KR100956422B1 - Backlight unit of liquid crystal display device - Google Patents

Abstract

The present invention relates to a backlight unit of a liquid crystal display device capable of reducing weight and cost by reducing the number of parts by integrating a component such as a bottom chassis and a cover into a single unit.

The present invention implements a new type of backlight assembly using a composite mold in the form of a plastic injection molding that can perform various functions such as fixing a lamp, supporting a light guide plate, and reflecting sheet, thereby dramatically reducing the number of parts. Provided is a backlight unit of a liquid crystal display device which can be expected to reduce cost and light weight.

LCD, backlight unit, complex mold, light weight

Description

Backlight unit of liquid crystal display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit of a liquid crystal display device. More particularly, the present invention relates to a liquid crystal display device that can reduce the number of parts and reduce the cost by integrating a bottom chassis, a cover, and the like into a single unit. It relates to a backlight unit.

As the information and communication industry is rapidly developed, the use of display devices is rapidly increasing, and in recent years, display devices capable of satisfying the conditions of low power, light weight, thin film, and high resolution are required.

In response to these demands, display devices using liquid crystal displays or organic light emitting characteristics have been developed.

Thin Film Transistor-Liquid Crystal Display (TFT-LCD), which has excellent color reproducibility, low power consumption, and is made thin, is one of the most widely used flat panel display devices. The LCD includes a liquid crystal display panel into which liquid crystal is injected, a backlight unit which is positioned under the liquid crystal display panel, and a driving unit for driving the liquid crystal display panel.

The backlight unit may include a light guide emitting light, a light guide plate provided to the liquid crystal display panel by changing the distribution of light provided from the light source, an optical sheet and a light guide plate to improve the uniform incidence of luminance distribution of the light provided from the light guide plate. It consists of an optical sheet etc. which make the light emitted to the back incident to a light guide plate.

The light source includes an LED, a lamp, and the like, and the optical sheet includes a diffusion sheet for diffusing light incident from the light guide plate toward the liquid crystal display panel, and a prism sheet for condensing the diffused light to improve vertical incidence. .

1 to 3, the backlight unit includes a bottom chassis 11 for installing the lamp 10 and a reflective sheet attached to an inner surface of the bottom chassis 11. 12) and a plurality of support pins 13 for fixing the lamp, both side molds 14 for preventing light from leaking to the side, and the light guide plate 15 for finishing the upper part of the bottom chassis 11; The cover 16 is mounted to the edge of the bottom chassis 11 to cover the light guide plate 15.

Thus, the backlight unit is composed of components that enable the liquid crystal panel to display constant information by irradiating light on the liquid crystal panel, and each component plays a role of increasing brightness and widening the viewing angle.

However, the conventional backlight unit has a disadvantage in that the number of components, the manufacturing ability is low and the manufacturing cost increases, there is a disadvantage in terms of weight.

For example, it is composed of a large number of parts such as a bottom chassis manufactured by press working, a side mold manufactured in the form of plastic injection molding, a support pin, a cover, and a reflective sheet, and then produced each in a separate process. Since each part has to be assembled one by one, not only the production is inferior, but also the assembly work is difficult and time-consuming.

In other words, the process of attaching the reflective sheet to the inner surface of the bottom chassis, attaching the support pin, inserting the side mold after installing the lamp, and attaching the cover after installing the light guide plate are difficult and time-consuming. There are disadvantages.

In addition, the bottom chassis is made of a metal material, and since many parts are assembled here, it is very disadvantageous in terms of weight.

As such, the conventional backlight unit is disadvantageous in terms of manufacturability and assemblability due to the large number of parts, and in terms of weight, and thus incurs an increase in cost and thus has a disadvantage in economic efficiency.

Therefore, the present invention has been made in view of the above, by implementing a new type of backlight assembly using a composite mold in the form of plastic injection molding that can perform a variety of functions such as lamp fixing, light guide plate support, reflecting sheet role In addition, the object of the present invention is to provide a backlight unit of a liquid crystal display device that can dramatically reduce the number of parts, and thus, can reduce costs and reduce weight.

In order to achieve the above object, the backlight unit provided in one embodiment of the present invention includes a lamp and a light guide plate, an inner surface of which is a reflective surface, and a plurality of supporter pins for fixing the lamp are integrally formed on the bottom of the inner surface thereof. And a plurality of clamping members fastened to the side of the composite mold while pressing the edge portion of the light guide plate to fix the light guide plate disposed on the front surface of the composite mold and covering the lamp. It is characterized by including.

Here, the light guide plate seating surface for seating the light guide plate is formed at the edges of the front four sides of the composite mold, wherein at least two of the light guide plate seating surface is formed with a protruding band for blocking the light guide plate from the outside. It is preferable to form a plurality of positioning protrusions for holding the position of the light guide plate while being fitted in the shape of the light guide plate and unevenness.

In the backlight unit provided in the present invention, since the parts for assembling the lamp and the light guide plate are composed of only one composite mold and four clamping members, the number of parts can be drastically reduced. There is an effect that can increase the competitiveness of the product, such as saving and weight can be realized.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

4 to 6 are perspective views illustrating a backlight unit of a liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIGS. 4 to 6, the backlight unit includes a composite mold 18 formed in a single unit form of one plastic injection molded product, and the lamp 10 is installed inside the composite mold 18. At the same time, the front surface is made of a structure in which the light guide plate 15 is installed.

In other words, the backlight unit provided in the present invention serves as the above components instead of the assembly structure of components such as a bottom chassis, a reflective sheet, a support pin, a side mold, and a cover. By employing the composite mold 18 in one single piece form that can be performed, the greatest feature is that the number of components is drastically reduced.

To this end, the composite mold 18 is made of a front open type rectangular box type having a rectangular bottom plate 18a and a wall 18b formed along four sides of the bottom plate 18a.

Of course, in this case, the composite mold 18 is provided with a PCB assembly (not shown) for backlight control and an opening (not shown) for drawing out the lamp power line at each end of the bottom plate and the bottom plate.

The composite mold 18 may have an appropriate structural rigidity in terms of its structure, that is, the cross-sectional structure of the wall 18b has a trapezoidal cross-sectional structure, so that the composite mold 18 may be concerned about the weakness of strength due to a single piece of plastic material. I can eliminate it neatly.

The inner bottom surface of the composite mold 18, that is, the front surface of the bottom plate 18a, can serve as a reflecting surface 17. At this time, the reflecting surface 17 uses its own surface of the mold material. It may be a composition, or may be formed using a surface coated with a separate reflective material on the bottom surface.

For example, if a mold is made using a material such as PC, PC + GF, etc., a surface having excellent reflection characteristics can be obtained, and thus it can be used as a reflective surface, or a material such as UN blocker or paint is coated on the bottom surface. Can be used as a reflecting surface.

On the bottom plate 18a of the composite mold 18, a plurality of support pins 13 for supporting approximately six lamps 10 are formed at appropriate positions, and at this time, the support pins 13 have lamps. The lamp 10 can be fixed by inserting and hanging the 10.

Here, the support pin 13 may be integrally molded when the composite mold is injected.

In order to more stably support the lamp 10, the inner surface of both walls 18b of the composite mold 18, for example, both walls 18b arranged in the longitudinal direction (X-axis direction), is in the width direction (Y-axis direction). Protruding pillars 20 are formed integrally with each other while being arranged at regular intervals to form a space to accommodate the end of the lamp 10 therebetween.

At this time, the protruding pillar 20 is formed to protrude inwardly, and each of the lamps are arranged side by side along the width direction, the end of the lamp 10 is located in the space between the adjacent protruding pillar 20 The alignment of the 10 can be kept stable.

In particular, since the bundle portion of one end of the lamp 10 to which the wires or the like are connected is fitted between the protruding pillars 20, the supporting state of the lamp 10 may be more firm.

The composite mold 18 includes a means for stably supporting the light guide plate 15 installed while closing the front surface of the composite mold 18.

To this end, the light guide plate seating surface 21 is formed at the edges of the front four sides of the composite mold 18, that is, the front surface of the wall 18b, and the entire circumference of the edge of the light guide plate 15 is formed on the light guide plate seating surface 21 thus formed. The light guide plate 15 may be installed in a supported form.

In particular, at least two of the light guide plate seat surfaces 21 on the four sides of the mold, for example, two upper and lower light guide plate seat surfaces disposed in the width direction, are provided with protrusion bands 22, so that the ends of the light guide plate 15 are formed. Can be prevented from the outside.

In addition, the light guide plate 15 may be disposed on at least two light guide plate seat surfaces 21 except for the light guide plate seat surface 21 having the protruding band 22, in order to accurately hold the installation position of the light guide plate 15. A plurality of positioning protrusions 23 are formed to hold the position of the light guide plate 15 while being fitted in the) side and the concave-convex shape.

For example, the positioning protrusions 23 are formed to protrude in a substantially " T " shape while being assigned to the upper surface of each protruding pillar 20 one by one, and the positioning protrusions 23 are also arranged at the edge of the light guide plate 15. The T-shaped groove portion 26 corresponding to the one-to-one correspondence is formed so that the protrusion and the groove portion are fitted to each other when the light guide plate is installed, so that the light guide plate 15 can be installed at the correct position, and the flow can be maintained even after the installation. You can prevent it.

A clamping member 19 is provided for final fixing of the light guide plate 15.

The clamping member 19 is a means for pressing and fixing the light guide plate 15. In the present invention, four clamping members 19 are applied to fix four corner portions of the light guide plate 15.

The clamping member 19 is a hole (25a) formed in the wall (19b) of the composite mold (18) by using a clip 24 and a guide pin 25 on both sides extending from the back of the body ( It is mounted to the structure fastened to 25b).

In this case, the hole into which the clip is fitted has a structure that also passes through the side, so when the disassembly is necessary, the clip fastening state can be easily released by using a tool such as a driver.

Therefore, the assembly process of the backlight unit configured as described above is as follows.

First, the number of parts to be assembled is a total of four, such as one composite mold, a lamp assembly, a light guide plate of four sheet combinations, and four clamping members.

The composite mold 18 may be manufactured by a known injection molding method, wherein the support pin 13, the protruding pillar 20, the light guide plate seat 21, the protruding band 22, and the positioning protrusion 23 are provided. A plurality of holes and the like are integrally molded together.

By using the support pin 13 in the bottom plate 18a of the composite mold 18, about six lamps 10 are aligned and assembled.

At this time, each of the lamps 10 are fixed in the middle of the length by the support pin 13, and both ends are positioned or fitted in the space between the projection pillar 20 can be firmly fixed, the lamp 10 The electric wires and the like can be taken out to the back of the mold through one side opening of the bottom plate 18a.

After the lamp 10 is assembled, the light guide plate 15 is assembled.

That is, the edge portion of the light guide plate 15 is brought into close contact with the light guide plate seat surface 21 provided at the edge of the composite mold 18, and then the clamping member 19 is fastened to the composite mold 18 from each corner of the light guide plate. The lower surface of the light guide plate 15 may be assembled to the front surface of the composite mold 18 while the edge portion thereof is fitted between the rear surface of the clamping member 19 and the seat surface.

Here, the light guide plate may include a diffusion sheet, a prism sheet, a protective sheet, and may be made of an acrylic resin that is transparent and excellent in terms of refractive index.

In this way, the assembly can be completed only by a simple operation of the lamp installation process, the light guide plate arrangement process, the clamping member fastening process, it is possible to perform the assembly work quickly and very simply.

In addition, since there are only two components in total, except for water lamps and light guide plates, the manufacturing cost can be reduced, handling is easy, and the overall weight can be greatly reduced.

In the detailed description of the present invention described above with reference to the preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the present invention described in the claims and It will be appreciated that various modifications and variations can be made in the present invention without departing from the scope of the art.

Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

1 is an exploded perspective view illustrating a backlight unit of a conventional liquid crystal display device;

2 is a partially exploded perspective view illustrating a backlight unit of a conventional liquid crystal display device;

3 is a perspective view showing a combined backlight unit of a conventional liquid crystal display device;

4 is an exploded perspective view illustrating a backlight unit of a liquid crystal display according to an exemplary embodiment of the present invention.

5 is an exploded perspective view illustrating a backlight unit of a liquid crystal display according to an exemplary embodiment of the present invention.

6 is a perspective view illustrating a backlight unit of a liquid crystal display according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10 lamp 11: bottom chassis

12: reflection sheet 13: support pin

14 side mold 15 light guide plate

16: cover 17: reflective surface

18: composite mold 19: clamping member

20: protrusion pillar 21: light guide plate seat

22: protruding band 23: positioning protrusion

24: clip 25: guide pin

25a, 25b: hole 26: groove portion

Claims (7)

delete delete In the backlight unit comprising a lamp 10 and a light guide plate 15, The inner surface is a reflective surface 17 and a plurality of supporter pins 13 for fixing the lamp 10 are integrally formed at the bottom of the inner surface and formed of a single plastic injection molding to accommodate the lamp 10. 18 and a plurality of fastenings to the composite mold 18 side while pressing the edge portion of the light guide plate 15 to fix the light guide plate 15 disposed on the front surface of the composite mold 18 and covering the lamp 10. A clamping member 19, And a light guide plate seat 21 for seating the light guide plate 15 at edges of four front sides of the complex mold 18. 4. The liquid crystal display device according to claim 3, wherein at least two of the light guide plate seat surfaces 21 of the four sides of the composite mold 18 are provided with protrusion bands 22 for blocking the light guide plate 15 from the outside. Backlight Unit. The method of claim 3 or claim 4, wherein the plurality of light guide plate 15 to hold the position of the light guide plate 15 is fitted in at least two of the light guide plate seat surface 21 of the four sides of the composite mold 18 in the form of unevenness. The positioning unit 23 of the backlight unit of the liquid crystal display device, characterized in that formed. The backlight unit of a liquid crystal display device according to claim 3, wherein the wall of the composite mold (18) has a trapezoidal cross-sectional structure. delete

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