KR102252578B1 - Image display apparatus - Google Patents

Abstract

The present invention relates to an image display device. An image display device according to an embodiment of the present invention includes a panel, a plurality of backlight lamps that output light to the panel, a power supply unit that outputs a common voltage to the plurality of backlights, and a plurality of backlight lamps using a common voltage. And a lamp driving unit for driving the lamp and a driving control unit for controlling the lamp driving unit, and the lamp driving unit includes a plurality of switching elements for switching the plurality of backlight lamps, and the driving control unit includes voltages of each drain terminal of the plurality of switching elements And a processor for generating a switching control signal for driving each gate terminal of the plurality of switching elements, and the processor varies a level of the switching control signal based on the magnitude of the drain terminal voltage. Accordingly, it is possible to reduce heat generation of a plurality of switching elements for switching a plurality of backlight lamps.

Description

Image display apparatus

The present invention relates to an image display device, and more particularly, to an image display device capable of reducing power consumption when driving a backlight.

Digital broadcasting refers to broadcasting that transmits digital video and audio signals. Compared to analog broadcasting, digital broadcasting is more resistant to external noise, so data loss is small, it is advantageous for error correction, has high resolution, and provides a clear screen. In addition, digital broadcasting enables interactive services unlike analog broadcasting.

Meanwhile, in response to a user's request to view a clear screen, the resolution of an image display device is increasing, and accordingly, an image display device with an increased resolution is being developed. In this case, as the resolution increases, power consumption in the image display device increases.

An object of the present invention is to provide an image display device capable of reducing heat generation of a plurality of switching elements for switching a plurality of backlight lamps.

An image display device according to an embodiment of the present invention for achieving the above object uses a panel, a plurality of backlight lamps that output light to the panel, a power supply unit that outputs a common voltage to the plurality of backlights, and a common voltage. Thus, a lamp driving unit for driving a plurality of backlight lamps, and a driving control unit for controlling the lamp driving unit, the lamp driving unit includes a plurality of switching elements for switching the plurality of backlight lamps, and the driving control unit includes a plurality of switching devices. And a processor for generating a switching control signal for driving each gate terminal of the plurality of switching elements based on the voltage of each drain terminal of the device, wherein the processor includes a level of the switching control signal based on the magnitude of the drain terminal voltage Is variable.

In addition, an image display device according to an embodiment of the present invention for achieving the above object includes a panel, a plurality of backlight lamps that output light to the panel and are connected in parallel with each other, and a power supply unit that outputs a common voltage to the plurality of backlights. And, a lamp driving unit for driving a plurality of backlight lamps, and a driving control unit for controlling the lamp driving unit, and the lamp driving unit includes a plurality of switching elements for switching the plurality of backlight lamps, and the driving control unit includes a plurality of A switching control signal for driving each gate terminal of the plurality of switching elements is generated based on the lowest drain terminal voltage among the voltages of each drain terminal of the switching element, but according to the difference between the lowest drain terminal voltage and each drain terminal voltage. And a processor for varying the level and duty of the switching control signal.

According to an embodiment of the present invention, an image display device includes a panel, a plurality of backlight lamps for outputting light to the panel, a power supply for outputting a common voltage to the plurality of backlights, and a plurality of backlights using a common voltage. A lamp driving unit for driving the lamp and a driving control unit for controlling the lamp driving unit, and the lamp driving unit includes a plurality of switching elements for switching a plurality of backlight lamps, and the driving control unit includes each drain terminal of the plurality of switching elements A processor for generating a switching control signal for driving each gate terminal of the plurality of switching elements based on the voltage, the processor, by varying the level of the switching control signal based on the magnitude of the drain terminal voltage, the plurality of It is possible to reduce heat generation of a plurality of switching elements for switching the backlight lamp of.

In particular, for driving a high-resolution panel, the current flowing through the switching element increases, and accordingly, the element stress of the switching element increases, but the level of the switching control signal is adjusted based on the magnitude of the drain terminal voltage of the plurality of switching elements. By varying, the element stress of the switching element is reduced.

In particular, by varying the level and duty of the switching control signal based on the magnitude of the drain terminal voltage of the switching element, it is possible to reduce heat generation and power consumption of the plurality of switching elements.

On the other hand, when only some of the plurality of backlight lamps are operated by local dimming, based on the lowest drain terminal voltage among the drain terminal voltages of the switching elements corresponding to the plurality of lamps operating among the plurality of backlight lamps. , By generating target driving currents flowing through a plurality of lamps operating among the plurality of backlight lamps, and outputting a switching control signal corresponding to the generated target driving current, it is possible to reduce power consumption even during local dimming driving.

Meanwhile, since heat generation of the switching element is reduced, the size of the heat sink can be reduced, and the sizes of the lamp driver and the circuit board of the driving control unit can be reduced.

On the other hand, the processor compensates the level of the switching control signal based on the temperature around the plurality of backlight lamps, thereby stably driving the backlight lamp according to the ambient temperature, reducing heat generation of the switching element, and reducing power consumption. You can do it.

1 is a diagram showing an image display system according to an embodiment of the present invention.
2 is an internal block diagram of an image display device according to an embodiment of the present invention.
3 is an internal block diagram of the control unit of FIG. 2.
4 is a diagram illustrating a control method of the remote control device of FIG. 2.
5 is an internal block diagram of the remote control device of FIG. 2.
6 is a diagram illustrating an example of an interior of the power supply unit and the display of FIG. 2.
7A to 7D are diagrams illustrating various examples of an arrangement of the backlight lamp of FIG. 6.
8 is an example of a partial circuit diagram of an image display device according to an embodiment of the present invention.
9 to 12 are views referenced for explanation of the circuit diagram of FIG. 8.
13 is another example of a partial circuit diagram of an image display device according to an embodiment of the present invention.
14 is a diagram referred to for explanation of the circuit diagram of FIG. 13.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The suffixes "module" and "unit" for the constituent elements used in the following description are given in consideration of only the ease of writing in the present specification, and do not impart a particularly important meaning or role by themselves. Therefore, the "module" and "unit" may be used interchangeably with each other.

1 is a view showing the appearance of an image display device according to an embodiment of the present invention.

Referring to FIG. 1, an image display apparatus 100 according to an embodiment of the present invention includes a display (180 in FIG. 2), a control unit for displaying an image on the display (170 in FIG. 2), and power to the display. It may be provided with a power supply unit (190 in Fig. 2) and the like for supplying.

On the other hand, in the trend that the resolution of the image display device 100 increases to HD (High Definition), Full HD, UHD (Ultra High Definition), etc., the power consumption of the image display device 100 increases, and accordingly, Various techniques are being studied to reduce power consumption.

In particular, in an embodiment of the present invention, a technique for reducing heat generation of a plurality of switching elements for switching a plurality of backlight lamps is described.

Meanwhile, when the display 180 includes a liquid crystal panel, a separate backlight lamp is used.

At this time, about 60 to 70% of the power consumption of the image display device 100 is consumed by the backlight lamp or a circuit element driving the backlight lamp. In particular, as the resolution of the image display device 100 increases to HD (High Definition), Full HD, UHD (Ultra High Definition), 4K, 8K, etc., the LED driving voltage (Vf) in the backlight lamp or driving flowing through the LED At least one of the currents If increases.

As the LED driving voltage Vf or the like in the backlight lamp increases, the level of the common voltage commonly applied to the plurality of backlights increases. In this situation, as the level of current flowing through the switching elements driving the plurality of backlight lamps increases, power consumption consumed by the switching elements increases, and heat generation increases.

Accordingly, in the present invention, a technique for reducing heat generation of a plurality of switching elements for switching a plurality of backlight lamps when driving a backlight lamp is described.

Specifically, the image display device 100 outputs light to a panel (210 in FIG. 6) and outputs a plurality of backlight lamps (1140 in FIG. 8) connected in parallel to each other, and a common voltage (VLED) to a plurality of backlights. A lamp driver (256 in FIG. 8) and a lamp driver (256 in FIG. 8) that drive a plurality of backlight lamps (1140 in FIG. 8) using a power supply (190 in FIG. 8) and a common voltage (VLED). ) To control the driving control unit (1120 in Fig. 8), and the driving control unit (120 in Fig. 8) is configured to drive each gate terminal of the plurality of switching elements based on the voltage of each drain terminal of the plurality of switching elements. A switching control signal is generated for, but the level of the switching control signal is varied based on the magnitude of the drain terminal voltage.

In particular, the driving control unit (120 in FIG. 8) may control the level of the switching control signal to increase as the magnitude of the drain terminal voltage increases, particularly, as the difference between the lowest drain terminal voltage and each drain terminal voltage increases. In addition, it is possible to control the duty of the switching control signal to decrease.

Accordingly, power consumption consumed by each switching element is reduced, and consequently, heat generation of the switching element is reduced.

In particular, for driving a high-resolution panel, the current flowing through the switching element increases, and accordingly, the element stress of the switching element increases, but based on the voltage of each drain terminal of the plurality of switching elements, each gate of the plurality of switching elements By controlling the level of the switching control signal for driving the terminal to increase and driving the switching element based on the generated switching control signal, element stress of the switching element is reduced.

On the other hand, when only some of the plurality of backlight lamps are operated by local dimming, based on the lowest drain terminal voltage among the drain terminal voltages of the switching elements corresponding to the plurality of lamps operating among the plurality of backlight lamps. , By generating target driving currents flowing through a plurality of lamps operating among the plurality of backlight lamps, and outputting a switching control signal corresponding to the generated target driving current, it is possible to reduce power consumption even during local dimming driving.

On the other hand, since heat generation of the switching element is reduced, the size of the heat sink can be reduced, and the size of the circuit board (256 in FIG. 8) and the circuit board of the driving controller (120 in FIG. 8) can be reduced.

On the other hand, the driving control unit (1120 in FIG. 8) compensates for the level of the switching control signal based on the temperature around the plurality of backlight lamps, thereby stably driving the backlight lamp according to the ambient temperature, while preventing heat generation of the switching element. While reducing, power consumption can be reduced.

A technique for reducing heat generation of a plurality of switching elements for switching a plurality of backlight lamps when driving the backlight of the image display device described above will be described in more detail with reference to FIG. 8.

2 is an internal block diagram of an image display device according to an embodiment of the present invention.

Referring to FIG. 2, an image display device 100 according to an embodiment of the present invention includes a broadcast receiving unit 105, an external device interface unit 130, a storage unit 140, a user input interface unit 150, and A sensor unit (not shown), a control unit 170, a display 180, and an audio output unit 185 may be included.

The broadcast reception unit 105 may include a tuner unit 110, a demodulation unit 120, and a network interface unit 130. Of course, if necessary, it is possible to design the tuner unit 110 and the demodulation unit 120 so as not to include the network interface unit 130, and on the contrary, while having the network interface unit 130, the tuner unit 110 ) And the demodulation unit 120 may be designed not to be included.

Meanwhile, unlike the drawing, the broadcast receiving unit 105 may include an external device interface unit (135 in FIG. 2). For example, a broadcast signal from the set-top box 250 of FIG. 1 may be received through an external device interface unit (135 of FIG. 2).

The tuner 110 selects a channel selected by a user from among radio frequency (RF) broadcast signals received through the antenna 50 or an RF broadcast signal corresponding to all pre-stored channels. In addition, the selected RF broadcast signal is converted into an intermediate frequency signal or a baseband video or audio signal.

For example, if the selected RF broadcast signal is a digital broadcast signal, it is converted to a digital IF signal (DIF), and if the selected RF broadcast signal is an analog broadcast signal, it is converted to an analog baseband video or audio signal (CVBS/SIF). That is, the tuner unit 110 may process a digital broadcast signal or an analog broadcast signal. The analog baseband video or audio signal (CVBS/SIF) output from the tuner 110 may be directly input to the controller 170.

Meanwhile, the tuner unit 110 sequentially selects RF broadcast signals of all broadcast channels stored through a channel memory function among RF broadcast signals received through an antenna in the present invention, and converts them to an intermediate frequency signal or a baseband video or audio signal. Can be converted to

Meanwhile, the tuner unit 110 may include a plurality of tuners in order to receive broadcast signals of a plurality of channels. Alternatively, a single tuner that simultaneously receives broadcast signals of multiple channels is also possible.

The demodulation unit 120 receives the digital IF signal DIF converted by the tuner unit 110 and performs a demodulation operation.

The demodulator 120 may output a stream signal TS after performing demodulation and channel decoding. In this case, the stream signal may be a signal in which a video signal, an audio signal, or a data signal is multiplexed.

The stream signal output from the demodulator 120 may be input to the controller 170. After performing demultiplexing, video/audio signal processing, and the like, the controller 170 outputs an image to the display 180 and outputs an audio to the audio output unit 185.

The external device interface unit 130 may transmit or receive data with the connected external device 190. To this end, the external device interface unit 130 may include an A/V input/output unit (not shown) or a wireless communication unit (not shown).

The external device interface unit 130 may be connected to an external device such as a digital versatile disk (DVD), a Blu ray, a game device, a camera, a camcorder, a computer (laptop), a set-top box, etc. by wire or wirelessly. , It is also possible to perform input/output operations with external devices.

The A/V input/output unit may receive video and audio signals from an external device. Meanwhile, the wireless communication unit may perform short-range wireless communication with another electronic device.

The network interface unit 135 provides an interface for connecting the image display device 100 to a wired/wireless network including an Internet network. For example, the network interface unit 135 may receive content or data provided by the Internet or a content provider or a network operator through a network.

The storage unit 140 may store a program for processing and controlling each signal in the control unit 170, or may store a signal-processed video, audio, or data signal.

In addition, the storage unit 140 may perform a function for temporary storage of a video, audio, or data signal input to the external device interface unit 130. In addition, the storage unit 140 may store information on a predetermined broadcast channel through a channel storage function such as a channel map.

2 illustrates an embodiment in which the storage unit 140 is provided separately from the control unit 170, but the scope of the present invention is not limited thereto. The storage unit 140 may be included in the control unit 170.

The user input interface unit 150 transmits a signal input by the user to the controller 170 or transmits a signal from the controller 170 to the user.

For example, the remote control device 200 transmits/receives user input signals such as power on/off, channel selection, and screen setting, or local keys such as power keys, channel keys, volume keys, and set values (not shown). A user input signal input from the controller 170 is transmitted to the controller 170, or a user input signal input from a sensor unit (not shown) that senses a user's gesture is transmitted to the controller 170, or a signal from the controller 170 is transmitted. It can be transmitted to the sensor unit (not shown).

The control unit 170, through the tuner unit 110, the demodulation unit 120, or the external device interface unit 130, demultiplexes the input stream or processes the demultiplexed signals to output video or audio. It can generate and output signals.

The image signal processed by the controller 170 may be input to the display 180 and may be displayed as an image corresponding to the corresponding image signal. In addition, the image signal processed by the controller 170 may be input to an external output device through the external device interface unit 130.

The audio signal processed by the control unit 170 may be sound output to the audio output unit 185. In addition, the voice signal processed by the control unit 170 may be input to an external output device through the external device interface unit 130.

Although not shown in FIG. 2, the control unit 170 may include a demultiplexer, an image processing unit, and the like. This will be described later with reference to FIG. 3.

In addition, the controller 170 may control the overall operation of the image display device 100. For example, the control unit 170 may control the tuner unit 110 to select (Tuning) a channel selected by the user or an RF broadcast corresponding to a pre-stored channel.

In addition, the control unit 170 may control the image display apparatus 100 according to a user command or an internal program input through the user input interface unit 150.

Meanwhile, the controller 170 may control the display 180 to display an image. In this case, the image displayed on the display 180 may be a still image or a moving image, and may be a 2D image or a 3D image.

Meanwhile, the controller 170 may generate and display a predetermined 2D object as a 3D object among the images displayed on the display 180. For example, the object may be at least one of a connected web screen (newspaper, magazine, etc.), EPG (Electronic Program Guide), various menus, widgets, icons, still images, moving pictures, and text.

Such a 3D object may be processed to have a depth different from that of an image displayed on the display 180. Preferably, the 3D object may be processed to protrude compared to the image displayed on the display 180.

Meanwhile, the controller 170 may recognize a user's location based on an image captured by a photographing unit (not shown). For example, a distance (z-axis coordinate) between the user and the image display device 100 may be determined. In addition, x-axis coordinates and y-axis coordinates in the display 180 corresponding to the user's location may be identified.

Meanwhile, although not shown in the drawing, a channel browsing processing unit for generating a thumbnail image corresponding to a channel signal or an external input signal may be further provided. The channel browsing processing unit receives the stream signal TS output from the demodulation unit 120 or the stream signal output from the external device interface unit 130, and extracts an image from the input stream signal to generate a thumbnail image. I can. The generated thumbnail image may be stream-decoded together with the decoded image and the like and input to the controller 170. The controller 170 may display a thumbnail list including a plurality of thumbnail images on the display 180 by using the input thumbnail images.

In this case, the thumbnail list may be displayed in a simple view method displayed in a partial area while a predetermined image is displayed on the display 180 or may be displayed in a full view method displayed in most areas of the display 180. The thumbnail images in the thumbnail list may be sequentially updated.

The display 180 converts an image signal, a data signal, an OSD signal, a control signal processed by the controller 170, or an image signal, a data signal, and a control signal received from the external device interface unit 130 to convert a driving signal. Generate.

The display 180 may be a PDP, an LCD, an OLED, a flexible display, or the like, and may also be a 3D display.

In order to view such a 3D image, the display 180 may be divided into an additional display method and a single display method.

The single display method is one that can implement a 3D image by itself without a separate additional display, for example, glasses, etc., for example, a lenticular method, a parallax barrier, etc. Various methods can be applied.

Meanwhile, as an additional display method, a 3D image can be implemented by using an additional display as a viewing device (not shown) in addition to the display 180. For example, various methods such as a head mounted display (HMD) type and a glasses type are used. Can be applied.

Meanwhile, the glasses type may be further divided into a passive method such as a polarizing glasses type and an active method such as a shutter glass type. In addition, the head mounted display type can be divided into a passive type and an active type.

Meanwhile, the viewing device (not shown) may be a 3D glass capable of viewing a stereoscopic image. The 3D glass (not shown) may include a passive type polarizing glass or an active type shutter glass, and may be a concept including the above-described head mount type.

Meanwhile, the display 180 may be configured as a touch screen and used as an input device other than an output device.

The audio output unit 185 receives a signal processed by the control unit 170 and outputs it as a voice.

The photographing unit (not shown) photographs the user. 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. Meanwhile, the photographing unit (not shown) may be buried in the image display apparatus 100 on the display 180 or may be separately disposed. Image information captured by the photographing unit (not shown) may be input to the control unit 170.

The controller 170 may detect a user's gesture based on an image captured from a photographing unit (not shown) or a signal sensed from a sensor unit (not shown), or a combination thereof.

The power supply unit 190 supplies corresponding power throughout the image display device 100. In particular, power can be supplied to the control unit 170 that can be implemented in the form of a System On Chip (SOC), the display 180 for displaying an image, and the audio output unit 185 for outputting audio. have.

Specifically, the power supply unit 190 may include a converter that converts AC power to DC power and a dc/dc converter that converts the level of the DC power.

The remote control device 200 transmits a user input to the user input interface unit 150. To this end, the remote control device 200 may use Bluetooth, Radio Frequency (RF) communication, infrared (IR) communication, Ultra Wideband (UWB), ZigBee, or the like. In addition, the remote control device 200 may receive an image, audio, or data signal output from the user input interface unit 150, and display or output an audio signal on the remote control device 200.

Meanwhile, the above-described image display device 100 may be a digital broadcast receiver capable of receiving a fixed or mobile digital broadcast.

Meanwhile, a block diagram of the image display device 100 shown in FIG. 2 is a block diagram for an embodiment of the present invention. Each component of the block diagram may be integrated, added, or omitted according to the specifications of the image display device 100 that is actually implemented. That is, if necessary, two or more components may be combined into one component, or one component may be subdivided into two or more components to be configured. In addition, functions performed by each block are for explaining the embodiments of the present invention, and specific operations or devices thereof do not limit the scope of the present invention.

On the other hand, the image display device 100 does not include the tuner unit 110 and the demodulation unit 120 shown in Fig. 2, unlike shown in Fig. 2, but the network interface unit 130 or the external device interface unit ( 130), the video content may be received and played back.

Meanwhile, the image display device 100 is an example of an image signal processing device that performs signal processing of an image stored in the device or an input image. Another example of the image signal processing device is the display 180 shown in FIG. 2. A set-top box excluding the and audio output unit 185, the above-described DVD player, Blu-ray player, game device, computer, etc. may be further illustrated.

3 is an internal block diagram of the control unit of FIG. 2.

Referring to the drawings, the control unit 170 according to an embodiment of the present invention includes a demultiplexing unit 310, an image processing unit 320, a processor 330, an OSD generating unit 340, and a mixer 345. , A frame rate converter 350, and a formatter 360. In addition, an audio processing unit (not shown) and a data processing unit (not shown) may be further included.

The demultiplexer 310 demultiplexes an input stream. For example, when an MPEG-2 TS is input, it can be demultiplexed and separated into video, audio, and data signals, respectively. Here, the stream signal input to the demultiplexer 310 may be a stream signal output from the tuner unit 110 or the demodulation unit 120 or the external device interface unit 130.

The image processing unit 320 may perform image processing of the demultiplexed image signal. To this end, the image processing unit 320 may include an image decoder 225 and a scaler 235.

The video decoder 225 decodes the demultiplexed video signal, and the scaler 235 performs scaling so that the resolution of the decoded video signal can be output from the display 180.

The video decoder 225 may include decoders of various standards.

Meanwhile, the image signal decoded by the image processing unit 320 may be classified into a case where there is only a 2D image signal, a case where a 2D image signal and a 3D image signal are mixed, and a case where there is only a 3D image signal.

For example, when an external video signal input from the external device 190 or a broadcast video signal of a broadcast signal received from the tuner 110 is only a 2D video signal, a 2D video signal and a 3D video signal are mixed , And 3D image signals only, and accordingly, signals are processed by the control unit 170, in particular, the image processing unit 320, and the like, respectively, and a mixed signal of a 2D image signal, a 2D image signal and a 3D image signal, respectively. , 3D image signals may be output.

Meanwhile, the image signal decoded by the image processing unit 320 may be a 3D image signal of various formats. For example, it may be a 3D image signal composed of a color image and a depth image, or may be a 3D image signal composed of a multi-view image signal. The multi-view image signal may include, for example, a left-eye image signal and a right-eye image signal.

Here, the format of the 3D video signal is a side-by-side format in which the left-eye video signal (L) and the right-eye video signal (R) are arranged left and right, and the top-down (Top / Down) format is arranged up and down. Format, Frame Sequential format arranged by time division, Interlaced format that mixes left-eye video signal and right-eye video signal by line, Checker Box that mixes left-eye video signal and right-eye video signal by box It may be a format or the like.

The processor 330 may control overall operations within the image display device 100 or within the controller 170. For example, the processor 330 may control the tuner 110 to select (Tuning) an RF broadcast corresponding to a channel selected by the user or a pre-stored channel.

In addition, the processor 330 may control the image display device 100 by a user command or an internal program input through the user input interface unit 150.

In addition, the processor 330 may control data transmission with the network interface unit 135 or the external device interface unit 130.

In addition, the processor 330 may control operations of the demultiplexer 310, the image processing unit 320, and the OSD generator 340 in the control unit 170.

The OSD generator 340 generates an OSD signal by itself or according to a user input. For example, based on a user input signal, a signal for displaying various types of information as a graphic or text on the screen of the display 180 may be generated. The generated OSD signal may include various data such as a user interface screen, various menu screens, widgets, and icons of the image display device 100. In addition, the generated OSD signal may include a 2D object or a 3D object.

In addition, the OSD generator 340 may generate a pointer that can be displayed on the display based on the pointing signal input from the remote control device 200. In particular, such a pointer may be generated by a pointing signal processing unit, and the OSD generating unit 240 may include such a pointing signal processing unit (not shown). Of course, it is possible that the pointing signal processing unit (not shown) is not provided in the OSD generating unit 240 and is provided separately.

The mixer 345 may mix the OSD signal generated by the OSD generating unit 340 and the decoded image signal processed by the image processing unit 320. In this case, the OSD signal and the decoded image signal may each include at least one of a 2D signal and a 3D signal. The mixed video signal is provided to the frame rate converter 350.

The frame rate converter (FRC) 350 may convert a frame rate of an input image. On the other hand, the frame rate conversion unit 350 may output as it is without any separate frame rate conversion.

The formatter 360 may arrange a left-eye image frame and a right-eye image frame of a 3D image converted at a frame rate. In addition, a synchronization signal Vsync for opening the left-eye glass and the right-eye glass of the 3D viewing apparatus (not shown) may be output.

Meanwhile, the formatter 360 may receive a signal mixed by the mixer 345, that is, an OSD signal and a decoded image signal, and may separate a 2D image signal and a 3D image signal.

Meanwhile, the formatter 360 may change the format of the 3D video signal. For example, it can be changed to any one of the various formats described above.

Meanwhile, the formatter 360 may convert a 2D image signal into a 3D image signal. For example, according to a 3D image generation algorithm, an edge or selectable object is detected in a 2D image signal, and an object or selectable object according to the detected edge is separated into a 3D image signal. I can. In this case, the generated 3D image signal may be separated and aligned into a left-eye image signal L and a right-eye image signal R, as described above.

Meanwhile, although not shown in the drawing, after the formatter 360, a 3D processor (not shown) for processing a 3-dimensional effect signal may be further disposed. Such a 3D processor (not shown) may process brightness, tint, and color adjustment of an image signal in order to improve a 3D effect. For example, it is possible to perform signal processing to make the near field clear and the far field blurry. Meanwhile, the functions of the 3D processor may be merged into the formatter 360 or may be merged into the image processing unit 320.

Meanwhile, an audio processing unit (not shown) in the control unit 170 may perform speech processing of a demultiplexed speech signal. To this end, the audio processing unit (not shown) may include various decoders.

In addition, an audio processing unit (not shown) in the control unit 170 may process a base, a treble, and a volume control.

A data processing unit (not shown) in the control unit 170 may perform data processing of the demultiplexed data signal. For example, when the demultiplexed data signal is an encoded data signal, it may be decoded. The encoded data signal may be EPG (Electronic Program Guide) information including broadcast information such as a start time and an end time of a broadcast program aired on each channel.

Meanwhile, in FIG. 3, the signals from the OSD generation unit 340 and the image processing unit 320 are mixed by the mixer 345 and then 3D processing is performed by the formatter 360, but is not limited thereto. It is also possible for a to be placed after the formatter. That is, the output of the image processing unit 320 is 3D processed by the formatter 360, and the OSD generation unit 340 performs 3D processing along with the OSD generation, and then mixes each processed 3D signal by the mixer 345. It is also possible to do it.

Meanwhile, the block diagram of the control unit 170 shown in FIG. 3 is a block diagram for an embodiment of the present invention. Each component of the block diagram may be integrated, added, or omitted according to the specifications of the controller 170 that is actually implemented.

In particular, the frame rate conversion unit 350 and the formatter 360 are not provided in the control unit 170 and may be provided separately, or may be provided separately as a single module.

4 is a diagram illustrating a control method of the remote control device of FIG. 2.

As illustrated in FIG. 4A, a pointer 205 corresponding to the remote control device 200 is displayed on the display 180.

The user can move or rotate the remote control device 200 up and down, left and right (FIG. 4(b)), back and forth (FIG. 4(c)). The pointer 205 displayed on the display 180 of the image display device corresponds to the movement of the remote control device 200. Since the corresponding pointer 205 is moved and displayed according to movement in 3D space, as shown in the drawing, the remote control device 200 may be referred to as a space remote controller or a 3D pointing device.

4B illustrates that when the user moves the remote control device 200 to the left, the pointer 205 displayed on the display 180 of the image display device also moves to the left in response thereto.

Information on the movement of the remote control device 200 detected through the sensor of the remote control device 200 is transmitted to the image display device. The image display device may calculate the coordinates of the pointer 205 from information about the movement of the remote control device 200. The image display device may display the pointer 205 to correspond to the calculated coordinates.

4C illustrates a case where a user moves the remote control device 200 away from the display 180 while pressing a specific button in the remote control device 200. Accordingly, the selection area in the display 180 corresponding to the pointer 205 can be zoomed in and displayed in an enlarged manner. Conversely, when the user moves the remote control device 200 to be close to the display 180, the selection area in the display 180 corresponding to the pointer 205 may be zoomed out and displayed in a reduced size. On the other hand, when the remote control device 200 moves away from the display 180, the selection area is zoomed out, and when the remote control device 200 approaches the display 180, the selection area may be zoomed in.

On the other hand, when a specific button in the remote control device 200 is pressed, recognition of vertical and horizontal movement may be excluded. That is, when the remote control device 200 moves away from or approaches the display 180, up, down, left, and right movements are not recognized, and only forward and backward movements may be recognized. When a specific button in the remote control device 200 is not pressed, only the pointer 205 moves according to the up, down, left, and right movement of the remote control device 200.

Meanwhile, the moving speed or moving direction of the pointer 205 may correspond to the moving speed or moving direction of the remote control device 200.

5 is an internal block diagram of the remote control device of FIG. 2.

Referring to the drawings, the remote control device 200 includes a wireless communication unit 425, a user input unit 435, a sensor unit 440, an output unit 450, a power supply unit 460, a storage unit 470, It may include a control unit 480.

The wireless communication unit 425 transmits and receives a signal to and from any one of the image display apparatuses according to the embodiments of the present invention described above. Among the image display devices according to embodiments of the present invention, one image display device 100 will be described as an example.

In this embodiment, the remote control device 200 may include an RF module 421 capable of transmitting and receiving signals to and from the image display device 100 according to an RF communication standard. In addition, the remote control device 200 may include an IR module 423 capable of transmitting and receiving signals to and from the image display device 100 according to the IR communication standard.

In this embodiment, the remote control device 200 transmits a signal containing information about the movement of the remote control device 200 to the image display device 100 through the RF module 421.

In addition, the remote control device 200 may receive a signal transmitted from the image display device 100 through the RF module 421. In addition, the remote control device 200 may transmit a command regarding power on/off, channel change, volume change, etc. to the image display device 100 through the IR module 423 as needed.

The user input unit 435 may be composed of a keypad, a button, a touch pad, or a touch screen. A user may input a command related to the image display device 100 to the remote control device 200 by manipulating the user input unit 435. When the user input unit 435 includes a hard key button, the user can input a command related to the image display device 100 to the remote control device 200 through a push operation of the hard key button. When the user input unit 435 includes a touch screen, the user can input a command related to the image display device 100 to the remote control device 200 by touching a soft key on the touch screen. In addition, the user input unit 435 may include various types of input means that a user can manipulate, such as a scroll key or a jog key, and the present embodiment does not limit the scope of the present invention.

The sensor unit 440 may include a gyro sensor 441 or an acceleration sensor 443. The gyro sensor 441 may sense information about the movement of the remote control device 200.

For example, the gyro sensor 441 may sense information about the operation of the remote control device 200 based on the x, y, and z axes. The acceleration sensor 443 may sense information about a moving speed of the remote control device 200. Meanwhile, a distance measurement sensor may be further provided, thereby sensing a distance to the display 180.

The output unit 450 may output an image or audio signal corresponding to an operation of the user input unit 435 or a signal transmitted from the image display apparatus 100. Through the output unit 450, the user may recognize whether the user input unit 435 is manipulated or whether the image display device 100 is controlled.

As an example, the output unit 450 includes an LED module 451 that lights up when a user input unit 435 is manipulated or a signal is transmitted and received with the image display device 100 through the wireless communication unit 425, and a vibration module that generates vibration ( 453), a sound output module 455 that outputs sound, or a display module 457 that outputs an image.

The power supply unit 460 supplies power to the remote control device 200. The power supply unit 460 may reduce power waste by stopping power supply when the remote control device 200 is not moved for a predetermined period of time. The power supply unit 460 may resume power supply when a predetermined key provided in the remote control device 200 is operated.

The storage unit 470 may store various types of programs and application data necessary for controlling or operating the remote control device 200. If the remote control device 200 wirelessly transmits and receives signals through the image display device 100 and the RF module 421, the remote control device 200 and the image display device 100 transmit signals through a predetermined frequency band. Send and receive. The control unit 480 of the remote control device 200 stores information on the image display device 100 paired with the remote control device 200 and a frequency band through which signals can be transmitted and received wirelessly, in the storage unit 470, and You can refer to it.

The controller 480 controls all matters related to the control of the remote control device 200. The control unit 480 transmits a signal corresponding to a predetermined key operation of the user input unit 435 or a signal corresponding to the movement of the remote control device 200 sensed by the sensor unit 440 through the wireless communication unit 425. Can be transmitted to (100).

The user input interface unit 150 of the image display device 100 includes a wireless communication unit 151 capable of transmitting and receiving signals wirelessly with the remote control device 200, and a pointer corresponding to the operation of the remote control device 200. A coordinate value calculator 415 capable of calculating the coordinate value of may be provided.

The user input interface unit 150 may wirelessly transmit and receive signals with the remote control device 200 through the RF module 412. In addition, through the IR module 413, the remote control device 200 may receive a signal transmitted according to the IR communication standard.

The coordinate value calculation unit 415 corrects the hand shake or error from the signal corresponding to the operation of the remote control device 200 received through the wireless communication unit 151 and the coordinate value of the pointer 202 to be displayed on the display 170 (x,y) can be calculated.

The transmission signal of the remote control device 200 input to the image display device 100 through the user input interface unit 150 is transmitted to the controller 180 of the image display device 100. The controller 180 may determine information on an operation of the remote control device 200 and key manipulation from a signal transmitted from the remote control device 200 and control the image display device 100 in response thereto.

As another example, the remote control device 200 may calculate a pointer coordinate value corresponding to the operation and output it to the user input interface unit 150 of the image display device 100. In this case, the user input interface unit 150 of the image display device 100 may transmit information on the received pointer coordinate value to the controller 180 without a separate hand shake or error correction process.

In addition, as another example, the coordinate value calculation unit 415 may be provided inside the control unit 170 instead of the user input interface unit 150 unlike the drawing.

6 is a diagram illustrating an example of an interior of the power supply unit and the display of FIG. 2.

Referring to the drawings, a liquid crystal panel (LCD panel) based display 180 may include a liquid crystal panel 210, a driving circuit unit 230, and a backlight unit 250.

In the liquid crystal panel 210, in order to display an image, a plurality of gate lines GL and data lines DL are intersected in a matrix form, and a thin film transistor and a pixel electrode connected thereto are formed in the intersecting regions It includes a first substrate, a second substrate provided with a common electrode, and a liquid crystal layer formed between the first substrate and the second substrate.

The driving circuit unit 230 drives the liquid crystal panel 210 through 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.

The timing controller 232 receives control signals, R, G, B data signals, vertical synchronization signals (Vsync), and the like from the control unit 170, and corresponds to the control signal to the gate driver 234 and The data driver 236 is controlled, and the R, G, B data signals are rearranged and provided to the data drive 236.

Scan signals and image signals are supplied to the liquid crystal panel 210 through the gate line GL and the data line DL under the control of the gate driver 234, the data driver 236, and the timing controller 232.

The backlight unit 250 supplies light to the liquid crystal panel 210. To this end, the backlight unit 250 turns on/on a plurality of backlight lamps 252 as light sources, a scan driver 254 that controls scanning driving of the backlight lamp 252, and the backlight lamp 252. It may include a lamp driving unit 256 to be turned off.

In a state in which 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 panel 210, a predetermined image is displayed using light emitted from the backlight unit 250.

The power supply unit 190 may supply a common electrode voltage Vcom to the liquid crystal panel 210 and may supply a gamma voltage to the data driver 236. In addition, driving power for driving the backlight lamp 252 may be supplied to the backlight unit 250.

7A to 7D are diagrams illustrating various examples of an arrangement of the backlight lamp of FIG. 6.

First, FIG. 7A illustrates a bar type backlight lamp 252L disposed below the rear side of the liquid crystal panel 210. The backlight lamp 252L may include a plurality of LEDs (light emitting diodes), and includes a diffuser plate for diffusing light, a reflector for reflecting light, and an optical sheet for polarizing, spotting, and diffusing light. Light is irradiated on the front surface of (210).

Next, FIG. 7B illustrates a plurality of bar type backlight lamps 252a and 252b disposed below the rear surface of the liquid crystal panel 210. The backlight lamps 252a and 252b may include a plurality of light emitting diodes (LEDs).

Next, FIG. 7C illustrates a plurality of bar type backlight lamps 252-1, 252-2, 252-3 and 252-4 disposed on the rear, upper and lower sides of the liquid crystal panel 210. The backlight lamps 252-1, 252-2, 252-3, and 252-4 may include a plurality of LEDs (light emitting diodes).

Next, FIG. 7D shows a plurality of bar type backlight lamps 252-1,252-2,252-3,252-4,252-5,252-6 disposed on the rear, upper, lower, and center sides of the liquid crystal panel 210. Illustrate. The backlight lamps 252-1,252-2,252-3,252-4,252-5,252-6 may include a plurality of light emitting diodes (LEDs).

8 is an example of a partial circuit diagram of an image display device according to an embodiment of the present invention, and FIGS. 9 to 12 are views referenced for explanation of the circuit diagram of FIG. 8.

First, referring to FIG. 8, the image display apparatus 100 includes a plurality of backlight lamps Lda,..,Ldn) 1140 and a plurality of backlight lamps Lda,..,Ldn, which are connected in parallel with each other. A power supply unit 190 for supplying common power (VLED) to the 1140, a lamp driving unit 256 for driving a plurality of backlight lamps Lda, .., Ldn 1140, and a lamp driving unit 256. A driving control unit 1120 to control may be provided.

Here, the backlight lamps Lda, .., Ldn each represent a string lamp, and each string lamp may include a plurality of LEDs in series, in parallel, or a mixture thereof.

As described above, as the resolution of the image display device 100 increases to HD (High Definition), Full HD, UHD (Ultra High Definition), 4K, 8K, etc., the number of a plurality of LEDs increases. , The driving voltages Vfa,.., Vfn of each string lamp, that is, the backlight lamps Lda,..,Ldn, are increased. Alternatively, the driving currents Ifa, .., Ifn of each string lamp, that is, the backlight lamps Lda, .., Ldn, are increased. In addition, power consumption consumed by a backlight lamp or a circuit element driving the backlight lamp increases according to the rising LED driving voltage (Vfa, .., Vfn) or driving current (Ifa,.., Ifn).

In particular, as the level of current flowing through the switching elements driving the plurality of backlight lamps increases, power consumption in the switching elements increases, and heat generation increases.

Accordingly, in the present invention, a technique for reducing heat generation of a plurality of switching elements for switching a plurality of backlight lamps when driving a backlight lamp in a high-resolution image display device is described.

The power supply unit 190 outputs a common voltage VLED to a plurality of backlights. To this end, the power supply unit 190 includes a dc/dc converter 1110 for level-converting and outputting DC power, an inductor L for removing harmonics, and a capacitor C for storing DC power. It can be provided with.

The voltage across the capacitor C corresponds to the voltage supplied between the node A and the ground terminal, which includes a plurality of backlight lamps Lda, .., Ldn 1140, and a plurality of switching elements Sa. ,...Sn), and the voltage applied to the resistance elements Ra,...,Rn. That is, the voltage of node A is a common voltage supplied to the plurality of backlight lamps Lda,..,Ldn, and may be referred to as a VLED voltage as shown in the drawing.

The VLED voltage is equal to the sum of the driving voltage Vfa of the first backlight lamp LDa, the voltage across the first switching element Sa, and the voltage consumed by the first resistance element Ra. Alternatively, the VLED voltage is equal to the sum of the driving voltage Vfb of the second backlight lamp LDb, the voltage across the second switching element Sb, and the voltage consumed by the second resistance element Rb. Alternatively, the VLED voltage is equal to the sum of the driving voltage Vfn of the n-th backlight lamp LDn, the voltage across the n-th switching element Sn, and the voltage consumed by the n-th resistance element Rn.

Meanwhile, as the resolution of the panel 210 increases, the backlight driving voltages Vfa,,, and Vfn increase, and the driving currents Ifa,...Ifn flowing through the backlight also increase. Accordingly, power consumed by the plurality of switching elements Sa,...Sn and the resistance elements Ra,...,Rn also increases, and the plurality of switching elements Sa,...Sn ), and the device stress of the resistive elements Ra,...,Rn is also increased.

In order to reduce power consumption when driving the backlight, driving currents Ifa,...Ifn flowing through the plurality of switching elements Sa,...Sn and the resistance elements Ra,...,Rn It is desirable to reduce ). In this case, it is assumed that the backlight driving voltages Vfa,,,Vfn are constant.

To this end, the driving control unit 1120 includes a first voltage detection unit 1132 that detects a voltage VD of each drain terminal G of a plurality of switching elements Sa,...Sn implemented as a FET, or the like. ). The driving control unit 1120 includes a second voltage detection unit 1134 that detects the voltage VG of each gate terminal G, and a third voltage detection unit 1136 that detects the voltage VS of each source terminal S. ) May be further provided.

In addition, the driving control unit 1120 compares the drain terminal voltage VD, detected at each drain terminal G, of the plurality of switching elements Sa,...Sn, and among them, the lowest drain terminal Based on the voltage, target driving currents flowing through the plurality of backlight lamps 1140 may be generated, and a switching control signal SG corresponding to the generated target driving current may be output.

When the switching control signal SG is input to the comparator and is greater than the voltage VD of the detected source terminal, the switching control signal SG is output from the comparator and input to the gate terminal G. Consequently, the switching element is driven based on the switching control signal SG.

On the other hand, in order to generate such a switching control signal, the driving control unit 1120, based on the drain terminal voltages of the plurality of switching elements Sa,...Sn, the plurality of switching elements Sa,... A processor 1130 for generating a switching control signal for driving each gate terminal of Sn) may be included.

The processor 1130 varies the level of the switching control signal SG based on the magnitude of the drain terminal voltage VD of the plurality of switching elements Sa,...Sn.

On the other hand, the processor 1130, based on the magnitude of each drain terminal voltage (VD) of the plurality of switching elements (Sa,...Sn), the level of the switching control signal (SG) and the switching control signal (SG) You can also change the duty of.

Meanwhile, the processor 1130 determines the level of the switching control signal SG based on the lowest drain terminal voltage Vref among the drain terminal voltages VD of the plurality of switching elements Sa,...Sn. It can be variable.

Specifically, the processor 170 may control the level of the switching control signal SG to increase as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases.

Alternatively, the processor 1130, as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases, the level of the switching control signal SG increases, and the duty of the switching control signal SG decreases. Can be controlled to lose.

Meanwhile, the processor 1130 controls the turn-off period of the plurality of switching elements Sa,...Sn to increase as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases. can do.

The processor 170,

Meanwhile, when the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD is within a predetermined value, the processor 1130 may control the level of the switching control signal SG to be constant.

Meanwhile, the processor 1130 includes a level determining unit 1133 that determines a level of the switching control signal SG based on a difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD, and the determined level. A level signal output unit 1131 for outputting the level signal S2 according to the control signal S2, and a duty signal generator 1135 for generating a duty signal S3 according to the level of the switching control signal SG may be included.

9 illustrates an internal block diagram of the processor 1130.

The level determining unit 1133 sets the level of the switching control signal SG to increase as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases.

Then, the level signal output unit 1131 outputs the level signal S2 according to the determined level to the op amp 1137. The op amp 1137 outputs a comparison signal by comparing the detected gate terminal voltage VG and the level signal S2.

On the other hand, the duty signal generator 1135 generates a duty signal S3 for decreasing the duty of the switching control signal SG as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases. Generate. The generated duty signal S3 is output to the output terminal of the op amp 1137.

Accordingly, the switching control signal SG is generated based on the duty signal S3 and a comparison signal having a predetermined level by comparing the detected gate terminal voltage VG and the level signal S2. As described above, the generated switching control signal SG increases the level of the switching control signal SG as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases. The duty of the signal SG becomes small.

Specifically, the processor 1130, based on the lowest drain terminal voltage among the drain terminal voltages of the plurality of switching elements (Sa,...Sn), the target driving current flowing through the plurality of backlight lamps 1140 The generated switching control signal SG corresponding to the generated target driving current may be output to each of the gate terminals G of the plurality of switching elements Sa,...Sn.

At this time, the processor 1130 sequentially compares the drain terminal voltages in units of frames, for example, and based on the lowest drain terminal voltage among the drain terminal voltages, targets flowing through the plurality of backlight lamps 1140 It can generate drive current. That is, a target driving current can be generated in units of frames. Accordingly, the target driving current is sequentially lowered, and thus, power consumption consumed by the plurality of switching elements Sa,...Sn, etc. is sequentially lowered. As a result, power consumption when driving the backlight is reduced.

Meanwhile, when only some of the plurality of backlight lamps are operated by local dimming, the processor 1130 is the lowest among the voltages of each drain terminal of the switching element corresponding to the plurality of lamps operating among the plurality of backlight lamps 1140. Based on the drain terminal voltage, target driving currents flowing through a plurality of lamps operating among the plurality of backlight lamps 1140 are generated, and a switching control signal corresponding to the generated target driving current is transmitted to the plurality of switching elements Sa, ...Sn) can be output to each gate terminal.

At this time, in the processor 1130, as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases, the level of the switching control signal SG increases, and the duty of the switching control signal SG decreases. Can be controlled to lose.

According to this control, the drain terminal voltage VD of the plurality of switching elements Sa,...Sn decreases in sequence, and, as a result, is consumed by the plurality of switching elements Sa,...Sn. The power consumption is sequentially lowered, so that heat generation of the plurality of switching elements Sa,...Sn can be reduced.

That is, the processor 1130 controls the drain terminal voltage VD of the plurality of switching elements Sa,...Sn to decrease sequentially.

On the other hand, such a heat generation reduction technique can be performed only under a load condition of a predetermined value or more. For example, the above-described heat reduction technique may be performed under a load condition in which 75 & more of the operating loads according to the plurality of backlight lamps Lda,..,Ldn operate.

Meanwhile, the processor 1130 may control the level of the common voltage VLED output from the power supply unit 190 to be constant.

Specifically, the processor 1130 is based on the lowest drain terminal voltage among the drain terminal voltages VD of the plurality of switching elements Sa,...Sn, the common voltage output from the power supply unit 190 ( A control signal S1 for level control of the VLED) is generated, and the generated control signal S1 may be output to the power supply unit 190 as an AS1 signal through the comparator 1139. Meanwhile, the AS1 signal is input to the DC/DC converter 190 in the power supply unit 190 and is used as a target common voltage, and the DC/DC converter 190 controls the internal switching element to follow the target common voltage. Thus, the level-converted common voltage VLED is output.

The processor 1130 may generate the control signal S1 so that the level of the common voltage VLED is determined based on the level of the lowest drain terminal voltage for a predetermined period.

In particular, the processor 1130 may generate the control signal S1 so that the level of the output common voltage VLED decreases as the level of the lowest drain terminal voltage decreases.

On the other hand, the processor 1130, when local dimming, when only some of the plurality of backlight lamps are operated, the lowest drain among the voltages of each drain terminal of the switching element corresponding to the plurality of lamps operating among the plurality of backlight lamps 1140 Based on the terminal voltage, a target driving current flowing through a plurality of lamps operating among a plurality of backlight lamps is generated, and a switching control signal (SG2) corresponding to the generated target driving current is output, thereby being consumed even during local dimming driving. Electricity can be reduced.

The switching control signal SG2 at this time, as described above, increases the level of the switching control signal SG as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases, and the switching control signal The duty of (SG) can be reduced.

10A to 12 are views referenced for explanation of the circuit diagram of FIG. 8.

10A shows an ideal value of a driving current flowing through the backlight lamp during backlight driving, a drain voltage VD1 of a first backlight lamp La among a plurality of backlight lamps, a first backlight lamp La or a first The current Ifa flowing through the first switching element Sa driving the backlight lamp La is illustrated.

Ideally, a current of the same level (Iref) flows through the plurality of backlight lamps as shown in FIG. 10A(a). In addition, when driving a plurality of backlight lamps, it is ideal that the LED driving voltage Vf in each backlight lamp is constant. And, it is ideal that the voltages VD1 to VD4 of the drain terminals of each of the switching elements Sa to Sd are the same.

FIG. 10A(b) illustrates that the voltage VD1 of the drain terminal of the first switching element Sa is slightly greater than the reference voltage Vref, and the level is constant for a predetermined time.

In this case, as shown in (c) of FIG. 10A, the magnitude of the current If1 flowing through the first switching element Sa is constant as Iref, and the duty Ton is also constant.

Meanwhile, Psa of FIG. 10A may correspond to a first frame period, Psb may correspond to a second frame period, and Psc may correspond to a third frame period.

However, in practice, when driving a plurality of backlight lamps, voltages VDa to VD4 of drain terminals of each of the switching elements Sa to Sd are different due to a difference between the LED driving voltages Vf in each backlight lamp.

10B is a diagram referred to in the description for the above-described heat reduction technique, and among a plurality of backlight lamps, the drain voltage VD1 of the first backlight lamp La, the first backlight lamp La, or the first backlight lamp ( The current If1 flowing through the first switching element Sa driving La) is illustrated.

Meanwhile, FIG. 11 is a diagram illustrating an example of an operation of a plurality of lamps.

For example, the current If1 flowing through the first backlight lamp La is 105 mA, the current If2 flowing through the second backlight lamp Lb is 100 mA, and the current flowing through the third backlight lamp Lc When (If3) is 110 mA and the current If4 flowing through the fourth backlight lamp Ld is 105 mA, when the resistance elements Ra, Rb, Rc, Rd are 80 Ω, the first to fourth drains The voltages VD1 to VD4 respectively detected at the terminals are, in order, 0.84V, 0.8V, 0.88V, and 0.84V.

Since the second drain terminal voltage among the detected drain voltages is the lowest voltage, the processor 1130 determines the level of the switching control signal SG based on the lowest voltage of 0.8V.

In particular, the processor 1130 determines the level of the switching control signal SG based on the difference between the lowest drain terminal voltage Vref=VD2 and the respective drain terminal voltages VD1, VD3, and VD4.

Specifically, as the difference between the lowest drain terminal voltage Vref and each of the drain terminal voltages VD1, VD3, and VD4 increases, the level of the switching control signal SG is controlled to increase. In addition, the duty of the switching control signal SG is reduced.

Accordingly, the level of the switching control signal SG input to the third switching element Sc is set to the largest and the turn-on duty is set to the smallest based on 0.08V, which is the difference from the lowest drain terminal voltage.

On the other hand, based on 0.04V, which is the difference from the lowest drain terminal voltage, the level of the switching control signal SG input to the first and fourth switching elements Sa and Sd is input to the third switching element Sc. It is set to be smaller than the level of the switching control signal SG, and the turn-on duty is set to be larger.

Hereinafter, it will be described based on the first backlight lamp.

During the first frame period PSa of FIG. 10B, when the first drain terminal voltage VD1 is VD1a and the difference from the lowest drain terminal voltage Vref is VDfa, which is greater than or equal to the reference value, the processor 1130 will: During the second frame period PSb, which is the frame period, the current If1 flowing through the first backlight lamp La is controlled to increase. That is, the switching control signal SG is controlled to increase the level.

In the drawing, it is exemplified that the current of Ir2, which is greater than the Ir1 level, flows through the first backlight lamp La during the second frame period PSb during the first frame period PSa, in which current control is not performed. do.

Meanwhile, in order to reduce an increase in power consumption due to an increase in the current level, it is preferable to decrease the turn-on duty in inverse proportion to the increase in the current level. That is, it is possible to increase the turn-off duty.

Accordingly, during the first frame period PSa in which current control is not performed, the turn-on duty Ton2 is smaller than the turn-on duty of Ton1, and during the second frame period PSb, the first backlight lamp ( It is preferable to flow in La).

By this current control, during the second frame period PSb, the first drain terminal voltage VD1 has a level VD1b that is smaller than the VD1a level during the first frame period PSa.

During the second frame period PSb of FIG. 10B, when the first drain terminal voltage VD1 is VD1b and the difference from the lowest drain terminal voltage Vref is VDfb, which is greater than or equal to the reference value, the processor 1130 will: During the frame period, the third frame period PSc, the current If1 flowing through the first backlight lamp La is controlled to increase. That is, the switching control signal SG is controlled to increase the level.

In the drawing, it is exemplified that the current of Ir3, which is greater than the Ir2 level, flows through the first backlight lamp La during the second frame period PSb in which current control is performed, during the third frame period PSc. .

Meanwhile, in order to reduce an increase in power consumption due to an increase in the current level, it is preferable to decrease the turn-on duty in inverse proportion to the increase in the current level. That is, it is possible to increase the turn-off duty.

Accordingly, during the second frame period PSb in which current control is performed, the turn-on duty Ton3 is smaller than the turn-on duty of Ton2, and during the third frame period PSc, the second backlight lamp Lb It is desirable to flow in ).

By this current control, during the third frame period PSb, the first drain terminal voltage VD1 has a level VD1c that is smaller than the VD1b level during the second frame period PSb.

On the other hand, during the third frame period PSb, when the first drain terminal voltage VD1 is VD1c and the difference from the lowest drain terminal voltage Vref is VDfc, which is less than the reference value, the processor 1130, the next frame From the period, the current of Ir3 flows through the first backlight lamp La. That is, current control can be locked.

Accordingly, the first drain terminal voltage VD1 after the third frame period PSb may be VD1c.

Meanwhile, in the case of controlling the current If1 flowing through the first backlight lamp La based on the difference between the first drain terminal voltage VD1 and the lowest drain terminal voltage Vref in FIG. 10B, the processor ( 1130, based on the magnitudes of the drain terminal voltages VD of the plurality of switching elements Sa,...Sn, vary the level of the switching control signal SG and vary the turn-on duty.

That is, the processor 1130 controls the level of the switching control signal SG to increase as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases, and the turn-on duty decreases. do.

Further, the processor 1130 controls the product of the level of the switching control signal and the duty of the switching control signal to be constant.

Referring to FIG. 10B, the drain terminal voltage VD1 is sequentially decreased, and thus, heat generation of a plurality of switching elements for switching a plurality of backlight lamps can be reduced.

Meanwhile, FIG. 12 is a diagram illustrating another example of an operation of a plurality of lamps.

In particular, FIG. 12 illustrates that the first backlight lamp La does not operate, and only the second to fourth backlight lamps Lb, Lc, and Ld operate by local dimming.

For example, the current If1 flowing through the first backlight lamp La is 0 mA, the current If2 flowing through the second backlight lamp Lb is 100 mA, and the current flowing through the third backlight lamp Lc When (If3) is 105 mA and the current If4 flowing through the fourth backlight lamp Ld is 110 mA, when the resistance elements Ra, Rb, Rc, Rd are 80 Ω, the second to fourth drains The voltages VD respectively detected at the terminals become 0.8V, 0.84V, and 0.88V in that order.

Since the second drain terminal voltage among the detected drain voltages is the lowest voltage, the processor 1130 determines the level of the switching control signal SG based on the lowest voltage of 0.8V.

In particular, the processor 1130 determines the level of the switching control signal SG based on the difference between the lowest drain terminal voltage Vref=VD2 and the respective drain terminal voltages VD1, VD3, and VD4. Specifically, as the difference between the lowest drain terminal voltage Vref and each of the drain terminal voltages VD1, VD3, and VD4 increases, the level of the switching control signal SG is controlled to increase.

In particular, the processor 1130 determines the level of the switching control signal SG based on the difference between the lowest drain terminal voltage Vref=VD2 and the respective drain terminal voltages VD3 and VD4.

Specifically, as the difference between the lowest drain terminal voltage Vref and the respective drain terminal voltages VD3 and VD4 increases, the level of the switching control signal SG is controlled to increase. In addition, the duty of the switching control signal SG is reduced.

Accordingly, the level of the switching control signal SG input to the fourth switching element Sd is set to the largest and the turn-on duty is set to the smallest based on 0.08V, which is the difference from the lowest drain terminal voltage.

On the other hand, based on 0.04V, which is the difference from the lowest drain terminal voltage, the level of the switching control signal SG input to the third switching element Sc is the switching control signal input to the fourth switching element Sd ( SG) is set to be smaller than the level, and the turn-on duty is set to be larger.

13 is another example of a partial circuit diagram of an image display device according to an embodiment of the present invention, and FIG. 14 is a diagram referenced for explanation of the circuit diagram of FIG. 13.

The partial circuit diagram of the image display device of FIG. 13 is similar to the circuit diagram of FIG. 8, but the difference is that the temperature detection unit 1138 is further provided in the driving control unit 1120. Hereinafter, the differences will be mainly described.

The temperature detection unit 1138 detects temperatures around the plurality of backlight lamps 1140. As the temperature of the backlight lamp 1140 increases, the driving voltage Vf decreases, and thus the driving current If may increase within a predetermined range. Therefore, the temperature of the backlight lamp 1140 becomes an important factor when controlling backlight driving.

The processor 1130 may compensate the level of the switching control signal SG based on temperatures around the plurality of backlight lamps 1140. Specifically, the processor 1130 may control the level of the switching control signal SG to increase as the temperature around the plurality of backlight lamps 1140 increases. In addition, it is possible to control the duty of the switching control signal SG to decrease.

In this way, the processor 1130 controls the level of the switching control signal SG generated by the processor 1130 to decrease sequentially, and compensates the level of the switching control signal SG as the temperature around the backlight lamp increases. For this purpose, by increasing the level of the switching control signal SG, it is possible to reduce power consumption and heat generation while stably driving the backlight lamp according to the ambient temperature.

FIG. 14 is similar to FIG. 10B, except that temperature compensation is further performed.

During the first frame period PSa of FIG. 14, when the first drain terminal voltage VD1 is VD1aa and the difference from the lowest drain terminal voltage Vref is VDfaa, which is greater than or equal to the reference value, the processor 1130 will: During the second frame period PSb, which is the frame period, the current If1 flowing through the first backlight lamp La is controlled to increase. That is, the switching control signal SG is controlled to increase the level.

In the drawing, the current of Ir2a (Ir2a>Ir2) greater than the Ir1 level during the first frame period PSa in which the current control is not performed, during the second frame period PSb, the first backlight lamp La ) To illustrate the flow.

Meanwhile, in order to reduce an increase in power consumption due to an increase in the current level, it is preferable to decrease the turn-on duty in inverse proportion to the increase in the current level. That is, it is possible to increase the turn-off duty.

Accordingly, during the first frame period PSa, in which current control is not performed, with a turn-on duty Ton2a smaller than the turn-on duty of Ton1a (Ton1a<Ton1), during the second frame period PSb, It is preferable to flow through the first backlight lamp La.

By this current control, during the second frame period PSb, the first drain terminal voltage VD1 has a level VD1ba that is smaller than the VD1aa level during the first frame period PSa.

During the second frame period PSb of FIG. 14, when the first drain terminal voltage VD1 is VD1ba and the difference from the lowest drain terminal voltage Vref is VDfba, which is greater than or equal to the reference value, the processor 1130 will: During the frame period, the third frame period PSc, the current If1 flowing through the first backlight lamp La is controlled to increase. That is, the switching control signal SG is controlled to increase the level.

In the drawing, it is exemplified that the current of Ir3a, which is greater than the Ir2a level, flows through the first backlight lamp La during the second frame period PSb, in which current control is performed, during the third frame period PSc. .

Meanwhile, in order to reduce an increase in power consumption due to an increase in the current level, it is preferable to decrease the turn-on duty in inverse proportion to the increase in the current level. That is, it is possible to increase the turn-off duty.

Accordingly, during the second frame period PSb in which the current control is performed, the turn-on duty Ton3a is smaller than the turn-on duty of Ton2a, and during the third frame period PSc, the second backlight lamp Lb It is desirable to flow in ).

By this current control, during the third frame period PSb, the first drain terminal voltage VD1 has a level VD1c that is smaller than the VD1b level during the second frame period PSb.

On the other hand, during the third frame period PSb, when the first drain terminal voltage VD1 is VD1ca and the difference from the lowest drain terminal voltage Vref is VDfca, which is less than the reference value, the processor 1130, the next frame From the period, the current of Ir3a flows through the first backlight lamp La. That is, current control can be locked.

Accordingly, the first drain terminal voltage VD1 after the third frame period PSb may be VD1ca.

Meanwhile, in FIG. 14, when controlling the current If1 flowing through the first backlight lamp La based on the difference between the first drain terminal voltage VD1 and the lowest drain terminal voltage Vref, the processor ( 1130, based on the magnitudes of the drain terminal voltages VD of the plurality of switching elements Sa,...Sn, vary the level of the switching control signal SG and vary the turn-on duty.

That is, the processor 1130 controls the level of the switching control signal SG to increase as the difference between the lowest drain terminal voltage Vref and each drain terminal voltage VD increases, and the turn-on duty decreases. do.

Further, the processor 1130 controls the product of the level of the switching control signal and the duty of the switching control signal to be constant.

Referring to FIG. 14, the drain terminal voltage VD1 is sequentially decreased, and thus, heat generation of a plurality of switching elements for switching a plurality of backlight lamps can be reduced.

Meanwhile, the method of operating an image display device of the present invention can be implemented as a code that can be read by a processor on a recording medium that can be read by a processor provided in the image display device. The processor-readable recording medium includes all types of recording devices that store data that can be read by the processor. Examples of recording media that can be read by the processor include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc., and also include those implemented in the form of carrier waves such as transmission through the Internet. . In addition, the processor-readable recording medium is distributed over a computer system connected through a network, so that the processor-readable code can be stored and executed in a distributed manner.

In addition, although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

Claims (19)

panel;
A plurality of backlight lamps outputting light to the panel;
A power supply for outputting a common voltage to the plurality of backlights;
A lamp driver for driving the plurality of backlight lamps by using the common voltage; And
Includes; a driving control unit for controlling the lamp driving unit,
The lamp driving unit,
Including; a plurality of switching elements for switching the plurality of backlight lamps,
The driving control unit,
A processor for generating a switching control signal for driving each gate terminal of the plurality of switching elements, based on the voltages of each drain terminal of the plurality of switching elements,
The processor,
Varying the level of the switching control signal based on the magnitude of the drain terminal voltage,
When the drain terminal of the second switching element among the plurality of switching elements is the lowest drain terminal voltage and the drain terminal voltage of the third switching element is the maximum drain terminal voltage, input to the drain terminal of the third switching element The level of the switching control signal to be turned on is the first level, the turn-on duty is set to the first duty,
When the voltage of the drain terminal of the first switching element is the second largest, the level of the switching control signal input to the drain terminal of the first switching element is a second level less than the first level, and the turn-on duty is An image display device, characterized in that the second duty is set to be greater than the first duty. The method of claim 1,
The processor,
And varying the level of the switching control signal and the duty of the switching control signal based on the level of the drain terminal voltage. The method of claim 1,
The processor,
And controlling the product of the level of the switching control signal and the duty of the switching control signal to be constant. delete The method of claim 1,
The processor,
Based on the lowest drain terminal voltage among the drain terminal voltages of the plurality of switching elements, target driving currents flowing through the plurality of backlight lamps or the plurality of switching elements are generated, and corresponding to the generated target driving currents Based on the switching control signal, output to each gate terminal of the plurality of switching elements,
The processor,
Control so that the level of the common voltage output from the power supply is constant,
The image display device, characterized in that, as the difference between the lowest drain terminal voltage and each of the drain terminal voltages increases, the level of the switching control signal increases and the duty of the switching control signal decreases. delete The method of claim 5,
The processor,
The image display device, characterized in that, as the difference between the lowest drain terminal voltage and the respective drain terminal voltages increases, the turn-off period of the switching element is controlled to increase. The method of claim 5,
The processor,
And controlling the level of the switching control signal to be constant when the difference between the lowest drain terminal voltage and the respective drain terminal voltages is within a predetermined value. The method of claim 5,
The processor,
A level determining unit determining a level of the switching control signal based on a difference between the lowest drain terminal voltage and each of the drain terminal voltages;
A level signal output unit outputting a level signal according to the determined level;
And a duty signal generator that generates a duty signal according to the level of the switching control signal. The method of claim 9,
The driving control unit,
And outputting the switching control signal generated based on the level signal and the duty signal. The method according to any one of claims 1 to 3, 4 to 5, and 7 to 10,
The processor,
And compensating for a level of the switching control signal based on temperatures around the plurality of backlight lamps. The method of claim 11,
The processor,
The image display device, characterized in that as the temperature around the plurality of backlight lamps increases, the level of the switching control signal is controlled to increase. The method of claim 11,
The driving control unit,
And a temperature detector configured to detect temperatures around the plurality of backlight lamps. The method of claim 1,
The driving control unit,
A first voltage detector configured to detect voltages of the drain terminals of the plurality of switching elements;
A second voltage detector configured to detect voltages of each of the gate terminals of the plurality of switching elements; And
And a third voltage detector configured to detect voltages of each source terminal of the plurality of switching elements. panel;
A plurality of backlight lamps outputting light to the panel and connected in parallel with each other;
A power supply for outputting a common voltage to the plurality of backlights;
A lamp driver driving the plurality of backlight lamps; And
Includes; a driving control unit for controlling the lamp driving unit,
The lamp driving unit,
Including; a plurality of switching elements for switching the plurality of backlight lamps,
The driving control unit,
A switching control signal for driving each gate terminal of the plurality of switching elements is generated based on a lowest drain terminal voltage among the voltages of each drain terminal of the plurality of switching elements, wherein the lowest drain terminal voltage and the respective drain terminal voltage Including; a processor for varying the level and duty of the switching control signal according to the difference therebetween,
When the drain terminal of the second switching element among the plurality of switching elements is the lowest drain terminal voltage and the drain terminal voltage of the third switching element is the maximum drain terminal voltage, input to the drain terminal of the third switching element The level of the switching control signal to be turned on is the first level, the turn-on duty is set to the first duty,
When the voltage of the drain terminal of the first switching element is the second largest, the level of the switching control signal input to the drain terminal of the first switching element is a second level less than the first level, and the turn-on duty is An image display device, characterized in that the second duty is set to be greater than the first duty. The method of claim 15,
The processor,
The image display device, characterized in that, as the difference between the lowest drain terminal voltage and each of the drain terminal voltages increases, the level of the switching control signal increases and the duty of the switching control signal decreases. The method of claim 15,
The processor,
The image display device, characterized in that, as the difference between the lowest drain terminal voltage and the respective drain terminal voltages increases, the turn-off period of the switching element is controlled to increase. The method of claim 15,
The processor,
And controlling the level of the switching control signal to be constant when the difference between the lowest drain terminal voltage and the respective drain terminal voltages is within a predetermined value. The method according to any one of claims 15 to 18,
The processor,
And compensating for a level of the switching control signal based on temperatures around the plurality of backlight lamps.

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