KR101654235B1 - Display Device and Back Light Unit - Google Patents

Abstract

An embodiment of the present invention includes a power supply unit; A light source including light emitting units that are supplied with power from a power source unit and provide light to the panel; Light source drivers driving the light sources and including a transistor and a resistor; And a light source control unit driving the light source driving units and monitoring at least one of the light source driving units to prevent an excessive rise of power outputted from the power source unit.

Description

A display device and a backlight unit

An embodiment of the present invention relates to a display device and a backlight unit.

As the information technology is developed, the market of the display device which is a connection medium between the user and the information is increasing. Various planar display devices have been put into practical use in response to this.

A flat type display device includes a light-receiving type display device using light provided from a backlight unit. The backlight unit is implemented by an edge type backlight unit, a dual type backlight unit, and a direct type backlight unit to provide light to the display panel.

Some of the conventional backlight units include a plurality of light emitting diodes connected in series as one string and drive them by a driving circuit. The driving circuit detects the current from each string and supplies it to the power supply unit so that the power supply unit that supplies power supplies a stable constant current to the strings.

However, in the conventional backlight unit, when a sensing resistor configured to detect a current from the strings is short-circuited due to factors (dust or the like) generated during the manufacturing process or during use, an overcurrent is generated, It can not be solved and its improvement is required.

According to an embodiment of the present invention for solving the problems of the background art described above, even when a problem such as a short circuit occurs in a sensing resistor constituting a light source driving unit including a backlight unit in manufacturing and driving a display device, And to provide a display device capable of protecting a device and maintaining reliability.

According to an embodiment of the present invention, A light source including light emitting units that are supplied with power from a power source unit and provide light to the panel; Light source drivers driving the light sources and including a transistor and a resistor; And a light source control unit driving the light source driving units and monitoring at least one of the light source driving units to prevent an excessive rise of power outputted from the power source unit.

The light source control unit may include a monitor unit that performs monitoring through a drain terminal of the transistor and inactivates at least one light source driving unit when the power source output from the power source unit rises excessively.

The light source control unit monitors at least one of the light source driving units and can switch to a protection mode in which at least one light source driving unit is inactivated when a voltage excessively increased for at least two seconds.

The light source control unit can not drive the transistor when the output power of the power source unit rises excessively.

An overpowering of the output of the power supply part may be caused by a short circuit of the resistor.

The light source control unit can determine that the output power of the power source unit has risen excessively if the monitored voltage is maintained for at least 2 seconds longer than 8V.

The light source control unit may include a voltage divider for lowering the level of the monitored voltage through the drain terminal of the transistor and an analog-to-digital converter for determining whether the output power of the power source unit rises by the voltage supplied through the voltage divider.

According to another aspect of the present invention, Light sources including light emitting units that are supplied with power from a power supply unit and emit light; Light source drivers driving the light sources and including a transistor and a resistor; And a light source control unit driving the light source driving units and monitoring at least one of the light source driving units to prevent an excessive rise of power outputted from the power source unit.

The light source control unit may perform monitoring through the drain terminal of the transistor and may inactivate at least one light source driving unit when the power source output from the power source unit rises excessively.

The light source control unit may not drive at least one light source driving unit when a voltage that has been excessively increased for at least two seconds.

The light source control unit may not drive the transistors included in the light source driving units when the output power of the power source unit rises excessively.

The output power surge of the power supply part may be caused by a short circuit of the resistor included in the light source driving parts.

The light source control unit can determine that the output power of the power source unit has risen excessively if the monitored voltage is maintained for at least 2 seconds longer than 8V.

The light source control unit may include a voltage divider for lowering the level of the monitored voltage through the drain terminal of the transistor and an analog-to-digital converter for determining whether the output power of the power source unit rises by the voltage supplied through the voltage divider.

In the embodiment of the present invention, when a display device is manufactured and driven, even if a problem such as a short circuit occurs in a sensing resistor constituting a light source driving unit including a backlight unit, damage to circuits constituting the backlight unit is prevented, And a display device capable of maintaining reliability in addition to the above advantages.

1 is a schematic block diagram of a display device according to an embodiment of the present invention;
2 is a schematic block diagram for explaining a display module unit and a backlight driving unit;
3 is a block diagram for explaining an apparatus for driving a backlight unit according to an embodiment of the present invention;
4 is a diagram illustrating a configuration example of a dimming control unit and a light source control unit;
5 is a schematic block diagram of a backlight unit according to an embodiment of the present invention.
6 is a waveform diagram for explaining a protection mode;
7 is a flowchart for explaining the protection mode driving;
8 is a view for explaining an edge type backlight unit;
9 is a perspective view of a display device including an edge type backlight unit.
10 is a view for explaining a dual type backlight unit;
11 is a perspective view of a display device including a dual type backlight unit.
12 is a view for explaining a quad-type backlight unit;
13 is a perspective view of a display device including a quad-type backlight unit.
14 is a view for explaining a direct-type backlight unit;
15 is a perspective view of a display device including a direct-type backlight unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram of a display apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic block diagram illustrating a display module unit and a backlight driving unit.

1, a display device according to an exemplary embodiment of the present invention includes a system board unit 100, a power supply unit 170, and a display module unit 150. [ The devices included in the system board unit 100, the power generating unit 170, and the display module unit 150 will be schematically described as follows.

The system board unit 100 includes a tuner unit 1, a demultiplexing unit 2, a voice decoder unit 3, a voice output unit 4, a video decoder unit 5, a user input unit 6, a memory unit 7, a main control unit 8, an OSD processing unit 9, a signal transmission unit 10, and a dimming control unit 11. The tuner unit 1 selects and outputs a broadcast signal having a frequency band selected by the main control unit 8 from broadcast signals received from an antenna, cable, satellite, or the like. The demultiplexing unit 2 demultiplexes the broadcasting signal provided from the tuner unit 1 into a video signal and a voice signal. The voice decoder unit 3 decodes the compression-coded voice signal supplied from the demultiplexing unit 2 and restores the original voice signal. The audio output unit 4 outputs the audio signal supplied from the audio decoder unit 3 to a speaker or the like. The video decoder 4 decodes the compressed video signal supplied from the demultiplexer 2, and restores and scales the original video signal. The user input unit 6 receives a broadcast channel registration, a broadcast channel change, and the like through a user's operation and generates an input signal corresponding to a user's operation. The user input unit 6 may include a remote controller, an input button formed outside the display device, a touch screen, or the like. When the user input unit 6 is a remote controller, it can generate a menu selection signal corresponding to a signal wirelessly received from the remote controller and supply it to the main control unit 8. [ The main control unit 8 controls the operation of the devices connected to the main control unit 8 by using data or information stored in the memory unit 7 formed inside or outside according to the input signal inputted through the user input unit 6 And performs reception of a broadcast signal and image processing. The main control unit 8 can process data to store and edit broadcast channels and images displayed on the display module unit 150 using a memory unit 7 formed inside or outside. The OSD processing unit 9 outputs an OSD signal for outputting a menu, a sample image, a symbol, a character, a number, etc., which can be selected by the user, as an OSD image. The signal transmitting unit 10 transmits a video signal or the like to the display unit 15 through the interface. The dimming control unit 11 generates a dimming control signal in conjunction with the main control unit 8 and controls the backlight driving unit 16 using the generated dimming control signal. Here, the tuner unit 1, the demultiplexing unit 2, the audio decoder unit 3, the audio output unit 4, the video decoder unit 5, the user input unit 6, the memory unit 7, At least one of the OSD processing unit 8, the OSD processing unit 9, the signal transmission unit 10, and the dimming control unit 11 may be integrated into one chip.

The display module unit 150 is driven based on a video signal and a dimming control signal supplied through an interface. The display module unit 150 includes a display unit 15 for displaying an image based on a video signal and a backlight driver 16 for controlling a backlight unit for providing light to the display unit 15 based on the dimming control signal. The display unit 15 includes a liquid crystal display panel for displaying an image and a backlight unit for providing light to the liquid crystal panel.

The power generation unit 170 includes a power supply unit 17 that converts power supplied from the outside and supplies the converted power to the system board unit 100 and the display module unit 150. The power supply unit 17 converts the AC power supplied from the outside into a plurality of DC power. The devices included in the system board unit 100 and the display module unit 150 are driven based on the power supplied from the power generator 170.

As shown in FIG. 2, the display module unit 150 includes a display unit 15 and a backlight driver 16. The display unit 15 includes a timing controller 121, a data driver 123, a gate driver 125, a liquid crystal panel 126, and a backlight unit 130.

The timing controller 121 receives a video signal RGB, a vertical synchronization signal Vsync, and a horizontal synchronization signal Hsync from the system board unit 100 through a Low Voltage Differential Signaling (LVDS) interface or a Transition Minimized Differential Signaling ), A data enable signal (Data Enable, DE), and a dot clock signal (CLK). The timing controller 121 not only supplies the video signal RGB to the data driver 123 but also generates a data timing signal for controlling the data driver 123 using the timing signals Vsync, Hsync, DE and CLK, A sampling clock (SSC), a source output enable (SOE) signal, and a polarity control signal (POL). The timing controller 121 controls the gate driver 125 such as a gate timing signal such as a gate start pulse GSP, a gate shift clock GSC, a gate output enable signal Gate Output Enable, GOE). The data driver 123 samples and latches the image signal RGB based on the data timing signals SSC, SOE, and POL supplied from the timing controller 121, and converts the image signal RGB into data of a parallel data system. The data driver 123 converts the video signal RGB converted into the parallel data transmission scheme into positive / negative data voltages to be charged in the liquid crystal cells using the positive / negative gamma reference voltages, (D1 to Dm). The gate driver 125 sequentially shifts the gate driving voltage in response to the gate timing signals GSP, GSC, and GOE supplied from the timing controller 121 and sequentially supplies the gate driving voltages to the gate lines G1 to Gn.

The liquid crystal panel 126 includes a transistor substrate and a color filter substrate bonded together with a liquid crystal layer therebetween. The liquid crystal panel 126 includes a pixel array arranged in a matrix form to display an image. The pixel array is formed at each intersection of the data lines D1 to Dm and the gate lines G1 to Gn and includes a thin film transistor TFT, a storage capacitor Cst, a pixel electrode 1, a common electrode 2 And a liquid crystal cell Clc. An alignment film for setting a pre-tilt angle of liquid crystal is formed inside the transistor substrate and the color filter substrate constituting the liquid crystal panel 126, and a polarizer is attached to the outside. The liquid crystal mode of the liquid crystal panel 126 is not limited to TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, IPS (In-Plane Switching) mode, FFS (Fringe Field Switching), ECB (Electrically Controlled Birefringence) . ≪ / RTI >

The backlight unit 130 includes light sources arranged to provide light to the liquid crystal panel 126 and divided into a plurality of light source groups. The light sources included in the backlight unit 130 are controlled by the backlight driving unit 16.

The backlight driving unit 16 includes a light source control unit 141 and light source driving units 145. The light source control unit 141 controls the light source drivers 145 based on the dimming signals DOS and DIM supplied from the main control unit 8 and the dimming control signal SCM supplied from the dimming control unit 11, Unit 130 to operate in global dimming or local dimming mode. In addition, the light source control unit 141 monitors at least one of the light source driving units 145 to prevent an excessive rise of the power supplied to the light sources included in the backlight unit 130. The light source drivers 145 drive the light sources included in the backlight unit 130 based on the light source driving signal SCD supplied from the light source controller 141.

Hereinafter, the devices for driving the backlight unit will be described.

FIG. 3 is a block diagram for explaining an apparatus for driving a backlight unit according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating a configuration of a dimming control unit and a light source control unit.

3 and 4, the main control unit 8 generates dimming signals DOS and DIM based on the video signal and supplies the generated dimming signals DOS and DIM to the light source control unit 141. [ The main control unit 8 also generates a dimming driving signal SCL including a vertical synchronizing signal Vsync and supplies the dimming driving signal SCL to the dimming control unit 11. [ The first dimming signal DOS selectively activates one of the first to Nth light source control units 141a to 141n as an activation signal DOS for controlling whether the light source control unit 141 is driven or not . The second dimming signal DIM is a dimming signal DIM for controlling the light source driving signal SCD output from the light source control unit 141. The dimming signal DIM controls the first to Nth light source control units 141a to 141n, The duty ratio of the DC-DC converter is determined. Here, the second dimming signal DIM is generated in the form of a PWM (Pulse Width Modulation) signal. The first to Nth light source control units 141a to 141n are driven according to the duty of the PWM signal, The dimming duties of the transistors 145a to 145n are different from each other. Therefore, the operation for activating or deactivating the driving of the first to Nth light source control units 141a to 141n is determined according to the waveform of the first dimming signal DOS, and the operations of the first to Nth light source drivers 145a To 145n are determined according to the duty of the second dimming signal DIM.

The dimming control unit 11 generates a vertical synchronization signal Vsync and dimming data S-in for controlling the backlight unit 130 in the local dimming mode on the basis of the dimming driving signal SCL supplied from the main control unit 8, And a data clock (S-CLK), and supplies the dimming control signal (SCM) to the light source control unit 141.

The light source control unit 141 controls the light source drivers 145 according to the dimming signals DOS and DIM supplied from the main control unit 8 and the dimming control signal SCM supplied from the dimming control unit 11. The light source control unit 141 may be divided into first to Nth light source drivers 145a to 145n and may be controlled by a dimming control unit 11 such as a local peripheral interface (SPI) (M_SPIO, S_SPIO to M_SPIn , S_SPIn, and the like. The reason for using the short distance communication (M_SPIO, S_SPIO to M_SPIn, S_SPIn) is that the dimming control unit 11 assigns addresses to individually control the first to Nth light source drivers 145a to 145n, . The first to Nth light source drivers 145a to 145n are respectively assigned different addresses so that only the device selected by the dimming control signal SCM supplied from the dimming control unit 11 is driven. The light source controller 141 configured as described above controls the light source drivers 145 such that the backlight unit 130 operates in a global dimming mode or a local dimming mode. For example, the light source control unit 141 may request only the dimming signals DOS and DIM to control the light source drivers 145 in the global dimming mode. In this case, the light source control unit 141 refers to the vertical synchronization signal Vsync included in the dimming signals DOS and DIM to drive the light source drivers 145 so that all the light sources included in the backlight unit 130 emit light . At this time, the brightness of the light sources 128a to 128x included in the backlight unit 130 may vary according to the duty of the second dimming signal DIM included in the dimming signals DOS and DIM. Alternatively, the light source control unit 141 may request the dimming signals DOS and DIM and the dimming control signal SCM to control the light source drivers 145 in the local dimming mode. In this case, the light source control unit 141 refers to the vertical synchronization signal Vsync included in the dimming signals DOS and DIM so that some of the light sources 128a to 128x included in the backlight unit 130 emit light individually The light source driving units 145 are driven. At this time, the brightness of the light sources 128a to 128x included in the backlight unit 130 is controlled such that the duty of the second dimming signal DIM included in the dimming signals DOS and DIM and the brightness of the second dimming signal DIM included in the dimming control signal SCM And may vary depending on the calculation result value of the dimming data (S-in). The light source control unit 141 may monitor at least one of the light source drivers 145 to prevent excessive power from being supplied to the light sources 128a to 128x included in the backlight unit 130 Will be described in more detail below.

The light source driving units 145 generate the gate signals GC1 to GCn according to the light source driving signal SCD supplied from the light source control unit 141 to generate the light sources 128a to 128x included in the backlight unit 130 The light is emitted in the global dimming mode or the local dimming mode. One light source driver 145a may be configured to drive N (N is one or more) light sources 128a to 128c, for example. However, the light source driving unit is not limited to this, and may be configured to drive at least one light source unit.

The light sources 128a to 128x emit light in accordance with the DC output voltage Vo supplied from the power supply 147 and the gate signals GC1 to GCn supplied from the light source drivers 145. [ The power source unit 147 may supply one of the power sources output from the power source unit 17 as an input voltage Vin and convert the same into a DC output voltage Vo, have. N light sources 128a through 128x may be composed of N light sources group (Gr1), for example, N light sources (N is one or more), for example, three light sources 128a through 128c. However, the light sources are not limited to this, and at least one light source unit may be composed of one light source group. One light source unit 128a includes first to Nth light emitting units D1 to Dn. The first to Nth light emitting units D1 to Dn may include at least two light emitting diodes connected in series, but the present invention is not limited thereto. For example, the number of the light emitting diodes constituting the first to Nth light emitting units D1 to Dn may be 4 to 12 or more depending on the size of the liquid crystal panel. The light sources 128a to 128x included in the first to Nth light source groups Gr1 to Grn are driven in the global dimming mode according to the gate signals GC1 to GCn supplied from the light source drivers 145 All are emitted or driven in the local dimming mode to emit light individually. In the following description, one light source group may be defined as one substrate unit, and the light sources included in one light source group may be defined as the minimum unit light emitting units each capable of individually controlling, that is, one light emitting diode package unit Can be defined. Here, the light sources are formed in a configuration in which one or more light source groups are formed and mounted on the first substrate to the Nth substrate (N is an integer of two or more).

Hereinafter, the backlight unit according to one embodiment of the present invention will be described in more detail.

FIG. 5 is a schematic block diagram of a backlight unit according to an embodiment of the present invention, FIG. 6 is a waveform diagram for explaining a protection mode, and FIG. 7 is a flowchart for illustrating a protection mode driving.

5, the backlight unit according to an exemplary embodiment of the present invention includes a power source unit 147, a light source unit 128a, a light source driver unit 145a, and a light source control unit 141. Referring to FIG.

The power source unit 147 receives the direct current input voltage Vin from the power supply unit and converts it into the direct current output voltage Vo to supply it to the light sources 128a. The light source 128a includes the first to Nth light emitting units D1 to Dn and the output voltage Vo output from the power supply unit 147 flows to the ground GND in accordance with the driving of the transistor Tf, It will come out.

The light source driver 145a generates a gate signal GC according to the light source driving signal SCD supplied from the light source controller 141 and outputs a current flowing between the drain terminal D and the source terminal S of the transistor Tf The gate signal GC is supplied to the gate terminal G so as to be controlled. Here, the transistor Tf may be formed of a field effect transistor (FET), but is not limited thereto. The light source driver 145a generates a feedback signal FB1 by comparing the voltage set internally and the voltage Vcurr flowing through the light source 128a and supplies the feedback signal FB1 to the power source 147. [ Accordingly, the power supply unit 147 can output a stable output voltage Vo by varying the output voltage Vo with respect to the input voltage Vin based on the feedback signal FB1. The light source driver 145a receives the sensing signal RB from the sensing resistor Rs formed between the source terminal S of the transistor Tf and the ground GND and supplies the sensing signal RB to the transistor Tf and the power source 147 The output voltage Vo can be controlled.

The light source control unit 141 generates a light source driving signal SCD for controlling the light source driving unit 145a and monitors at least one light source driving unit 145a to prevent the power source 147 from being overloaded . The light source control unit 141 performs monitoring through the drain terminal D of the transistor Tf and monitors at least one light source driving unit 145a when the power output from the power source unit 147 rises excessively ). The light source control unit 141 monitors the at least one light source driving unit 145a through the monitor unit 142 and performs at least one light source driving unit 145a in a protection mode Can be switched. For example, the light source control unit 141 may determine that the output power of the power source unit 147 has risen excessively if the monitored voltage is maintained for at least 2 seconds longer than 8V, but is not limited thereto.

In the case of the monitored voltage, the voltage is raised to a level higher than the voltage that the light source control unit 141 drives. The light source control unit 141 may include a voltage divider 143 composed of resistors R1 to R3 or the like so as to lower the level of the monitored voltage Vcurr through the drain terminal D of the transistor Tf. And an analog-to-digital converter 142a (A / D converter) for converting the analog voltage supplied through the voltage divider 143 into a digital signal to determine whether the output voltage of the power source 147 rises . According to such a configuration, the light source control unit 141 may determine whether the output power of the power source unit 147 rises within 3 V by dividing the excessively increased voltage, but is not limited thereto.

On the other hand, the light source control unit 141 controls the monitor unit 142 including the analog D / A converter 142a as well as the voltage divider 143 so that the transistor Tf is not driven when the output power of the power source unit 147 rises excessively do. Here, if it is determined that the output power of the power source unit 147 has risen excessively, the light source control unit 141 may turn off at least one light source driver 145a by omitting the output of the light source driving signal SCD . Also, the light source control unit 141 may transmit a signal indicating that the output power of the power source unit 147 has risen to other devices. As the light source driver 145a is turned off, the transistor Tf driven by the light source driver 145a is not yet supplied with the gate signal GC, so that the light source 128a is not driven. In order to suitably monitor the light source driving units, the light source control unit 141 may easily detect the voltage Vcurr flowing through the light source 128a of each channel through at least three light source driving units. This is because when the resistor Rs included in any one of the light source driving units is short, the voltage flowing through the light source driven by the remaining light source driving units rises, not the voltage flowing through the light source driven by the corresponding light source driving unit. Therefore, it is advantageous for the light source controller 141 to monitor a plurality of light source drivers in order to preferably monitor the light source drivers.

6, according to the above description, the light source control unit 141 controls the light source 128a in the normal state (NSATE), the short state (SSTATE), and the protection state (PSTATE) according to the voltage (Vcurr) Mode switching is possible. Here, the steady state (NSATE) indicates a state in which the normal voltage NV is being output when the light source control unit 141 monitors the voltage Vcurr flowing through the light source 128a. The shorted state (SSTATE) indicates a state in which an abnormal voltage (SV) is outputted due to a short circuit of the resistor Rs formed between the source terminal (S) of the transistor (Tf) and the ground (GND). The protection state PSTATE indicates a state where the light source control unit 141 turns off the at least one light source driver 145a and the omitted voltage (0V), that is, the transistor Tf is not yet driven.

As shown in FIG. 7, according to the above description, the backlight unit is driven to the power supply step S110, the light source driving step S113, the monitored voltage counting step S115, and the protection mode step S119.

The power supply step S110 is a step of supplying the output voltage Vo which is the power output from the power supply 147 to the light sources 128a including the light emitting units D1 to Dn.

The light source driving step S113 is a step of driving the light source driver 145a to drive the light sources 128a and providing light to the liquid crystal panel.

The monitored voltage counting step S115 is a step of monitoring at least one light source driver 145a by the light source controller 141. [ At this stage, the light source control unit 141 observes whether or not a voltage which is excessively increased for at least 2 seconds is inputted to determine whether the output power of the power source unit 147 has risen excessively. The reason for monitoring the voltage Vcurr flowing through the light source 128a for at least two seconds is to determine whether the output power of the power source unit 147 is due to a temporary error or a short circuit of the resistor Rs It is for the sake of clarity. In this step, when the voltage Vcurr flowing through the light source 128a is detected as a normal voltage or when the maximum voltage is outputted due to a temporary error, it is determined as a normal state (NSATE), so that the power supply step do. On the other hand, if the voltage Vcurr flowing through the light source 128a is detected as an abnormal voltage, it is judged as a short state (SSTATE), so the protection mode step S119 is performed.

The protection mode step S119 is a step for preventing an excessive rise of the power source output from the power source unit 147. [ At this stage, since the output power of the power source unit 147 has risen excessively, the light source control unit 141 switches to the protection state (PSTATE) in which at least one light source driver 145a is turned off. Then, at least one light source driver 145a enters a stop state in which the transistor Tf is not driven.

In the above description, the power supply 147 is excessively raised by the short circuit of the resistor Rs formed between the source terminal S of the transistor Tf and the ground GND. The short circuit of the resistor Rs can be short-circuited by factors (such as dust) occurring during the manufacturing process or during use. As described above, the output voltage Vo of the power supply 147 is controlled by the light source driver 145a. However, when the resistor Rs is short, the output voltage Vo of the power source 147 can not be easily controlled by the light source driver 145a, so that the voltage Vcurr flowing to the drain terminal D of the transistor Tf The voltage is increased to the maximum voltage. In this case, an overcurrent is generated by the load connected to the light source 128a and the transistor Tf associated with the power supply 147, and the circuits constituting the backlight unit due to the heat generation of the transistor Tf due to power loss are damaged, Can not be maintained. However, it is possible to solve the above problem by monitoring at least one light source driver 145a by using the light source controller 141 and preventing an excessive increase of the power outputted from the power source 147 as in the embodiment.

When the backlight unit having the above-described configuration is applied, the problem that the circuits constituting the backlight unit are damaged or can not be maintained due to the occurrence of a short circuit of the sensing resistor constituting the light source driving unit in manufacturing and driving the display device can be prevented .

The above-described backlight unit may be divided into an edge-type backlight unit, a dual-type backlight unit, a quad-type backlight unit, and a direct-type backlight unit according to the structure of the light source groups. The description thereof will be described in more detail below.

Fig. 8 is a view for explaining an edge type backlight unit, and Fig. 9 is a perspective view of a display device including an edge type backlight unit.

8, the edge-type backlight unit includes light sources 128 disposed on one side of the liquid crystal panel, a light guide plate 129 guiding the light generated from the light sources 128 to the liquid crystal panel, and a light guide plate 129 And an optical member 133 for efficiently supplying the light emitted from the liquid crystal panel to the liquid crystal panel. In the embodiment, the optical members 133 include a microlens sheet or the like, but the present invention is not limited thereto. The light sources 128 are examples in which the first to sixth light sources 128a to 128f are composed of two light source groups Gr1 and Gr2. Referring to FIG. 3, the first and second light source groups Gr1 and Gr2 of the embodiment may be driven by the first and second light source drivers 145a and 145b, respectively.

9, the display device includes a liquid crystal panel 126 and an edge-type backlight unit 130, which are positioned between the rear cover 151 and the front cover 152. The liquid crystal panel 126 includes a transistor substrate 126a and a color filter substrate 126b bonded together with a liquid crystal layer sandwiched therebetween. The data lines and the gate lines constituting the pixel array of the liquid crystal panel 126 are electrically connected to the printed circuit board 156 connected through the flexible film 155 to receive various driving signals.

The edge type backlight unit 130 of the embodiment includes light sources 128, a light guide plate 129, a reflector 135, and an optical member 133. The light sources 128 included in the edge type backlight unit 130 include the light emitting portions 127b disposed on the first side X1 with respect to the liquid crystal panel 126 and mounted on the substrate 127a. Here, the light sources 128 are mounted on at least one substrate. In the case of the edge type backlight unit 130, a bottom cover 154 for supporting the optical member 133 and the like may be included, but this may be omitted depending on the structure. In the edge-type backlight unit 130, the light incident through the light guide plate 129 is supplied to the liquid crystal panel 126 through the optical member 133. Here, the reflection plate 135 serves to reflect light such that the light incident on the light guide plate 129 in the lower portion of the light guide plate 129 is supplied toward the liquid crystal panel 126. The optical member 133 enhances the light output so that the light incident through the light guide plate 129 from the upper portion of the light guide plate 129 is efficiently supplied toward the liquid crystal panel 126.

The display device including the ideal edge type backlight unit 130 can display a specific image on the liquid crystal panel 126 using the light emitted from the light sources 128 disposed on the side X1 with respect to the liquid crystal panel 126 It becomes possible to display it.

FIG. 10 is a view for explaining a dual type backlight unit, and FIG. 11 is a perspective view of a display device including a dual type backlight unit.

10, the dual type backlight unit includes light sources 128 disposed opposite to the first and second sides of the liquid crystal panel, and a light guide plate (not shown) for guiding light generated from the light sources 128 to the liquid crystal panel And optical members 133 for efficiently supplying the light emitted from the light guide plate 129 and the liquid crystal panel. In the embodiment, the optical members 133 include a prism sheet or the like, but the present invention is not limited thereto. The light sources 128 are one example in which the first to twelfth light sources 128a to 128l are composed of four light source groups Gr1 to Gr4. Referring to FIG. 3, the first through fourth light source groups Gr1 through Gr4 of the embodiment may be driven by the first through fourth light source drivers 145a through 145d, respectively. On the other hand, the first to twelfth light sources 128a to 128l included in the four light source groups Gr1 to Gr4 constituting the dual type backlight unit are arranged such that the light sources arranged opposite to each other are, for example, 7 light source unit 128g and emits light in a pair.

11, the display device includes a liquid crystal panel 126 and a dual-type backlight unit 130, which are positioned between the back cover 151 and the front cover 152. As shown in FIG. The liquid crystal panel 126 includes a transistor substrate 126a and a color filter substrate 126b bonded together with a liquid crystal layer sandwiched therebetween. The data lines and the gate lines constituting the pixel array of the liquid crystal panel 126 are electrically connected to the printed circuit board 156 connected through the flexible film 155 to receive various driving signals.

The dual type backlight unit 130 of the embodiment includes light sources 128, a light guide plate 129, a reflector 135, and an optical member 133. The light sources 128 included in the dual type backlight unit 130 are disposed on the first side X1 and the second side X2 with respect to the liquid crystal panel 126 and the light emitting parts 127b. Here, the light sources 128 are mounted on at least two substrates. In the dual-type backlight unit 130, the light incident through the light guide plate 129 is supplied to the liquid crystal panel 126 through the optical member 133. Here, the reflection plate 135 serves to reflect light such that the light incident on the light guide plate 129 in the lower portion of the light guide plate 129 is supplied toward the liquid crystal panel 126. The optical member 133 enhances the light output so that the light incident through the light guide plate 129 from the upper portion of the light guide plate 129 is efficiently supplied toward the liquid crystal panel 126.

The display device including the dual type backlight unit 130 described above uses the light emitted from the light sources 128 disposed on the first side X1 and the second side X2 with respect to the liquid crystal panel 126 A specific image can be displayed on the liquid crystal panel 126.

FIG. 12 is a view for explaining a quad-type backlight unit, and FIG. 13 is a perspective view of a display device including a quad-type backlight unit.

12, the quad-type backlight unit includes light sources 128 disposed opposite to the first side, a second side, a third side and a fourth side with respect to the liquid crystal panel, and light generated from the light sources 128 A light guide plate 129 for guiding the light to the liquid crystal panel, and optical members 133 for effectively supplying the light emitted from the light guide plate 129 to the liquid crystal panel. In the embodiment, the optical members 133 include a prism sheet or the like, but the present invention is not limited thereto. The light sources 128 are examples in which the first to twentieth light sources 128a to 128t are composed of eight light source groups Gr1 to Gr8. Referring to FIG. 3, the first through eighth light source groups Gr1 through Gr8 of the embodiment may be driven by first through N-1th light source drivers 145a through 145n-1, respectively. On the other hand, the first to 20th light sources 128a to 128t included in the eight light source groups Gr1 to Gr8 constituting the quad-type backlight unit are arranged such that the light sources arranged opposite to each other are, for example, the first light source unit 128a and the seventh The light source units 128g emit light in a pair, and the sixteenth light source unit 128m and the twentieth light source unit 128q form a pair and emit light.

13, the display device includes a liquid crystal panel 126 and a quad-type backlight unit 130, which are positioned between a rear cover 151 and a front cover 152. The liquid crystal panel 126 includes a transistor substrate 126a and a color filter substrate 126b bonded together with a liquid crystal layer sandwiched therebetween. The data lines and the gate lines constituting the pixel array of the liquid crystal panel 126 are electrically connected to the printed circuit board 156 connected through the flexible film 155 to receive various driving signals.

The quad-type backlight unit 130 of the embodiment includes the light sources 128, the light guide plate 129, the reflector 135, and the optical member 133. The light sources 128 included in the quad-type backlight unit 130 are disposed on the first side X1, the second side X2, the third side Y1 and the fourth side Y2 with respect to the liquid crystal panel 126 And light emitting portions 127b disposed on the substrate 127a. Here, the light sources 128 are mounted on at least four substrates. In the quad-type backlight unit 130, the light incident through the light guide plate 129 is supplied to the liquid crystal panel 126 through the optical member 133. Here, the reflection plate 135 serves to reflect light such that the light incident on the light guide plate 129 in the lower portion of the light guide plate 129 is supplied toward the liquid crystal panel 126. The optical member 133 enhances the light output so that the light incident through the light guide plate 129 from the upper portion of the light guide plate 129 is efficiently supplied toward the liquid crystal panel 126.

The display device including the ideal quad-type backlight unit 130 is disposed on the first side X1, the second side X2, the third side Y1 and the fourth side Y2 with respect to the liquid crystal panel 126 It is possible to display a specific image on the liquid crystal panel 126 using the light emitted from the light sources 128.

FIG. 14 is a view for explaining a direct-type backlight unit, and FIG. 15 is a perspective view of a display device including a direct-type backlight unit.

14, the direct-type backlight unit includes light sources 128 arranged on a lower block with respect to the liquid crystal panel and light guide plates 129 guiding the light generated from the light sources 128 to the liquid crystal panel And optical members 133 for efficiently supplying the light emitted from the light guide plates 129 to the liquid crystal panel. In the case of the direct-type backlight unit of the embodiment, the first through 24th light guide plates 129a through 129x included in the respective light sources 128 are formed in a wedge shape, and reflection plates 135a , 135i and 135q, respectively. The first through 24th light guide plates 129a through 129x having wedge shapes are formed in a part of the first, ninth, and seventeenth light guide plates 129a, 129i, and 129q, for example, first, Are disposed so as to overlap with the region where the seventeenth light sources 128a, 128i, 128q are located. The direct-type backlight unit of the embodiment can prevent optical interference between the first to 24th light sources 128a to 128x arranged in the vertical direction and the left and right direction according to the thus structured feature. The light sources 128 are examples in which the first to 24th light sources 128a to 128x are composed of twelve light source groups Gr1 to Gr12. Referring to FIG. 3, the first to twelfth light source groups Gr1 to Gr12 of the embodiment may be driven by the first to Nth light source drivers 145a to 145n, respectively. On the other hand, the first to 24th light sources 128a to 128x included in the twelve light source groups Gr1 to Gr12 constituting the direct-type backlight unit individually emit light sources arranged opposite to each other.

15, the display device includes a liquid crystal panel 126 and a direct-type backlight unit 130, which are positioned between a rear cover 151 and a front cover 152. [ The liquid crystal panel 126 includes a transistor substrate 126a and a color filter substrate 126b bonded together with a liquid crystal layer sandwiched therebetween. The data lines and the gate lines constituting the pixel array of the liquid crystal panel 126 are electrically connected to the printed circuit board 156 connected through the flexible film 155 to receive various driving signals.

The direct type backlight unit 130 of the embodiment includes light sources 128, a light guide plate 129, a reflector 135, and an optical member 133. The light sources 128 included in the direct type backlight unit 130 include light emitting units 127b disposed on the lower side of the liquid crystal panel 126 in block units and mounted on the light source substrate 127a. In the case of the direct-type backlight unit 130, a plurality of light guide plates 129 and a reflection plate 135 are divided and arranged so as to correspond to the block units of the light sources 128. In the direct-type backlight unit 130, the light incident through the light guide plate 129 is supplied to the liquid crystal panel 126 through the optical member 133. Here, the reflection plates 135 serve to cause light reflection or the like so that light incident on the light guide plate 129 at the lower portion of the light guide plate 129 is supplied toward the liquid crystal panel 126. The optical member 133 enhances the light output so that the light incident through the light guide plate 129 from the upper portion of the light guide plate 129 is efficiently supplied toward the liquid crystal panel 126. Here, in the case of the direct-type backlight unit 130, a transparent reflector 136 covering all of the light sources 128 arranged in units of blocks may be further included.

The display device including the direct lower backlight unit 130 can display a specific image on the liquid crystal panel 126 using the light emitted from the light sources 128 arranged on the lower side of the liquid crystal panel 126 in block units It becomes possible to display it.

As described above, in the fabrication and operation of a display device, even if a problem such as a short circuit occurs in a sensing resistor constituting a light source driving unit including a backlight unit, damage to circuits constituting the backlight unit is prevented to protect the device In addition, there is an effect of providing a display device capable of maintaining reliability.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

141: Light source control unit 145: Light source driving unit
128: Light sources 147: Power source
121: timing control unit 123:
124: gate driver 126: liquid crystal panel
130: backlight unit 142: monitor unit

Claims (14)

A power supply unit;
A light source including light emitting units receiving power from the power source unit and providing light to the panel;
Light source drivers including a transistor driving the light sources and electrically connected to at least one of the light sources, and a resistor electrically connected to the transistor; And
And a light source control unit for driving the light source driving units and sensing a voltage of at least one of the light source driving units to prevent a voltage output from the power source unit from becoming higher than a voltage of a normal state,
The light source control unit,
Wherein at least one light source driver is not driven when at least one of the light source drivers detects a voltage greater than a steady state voltage for at least two seconds. The method according to claim 1,
The light source control unit,
And a monitor unit for sensing the voltage through a drain terminal of the transistor and for inactivating at least one light source driving unit when a voltage greater than a voltage of the steady state is detected from the power supply unit. delete The method according to claim 1,
The light source control unit,
And the transistor is not driven if an output voltage of the power supply unit is greater than a voltage of the steady state. The method according to claim 1,
Wherein an output voltage of the power supply unit is greater than a voltage of the steady state by a short circuit of the resistor. The method according to claim 1,
The light source control unit,
Wherein the controller determines that the output voltage of the power supply unit is greater than the steady state voltage when the sensed voltage is maintained for at least 2 seconds longer than 8V. The method according to claim 1,
The light source control unit,
A voltage divider for lowering the level of the voltage sensed through the drain terminal of the transistor;
And an analog-to-digital converter for determining whether an output voltage of the power supply unit is higher than a voltage of the steady state by a voltage supplied through the voltage divider. Claim 8 has been abandoned due to the setting registration fee. A power supply unit;
A light source including light emitting units receiving power from the power source unit and emitting light;
Light source drivers including a transistor driving the light sources and electrically connected to at least one of the light sources, and a resistor electrically connected to the transistor; And
And a light source control unit for driving the light source driving units and sensing a voltage of at least one of the light source driving units to prevent a voltage output from the power source unit from becoming higher than a voltage of a normal state,
The light source control unit,
Wherein the at least one light source driving unit is not driven when at least one of the light source driving units detects a voltage greater than a steady state voltage for at least two seconds. Claim 9 has been abandoned due to the setting registration fee. 9. The method of claim 8,
The sensing of the voltage,
And the drain terminal of the transistor is connected to the drain terminal of the transistor. delete Claim 11 has been abandoned due to the set registration fee. 9. The method of claim 8,
The light source control unit,
Wherein when the output voltage of the power source unit is greater than the voltage of the steady state, the transistor included in the light source driver units is not driven. Claim 12 is abandoned in setting registration fee. 9. The method of claim 8,
Wherein an output voltage of the power supply unit is greater than a voltage of the steady state by a short circuit of the resistor included in the light source driving units. Claim 13 has been abandoned due to the set registration fee. 9. The method of claim 8,
The light source control unit,
Wherein the controller determines that the output voltage of the power supply unit is greater than the steady state voltage when the sensed voltage is maintained for at least 2 seconds longer than 8V. Claim 14 has been abandoned due to the setting registration fee. 9. The method of claim 8,
The light source control unit,
A voltage divider for lowering the level of the voltage sensed through the drain terminal of the transistor;
And an analog-to-digital converter for determining whether the output voltage of the power supply unit is higher than the voltage of the steady state by a voltage supplied through the voltage divider.

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