Patent Publication Number: US-8531125-B2

Title: Backlight assembly, and display apparatus and television comprising the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. 10-2009-0093237, filed on Sep. 30, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     Aspects of the present inventive concept relate to a backlight assembly, and a display apparatus and a television comprising the same, and more particularly, to a backlight assembly, and a display apparatus and a television comprising the same which includes a light emitting diode (LED). 
     2. Description of the Related Art 
     In recent years, flat display devices, such as a liquid crystal display (LCD), a plasma display panel (PDP) and an organic light emitting diode (OLED), have increasingly replaced cathode ray tubes (CRT). 
     As a liquid crystal panel of the LCD does not emit light itself, the LCD has a backlight unit in a rear side thereof to receive light. Transmittance of light that is emitted by the backlight unit is adjusted by arrangement of liquid crystals. The liquid crystal display panel and the backlight unit are accommodated in an accommodating member, such as a chassis. A light source which is used in the backlight unit may include a linear light source, such as a lamp, and a point light source, such as a light emitting diode (LED). Among them, the LED has drawn a lot of attention recently. 
     A power driver, which changes a state of input power and supplies the power to the light source, is normally divided into several blocks. In accordance with the upsizing of the display apparatus, the number of light sources included in the backlight unit increases as well as the number of power drivers. As a result, the configuration of the display apparatus becomes complicated. 
     SUMMARY 
     Accordingly, aspects of the present inventive concept provide a backlight assembly, and a display apparatus and a television comprising the same which is more efficient and slimmer. Also, aspects of the present inventive concept provide a backlight assembly, and a display apparatus and a television comprising the same which has a simple control configuration. Further, aspects of the present inventive concept provide a backlight assembly, and a display apparatus and a television comprising the same which reduces manufacturing costs by decreasing the number of components used. 
     Additional aspects and/or advantages of the present inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present inventive concept. 
     According to an aspect of the present inventive concept, there is provided a backlight assembly including: a power unit which outputs a current whose polarity is changed on a regular basis; a plurality of balancing units which is connected in parallel to the power unit; a plurality of light emitting diode (LED) modules each of which individually receive the respective current output by a corresponding balancing unit of the plurality of balancing units; and a driver which is connected between the plurality of balancing units and the plurality of LED modules, and which forms a current route for each of the plurality of balancing units to balance the current supplied to two different LED modules during a single period where the polarity of the current output by the power unit is changed. 
     The current which is supplied to the plurality of LED modules may be equally balanced during the single period where the polarity of the current output by the power unit is changed. 
     The power unit may include: a power factor compensator which compensates for a power factor of primitive power; an inverter which converts a direct current whose power factor is compensated for by the power factor compensator into an alternating current; and a transformer which transforms the alternating current as a primary current into a secondary current. 
     The plurality of balancing units may each include a balancing capacitor which is connected to at least one end of a secondary coil included in the transformer. 
     The driver may include: a first diode line which forms a first current route supplying a current output by a first end of the transformer to a first LED module if the current output by the power unit is positive; and a second diode line which forms a second current route supplying a current output by a second end of the transformer to a second LED module if the current output by the power unit is negative. 
     The inverter may include a half bridge type or a full bridge type. 
     The plurality of balancing units may be connected in parallel to a single secondary coil included in the transformer. 
     The plurality of balancing units may be connected to a plurality of secondary coils included in the transformer. 
     The backlight assembly may further include a driving controller which detects the current flowing in the plurality of LED modules, and generates a control signal to control the detected current to become a predetermined reference current and outputs the control signal to the power unit. 
     The driving controller may perform a variable frequency control or a fixed frequency control. 
     According to another aspect of the present inventive concept, there is provided a display apparatus including: a liquid crystal display (LCD) panel which displays an image thereon; and a backlight assembly which emits light to the LCD panel, the backlight assembly including: a power unit which outputs a current whose polarity is changed on a regular basis; a plurality of balancing units which is connected in parallel to the power unit; a plurality of LED modules each of which individually receives the current output by a corresponding balancing unit of the plurality of balancing units; and a driver which is connected between the plurality of balancing units and the plurality of LED modules, and forms a current route for each balancing unit to balance a current supplied to two different LED modules during a single period where the polarity of the current output by the power unit is changed. 
     The current supplied to the plurality of LED modules may be equally balanced during the single period where the polarity of the current output by the power unit is changed. 
     The power unit may include: a power factor compensator which compensates for a power factor of primitive power; an inverter which converts a direct current whose power factor is compensated for by the power factor compensator into an alternating current; a transformer which transforms the alternating current as a primary current into a secondary current; and the plurality of balancing units may each include a balancing capacitor which is connected to at least a first end of a secondary coil included in the transformer. 
     The driver may include: a first diode line which forms a first current route supplying a current output by a first end of the transformer to a first LED module if the current output by the power unit is positive; and a second diode line which forms a second current route supplying a current output by a second end of the transformer to a second LED module if the current output by the power unit is negative. 
     According to another aspect of the present inventive concept, there is provided a television, including: a broadcasting receiver which receives a broadcasting signal; a signal processor which processes the received broadcasting signal; a liquid crystal display (LCD) panel which displays the processed broadcasting signal thereon; a backlight assembly which emits light to the LCD panel, the backlight assembly including: a power unit which outputs a current whose polarity is changed on a regular basis; a plurality of balancing units which is connected in parallel to the power unit; a plurality of light emitting diode (LED) modules each of which individually receive the current output by a corresponding balancing unit of the plurality of balancing units; and a driver which is connected between the plurality of balancing units and the plurality of LED modules, and forms a current route for each balancing unit to balance a current supplied to two different LED modules during a single period where a polarity of the current output by the power unit is changed. 
     The current supplied to the plurality of LED modules may be equally balanced during the single period where the polarity of the current output by the power unit is changed. 
     The power unit may include: a power factor compensator which compensates for a power factor of primitive power; an inverter which converts a direct current whose power factor is compensated for by the power factor compensator into an alternating current; and an insulating transformer which transforms the alternating current as a primary current into a secondary current. 
     The plurality of balancing units may each include a balancing capacitor which is connected to at least a first end of a secondary coil included in the insulating transformer. 
     The driver may include: a first diode line which forms a first current route supplying a current output by a first end of the transformer to a first LED module if the current output by the power unit is positive; and a second diode line which forms a second current route supplying a current output by a second end of the insulating transformer to a second LED module if the current output by the power unit is negative. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and/or other aspects of the present inventive concept will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a control block diagram of a backlight assembly according to an exemplary embodiment of the present inventive concept; 
         FIG. 2  is a circuit diagram of the backlight assembly in  FIG. 1 ; 
         FIG. 3  illustrates a current route in accordance with the circuit diagram in  FIG. 2 ; 
         FIG. 4  illustrates another current route in accordance with the circuit diagram in  FIG. 2 ; 
         FIG. 5  is a circuit diagram of a backlight assembly according to another exemplary embodiment of the present inventive concept; 
         FIG. 6  is a circuit diagram of a backlight assembly according to another exemplary embodiment of the present inventive concept; 
         FIG. 7  is a circuit diagram of a backlight assembly according to another exemplary embodiment of the present inventive concept; 
         FIG. 8  is a control block diagram of a display apparatus according to an exemplary embodiment of the present inventive concept; and 
         FIG. 9  is a control block diagram of a television according to an exemplary embodiment of the present inventive concept. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, exemplary embodiments of the present inventive concept will be described with reference to accompanying drawings, wherein like numerals refer to like elements and repetitive descriptions will be avoided as necessary. 
       FIG. 1  is a control block diagram of a backlight assembly according to an exemplary embodiment of the present inventive concept.  FIG. 2  is a circuit diagram of the backlight assembly in  FIG. 1 . As shown therein, the backlight assembly includes a power unit  100 , a plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260 , a plurality of light emitting diode (LED) modules  410 ,  420 ,  430 ,  440 ,  450  and  460  corresponding to the number of the plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260 , a driver  300  to drive the plurality of LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 , and a driving controller  500  to control a current supplied to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . 
     The power unit  100  outputs a current whose polarity is changed on a regular basis. That is, the power unit  100  outputs a sine wave or square wave current, whose polarity is changed from positive to negative and vice versa, to the plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260 . The power unit  100  according to the present exemplary embodiment includes a power factor compensator  110 , an inverter  120 , and a transformer  130  which is connected to the inverter  120 . 
     The power factor compensator  110  converts primitive power (i.e., input commercial AC power) into DC power, and compensates for a power factor of the converted DC power. The power factor compensator  110  may include a rectifying circuit to convert AC power into DC power. DC power which is output by the power factor compensator  110  may present a voltage level ranging from 200V to 400V.  FIG. 2  illustrates power which is output by the power factor compensator  110 . If a voltage level of primitive power is below approximately 75V, the power factor compensator  110  may be omitted. That is, the power factor compensator  110  may be omitted depending on the voltage level of the primitive power and product standards. 
     The inverter  120  includes a plurality of switching elements S 1  and S 2  and resonance circuits C and L which convert input DC current into AC current. The inverter  120  is a half bridge which includes a first switching element S 1  and a second switching element S 2 . Polarity of the current input to the transformer  130  is changed to the opposite when the first switching element S 1  is turned on and the second switching element S 2  is turned off and when the first switching element S 1  is turned off and the second switching element S 2  is turned on. 
     The transformer  130  converts a primary current output by the inverter  120  (i.e., an alternating current) into a secondary current. The transformer  130  may include an insulating transformer or a non-insulating transformer. If the transformer  130  includes an insulating transformer, the transformer  130  may protect the circuit from high voltage or high current generated by a ground loop or a line surge and stably drive the backlight assembly. The transformer  130  includes a plurality of secondary coil  132 , and each of the secondary coils  132  is respectively connected to corresponding balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260 . The number of turns of the plurality of secondary coils  132  may be equal to thereby substantially induct the same current into the balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260 . A winding ratio of the primary coils  131  and the secondary coils  132  of the transformer  130  (i.e., the ratio of coils) is n 1 :n 2 , and the current which is inducted into the secondary coils  132  is adjusted to different levels according to the ratio of coils. 
     The plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260  is connected in parallel to the power unit  100 , and more specifically, to the plurality of secondary coils  132  of the transformer  130 . The balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260  include balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  which are connected to at least a first end of the secondary coils  132 . The balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  may additionally be connected to a second end of the secondary coils  132 . The balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260  balance a current supplied to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  and adjust a current to be supplied equally to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . 
     The plurality of LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  individually receive a current output by the plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260 . That is, the plurality of LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  may correspond to the plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260  in a one-to-one ratio. The LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  include a plurality of LEDs and power supply is controlled by unit of the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . 
     The driver  300  is connected between the plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260  and the plurality of LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 , and forms a current route for the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  included in the plurality of balancing units  210 ,  220 ,  230 ,  240 ,  240 ,  250  and  260  to balance a current supplied to two different LED modules during a single period where a polarity of the current output by the power unit  100  is changed. The detailed configuration of the driver  300  will be described later. 
     The driving controller  500  generates a control signal to control a current flowing in the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  to be a preset reference current based on a fed-back current flowing in the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . As shown, a gate signal  1  and a gate signal  2  are output by the driving controller  500  to the switching elements S 1  and S 2  of the power unit  100 . A reference current corresponds to a brightness of the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 , and may be set and changed by a user. The driving controller  500  may output a control signal through a variable frequency control or a fixed frequency control. A control method of the driving controller  500  may include any of various methods known in the art. 
     Typically, a power driver, which supplies driving power to a light source of the backlight assembly, includes several blocks. For example, the power driver may be classified into a block which converts AC power into DC power, a converter block which converts DC power into a voltage at a consistent level and a light source driver block which adjusts a consistent voltage and supplies a current at a consistent level to the light source. In this case, input power should go through the three blocks to be finally supplied to the light source unit, and the nature of the power is changed while going through each block. Efficiency decreases when the power goes through a single block and the final efficiency of power which has gone through three blocks is approximately 73% even if power efficiency for each block is 90%. That is, as at least 27% is consumed as heat, and there arises a problem due to the heat. As the number of light sources increase, blocks which supply driving power also increase, thereby adversely affecting downsizing of the backlight assembly. 
     According to the present exemplary embodiment, power which is output by the power factor compensator  110  is controlled by only the driving controller  500 . Elements which are included in the inverter  120  and the driver  300  are passive elements and do not require an additional control. That is, the backlight assembly includes a first block which includes the power factor compensator  110  and a second block which includes a power conversion block and a light source driver block, rather than three power blocks which need three controls. Reduction of control circuits results in simplified control, increased efficiency in driving, and reduced manufacturing costs. The heating problem of the backlight assembly is improved and the backlight assembly is downsized by the reduced power blocks. 
     The driver  300  includes a rectifying capacitor CR which is connected in parallel to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  and a sub driver which includes four diodes D 1 , D 2 , D 3  and D 4 . As shown therein, the sub driver is connected to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  and symmetrical to each other. The first diode D 1  is connected between the balancing capacitor CB 1  and the rectifying capacitor CR. The second diode D 2  is connected between the ground and a second end of the secondary coils  132 . The third diode D 3  is connected between a node of the balancing capacitor CB 1  and the first diode D 1  and the ground, and the fourth diode D 4  is connected between a node and an output terminal of the first diode D 1  included in the adjacent sub driver, the node being between the second end of the secondary coils  132  and the second diode D 2 . The first diode D 1 , the rectifying capacitor CR and the second diode D 2  form a first current route while the fourth diode D 4 , the rectifying capacitor CR and the third diode D 3  form a second current route. 
       FIG. 3  illustrates the first current route which is formed when a positive current is output by the power unit  100 . If the first switching element S 1  of the inverter  120  is turned on and if the second switching element S 2  is turned off, a direct current which is input to both ends of the inverter  120  becomes a high level and a positive current flows clockwise after going through the capacitor C and the inductor L. The current is inducted into the secondary coils  132  by the transformer  130 , and supplied to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  through the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  and the first diode D 1 . The rectifying capacitor CR reduces an AC component from the current. Thus, the current becomes DC power at a consistent level whose ripple has been removed. The LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  emit light in proportion to the current applied. Currents iCB 1 , iCB 2 , iCB 3 , iCB 4 , iCB 5  and iCB 6  which have gone through the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  are transmitted to the secondary coils  132  through the second diode D 2 . In sum, when a positive current is output by the power unit  100 , the first current loop is formed by the secondary coils  132 , the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6 , the first diode D 1 , the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 , the second diode D 2 , and the secondary coils  132 . An average current iCB 1  which flows in the first balancing capacitor CB 1  becomes a current Iled 1  flowing in the first LED module  410 , and an average current iCB 2  which flows in a second balancing capacitor CB 2  becomes a current Iled 2  flowing in the second LED module  420 , and an average current which flows in an Nth balancing capacitor becomes a current flowing in an Nth LED module. 
       FIG. 4  illustrates the second current route which is formed when a negative current is output by the power unit  100 . If the first switching element S 1  of the inverter  120  is turned off and if the second switching element S 2  is turned on, a direct current which is input to both ends of the inverter  120  becomes a low level and a negative current flows counterclockwise after going through the inductor L and the capacitor C. The current is inducted into the secondary coils  132  by the transformer  130 , and supplied to the adjacent LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  provided in a lower end through the fourth diode D 4 . Currents iCB 1 , iCB 2 , iCB 3 , iCB 4 , iCB 5  and iCB 6  which have gone through the adjacent LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  are transmitted back to the secondary coils  132  through the third diode D 3  and the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6 . In sum, when a negative current is output by the power unit  100 , the second current loop is formed by the secondary coils  132 , the fourth diode D 4 , the adjacent LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 , the third diode D 3 , the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  and the secondary coils  132 . An average current iCB 1  which flows in the first balancing capacitor CB 1  becomes a current Iled 2  flowing in the second LED module  420 , and an average current iCB 2  which flows in the second balancing capacitor CB 2  becomes a current Iled 3  flowing in the third LED module  430 , and an average current iCBN which flows in an Nth balancing capacitor  460  becomes a current Iled 1  flowing in the first LED module  410 . 
     If a sine wave current is input to the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6 , an average current iCB 1 , iCB 2 , iCB 3 , iCB 4 , iCB 5  and iCB 6  flowing in the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  during a single period becomes zero by charge and discharge of the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6 . When the average current iCB 1  becomes zero during a single period, the current Iled 1  flowing in the first LED module  410  is the same as a current Iled 2  flowing in the second LED module  420 . Likewise, the current Iled 2  flowing in the second LED module  420  becomes equal to the current Iled 3  flowing in the third LED module  430  during a single period since the average current iCB 2  flowing in the second capacitor CB 2  becomes zero during a single period. Similarly, the current Iled 6  flowing in the sixth LED module  460  becomes equal to the current Iled 1  flowing in the first LED module  410  during a single period by the sixth balancing capacitor CB 6  connected lastly. As a result, the currents which flow in all of the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  during a single period are balanced equally. 
     To equally balance the current flowing in the N number of LED modules, the driver  300  includes the N number of balancing capacitors. Furthermore, a current route is formed to have the current flow in each half from the balancing capacitors to the two LED modules  410  and  420 ,  420  and  430 ,  430  and  440 ,  440  and  450 ,  450  and  460 , and  460  and  410 . Since the current balancing of the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  may be accomplished by only the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6 , power efficiency of driving the LED modules CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  may be improved, and the overall size of the backlight assembly and the manufacturing costs may be reduced. 
     The current balancing which uses the sine curve may balance the current flowing in the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  regardless of an impedance of the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  and the diodes D 1 , D 2 , D 3  and D 4  and an impedance of the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . 
       FIG. 5  is a circuit diagram of a backlight assembly according to another exemplary embodiment of the present inventive concept. Referring to  FIG. 5 , the driver  300  further includes a fifth switching element S 5  which applies a pulse width modulation (PWM) dimming signal to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . The PWM dimming signal which is applied to the fifth switching element S 5  is the same as a PWM dimming signal input to the driving controller  500 . If power supplied to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  should be cut off (i.e., if the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  should be turned off), the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  may not be immediately turned off due to a delay time where the PWM dimming signal is transmitted to the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . Likewise, turn-on timing of the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  may also be delayed. Accordingly, to turn on and off the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  quickly and accurately, the PWM dimming signal is also applied to a first end of the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460 . 
       FIG. 6  is a circuit diagram of a backlight assembly according to another exemplary embodiment of the present inventive concept. Referring to  FIG. 6 , the transformer includes primary coils  131  and a secondary coil  133 . The plurality of balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  is connected in parallel to the secondary coil  133 . The current route of the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6  and the LED modules  410 ,  420 ,  430 ,  440 ,  450  and  460  may be easily recognized by one of ordinary skill in the art, and a repetitive description thereof is omitted herein. 
     It is understood that the relationship between the secondary coil  132  and  133  and the primary coil  131  is not limited in all aspects of the present inventive concept to those shown in  FIGS. 2 and 6 , and may vary as long as the coils induct a current into the balancing capacitors CB 1 , CB 2 , CB 3 , CB 4 , CB 5  and CB 6 . 
       FIG. 7  is a circuit diagram of a backlight assembly according to another exemplary embodiment of the present inventive concept. Referring to  FIG. 7 , the inverter  121  includes a full bridge rather than a half bridge. The full bridge type includes four switching elements S 1 , S 2 , S 3  and S 4 . The inverter  121  may include a resonance circuit which includes a capacitor C and an inductor L. The inverter  121  is not limited to that shown in the drawings and may include various known circuits. 
       FIG. 8  is a control block diagram of a display apparatus according to an exemplary embodiment of the present inventive concept. Referring to  FIG. 8 , the display apparatus includes a backlight assembly  1000  and a liquid crystal display (LCD) panel  2000 . The display apparatus may include any of the backlight assemblies shown in  FIGS. 2 to 7 . 
     The backlight assembly  1000  is disposed in a rear surface of the LCD panel  2000  and emits light to the LCD panel  2000 . Since the backlight assembly  1000  includes an LED module as a point light source, the backlight assembly  1000  may perform scanning driving by applying a PWM control signal to each of the LED modules, and may perform a local dimming by arranging the LED modules corresponding to a particular area of the LCD panel  2000 . That is, a brightness control which considers an image signal displayed on the LCD panel  2000  is available. The backlight assembly  1000  according to the exemplary embodiment has simpler hardware and control configuration and contributes to downsizing the display apparatus. 
     If the display apparatus includes a monitor which is connected to a computer system, the display apparatus may not include a power factor compensator  110  in the power unit  100  of the backlight assembly  1000 . If an adaptor which is connected to a commercial AC power terminal is used to supply power to the monitor, the power factor compensator  110  may be included in the adaptor rather than the monitor. 
       FIG. 9  is a control block diagram of a television (TV) according to an exemplary embodiment of the present inventive concept. Referring to  FIG. 9 , the TV further includes a broadcasting receiver  3000  and a signal processor  4000 . 
     The broadcasting receiver  3000  tunes a channel frequency and receives a broadcasting signal from the channel. The broadcasting receiver  3000  includes a channel detection module (not shown) and an RF demodulation module (not shown). 
     The signal processor  4000  processes a broadcasting signal received from the broadcasting receiver  3000  and displays the broadcasting signal on the LCD panel. The signal processor  4000  includes a demultiplexer (not shown), a video decoder (not shown), and an audio decoder (not shown). A current which is output by the power unit  100  may be supplied to the broadcasting receiver  3000  and the signal processor  4000 . The power unit  100  may further include a power converter (not shown) which converts a current output by the power factor compensator  110  to a power level necessary for the signal processor  4000  which processes the broadcasting signal. 
     The TV should be insulated from a commercial AC power terminal to secure electric safety. According to the present exemplary embodiment, the power unit  100  includes an insulating transformer  130 ′ whose primary end and a secondary end are insulated from each other. If the insulation configuration is not required, the transformer may not include an insulating transformer  130 ′ or an insulation configuration may apply to components other rather than the transformer. Like the display apparatus, the backlight assembly may supply light, which is partially different in brightness or color, to the LCD panel  2000  displaying a broadcasting signal thereon. 
     As described above, according to aspects of the present inventive concept, a backlight assembly, and a display apparatus and a television comprising the same are more efficient and slimmer. Also, according to aspects of the present inventive concept, a backlight assembly, and a display apparatus and a television comprising the same have a simple control configuration. Further, according to aspects of the present inventive concept, a backlight assembly, and a display apparatus and a television comprising the same reduce manufacturing costs by decreasing the number of components used. 
     Although a few exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.