KR100840769B1 - Backlight device of liquid crystal display - Google Patents

Abstract

According to the present invention, a light guide plate applied to a backlight device applied to a large screen liquid crystal display device includes a plurality of bent portions formed at both ends or four ends thereof, and a light source is placed at the formed bent portions of the multi stage liquid crystal display to increase the luminance of the large liquid crystal display device. The present invention relates to a backlight device of a liquid crystal display device having a large brightness and a uniform brightness, wherein the backlight device has a quadrangular bent portion (12) at both ends or all four corners in a square shape. Light guide plate 10 is formed; A light supply unit 20 provided at the bent portion 12 of the multi-stage so that light is incident on the light guide plate 10 horizontally; And a reflector 30 provided on a surface on which the light supply unit 20 is not provided, wherein the light supply unit 20 is a light source attached to and fixed to the PCB substrate 22 and the PCB substrate 22. Characterized in that (24).

LCD, backlight, LGP, multi-stage, bend, LED module, lamp

Description

Backlight device of liquid crystal display device {BACKLIGHT APPARATUS OF LIQUID DISPLAY APPARATUS}

1 is an exploded perspective view of a liquid crystal display according to the prior art.

2 is a front view of a backlight unit of the liquid crystal display according to the present invention.

3 is a bottom view of FIG. 2.

4 is a partial perspective view of FIG. 2.

5 is another embodiment of FIG. 2.

6 is another embodiment of FIG. 2.

FIG. 7 is a view for explaining the assembled state as another embodiment of FIG. 4.

8 is another embodiment of FIG.

9 is a view showing a state in which the light source is applied to the lamp instead of the light emitting diode module in the embodiment of FIG.

10 is a bottom view of FIG. 9.

11 is another embodiment of FIG. 10.

12 is a partial perspective view of FIG. 9.

13 to 17 illustrate embodiments of a light guide plate applied to the present invention.

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

19 is another embodiment of FIG. 18.

*** Explanation of symbols on main parts of drawing ***

10: light guide plate

12: bend

20: light supply unit

22: PCB board

24: light source

30: reflector

40: light sheet

The present invention relates to a backlight device of a liquid crystal display device.

More specifically, in a light guide plate applied to a backlight device applied to a large screen liquid crystal display device, multiple bent portions are formed at both ends or all four ends, and a light source is placed at the bent portions formed at the multi stages, so that The present invention relates to a backlight device of a liquid crystal display device having a uniform brightness while greatly improving the brightness.

In general, a liquid crystal display device forms transparent electrodes on two glass substrates, forms RGB pixels on one glass substrate, and simultaneously applies a predetermined voltage to the transparent electrode, and transparent formed on the other glass substrate. After forming a thin film transistor on the electrode and applying a predetermined voltage only by the turn-on of the thin film transistor, a liquid crystal display panel is formed by injecting a liquid crystal whose light transmittance is changed by an electric field between two glass substrates. The desired image is displayed by driving the display panel by the driving device.

Such a liquid crystal display device does not operate without light, so a backlight device is necessary to drive the liquid crystal display device.

Recently, large screen liquid crystal display panels, such as LCD monitors and LCD TVs, have been developed as large screens of the liquid crystal display device having the liquid crystal display panel and the backlight device described above have been greatly demanded.

The liquid crystal display device is used not only as a display device of a portable computer but also as a display device of a desktop computer, and is also used as a display device of various devices throughout the industry.

However, even if the LCD is gradually enlarged as described above, the increase in the thickness of the LCD panel, which is an essential component of the LCD, does not occur much. However, as the screen of the LCD becomes larger, the size of the backlight device increases in proportion. And the thickness is greatly increased.

As the liquid crystal display becomes larger, the size and thickness of the backlight are increased due to an increase in the area of the light guide plate, which is inevitably increased in proportion to the screen size of the liquid crystal display.

That is, as the planar area of the LGP increases, the thickness of the incident surface of the LGP is unavoidably increased in order to prevent luminance deterioration and luminance unevenness of the LCD. The problem arises that the size and thickness must be increased, resulting in a result contrary to the purpose of the liquid crystal display device in pursuit of slimmer and lighter weight.

The light guide plate according to the related art implemented to solve the above problems is shown in FIG. 1, and the light guide plate will be described with reference to FIG. 1 while explaining a liquid crystal display device to which the light guide plate according to the prior art is applied. Is as follows.

As shown in FIG. 1, the liquid crystal display 801 according to the prior art generally includes a display unit 100, a backlight device 600, and a chassis 700.

The display unit 100 is again composed of a printed circuit board 3 including a liquid crystal display panel 1, a tape carrier package 2, and a driving signal generator (not shown).

The backlight device 600 includes a light supply unit group 200, a storage container 300, a diffusion sheet 400, and a display unit fixing cover 500.

The light supply unit group 200 is again composed of a plurality of light supply units 150.

At this time, each light supply unit 150 is composed of a combination of the light guide plate 110 and the lamp unit 130 again.

In one embodiment, the light guide plate 110 is a wedge type in which the thickness becomes thinner gradually from one end to the other end in a square shape, and the side surface corresponding to the thickest part of the light guide plate 110 becomes the light incident surface 112. The upper edge of the light incident surface 112 is processed so that the stepped 114 is formed. That is, the light guide plate 110 includes a rectangular parallelepiped, a cube, and the like, and depends on the shape of the LCD.

In addition, protrusions protruding a predetermined length from both side surfaces are formed on both side surfaces perpendicular to the light incident surface of the light guide plate 110.

The protrusion is preferably processed into a hexahedral shape, the protrusion is coupled to the storage container 300 to be described later is a flow preventing protrusion 119 which serves to prevent unnecessary flow of the light guide plate 110.

On the other hand, a reflective material (or reflective dot; not shown) is formed on the inclined bottom surface of the light guide plate 110 by a silkscreen printing method.

The lamp unit 130 includes a lamp cover 132 having a “c” shape and a lamp 134. The lamp cover 132 on which the lamp 134 is mounted has a light incident surface of the light guide plate 110 described above. (112) The bottom surface is fixed by various methods such as adhesive or adhesive sheet.

As such, the light supply unit 150 including the light guide plate 110 and the lamp unit 130 is coupled to at least two or more to form the light supply unit group 200 as shown in FIG. 1. The light source unit 200 may be manufactured by mounting an end portion 112a of the light supply unit 150 opposite to the light incident surface 112 at an end formed at an upper end of the light guide plate of the other light supply unit.

The light supply unit group 200 as described above is mounted on the upper surface of the reflecting plate 210 in a state in which the reflecting plate 210 is seated on the receiving container 300.

Such a backlight device has an advantage that the thickness of the liquid crystal display device does not increase even when the liquid crystal display device is made large, but a plurality of light guide plates are connected in parallel, thereby causing the line of the connection portion to appear on the screen.

In addition, the backlight device of the prior art also has a problem that the color of the screen is different from each other by the color coordinates of the lamp.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is a light guide plate applied to a backlight device applied to a large-screen liquid crystal display device, both ends or all four ends of the bent portion The present invention provides a backlight device of a liquid crystal display device having a uniform brightness while greatly increasing the brightness of a large screen liquid crystal display device by placing a light source at a bent portion of the formed multi-stage.

One embodiment of the present invention proposed in order to solve the above technical problem, in the backlight device of the liquid crystal display device, the backlight device has a quadrangular bent portion 12 at both ends or all four ends in a square shape; Light guide plate 10 is formed; A light supply unit 20 provided at the bent portion 12 of the multi-stage so that light is incident on the light guide plate 10 horizontally; And a reflector plate 30 provided on a surface on which the light supply unit 20 is not provided. The light supply unit 20 includes a light source 24 to which an LED is attached and fixed to the PCB substrate 22. It is characterized by.

Hereinafter, a backlight device of a liquid crystal display device will be described in detail with reference to the accompanying drawings.

( Example 1 )

One embodiment of the backlight device according to the present invention includes a light guide plate 10 having a plurality of bent portions 12 are formed at both ends or all four ends in a square shape as shown in FIGS. 2 and 3. And a light supply unit 20 provided at the bent portion 12 of the multi-stage so that light is incident on the light guide plate 10 horizontally, and a reflector plate 30 provided below the light guide plate 10 and above the storage container. ). The reflective plate 30 is provided inside the storage container 290.

The light supply unit 20 includes a PCB substrate 22 and a light source 24 spaced apart from and fixed to the PCB substrate 22 at fixed intervals. At this time, the light source 24 is an LED.

At this time, the light guide plate 10 is formed in a symmetrical shape on both sides from the center, the light guide plate 10 is a fixing projection (C) is formed on each corner of the upper surface as shown in FIG. In particular, the fixing projections C may be formed at any position horizontally or vertically, and only need to fix the light sheet 400 to the light guide plate 10. That is, the fixing protrusion C is coupled to the coupling hole H formed in the light sheet 400 and the light sheet 400 is coupled to the light guide plate 10 to be fixed.
In this case, the bent portion space should be equal to or deeper than the thickness of the light sheet 400.

delete

Meanwhile, when the dark line is not completely removed when the backlight device is configured as shown in FIG. 18, the backlight device may be configured as shown in FIG. 19, and the backlight device illustrated in FIG. 19 includes the light guide plate 10. And a light supply unit group including a light source 24, a storage container 290, a light sheet 400, a transparent diffusion acrylic plate 600 in which a diffusion plate / diffusion sheet is combined, and a display unit fixing cover 500. do.

That is, a transparent optical acrylic plate 600 having a diffusion plate or a diffusion sheet is further provided between the light guide plate 10 and the light sheet 400 of the backlight device illustrated in FIG. 18.

In the backlight device shown in FIG. 19, the transparent optical acrylic plate or the diffuser plate combined with the diffuser sheet is positioned at a position of about 1 to 3 mm or appropriately spaced apart from the light guide plate 10 so as to remove bright and dark lines. In addition, the heat generated from the light source of the light emitting diode module or the lamp is not transmitted to the liquid crystal to improve the heat dissipation effect.

In the liquid crystal display device to which the present invention is applied as described above, since the corner portion where the light source is located may be bright, the brightness of the screen may be made uniform by changing the diffusion pattern formed at the corner portion of the light guide plate 10.

The light supply unit 20 is composed of a PCB substrate 22 and a light source 24 attached to and fixed to the PCB substrate 22 as shown in FIGS. 2 to 4. In this case, the light source 24 is a light emitting diode module having a tricolor light emitting diode, and a plurality of light emitting diode modules are arranged on a single PCB substrate 22 at regular intervals, and the PCB substrate 22 is a light guide plate 10. The light source 24 is fixed to a separate storage container 290 so that the light source 24 can be maintained at a predetermined distance. At this time, the method of fixing the PCB substrate 22 to the storage container 290 is to be fixed by fastening using a fastening member such as a screw (Screw) as shown in the accompanying drawings, or not shown in the drawing, but the PCB By forming a slot or guide shape to which the substrate 22 can be inserted, the PCB 22 is inserted into and fixed to the slot or guide shape.

Meanwhile, the light source 24 may be formed of a lamp as shown in FIGS. 9 to 12 instead of the light emitting diode module. When the light source is implemented as a lamp as described above, as shown in FIG. 9, the lamp is positioned at the bent portion 12 of the light guide plate 10, and then the lamp case 25 is bonded to the light guide plate 10. By combining them, the lamp can be protected from the external environment. In this case, the shape of the lamp is a straight line as shown in FIG. 10 or an “a” shape as shown in FIG. 11, but the shape of the lamp may be formed in various shapes other than the straight or storage shape. Can be.

5 and 8 are still other embodiments of FIG. 2, wherein the backlight device illustrated in FIG. 5 is different from the position of the light source 24 provided in the backlight device illustrated in FIG. 2. 290. In the case where it is provided inside, in this case as well, light is incident in the horizontal direction as in FIG.

In the backlight device of FIG. 8, the light guide plate 10 is provided with a groove, and then a light source is inserted into the groove to allow light to enter the light guide plate 10. In this case, only a light source or a lamp provided on the inner surface of the storage container 290 of FIG. 5 may be used as the light source of the backlight device of FIG. 8.

In addition, the light guide plate 10 has a plurality of grooves formed on the upper surface thereof in parallel to each other in the longitudinal direction 17 as shown in the accompanying drawings, and a plurality of other grooves are formed on the plurality of grooves formed in the longitudinal direction. It is formed in the transverse direction 16 in parallel to each other, the groove has an inclined surface that gradually decreases inward.

Meanwhile, the light guide plate 10 has a different embodiment from the light guide plate 10 of FIG. 13 as shown in FIG. 14, and another embodiment of the light guide plate 10 has a plurality of grooves on a lower surface thereof. 18 are formed parallel to each other in the longitudinal direction, and the plurality of grooves 18 have inclined surfaces having a lower depth toward the center.

In addition, the light guide plate 10 of FIG. 14 may be modified as shown in FIG. 15, and the modified light guide plate 10 will be described. First, a plurality of grooves 18a are parallel to each other in the longitudinal direction on both bottom surfaces. The plurality of grooves 18a have an inclined surface that gradually decreases inwardly, and the plurality of grooves 18b are formed in parallel to each other in the longitudinal direction on the lower surface of the central portion, and the plurality of grooves 18 18b) has an inclined surface that gradually decreases in depth, and the plurality of grooves 18a formed on the lower surfaces of both ends are formed in parallel with the plurality of grooves 18b formed on the lower surface of the central portion.

And another embodiment of the light guide plate 10 will be described with reference to the accompanying drawings 16 and 17, the groove 19 is formed on the inner surface so that the thickness thereof is constant along the shape of the lower surface.

The longitudinal length L1 of the grooves 17a, 17b, 18a, and 18b and the gap L2 between the grooves and the grooves are preferably 1 to 6 mm.

In addition, the thickness L3 of the light guide plate 10 is preferably formed to be 1mm to 6mm, 3mm is most suitable.

As described above, if the longitudinal length L1 and the gap L2 of the groove are limited to 2 mm and the thickness L3 to 3 mm, the gap between the molds is kept constant regardless of the volume during injection molding. Not only the time required for molding is shortened, but precise injection molding can be achieved without shrinkage.

FIG. 18 is an exploded perspective view of a liquid crystal display according to the present invention. As in the conventional case, the display unit 100 again includes a liquid crystal display panel 1, a tape carrier package 2, and a driving signal generator (not shown). It consists of a printed circuit board (3) comprising a).

The present invention is not limited to the above embodiments, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention included in the appended claims.

According to the present invention having the above-described configuration, operation and preferred embodiment, a plurality of light sources are stacked and arranged on a stepped light guide plate used in a large screen liquid crystal display, and a light supply unit is provided on one side of the light guide plate. There is an effect to have a uniform brightness while greatly improving the brightness.

Claims (10)

In the backlight device of the liquid crystal display device, The backlight device, A light guide plate 10 having a plurality of bent portions 12 formed at both end portions or four-side end portions in a square shape and symmetrical with both sides from a center; A light supply unit 20 provided at the bent portion 12 of the multi-stage so that light is incident on the light guide plate 10 horizontally; And It includes a reflecting plate 30 provided on the upper receiving container for receiving the light guide plate 10, The light supply unit 20 is made of a light source 24 attached to and fixed to the PCB substrate 22 and the PCB substrate 22, one of the LED module or the lamp is selected, The light guide plate 10 has fixing protrusions C formed at each corner of an upper surface thereof, and coupling holes H coupled to the fixing protrusions C are formed in the backlight device of the liquid crystal display device. The fixing sheet (C) is coupled to the H) is further coupled to the light guide plate 10, the optical sheet 400 is fixed, The groove of the liquid crystal display device, characterized in that grooves are formed at both ends of the lower side of the light guide plate (10) symmetrically from the center at regular intervals, and light sources are inserted into and fixed to the inside of the groove. delete delete delete delete The method of claim 1, wherein the light guide plate 10, A plurality of grooves 17 are formed parallel to each other in the longitudinal direction on the upper surface, a plurality of further grooves are formed in the transverse direction 16 parallel to each other in the plurality of grooves formed in the longitudinal direction, the grooves A backlight device of a liquid crystal display device, characterized by having an inclined surface that gradually decreases inwardly. The method of claim 1, wherein the light guide plate 10, A plurality of grooves 18a are formed parallel to each other in the longitudinal direction on both side lower surfaces, and the plurality of grooves 18a are characterized in that they have an inclined surface that gradually decreases inwardly, A plurality of grooves 18b are formed parallel to each other in the longitudinal direction on the lower surface of the central portion, and the plurality of grooves 18b are characterized in that they have an inclined surface that gradually decreases in depth to the center. The plurality of grooves (18a) formed in the lower surface of the both ends is formed in parallel with the plurality of grooves (18b) formed in the lower surface of the central portion of the backlight device of the liquid crystal display device. The method of claim 1, wherein the light guide plate 10, The backlight device of the liquid crystal display device, characterized in that the groove (19) is formed on the inner surface so that the thickness thereof is constant along the shape of the lower surface. The longitudinal length L1 of the groove and the gap L2 between the groove and the groove, The backlight device of the liquid crystal display device, characterized in that formed in 1 to 6mm. The thickness L3 of the light guide plate according to claim 6 or 7, The backlight device of the liquid crystal display device, characterized in that formed in 1mm to 6mm.

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