KR20080073164A - Liquid crystal display device and back-light structure thereof - Google Patents

Abstract

An LCD(Liquid Crystal Display) and a backlight unit used for the same are provided to reduce a bezel area compared with the conventional LCD of the same scale by disposing balance PCBs(Printed Circuit Boards) vertically on both sidewalls of a lower cover, thereby widening the range of image reproduction. Balance PCBs(101,103) are vertically disposed on both sidewalls of a lower cover(100) and receive alternating high voltage to drive a plurality of lamps(120). The balance PCBs are composed of connectors(101a,103a) for receiving the alternating high voltage from first and second inverters, ballast capacitors(101b,103b) for receiving the alternating high voltage to supply stable current, and lamp sockets(101c,103c) for stably inputting the ballast current to the lamps. The lamp sockets have predetermined angles so that the lamps are easily arranged and joined to the lamp socket. A reflection plate(105) is attached to the lower cover between the balance PCBs.

Description

Liquid crystal display and backlight structure {LIQUID CRYSTAL DISPLAY DEVICE AND BACK-LIGHT STRUCTURE THEREOF}

1 is a cross-sectional view of a liquid crystal display device according to the related art.

2 is a perspective view illustrating the backlight structure of FIG. 1;

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

4 is a perspective view showing the balance PCB of FIG.

5 is a perspective view showing the lamp socket of FIG.

※※ Explanation of symbols for main parts of drawing ※※

100: lower cover 101, 103: balance PCB

101a, 103a: connector 103b: ballast capacitor

101c and 103c: lampholder 201: conductive electrode terminal

202: housing 203: holder

The present invention relates to a liquid crystal display device and a backlight structure, and more particularly, in the case of a direct type liquid crystal display device, a lamp socket is formed on a balance PCB vertically provided on both sides of a lower cover, so that a more efficient lamp can be fastened. It's about reducing the bazzel, which is the border of the screen.

In general, liquid crystal display devices tend to be gradually widened due to light weight, thinness, and low power consumption, and according to such trends, liquid crystal displays (LCDs) are used for office automation equipment and audio / video equipment. It is used in various fields. Of course, the LCD may display a desired image on the screen by adjusting the transmission amount of the light beam according to the image signal applied to the control switches arranged in a matrix form.

However, LCDs also have a problem in that light is provided from a backlight device for reasons other than self-luminous display devices that emit light. As a result, a cold cathode tube (CCFL) is used as a light source that provides light, where CCFL is a light tube using a cold cathode emission phenomenon, which is an electron emission generated by a strong electric field applied to the cathode surface. It is known to be easy to low heat generation, high brightness, long life, full color. Therefore, the liquid crystal display using the CCFL uses a direct type backlight device using a plurality of CCFLs according to the trend of larger size.

Of course, when the direct backlight device drives a plurality of CCFLs in parallel using a transformer, some of the plurality of CCFLs may be driven by the discharge characteristics of the CCFLs. In other words, the CCFL has an infinite resistance value before being discharged, whereas the CCFL has a small resistance value due to the plasma of the conductor generated inside the glass tube after discharge. Accordingly, when the CCFL is discharged, the resistance value decreases from the initial stage, thereby increasing the amount of current. Therefore, when a plurality of CCFLs are connected in parallel, the current flows toward the CCFL having a small resistance value after the initial discharge, so that some of the plurality of CCFLs are driven and the others are not driven.

As part of solving this problem, the same equivalent capacitor, or ballast capacitor, is attached to each CCFL anode to form the same equivalent circuit as the External Electrode Fluorescent Lamp (EEFL). A lamp driving device of a liquid crystal display device capable of driving a plurality of CCFLs in parallel using a single transformer has been proposed. Here, the EEFL is to be turned on by applying an AC power to the external electrode, that is, the discharge occurs in the discharge space inside the glass tube by the electric field by the high frequency voltage applied to the pair of external electrodes, The fluorescent material coated on the inner circumferential surface of the glass tube by ultraviolet rays emits visible light.

Then, we will briefly examine the balance PCB in which the ballast capacitor is formed. 1 is a cross-sectional view showing the configuration of a direct type liquid crystal display device having a balance PCB according to the prior art. Although not separately shown in the drawings, first, a reflector (not shown) is attached on the lower cover 41 to reflect the light to the front from the plurality of lamps 48 which are light sources.

In addition, balance PCBs 49a and 49b having a plurality of CCFLs coupled to both sidewalls of the lower cover 41 are provided. Of course, the balance PCBs 49a and 49b are connected to inverter PCBs 50a and 50b for applying an alternating voltage again, which will be described later.

In addition, a diffuser plate 43 and other optical complementary functions 44 are loaded to uniformly disperse the light reflected from the lamps 48 through the reflector (not shown) to the front.

After the backlight device is completed as described above, a main support (not shown) is fastened to maintain the balance of the overall force of the liquid crystal display device, although not separately shown in the drawings. Of course, the main support (not shown) forms a predetermined pattern in consideration of the liquid crystal panel 20 loaded upward.

The liquid crystal panel 20 mounted on the main support (not shown) is formed by many unit processes. In other words, this is an array substrate 20a in which a thin film transistor as a switching element is arranged for each unit pixel, a color filter substrate 20b having a color filter corresponding thereto, and a liquid crystal injected between two substrates. It is configured to include.

Although not shown separately in the drawing, the upper cover (not shown) is fastened to the lower cover 41 through a separate fastening method while surrounding the outer edge of the liquid crystal panel 20 and the side of the main support (not shown).

Now, the backlight driving apparatus according to the related art will be described in more detail with reference to FIG. 2. FIG. 2 is a perspective view illustrating the backlight structure of FIG. 1 and illustrates a view of the balance PCBs 49a and 49b on the lower cover 41 and the inverter PCBs 50a and 50b linked thereto.

As shown in the figure, the inverter PCB 50a, 50b converts the DC power supplied from the outside into an AC voltage, and then converts the AC voltage into an AC voltage having a high voltage, and the AC high voltage again controls the integrated circuit. Is applied to the balance PCBs 49a and 49b through the output connectors of the inverter PCBs 50a and 50b.

The alternating current high voltage applied to the balance PCBs 49a and 49b is supplied to each ballast capacitor through a conductive wire and a high voltage supply pattern to equalize the amount of current flowing into the tubes of the plurality of CCFLs 48, respectively. Flows back into the lamp 48, which is connected in correspondence with the ballast capacitor, respectively.

However, in such a conventional configuration, the wires and the plurality of lamps 48 that are fastened by soldering on the balance PCBs 49a and 49b cause a lot of trouble in the fastening process and the assembly process of the liquid crystal display device. This, in turn, leads to a lot of time wasted in the assembly process.

In addition, in the related art, in order for the light emitted from the lamp 48 to be reflected from the reflecting plate and efficiently reach the liquid crystal panel, a distance between the plurality of lamps and the reflecting plate must be considered, but there is no mention of this. When the lamps are fastened on the balance PCBs 49a and 49b provided at both sides of the 41, the reflection efficiency of the light is considerably lowered, which causes problems in image realization of the liquid crystal panel.

In addition, in order to obtain a uniform brightness from the backlight as the liquid crystal display device becomes more and more recent, a stable current must be provided to the lamp, and the area occupied by the balance PCBs 49a and 49b on the lower cover is further increased. As a result, the bezel, which is a border portion of the screen, increases, and as a result, an image realization range is reduced compared to the same scale of a conventional LCD.

Accordingly, an object of the present invention is to provide a liquid crystal display device by vertically providing a balance PCB on both sidewalls of the lower cover and fixing a lamp socket on the balance PCB in order to improve the above problems.

And the achievement of this object can be further embodied by the present invention. That is, the liquid crystal display according to the present invention includes a lower cover; A lamp provided on the lower cover to provide light; A balance PCB (Printed Circuit Board) provided on both sides of the lower cover; Lamp fixing means fixed on the balance PCB, the lead of the lamp being inserted in an upward direction to fix the lamp, and including conductive electrode terminals to which a voltage is applied from the outside through the balance PCB; And a liquid crystal panel receiving light from the lamp.

In addition, the backlight structure of the liquid crystal display according to the present invention includes a lower cover; A lamp provided on the lower cover to provide light; A balance PCB (Printed Circuit Board) provided on both sides of the lower cover; And a lamp fixing means fixed to the balance PCB, the lead of the lamp being inserted in an upward direction to fix the lamp, and having a conductive electrode terminal to which a voltage is applied from the outside through the balance PCB. It is characterized in that the configuration.

Then, with reference to the drawings with respect to the above configuration will be described in detail. 3 is an exploded perspective view of a liquid crystal display according to the present invention. As shown in the drawing, both sidewalls (or separate fixing means) of the lower cover 100 made of aluminum (Al) or the like are applied with an alternating current high voltage from an external first inverter and a second inverter and the lamp 120. Balance PCBs (101, 103) for driving the vertically provided.

In addition, the balance PCB (101, 103) is a ballast formed in a pattern to provide a stable current by applying the alternating high voltage from the connector (101a, 103a) to which the alternating current high voltage is applied from the external first and second inverters. Capacitors 101b and 103b and their ballast currents have a conductivity so that they can stably flow into the lamp 120 and at the same time a plurality of lamps 120 can be easily arranged and fastened to form a predetermined lamp socket ( 101c and 103c are comprised.

The reflective plate 105 is attached to the lower cover 100 corresponding to the center area of the balance PCBs 101 and 103 provided perpendicularly to both sides. Of course, the material of the reflector plate 105 is a film coated with a white polyester film or metal (Ag, Al), etc., the light reflectance of the visible light in the reflector 113 is about 90 ~ 97% and the coated film The thicker this is, the higher the reflectance is.

However, in the present invention, since the area occupied by the balance PCBs 101 and 103 vertically provided on both sides of the lower cover 100 is not large, the reflective plate 105 is first attached to the lower cover 100. The provision of the balance PCBs 101 and 103 vertically on both sides thereof cannot be excluded.

Subsequently, a plurality of lamps 120 are fastened to the lamp sockets 101c and 103c arranged and fixed on both balance PCBs 101 and 103 and bent upwards. In this case, the distance between the lamp 120 fastened to the lamp sockets 101c and 103c and the reflector plate 105 positioned on the rear surface of the lamp 120 may be maintained within a range of about 5 mm. For example, when the distance between the lamp 120 and the reflector 105 exceeds 5 mm, it may affect the optical sheet (not shown) fastened to the upper side to cause wrinkles due to heat.

Therefore, in order to adjust the separation distance between the reflecting plate 105 and the lamp 120, it can be formed by adjusting the height of the balance PCB (101, 103) provided perpendicular to both sides of the lower cover 100. Rather, the above problems can be overcome by controlling the predetermined angle formed by the lamp sockets 101c and 103c itself.

For example, the shape of the lampholders 101c and 103c may be freely bent and formed within a range in which the lamp 120 does not feel uncomfortable. Typically, a "C" shape or a "V" shape may be mentioned. . At this time, of course, one end is fixed on the balance PCB, the other end will be a holder portion to which the lamp 120 is fastened, which will be described later.

In addition, a plurality of lamps 120 are arranged in series in the “L” shaped lamp sockets 101c and 103c according to the preferred embodiment of the present invention, which is fixed on the balance PCBs 101 and 103 on both sides as shown in the drawing. In general, large-area LCD TVs are known to be arranged at regular intervals using about 16 lamps on a 32-inch basis and about 20 lamps on a 40-inch panel for high brightness. Of course, the lamp 150 may be any one of a Cold Cathode Fluorescent Lamp (CCFL) and an External Electrode Fluorescent Lamp (EEFL).

Subsequently, in order to protect the balance PCBs 101 and 103 including the lamp sockets 101c and 103c positioned at both sides, a predetermined fixing member, that is, the side support 130 is loaded.

Here, the frame of the side support 130 manufactured by the press working is inclined at a predetermined angle and the semi-circular lamp fixing part 130a1 for arranging and fixing the lamp 120 at a portion contacting the lower cover 100. And an inclined frame 130a, a vertical frame 130b formed in a vertical direction at a predetermined interval apart from the inclined frame 130a, and an upper frame 130c extending horizontally from each other on the upper sides of the two frames. .

Of course, these three frames are preferably formed integrally with each other, but can be manufactured and combined separately, and the inclined frame 130a may also be formed vertically like the vertical frame 130b, and thus various modifications thereto. Will be there.

In the present invention, the vertical frame 130b of the side support 130 is fastened between both sidewalls of the lower cover 100 and the balance PCBs 101 and 103. Therefore, in order for the connector 101a to which an alternating current high voltage is applied from the external first and second inverters to protrude outward, it may be required to form a hole in a portion of the vertical frame 130b.

However, instead of fastening the vertical frame 130b of the side support 130 between both sidewalls of the lower cover 100 and the balance PCBs 101 and 103 as in the above case, the outer sidewalls of both sidewalls of the lower cover 100 are not fastened. It is also possible to fasten by positioning.

After the fastening of the side support 130, a diffuser plate (not shown) for uniformly dispersing the light emitted directly from the plurality of lamps 120 and the light reflected through the reflector plate 105 to the front, and Optical sheets (not shown) are loaded so that light transmitted through the diffusion plate (not shown) has additional optical properties.

After the backlight configuration is completed, the main support 140 is fastened to maintain the balance of the overall force in the liquid crystal display. Of course, the main support 140 here forms a pattern in consideration of the liquid crystal panel 150 loaded on the front surface.

The liquid crystal panel 150 mounted on the main support 140 is composed of many unit processes. In other words, the switching element includes an array substrate in which thin film transistors are arranged in each unit pixel, a color filter substrate in which a color filter representing color is formed, and a liquid crystal injected between the two substrates. .

The upper cover 160 is fastened to the lower cover 100 while surrounding the four surface edges of the liquid crystal panel 150 and the side surfaces of the main support 140.

Hereinafter, the balance PCBs 101 and 103 of FIG. 3 will be described with reference to FIGS. 4 and 5. 4 is a perspective view illustrating the balance PCBs 101 and 103 of FIG. 3, and FIG. 5 is a perspective view illustrating the lamp sockets 101c and 103c of FIG. 4.

As shown in Fig. 4, the balance PCBs 101 and 103 are applied with an alternating current high voltage from external first and second inverters through the connectors 101a and 103a fixed through the upper connection holes. The alternating current high voltage is applied to a plurality of ballast capacitors 101b and 103b which are connected to the connectors 101a and 103a and connected to the high voltage supply patterns formed of the metal patterns, respectively, and output a stable current. In this case, the ballast current output through the ballast capacitors 101b and 103b is introduced into the lamp 120 via the electrode terminals of the lamp sockets 101c and 103c. As a result, the plurality of lamps 120 provide light of uniform brightness.

Referring to FIG. 5, the lamp sockets 101c and 103c according to the present invention have a housing 202 for forming an outer frame made of plastic, and a process pattern located under the housing 202. The “L” shaped conductive electrode terminal 201 electrically connected to one side polarity of the ballast capacitors 101b and 103b formed in the shape of the ballast capacitor 101, and the electrode portion or the electrode portion of the lamp 120 located above the housing 202. It consists of a holder 203 which inserts and holds a conductive lead connected to it.

As shown in the drawing, the lamp sockets 101c and 103c have the “L” shaped electrode terminal 201 and the holder 203 fastened to each other inside the housing 202. After inserting the lead connected to the electrode portion or the electrode portion of the lamp 120 to the receiving portion of the holder 203, and pressing the holder 203, the lead of the lamp 120 and the lamp socket 101c, 103c Electrode terminals 201 are electrically connected to each other. On the other hand, if the holder 203 of the lampholders 101c and 103c is performed in the reverse order, the lamp 120 may be replaced sufficiently.

In addition, as inferred from the above, in the case of a lamp having an electrode formed outside such as EEFL, the electrode terminal 201 of the lamp sockets 101c and 103c and the lamp 120 of the holder 203 according to the present invention. If the storage area is made wider, the EEFL can be fastened as efficiently as possible. Therefore, the lamp storage range of the electrode terminal 201 and the holder 203 of the lamp sockets 101c and 103c will not be particularly limited.

On the other hand, the lamp sockets 101c and 103c according to the present invention have been mentioned above, but can be changed to various shapes. Of course, the reason for changing the shape is different because the balance PCB (101, 103) is provided vertically to the side wall of the lower cover 100, for easier fastening of the lamp 120, a predetermined angle by itself The predetermined angle may be changed according to the model of the liquid crystal display device. Therefore, the predetermined angle should be determined in consideration of the reflection efficiency of light between the lamp 120 and the reflector plate 105.

Therefore, in the present invention, for example, in addition to the "L" shaped lamp sockets 101c and 103c, the reflector plate 105 or the lower portion of the holder 203 of the lamp sockets 101c and 103c can be easily fastened. The lamp sockets 101c and 103c having substantially "C" shape are formed by rounding the lamp sockets 101c and 103c themselves by 90 degrees under the assumption that they are perpendicular to the bottom surface of the cover 100. can do. Strictly speaking, it is preferable that the electrode terminals 201 of the lampholders 101c and 103c be formed in a "C" shape.

In addition, the portions of the holder 203 of the lamp sockets 101c and 103c having the “L” shape are kept perpendicular to the bottom surface of the reflector plate 105 or the lower cover 100 so that the lamp 120 may be fastened. Under the assumption that the lampholders 101c and 103c form 90 ° of their own, the lampholders 101c and 103c are formed in a substantially V shape by forming an obtuse angle of 90 degrees or more or an acute angle under the same conditions. You can do it. In addition, it is preferable that the electrode terminals 201 of the lampholders 101c and 103c are formed in a “V” shape as in the above.

Therefore, various modifications to the shape will be possible in addition to those based on the above contents, and in this regard, the scope of the claims will be described in the following claims.

As a result of the configuration up to now, the liquid crystal display and the backlight structure according to the present invention are provided with the balance PCB vertically on both side walls of the lower cover can reduce the bezel compared to the same scale of the conventional liquid crystal display device can be used a wide range of image implementation have.

In addition, by fixing the lampholders on the vertically balanced balance PCB, it is easy to fasten a plurality of lamps, and as a result, many time waste factors that can be caused in the assembling process of the liquid crystal display can be reduced, thereby improving the yield of the liquid crystal display. This is expected.

Claims (14)

Lower cover; A lamp provided on the lower cover to provide light; Balanced PCB (Printed Circuit Board) provided on both sides of the lower cover vertically; Lamp fixing means fixed on the balance PCB, the lead of the lamp being inserted in an upward direction to fix the lamp, and including conductive electrode terminals to which a voltage is applied from the outside through the balance PCB; And And a liquid crystal panel receiving light from the lamp. The apparatus of claim 1, wherein the balance PCB comprises: a connector configured to receive a voltage for driving a lamp; A plurality of ballast capacitors electrically connected to the connector to regulate respective amounts of current; And lamp fixing means for electrically connecting the ballast capacitors to each of the ballast capacitors. 3. The lamp of claim 2, wherein the lamp fixing means comprises: a conductive electrode terminal electrically connected to each ballast capacitor and bent upward; A holder accommodating the lamp in an upward direction and fastened to the electrode terminal; And a housing which protects the holder coupled to the electrode terminal from the outside. The liquid crystal display device according to claim 1, wherein the lamp fixing means extends to the balance PCB to form an "L" shape. The liquid crystal display device according to claim 1, wherein the lamp fixing means extends to the balance PCB to form a "V" shape. The liquid crystal display device according to claim 1, wherein the lamp fixing means extends to the balance PCB to form a "C" shape. The liquid crystal display device according to claim 1, wherein the lamp fixing means is a lamp socket. Lower cover; A lamp provided on the lower cover to provide light; Balanced PCB (Printed Circuit Board) provided on both sides of the lower cover vertically; And It is fixed on the balance PCB, the lamp lead is inserted in the upper direction to secure the lamp, comprising a lamp fixing means provided with a conductive electrode terminal is applied from the outside through the balance PCB Backlight structure of the liquid crystal display device. The apparatus of claim 8, wherein the balance PCB comprises: a connector configured to receive a voltage for driving a lamp; A plurality of ballast capacitors electrically connected to the connector to regulate respective amounts of current; And a lamp fixing means electrically connected to each of the ballast capacitors to fasten the lamps. 10. The apparatus of claim 9, wherein the lamp fixing means comprises: a conductive electrode terminal electrically connected to each ballast capacitor and bent upward; A holder accommodating the lamp in an upward direction and fastened to the electrode terminal; And a housing for protecting the holder coupled to the electrode terminal from the outside. 9. The backlight structure of claim 8, wherein the lamp fixing means extends to the balance PCB to form an "L" shape. The backlight structure of a liquid crystal display device according to claim 8, wherein the lamp fixing means extends to the balance PCB to form a "V" shape. The backlight structure of a liquid crystal display device according to claim 8, wherein the lamp fixing means extends to the balance PCB to form a "C" shape. The backlight structure of a liquid crystal display device according to claim 8, wherein the lamp fixing means is a lamp socket.

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