KR102131339B1 - Backlight unit for desplay device - Google Patents

Abstract

The present invention relates to a backlight unit for a display device, in particular, provided in a rectangular frame shape, each having an assembly position setting unit provided at both inner corners at one end of the longitudinal direction, and at each outer edge end of both sides of the other longitudinal direction. A backlight housing provided with an assembly fixing part, a diffusion sheet and a prism sheet stacked on a front end of the backlight housing, a reflective sheet and a backlight housing cover stacked on a rear end of the backlight housing, and a longitudinal end of the backlight housing After being temporarily fixed to be positioned at the assembly position setting unit, the other end in the longitudinal direction is fitted and moved to the assembly fixing part, and thus includes a light guide plate that is fixed, thereby providing an advantage of preventing product degradation.

Description

Backlight unit for display devices{BACKLIGHT UNIT FOR DESPLAY DEVICE}

The present invention relates to a backlight unit for a display device, and more particularly, to a backlight unit for a display device capable of preventing the light guide plate from being damaged by vibration and shock by fixing the light guide plate assembly portion more safely and firmly. .

A liquid crystal display device (Liquid Crystal Display Device, hereinafter referred to as'LCD'), which is a flat panel display device, does not emit light in itself, unlike other display devices, and thus requires a separate external light source to realize an image. . Therefore, the LCD further includes a backlight device as an external light source in addition to the liquid crystal panel, and the backlight device realizes high-quality images by uniformly supplying high-brightness light to the liquid crystal panel.

Such a backlight device refers to a surface light source unit installed on a rear surface of a liquid crystal panel to realize an image of a display device such as an LCD, and a light emitting diode (hereinafter referred to as'LED') as a light source of the backlight device. Is mainly used. The backlight device is divided into a direct lighting type or an edge lighting type backlight device according to the position in which the LED light source is disposed, and the direct type backlight device is provided with a point light source under the diffusion plate and through the diffusion plate. It is a method of directly illuminating light on a liquid crystal panel, and a side type backlight device is a method in which a point light source is disposed on the side of the light guide plate to indirectly illuminate light through the light guide plate and the optical sheet. Recently, a side type backlight device that is advantageous for slimming and exhibits uniform light characteristics is mainly used as a surface light source for LCDs.

The conventional backlight unit for a display device is coupled by a so-called non-flow fastening method in which a predetermined assembly tolerance is provided between the backlight housing and the light guide plate when coupling the light guide plate using a coupling mechanism for coupling the light guide plate to the backlight housing. . This is because the assembly itself is not possible without an assembly tolerance between the backlight housing and the light guide plate.

By the way, as described above, if a predetermined assembly tolerance is given, the assembled light guide plate may cause the phenomenon of the separation of the optical components, the diffusion sheet, the prism sheet, and the reflection sheet, which are neighboring components, by vibration or impact later, as well as the light guide plate and There is a possibility that the light guide plate coupling mechanism may be deteriorated due to the cracking and cracking phenomenon, and problems such as the observation of parts observed by the naked eye due to the inflow of the cracked and broken foreign matter to the LCD side may cause quality deterioration.

The present invention has been devised to solve the above technical problem, and it is possible to easily fix the light guide plate in a flow fixing method by moving away from the conventional non-flow fixing method, as well as optical sheets, which are a chronic problem of the non-flow fixing method. An object of the present invention is to provide a backlight unit for a display device capable of preventing the cracking and cracking of the light guide plate and the surrounding components.

One embodiment of the backlight unit for a display device according to the present invention is provided in a rectangular frame shape, and assembly position setting units are provided at both inner corners of one end portion in the longitudinal direction, and at both outer edge ends of the other end portion in the longitudinal direction. Each of the backlight housing having an assembly fixing part, a diffusion sheet and a prism sheet disposed on the front end of the backlight housing, a reflective sheet and a backlight housing cover disposed on the rear end of the backlight housing, and a longitudinal end of the backlight housing After being temporarily fixed to be positioned in the assembly position setting portion, the other end in the longitudinal direction may include a light guide plate that is fixed after being moved to the side of the assembly fixing portion.

Here, the assembly position setting unit formed in the backlight housing may be provided in a shape in which the light guide plate is assembled at a predetermined position by an assembly position rib provided at one end in the longitudinal direction of the light guide plate.

In addition, the assembly position setting unit formed in the backlight housing may be provided as an assembly position rib protruding from one side of both inner corner portions of one end portion in the longitudinal direction of the backlight housing and contacting one end in the longitudinal direction of the light guide plate.

In addition, the assembly fixing portion formed in the backlight housing may be provided with a screw fastening hole formed so that the countersunk head screw penetrates from the outside of the backlight housing to the inside.

In addition, an assembly guider may be provided at an outer edge of the other end portion in the longitudinal direction of the light guide plate to form a screw fixing hole through which the countersunk head screw that passes through the screw fastening hole is fastened.

In addition, in each corner portion of the reflective sheet, incisions cut in a chamfering manner may be respectively formed.

In addition, a plurality of fixing holes opened in the front-rear direction may be formed in the backlight housing cover to correspond to positions of the assembly position setting unit and the assembly fixing unit.

In addition, the screw fixing hole formed in the assembly guider may be provided with an inclined portion capable of slipping the assembly guider and the light guide plate in one direction in the longitudinal direction by the plate head screw when the plate head screw is fastened.

Further, the screw fastening hole may be formed in a slot shape elongated in the longitudinal direction of the backlight housing by a slip movement distance of the assembly guider.

According to an embodiment of the backlight unit for a display device according to the present invention, it is possible to achieve various effects as follows.

First, in the installation of the light guide plate, since it can be installed with a certain margin of tolerance on the left and right in the longitudinal direction, it has an effect of improving the assembly.

Second, since the light guide plate is securely fixed so as not to flow inside the backlight housing through the assembly fixing part, the product quality is prevented from being prevented by preventing the light guide plate from being cracked or cracked or the composition and the crack around the light guide plate are prevented. It has the effect.

1 is an exploded perspective view showing an embodiment of a backlight unit for a display device according to the present invention,
2 is a front view showing an embodiment of a backlight unit for a display device according to the present invention,
3 is a cross-sectional view taken along line AA of FIG. 2 and a partially enlarged view,
4 is a cross-sectional view taken along the line BB of FIG. 2 and a partially enlarged view,
5 is a partial cross-sectional view showing a modification of the fixing guide in the configuration of FIG. 1.

Hereinafter, an embodiment of the backlight unit for a display device according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing the embodiments of the present invention, when it is determined that detailed descriptions of related well-known configurations or functions interfere with the understanding of the embodiments of the present invention, detailed descriptions thereof will be omitted.

In describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. Also, unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

1 is an exploded perspective view showing an embodiment of a backlight unit for a display device according to the present invention, FIG. 2 is a front view showing an embodiment of a backlight unit for a display device according to the present invention, and FIG. 3 is AA of FIG. 2 It is a cross-sectional view taken along the line and a partially enlarged view, and FIG. 4 is a cross-sectional view taken along the line BB of FIG. 2 and partially enlarged.

One embodiment of a backlight unit for a display device according to the present invention, as shown in FIGS. 1 to 4, the backlight housing 10, the light guide plate 20, and the light guide plate installed inside the backlight housing 10 ( The diffuser sheet 30, the prism sheet 40, the LCD 60 and the window 70, which are stacked on the front end of the backlight housing 10 based on 20), and the backlight housing based on the light guide plate 20 ( 10) may include a reflective sheet 90 and a backlight housing cover 100 that are stacked on the rear end.

The backlight housing 10 may be formed in a rectangular frame shape, as shown in FIG. 1. Here, the rectangle means a rectangle having a shape having a different length of adjacent sides adjacent to one side, and is adopted as one of a larger horizontal length or a larger vertical length depending on the type of product applied. Can be. The frame shape is not limited to a rectangle, and may be square.

For convenience, the lower left portion of FIG. 1 will be referred to as a front portion, and the upper right portion of FIG. 1 will be referred to as a rear portion.

The backlight housing 10 may be formed by combining four thin plates having a thickness of approximately a predetermined length before and after (recently, the thickness is gradually decreasing because a slim or ultra-slim product can be manufactured). Various components as described above may be installed inside the backlight housing 10.

The backlight housing 10 may be provided with assembly position setting portions at both inner corner portions of one end portion in the longitudinal direction, and assembly fixing portions may be provided at both edge ends of the other end portion in the longitudinal direction. The assembly position setting unit and the assembly fixing unit will be described in more detail later.

The diffusion sheet 30 and the prism sheet 40 may be coupled to the backlight housing 10 after being stacked and installed by the sheet frame 50, as shown in FIG. 1. The diffusion sheet 30 and the prism sheet collect and diffuse light emitted from the light guide plate 20 to improve luminance and uniformity of luminance of the backlight device. The diffusion sheet 30 and the prism sheet 40 may be composed of a plurality of light control sheets.

The reflective sheet 90 may be stacked to contact the back surface of the light guide plate 20. The reflective sheet 90 may be installed in the backlight housing 10 together with the light guide plate 20. The reflective sheet 90 reflects light emitted from the rear surface of the light guide plate 20 into the light guide plate 20 to improve the brightness of the backlight device. The reflective sheet 90 may be made of a metal sheet having excellent light reflectivity or a sheet coated with a light reflecting material such as silver (Ag) on the surface.

The light guide plate 20 may convert light from a plurality of point light sources incident from the light source module to a surface light source through total internal reflection, thereby providing it as a liquid crystal panel. The light guide plate 20 is a kind of light conversion element. The light guide plate 20 may be made of a transparent acrylic-based resin having a predetermined refractive index. As an example, the light guide plate 20 may be made of a resin such as PMMA (Polymethylethacrylate), PS (Poly styrene), MS (Meta styrene) or PC (Polycarbonate).

In addition, among the inner surface of the backlight housing 10 and each outer surface of the light guide plate 20, the backlights 81 and 82 for daylight are provided, and the inner surface and the light guide plate 20 of the backlight housing 10 are provided. Night backlights 83 and 84 may be provided on the left and right of each of the outer surfaces. However, the present invention is not limited thereto, and only a portion of the backlights 81 to 84 for day and night may be provided. In addition, it is not limited to the name, and the lighting for the day and night backlights 81 to 84 can be operated in various combinations. For example, when it is dark, only the backlight for night (83,84) is lit, when it is bright, only the backlight for day (81,82) is lit, and when it is very bright, both the day and night backlights (81~84) are controlled to be lit. It can be, and is not limited to, it can be variously controlled.

The daytime backlights 81 and 82 and the nighttime backlights 83 and 84 are a kind of light source module, and are light emitting sources of a backlight device that provides light inside the light guide plate 20. The light source module may be configured as an LED array in which a plurality of LEDs are mounted on a substrate. The light source module may be disposed on both sides opposite to each other on the inner surface of the backlight housing 10 so that the light output surface of the LED faces the light input surface of the light guide plate 20.

In an embodiment of the present invention, daylight backlights 81 and 82 are installed on the inner top and bottom of the backlight housing 10 to face each other, and night backlights 83 and 84 on the inner left and right sides of the backlight housing 10, respectively. A structure in which is installed opposite to each other was adopted.

The assembly process of the backlight unit for a display device according to the present invention having such a configuration will be described with reference to FIGS. 3 and 4 as follows.

3 and 4, the diffusion frame 30 and the prism sheet 40 are laminated on the front end of the backlight housing 10 to combine the seat frame 50. At the front end portion of the backlight housing 10, a frame fastening portion for coupling the seat frame 50 may be separately formed.

Next, the LCD 60 and the window are fastened in front of the diffusion sheet 30 and the prism sheet 40 to complete the assembly of the front portion of the backlight unit for a display device according to the present invention.

Then, the light guide plate 20 is installed inside the backlight housing 10. In more detail, one end of the light guide plate 20 in the longitudinal direction is fitted to an assembly position setting unit provided at inner corners of both sides (ie, the upper and lower sides of the drawing) of the longitudinal end of the backlight housing 10. That is, the backlight unit for a display device according to the present invention is not a non-flow fixing method that precisely fits and engages both the left and right ends of the backlight housing 10, and the light guide plate 20 is coupled to the assembly position setting unit at one end of the length. After that, the position of the light guide plate 20 is changed, and then a flow fixing method is used to fix the flow so that no further flow occurs through the assembly fixing part.

Here, the assembly position setting unit formed inside the backlight housing 10 may be provided in a shape in which the light guide plate 20 is assembled at a predetermined position by an assembly position rib 21 provided on the outer side in the longitudinal direction of the light guide plate 20. have. However, the assembly position rib is not necessarily provided on the outer side in the longitudinal direction of the light guide plate 20, and as shown in FIG. 3, the assembly position rib 11 in the longitudinal direction of the light guide plate 20 inside the backlight housing 10 ) May be provided to protrude and contact one end in the longitudinal direction of the light guide plate 20.

On the other hand, the other end of the light guide plate 20 in the state where one end in the longitudinal direction is temporarily assembled by the assembly position setting unit inside the backlight housing 10 is finally fixed by the assembly fixing unit. Here, the assembly fixing parts provided at the corner ends of both sides (ie, upper and lower sides in the drawing) of the other end portion in the longitudinal direction of the backlight housing 10 are provided with countersunk head screws 25 from outside of the backlight housing 10 to the inside. It may be provided with a screw fastening hole 13 formed to penetrate.

In addition, an assembly guider 23 is formed at the outer edge of the other end portion of the light guide plate 20 in the longitudinal direction, in which the screw fixing hole 24 through which the countersunk head screw 25 is fastened through the screw fastening hole 13 is fastened. Can.

Here, the screw fastening hole 13 provided as an assembly fixing part on the outside of the backlight housing 10 is exactly the screw fixing hole 24 of the assembly guider provided at the outer edge of the other end portion in the longitudinal direction of the light guide plate 20. It is preferably designed to be provided at a matching location.

Accordingly, the assembler fits the longitudinal end of the light guide plate 20 into contact with the assembly position setting unit with a predetermined clearance tolerance at the left and right ends of the light guide plate 20 installed inside the backlight housing 10. After pre-assembly, the screw fastening plate 13, which is an assembly fixing part, and the screw fixing hole 24 of the assembly guider provided in the light guide plate 20 coincide with each other by moving the light guide plate 20 to a location where the assembly position setting unit is located. The light guide plate 20 can be firmly fixed through the plate head screw 25. Here, the reflective sheet 90 may be pre-laminated on the rear surface of the light guide plate 20, and it is natural that the reflective sheet 90 can be stacked on the rear surface of the light guide plate 20 after the light guide plate 20 is installed. will be.

In addition, after assembling the light guide plate 20 in the backlight housing 10, the assembly of the front portion of the backlight unit for a display device according to the present invention can be completed by combining the backlight housing cover 100 with the backlight housing 10. . The installation order of each component for the backlight housing 10 may be different according to embodiments, but after assembling the light guide plate 20 in the interior of the backlight housing 10, the light guide plate 20 is centered. It is also possible to take the order of assembling each component in front and rear of the backlight.

On the other hand, in each corner portion of the reflective sheet 90, which is stacked and disposed on the rear surface of the light guide plate 20, cutouts 91 cut in a chamfering manner may be respectively formed. The cutout portion 91 formed on the reflective sheet 90 is previously assembled when the reflective sheet 90 is laminated and assembled on the back surface of the light guide plate 20 in advance, when the light guide plate 20 is installed inside the backlight housing 10, as described above. It may be configured to prevent interference with the assembly position setting unit and the assembly fixing unit. However, it is preferable that the incision 91 is formed in a size in a range that does not affect the reflection efficiency of the reflective sheet 90 as a whole.

In addition, a plurality of fixing holes 101 opened in the front-rear direction may be formed in the backlight housing cover 100 to correspond to positions of the assembly position setting unit and the assembly fixing unit. The assembler can visually check the assembly state of the light guide plate 20 through a plurality of fixing holes 101 from the outside of the backlight housing cover 100 or re-adjust using a separate tool.

5 is a partial cross-sectional view showing a modification of the assembly guider 23 in the configuration of FIG. 1.

After the light guide plate 20 is installed inside the backlight housing 10, the light guide plate 20 should be prevented from flowing due to vibration or shock transmitted from the outside. This is because if the light guide plate 20 flows after installation, it may cause a cracking and cracking phenomenon of the light guide plate 20 as well as a cracking and cracking phenomenon of the optical sheet installed around the light guide plate 20.

In the case of one embodiment of the backlight unit for a display device according to the present invention, the conventional non-flow fixing method is avoided in order to prevent the above-described problem in advance, and the first end of the light guide plate 20 in the assembly position setting unit is firstly moved. The main purpose is to install the light guide plate 20 firmly by the assembly fixing part after fitting.

However, even according to the above-described embodiment, fixing the other end portion in the longitudinal direction of the light guide plate 20 in place by the assembly fixing part may be a very difficult assembly process. A modification of the fixing guide 23 referred to in FIG. 5 makes it possible to solve the difficulty of assembly.

In more detail, the screw fixing hole 24 formed in the assembly guider 23 is assembled by the plate head screw 25 when the plate head screw 25 is fastened, as shown in FIG. 5. ) And the light guide plate 20 may be provided with an inclined portion 24 ′ capable of slip-moving in one direction in the longitudinal direction.

In addition, the screw fastening hole 13 may be formed in a slot shape long in the longitudinal direction of the backlight housing 10 by the slip movement distance of the assembly guider.

Therefore, as shown in Figure 5, the assembler, as possible, during the process of fixing the plate head screw 25 to the screw fixing hole 24 through the inclined portion 24' and the screw fastening hole 13 formed obliquely as possible. Since the 20 can be further moved to the other side in the longitudinal direction, the light guide plate 20 can be fixed more firmly inside the backlight housing 10.

In the above, one embodiment of the backlight unit for a display device according to the present invention has been described in detail with reference to the accompanying drawings. However, the embodiments of the present invention are not necessarily limited to the above-described embodiments, and it is natural that various modifications and equivalent implementations by a person skilled in the art to which the present invention pertains are possible. will be. Therefore, the true scope of the present invention will be defined by the claims below.

10: backlight housing 11: assembly position rib
13: screw fastening hole 20: light guide plate
21: Assembly position rib 23: Guide
24: screw fixing hole 25: countersunk head screw
30: diffusion sheet 40: prism sheet
50: seat frame 60: LCD
70: Windows 81, 82: daytime backlight
83,84: Night backlight 90: Reflective sheet
91: incision 100: backlight housing cover
101: fixing hole

Claims (7)

A backlight housing provided in a rectangular frame shape, each having an assembly position setting portion at both inner corners of one end portion in the longitudinal direction, and an assembly fixing portion at both outer edge ends of the other end portion in the longitudinal direction;
A diffusion sheet and a prism sheet disposed in front of the backlight housing;
A reflective sheet and a backlight housing cover which are stacked on the rear end of the backlight housing;
A light guide plate having one end in the longitudinal direction temporarily fixed to be positioned in the assembly position setting portion of the backlight housing, and fixed after being fixed to the other end of the assembly and moved to the assembly fixing portion;
Daytime backlights which are installed to face each other on the inside and the bottom of the backlight housing; And
Includes a backlight for night, which are respectively installed opposite to each other on the inner left and right sides of the backlight housing.
The reflective sheet is disposed on the back surface of the light guide plate, and incision portions are formed in a chamfering manner at each corner,
The assembly fixing portion formed in the backlight housing is provided with a screw fastening hole formed so that the countersunk head screw is penetrated from the outside of the backlight housing to the inside,
On the outer edge of the other end portion in the longitudinal direction of the light guide plate, an assembly guider having a screw fixing hole through which the plate head screw is fastened through the screw fastening hole is formed is provided,
The screw fixing hole formed in the assembly guider is provided with an inclined portion capable of slipping the assembly guider and the light guide plate in one direction in the longitudinal direction by the plate head screw when the plate head screw is fastened,
The screw fastening hole, the backlight unit for a display device, formed in a slot shape elongated in the longitudinal direction of the backlight housing by the slip movement distance of the assembly guider. According to claim 1,
The assembly position setting unit formed in the backlight housing is provided in a shape in which the light guide plate is assembled at a predetermined position by an assembly position rib provided on one side in the longitudinal direction of the light guide plate, a backlight unit for a display device. According to claim 1,
The assembly position setting unit formed on the backlight housing is provided with an assembly position rib that protrudes from one side of both inner corners of one end portion of the longitudinal direction of the backlight housing and contacts one end of the light guide plate in the longitudinal direction. delete According to claim 1,
A backlight unit for a display device having a plurality of fixing holes opened in a front-rear direction corresponding to positions of the assembly position setting unit and the assembly fixing unit is formed on the backlight housing cover. delete delete

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