KR101404650B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device for flexibly responding to an environment in which different color reproduction ratios are required, such as a moving picture or a document operation, which is implemented on a screen of a liquid crystal display device. A signal applying means for generating a control signal for driving the liquid crystal panel; Wherein at least one of the first group of light emitting means arranged in red (R), green (G), and blue (B) and the second group of light emitting means arranged in white (W) A backlight device for driving the display device; And a backlight driving means for receiving and outputting at least one power source (power source) for driving the first and second groups of light emitting means by receiving a control signal from the signal applying means.

Color reproduction ratio, light emitting means, LED (Light Emitting Diode)

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

1 is an exploded perspective view of a direct-type liquid crystal display device according to the related art.

Fig. 2 is a plan view showing a method of arranging the light emitting means of Fig.

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

Fig. 4 is a plan view showing a method of arranging the light emitting means of Fig. 3

Fig. 5 is a plan view showing a light emitting means according to another embodiment of Fig. 4

6 is a block diagram showing a driving method of the backlight device of FIG.

7 is an exploded perspective view of an edge type liquid crystal display device according to the present invention

8 is a plan view showing a method of arranging the light emitting means of Fig. 7

Fig. 9 is a plan view showing the light emitting means according to another embodiment of Fig. 8

10 is a block diagram showing a driving method of the backlight device of FIG.

DESCRIPTION OF REFERENCE NUMERALS

300: Power supply voltage generation unit 310: Timing controller

320: Backlight driver 320a: R, G, B driver

320b: W driver 320c:

330: backlight device 330a: first group light emitting means

330b: the second group of light emitting means

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device in which a backlight structure such as an LED is modified to flexibly cope with an environment in which different color recalling ratios are required, And the like.

BACKGROUND ART A direct type back-light used in a liquid crystal display of a large-sized model generally reflects light from a cold cathode fluorescent lamp to a liquid crystal panel on the front side from a reflector. In addition, a milky white scattering plate is disposed in the reflection path of the light, and locally light having a uniform illuminance is used to illuminate the liquid crystal display. However, such a method has a problem that the liquid crystal display is brought to a complicated large model due to problems such as the backlight thickness of the display.

In recent years, as a surface light source device, a backlight is thinned by using an LED (Light Emitting Diode) having characteristics of fast response speed, low power consumption and semi-permanent lifetime as a bipolar device that emits light only when a current passes therethrough At the same time, the brightness is improved. Above all, it is possible to reproduce images of natural color and high quality compared with conventional cold cathode tubes, and to solve the afterimage problem of moving images and recognize that it is an environmentally friendly product that does not use mercury. It is no longer a key component.

Hereinafter, a liquid crystal display device having a conventional direct-type LED backlight device will be described with reference to the drawings. As shown in FIG. 1, the liquid crystal display device has a main support 50 made of synthetic resin or SUS STEEL having a substantially rectangular frame shape as a reference, and a backlight device (not shown) (Unrepresented), and the liquid crystal panel 10 is stacked and fastened in the upper part. An upper cover 60 capable of fixing both covers the front edge of the liquid crystal panel 10 and is assembled and fastened to the main support 50 and the lower cover 30.

First, in the case of a direct-type LED backlight for providing light to the liquid crystal panel, an LED array 36 formed of at least one line of LEDs mounted on the lower cover 40 and emitting light, A plurality of PCBs (Printed Circuit Boards) 34 provided on the front surface of the PCB 34 and lighting the LED arrays 36 while being driven up and down; A diffusion plate 42 provided on the LED array 36 to reduce nonuniformity of light generated from the LED array 36 and a protective sheet 42 for protecting the prism sheet 44 and increasing the viewing angle, 46).

As shown in the drawing, a reflector 32 formed on a lower front surface of a region where the PCB 34 is driven, and an LED array 36 formed of at least one line, And a reflector 38 formed on a printed circuit board 34 of a printed circuit board 34. The reflector 38 formed on one printed circuit board 34 forms a hole in the LED area, It is a little different. The reflection plates 32 and 38 are usually formed by coating a white polyester film with a reflective film such as a metal (Ag, Al) or the like. In some cases, a silicon oxide (SiO ₂ ) Scattering particles are mixed and cured.

When the backlight device is completed, a main support 50 made of a synthetic resin or a steel material having a substantially rectangular frame shape is fastened, and then the liquid crystal panel 10 is mounted on the upper side. Of course, the liquid crystal panel 10 here is composed of a thin film transistor array substrate and a color filter substrate bonded together, and liquid crystal injected therebetween.

2 is a plan view showing a plurality of PCBs arranged and fixed on the lower cover 30 as shown in FIG. Conventionally, a PCB array 34 of about eight is used in the case of a 32-inch LCD display, and the heat of the high temperature associated with the LEDs 36 fixed on the PCB 34 There is a tendency to use a metal PCB 34 formed with a separate metal material on the back surface of the PCB 34 due to an occurrence problem. Although not shown in the drawing, the metal PCB 34 is fixed on a metal bar such as aluminum and fastened on the lower cover 30.

In a liquid crystal display device constituted by applying red (R), green (G) and blue (B) LEDs 34 on a single metal PCB 34 as a backlight structure, It is possible to realize a color reproduction rate close to 90% at the time of implementing a moving picture. However, even if the color reproduction rate is not required as in the document operation, R , G, and B LEDs 34 are combined to emit color, power consumption may be increased. In addition, the user may suffer from fatigue of eyes due to a long time of work .

Therefore, in order to solve such a problem, the present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a metal PCB having RGB array LEDs for use in a high color reproduction rate, It is an object of the present invention to provide a metal PCB having LEDs arranged in a WWWW array for use in an excellent column, or to drive a liquid crystal display device by appropriately modifying the metal PCB.

And achieving such an object can be further embodied by the present invention. That is, a liquid crystal display device according to the present invention includes: a liquid crystal panel that implements an image; A signal applying means for generating a control signal for driving the liquid crystal panel; Wherein at least one of the first group of light emitting means arranged in red (R), green (G), and blue (B) and the second group of light emitting means arranged in white (W) A backlight device for driving the display device; And a backlight driving means for receiving and outputting at least one power source (power source) for driving the first and second groups of light emitting means by receiving a control signal from the signal applying means.

Hereinafter, the configuration will be described in detail with reference to FIGS. 3 and 4. FIG. FIG. 3 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention, and FIG. 4 is a view illustrating a backlight structure of FIG.

As shown in the figure, a direct-type LED backlight device for providing light to the liquid crystal panel is first fastened on the lower cover 130. A reflector covering the front surface is attached to the lower cover 130 . This is referred to as a first reflector (unrepresented) in the present invention.

A plurality of metal PCBs 132 and 136 are formed in a string on a lower cover 130 to which a first reflector (unrepresented) is attached. RGB LEDs 134a, 134b and 134c of red (R), green (G) and blue (B) are arranged on the odd-numbered metal PCB 132 such as the first row and the third row, And the LEDs 138a, 138b, and 138c of the back (W) are formed on the metal PCB 136 of the even number, such as the second row and the fourth row, WWWWWWWWWW ...... WWW "are formed. Of course, in the opposite case, a second group of light emitting means 138 is formed on the odd-numbered metal PCB 132 and a first group of light emitting means 134 is formed on the even-numbered metal PCB 136 May be possible.

Here, the metal PCBs 132 and 136 are formed of a metal bar, and the front surface where the LEDs 138a, 138b and 138c of R, G and B 134a, 134b and 134c and W are formed, A conductive pattern for driving the LED is formed and a separate metal material is formed on the back surface of the conductive pattern due to heat generation at a high temperature related to the LED.

Further, another reflection plate is attached on one of the metal PCs 132 and 136. [ Unlike the first reflector (unrepresented), they are attached to each of the metal PCBs 132 and 136 constituted in series, and therefore, they are different from each other in size. Accordingly, in the present invention, such a reflector attached on the metal PCBs 132 and 136 provided in series is called a second reflector (unrepresented).

An upper portion of the plurality of metal PCBs 132 and 136 having the LEDs formed thereon as an array includes a diffusion plate 141 and a diffusion sheet 142 for relieving unevenness of light emitted from the LEDs 134 and 138 And a protective sheet 146 for protecting the prism sheet 144 and the prism sheet 144 that increase the brightness of light transmitted through the diffusion plate 141 and the diffusion sheet 142 and increase the viewing angle.

Then, the main support 150 is fastened to maintain the overall force balance of the liquid crystal display device. A certain pattern is formed for the liquid crystal panel 110 on the upper side as a mold of a synthetic resin or SUS STEEL having a substantially rectangular frame shape and surrounds the outer periphery of the lower cover 130 as shown in the figure Respectively.

On the main support 150, a liquid crystal panel 110 for receiving data from the outside and receiving light from a lower backlight is mounted. Of course, the liquid crystal panel 110 includes a thin film transistor array substrate in which thin film transistors, which are switching elements, are arranged for each unit pixel, a color filter substrate on which a color filter expressing color is formed, .

An upper cover 160 capable of fixing all of these covers the four sides of the liquid crystal panel 110 and is assembled and fastened to the main support 150 and the lower cover 130.

In the configuration up to now, the backlight structure of the direct type liquid crystal display device of the present invention as shown in Fig. 4 can be changed by the backlight structure of Fig. 5 as much as possible. In other words, since the metal PCBs 232 and 236 are arranged in a plurality of rows as in the first and second columns on the lower cover 230, the odd-numbered and even-numbered metal PCBs 232 and 236, It is also provided in plural.

In this case, LEDs 234a, 234b, and 234c of red (R), green (G), and blue (B) are arranged in "RGBRGB ...... RGB" on the odd- And the LEDs 238a, 238b and 238c of the bag W are arranged in the WWWWWWWWWW ... WWW on the metal PCB 236 of the first row in the first row, Emitting means 238 of the group are formed.

On the other hand, on the odd-numbered metal PCB 236 of the second row, the second group of light emitting means 238 in which the LEDs 238a, 238b and 238c of the white W are arranged in "WWWWWWWWWW ... WWW" On the metal PCB 232 of the second row in the second row, LEDs 234a, 234b and 234c of red (R), green (G) and blue (B) The first group 234 and the second group of light emitting means 238 on the lower cover 230 are provided in a zig-zag form by forming the means 234.

Accordingly, when the metal PCBs 232 and 236 are arranged in a plurality of rows, the odd-numbered columns of the first column and the odd-numbered columns of the third column, and the odd-numbered columns of the odd- It is preferable that the first group 234 and the second group of light emitting means 238 are alternately formed for each row and each row.

In the direct type liquid crystal display device using such an LED backlight structure, the color reproduction rate can be varied by user's mode selection and program selection.

In other words, when a high luminance is required, the first group 234 arranged in "RGBRGB ...... RGB" and the second group 238 arranged in "WWWWW ... WWW" are all turned on The color reproduction ratio of about 75% can be realized.

Further, when a moving image is realized on the screen of the liquid crystal panel, a high color is required. Therefore, by only turning on the first group of light emitting means 234 arranged in "RGBRGB ...... RGB & .

On the other hand, when a high color reproduction rate is not required as in document processing, only the second group of light emitting means 238 arranged in "WWWWWW ...... WWW"

6 is a block diagram showing a driving method of the direct-type backlight device. Referring to FIG. 2, a timing controller 310, which forms a main driving unit on a main PCB in a liquid crystal display, receives R, G, and B data from outside and vertical and horizontal synchronizing signals to rearrange data, A new control signal is generated to drive the control signal.

In addition, the timing controller 310 constitutes a separate comparison means (not shown) inside or outside to compute chrominance information (Cb, Cr) and luminance information (Cb, Cr) of image data input from the outside in units of a macro block Y, and generates a bit signal from a bit assigning means (not shown) according to the image information, and sends the bit signal to the backlight driving unit 320 for driving the LED backlight unit 330.

Of course, the timing controller 310 and the backlight driver 320 receive a voltage from a separate power supply voltage generator 300. The timing controller 310 uses a voltage in a range of about 3.3 V to 5 V And generates a new control signal for controlling the gate and data driver (not shown) by pumping up or pumping down the voltage.

The backlight driving unit 320 receives the voltage from the power supply voltage generating unit 300 and generates a voltage for driving the light emitting unit of the backlight unit 330. For example, as in the present invention, the first group of light emitting means 330a including the backlight unit 330 arranged in R, G and B and the second group of light emitting means 330b arranged in the W The backlight driver 320 is divided into a separate R, G, and B drivers 320a and a W driver 320b because the range of the current or voltage to be driven is different. The current or voltage formed by such a configuration is selected by the switching unit 320c that is configured and linked with the output side, and is output to the backlight unit 330. [

For example, when it is assumed that the R, G, and B driving units 320a and the W driving units 320b are formed of 2-bit signals and are controlled to 4 bits in such a configuration, the comparison means (not shown) in the timing controller 310 (Cb, Cr) and luminance information (Y) of the image data that are input first in the input image data. When it is determined that a relatively high color reproduction rate is required as in the moving image, a bit signal for driving the R, G, and B driving units 320a is supplied to the switching unit 320 The corresponding current or voltage is outputted from the R, G, and B driving unit 320a to the backlight unit 330. [0050] As a result, the first group of light emitting means 330a provided in the backlight unit 330 is driven.

On the other hand, when the color difference information (Cb, Cr) and the luminance information (Y) of the image data input from the comparison means (not shown) in the timing controller 310 are detected and compared, a comparatively high color reproduction rate If it is determined as an image, a bit signal for driving the W driving unit 320b is supplied to a switching unit 320 and a corresponding switch is turned on in a bit giving unit (not shown). Then, the W driving unit 320b And the corresponding current or voltage is output to the backlight device 330. [ As a result, the second group of light emitting units 330b included in the backlight unit 330 are driven.

Meanwhile, the configuration according to one embodiment of the present invention described so far can be applied to an edge type LED liquid crystal display device as much as possible. 7 is an exploded perspective view of a liquid crystal display device according to another embodiment of the present invention. A reflector 421 for reflecting light emitted from a light emitting device such as an LED to the front liquid crystal panel 440 is attached on the lower cover 410, The LEDs are arranged at regular intervals, and the fixed metal PCB 420 and the light guide plate 424 are sequentially stacked.

Of course, the metal PCB 420 is adhered to the inside of a surface bent upward from both side edges of the lower cover 310. Positive (+) and negative (-) electrode portions on the metal PCB 420 For example, holes are formed at both side edges of the bottom surface of the lower cover 410 to receive power from the outside.

In the present invention, the metal PCB 420, which is provided at both side edge regions of the lower cover 40, includes LEDs having different arrangements. In other words, if a first group of LEDs, in which the metal PCB 420a provided as one edge region of the lower cover 310 is arranged in the above-mentioned "RGBRGB ...... RGB", are formed, And a second group of LEDs arranged in "WWWWWW ... WWW"

The metal PCB 420 having the LEDs formed thereon is attached to the side surface of the lower cover 410 so that the light emitting portion is directed to the light guide plate 424, so that the emitted light naturally flows into the light guide plate 424.

The optical sheets 426 and 428 are stacked on the metal PCB 420 attached to the lower cover 410 and the light guide plate 424. The efficiency of light emitted from the reflection plate 421 and the light guide plate 424 Two diffusion sheets 426 and a protective sheet 428 are provided for each liquid crystal panel 440.

Meanwhile, a panel guide 430 of a frame mold material is fastened to the outer periphery of the lower cover 410 to keep the overall force balance of the liquid crystal display device and to separate the liquid crystal panel 440 by a predetermined distance.

A liquid crystal panel 440 for realizing an image is mounted on the panel guide 430. The detailed structure of the liquid crystal panel 440 includes a thin film transistor array substrate and a color filter substrate bonded together so as to maintain a uniform cell- And liquid crystal injected between the two substrates.

The upper cover 450 having a rectangular frame shape covering the edge of the liquid crystal panel 440 is assembled and fastened to the panel guide 430 to complete the liquid crystal display device.

Here, the edge type backlight structure shown in Fig. 7 can also be changed to Fig. 8 and Fig. First, as shown in FIG. 8, a first group of light emitting means and a second group of light emitting means are arranged on a plurality of metal PCBs 520 provided on one side of the lower cover 510 in the form of "RGBRGB ...... RGB", and "WWWWWW ...... WWW" And the other side of the lower cover 410 corresponds to the first and second groups of light emitting means on one side of the lower cover 410. The light emitting means of the first group and the second group Means can be formed.

However, a first group of light emitting means and a second group of light emitting means, which are respectively arranged in "RGBRGB ...... RGB" on a plurality of metal PCBs 620 provided on one side of the lower cover 610 in Fig. 9 and "WWWWWW ... WWW" And the other side of the lower cover 610 corresponds to the first and second groups of light emitting means of the first group and the second group of light emitting means of the second group, May be formed.

Of course, the edge type liquid crystal display device configured in this manner can also change the color reproduction rate by selecting the mode of the user as in the case of the direct-type liquid crystal display device.

In other words, when a high luminance is required, the first group of the "RGBRGB ...... RGB" array provided on both sides of the lower cover 410, 510, 610 and the second group of the second group of the "WWWWWW ...... WWW" By turning on the means, a color reproduction rate of about 75% can be realized.

Further, when a moving image is implemented on the screen of the liquid crystal panel 350, a high color is required. Therefore, the first group of the RGBRGB ...... RGB array in one side of the lower covers 410, 510, By turning on only the means, a color reproduction rate close to 100% can be realized.

On the other hand, when a high color reproduction rate is not required, such as a document operation, only the second group of light emitting means of the WWWWW WW WWW arrangement arranged on one side or both sides of the lower covers 410, 510, Level color reproduction rate can be realized.

10 is a block diagram showing a driving method of such an edge type backlight device. In the drawing, the timing controller 710 receives R, G, and B data and external vertical and horizontal synchronizing signals from the outside, rearranges the data, and generates a new control signal for driving the liquid crystal panel (not shown) do.

In addition, in the liquid crystal display device, a separate comparison means (not shown) is provided inside or outside the timing controller 710, which constitutes the main driving unit on the main PCB, so that image data in units of a macro block input from the outside (Cb, Cr) and luminance information (Y) of the LED backlight unit 730. Then, the LED backlight unit 730 is driven by generating a bit signal from a separate bit- To the backlight driver 720. [

Of course, the timing controller 710 and the backlight driving unit 720 receive a voltage from a separate power supply voltage generator 700, and the timing controller 710 outputs a voltage in a range of approximately 3.3V to 5V And generates a new control signal for controlling the gate and data driver (not shown) by pumping up or down the voltage.

The backlight driving unit 720 receives the voltage from the power supply voltage generating unit 700 and generates a voltage for driving the light emitting unit of the backlight unit 730. For example, as in the present invention, the first group of light emitting means 730a and the second group of light emitting means 730b, which are arranged in the form of W, in which the backlight device 730 is arranged in R, G, G, B driving unit 720a and the W driving unit 720b in the backlight driving unit 720 because the range of the driving current or voltage is different. The current or voltage formed by such a configuration is selected by the switching unit 720c, which is configured on the output side and is interlocked, and is output to the backlight unit 730. [

(Not shown) in the timing controller 710, assuming that the R, G, B driver 720a and the W driver 720b are formed of 2-bit signals and controlled to 4 bits in such a configuration, (Cb, Cr) and luminance information (Y) of the image data to be input first. Then, when it is determined that the image requires a relatively high color reproduction rate such as a moving image, a bit signal for driving the R, G, and B driver 720a is applied to the switching unit 720 The corresponding current or voltage is outputted from the R, G, and B driver 720a to the backlight device 730. [0157] As a result, the first group of light emitting means 730a provided in the backlight unit 730 is driven.

On the other hand, when the color difference information (Cb, Cr) and the luminance information (Y) of the image data input from the comparison means (not shown) in the timing controller 710 are detected and compared, a comparatively high color reproduction rate If it is determined as an image, a bit signal for driving the W driver 720b is supplied to a switching unit 720 and a corresponding switch is turned on in a bit giving unit (not shown), and the W driver 720b And the corresponding current or voltage is output to the backlight device 730. As a result, the second group of light emitting units 730b provided in the backlight unit 730 are driven.

Of course, according to the embodiment of the present invention described so far, the first group of light emitting means arranged in "RGBRGB ...... RGB ", for example, LEDs of R, G and B are mixed On the other hand, the LEDs of R, G, and B may be formed of a single cluster on the metal PCBs 320, 420, and 520 as a silicon material to generate white light. There is.

In addition, according to the embodiment of the present invention described so far, the first group of light emitting means arranged in "RGBRGB ...... RGB" can be formed of "RGGBRGGB ...... RGGB & .

As a result of the above configuration, the liquid crystal display according to the present invention can drive the corresponding light emitting means according to the user's selection, thereby reducing the power consumption of the light emitting means when the high color reproduction rate is not required In addition, from the viewpoint of the user, it will be possible to reduce fatigue of eyes due to a long working time.

Claims (17)

A liquid crystal panel for realizing an image; A signal applying means for generating a control signal for driving the liquid crystal panel according to input image data; Wherein at least one of the first group of light emitting means arranged in red (R), green (G), and blue (B) and the second group of light emitting means arranged in white (W) A driving backlight device; And a backlight driving unit for receiving at least one of the first and second groups of light emitting units and receiving the control signal from the signal application unit, Wherein the backlight driving unit selects and outputs a power source capable of driving the first group of light emitting units of the backlight unit if the control signal is a moving image signal, And a power source capable of driving the second group of light emitting means of the apparatus is selected and output. The liquid crystal display according to claim 1, wherein the signal applying means comprises data driving means for supplying data to a data line of the liquid crystal panel; Gate driving means for supplying a gate pulse to the gate line of the liquid crystal panel; And a controller for receiving the R, G, and B data from the outside and comparing the color difference and the luminance information to generate a control signal for selecting the light emitting unit, receiving the vertical and horizontal synchronizing signals from the outside, And a timing controller for generating a new control signal to be applied to the liquid crystal display panel. The liquid crystal display device according to claim 1, wherein the light emitting means is an LED (Light Emitting Diode). The liquid crystal display device according to claim 1, wherein the first and second groups of light emitting means are arranged and fixed on a metal printed circuit board. The liquid crystal display of claim 1, wherein the power source is a current source or a voltage source. 2. The backlight unit according to claim 1, RGB driving means for driving the first group of light emitting means; A W drive means for driving the second group of light emitting means; And switching means for selecting and driving at least one of the RGB driving means and the W driving means by receiving the control signal from the signal applying means. delete delete The liquid crystal display of claim 1, wherein when the control signal of the signal applying means is a signal indicating an image of a high luminance, the backlight device simultaneously drives the first and second groups of light emitting means. The backlight unit according to claim 1, wherein, when the light emitting means is fixed to the metal PCB and is provided in a plurality of series, the odd-numbered light emitting means of the first group is the light emitting means of the first group, Are arranged in the liquid crystal display panel. 2. The backlight unit according to claim 1, wherein when the light emitting means is fixed to the metal PCB and includes a plurality of light emitting units arranged in series, the odd-numbered light emitting units are alternately formed in the first and second light emitting units, And the second group and the first group of light emitting means are alternately formed to form a zig-zag shape. 2. The backlight unit according to claim 1, wherein when the light emitting means is fixed to the metal PCB and is provided in a plurality of series, the odd-numbered ones are alternately formed between the second group and the first group of light emitting means, Wherein the first and second groups of light emitting means are alternately formed in a zig-zag shape. The backlight unit according to claim 1, wherein the light emitting means is fixed to the metal PCB and is provided on both sides, the first group of light emitting means is formed on one side and the second group of light emitting means is formed on the other side Wherein the liquid crystal display device is a liquid crystal display device. 2. The backlight unit of claim 1, wherein when the light emitting means is fixed to the metal PCB and is provided on both sides, the first group and the second group of light emitting means are alternately formed on one side, And the second group of light emitting means are alternately formed. 15. The liquid crystal display device according to claim 14, wherein the first group of light emitting means located at one side and the first group of light emitting means located at the other side are formed corresponding to each other. 2. The backlight unit of claim 1, wherein when the light emitting means is fixed to the metal PCB and is provided on both sides, the first group and the second group of light emitting means are alternately formed on one side, And the group of light emitting means are alternately formed. The liquid crystal display device according to claim 16, wherein the first group of light emitting means located at one side and the first group of light emitting means located at the other side are formed diagonally to each other.

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