KR101338985B1 - Back light device and liquid crystal display device thereby - Google Patents

Abstract

The present invention relates to a liquid crystal display device which satisfies safety standards between patterns such as voltage wiring on a balance printed circuit board mounted inside the lower cover and prevents an increase in the area of the balance PCB due to the addition of the pattern. When a plurality of slits are formed in two lines on each side, the lower and odd-numbered slits are formed in different lines; A balance PCB provided on both sides of the lower cover to fix the lamp, the balance PCB having slits corresponding to the adjacent voltage wiring having a polarity opposite to the lamp fixing means, and a slit corresponding to the slits on the lower cover therebetween; An insulated mechanism fastened by a slit of the balance PCB to secure creepage and clearance while reducing a distance between the lamp fixing means and an adjacent voltage wiring; And a liquid crystal panel receiving light from the lamp.

Balance PCB, Slit, Insulation Fixture, Lamp Fixture, Voltage Wiring

Description

BACK LIGHT DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE THEREBY}

1 is a cross-sectional view of a liquid crystal display device having a balance PCB according to the prior art.

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

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

4 is a cross-sectional view of an embodiment of the backlight device of FIG. 3 taken along a cut plane I-I '.

5 is a cross-sectional view according to another exemplary embodiment when the backlight device of FIG. 3 is viewed along a cut plane I-I '.

Explanation of symbols on the main parts of the drawings

110a, 110b: Balance PCB 110a1, 110b1: Connector

110a2, 110b2: positive wiring 110a3, 110b3: negative wiring

110a4, 110b4: Ballast Capacitors 110a5, 110b5: Positive Lamp Socket

110a6, 110b6: Negative lampholder 110a7, 110b7: Insulation fixture

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device and a liquid crystal display device. More particularly, the present invention satisfies the safety standards between patterns such as voltage wiring on a balanced printed circuit board (PCB) mounted inside the lower cover. It is concerned with preventing further increase in the area of the balance PCB.

Generally, the liquid crystal display device has a tendency of widening its application range due to features such as light weight, thinness, and low power consumption driving. According to this trend, LCDs are used for office automation equipment and audio / video equipment. On the other hand, the LCD is controlled to transmit the light beam in accordance with the image signal applied to the control switches arranged in a matrix form to display a desired image on the screen.

However, despite these advantages, LCDs also have a problem of receiving light from the backlight device for reasons other than self-luminous display devices. Of course, a cold cathode tube (CCFL) is used as a light source that provides the light. Here, the CCFL is a light source tube using a cold cathode emission phenomenon, which is an electron emission generated by a strong electric field applied to the cathode surface. Low fever, high brightness, long life, full color. Therefore, a liquid crystal display using such a CCFL uses a direct-type backlight device using a plurality of CCFLs in accordance with an increase in size.

Of course, in the case of the direct type backlight device here, when a plurality of CCFLs are driven in parallel using one transformer, some of the plurality of CCFLs may be driven by the discharge characteristics of the CCFLs. Specifically, 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 the 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.

In order to solve this problem, the same equivalent capacitor, or ballast capacitor, is attached to the positive electrodes of a plurality of CCFLs to form the same equivalent circuit as the External Electrode Fluorescent Lamp (EEFL). There has been proposed a lamp driving device of a liquid crystal display device capable of driving a plurality of CCFLs in parallel using one transformer. Here, the EEFL is to be turned on by the application of 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 ultraviolet light is emitted from the phosphor coated on the inner circumferential surface of the glass tube to generate visible light.

Next, we will briefly discuss 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. As can be seen in the drawing, first, a reflecting plate 42 for reflecting light from the plurality of lamps 48 as a light source to the front is attached on the lower cover 41, and above, the plurality of CCFLs are fastened again. Balance PCBs 49a and 49b are provided at both sides, and inverter PCBs 50a and 50b are connected to the PCBs 49a and 49b, respectively, which will be described later. The diffuser plate 43 and other optical complementary functions 44 are loaded to uniformly disperse the light reflected from the lamps 48 through the reflector plate 42 to the front surface.

The steps up to now generally refer to a backlight device, which is not otherwise shown in the drawings, but a main support for fastening the overall power balance of the liquid crystal display device is fastened. Of course, the main support forms a predetermined pattern in consideration of the liquid crystal panel 20 loaded upward.

The liquid crystal panel 20 mounted on the main support 30 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 surrounds the outer edge of the liquid crystal panel 20 and the side of the main support, and is fastened to the lower cover 41 through a separate fastening method.

FIG. 2 is a perspective view illustrating the backlight device 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. Here, the inverter PCBs 50a and 50b convert the DC power supplied from the outside into an AC voltage, and convert the AC voltage into an AC voltage having a high voltage again. In addition, a plurality of capacitor patterns 49a1 and 49b1 are formed on the balance PCBs 49a and 49b, so that the amount of current flowing into the tubes of the plurality of CCFLs 48 is the same, and the inverter PCBs 50a and 50b are the same. By limiting the AC voltage supplied from the ()) serves to limit the current supplied to the plurality of CCFLs (48).

However, in the case of the balance PCB (49a, 49b), a voltage of, for example, 1500Vrms or more may be applied to the electrode portion of the lamp, in consideration of this, a problem arises in that a balance component or the like should be disposed.

Therefore, based on safety standards such as US 60950, if the high voltage patterns and components are additionally formed on the balance PCBs 49a and 49b, or additional components such as the inductor are mounted for more stable lamp driving, the balance is then applied. The area of the PCBs 49a and 49b is inevitably increased, resulting in an increase in manufacturing cost.

In addition, the bezel portion, which is the outer edge of the screen, increases in the modularization process of the LCD, resulting in a reduction in the active area of the image on the screen.

Therefore, in order to solve the above problems, first, voltage wirings are formed on the balance PCB under the premise that AC voltages of different phase differences are applied to the odd-numbered and even-numbered lamps on the balance PCB.

As a result, a separate insulation device is inserted between the voltage wiring and the lamp electrode so that the distance between the voltage wiring on the balance PCB and the electrode portion of the lamp fixing means for fixing the lamp satisfies conditions such as safety standards such as US 60950. There is a purpose.

And the achievement of this object can be further embodied through the present invention. That is, the liquid crystal display according to the present invention includes a liquid crystal display comprising: a lower cover in which a plurality of slits are formed in two lines on both sides, and odd-numbered slits and even-numbered slits are formed of different lines; Lamp fixing means for fixing the lamp, the lamp fixing means is provided on both sides on the lower cover, the voltage is provided to the lamp fixing means alternately provided with two voltages having opposite polarities, respectively formed in the edge region with the lamp fixing means therebetween; A balance printed circuit board (PCB) formed between a wiring and the lamp fixing means and the voltage wiring and including a slit corresponding to a slit on the lower cover; Insulation mechanism is fastened to the slit of the balance PCB through the slit of the lower cover, to secure the creepage and clearance distance while reducing the distance between the lamp fixing means and the voltage wiring; And a liquid crystal panel receiving light from the lamp.

In addition, the liquid crystal display according to another embodiment of the present invention is a lower cover; Lamp fixing means for fixing the lamp, the lamp fixing means is provided on both sides on the lower cover, the voltage is provided to the lamp fixing means alternately provided with two voltages having opposite polarities, respectively formed in the edge region with the lamp fixing means therebetween; A balance PCB fastened to wiring, a slit formed between the lamp fixing means and the voltage wiring, and the slit, the balance PCB having an insulation mechanism formed to secure a creepage and a clearance while reducing a distance between the lamp fixing means and the voltage wiring; And a liquid crystal panel receiving light from the lamp.

Then, the above configuration will be described in more detail with reference to the accompanying drawings. 3 is an exploded perspective view of the liquid crystal display according to the present invention. As can be seen in the drawing, first, on both sides of the lower cover 100 made of aluminum (Al) or the like, a plurality of slits, such as rectangular holes, are formed to be aligned to one side thereof. It is preferably formed as forming two lines, where the odd and even slits are formed as different lines to form two lines.

And, the balance PCB (110a, 110b) is provided on both sides of the lower cover 100, the slit is formed. Of course, the slits are formed on the balance PCBs 110a and 110b in the same areas as those of the slits of the lower cover 100.

In addition, by fixing and arranging the connectors 110a1 and 110b1 and the lamps 120 to allow a voltage to flow from an external inverter PCB (not shown), AC voltages of different phase differences from the connectors 110a1 and 110b1 are odd. And lamp sockets 110a5, 110a6, 110b5 and 110b6 to be applied to even-numbered lamps 120.

In addition, ballast capacitors 110a4 and 110b4 (ballast capacitors) for providing a uniform current to the lamp 120 may be formed before the AC voltage flows into the lamp sockets 110a5, 110a6, 110b5 and 110b6. .

The lamp sockets 110a5 and 110b6 110a6 and 110b5 on the balance PCBs 110a and 110b configured as described above have alternating AC voltages having different phase differences of 180 ° from one side and the other side based on one lamp 120. At the same time, even when the plurality of lamps 120 are referenced, AC voltages having 180 degrees of different phase differences are applied to one side of the odd-numbered and even-numbered lamps 120.

For example, when a positive phase alternating voltage is applied at the left side of the odd-numbered lamp 120 and the peak value of the applied voltage starts with a positive polarity, the upper positive phase alternating voltage is applied at the same left side of the even-numbered lamp 120. An antiphase AC voltage is applied whose peak value with a 180 degree phase difference starts with a negative polarity.

For this reason, the positive voltage wirings 110a2 and 110b2 (hereinafter, referred to as 'positive wiring') to which the positive phase AC voltage is applied and the negative polarity to which the reverse phase AC voltage are applied on the balance PCBs 110a and 110b. The voltage wirings 110a3 and 110b3 (hereinafter, referred to as 'negative wiring') are formed as edge regions of the balance PCBs 110a and 110b with the lamp sockets 110a5, 110a6, 110b5 and 110b6 interposed therebetween.

In addition, the negative wirings 110a3 and 110b3 formed on the balance PCBs 110a and 110b and passing close to the positive lamp sockets 110a5 and 110b5 to which a positive phase AC voltage is applied and the positive lamp sockets 110a5 and 110b5. ) And the slits formed between the negative wirings 110a6 and 110b6 to which the reverse phase AC voltage is applied and the positive wirings 110a2 and 110b2 passing close to the negative lamp sockets 110a6 and 110b6. Poly-based insulators such as polyethylene to secure creepage distances and clearances between safety sockets of different polarity (110a5, 110a6, 110b5, 110b6) and voltage wirings (110a2, 110b2, 110a3, 110b3) And 110a7 and 110b7. Of course, this is only a preferable example to the last, and the insulation mechanisms 110a7 and 110b7 are not necessarily limited to poly resins.

Above all, the creepage distance and the clearance in the safety standard, for example, when the power wiring is formed in the shape of a PCB on the PCB, the linear distance of two points becomes the spatial distance, and the surface distance down to the bottom Since it is a creepage distance, in the case of fastening the insulation mechanisms 110a7 and 110b7 as in the present invention, the positive lamp socket 110a5 and 110b5 and the negative wiring 110a3 and 110b3 or the negative lamp socket ( The distance measured between the surfaces of the insulating devices 110a7 and 110b7 between 110a6 and 110b6 and the positive wirings 110a2 and 110b2 is a creepage distance, while the straight distance exceeding the insulating devices 110a7 and 110b7 is It is a space distance.

As described above, the reflecting plate 101 is attached to the lower cover 100 of the center region except for the balance PCBs 110a and 110b provided at both sides of the lower cover 100. Of course, the material is a white polyester film or a film coated with a metal (Ag, Al), etc., the light reflectance of the visible light in the reflector 101 is about 90 ~ 97%, the thicker the coated film the reflectance Becomes high.

In addition, the lamp sockets 110a5, 110a6, 110b5, and 110b6 on the balance PCBs 110a and 110b positioned at both sides are fastened so that a plurality of lamps 120 are arranged in series. In the case of, it is known that approximately 16 lamps are arranged on a 32-inch basis for high brightness, and about 20 lamps are used at a 40-inch interval.

Of course, a predetermined fixing member, that is, the side support 130 is loaded in order to protect the balance PCBs 110a and 110b including the lamp sockets 110a5, 110a6, 110b5 and 110b6 positioned at both sides.

Then, a diffuser plate (not shown) and light emitted through the diffuser plate (not shown) for uniformly dispersing the light emitted directly from the lamps 120 and the light reflected through the reflector plate 101 to the front surface are Optical sheets (not shown) are loaded to have additional properties.

As such, when the loading process to the optical sheet (not shown), that is, the fastening process of the backlight device is finished, the main support 140 is fastened to maintain the balance of the overall force in the liquid crystal display device. 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 a crystal composed of many unit processes. In other words, the switching element comprises an array substrate in which thin film transistors are arranged for each unit pixel, a color filter substrate on 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.

Now, the backlight device according to the present invention will be described in more detail with reference to FIG. 4. FIG. 4 is a cross-sectional view of the backlight device of the liquid crystal display device shown in FIG. 3 taken along a cutting plane I-I '. First, as can be seen in Figure 4 (a), the insulating device (110a7) according to the present invention, as already mentioned earlier in the lamp socket 110a6 and the lamp socket (110a6) to which the reverse phase AC voltage is applied. It is fastened between the positive wiring 110a2 passing in close proximity. When the insulating device 110a7 is fastened to the opposite direction of the lamp socket 110a6 to which the lamp 120 is fastened, the height thereof is the height of the lamp socket 110a6. You will not be restricted.

On the other hand, when the insulating device (110b7) is located at the bottom of the lamp 120 as shown in Figure 4 (b) it is required to be fastened in a range that does not abut each other with the lamp 120, usually a lamp Considering that the distance between the 120 and the reflector 101 is in the range of 5 mm, the height of the insulating device 110b7 should be made lower than that. In addition, the width should be at least equal to the width of the lampholder 110b5 as in the above case.

Therefore, in view of the above, the insulation devices 110a7 and 110b7 according to the present invention have one lamp socket 110a5, 110a6, 110b5 and 110b6 and the lamp sockets which are configured on the balance PCBs 110a and 110b. The position and height of the insulating devices 110a7 and 110b7 may be changed depending on how the positive polarities 110a2 and 110b2 and the negative wirings 110a3 and 110b3 are formed with the 110a5, 110a6, 110b5 and 110b6 interposed therebetween. In other words, the present invention is a positive polarity (110a2, passing close to the lamp socket (110a5, 110a6, 110b5, 110b6) and the lamp socket (110a5, 110a6, 110b5, 110b6) to which the voltage of different polarity is applied. In order to secure the creepage distance and the clearance between the 110b2) and the negative wirings 110a3 and 110b3, the insulation devices 110a7 and 110b7 may be added.

4 (a) and 4 (b), the positive lamp socket 110b5 and the negative wiring 110b3 or the negative lamp socket 110a6 on the respective balance PCBs 110a and 110b. In the case of fastening the insulating devices 110a7 and 110b7 between the positive wiring 110a2 and the positive wiring, the distance measured via the surfaces of the insulating devices 110a7 and 110b7 becomes a creepage distance, while the insulating device 110a7 As mentioned above, the linear distance beyond 110b7) becomes the spatial distance.

In the present invention, when the space distance is based on the safety standard, such as US 60950, the left and right sides of the lamp sockets (110a6, 110b5) are required at least 8.4 mm each, so that the balance PCB (110a, 110b) of both sides, respectively It will occupy a minimum range of at least 16.8 mm.

Eventually such conditions are satisfied, while on the other hand, the positive lamp socket 110b5 and the negative wiring 110b3 or the negative lamp socket 110a6 and the positive wiring 110a2 on the balance PCBs 110a and 110b. Ramp sockets (110a5, 110a6, 110b5, 110b6) and voltage wiring (110a2, 110a3, 110b2, 110b3) on the balance PCBs 110a, 110b compared to the case where the insulation mechanisms 110a7, 110b7 are not fastened between them. The spacing between and, as a whole, to reduce the area of the balance PCB (110a, 110b).

On the other hand, the insulation mechanism according to the present invention does not form a slit on the lower cover 100 as shown in FIG. 5, but forms a slit only on the balance PCBs 110a and 110b, and the insulation mechanism 110a7 as the slit. , 110b7).

In this case, the insulating devices 110a7 and 110b7 are first fastened to the balance PCBs 110a and 110b, and then the balance PCBs 110a and 110b are provided on the lower cover 100 again.

At this time, the insulating mechanism (110a7, 110b7) is a groove with a step formed in the slit of the balance PCB (110a, 110b) formed by forming two lines on both sides, and the lower surface of the balance PCB (110, 110b) in which the slit is formed Since it is fastened to, the balance PCB (110a, 110b) on the lower cover 100 is thereby automatically maintained a balance (balance) without hardness to one side.

Except for this part, other contents are the same as the previous contents, so I will replace them.

As a result of the configuration up to now, the liquid crystal display according to the present invention eventually forms a high-voltage pattern and components on the conventional balance PCB, or additionally mounts components such as an inductor for more stable lamp driving. There is no need to increase the area of the substrate, which in turn can reduce the manufacturing cost. In addition, it is possible not only to secure safety by satisfying safety standards such as US 60950, but also to reduce the image realization range on the screen by eliminating the need to keep a wide bezel portion of the screen in the module process of the LCD. Can be prevented.

Claims (28)

A lower cover having a plurality of slits forming two lines on both sides thereof, and an odd-numbered slit and an even-numbered slit formed of different lines; Lamp fixing means for fixing the lamp, the lamp fixing means is provided on both sides on the lower cover, the voltage is provided to the lamp fixing means alternately provided with two voltages having opposite polarities, respectively formed in the edge region with the lamp fixing means therebetween; A balance printed circuit board (PCB) formed between a wiring and the lamp fixing means and the voltage wiring and including a slit corresponding to a slit on the lower cover; Insulation mechanism is fastened to the slit of the balance PCB through the slit of the lower cover, to secure the creepage and clearance distance while reducing the distance between the lamp fixing means and the voltage wiring; And And a liquid crystal panel receiving light from the lamp. The liquid crystal display of claim 1, wherein the lamp is a CCFL. 2. The liquid crystal display device according to claim 1, wherein when the insulating device is formed at the lower end of the lamp, its height is formed within a height between the reflecting plate and the lower end of the lamp. The liquid crystal display device according to claim 1, wherein the width of the insulating device is at least equal to the width of the lamp fixing means. 2. A liquid crystal display device as claimed in claim 1, wherein when the insulating mechanism is formed on the opposite side of the lamp fixing means to which the lamp is fastened, its height is formed to be greater than or equal to the height of the lamp fixing means. The liquid crystal display device according to claim 1, wherein the insulation mechanism is formed of a poly resin. The liquid crystal display device according to claim 1, wherein the clearance distance from the lamp fixing means to the voltage wiring in proximity to the upper surface of the insulating device is at least 8.4 mm. A lower cover having a plurality of slits forming two lines on both sides thereof, and an odd-numbered slit and an even-numbered slit formed of different lines; Lamp fixing means for fixing the lamp, the lamp fixing means is provided on both sides on the lower cover, the voltage is provided to the lamp fixing means alternately provided with two voltages having opposite polarities, respectively formed in the edge region with the lamp fixing means therebetween; A balance PCB formed between a wiring and the lamp fixing means and the voltage wiring and including a slit corresponding to a slit on the lower cover; Insulation mechanism is fastened to the slit of the balance PCB through the slit of the lower cover, to secure the creepage and clearance distance while reducing the distance between the lamp fixing means and the voltage wiring; A lamp fastened to the lamp fixing means to provide light; And And a side support provided on the balance PCB to protect the electrode of the lamp. The backlight device of claim 8, wherein the lamp is a CCFL. The backlight device according to claim 8, wherein when the insulating device is formed at the lower end of the lamp, the height thereof is formed within a height between the reflecting plate and the lower end of the lamp. 9. The backlight device of claim 8, wherein the width of the insulating device is at least equal to the width of the lamp fixing means. 10. The backlight device according to claim 8, wherein when the insulating mechanism is formed on the opposite side of the lamp fixing means to which the lamp is fastened, its height is formed to be equal to or greater than the height of the lamp fixing means. The backlight device of claim 8, wherein the insulation device is formed of a poly resin. 9. The backlight device of a liquid crystal display device according to claim 8, wherein a linear space distance from the lamp fixing means to a voltage wiring in proximity to the upper surface of the insulating mechanism is at least 8.4 mm. Lower cover; Lamp fixing means for fixing the lamp, the lamp fixing means is provided on both sides on the lower cover, the voltage is provided to the lamp fixing means alternately provided with two voltages having opposite polarities, respectively formed in the edge region with the lamp fixing means therebetween; A balance PCB fastened to wiring, a slit formed between the lamp fixing means and the voltage wiring, and the slit, the balance PCB having an insulation mechanism formed to secure a creepage and a clearance while reducing a distance between the lamp fixing means and the voltage wiring; And And a liquid crystal panel receiving light from the lamp. The liquid crystal display of claim 15, wherein the lamp is a CCFL. 16. The liquid crystal display device according to claim 15, wherein when the insulating device is formed at the lower end of the lamp, the height thereof is formed within a height between the reflecting plate and the lower end of the lamp. The liquid crystal display device according to claim 15, wherein the width of the insulating device is at least equal to the width of the lamp fixing means. 16. The liquid crystal display device according to claim 15, wherein when the insulating mechanism is formed on the opposite side of the lamp fixing means to which the lamp is fastened, the height thereof is formed to be equal to or greater than the height of the lamp fixing means. 16. The liquid crystal display device according to claim 15, wherein the insulation mechanism is made of poly resin. 16. The liquid crystal display device according to claim 15, wherein the clearance distance from said lamp fixing means to the adjacent voltage wiring via said insulating mechanism is at least 8.4 mm. Lower cover; Lamp fixing means for fixing the lamp, the lamp fixing means is provided on both sides on the lower cover, the voltage is provided to the lamp fixing means alternately provided with two voltages having opposite polarities, respectively formed in the edge region with the lamp fixing means therebetween; A balance PCB fastened to wiring, a slit formed between the lamp fixing means and the voltage wiring, and the slit, the balance PCB having an insulation mechanism formed to secure a creepage and a clearance while reducing a distance between the lamp fixing means and the voltage wiring; A lamp fastened to the lamp fixing means to provide light; And And a side support provided on the balance PCB to protect the electrode of the lamp. 23. The backlight device of claim 22, wherein the lamp is CCFL. 23. The backlight device according to claim 22, wherein when the insulating device is formed at the lower end of the lamp, its height is formed within a height between the reflecting plate and the lower end of the lamp. 23. The backlight device of claim 22, wherein the width of the insulating device is at least equal to the width of the lamp fixing means. 23. The backlight device according to claim 22, wherein when the insulation mechanism is formed on the opposite side of the lamp fixing means to which the lamp is fastened, the height thereof is formed to be equal to or greater than the height of the lamp fixing means. 23. The backlight device according to claim 22, wherein the insulation mechanism is formed of a poly resin. 23. The backlight device according to claim 22, wherein the clearance distance from said lamp fixing means to a voltage wiring in proximity to said insulating device is at least 8.4 mm.

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