" and "section" used in the following description for components are given merely to facilitate the preparation of the specification and do not themselves have any particular significance or role. Therefore, the terms "module" and "section" can be used interchangeably.
[0019] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.
[0020] The singular expression includes the plural expression unless the context clearly indicates otherwise.
[0021] In this application, the use of terms such as "comprises" or "having" is intended to specify the presence of any features, numbers, steps, operations, components, parts, or combinations thereof set forth in the specification, but is understood not to preclude the possible presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.
[0022] FIG. 1 is a diagram illustrating a display device according to an embodiment of the present disclosure.
[0023] Referring to the drawing, a display device 100 may include a display unit 180 .
[0024] Meanwhile, the display unit 180 can be implemented using any one of various panels.
[0025] In the present disclosure, the display unit 180 is assumed to include a liquid crystal display panel (LCD panel). Hereinafter, the display device 100 may be a liquid crystal display device.
[0026] Meanwhile, the display device 100 of FIG. 1 can be a monitor, a TV, a tablet PC, a mobile terminal, or the like.
[0027] FIG. 2 is a block diagram showing the configuration of the display device of FIG.
[0028] Referring to FIG. 2, the display device 100 may include a broadcast receiving unit 130, an external device interface unit 135, a storage unit 140, a user input interface unit 150, a control unit 170, a wireless communication unit 173, a display unit 180, an audio output unit 185, and a power supply unit 190.
[0029] The broadcast receiving unit 130 may include a tuner 131 , a demodulating unit 132 , and a network interface unit 133 .
[0030] The tuner 131 can select a specific broadcast channel in response to a channel selection command, and can receive a broadcast signal for the selected specific broadcast channel.
[0031] The demodulator 132 can separate the received broadcast signal into a video signal, an audio signal, and a data signal related to the broadcast program, and can restore the separated video signal, audio signal, and data signal into a form that can be output.
[0032] The network interface unit 133 may provide an interface for connecting the display apparatus 100 to a wired / wireless network including the Internet network.
[0033] The external device interface unit 135 can receive an application or an application list from a neighboring external device and transmit it to the control unit 170 or the storage unit 140 .
[0034] The external device interface unit 135 may provide a connection path between the display apparatus 100 and an external device. The external device interface unit 135 may receive one or more of video and audio output from an external device connected to the display apparatus 100 wirelessly or via a wire, and transmit the video and audio to the control unit 170.
[0035] The external device interface unit 135 may include a plurality of external input terminals, which may include an RGB terminal, one or more HDMI (High Definition Multimedia Interface) terminals, and a component terminal.
[0036] A video signal from an external device input via the external device interface unit 135 is output via the display unit 180. An audio signal from an external device input via the external device interface unit 135 is output via the audio output unit 185.
[0037] The external device that can be connected to the external device interface unit 135 may be any one of a set-top box, a Blu-ray player, a DVD player, a game console, a sound bar, a smartphone, a PC, a USB memory, and a home theater, but these are merely examples.
[0038] The storage unit 140 stores programs for signal processing and control in the control unit 170, and can store processed video, audio, or data signals.
[0039] In addition, the storage unit 140 can also function as a temporary storage for video, audio or data signals input from the external device interface unit 135 or the network interface unit 133, and can also store information about a specific image through a channel storage function.
[0040] The user input interface unit 150 can transmit a signal input by the user to the control unit 170 or transmit a signal from the control unit 170 to the user. For example, the user input interface unit 150 can receive and process control signals such as power on / off, channel selection, and screen setting from the remote control device 200 according to various communication methods such as Bluetooth, WB (Ultra Wideband), ZigBee, RF (Radio Frequency) communication method, or infrared (IR) communication method, or can process control signals from the control unit 170 to be transmitted to the remote control device 200.
[0041] In addition, the user input interface unit 150 can transmit to the control unit 170 control signals input from local keys (not shown) such as a power key, a channel key, a volume key, and a setting value.
[0042] The video signal processed by the control unit 170 is input to the display unit 180 and displayed as a video corresponding to the video signal. The video signal processed by the control unit 170 is also input to an external output device via the external device interface unit 135.
[0043] The audio signal processed by the control unit 170 is output as audio to the audio output unit 185. The audio signal processed by the control unit 170 is also input to an external output device via the external device interface unit 135.
[0044] In addition, the control unit 170 can control the overall operation of the display device 100 .
[0045] The control unit 170 controls the video signal or audio signal from an external device, such as a camera or video camera, input via the external device interface unit 135 to be output via the display unit 180 or the audio output unit 185 in response to an external device video playback command received via the user input interface unit 150.
[0046] Meanwhile, the control unit 170 may control the display unit 180 to display an image, for example, a broadcast image input through the tuner 131, an externally input image input through the external device interface unit 135, an image input through the network interface unit, or an image stored in the storage unit 140 may be displayed on the display unit 180. In this case, the image displayed on the display unit 180 may be a still image or a moving image, and may be a 2D image or a 3D image.
[0047] In addition, the control unit 170 can control the playback of content stored in the display device 100, received broadcast content, or externally input content, and the content can have various forms such as broadcast video, externally input video, audio file, still image, connected web screen, and document file.
[0048] The wireless communication unit 173 can communicate with an external device via wired or wireless communication, and can perform short-range communication with the external device.
[0049] To this end, the wireless communication unit 173 can support short-range communication using at least one of Bluetooth (registered trademark), BLE (Bluetooth Low Energy), RFID (Radio Frequency Identification), Infrared Data Association (IrDA), UWB (Ultra Wideband), ZigBee, NFC (Near Field Communication), Wi-Fi (Wireless-Fidelity), Wi-Fi Direct, and Wireless USB (Wireless Universal Serial Bus) technologies.
[0050] The display unit 180 can convert the video signal, data signal, OSD signal processed by the control unit 170 or the video signal, data signal, etc. received by the external device interface unit 135 into R, G, B signals, respectively, and generate driving signals.
[0051] Meanwhile, the display device 100 illustrated in FIG. 1 is merely one embodiment of the present disclosure, and some of the illustrated components may be integrated, added, or omitted depending on the specifications of the display device 100 actually implemented.
[0052] That is, two or more components may be integrated into one component, or one component may be subdivided into two or more components, as necessary.
[0053] Furthermore, the functions performed by each block are for the purpose of explaining the embodiments of the present disclosure, and the specific operations and devices do not limit the scope of the present disclosure.
[0054] The audio output unit 185 receives the signal that has been subjected to audio processing by the control unit 170 and outputs it as audio.
[0055] The power supply unit 190 supplies power to the entire display device 100. In particular, it can supply power to the control unit 170, which can be implemented in the form of a system on chip (SOC), the display unit 180 for displaying images, and the audio output unit 185 for outputting audio.
[0056] Specifically, the power supply unit 190 may include a converter that converts AC power into DC power, and a dc / dc converter that converts the level of the DC power.
[0057] The remote control device 200 sends the user input to the user input interface unit 150 .
[0058] For this purpose, the remote control device 200 can use Bluetooth, RF (Radio Frequency) communication, infrared (IR) communication, UWB (Ultra Wideband), ZigBee, etc. Also, the remote control device 200 can receive video, audio, or data signals output from the user input interface unit 150 and display or output them as audio on the remote control device 200.
[0059] FIG. 3 is an example of an internal block diagram of the control unit of FIG.
[0060] Referring to the drawings, the control unit 170 according to an embodiment of the present disclosure may include a demultiplexing unit 310, a video processing unit 320, a processor 330, an OSD generating unit 340, a mixer 345, a frame rate converting unit 350, and a formatter 360. In addition, the control unit 170 may further include an audio processing unit (not shown) and a data processing unit (not shown).
[0061] The demultiplexer 310 demultiplexes the input stream. For example, when an MPEG-2 TS is input, the demultiplexer 310 demultiplexes the input stream and separates it into video, audio, and data signals. Here, the stream signal input to the demultiplexer 310 may be a stream signal output from the tuner 110, the demodulator 120, or the external device interface 130.
[0062] The video processor 320 may perform video processing on the demultiplexed video signal, and may include a video decoder 325 and a scaler 335.
[0063] The video decoder 325 decodes the demultiplexed video signal, and the scaler 335 scales the resolution of the decoded video signal so that it can be output to the display unit 180 .
[0064] The video decoder 325 may include decoders for various standards, such as an MPEG-2 or H.264 decoder, a 3D video decoder for color and depth images, and a decoder for multi-point-of-view images.
[0065] The processor 330 may control the overall operation of the display device 100 or the control unit 170. For example, the processor 330 may control the tuner 110 to select (tune) an RF broadcast corresponding to a channel selected by a user or a pre-stored channel.
[0066] The processor 330 can also control the display device 100 according to a user command input via the user input interface unit 150 or an internal program.
[0067] The processor 330 can also control data transmission with the network interface unit 135 or the external device interface unit 130 .
[0068] In addition, the processor 330 can control the operations of the demultiplexer 310, the video processor 320, the OSD generator 340, and the like in the controller 170.
[0069] The OSD generator 340 generates an OSD signal independently or in response to a user input. For example, the OSD generator 340 may generate a signal for displaying various information in graphics or text on the screen of the display unit 180 based on the user input signal. The generated OSD signal may include various data such as a user interface screen of the display apparatus 100, various menu screens, widgets, icons, etc. The generated OSD signal may also include 2D or 3D objects.
[0070] Furthermore, the OSD generator 340 may generate a pointer that can be displayed on the display unit 180 based on a pointing signal input from the remote control device 200. In particular, such a pointer is generated in a pointing signal processor, and the OSD generator 340 may include such a pointing signal processor (not shown). Of course, the pointing signal processor (not shown) may not be included in the OSD generator 340 but may be provided separately.
[0071] The mixer 345 may mix the OSD signal generated by the OSD generator 340 with the decoded video signal that has been video-processed by the video processor 320. The mixed video signal is provided to the frame rate converter 350.
[0072] A frame rate converter (FRC) 350 can convert the frame rate of an input image, or alternatively, the frame rate converter 350 can directly output the image without additional frame rate conversion.
[0073] Meanwhile, a formatter 360 can change the format of an input video signal into a video signal suitable for display on a display and output the signal.
[0074] The formatter 360 can change the format of the video signal. For example, the format of the 3D video signal can be changed to any one of various 3D formats such as a side-by-side format, a top-down format, a frame sequential format, an interlaced format, a checker box format, etc.
[0075] Meanwhile, an audio processing unit (not shown) in the control unit 170 can perform audio processing on the demultiplexed audio signal, and for this purpose, the audio processing unit (not shown) can include various decoders.
[0076] Furthermore, an audio processing unit (not shown) in the control unit 170 can process bass, treble, volume adjustment, and the like.
[0077] A data processing unit (not shown) in the control unit 170 can perform data processing on the demultiplexed data signal. For example, if the demultiplexed data signal is an encoded data signal, it can decode it. The encoded data signal may be electronic program guide information including broadcast information such as the start time and end time of a broadcast program aired on each channel.
[0078] 3 is a block diagram for one embodiment of the present disclosure, and each component of the block diagram may be integrated, added, or omitted depending on the specifications of the control unit 170 actually implemented.
[0079] In particular, the frame rate converter 350 and the formatter 360 may not be provided within the control unit 170, but may be provided separately or as a single module.
[0080] FIG. 4 is an internal block diagram of the power supply unit and display module of FIG.
[0081] Referring to the drawing, a display module 180 based on a liquid crystal display panel (LCD panel) may include a liquid crystal display panel 210, a driving circuit unit 230, a backlight unit 250, and a backlight dimming control unit 510.
[0082] The LCD panel 210 includes a first substrate on which a number of gate lines (GL) and data lines (DL) are arranged crossing each other in a matrix form to display an image, thin film transistors and pixel electrodes connected thereto are formed in the crossing areas, a second substrate on which a common electrode is provided, and a liquid crystal layer formed between the first and second substrates.
[0083] The driving circuit unit 230 drives the liquid crystal display panel 210 according to control signals and data signals supplied from the control unit 170 of Fig. 1. To this end, the driving circuit unit 230 includes a timing controller 232, a gate driver 234, and a data driver 236.
[0084] The timing controller 232 receives control signals, R, G, B data signals, a vertical synchronization signal (Vsync), etc. from the control unit 170, controls the gate driver 234 and the data driver 236 in response to the control signals, rearranges the R, G, B data signals, and provides them to the data driver 236.
[0085] Under the control of the gate driver 234, the data driver 236, and the timing controller 232, scanning signals and video signals are supplied to the liquid crystal display panel 210 via the gate lines (GL) and the data lines (DL).
[0086] The backlight unit 250 supplies light to the LCD panel 210. To this end, the backlight unit 250 may include a plurality of light sources 252, a scan driver 254 that controls scanning of the light sources 252, and a light source driver 256 that turns the light sources 252 on and off.
[0087] The light transmittance of the liquid crystal layer is adjusted by an electric field formed between the pixel electrode and the common electrode of the liquid crystal display panel 210, and a predetermined image is displayed using light emitted from the backlight unit 250.
[0088] The power supply unit 190 may supply a common electrode voltage (Vcom) to the LCD panel 210 and a gamma voltage to the data driver 236. The power supply unit 190 may also supply a driving power source to the backlight unit 250 to drive the light source 252.
[0089] Meanwhile, the backlight unit 250 may be divided into a plurality of blocks and driven. The control unit 170 may control the display 180 to perform local dimming by setting a dimming value for each of the plurality of blocks. Specifically, the timing controller 232 outputs input image data (RGB) to the backlight dimming control unit 510, and the backlight dimming control unit 510 may calculate a dimming value for each of the plurality of blocks based on the input image data (RGB) received from the timing controller 232.
[0090] FIG. 5 is a diagram showing an example of the arrangement of a liquid crystal display panel and a light source in the case of a direct type backlight unit.
[0091] The liquid crystal display panel 210 is divided into a plurality of virtual blocks as shown in Fig. 5. In Fig. 5, the liquid crystal display panel 210 is divided equally into 16 blocks BL1 to BL16, but the present invention is not limited to this. Each of the plurality of blocks may include a plurality of pixels.
[0092] The backlight unit 250 may be implemented as a direct type.
[0093] The direct type backlight unit 250 has a structure in which a number of optical sheets and a diffusion plate are laminated below the liquid crystal display panel 210, and a number of light sources are arranged below the diffusion plate.
[0094] 5, the backlight unit 250 is divided into blocks BL1 to BL16 of the LCD panel 210 in a one-to-one correspondence. In this case, the brightness of light incident on the first block BL1 of the LCD panel 210 can be adjusted using a light source 252 included in the first block B1 of the backlight unit 250, which is disposed at a position corresponding to the first block BL1 of the LCD panel 210.
[0095] The light source 252 may be implemented as a light source such as a light emitting diode (LED). The light source 252 is turned on and off by receiving a light source drive signal LDS from a light source driver 256. The light source 252 adjusts the light intensity according to the amplitude of the light source drive signal LDS and adjusts the turn-on period according to the pulse width. The light source 252 adjusts the brightness of the light output according to the light source drive signal LDS.
[0096] The light source driver 256 may generate a light source drive signal LDS based on the dimming value of each block input from the backlight dimming controller 510 and output the generated signal to the light source 252. The dimming value of the block may be a value for implementing local dimming, which may be the brightness of light output by the light source 252.
[0097] FIG. 6 is a diagram showing a case where a plurality of unit blocks corresponding to a screen according to the prior art have the same size.
[0098] The brightness of each of the plurality of unit blocks 601 is individually controlled via the backlight unit 250 .
[0099] The screen display area 610 is an area where an image is output, and the backlight unit on area 630 is an area where the backlight unit 250 provides light for the image output of the screen display area 610 .
[0100] As in the case of Figure 6, when the size of the unit blocks is the same, the backlight unit on area 630 becomes larger than the screen display area 610, and light is provided to more unit blocks than necessary (12 unit blocks), resulting in wasted power consumption and a decrease in the contrast ratio in the peripheral area of the screen display area 610.
[0101] 7 and 8 are diagrams illustrating cases where unit blocks constituting a plurality of local areas on a screen have different sizes according to an embodiment of the present disclosure.
[0102] Hereinafter, a unit block may be a block corresponding to a unit area of the display panel 210 and may be a block that supplies light to the unit area of the display panel 210.
[0103] In particular, FIG. 7 illustrates a case where the screen is divided into two local areas, and FIG. 8 illustrates a case where the screen is divided into three local areas.
[0104] Referring to FIG. 7, the entire area of the screen is divided into a first local area 710 and a second local area 730.
[0105] The first local region 710 may include a plurality of first unit blocks, each of which may have the same size.
[0106] The second local region 730 may include a plurality of second unit blocks, each of which may have the same size.
[0107] The first local region 710 may be located in the center of the screen, and the second local region 730 may be located on the periphery of the screen. That is, the outer region of the entire screen other than the first local region 710 is the second local region 730.
[0108] The second local region 730 may be positioned in a manner surrounding the first local region 710 .
[0109] The first local region 710 is an important region that is mainly recognized by the viewer, and the second local region 730 is an unimportant region that is not so recognized by the viewer.
[0110] The size of the first unit block 711 may be smaller than the size of the second unit block 731. The size of the second unit block 731 may be the same as the size of the unit block 601 of FIG.
[0111] In FIG. 7, the screen display area 610 and the backlight unit on area 750 may be the same.
[0112] Since the size of the first unit block 711 constituting the first local region 710 is smaller than the size of the unit block 601 in FIG. 6, the size of the backlight unit-on region 750 (six unit blocks) can also be reduced.
[0113] That is, according to the embodiment of FIG. 7, the number of unit blocks that must be turned on to supply light to the screen display area 610 is reduced from 12 to 6 compared to the prior art of FIG.
[0114] This prevents waste of power consumption, and since the screen display area 610 and the backlight unit on area 750 are the same size, the resolution and contrast ratio of the periphery of the screen display area 610 are improved.
[0115] Referring to FIG. 8, the entire area of the screen is divided into a fourth local area 810, a fifth local area 830, and a sixth local area 850.
[0116] The fourth local region 810 may include a plurality of fourth unit blocks, the fifth local region 830 may include a plurality of fifth unit blocks, and the sixth local region 850 may include a plurality of sixth unit blocks.
[0117] Each of the plurality of fourth unit blocks may have the same size.
[0118] Each of the plurality of fifth unit blocks may have the same size.
[0119] Each of the sixth unit blocks may have the same size.
[0120] The fourth local region 810 may be located in the center of the screen, the fifth local region 830 may surround the fourth local region 810 , and the sixth local region 850 may surround the fifth local region 830 .
[0121] The size of the fourth unit block 811 may be smaller than the size of the fifth unit block 831 .
[0122] The size of the fifth unit block 831 may be smaller than the size of the sixth unit block 851 .
[0123] That is, the size of the unit block may increase from the center of the screen to the periphery.
[0124] FIG. 9 is a diagram illustrating a configuration of a unit block of a screen having a dual structure according to an embodiment of the present disclosure.
[0125] Referring to FIG. 9, the screen can have a dual structure like the embodiment of FIG.
[0126] That is, the entire area of the screen may include the first local area 710 and the second local area 730, which is an area other than the first local area 710.
[0127] Each of the plurality of first unit blocks 711 included in the first local region 710 may include nine LEDs (Light Emitting Diodes).
[0128] The first unit block 711 may include nine LEDs 901 arranged at regular intervals. The intervals between adjacent LEDs arranged in the horizontal direction of the first unit block 711 may be the same, and the second intervals between adjacent LEDs arranged in the vertical direction of the first unit block 711 may be the same.
[0129] Each of the plurality of second unit blocks 731 included in the second local region 730 may include 16 LEDs 903 .
[0130] The intervals between adjacent LEDs arranged in the horizontal direction of the second unit block 731 are the same, and the intervals between adjacent LEDs arranged in the vertical direction of the second unit block 731 are the same.
[0131] Furthermore, the interval between two horizontally or vertically adjacent LEDs of the first unit block 711 may be the same as the interval between two horizontally or vertically adjacent LEDs of the second unit block 731 .
[0132] As such, in the case of the double structure according to the embodiment of FIG. 9, the spacing between adjacent LEDs in the first block 711 is the same as the spacing between adjacent LEDs in the second block 731, but the number of LEDs included in the first block 711 may be smaller than the number of LEDs included in the second block 731.
[0133] This reduces the number of LEDs compared to when the entire screen area is made up of unit blocks of the same size, thereby saving power consumption.
[0134] Furthermore, by designing the size of the unit block in the central area that is perceived by the viewer to be small, not only is the resolution increased, but the contrast ratio in the peripheral area of the displayed image is improved, resulting in good image quality.
[0135] 10A and 10B are diagrams illustrating driving voltages and dimming signals provided to each local region according to the dual structure of FIG.
[0136] Referring to FIG. 10A, the power supply unit 190 may supply a first driving voltage VLED_A to the first unit block 711 and a second driving voltage VLED_B to the second unit block 731.
[0137] The magnitude of the second driving voltage VLED_B may be greater than the magnitude of the first driving voltage VLED_A.
[0138] As shown in FIG. 9, the first unit block 711 includes 9 LEDs, and the second unit block 731 includes 16 LEDs, so that the magnitude of the driving voltage supplied to each unit block is different.
[0139] For example, referring to FIG. 10B, if the voltage supplied to one LED is 5.7V, the magnitude of the first driving voltage VLED_A supplied to the first unit block 711 is 51.3V (9×5.7), and the magnitude of the second driving voltage VLED_B supplied to the second unit block 731 is 91.2V (16×5.7).
[0140] In this way, the driving voltages supplied to the first and second unit blocks 711 and 731 are different depending on the size difference between the first and second unit blocks 711 and 731.
[0141] Meanwhile, since the number of LEDs included in the first unit block 711 is smaller than the number of LEDs included in the second unit block 731, the brightness is reduced and brightness compensation is required.
[0142] The backlight dimming control unit 510 can calculate the amount of brightness reduction due to the reduction in the number of LEDs in the first unit block 711.
[0143] The backlight dimming control unit 510 may calculate a luminance compensation amount corresponding to the reduced number of LEDs in the first block 711. For example, as shown in FIG. 9, if the number of LEDs in the first block 711 is 9 and the number of LEDs in the second block 731 is 16, the backlight dimming control unit 510 may calculate a luminance compensation amount corresponding to 7 LEDs.
[0144] The backlight dimming control unit 510 may store a unit brightness compensation amount corresponding to one LED in advance. A memory (not shown) included in the backlight dimming control unit 510 or separately provided, or a storage unit 140 may store a unit brightness compensation amount corresponding to one LED in advance.
[0145] The backlight dimming control unit 510 can calculate the brightness compensation amount corresponding to seven LEDs using the stored unit brightness compensation amount.
[0146] The backlight dimming control unit 510 may store a luminance compensation amount corresponding to each unit block in advance in a memory, which may be included in the backlight dimming control unit 510 or may be provided separately.
[0147] The backlight dimming control unit 510 can read the luminance compensation amount of each unit block from the memory and transmit a dimming signal reflecting the read luminance compensation amount to the backlight unit 500. Thus, the luminance of each unit block is compensated.
[0148] For example, the backlight dimming control unit 510 may read the luminance compensation amount of the first block 711 from the memory and transmit the first dimming signal reflecting the read luminance compensation amount to the backlight unit 500 .
[0149] In another embodiment, the backlight dimming control unit 510 may calculate a first luminance value corresponding to the size of the first block unit 711 and a second luminance value corresponding to the size of the second block unit 731 .
[0150] The backlight dimming control unit 510 may obtain a value obtained by subtracting the first luminance amount from the second luminance amount as the luminance compensation amount.
[0151] The backlight dimming control unit 510 may adjust the dimming curve of each of the first unit blocks included in the first local region 710 to match the calculated brightness compensation amount.
[0152] The dimming curve may be a curve that indicates the characteristics of the dimming value of the unit block. The horizontal axis of the dimming curve may represent grayscale values from 0 to 255, and the vertical axis may represent dimming values from 0% to 100%.
[0153] The backlight dimming control unit 510 may generate a first dimming signal reflecting the calculated brightness compensation amount and transmit the generated first dimming signal to the backlight unit 250.
[0154] The first dimming signal may include a dimming value for controlling each of the plurality of first unit blocks.
[0155] The backlight dimming control unit 510 may adjust the dimming curve of each of the first unit blocks so that the luminance compensation amount (luminance increase) is reflected. The backlight dimming control unit 510 may adjust the dimming curve so that the dimming value increases compared to the same gray level.
[0156] The backlight dimming control unit 510 generates a second dimming signal and transmits the second dimming signal to the backlight unit 510 .
[0157] The second dimming signal may include a dimming value for controlling each of the plurality of second unit blocks.
[0158] FIG. 11 is a diagram illustrating the configuration of a unit block of a screen having a dual structure according to another embodiment of the present disclosure.
[0159] Referring to FIG. 11, the screen can have a dual structure like the embodiment of FIG.
[0160] That is, the entire area of the screen may include the first local area 710 and the second local area 730, which is an area other than the first local area 710.
[0161] Each of the plurality of first unit blocks 1110 included in the first local region 710 may include 16 LEDs 1111 .
[0162] Each of the plurality of second unit blocks 731 included in the second local region 730 may include 16 LEDs 903 .
[0163] The number of LEDs included in the first unit block 1110 may be the same as the number of LEDs included in the second unit block 731.
[0164] The intervals between two adjacent LEDs in the horizontal or vertical direction included in the first unit block 1110 are the same.
[0165] The intervals between two adjacent LEDs in the horizontal or vertical direction included in the second unit block 731 are the same.
[0166] The interval between two horizontally or vertically adjacent LEDs of the first unit block 1110 may be smaller than the interval between two horizontally or vertically adjacent LEDs of the second unit block 731 .
[0167] That is, the number of LEDs in the first unit block 1110 can be maintained while the spacing between two adjacent LEDs can be reduced, thereby reducing the size of the block.
[0168] Thus, in the case of the double structure according to the embodiment of FIG. 11, the number of LEDs included in the first unit block 1110 is the same as the number of LEDs included in the second unit block 731, but the spacing between adjacent LEDs in the first unit block 1110 may be smaller than the spacing between adjacent LEDs in the second unit block 731.
[0169] In this way, not only is the resolution increased by designing the size of the unit block in the central area that is perceived by the viewer to be small, but the contrast ratio in the peripheral area of the displayed image is improved, resulting in good image quality.
[0170] 12A and 12B are diagrams illustrating driving voltages and dimming signals provided to each local region according to the dual structure of FIG.
[0171] Referring to FIG. 12A, the power supply unit 190 may supply the second driving voltage VLED_B to the first unit block 1110 and the second driving voltage VLED_B to the second unit block 731.
[0172] That is, since the number of LEDs included in each of the first and second blocks 1110 and 731 is the same, the power supply unit 190 can supply the same driving voltage to each of the first and second blocks 1110 and 731.
[0173] For example, referring to FIG. 12B, when the voltage supplied to one LED is 5.7V, the magnitude of the first driving voltage VLED_A supplied to the first unit block 1110 is 91.2V (16×5.7), and the magnitude of the second driving voltage VLED_B supplied to the second unit block 731 is 91.2V (16×5.7).
[0174] In this way, even if there is a difference in size between the first unit block 1110 and the second unit block 731, the driving voltage supplied thereto can be the same.
[0175] Meanwhile, even if the number of LEDs included in the first block 1110 is the same as the number of LEDs included in the second block 731, the size of the first block 1110 is smaller than the size of the second block 731. Since the density of the LEDs in the first block 1110 increases the brightness, brightness compensation is necessary.
[0176] The backlight dimming control unit 510 may calculate a brightness compensation amount to be compensated for due to an increase in the number of LEDs of the first block 1110 compared to the second block 731 having the same size.
[0177] The backlight dimming control unit 510 may calculate a third luminance amount corresponding to the size of the first block unit 1110 and may calculate a second luminance amount corresponding to the size of the second block unit 731 .
[0178] The backlight dimming control unit 510 may obtain a value obtained by subtracting the second luminance amount from the third luminance amount as the luminance compensation amount.
[0179] The backlight dimming control unit 510 may adjust the dimming curve of each of the first unit blocks included in the first local region 710 to match the calculated brightness compensation amount.
[0180] The dimming curve may be a curve that indicates the characteristics of the dimming value of the unit block. The horizontal axis of the dimming curve may represent grayscale values from 0 to 255, and the vertical axis may represent dimming values from 0% to 100%.
[0181] The backlight dimming control unit 510 may generate a third dimming signal reflecting the calculated brightness compensation amount (brightness reduction amount) and transmit the generated third dimming signal to the backlight unit 250.
[0182] The third dimming signal may include a dimming value for controlling each of the plurality of first unit blocks.
[0183] The backlight dimming control unit 510 may adjust the dimming curve of each of the first unit blocks so that the luminance compensation amount is reflected. The backlight dimming control unit 510 may adjust the dimming curve so that the dimming value increases compared to the same gray level.
[0184] The backlight dimming control unit 510 generates a second dimming signal and transmits the second dimming signal to the backlight unit 510 .
[0185] The second dimming signal may include a dimming value for controlling each of the plurality of second unit blocks.
[0186] The backlight dimming control unit 510 may store a luminance compensation amount corresponding to each unit block in advance in a memory, which may be included in the backlight dimming control unit 510 or may be provided separately.
[0187] The backlight dimming control unit 510 can read the luminance compensation amount of each unit block from the memory and transmit a dimming signal reflecting the read luminance compensation amount to the backlight unit 500. Thus, the luminance of each unit block is compensated.
[0188] FIG. 13 is a diagram illustrating the configuration of a unit block of a screen having a dual structure according to another embodiment of the present disclosure.
[0189] Referring to FIG. 13, the screen can have a dual structure like the embodiment of FIG.
[0190] That is, the entire area of the screen may include the first local area 710 and the second local area 730, which is an area other than the first local area 710.
[0191] Each of the plurality of first unit blocks 1310 included in the first local region 710 may include nine LEDs 1311 .
[0192] Each of the plurality of second unit blocks 731 included in the second local region 730 may include 16 LEDs 903 .
[0193] The intervals between two adjacent LEDs in the horizontal or vertical direction included in the first unit block 1310 are the same.
[0194] The intervals between two adjacent LEDs in the horizontal or vertical direction included in the second unit block 731 are the same.
[0195] The interval between two horizontally or vertically adjacent LEDs of the first unit block 1310 may be smaller than the interval between two horizontally or vertically adjacent LEDs of the second unit block 731 .
[0196] That is, the number of LEDs in the first unit block 1110 is smaller than that in the second unit block 731, but the distance between two adjacent LEDs is reduced, so that the size of the block can be reduced.
[0197] Thus, in the case of the double structure according to the embodiment of FIG. 13, the number of LEDs included in the first unit block 1110 may be smaller than the number of LEDs included in the second unit block 731, and the spacing between adjacent LEDs in the first unit block 1310 may be smaller than the spacing between adjacent LEDs in the second unit block 731.
[0198] This reduces the number of LEDs compared to when the entire screen area is made up of unit blocks of the same size, thereby saving power consumption.
[0199] Furthermore, by designing the size of the unit block in the central area that is perceived by the viewer to be small, not only is the resolution increased, but the contrast ratio in the peripheral area of the displayed image is improved, resulting in good image quality.
[0200] Meanwhile, the type of the LED 1311 included in the first unit block 1310 may be different from the type of the LED 903 included in the second unit block 731.
[0201] The luminous efficiency of the LED 1311 included in the first unit block 1310 is better than the luminous efficiency of the LED 903 included in the second unit block 731 .
[0202] FIG. 14 is a diagram illustrating a driving voltage and a dimming signal provided to each local region according to the dual structure of FIG.
[0203] Referring to FIG. 14, the power supply unit 190 may supply a first driving voltage VLED_A to the first unit block 1310 and a second driving voltage VLED_B to the second unit block 731.
[0204] That is, since the number of LEDs included in each of the first and second blocks 1310 and 731 is the same, the power supply unit 190 can supply the same driving voltage to each of the first and second blocks 1310 and 731.
[0205] The magnitude of the second driving voltage VLED_B may be greater than the magnitude of the first driving voltage VLED_A.
[0206] For example, if the voltage supplied to one LED is 5.7V, the magnitude of the first driving voltage VLED_A supplied to the first unit block 1310 is 51.3V (9×5.7), and the magnitude of the second driving voltage VLED_B supplied to the second unit block 731 is 91.2V (16×5.7).
[0207] In this way, the driving voltages supplied are different depending on the size difference between the first unit block 1330 and the second unit block 731.
[0208] Meanwhile, since the number of LEDs included in the first unit block 1310 is smaller than the number of LEDs included in the second unit block 731, the brightness is reduced and brightness compensation is required. In another embodiment, the backlight dimming control unit 510 may calculate a fourth luminance value corresponding to the size of the first block unit 1310 and a second luminance value corresponding to the size of the second block unit 731.
[0209] The backlight dimming control unit 510 may obtain a value obtained by subtracting the fourth luminance amount from the second luminance amount as the luminance compensation amount.
[0210] The backlight dimming control unit 510 may generate a fourth dimming signal reflecting the calculated brightness compensation amount and transmit the generated fourth dimming signal to the backlight unit 250.
[0211] The backlight dimming control unit 510 may adjust the dimming curve of each of the first unit blocks included in the first local region 710 to match the calculated brightness compensation amount.
[0212] FIG. 15 is a diagram illustrating a screen having a dual structure according to another embodiment of the present disclosure.
[0213] Referring to FIG. 15, the entire area of the screen may include a first local area 1510 and a second local area 1530 other than the first local area 1510.
[0214] The first local region 1510 may be a central region of the screen, and the second local region 1510 may be an outer region surrounding the first local region 1510.
[0215] The first local region 1510 may include a plurality of first unit blocks, and the second local region 1530 may include a plurality of second unit blocks.
[0216] The size of each of the plurality of first block units 1511 and the size of each of the plurality of second block units 1531 may be the same.
[0217] The number of LEDs 1513 or the arrangement of the LEDs 1513 included in each of the plurality of first unit blocks 1511 may be different from the number of LEDs 1533 or the arrangement of the LEDs 1513 included in each of the plurality of second unit blocks 1531.
[0218] For example, the number of LEDs 1513 included in the first block 1511 may be 16, and the number of LEDs 1533 included in the second block 1531 may be 9. Thus, the spacing between the LEDs included in the first block 1511 may be smaller than the spacing between the LEDs included in the second block 1531.
[0219] In the embodiment of FIG. 15, the number and arrangement of the LEDs 1531 included in the first unit block 1511 may be different from the number and arrangement of the LEDs 1533 included in the second unit block 1531.
[0220] 16A and 16B are diagrams illustrating driving voltages and dimming signals provided to each local region according to the embodiment of FIG.
[0221] 16A and 16B, the power supply unit 190 may supply the second driving voltage VLED_B to the first unit block 1511 and the first driving voltage VLED_A to the second unit block 1531.
[0222] The magnitude of the second driving voltage VLED_B may be greater than the magnitude of the first driving voltage VLED_A.
[0223] As shown in FIG. 15, the first unit block 1511 includes 16 LEDs, and the second unit block 1531 includes 9 LEDs, so that the magnitude of the driving voltage supplied to each unit block is different.
[0224] For example, referring to FIG. 16B, when the voltage supplied to one LED is 5.7V, the magnitude of the first driving voltage VLED_B supplied to the first unit block 1511 is 91.2V (16×5.7), and the magnitude of the first driving voltage VLED_A supplied to the second unit block 1531 is 51.3V (9×5.7).
[0225] In this way, the driving voltages supplied are different depending on the size difference between the first unit block 1511 and the second unit block 1531.
[0226] Meanwhile, since the number of LEDs included in the first unit block 1511 is greater than the number of LEDs included in the second unit block 1531, the brightness is increased and brightness compensation is required.
[0227] The backlight dimming control unit 510 can calculate the amount of brightness compensation due to the fact that the number of LEDs in the first block 1511 is greater than that in the second block 1531 .
[0228] The backlight dimming control unit 510 can calculate the brightness compensation amount corresponding to the increased number of LEDs in the first unit block 1511.
[0229] For example, as shown in FIG. 15, if the number of LEDs in the first unit block 1511 is 16 and the number of LEDs in the second unit block 1531 is 9, the backlight dimming control unit 510 can calculate the brightness compensation amount corresponding to 7 LEDs.
[0230] The backlight dimming control unit 510 may store a unit brightness compensation amount corresponding to one LED in advance. A memory (not shown) included in the backlight dimming control unit 510 or separately provided, or a storage unit 140 may store a unit brightness compensation amount corresponding to one LED in advance.
[0231] The backlight dimming control unit 510 can calculate the brightness compensation amount corresponding to seven LEDs using the stored unit brightness compensation amount.
[0232] The backlight dimming control unit 510 may store a luminance compensation amount corresponding to each unit block in advance in a memory, which may be included in the backlight dimming control unit 510 or may be provided separately.
[0233] The backlight dimming control unit 510 can read the luminance compensation amount of each unit block from the memory and transmit a dimming signal reflecting the read luminance compensation amount to the backlight unit 500. Thus, the luminance of each unit block is compensated.
[0234] For example, the backlight dimming control unit 510 may read the luminance compensation amount of the first block 1511 from the memory and transmit the fifth dimming signal reflecting the read luminance compensation amount to the backlight unit 500 .
[0235] In another embodiment, the backlight dimming control unit 510 may calculate a first luminance value corresponding to the first unit block 1511 and a second luminance value corresponding to the second unit block 1531 .
[0236] The backlight dimming control unit 510 may obtain a value obtained by subtracting the first luminance amount from the second luminance amount as the luminance compensation amount.
[0237] The backlight dimming control unit 510 may adjust the dimming curve of each of the first unit blocks included in the first local region 1511 to match the calculated brightness compensation amount.
[0238] The dimming curve may be a curve that indicates the characteristics of the dimming value of the unit block. The horizontal axis of the dimming curve may represent grayscale values from 0 to 255, and the vertical axis may represent dimming values from 0% to 100%.
[0239] The backlight dimming control unit 510 may generate a fifth dimming signal reflecting the calculated brightness compensation amount and transmit the generated fifth dimming signal to the backlight unit 250.
[0240] The fifth dimming signal may include a dimming value for controlling each of the plurality of first unit blocks 1511.
[0241] The backlight dimming control unit 510 may adjust the dimming curve of each of the plurality of first unit blocks 1511 so that the luminance compensation amount (luminance reduction amount) is reflected. The backlight dimming control unit 510 may adjust the dimming curve so that the dimming value increases compared to the same gray level.
[0242] The backlight dimming control unit 510 generates a second dimming signal and transmits the second dimming signal to the backlight unit 510 .
[0243] The second dimming signal may include a dimming value for controlling each of the plurality of second unit blocks 1531.
[0244] In the double structure of the embodiment of Figure 15, the number of LEDs included in the first unit block 1511 is greater than the number of LEDs included in the second unit block 1531, which has the same size as the first unit block 1511, and the LEDs are more densely packed.
[0245] This not only improves the resolution in the central area that is primarily perceived by the viewer, but also improves the contrast in the peripheral areas of the displayed image, resulting in better image quality.
[0246] The present disclosure described above can be embodied as computer-readable code stored on a medium having a program recorded thereon. Computer-readable media include all types of storage devices that store data readable by a computer system. Examples of computer-readable media include hard disk drives (HDDs), solid-state disks (SSDs), silicon disk drives (SDDs), ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, and optical data storage devices.
[0247] The computer may also include a control unit 170 for the display device 100 .
Claims
1. 1. A display device, comprising: a power supply unit; a display panel that outputs video; a backlight unit including a plurality of unit blocks for providing light to the display panel; a backlight dimming control unit that controls light output from the backlight unit in accordance with the image output through the display panel; Including, Each of the plurality of unit blocks includes a plurality of LEDs, an entire area of the display panel is divided into a first local area including a plurality of first unit blocks and a second local area including a plurality of second unit blocks; the power supply unit supplies a first driving voltage to a first unit block of the first local region and a second driving voltage different from the first driving voltage to a second unit block of the second local region; The size of the first unit block is smaller than the size of the second unit block, the first local region is a central region of the entire region, the second local region is an outer region surrounding the central region, The number of LEDs included in the first unit block is the same as the number of LEDs included in the second unit block.
2. The display device of claim 1 , wherein a distance between adjacent LEDs included in the first block is different from a distance between adjacent LEDs included in the second block.
3. The display device of claim 1, wherein the backlight dimming control unit calculates a luminance compensation amount for the first sub-block and transmits a dimming signal reflecting the calculated luminance compensation amount to the backlight unit.
4. 4. The display device of claim 3, wherein the backlight dimming control unit calculates a first luminance amount corresponding to the first unit block, calculates a second luminance amount corresponding to the second unit block, and calculates a difference between the first luminance amount and the second luminance amount as the luminance compensation amount.
5. further comprising a memory for storing the luminance compensation amount corresponding to the first unit block; The display device of claim 3, wherein the backlight dimming control unit reads the luminance compensation amount from the memory and transmits the dimming signal reflecting the read luminance compensation amount to the backlight unit.
6. The display device of claim 2, wherein a distance between adjacent LEDs included in the first block is smaller than a distance between adjacent LEDs included in the second block.
7. The display device of claim 1 , wherein the luminous efficiency of the LEDs included in the first block is higher than the luminous efficiency of the LEDs included in the second block.
8. The display device of claim 1 , wherein the second driving voltage is greater than the first driving voltage.
Citation Information
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