KR102268047B1 - Video processing apparatus and method thereof - Google Patents

Abstract

The present specification relates to an image processing apparatus capable of reducing a flicker phenomenon of an image display device and a method therefor, and the image processing apparatus according to an embodiment of the present specification provides an image processing apparatus corresponding to each of a plurality of sub-pixels included in one pixel. In the image processing apparatus for outputting a pulse of one frame to each sub-pixel, the pulse of one frame is changed to a plurality of sub-pulses, the area of the plurality of sub-pulses is the same, and the pulse amplitude and the pulse width are different from each other The method may further include a data converter configured to convert the plurality of sub-pulses and output the converted plurality of sub-pulses as pulses of one frame to a corresponding pixel.

Description

Image processing apparatus and method thereof {VIDEO PROCESSING APPARATUS AND METHOD THEREOF}

The present invention relates to an image processing apparatus and a method therefor.

The video display device includes both an apparatus for receiving and displaying a broadcast or recording and reproducing a video and an apparatus for recording and reproducing audio. The image display device includes, for example, a television, a computer monitor, a projector, and a tablet. As the functions of such video display devices are diversified, in addition to broadcasting and playback of music or video files, these video display devices are in the form of multimedia devices equipped with complex functions such as taking pictures or videos, playing games, and receiving broadcasts. is being implemented with Furthermore, recently, an image display device has been implemented as a smart device (eg, a smart television).

Korean Patent Application No. 10-2011-0052965

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image processing apparatus and method capable of reducing a flicker phenomenon of an image display device.

An image processing apparatus according to an embodiment of the present specification outputs a pulse of one frame corresponding to each of a plurality of sub-pixels included in one pixel to each sub-pixel, wherein the plurality of pulses of one frame is output to each sub-pixel. data conversion that converts the plurality of sub-pulses to a sub-pulse of , equalizes the area of the plurality of sub-pulses, converts the pulse amplitudes and pulse widths differently, and outputs the converted plurality of sub-pulses as pulses of one frame to the corresponding pixel It may include more wealth.

As an example related to the present invention, the data conversion unit may change the pulses of the one frame into first to third sub-pulses, and make the first to third sub-pulses the same area as the first to third sub-pulses. Each amplitude of 3 pulses and each pulse width can be converted differently.

As an example related to the present invention, the corresponding pixel may be a light emitting diode (LED).

As an example related to the present invention, the data conversion unit may include each amplitude and each pulse width of the first to third pulses while making the areas of the first to third sub-pulses the same so that the output light amount of the LED is the same. can be converted differently.

An image processing method according to an embodiment of the present specification is an image processing method of outputting a pulse of one frame corresponding to each of a plurality of sub-pixels included in one pixel to each sub-pixel, wherein a plurality of pulses of one frame changing to a sub-pulse of ; converting the pulse amplitudes and pulse widths to be different from each other while making the areas of the plurality of sub-pulses the same; and outputting the converted plurality of sub-pulses as pulses of one frame to a corresponding pixel.

An image processing apparatus and method according to an embodiment of the present invention include converting a pulse of one frame into a plurality of sub-pulses, making the area of the plurality of sub-pulses the same, and converting a pulse amplitude and a pulse width to be different, By outputting the converted plurality of sub-pulses as pulses of one frame to a corresponding pixel, it is possible to reduce a flicker phenomenon of an image display device.

1 is a block diagram showing an image display device and an external input device related to the present invention.
2 is a block diagram illustrating a light emitting diode display to which an image processing apparatus according to an embodiment of the present invention is applied.
3 is an exemplary diagram illustrating flicker (inter flicker) generated when grayscale is expressed in a PWM method.
4 is an exemplary diagram illustrating a pulse signal having the same pulse area.
5 is an exemplary diagram illustrating a pulse of one frame according to an embodiment of the present invention.
6A-6B are other exemplary views illustrating a pulse of one frame according to an embodiment of the present invention.

It should be noted that technical terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. In addition, the technical terms used in this specification should be interpreted in the meaning generally understood by those of ordinary skill in the art to which the present invention belongs, unless otherwise defined in this specification, and excessively inclusive. It should not be construed in the meaning of a human being or in an excessively reduced meaning. In addition, when the technical terms used in the present specification are incorrect technical terms that do not accurately express the spirit of the present invention, they should be understood by being replaced with technical terms that those skilled in the art can correctly understand. In addition, general terms used in the present invention should be interpreted as defined in advance or according to the context before and after, and should not be interpreted in an excessively reduced meaning.

Also, as used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "consisting of" or "comprising" should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps.

Also, terms including ordinal numbers such as first, second, etc. used herein may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the spirit of the present invention, and should not be construed as limiting the spirit of the present invention by the accompanying drawings.

In the present specification, the video display device includes both an apparatus for receiving and displaying a broadcast, recording and reproducing a moving picture, and an apparatus for recording and reproducing audio. Hereinafter, as such an example, a television is demonstrated as an example.

1 is a block diagram showing an image display device 100 and an external input device 200 related to the present invention. The image display device 100 includes a tuner 110 , a demodulator 120 , a signal input/output unit 130 , an interface unit 140 , a control unit 150 , a storage unit 160 , a display unit 170 , and an audio unit. and an output unit 180 . However, the external input device 200 is a device separate from the image display device 100 , but may be included as a component of the image display device 100 .

Referring to FIG. 1 , the tuner 110 selects an RF broadcast signal corresponding to a channel selected by a user from among radio frequency (RF) broadcast signals received through an antenna, and converts the RF broadcast signal to an intermediate frequency signal or a baseband image. /convert to audio signal For example, if the RF broadcast signal is a digital broadcast signal, the tuner 110 converts the RF broadcast signal into a digital IF signal (DIF). On the other hand, if the RF broadcast signal is an analog broadcast signal, the tuner 110 converts the RF broadcast signal into an analog baseband video/audio signal (CVBS/SIF). As such, the tuner 110 may be a hybrid tuner capable of processing a digital broadcast signal and an analog broadcast signal.

The digital IF signal DIF output from the tuner 110 is input to the demodulator 120 , and the analog baseband video/audio signal CVBS/SIF output from the tuner 110 is input to the controller 160 . can The tuner 120 may receive a single-carrier RF broadcast signal according to an Advanced Television Systems Committee (ATSC) method or a multi-carrier RF broadcast signal according to a Digital Video Broadcasting (DVB) method.

Although one tuner 110 is shown in the drawings, the present invention is not limited thereto, and the image display device 100 may include a plurality of tuners, for example, first and second tuners. In this case, the first tuner may receive the first RF broadcast signal corresponding to the broadcast channel selected by the user, and the second tuner may sequentially or periodically receive the second RF broadcast signal corresponding to the pre-stored broadcast channel. . The second tuner may convert the RF broadcast signal into a digital IF signal (DIF) or an analog baseband video/audio signal (CVBS/SIF) in the same manner as the first tuner.

The demodulator 120 receives the digital IF signal DIF converted by the tuner 110 and performs a demodulation operation. For example, if the digital IF signal DIF output from the tuner 110 is ATSC, the demodulator 120 performs 8-Vestigal Side Band (8-VSB) demodulation. In this case, the demodulator 120 may perform channel decoding such as trellis decoding, de-interleaving, and Reed-Solomon decoding. To this end, the demodulator 120 may include a Trellis decoder, a de-interleaver, a Reed Solomon decoder, and the like.

For another example, if the digital IF signal DIF output from the tuner 110 is DVB, the demodulator 120 performs coded orthogonal frequency division modulation (COFDMA) demodulation. In this case, the demodulator 120 may perform channel decoding such as convolutional decoding, deinterleaving, and Reed-Solomon decoding. To this end, the demodulator 120 may include a convolution decoder, a deinterleaver, and a Reed-Solomon decoder.

The signal input/output unit 130 may be connected to an external device to perform signal input and output operations, and to this end, may include an A/V input/output unit and a wireless communication unit.

A/V input/output unit is Ethernet (Ethernet) terminal, USB terminal, CVBS (Composite Video Banking Sync) terminal, component terminal, S-video terminal (analog), DVI (Digital Visual Interface) terminal, HDMI (High Definition Multimedia Interface) terminal , a Mobile High-definition Link (MHL) terminal, an RGB terminal, a D-SUB terminal, an IEEE 1394 terminal, an SPDIF terminal, a Liquid HD terminal, and the like. A digital signal input through these terminals may be transmitted to the controller 150 . In this case, the analog signal input through the CVBS terminal and the S-video terminal may be converted into a digital signal through an analog-to-digital converter (not shown) and transmitted to the controller 150 .

The wireless communication unit may perform wireless Internet access. For example, the wireless communication unit performs wireless Internet access using Wireless LAN (WLAN) (Wi-Fi), Wireless broadband (Wibro), World Interoperability for Microwave Access (Wimax), High Speed Downlink Packet Access (HSDPA), etc. can do. In addition, the wireless communication unit may perform short-range wireless communication with other electronic devices. For example, the wireless communication unit may perform short-range wireless communication using Bluetooth, Radio Frequency Identification (RFID), infrared data association (IrDA), Ultra Wideband (UWB), ZigBee, etc. have.

The signal input/output unit 130 provides a video signal and audio provided from an external device such as a DVD (Digital Versatile Disk) player, a Blu-ray player, a game device, a camcorder, a computer (laptop), a mobile device, a smart phone, etc. Signals and data signals may be transmitted to the controller 150 . In addition, image signals, audio signals, and data signals of various media files stored in an external storage device such as a memory device or a hard disk may be transmitted to the controller 150 . In addition, the image signal, the audio signal, and the data signal processed by the controller 150 may be output to another external device.

The signal input/output unit 130 may be connected to a set-top box, for example, a set-top box for Internet Protocol TV (IPTV), through at least one of the above-described various terminals to perform signal input and output operations. For example, the signal input/output unit 130 may transmit a video signal, an audio signal, and a data signal processed by the IPTV set-top box to the control unit 150 to enable two-way communication, and the signal input/output unit 130 may be processed by the control unit 150 Signals can also be forwarded to a set-top box for IPTV. Here, the IPTV may include ADSL-TV, VDSL-TV, FTTH-TV, etc. classified according to the transmission network.

The digital signal output from the demodulator 120 and the signal output unit 130 may include a stream signal TS. The stream signal TS may be a signal in which an image signal, an audio signal, and a data signal are multiplexed. For example, the stream signal TS may be an MPEG-2 TS (Transprt Stream) in which an MPEG-2 standard video signal, a Dolby AC-3 audio signal, etc. are multiplexed. Here, the MPEG-2 TS may include a header of 4 bytes and a payload of 184 bytes.

The interface unit 140 may receive an input signal for power control, channel selection, screen setting, etc. from the external input device 200 , or transmit a signal processed by the control unit 160 to the external input device 200 . . The interface unit 140 and the external input device 200 may be connected by wire or wirelessly.

As an example of the interface unit 140 , a sensor unit may be provided, and the sensor unit is configured to detect the input signal from a remote controller, for example, a remote controller.

The network interface unit (not shown) provides an interface for connecting the video display device 100 to a wired/wireless network including an Internet network. The network interface unit 230 may include an Ethernet terminal or the like for connection with a wired network, and for connection with a wireless network, WLAN (Wireless LAN) (Wi-Fi), Wibro (Wireless) broadband), World Interoperability for Microwave Access (Wimax), and High Speed Downlink Packet Access (HSDPA) communication standards may be used.

The network interface unit (not shown) may access a predetermined web page through a network. That is, by accessing a predetermined web page through a network, it is possible to transmit or receive data with a corresponding server. In addition, content or data provided by a content provider or network operator may be received. That is, it is possible to receive content such as a movie, advertisement, game, VOD, and broadcast signal and information related thereto provided from the content provider or the network provider through the network. In addition, it is possible to receive firmware update information and an update file provided by a network operator. It may also transmit data to the Internet or to a content provider or network operator.

Also, the network interface unit (not shown) may select and receive a desired application from among applications open to the public through a network.

The controller 150 may control the overall operation of the image display device 100 . More specifically, the controller 150 is configured to control image generation and output. For example, the controller 150 may control the tuner 110 to tune an RF broadcast signal corresponding to a channel selected by the user or a pre-stored channel. Although not shown in the drawings, the controller 150 may include a demultiplexer, an image processor, an audio processor, a data processor, an OSD (On Screen Display) generator, and the like. In addition, the controller 150 may include a CPU or a peripheral device in hardware.

The controller 150 may demultiplex the stream signal TS, for example, the MPEG-2 TS, and separate it into an image signal, an audio signal, and a data signal.

The controller 150 may perform image processing, for example, decoding, on the demultiplexed image signal. In more detail, the control unit 150 decodes a video signal encoded in the MPEG-2 standard using an MPEG-2 decoder, and uses an H.264 decoder to perform an H according to a Digital Multimedia Broadcasting (DMB) scheme or DVB-H. It is possible to decode a video signal encoded in the .264 standard. Also, the controller 150 may process the image to adjust brightness, tint, and color of the image signal. The image signal processed by the control unit 150 may be transmitted to the display unit 170 or may be transmitted to an external output device (not shown) through an external output terminal.

The controller 150 may perform voice processing, eg, decoding, on the demultiplexed voice signal. In more detail, the control unit 150 decodes the encoded audio signal of the MPEG-2 standard using the MPEG-2 decoder, and uses the MPEG 4 decoder of the MPEG 4 BSAC (Bit Sliced Arithmetic Coding) standard according to the DMB method. The coded voice signal is decoded, and the coded voice signal of the AAC (Advanced Audio Codec) standard of MPEG 2 according to the satellite DMB scheme or DVB-H can be decoded using the AAC decoder. In addition, the control unit 150 may process a base (Base), a treble (Treble), volume control, and the like. The audio signal processed by the controller 150 may be transmitted to the audio output unit 180, for example, a speaker, or may be transmitted to an external output device.

The controller 150 may perform signal processing on an analog baseband video/audio signal (CVBS/SIF). Here, the analog baseband video/audio signal (CVBS/SIF) input to the controller 150 may be an analog baseband video/audio signal output from the tuner 110 or the signal input/output unit 130 . The signal-processed image signal is displayed through the display unit 170 , and the signal-processed audio signal is output through the audio output unit 180 .

The controller 150 may perform data processing, eg, decoding, on the demultiplexed data signal. Here, the data signal may include EPG (Electronic Program Guide) information including broadcast information such as start time and end time of a broadcast program aired on each channel. The EPG information may include, for example, ATSC-Program and System Information Protocol (TSC-PSIP) information in the ATSC scheme and DVB-Service Information (DVB-SI) information in the DVB scheme. ATSC-PSIP information or DVB-SI information may be included in a header (4 bytes) of MPEG-2 TS.

The controller 150 may perform a control operation for OSD processing. In more detail, the controller 150 is an OSD for displaying various information in the form of graphics or text based on at least one of an image signal and a data signal or an input signal received from the external input device 200 . signal can be generated. The OSD signal may include various data such as a user interface screen, a menu screen, a widget, and an icon of the image display device 100 .

The storage unit 160 may store a program for signal processing and control of the controller 150 , and may store signal-processed image signals, audio signals, and data signals. The storage unit 160 includes a flash memory, a hard disk, a multimedia card micro type, a card type memory (eg, SD or XD memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk It may include at least one storage medium.

The display unit 170 may generate a driving signal by converting an image signal, a data signal, an OSD signal, etc. processed by the control unit 150 into an RGB signal. Through this, the display unit 170 outputs an image. The display unit 170 includes a plasma display panel (PDP), a liquid crystal display (LCD), a thin film transistor liquid crystal display (TFT-LCD), an organic light emitting diode (OLED) Light Emitting Diode: OLED), flexible display (flexible display), three-dimensional display (3D display), can be implemented in various forms such as an e-ink display (e-ink display). Also, the display 180 may be implemented as a touch screen to perform a function of an input device.

The audio output unit 180 outputs the audio signal processed by the control unit 150, for example, a stereo signal or a 5.1 signal. The audio output unit 180 may be implemented with various types of speakers.

Meanwhile, a photographing unit (not shown) for photographing the user may be further provided. The photographing unit (not shown) may be implemented with one camera, but is not limited thereto, and may be implemented with a plurality of cameras. Image information captured by the photographing unit (not shown) is input to the control unit 270 .

Meanwhile, in order to detect the user's gesture, as described above, a sensing unit (not shown) including at least one of a touch sensor, a voice sensor, a position sensor, and a motion sensor may be further provided in the image display device 100 . have. The signal sensed by the sensing unit (not shown) may be transmitted to the control unit 150 through the user input interface unit 140 .

The controller 150 may detect a user's gesture by individually or in combination with an image captured by a photographing unit (not shown) or a signal sensed from a sensing unit (not shown).

The power supply unit (not shown) supplies the corresponding power throughout the image display device 100 . In particular, to supply power to the control unit 150 that can be implemented in the form of a system on chip (SOC), the display unit 170 for image display, and the audio output unit 180 for audio output. can

To this end, the power supply unit (not shown) may include a converter (not shown) for converting AC power into DC power. On the other hand, for example, when the display unit 170 is implemented as a liquid crystal panel having a plurality of backlight lamps, an inverter (not shown) capable of PWM operation may be further provided for luminance variable or dimming driving. may be

The external input device 200 is connected to the interface unit 140 by wire or wirelessly, and transmits an input signal generated according to a user input to the interface unit 140 . The external input device 200 may include a remote controller, a mouse, a keyboard, and the like. The remote controller may transmit an input signal to the interface unit 140 through Bluetooth, RF communication, infrared communication, Ultra Wideband (UWB), ZigBee, or the like. The remote controller may be implemented as a spatial remote control device. The space remote control device may generate an input signal by sensing the motion of the main body in space.

The video display device 100 receives at least one of ATSC method (8-VSB method) digital broadcast, DVB-T method (COFDM method) digital broadcast, ISDB-T method (BST-OFDM method) digital broadcast, etc. It can be implemented as a possible fixed digital broadcast receiver. In addition, the image display device 100 is a digital broadcast of the terrestrial DMB method, the digital broadcast of the satellite DMB method, the digital broadcast of the ATSC-M/H method, the digital broadcast of the DVB-H method (COFDM method), and the media flow (Media Forward). Link Only) type digital broadcasting, etc. may be implemented as a mobile digital broadcasting receiver capable of receiving at least one. In addition, the image display device 100 may be implemented as a digital broadcast receiver for cable, satellite communication, and IPTV.

Also, the video display device described above may be applied to a mobile terminal. The mobile terminal includes a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, a tablet PC ( tablet PC), ultrabooks, and the like.

When the video display device is used as a mobile terminal, a wireless communication unit may be added.

The wireless communication unit may include one or more modules that enable wireless communication between the mobile terminal 100 and a wireless communication system or between the mobile terminal and a network in which the mobile terminal is located. For example, the wireless communication unit may include at least one of a broadcast reception module, a mobile communication module, a wireless Internet module, a short-range communication module, and a location information module.

The broadcast reception module receives a broadcast signal and/or broadcast related information from an external broadcast management server through a broadcast channel.

The broadcast channel may include a satellite channel and a terrestrial channel. The broadcast management server may mean a server that generates and transmits a broadcast signal and/or broadcast-related information or a server that receives and transmits a previously generated broadcast signal and/or broadcast-related information to a terminal. The broadcast signal may include a TV broadcast signal, a radio broadcast signal, and a data broadcast signal, as well as a TV broadcast signal or a broadcast signal in which a data broadcast signal is combined with a radio broadcast signal.

The broadcast related information may mean information related to a broadcast channel, a broadcast program, or a broadcast service provider. The broadcast-related information may be provided through a mobile communication network. In this case, it may be received by the mobile communication module 112 .

The broadcast-related information may exist in various forms. For example, it may exist in the form of an Electronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB) or an Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld (DVB-H).

The broadcast reception module, for example, DMB-T (Digital Multimedia Broadcasting-Terrestrial), DMB-S (Digital Multimedia Broadcasting-Satellite), MediaFLO (Media Forward Link Only), DVB-H (Digital Video Broadcast-Handheld) , a digital broadcast signal may be received using a digital broadcast system such as Integrated Services Digital Broadcast-Terrestrial (ISDB-T). Of course, the broadcast reception module may be configured to be suitable for other broadcast systems as well as the aforementioned digital broadcast system.

A broadcast signal and/or broadcast-related information received through the broadcast reception module may be stored in a memory.

The mobile communication module transmits/receives wireless signals to and from at least one of a base station, an external terminal, and a server on a mobile communication network. The wireless signal may include various types of data according to transmission/reception of a voice call signal, a video call signal, or a text/multimedia message.

The mobile communication module is configured to implement a video call mode and a voice call mode. The video call mode refers to a state in which a call is made while viewing the video of the other party, and the voice call mode refers to a state in which a call is made without viewing the video of the other party. In order to implement the video call mode and the voice call mode, the mobile communication module is configured to transmit/receive at least one of voice and video.

The wireless Internet module refers to a module for wireless Internet access, and may be built-in or external to the mobile terminal 100 . Wireless Internet technologies include WLAN (Wireless LAN), WiFi (Wireless Fidelity) Direct, DLNA (Digital Living Network Alliance), Wibro (Wireless broadband), Wimax (World Interoperability for Microwave Access), HSDPA (High Speed Downlink Packet Access), etc. This can be used.

The short-distance communication module refers to a module for short-distance communication. Short range communication technologies such as Bluetooth™, Radio Frequency Identification (RFID), Infrared Data Association (IrDA), Ultra Wideband (UWB), ZigBee, Near Field Communication (NFC), Wi-Fi Direct or the like may be used.

The location information module is a module for acquiring a location of a mobile terminal, and a representative example thereof includes a Global Position System (GPS) module or a Wireless Fidelity (WiFi) module.

On the other hand, when the display unit and the sensor for sensing a touch operation (hereinafter, referred to as a 'touch sensor') form a layer structure (hereinafter referred to as a 'touch screen'), the display unit may be used as an input device in addition to the output device can The touch sensor may have the form of, for example, a touch film, a touch sheet, a touch pad, or the like.

The touch sensor may be configured to convert a change in pressure applied to a specific part of the display unit or capacitance generated in a specific part of the display unit into an electrical input signal. The touch sensor may be configured to detect not only the position and area where the touch object is touched on the touch sensor, but also the pressure at the time of the touch. Here, the touch object is an object that applies a touch to the touch sensor, and may be, for example, a finger, a touch pen or a stylus pen, a pointer, or the like.

When there is a touch input to the touch sensor, a signal(s) corresponding thereto is sent to the touch controller. The touch controller processes the signal(s) and then sends the corresponding data to the controller. Accordingly, the control unit can know which area of the display unit has been touched, and the like.

Hereinafter, a case in which the display unit 170 is a light emitting diode (OLED) display device will be described with reference to FIGS. 1 and 2 .

2 is a block diagram illustrating a light emitting diode display to which an image processing apparatus according to an embodiment of the present invention is applied.

As shown in FIG. 2 , the LED display device according to an embodiment of the present invention includes an image processing unit 210 , a timing control unit 220 , a data driving unit 230 , a scan driving unit 240 , and a display panel 250 . do.

The image processing unit 210 receives a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, a clock signal, and red, green, and blue signals RGB (hereinafter referred to as RGB) from the outside. The image processing unit 210 converts the RGB signals RGB into red, green, blue, and white signals RGBW (hereinafter referred to as RGBW) and outputs the converted RGB signals to the timing control unit 220 . The image processing unit 210 varies the gamma voltage to realize the peak luminance according to the average image level by using the RGB signal (RGB) included in one frame data supplied from the outside. The image processing unit 210 variously processes frame data received from the outside, and a detailed description thereof will be omitted since it is a known technique.

The timing controller 220 receives a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, a clock signal, and an RGBW signal RGBW from the image processing unit 210 .

The timing controller 220 controls the operation timings of the data driver 230 and the scan driver 240 using timing signals such as a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, and a clock signal. Since the timing controller 220 may determine the frame period by counting the data enable signal of one horizontal period, the vertical synchronization signal and the horizontal synchronization signal supplied from the outside may be omitted. The control signals generated by the timing controller 220 include a gate timing control signal GDC for controlling the operation timing of the scan driver 240 and a data timing control signal DDC for controlling the operation timing of the data driver 230 . ) is included. The gate timing control signal GDC includes a gate start pulse, a gate shift clock, and a gate output enable signal. The data timing control signal DDC includes a source start pulse, a source sampling clock, and a source output enable signal.

The data driver 230 samples and latches the RGBW signal RGBW supplied from the timing controller 220 in response to the data timing control signal DDC received from the timing controller 220 to convert it into data of a parallel data system. . When converting the data of the parallel data system, the data driver 230 converts the RGBW signal RGBW into digital data according to the gamma voltage into analog data. In this case, the digital data to analog data is converted by a digital to analog converter (DAC) included in the data driver 230 . The data driver 230 supplies the converted image signal DATA through the data lines DL1 to DLn to the sub-pixels SPr, SPg, SPb, and SPw included in the display panel 150 .

The scan driver 240 enables transistors of the sub-pixels SPr, SPg, SPb, and SPw included in the display panel 250 to operate in response to the gate timing control signal GDC supplied from the timing controller 220 . The scan signal is sequentially generated while shifting the signal level with the swing width of the gate driving voltage. The scan driver 240 supplies the scan signal generated through the scan lines SL1 to SLm to the sub-pixels SPr, SPg, SPb, and SPw included in the display panel 250 .

The display panel 250 is formed of an organic light emitting display panel including sub-pixels SPr, SPg, SPb, and SPw arranged in a matrix form. The sub-pixels SPr, SPg, SPb, and SPw include a red sub-pixel SPr, a green sub-pixel SPg, a blue sub-pixel SPb, and a white sub-pixel SPw, which are one pixel (P). becomes this

In general, in order to drive an LED array as a display, a PM (Passive Matrix) method and an AM (Active Matrix) method are used. In the AM method, the light is maintained by memorizing the values of each pixel until the end of one frame, but in the PM method, the light is quickly turned on in line units and a visual afterimage effect (lasting about 1/10 second) is used to create one image. make it look like If a low frame rate is applied, the visual afterimage effect is weakened and the off line becomes visible, increasing the probability of occurrence of flicker. This flicker that occurs within one frame is called "Intra Flicker".

In addition, the light intensity of the LED is adjusted to express the image grayscale. For this purpose, a PAM (Pulse Amplitude Modulation) method and a PWM (Pulse Width Modulation) method or a mixture of PAM and PWM is used. However, the PWM method turns on only the narrow pulse section as it goes to the lower gray scale, which causes the black section to become longer, which causes the flicker (Inter Flicker) to exceed the time that the afterimage of the eye is maintained between frames. , which will be described with reference to FIG. 3 .

3 is an exemplary diagram illustrating flicker (inter flicker) generated when grayscale is expressed in a PWM method.

As shown in FIG. 3, the PWM method turns on only the narrow pulse section toward the lower gray scale, so that the black section becomes longer and the afterimage of the eye is maintained between frames. Flickr (Inter Flicker) is created out of time.

If the frequency is simply increased to reduce the flicker phenomenon, the turn-off period remains the same, so the flicker phenomenon is not significantly improved. In order to solve this problem, one data (one frame) is expressed by expressing n different signals that can emit the same amount of light and repeating it several times. The reason this is possible is that the LED emits the same amount of light even if the current magnitude and pulse width are different if the area of the turn-on section created by the magnitude (current value) and the pulse width is the same as shown in FIG. because it can

4 is an exemplary diagram illustrating a pulse signal having the same pulse area.

As shown in FIG. 4 , in the LED, even if the first and second pulses have different current magnitudes (current values, amplitudes) and pulse widths, if the areas of the first and second pulses are the same, the same amount of light is emitted. to output For example, when it is assumed that the current value (height) of the first pulse is 2I, the width of the first pulse is 1P, the current value (height) of the second pulse is 1I, and the width of the second pulse is 2P , The current value (height) and pulse width of the first and second pulses are different from each other, but the pulse area is the same, so that the same amount of light is output.

5 is an exemplary diagram illustrating a pulse of one frame according to an embodiment of the present invention.

As shown in FIG. 5 , in the image processing apparatus outputting a pulse of one frame corresponding to each of a plurality of sub-pixels included in one pixel to each sub-pixel, the image processing unit 210 is configured to: to change the pulses of , into a plurality of sub-pulses, convert the height and width of the plurality of sub-pulses to be the same while maintaining the same area, and output the converted plurality of sub-pulses as pulses of one frame to the corresponding pixel It may further include a data conversion unit (not shown).

For example, the image processing unit 210 converts the pulses of one frame into first to third sub-pulses (Frame 1/3, Frame 2/3, and Frame 3/3), and changes the first to third sub-pulses (Frame 1/3, Frame 2/3, Frame 3/3). The area (pulse amplitude * pulse width) of the sub-pulses is the same, but the height and width are converted to be different from each other, and the converted first to third sub-pulses are output to the corresponding pixel as pulses of one frame. Assuming that the image processing unit 210 sets the amplitude of the first sub-pulse to 3 times, the amplitude of the second sub-pulse to 2 times, and the amplitude of the third sub-pulse to 1 time, The width of the first sub-pulse is changed by one time, the width of the second sub-pulse by 1.5 times, and the width of the third sub-pulse by three times so that the area is the same. That is, the image processing unit 210 multiplies the frequency n times and combines each pixel value (gray level) with current values (amplitudes) of different magnitudes and pulses of different widths to output the same n different signals. is divided into n frames and output. Accordingly, n frames always have short duty, medium duty, and long duty, thereby reducing flicker that may have occurred in the conventional short pulse.

Also, the order of the sub-pulses may be variously changed as shown in FIGS. 6A-6B .

6A-6B are other exemplary views illustrating a pulse of one frame according to an embodiment of the present invention.

As shown in FIG. 6A , the image processing unit 210 converts the pulses of one frame into first to third sub-pulses (Frame 1/3, Frame 2/3, Frame 3/3), and The area (pulse amplitude * pulse width) of the first to third sub-pulses is the same, the height and width are converted to be different from each other, and the converted first to third sub-pulses are output to the corresponding pixel as the pulses of the one frame . For example, assuming that the image processing unit 210 sets the amplitude of the first sub-pulse to be 1, the amplitude of the second sub-pulse is doubled, and the amplitude of the third sub-pulse is set to 3 times, the first to The width of the first sub-pulse is changed by three times, the width of the second sub-pulse by 1.5 times, and the width of the third sub-pulse by one time so that the area of the third pulse is the same.

6B, assuming that the image processing unit 210 sets the amplitude of the first sub-pulse to 1, the amplitude of the third sub-pulse to 3 times, and the amplitude of the third sub-pulse to 2 times, The width of the first sub-pulse is changed by 3 times, the width of the second sub-pulse by 1 time, and the width of the third sub-pulse is changed by 1.5 times so that the areas of the first to third pulses are the same.

Here, the lower the "Gray Level", the more difficult it is to lower the current and increase the pulse, so the basic current size can be set to be n times higher than the lowest "Gray Level", where n may be the number of frames to be allocated.

Those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

210: image processing unit

Claims (5)

An image processing apparatus for outputting a pulse of one frame corresponding to each of a plurality of sub-pixels included in one pixel to each sub-pixel, the image processing apparatus comprising:
The pulses of the one frame are changed into a plurality of sub-pulses, the area of the plurality of sub-pulses is the same, the pulse amplitude and the pulse width are different from each other, and the converted plurality of sub-pulses are converted to the pulses of the one frame. It further includes a data conversion unit to output to the pixel,
The one frame is divided into sub-frames corresponding to the plurality of changed sub-pulses, and each sub-frame has a different duty cycle. According to claim 1, wherein the data conversion unit,
The pulses of the one frame are changed to first to third sub-pulses, and the respective amplitudes and the respective pulse widths of the first to third pulses are converted to be different while the respective areas of the first to third sub-pulses are the same. An image processing apparatus, characterized in that. The image processing apparatus according to claim 2, wherein the corresponding pixel is a light emitting diode (LED). The method of claim 3, wherein the data conversion unit,
The image processing apparatus according to claim 1, wherein the respective amplitudes and the respective pulse widths of the first to third pulses are converted to be different from each other while making the respective areas of the first to third sub-pulses the same so that the output light amount of the LED is the same. An image processing method of outputting a pulse of one frame corresponding to each of a plurality of sub-pixels included in one pixel to each sub-pixel, the image processing method comprising:
changing the pulses of the one frame into a plurality of sub-pulses;
converting pulse amplitudes and pulse widths to be different from each other while making the areas of the plurality of sub-pulses the same;
and outputting the converted plurality of sub-pulses as pulses of one frame to a corresponding pixel,
The one frame is divided into sub-frames corresponding to the plurality of changed sub-pulses, and each sub-frame has a different duty cycle.

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