KR20090058380A

KR20090058380A - Liquid crystal display device

Info

Publication number: KR20090058380A
Application number: KR1020070125128A
Authority: KR
Inventors: 정규봉
Original assignee: 엘지디스플레이 주식회사
Priority date: 2007-12-04
Filing date: 2007-12-04
Publication date: 2009-06-09

Abstract

The present invention provides a hybrid direct type liquid crystal display device having a plurality of fluorescent lamps such as EEFL and an LED light emitting means at an edge thereof, wherein the LED light emitting means is generated between the fluorescent lamp and the lower cover with the fluorescent lamp. As related to a liquid crystal display device to be driven using a leakage current, the liquid crystal display device according to the first embodiment includes a bottom cover having a bottom frame and sidewalls extending from at least one edge of the bottom frame; A plurality of first light emitting means arranged and arranged at regular intervals on the lower cover, the first light emitting means being disposed in parallel with the sidewalls; PCBs provided at both sides of the lower cover to fasten the first light emitting means and to receive a voltage from the outside; A conductive member disposed on the lower cover in parallel with the PCB and detecting a leakage current of the first light emitting means by a first conductive electrode formed on a guide holder to which the first light emitting means is fastened; And a second conductive electrode and a third conductive electrode which are provided at at least one side of the first light emitting means disposed at the outermost part of the lower cover, and electrically connected to the conductive member and the lower cover, respectively, on both sides thereof. And a second light emitting means driven by the detected leakage current.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a hybrid direct type liquid crystal display device having a plurality of fluorescent lamps such as EEFL and additionally having LED light emitting means at an edge thereof, A liquid crystal display device is intended to be driven by a leakage current generated between a fluorescent lamp and a lower cover provided with the fluorescent lamp.

CRT (Cathode Ray Tube), one of the widely used display devices, is mainly used for monitors such as TVs, measuring devices, and information terminal devices.However, due to the weight and size of the CRT itself, the miniaturization and weight reduction of electronic products Could not actively respond to the response.

For this reason, liquid crystal display devices having advantages of small size, light weight, and low power consumption have been actively developed to replace CRTs, and nowadays, the liquid crystal display devices have been sufficiently developed to perform a role as flat panel display devices. The demand is increasing gradually to the large-screen outdoor monitors and wall-mounted TVs.

A liquid crystal display device is a light receiving device that displays an image by controlling the amount of light coming from the outside. For this reason, a separate light source, that is, a backlight device, for irradiating light to an LCD panel (Liquid Crystal Display Panel) is required. Usually, it is classified into edge type and direct type according to the position of the light source with respect to the display surface. Among them, the direct type backlight device has high light utilization, simple handling, and limited display size. It is widely used in a large liquid crystal display device of 30 inches or more because it is not present.

Hereinafter, a general direct type liquid crystal display device will be described with reference to the drawings.

1 is an exploded perspective view of a general liquid crystal display device.

As shown in FIG. 1, a general liquid crystal display device is made of synthetic resin or stainless steel and has an image on the upper side of the main support 49 which maintains the balance of the overall force of the liquid crystal display device. The liquid crystal panel 50 is loaded, and a backlight device is provided below the liquid crystal panel 50 to provide light to the liquid crystal panel 50. Here, the backlight device is composed of a lamp 43 that is a light source and an optical member 47 that complements the optical characteristics of the light provided from the lamp 43.

First, a reflector 41 is attached on the lower cover 40 to reflect light from the plurality of lamps 43 as light sources to the front.

In addition, a lamp guide 42 is provided in the center area on the lower cover 40 to prevent bending of the lamp 43 which is subsequently fastened and to prevent sagging of the optical sheet 47 loaded on the upper side of the lamp 43. .

In addition, both sides of the lower cover 40 is provided with a lamp holder (not shown) for protecting the electrode portion of the lamp 43, the plurality of lamps 43 including the lamp holder therein is fixed and arranged The side support 45 is provided.

The diffuser plate 47a is configured to uniformly disperse the light directly reflected from the lamps 43 and the light reflected through the reflecting plate 41 on the upper side of the lower cover 40 having the lamps 43 arranged thereon. Optical sheets 47b and 47c including are stacked.

Subsequently, the main support 49 is fastened to maintain the balance of the overall force of the liquid crystal display. In this case, a pattern having a step is formed on the upper surface of the main support 49 in consideration of the liquid crystal panel 50 being loaded on the front surface.

In addition, the liquid crystal panel 50 is mounted on the main support 49. The liquid crystal panel 50 is a crystal formed by many unit processes. In other words, it comprises an array substrate on which thin film transistors are arranged as switching elements for each unit pixel, a color filter substrate on which a color filter representing color is correspondingly formed, and a liquid crystal injected between the two substrates.

The upper cover 60 surrounding the outer side of the upper liquid crystal panel 50 and the main support 49 is fastened to the lower cover 40 through a separate hook.

In addition, in order to drive the plurality of lamps 43 provided on the lower cover 40 of the liquid crystal display device, a high voltage is applied to both sides of the lamp 43 from the outside in a high-high type, respectively. Lamp driving circuit (not shown) for applying the additional is provided.

However, in the direct type liquid crystal display device as described above, a parasitic capacitance is generated between the lower cover and a lamp provided on the lower cover to generate a leakage current, which is disposed at the outermost portion of the lower cover and the lower cover. The leakage current generated by the parasitic capacitance between the lamps is particularly increased than the leakage current in other areas.

In other words, the outermost lamps arranged on the lower cover and arranged at the outermost side generate parasitic capacitance not only through the bottom surface of the lower cover but also through the side wall of the lower cover, which is more parasitic than other lamps in other areas. As the capacity increases, the amount of current leaking from the outermost lamps increases.

Hereinafter, with reference to the accompanying drawings to check the associated experimental data.

2 (a) and 2 (b) are graphs and diagrams comparing the amount of tube current applied to the lamp without the lower cover with the amount of tube current increased after the lamp is placed on the lower cover. 3 (b) is a graph and a diagram showing the amount of leakage current measured through FIGS. 2 (a) and 2 (b).

2 (a), 2 (b), 3 (a) and 3 (b) above are obtained after experimenting with 25 lamps arranged on the basis of a 42-inch liquid crystal display. .

2 (a) and 2 (b), and FIGS. 3 (a) and 3 (b), each of the 25 lamps with lamps open at the bottom cover of 100 mA each at 100 mA It can be seen that the tube current is applied.

However, when the lamp is provided on the lower cover (LCM (Vout)), the amount of tube current applied from all the lamps is increased by about 27 mA on average, as shown in FIGS. 3 (a) and 3 (b). Likewise, it can be interpreted as the amount of leakage current generated in the lamp.

In addition, in the graph of FIG. 2 (a), it can be seen that the tube current amount increases from the center area toward the left and right sides, which means that the leakage current amount increases from the lamp disposed in the center area of the lower cover toward the side. To show.

As also confirmed through such experiments, the power consumption for driving the lamp is preferentially increased due to leakage current between the lower cover and the lamp.

In addition, the overall luminance of the liquid crystal display is lowered due to leakage current between the lower cover and the lamp, and local luminance decrease in the edge region is further generated.

In addition, a dark phenomenon, that is, a dark portion, may be more clearly seen in the corner region of the LCD.

As a result, such uneven brightness in the edge region including the edge region of the liquid crystal display device is one of the causes of deterioration of display quality such as the appearance of the screen.

The present invention has been made to solve the above problems, the object of which is to detect the leakage current (or leakage voltage) of the fluorescent lamp to use the leakage current generated between the lower cover and the fluorescent lamp as the driving voltage of the LED light emitting means. The present invention provides a liquid crystal display device having a conductive member to be connected and an LED light emitting means connected to and driven by the conductive member.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a lower cover having a bottom frame and sidewalls extending from at least one edge of the bottom frame; A plurality of first light emitting means arranged and arranged at regular intervals on the lower cover, the first light emitting means being disposed in parallel with the sidewalls; PCBs provided at both sides of the lower cover to fasten the first light emitting means and to receive a voltage from the outside; A conductive member disposed on the lower cover in parallel with the PCB and detecting a leakage current of the first light emitting means by a first conductive electrode formed on a guide holder to which the first light emitting means is fastened; And a second conductive electrode and a third conductive electrode which are provided at at least one side of the first light emitting means disposed at the outermost part of the lower cover, and electrically connected to the conductive member and the lower cover, respectively, on both sides thereof. And a second light emitting means driven by the detected leakage current.

In addition, the liquid crystal display according to the second embodiment of the present invention includes a bottom cover having a bottom frame and sidewalls extending from at least one edge of the bottom frame; A plurality of first light emitting means arranged and arranged at regular intervals on the lower cover, the first light emitting means being disposed in parallel with the sidewalls; PCBs provided at both sides of the lower cover to fasten the first light emitting means and to receive a voltage from the outside; A conductive member disposed on the lower cover in parallel with the PCB and detecting a leakage current of the first light emitting means by a first conductive electrode formed on a guide holder to which the first light emitting means is fastened; And a second conductive electrode provided in at least one corner region of the lower cover and provided on at least one side of the first light emitting means disposed at the outermost portion of the lower cover, and electrically connected to the conductive member and the lower cover, respectively, on both sides; And a second light emitting means which is formed by a third conductive electrode and driven by a leakage current detected from the conductive member.

As a result of the above configuration, the liquid crystal display according to the present invention has a plurality of lamps arranged on the lower cover and the LED light emitting means is provided on at least one side of the outermost of the plurality of lamps, the luminance compared to the other areas relatively It is possible to compensate for the luminance in the edge region that was low.

In addition, by driving the LED light emitting means provided on at least one side of the outermost lamp by using the leakage current of the lamp, power consumption may be considerably reduced compared to when configuring a separate drive unit.

Hereinafter, the configuration will be described in more detail with reference to the accompanying drawings.

4 is an exploded perspective view of a liquid crystal display according to a first exemplary embodiment of the present invention, and FIG. 5A is a cross-sectional view taken along a cutting line II ′ of the conductive member and the LED light emitting means provided on the lower cover of FIG. 4. 5B is a cross-sectional view taken along the cutting line II-II` of the conductive member and the LED light emitting means provided on the lower cover.

4, 5A and 5B, the liquid crystal display according to the first embodiment of the present invention is located on the upper side of the main support 150 to maintain the balance of the force acting on the entire structure. The liquid crystal panel 160, which implements an image, is mounted, and a backlight device is provided below the liquid crystal panel 160 to provide light to the liquid crystal panel 160. Here, the backlight device includes a first light emitting means as a light source, for example, a plurality of fluorescent lamps 120 and a second light source provided on at least one side of the outermost lamp 120 among the plurality of fluorescent lamps 120 to provide light. It comprises a light emitting means, such as an LED (or OLED) light emitting means 125 and an optical member 147 to complement the optical characteristics of the light provided from the fluorescent lamp 120 and the LED light emitting means (125).

Here, since the leakage current or voltage obtained by the conductive member 130 from the fluorescent lamp 120 may be a floating sine wave voltage, the LED light emitting means 125 is an LED element on the LED light emitting means 125. Or a rectifying circuit portion for full-wave rectifying or half-wave rectifying the floated sinusoidal voltage to drive the LED package 126, a smoothing circuit portion for smoothing the rectified voltage, and a divided voltage for dividing the smoothed DC voltage through a resistor or the like. It may further include a separate drive unit consisting of a circuit portion.

First, as shown in the drawing, the lower cover 100 is made of iron (Fe) or electro galvanized iron (EGI), or the like, and has a flat bottom surface and a bottom frame having a bottom surface. It consists of side walls extending and formed at both edges. At this time, a rectangular concave groove is formed on the bottom frame in a direction perpendicular to the long axis direction of the side wall frame.

In addition, both sides of the lower cover 100 formed as described above are provided with a first balance PCB 103a and a second balance PCB 103b. In this case, a lamp socket (not shown) to which an alternating current high voltage is applied from the outside is included on the first balance PCB 103a and the second balance PCB 103b, and a plurality of lamps 120 are arranged and fixed through the lamp socket. have.

More specifically, the first balance PCB 103a and the second balance PCB 103b may include a connector (not shown) and a lamp socket (not shown) to allow a high voltage of an alternating current to flow from an external first inverter PCB and a second inverter PCB. A ballast capacitor is additionally formed to provide a uniform current to the lamp 120 before the AC voltage is introduced into the lamp 120.

At this time, each of the lamps 120 fastened to the lamp sockets on the first balance PCB 103a and the second balance PCB 103b may be driven in a high-high manner in which high voltage of alternating current is applied at both sides thereof. At this time, the high voltage of the alternating current is applied to the first balance PCB 103a from the first inverter PCB (not shown), which is set as the master, and from the external second inverter PCB which is set as the slave. The high voltage of the alternating current is applied to the second balance PCB 103b.

In addition, a conductive member 130 is provided in the rectangular concave groove formed on the bottom surface of the lower cover 100. At this time, the conductive member 130 is located at the 1 / 3L and 2 / 3L points when dividing the total length (L) of the lamp 120 by three, or the total length (M) of the lamp 120 When divided into four, it is preferable to be located at 1 / 4M and 3 / 4M points, respectively, which position may be related to the magnitude of the leakage current (or leakage voltage) detected by the conductive member 130. .

The conductive member 130 basically includes an outer frame 133 made of an insulating material and conductive means 134 and 135 formed inside the outer frame 133, where the outer frame 133 is A main frame 131 provided on the lower cover 100 and a guide holder 132 extending and formed perpendicular to the main frame 131 to which the lamp 120 is fastened. 134 and 135 are formed in the guide holder 132 and connect the first conductive electrode (or common electrode) 135 and the first conductive electrode 135 to contact the lamp 120, respectively. The conductive wiring 134 formed inside the main frame 131 and the inside of the 132 is shown.

Of course, the conductive member 130 further includes a hole for exposing the conductive wiring 134 formed inside the outer frame 133 to at least one side of the long axis direction, wherein one side of the outer frame 133 is present. The exposed electrode 136 formed by connecting to the conductive wiring 134 exposed through the hole formed on the upper side or the conductive wiring 134 is a second conductive electrode of the LED light emitting means 125, that is, a positive electrode (+) The pattern 128 is connected.

As a result, when the conductive members 130 are provided on both sides of the lower cover 100 as in the present invention, for example, the conductive wiring 134 is exposed on one side of the upper surface of one conductive member 130. The formed hole part is located in correspondence with the hole part formed by exposing the conductive wiring 134 on the upper side of the other side in the other conductive member 130 facing each other with one conductive member 130.

In addition, on the lower region 100 of the center region between the conductive member 130 and the conductive member 130 provided on the lower cover 100 and / or the first balance PCB 103a and the second balance PCB ( The first reflecting plate 101 is attached on the lower cover 100 between the 103b) and the conductive member 130. Of course, the material may be a white polyester film or a film coated with a metal (Ag, Al), etc., the light reflectance of the visible light in the first reflector 101 is about 90 ~ 97% and the coated film is thick The higher the reflectance becomes.

And, on the lower cover 100 between the conductive member 130 and the conductive member 130 provided on both sides of the lower cover 100, the second light emitting means in a direction perpendicular to the conductive member 130, For example, an LED (or OLED) light emitting means 125 is provided. At this time, the LED package 126 is formed on the LED light emitting means 125, the LED light emitting means to drive the plurality of LED packages 126 in parallel between the conductive member 130 and the lower cover 100 ( The positive (+) electrode pattern 128 formed at one lower end portion in the long axis direction of the 125 has a second conductive electrode contacting the conductive wiring 134 or the conductive wiring 134 exposed from the upper side of the conductive member 130 ( 136 is connected to each other, while the third conductive electrode, ie, the ground electrode pattern 129 formed at the lower end of the other side in the long axis direction of the LED light emitting unit 125 is connected to the lower cover 100.

Here, on the LED light emitting means 125 is formed between the conductive wiring 134 exposed from the upper portion of the conductive member 125 and the positive electrode pattern 128 of the LED light emitting means 125 as mentioned above In order to rectify and smooth the floating sinusoidal voltage from the lamp 120 applied through the conductive member 125, a separate driving part may be additionally applied to the LED light emitting unit 125 by dividing the voltage.

In addition, a second reflector (not shown) for exposing the LED package 126 to the outside may be additionally attached on the LED light emitting means 125. At this time, the material may be a film coated with a white polyester film or a metal (Ag, Al) and the like as the first reflector 101, the light reflectance of the visible light in the second reflector is 90 ~ 97 The thicker the coated film, the higher the reflectance.

The lamp 120 is prevented from being bent on the center area lower cover 100 between the first balance PCB 103a and the second balance PCB 103b to which the first reflecting plate 101 is attached, and prevents the lamp ( A lamp guide (not shown) for protecting the 120 may be additionally provided. At this time, the lamp guide is composed of a holder portion to which the lamp 120 is fastened and a conical horn-shaped support portion to prevent sagging of the optical member provided on the upper side of the lamp 120.

In addition, the lamp socket (not shown) on the first balance PCB 103a and the second balance PCB 103b provided on both sides of the lower cover 100, and the conductive member 130 arranged in parallel with the lamp socket. A plurality of lamps 120 are fastened to the guide holder 132 and / or the lamp holder part of the lamp guide and arranged at regular intervals.

In this case, as the lamp 120, an external electrofluorescent lamp (EEFL) is appropriately fastened to the first balance PCB 103a and the second balance PCB 103b, but this is only one example. Various types of lamps such as Cold Cathode Fluorescent Lamps may be provided and used on the lower cover 100.

In addition, both sides of the lower cover 100 include a first balance PCB 103a and a second balance PCB 103b therein, and the first balance PCB 103a and the second balance PCB 103b outside. A predetermined fixing member, that is, the side support 140, is protected to protect from the load.

In addition, both sides are supported by the side support 140 so that the light emitted directly from the lamp 120 and the light reflected through the first reflector 101 and the second reflector above the lamp 120. The optical member 147 which distributes them uniformly to the whole surface of the liquid crystal panel 160 is mounted. In this case, the optical member 147 may be a diffuser plate, and an optical sheet such as a prism sheet and a protective sheet, which is added to the diffuser plate and has additional characteristics such as increasing the front luminance of light passing through the diffuser plate. Can be.

The main support 150 is fastened on the upper side of the optical member 147 to maintain the balance of the overall force in the liquid crystal display. At this time, the main support 150 is made of synthetic resin or stainless steel to form a rectangular frame, the upper side is divided into the inner side and the outer side to form a step (段差) formed with a low height along the inner side. It is coming true.

In addition, the liquid crystal panel 150 is mounted on the main support 140. The liquid crystal panel 150 includes an array substrate in which thin film transistors are arranged for each unit pixel, a color filter substrate having a color filter corresponding thereto, and a liquid crystal injected between the two substrates.

The upper cover 160 is fastened to the lower cover 100 while surrounding the four side edge regions of the liquid crystal panel 160 and the side surfaces of the main support 150.

FIG. 6 is an equivalent circuit diagram illustrating a driving state of a conductive member provided on the lower cover of FIG. 4 and an LED light emitting means connected to the conductive member.

Referring to FIG. 6, with reference to FIG. 4, for example, an AC voltage of about 1500 KV may be input from an external first inverter PCB to the first balance PCB 103a on one side of the lower cover 100. Of course, the second balance PCB 103b provided on the lower cover 100 and disposed on the other side is similarly applied.

When the input voltage Vin is simultaneously applied to the plurality of lamps 120 provided on the lower cover 100, the conductive member 230 is disposed between the lower cover 100 and the plurality of lamps 120. The floating leakage current (or leakage voltage) of about 50V is detected from the parasitic capacitors C1 to Cn.

In addition, the AC voltage of the floating state detected by the conductive member 230 is applied to the first to mth LED packages (LED1 to LEDm) 126 configured in the LED light emitting means unit 225, in which the floating state. AC voltage of the voltage conversion unit including a rectifying circuit section for half-wave or full-wave rectification of the AC voltage, and a smoothing circuit section for smoothing the rectified voltage to a DC voltage, and divides the smooth DC voltage through a resistor or the like. It may be applied to the LED package 126 via the voltage divider circuit. For example, if the LED package 126 is operated at 34V, in order to drive the LED package 126 may be applied after proper voltage distribution is made through the voltage divider circuit portion.

7 is an exploded perspective view of a liquid crystal display according to a second exemplary embodiment of the present invention, and FIG. 8A is a view along the cut line III-III` of the conductive member and the LED light emitting means provided on the lower cover of FIG. 8B is a cross-sectional view taken along a cutting line IV-IV` of the conductive member and the LED light emitting means provided on the lower cover.

7 and 8A and 8B, the liquid crystal display according to the second embodiment of the present invention is an LED (or OLED) as the second light emitting means to the corner region of the lower cover 300 as compared with the first embodiment. The light emitting means 325 is slightly different from each other.

Accordingly, in the liquid crystal display according to the second embodiment of the present invention, a liquid crystal panel 360, in which an image is implemented, is mounted on the upper side of the main support 349, and light is placed on the liquid crystal panel 360 on the lower side thereof. There is provided a backlight device. Here, the backlight device is provided in at least one corner region of the first light emitting means as a light source, for example, a plurality of fluorescent lamps 320 and the outermost lamp 320 of the plurality of fluorescent lamps 320 to provide light. LED light emitting means 325 and the fluorescent lamp 320 and the optical member 347 to complement the optical characteristics of the light provided from the LED light emitting means 325 is configured.

In this case, the LED light emitting means 325 includes at least one of a substrate and an LED device, an LED package 326 or an OLED that is fixed and arranged in at least one row on the substrate, such LED light emitting means 325 ) Is driven through an electrical connection with a separate conductive member 330 for detecting or acquiring current leaking from the fluorescent lamp 320.

Here, since the leakage current or the leakage voltage detected by the conductive member 330 from the fluorescent lamp 320 may be a floating sine wave voltage, the LED light emitting means 325 is an LED element or LED on the LED light emitting means 325. A rectifying circuit portion for full-wave rectifying or half-wave rectifying the floated sinusoidal voltage to drive the package 326, a smoothing circuit portion for smoothing the rectified voltage, and a voltage divider circuit portion for dividing the smoothed DC voltage through a resistor or the like. It may further include a separate drive unit made of.

First, as shown in the figure, the lower cover 300 is a bottom frame having a flat bottom surface made of iron (Fe) or galvanized steel sheet (EGI), etc., and sidewalls extending and formed at both edges of the bottom frame. It consists of. At this time, a rectangular concave groove is formed on the bottom frame in a direction perpendicular to the long axis direction of the side wall frame.

The first balance PCB 303a and the second balance PCB 303b are provided at both sides of the lower cover 300 formed as described above. At this time, a lamp socket (not shown) to which an alternating current high voltage is applied from the outside is included on the first balance PCB 303a and the second balance PCB 303b, and a plurality of lamps 320 are arranged and fixed through the lamp socket. have.

More specifically, the first balance PCB 303a and the second balance PCB 303b may include a connector (not shown) and a lamp socket (not shown) to allow a high voltage of an alternating current to flow from an external first inverter PCB and a second inverter PCB. The ballast capacitor (ballast capacitor) for providing a uniform current to the lamp 320 in the step before the AC voltage is introduced into the) is additionally formed.

In this case, each of the lamps 320 fastened to the lamp sockets on the first and second balance PCB 303a and 303b may be driven in a high-high manner in which a high voltage of AC is applied to both sides. At this time, the high voltage of the alternating current is applied to the first balance PCB 303a from the first inverter PCB set as the master, while the high voltage of the alternating current is applied to the second balance PCB 303b from the external second inverter PCB set as the slave. Is being applied.

In addition, a conductive member 330 is provided in a rectangular concave groove formed on the bottom surface of the lower cover 300. At this time, when the conductive member 330 divides the total length L of the lamp 320 into three parts, the conductive member 330 is located at 1 / 3L and 2 / 3L points of the lamp 320 or the total length M of the lamp 120. When divided into four, it is preferable to be located at 1 / 4M and 3 / 4M points, respectively, which position may be related to the magnitude of the leakage current (or leakage voltage) detected by the conductive member 330. .

The conductive member 330 basically includes an outer frame 333 made of an insulating material and conductive means 334 and 335 formed inside the outer frame 333, where the outer frame 333 is Means the main frame 331 provided on the lower cover 300 and the guide holder 332 is extended and formed perpendicular to the main frame 331 is guided and fastened to the lamp 320, the conductive means 334 , 335 is formed in the guide holder 332 to connect the first conductive electrode (or common electrode) 335 and the first conductive electrode 335 which are in contact with the lamp 320, respectively, to guide guide 332. The conductive wirings 334 formed in the interior and the interior of the main frame 331 are shown.

Of course, the conductive member 330 additionally includes a hole for exposing the conductive wiring 334 formed inside the outer frame 333 to at least one side of the long axis direction, wherein one side of the outer frame 333 The exposed electrode 336 formed by connecting to the conductive wiring 334 exposed through the hole formed on the upper side or the conductive wiring 334 is a second conductive electrode of the LED light emitting means 325, that is, a positive electrode (+) The pattern 328 is connected.

As a result, in the present invention and when the conductive member 330 is provided on both sides of the lower cover 300, for example, a hole formed by exposing the conductive wiring 334 to one upper surface of one conductive member 330 is exposed. The part is positioned to correspond to each other with the hole part formed by exposing the conductive wiring 334 on one side and the upper side of the other side in the other conductive member 330 disposed to face each other with the one conductive member 330.

In addition, on the lower region 300 and / or the first balance PCB 103a and the second balance PCB between the conductive member 330 and the conductive member 330 provided on the lower cover 300. The first reflecting plate 301 is attached on the lower cover 300 between the 103b) and the conductive member 330. Of course, the material may be a white polyester film or a film coated with a metal (Ag, Al), etc., the light reflectance of the visible light in the first reflector 301 is about 90 ~ 97% and the coated film is thick The higher the reflectance becomes.

In addition, at least one side of the conductive member 300 corresponding to the edge region of the lower cover 300 has a direction perpendicular to the conductive member 330, respectively, to emit second light emitting means, for example, LED (or OLED) light emitting device. Means 325 are provided. At this time, the LED package 326 is formed on the LED light emitting stage 325, the LED light emitting means to drive the at least one LED package 326 between the conductive member 330 and the lower cover 300 The positive electrode pattern 328 formed at the lower end of one side (in the long axis direction) of 325 may contact the conductive wiring 334 or the conductive wiring 334 exposed from the upper side of the conductive member 330. The conductive electrode 336 is connected to each other, while the third conductive electrode (ie, the ground electrode pattern 329) formed at the lower end of the other side of the LED light emitting unit 325 (in the long axis direction) is connected to the lower cover 300. Will be done.

Here, on the LED light emitting means 325 is formed between the conductive wiring 334 exposed from the upper side of the conductive member 325 and the positive electrode pattern 328 of the LED light emitting means 325 as described above A separate driving unit may be additionally included to rectify and smooth the floating sinusoidal voltage from the lamp 320 applied through the conductive member 325 and to divide the divided sinusoidal voltage into the LED light emitting unit 325.

In addition, a second reflector (not shown) for exposing the LED package 326 to the outside may be additionally attached on the LED light emitting means 325. In this case, the material may be a film coated with a white polyester film or a metal (Ag, Al) and the like as the first reflector 301, the light reflectance of the visible light in the second reflector is 90 ~ 97 The thicker the coated film, the higher the reflectance.

The lamp 320 is prevented from being bent on the central area lower cover 300 between the first balance PCB 303a and the second balance PCB 303b to which the first reflecting plate 301 is attached. Lamp guide (not shown) for protecting the 320 may be additionally provided. At this time, the lamp guide is composed of a holder portion to which the lamp 320 is fastened and a conical horn-shaped support to prevent sagging of the optical member provided on the upper side of the lamp 320.

In addition, a lamp socket (not shown) on the first balance PCB 303a and the second balance PCB 303b provided on both sides of the lower cover 300, and the conductive member 330 disposed in parallel with each other on the lamp socket. A plurality of lamps 320 are fastened to each other and arranged at regular intervals in the guide holder 332 or the holder of the lamp guide.

At this time, the lamp 320 is appropriate to use the EEFL with the first balance PCB 303a and the second balance PCB 303b. However, this is only one example. As a light source, various kinds of lamps such as CCFL may be provided and used on the lower cover 300.

Then, both sides of the lower cover 300 includes a first balance PCB 303a and a second balance PCB 303b therein, and the first balance PCB 303a and the second balance PCB 303b outside. The side support 340 which protects from this is mounted.

In addition, both sides of the side support 340 is supported, the light directly emitted from the lamp 320 above the lamp 320 and the light reflected through the first reflecting plate 301 and the second reflecting plate An optical member 347 is mounted to uniformly disperse the same to the entire surface of the liquid crystal panel 360. In this case, the optical member 347 may be a diffusion plate, and an optical sheet such as a prism sheet and a protective sheet, which is added to the diffusion plate and has additional characteristics such as increasing the front luminance of light passing through the diffusion plate. Can be.

The main support 350 is fastened on the upper side of the optical member 347 to maintain the balance of the overall force in the liquid crystal display. At this time, the main support 350 is formed of a rectangular frame made of synthetic resin or stainless steel, the upper side is divided into the inner and the outer side to form a step (段差) formed with a low height along the inner side It is coming true.

In addition, the liquid crystal panel 350 is mounted on the main support 340. The liquid crystal panel 350 includes an array substrate in which thin film transistors are arranged per unit pixel, a color filter substrate having a color filter corresponding thereto, and a liquid crystal injected between the two substrates.

The upper cover 360 is fastened to the lower cover 300 while surrounding the four side edge regions of the liquid crystal panel 360 and the side surfaces of the main support 350.

1 is an exploded perspective view of a general direct type liquid crystal display device

2 (a) and 2 (b) are graphs and diagrams comparing the amount of tube current applied to the lamp without the lower cover with the amount of tube current increased after placing the lamp on the lower cover.

3 (a) and 3 (b) are graphs and charts showing the leakage current measured through FIGS. 2 (a) and 2 (b).

4 is an exploded perspective view of a liquid crystal display according to a first embodiment of the present invention.

5A is a cross-sectional view taken along a cutting line I-I` of the conductive member and the LED light emitting means provided on the lower cover of FIG.

5B is a cross-sectional view taken along a cutting line II-II ′ of the conductive member and the LED light emitting means provided on the lower cover.

FIG. 6 is an equivalent circuit diagram illustrating a driving state of a conductive member provided on the lower cover of FIG. 4 and an LED light emitting unit connected to the conductive member.

7 is an exploded perspective view of a liquid crystal display according to a second embodiment of the present invention.

FIG. 8A is a cross-sectional view taken along a cutting line III-III` of the conductive member and the LED light emitting means provided on the lower cover of FIG.

8B is a cross-sectional view taken along a cutting line IV-IV` of the conductive member and the LED light emitting means provided on the lower cover;

Claims

A lower cover having a bottom frame and sidewalls extending from at least one edge of the bottom frame;

A plurality of first light emitting means arranged and arranged at regular intervals on the lower cover, the first light emitting means being disposed in parallel with the sidewalls;

PCBs (Printed Circuit Board) are provided on both sides of the lower cover is fastened the first light emitting means, the voltage is applied from the outside;

A conductive member disposed on the lower cover in parallel with the PCB and detecting a leakage current of the first light emitting means by a first conductive electrode formed on a guide holder to which the first light emitting means is fastened;

A second conductive electrode and a third conductive electrode which are provided on at least one side of the first light emitting means disposed at the outermost side of the lower cover and electrically connect to the conductive member and the lower cover, respectively, are formed on both sides to detect from the conductive member. And a second light emitting means driven by the leakage current.

The liquid crystal display of claim 1, wherein the first light emitting means comprises any one of an external electrofluorescent lamp (EEFL) and a cold cathode fluorescent lamp (CCFL).

The liquid crystal display of claim 1, wherein the second light emitting means comprises one of a light emitting diode (LED) or an organic light emitting diode (OLED).

The conductive member of claim 1, wherein the conductive member is formed of an insulating material, the main frame contacting the lower cover, a guide holder extended and formed perpendicular to the main frame to fasten a lamp, and formed on the guide holder. A first conductive electrode contacting the lamp; And conductive wirings formed in the main frame and the guide holder by connecting the first conductive electrodes, respectively.

2. The liquid crystal display device according to claim 1, wherein the conductive member is provided at the 1 / 3L point and the 2 / 3L point, respectively, when dividing the entire length L of the lamp into three equal parts.

2. The liquid crystal display device according to claim 1, wherein the conductive member is provided at the 1 / 4M point and the 3 / 4M point, respectively, when dividing the entire length M of the lamp into quarters.

The liquid crystal display device according to claim 1, wherein the second conductive electrode of the second light emitting means connected to the first conductive electrode of the conductive member is a positive electrode.

The liquid crystal display device according to claim 1, wherein the third conductive electrode of the second light emitting means connected to the lower cover is a ground electrode.

2. The liquid crystal display device according to claim 1, wherein a driving circuit portion may be further configured between the second conductive electrodes of the second light emitting means connected to the first conductive electrodes of the conductive member.

The liquid crystal display of claim 9, wherein the driving circuit unit comprises a rectifying circuit unit for propagating or half-wave rectifying an AC voltage, a smoothing circuit unit for smoothing the rectified voltage, and a voltage divider circuit unit for dividing the smoothed voltage.

A second conductive electrode provided on at least one edge region of the lower cover and provided on at least one side of the first light emitting means disposed at the outermost portion of the lower cover, and electrically connected to the conductive member and the lower cover respectively on both sides; And a second light emitting means formed by three conductive electrodes and driven by a leakage current detected from the conductive member.

12. The liquid crystal display of claim 11, wherein the first light emitting means is one of an external electrofluorescent lamp (EEFL) and a cold cathode fluorescent lamp (CCFL).

12. The liquid crystal display device according to claim 11, wherein the second light emitting means comprises one of a light emitting diode (LED) or an organic light emitting diode (OLED).

The method of claim 11, wherein the conductive member is made of an insulating material (main frame) in contact with the lower cover, a guide holder extending and formed perpendicular to the main frame to fasten the lamp, and formed in the guide A first conductive electrode in contact with the lamp; And conductive wirings formed in the main frame and the guide holder by connecting the first conductive electrodes, respectively.

12. The liquid crystal display device according to claim 11, wherein the conductive member is provided at the 1 / 3L point and the 2 / 3L point, respectively, when the total length L of the lamp is divided into three equal parts.

12. The liquid crystal display device according to claim 11, wherein the conductive member is provided at the 1 / 4M point and the 3 / 4M point respectively when dividing the entire length M of the lamp into four equal parts.

12. The liquid crystal display device according to claim 11, wherein the second conductive electrode of the second light emitting means connected to the first conductive electrode of the conductive member is a positive electrode.

12. The liquid crystal display device according to claim 11, wherein the third conductive electrode of the second light emitting means connected to the lower cover is a ground electrode.

12. The liquid crystal display device according to claim 11, wherein a driving circuit portion may be further configured between the second conductive electrodes of the second light emitting means connected to the first conductive electrodes of the conductive member.

20. The liquid crystal display of claim 19, wherein the driving circuit unit comprises a rectifying circuit unit for propagating or half-wave rectifying an AC voltage, a smoothing circuit unit for smoothing the rectified voltage, and a voltage divider circuit unit for dividing the smoothed voltage.