KR101310971B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device, wherein the liquid crystal display device according to the present invention includes a liquid crystal panel, a light source unit provided in a rear direction of the liquid crystal panel to supply light to the liquid crystal panel, and the light source unit accommodated therein. And a bottom cover disposed in parallel with a rear surface of the bottom cover, and a bottom cover connected to the bottom and bent upward in the direction of the liquid crystal panel, wherein the bottom cover includes at least one fixing protrusion for fixing the light source unit. Characterized in that more than one elastic projection is formed.

Bottom cover, light emitting diode, printed circuit board, fixing protrusion

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

1 is a cross-sectional view showing a liquid crystal display device according to the related art.

2 is a perspective view showing a liquid crystal display device according to a first embodiment of the present invention.

3 is a cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention.

4 is an enlarged perspective view of portion A of FIG. 2;

5 is an enlarged perspective view illustrating a portion B of FIG. 2.

6 is a perspective view illustrating a light source unit fastened to a bottom cover according to the first embodiment;

Figure 7 is a perspective view showing a second embodiment according to the present invention, the elastic projection formed on the side of the bottom cover.

DESCRIPTION OF REFERENCE NUMERALS

110: case top 120: liquid crystal panel

140: optical sheet 150: light source

151: printed circuit board 152: light emitting diode

160: Light guide plate 170: Reflective plate

180: bottom cover 180a: fixing protrusion

180b: elastic protrusion 181: bottom portion

182: side portion 186: end

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and in particular, a fixing means is formed inside the bottom cover to fix the printed circuit board on which the point light source is formed, thereby improving the assemblability of the liquid crystal display device and reducing the material cost of the liquid crystal display device. It relates to a liquid crystal display device.

In general, a liquid crystal display includes a liquid crystal panel in which a color filter substrate, which is an upper substrate, and a thin film transistor array substrate, which is a lower substrate, face each other, and a liquid crystal layer is filled therebetween. And a driving unit for supplying a scan signal to the liquid crystal panel and supplying image information to perform an operation of the liquid crystal panel.

In the liquid crystal panel, a plurality of gate lines and data lines are vertically and horizontally arranged to define a plurality of pixels, and each pixel is provided with a switching element and electrically connected to the gate line and the data line. In addition, the thin film transistor array substrate and the color filter substrate are each provided with a pixel electrode and a common electrode. As the image signal is applied, the liquid crystal is driven by an electric field formed between the pixel electrode and the common electrode to display an image. .

Since the liquid crystal display is a non-light emitting device that does not emit light by itself, in order to implement an image, a light source for supplying light to the liquid crystal panel is required. Accordingly, the liquid crystal display includes a back light assembly including a light source for supplying light to the liquid crystal panel and a light guide plate, an optical sheet, and the like for improving the quality of light emitted from the light source.

The light source of the backlight assembly includes a linear light source and a point light source. Representative light sources include a cold cathode fluorescent lamp (CCFL) in which electrodes at both ends are installed in a tube, and a light emitting diode (Light Emitting Diode) is a representative point light source.

Conventionally, a cold cathode fluorescent lamp is mainly used as a light source of a backlight assembly. However, in recent years, a liquid crystal display device employing a light emitting diode, which is advantageous in power consumption, weight, and luminance, is used as a light source of a backlight assembly according to the trend toward miniaturization, thinness, and light weight of liquid crystal display devices. Is growing.

Hereinafter, a structure of a general liquid crystal display device having a light emitting diode as a light source will be described with reference to the accompanying drawings.

1 is a cross-sectional view showing a cross section of a general liquid crystal display device. As shown in the drawing, a conventional liquid crystal display device includes a liquid crystal panel 20 and a light emitting diode 52 for supplying light to the liquid crystal panel 20. And a light source unit 50 formed of a printed circuit board 51 mounted on one surface of the light emitting diode 52, and at least one light incident surface facing the light source unit 50, and emitted from the light source unit 50. A light guide plate 60 to guide the light toward the liquid crystal panel 20, a bottom cover 80 to receive and protect the printed circuit board 51, the light guide plate 60, and the liquid crystal panel 20, and the light emitting diodes. And a guide panel 30 which wraps around the printed circuit board 51 and the liquid crystal panel 20 and maintains its shape. In addition, the upper and lower surfaces of the light guide plate 60 are further provided with an optical sheet 40 and a reflecting plate 70 to increase the efficiency of light incident on the liquid crystal panel 20.

However, the assembling process of the liquid crystal display device including the above work process includes a process of fixing the light source unit 50, and a bottom cover using the adhesive member 55 on the rear surface of the light source unit 50. It is made by attaching to a partial region of 80.

Therefore, the operation of attaching the light source unit 50 to the bottom cover 80 is not only cumbersome but also takes a long time. In addition, the liquid crystal display having the above configuration has a problem in that a material cost is increased by using the adhesive member 55 to fix the light source unit 50, and when the adhesive force of the adhesive member 55 is weakened, the light source unit ( There is also a problem that 50) leaves the original position.

Accordingly, an object of the present invention for solving the above problems is to form a fixing protrusion and an elastic protrusion inside the bottom cover to fix the light source unit to simplify the assembly process of the liquid crystal display device, and to reduce the material cost In providing a display device.

According to an exemplary embodiment of the present invention, a liquid crystal display device includes a liquid crystal panel, a light source unit provided in a rear direction of the liquid crystal panel to supply light to the liquid crystal panel, and a rear surface of the liquid crystal panel accommodating the light source unit. And a bottom cover including a bottom portion arranged in parallel and a side portion connected to the bottom portion and bent upward in the liquid crystal panel direction. In this case, the bottom cover is characterized in that at least one fixing protrusion and at least one elastic protrusion for fixing the light source unit is formed.

The light source unit includes a plurality of light emitting diodes and a printed circuit board on which the light emitting diodes are mounted.

The fixing protrusion may include a protrusion formed to protrude from a portion of an upper edge portion of the bottom cover, and a locking jaw formed at an end of the protrusion. The opposite side of the surface on which the light emitting diode is mounted on the printed circuit board is in contact with the side surface of the bottom cover, and the locking projection of the fixing protrusion covers a portion of the surface on which the printed circuit board is mounted.

The elastic protrusion may cut one region of the bottom cover, and then bend the cut portion upward to form an end portion of the cut portion substantially parallel to the bottom surface portion. An end portion of the elastic protrusion is in contact with a surface on which the light emitting diode of the printed circuit board is mounted to fix the printed circuit board.

In this case, the elastic protrusion may be formed on the bottom or side surface portion of the bottom cover, the distance between the end of the elastic protrusion and the side of the bottom cover side portion corresponding to the side of the end of the elastic protrusion is substantially the thickness of the printed circuit board It is characterized by the same.

The fixing protrusion and the elastic protrusion may be integrally formed with the bottom cover.

The liquid crystal display according to the present invention further includes a light guide plate disposed on a rear surface of the liquid crystal panel and having at least one light incident surface facing the light source unit, and guiding light emitted from the light source unit toward the liquid crystal panel. It features.

Hereinafter, a liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a perspective view of a liquid crystal display according to a first exemplary embodiment of the present invention, and FIG. 3 is a cross-sectional view. In the present embodiment, for convenience of explanation, the image display direction of the liquid crystal display device is described as the upper side and the opposite direction as the lower side.

In the following description, a case where a light emitting diode (LED) is applied as a light source will be described as an example. However, the present invention is not limited thereto, and the technical idea of the present invention may be applied to other lamps as necessary.

As shown in FIG. 2, the liquid crystal display device 100 includes a liquid crystal panel 120 for forming an image, a guide panel 130 for supporting an edge of the liquid crystal panel 120, and a liquid crystal panel 120. The optical sheet 140 provided on the rear surface, the light guide plate 160 disposed behind the optical sheet 140, the light source unit 150 disposed on the side surface of the light guide plate 160, and the rear side of the light guide plate 160. It includes a reflector plate 170 disposed in, a bottom cover 180 for accommodating the light source unit 150 therein, and a case top 110 for fixing the front surface of the liquid crystal panel 120.

The case top 110 supports the front edge of the liquid crystal panel 120 and is provided in the form of a frame having an empty inside. The case top 110 has a display window exposing the effective surface (display area) of the liquid crystal panel 120.

The liquid crystal panel 120 is formed between the transparent first substrate 121, the second substrate 122 facing the first substrate 121, and the first substrate 121 and the second substrate 122. It includes a liquid crystal layer (not shown). The liquid crystal panel 120 is arranged in a matrix form of the liquid crystal cells forming a pixel unit, and forms an image by adjusting the light transmittance of the liquid crystal cells in accordance with the image signal information transmitted from the driver (not shown).

The first substrate 121 is a thin film transistor substrate on which a thin film transistor is formed. A plurality of gate lines and a plurality of data lines defining pixels are formed in a matrix form, and thin film transistors are formed at intersections of the gate lines and the data lines. Film Transistor (TFT) is formed.

The second substrate 122 is a color filter substrate and includes a color filter and a common electrode, which are formed by repeating red, green, and blue on the black matrix. The common electrode is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The second substrate 122 has a smaller area than the first substrate 121.

The signal voltage transmitted from the driving unit (not shown) for driving the liquid crystal panel is applied between the pixel electrode and the common electrode of the second substrate 122 through the thin film transistor, and the liquid crystal between the pixel electrode and the common electrode is the signal voltage. The light transmittance is determined according to the alignment.

Although not shown in FIG. 2, referring to FIG. 3, polarizers 123a and 123b are provided on the front and rear surfaces of the liquid crystal panel 120 to polarize light transmitted through the liquid crystal panel 120. The polarizing plates provided on the front surface of the liquid crystal panel 120 and the polarizing plates 123a and 123b provided on the rear surface of the liquid crystal panel 120 are disposed so that the polarization axes cross vertically.

The guide panel 130 is formed along the edge of the liquid crystal panel 120 and has a substantially rectangular frame shape. The guide panel 130 supports the liquid crystal panel 120 spaced apart from the optical sheet 140. The guide panel 130 accommodates the optical sheet 140, the light guide plate 160, the light source 150, and the reflecting plate 170 therein in combination with the outer surface of the bottom cover 180 to be described later.

The rear surface of the liquid crystal panel is provided with an optical sheet 140. The optical sheet 140 is for efficiently supplying the light emitted from the light source unit 150 to the liquid crystal panel, and includes a protective sheet 141, a prism sheet 143, and a diffusion sheet 145 sequentially stacked from the top. do.

The diffusion sheet 145 serves to diffuse the light from the light source unit 150 to supply the liquid crystal panel 120, and the prism sheet 143 transmits the light diffused from the diffusion sheet 145 to the upper liquid crystal panel 120. It collects light in a direction perpendicular to the plane of). The uppermost protective sheet 141 protects the prism sheet 143 that is weak to scratches.

The light guide plate 160 is disposed on the rear surface of the liquid crystal panel 120 to guide light generated from the light source 150 to the rear surface of the liquid crystal panel 120. The light guide plate 160 may have a pattern such that a light incident surface receiving light from the light source 150, a light emitting surface facing the rear surface of the liquid crystal panel 120, and light irradiated from the light source 150 to the incident surface proceed to the light emitting surface. Has a rear surface formed. The rear surface is disposed in contact with the reflecting plate 170.

The light source unit 150 is disposed on one side of the light guide plate 160. The light source unit 150 according to the present invention includes a plurality of light emitting diodes 152 arranged in one row, and a printed circuit board 151 mounted on one surface of the light emitting diodes 152.

The printed circuit board 151 has a plate shape extending in one direction and is disposed along at least one side of the light guide plate 160. A plurality of light emitting diodes 152 are mounted on one surface of the printed circuit board 151, and circuit wirings are provided to transfer power received from a light source driver (not shown) to the light emitting diodes 152. The light emitting diodes 152 supply white light to the light guide plate 160 and are disposed at regular intervals. Each of the light emitting diodes 152 may include sub light emitting diodes emitting red, green, and blue light, respectively, and light supplied from the sub light emitting diodes is mixed to supply white light.

When the surface on which the light emitting diodes 152 of the printed circuit board 151 of the light source unit 150 are mounted is referred to as a front surface, an opposite surface on which the light emitting diodes 152 are not mounted, that is, a rear surface of the bottom cover 180 will be described later. It is provided in contact with the side portion 182. At this time, the light source unit 150 according to the present invention is fixed by the fixing protrusion (180a) and the elastic protrusion (180b) formed in the bottom cover 180 to be described later, as shown in FIG.

The reflective plate 170 is disposed under the light guide plate 160. The reflector plate 170 reflects the light incident to the lower part of the light guide plate 160 among the light from the light emitting diode 152 so as to face upward. The reflector plate 170 may be made of polyethylene telephthalate (PET) or polycarbonate (PC), and may be coated with silver or aluminum.

The bottom cover 180 is disposed on the rear surface of the reflector plate 170. The bottom cover 180 accommodates the above-described optical sheet 140, the light guide plate 160, the light source unit 150, and the reflector plate 170 therein, and a bottom portion 181 disposed in parallel with the rear surface of the liquid crystal panel 120. And a side portion 182 connected to the bottom portion 181 and bent upward in the liquid crystal panel direction.

As shown in FIGS. 2 and 3, the bottom cover 180 has one or more fixing protrusions 180a and one or more elastic protrusions 180b for fixing the light source unit 150.

4 and 5 are enlarged views of the fixing protrusion 180a and the elastic protrusion 180b of the bottom cover 180, respectively. FIG. 4 is an enlarged perspective view of portion A of FIG. 2, and FIG. 2 is an enlarged perspective view of part B of FIG. 2.

6 is a perspective view showing the light source unit 150 fastened to the bottom cover 180 according to the present invention.

Hereinafter, the fixing protrusion 180a and the elastic protrusion 180b will be described in detail with reference to the accompanying drawings.

The fixing protrusion 180a is formed to fix the light source unit 150, particularly the printed circuit board 151.

As shown in FIG. 4, the fixing protrusion 180a includes a protrusion 183 formed to protrude in a partial region of the side portion 182 of the bottom cover 180 and a hook shape formed at an end of the protrusion 183. It consists of a locking step 184 provided as.

Here, the rear surface of the printed circuit board 151 is disposed in contact with the side surface portion 182 of the bottom cover 180. The protrusion 183 of the fixing protrusion 180a is formed by protruding a portion of the bottom cover 180 to surround a portion of the upper edge of the printed circuit board 151.

A hooking jaw 184 formed in a hook shape is formed at an end of the protrusion 183 so as to cover a portion of the front surface of the printed circuit board 151 on which the light emitting diode 152 is mounted, and to bottom the printed circuit board 151. The side surface 182 of the cover 180 is fixed.

At this time, the distance between the inner surface of the side surface portion 182 of the bottom cover 180 and the locking jaw 184 of the end portion of the protrusion 183 is substantially the same as the thickness W of the printed circuit board 151. In addition, the distance between the inner surface of the bottom portion 181 of the bottom cover 180 and the bent portion of the protrusion 183 is substantially the same as the height H of the printed circuit board 151. By forming the fixing protrusion (180a) as described above it is possible to prevent the departure of the light source unit 150 and to support without flow.

The protrusion 183 is formed by cutting a region of the side portion 182 of the bottom cover 180, and then bending the cut portion in an inner direction perpendicular to the side portion 182. At this time, the cutout portion is bent inwardly to form a protrusion 183, and the end of the protrusion 183 is bent back toward the bottom portion 181 to form a locking step 184.

The protruding portion 183 may be formed on the side surface portion 182 of at least one side of the bottom cover 180 on which the light source unit 150 is disposed. However, of course, the protrusion 183 may be formed in plural in appropriate positions as necessary.

Referring to FIG. 5, the elastic protrusion 180b cuts a region of the bottom portion 181 and then upwardly bends the cut portion at a set angle and number of times so that the end portion 186 of the cut portion is the bottom portion 181. And are formed substantially parallel to the. The bending angle and the number of times can be variously adjusted, but after bending at an acute angle of 90 degrees or less with respect to the bottom portion 181, bending the end portion 186 again at an angle parallel to the bottom portion 181. desirable.

That is, the end portion 186 of the cutout portion protrudes upward from the bottom portion 181 at regular intervals, and the top surface of the end portion 186 is formed to be substantially parallel to the bottom portion 181. Therefore, even if the end portion 186 receives a force in the direction of the bottom portion 181, the restoring force is returned to its original state to have an elastic force.

In this case, the distance W between the side surface of the end 186 of the elastic protrusion 180b and the side surface 182 of the bottom cover 180 corresponding to the side surface of the end 186 of the elastic protrusion 180b is the printed circuit. It is substantially the same as the thickness of the substrate 151. Therefore, the side surface of the end portion 186 of the elastic protrusion 180b is in contact with the front surface on which the light emitting diode 152 of the printed circuit board 151 is mounted to fix the printed circuit board 151.

The elastic protrusions 180b may be formed near both ends of the printed circuit board 151, that is, near the corners of the bottom cover 180 in order to efficiently fix the printed circuit board 151 formed in the longitudinal direction. .

Here, two elastic protrusions 180b may be preferably formed near the edge of the bottom cover 180, but may be formed in singular or plural as necessary, and various positions may be changed.

The fixing protrusion 180a and the elastic protrusion 180b are formed integrally with the bottom cover 180. As shown, both the fixing protrusion 180a and the elastic protrusion 180b are formed by cutting and bending one region of the bottom cover 180 and have the same material as the bottom cover 180.

Looking at the fastening method of the light source unit 150 according to the present invention with reference to Figures 4 and 5, first, a part of the upper edge of the printed circuit board 151 is fastened to the fixing projection (180a). Then, the lower edge portion of the printed circuit board 151 is pushed in the side direction of the bottom cover 180.

At this time, since the elastic protrusion 180b is bent to form an acute angle from the bottom portion 181 in the upper direction, the printed circuit board 151 is moved along the bent acute angle. Therefore, when a force is applied to the lower edge of the printed circuit board 151 in the direction of the side portion 182 of the bottom cover 180, the elastic protrusion 180b is pressed down toward the bottom portion 181 of the bottom cover 180. The printed circuit board 151 is disposed in contact with the side portion 182 of the bottom cover 180.

After the printed circuit board 151 is disposed on the side portion 182 of the bottom cover 180, the elastic protrusions 180b, which are pressed down to the bottom direction, are restored to their original state by elasticity and rise upward. Accordingly, the side surface of the end 186 of the elastic protrusion 180b is in contact with the printed circuit board 151 to support the printed circuit board 151.

6 is a perspective view showing a state in which the light source unit 150 is fastened to the bottom cover of the above structure. As shown, the printed circuit board 151 is fixed by the fixing protrusion 180a and the elastic protrusion 180b.

Figure 7 shows a second embodiment according to the present invention, it shows that the elastic projection (B ') is formed on the side portion 182 of the bottom cover 180. In the present embodiment, only portions distinguishing from the above-described first embodiment will be described, and descriptions omitted or summarized will follow the first embodiment and known techniques. In addition, for the convenience of description, the same reference numerals refer to the same elements.

In the present exemplary embodiment, the elastic protrusion B 'is formed on the side portion 182 instead of the bottom portion 181 of the bottom cover 180. After cutting one region of the side portion 182 of the bottom cover 180, the cut portion is bent inwardly at a set angle and number of times so that the end portion 186 'of the cut portion is substantially parallel to the side portion 182. do.

The bending angle and the number of times can be adjusted in various ways, but after bending at an acute angle of 90 degrees or less with respect to the side portion 182, it is preferable to bend the end 186 'again at an angle parallel to the side portion 182. Do.

That is, the end portion 186 ′ of the cutout portion protrudes in the inner direction at regular intervals from the side portion 182, and the upper surface of the end portion 186 ′ is formed to be substantially parallel to the bottom portion 181. As a result, even if the end portion 186 'receives a force toward the side portion 182, a restoring force that returns to its original state is applied to have an elastic force.

Therefore, the printed circuit board 151 can be fixedly supported without flow in the same principle as the first embodiment.

In this case, the elastic protrusion B 'may be symmetrically formed at a corresponding position of the other side portion of the bottom cover 180 parallel to the side portion 182 on which the elastic protrusion B' is formed.

By the bottom cover having such a structure, the light source part is restricted and flow is stably supported. In addition, the present invention has the advantage that the light source unit can be easily detached in a manner that the elastic projection is pressed in the downward direction. In particular, the present invention does not need to use a separate adhesive member as compared to the prior art can reduce the manufacturing cost. In addition, since the bottom cover and the side portion of the bottom portion or side portion are formed by cutting and bending the bottom cover, the fixing protrusion and the elastic protrusion can be easily formed, thereby reducing the manufacturing time and the assembly time of the liquid crystal display device. Can improve.

As described in detail above, the present invention simplifies the assembly process of the liquid crystal display by fixing the printed circuit board to the bottom cover by forming one or more fixing protrusions and one or more elastic protrusions inside the bottom cover, and assembling process time. Has the advantage of shortening.

In addition, by reducing the use of the adhesive member has the effect of reducing the material cost of the liquid crystal display device, there is an advantage that can be secured to the printed circuit board by the fixing projections and the elastic projections, provided in the printed circuit board It is possible to ensure the stability of the point light source.

Claims (16)

A liquid crystal panel; A light source unit provided in a rear direction of the liquid crystal panel to supply light to the liquid crystal panel, wherein the light source includes a plurality of light emitting diodes and a printed circuit board mounted on one surface of the light emitting diodes; And A bottom cover accommodating the light source unit and having a bottom portion arranged in parallel with a rear surface of the liquid crystal panel, and a side portion connected to the bottom portion and bent upward in the direction of the liquid crystal panel; The bottom cover may include at least one fixing protrusion and at least one elastic protrusion formed integrally with the bottom cover by cutting a portion of the bottom cover to fix the printed circuit board of the light source unit. Device. delete The method of claim 1, And the fixing protrusion includes a protrusion formed to protrude from a portion of the side surface of the bottom cover, and a locking jaw formed at an end of the protrusion. The method of claim 3, And the protruding portion is formed by cutting one region of the side portion, and then bending the cut portion in an inward direction perpendicular to the side portion. The method of claim 3, And the locking jaw is formed by bending an end portion of the protruding portion toward the bottom portion. The method of claim 3, The opposite side of the surface on which the light emitting diode is mounted on the printed circuit board is in contact with the side surface of the bottom cover, and the locking projection of the fixing protrusion covers a portion of the surface on which the light emitting diode is mounted on the printed circuit board. Liquid crystal display characterized in that. The method of claim 1, And the elastic protrusion cuts one region of the bottom portion, and then bends the cut portion upward, wherein an end portion of the cut portion is parallel to the bottom portion. The method of claim 7, wherein And the elastic protrusions are bent to form an acute angle with respect to the bottom portion, and the ends are bent again at an angle parallel to the bottom portion. The method of claim 7, wherein And an end portion of the elastic protrusion in contact with a surface on which the light emitting diode of the printed circuit board is mounted to fix the printed circuit board. delete delete The method of claim 7, wherein And a distance between an end portion of the elastic protrusion and a side surface of the bottom portion of the elastic protrusion and the bottom cover side portion corresponding to the thickness of the printed circuit board. delete The method of claim 1, And a light guide plate disposed on a rear surface of the liquid crystal panel, the light guide plate having at least one light incident surface facing the light source unit, and guiding light emitted from the light source unit toward the liquid crystal panel. The method of claim 1, And the elastic protrusion cuts one region of the side portion, and then bends the cut portion upward, wherein an end portion of the cut portion is parallel to the side portion. 16. The method of claim 15, And the elastic protrusions are bent to form an acute angle with respect to the side portion, and the end portion is bent again at an angle parallel to the side portion.

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