KR101069251B1 - backlight unit - Google Patents

Abstract

The present invention relates to a backlight unit, the backlight unit comprising: a case having a locking portion formed on an inner surface thereof; A reflective plate mounted in the case, a plurality of light emitting lamps disposed on the reflecting plate, an upper support plate disposed on the plurality of light emitting lamps and seated on and supported by a latching portion of the case, and laminated on the upper support plate. And a diffuser plate and an optical sheet, and a liquid crystal display panel disposed on the optical sheet. The assembly of the liquid crystal display module is increased by changing the shape of the case in which the upper support plate is in contact, thereby increasing the bonding strength between the case and the upper support plate. Or it can prevent the fall of the grade by torsion at the time of fastening to a system.

Case, locking part, lower support plate, upper support plate, liquid crystal display panel

Description

Backlight Unit {BACKLIGHT UNIT}

1 is a schematic diagram of a direct backlight unit structure according to the prior art;

2 is an enlarged view of a portion A of FIG. 1 in the direct type backlight unit according to the prior art;

3 is a schematic diagram of a state in which a diffuser plate, an optical sheet, and a liquid crystal display panel are mounted on a direct backlight unit according to the prior art;

4 is a schematic diagram of a direct backlight unit structure according to the present invention;

5 is an enlarged view of a portion B of FIG. 4 in the direct type backlight unit according to the present invention;

6 is a schematic view of a state in which a diffuser plate, an optical sheet, and a liquid crystal display panel are mounted in a direct type backlight unit according to the present invention;

7 is an enlarged view of a portion C of FIG. 6 in the direct type backlight unit according to the present invention;

-Code description of main parts of drawing-

111: case 111a: locking portion

113: reflector plate 115: lower support plate

117: light emitting lamp 119: upper support plate                 

121, 121a: fastener 123: diffuser plate

125: optical sheet 131: liquid crystal display panel

131: liquid crystal display panel

The present invention relates to a backlight unit, and more particularly to a backlight unit that can improve the strength of the module structure of the liquid crystal display device by changing the shape of the cover bottom corner (cover bottom corner).

Among the many flat panel displays developed to date, liquid crystal displays are widely used in a wide variety of applications ranging from laptops, monitors, televisions, spacecraft, and aircraft.

There are three main types of liquid crystal displays, a liquid crystal display panel, a driving circuit unit, and a backlight unit.

Here, the liquid crystal display panel is bonded to the substrate on which the TFT array is formed and the substrate on which the color filter is formed to be maintained at a predetermined interval, and a liquid crystal layer is formed by injecting liquid crystal between the two substrates. Polarizers are attached to the outside of the two substrates, respectively.

In addition, the driving circuit unit includes various circuit elements and a printed circuit board (PCB).                         

The backlight unit includes a light emitting lamp, various sheets, a support mold, and the like.

In the liquid crystal display device composed of the components as described above, the liquid crystal liquid crystal display panel is responsible for displaying an image by adjusting the amount of transmitted light, and the driving circuit unit is configured to receive various signals transmitted from the driving system. It applies a signal to the liquid crystal display panel and controls the signal. In addition, the backlight unit is used as a dimming device for evenly irradiating light on the entire liquid crystal display panel. The mounting of the backlight is inefficient in terms of thickness, weight, and power consumption, and much research is still being conducted.

Since the display by the liquid crystal display panel itself is non-luminescent, it cannot be used where there is no light. Therefore, the backlight for uniformly irradiating the display surface for the purpose of making it possible to use in a dark place to compensate for this disadvantage.

Since the backlight is a light source of the liquid crystal display device, it is required to emit the brightest light with the minimum power, and maintains the same fluorescent light as a line to the surface brightness by maintaining the same brightness to every corner of the liquid crystal display device.

Such a backlight is a direct type in which the light emitting lamp irradiates light directly from the rear side of the liquid crystal display device to the front side according to the position of the light emitting lamp, and the light is located on the side of the light guide plate. Side type (Side Type) and part of the side type to face the front while passing through the light emitting lamp is located on only one side by using the inclined light guide plate, half light from one side passes through the inclined light guide plate It can be classified into an edge type that faces.

The side backlight may include a light emitting lamp for emitting light, a reflective sheet for reducing light loss, a lamp cover surrounding the light emitting lamp, and light exiting to the rear surface of the light guide plate in the direction of the light guide plate. The reflection sheet and the light toward the front have to be changed in the medium so that dots are formed on the bottom surface of the light guide plate through dot screen printing process, and small glass beads are included in the dots. Light is scattered on the glass bead surface, and the light guide plate through which the scattered light passes, and the light scattered through the printed light guide plate directly enters the eye, thus minimizing the shape of the pattern printed on the light guide plate. After passing through the diffusion sheet and the diffusion sheet, the luminance is rapidly decreased to focus the luminance again. It consists of a prism sheet to increase the brightness, a protection sheet to prevent contamination from external impact or foreign material inflow, and a mold frame that finally supports the above components. .

The side-type backlight configured as described above has a problem in that the light is distributed to the entire surface by using the light guide plate, and the luminance is low because the light emitting lamp is installed outside the light guide plate and light passes through the light guide plate.

In addition, high optical design and processing techniques for the light guide plate are required for uniform distribution of light intensity. Therefore, it is mainly used in thin liquid crystal display devices in which thickness is important, such as notebook computers.                         

On the other hand, the conventional direct type backlight used for a large screen and high brightness rather than the thickness of the liquid crystal display device does not require a light guide plate, and the light emitting lamp uses a cold cathode fluorescent lamp (CCFL), and the shape of the light emitting lamp A plurality of straight tubes or light emitting lamps such as a U-shaped tube or a W-shaped tube are provided.

In the direct backlight, the liquid crystal panel and the liquid crystal panel are mounted in a case. A backlight housing is provided in the case. A light emitting lamp is provided in the backlight housing, and a light blocking plate, a transparent film, and a diffusion plate are sequentially formed on the light emitting lamp. The lower portion of the backlight housing is provided with a reflective plate formed of aluminum.

In order to adjust the luminance distribution of the light emitted from the light emitting lamp configured as described above, a light-shielding plate having a dot printed on a polyethylene film or the like along the shape of the light emitting lamp is disposed on the light emitting lamp, and a transparent film is disposed on the light blocking plate, and the transparent A diffuser plate is disposed on the film. The transparent film forms an optical space between the diffusion plate and the light emitting lamp.

Therefore, since the light passing through the light shielding plate is incident on the diffusion plate at a wide range of angles, the light diffusing property can be improved. The diffusion plate uses a coating of an optical acid material on both sides of a film made of a transparent resin or the like. The backlight configured as described above is provided in a case in which a liquid crystal display panel, a printed circuit board, or the like is mounted.

In addition, when the AC power is applied by connecting the plurality of light emitting lamps in parallel to the flat plate, only a few lamps emit light, so the light emitting lamps cannot be driven by parallel connection, so each inverter is a separate power supply device for each light emitting lamp. It should be driven by (Invertor). That is, each light emitting lamp and the power supply are individually connected.

Conventional direct-type backlight has a high light utilization efficiency, which has led to the trend toward larger and larger screens of liquid crystal display devices. Direct type backlight equipped with an external Electrode Fluorescent Lamp (EEFL) is used. The external electrode fluorescent lamps may be driven by arranging a plurality of the external electrode fluorescent lamps in parallel in a plane.

The conventional direct backlight unit structure will be described with reference to FIGS. 1 to 3 as follows.

1 is a schematic diagram of a direct backlight unit structure according to the prior art.

2 is an enlarged view of a portion A of FIG. 1 in the direct backlight unit according to the related art.

3 is a schematic diagram of a state in which a diffusion plate, an optical sheet, and a liquid crystal display panel are mounted on a direct backlight unit according to the related art.

1 and 2, a direct backlight unit according to the related art includes a cover bottom 11 on which elements constituting a backlight are mounted, and a reflecting plate 13 mounted on a bottom surface of the case 11. ), A support side bottom 115 provided at regular intervals above the reflector plate 13, and a plurality of light emitting lamps 17 mounted above the lower support plate 15 in the case 11. ) And a support side top 19 installed at regular intervals above the light emitting lamps 17.

Here, both ends of the upper support plate 19 is primarily supported by the tapered side portions of the case 11.

In addition, as shown in FIG. 3, the diffusion plate 23 and the optical sheet 25 are sequentially stacked on the upper support plate 119 of the backlight unit having the above configuration at regular intervals, and the optical sheet 25 is provided. A liquid crystal display panel 31 which displays an image by controlling light transmitted therethrough is installed, and a plurality of fixing fasteners 21 are inserted through the case 11 and the upper support plate 19 to fix and fix them. It is.

Looking at the path of the light transmitted to the liquid crystal display panel through the direct type backlight unit according to the prior art configured as described above, most of the light emitted through the light emitting lamps 17 to the diffusion plate 23 The light is directly incident and part of the light is reflected by the reflecting plate 13 and is incident on the diffusion plate 23. At this time, the reflector 13 prevents the loss of light directed to the rear surface.

In addition, the diffusion plate 23 scatters incident light and enters the optical sheet 25 with uniform light. In addition, the optical sheet 25 collects the light incident through the diffusion plate 23 to make the brightness as bright as possible, and then enters the liquid crystal display panel 31 on the screen of the liquid crystal display panel 31. To be displayed.                         

However, as described above, according to the backlight unit according to the prior art, the case and the upper support plate is fixed to the center portion by a plurality of supports.

Since a plurality of supports are fastened between the case and the upper support plate, the coupling strength between the case and the upper support plate becomes stronger, but there is no separate fastening portion at the edge of the upper support plate, and both ends of the upper support plate contact the side portions of the case. By being supported, a phenomenon in which the edge portion of the upper support plate is easily bent may occur.

Therefore, fastening a plurality of supports only to the center portion of the case and the upper support plate can be seen that the simple fixing side is stronger than the reinforcing side of the backlight unit structure.

Therefore, the backlight unit according to the related art is disadvantageous in terms of the torsional strength of the entire liquid crystal display module and the stability of the mechanism.

Accordingly, the present invention has been made to solve the above problems according to the prior art, by changing the shape of the case in which the upper support plate is contacted to increase the coupling strength of the case and the upper support plate when assembling the liquid crystal display module or fastening to the system It is an object of the present invention to provide a backlight unit capable of preventing deterioration of quality due to torsion.

According to an aspect of the present invention, there is provided a backlight unit including: a case having a locking portion formed at an inner side thereof; A reflecting plate mounted in the case; A plurality of light emitting lamps disposed on the reflecting plate; An upper support plate disposed on the plurality of light emitting lamps, the upper support plate being seated on and supported by the engaging portion of the case; A diffusion plate and an optical sheet stacked on the upper support plate; And a liquid crystal display panel disposed on the optical sheet.

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

4 is a schematic diagram of a direct backlight unit structure according to the present invention.

5 is an enlarged view of a portion B of FIG. 4 in the direct type backlight unit according to the present invention.

6 is a schematic diagram of a state in which a diffuser plate, an optical sheet, and a liquid crystal display panel are mounted in a direct type backlight unit according to the present invention.

7 is an enlarged view of a portion C of FIG. 6 in the direct type backlight unit according to the present invention.

4 and 5, the direct type backlight unit according to the present invention is mounted on a cover bottom 111 on which elements constituting a backlight are mounted, and on the bottom surface or the entire inner surface of the case 111. The reflective plate 113, the support side bottom 115 installed at regular intervals on the reflective plate 113, and the lower support plate 115 in the case 111 at regular intervals. And a plurality of light emitting lamps 117 to be provided, and a support side top 119 installed at regular intervals above the light emitting lamps 117.                     

In this case, as illustrated in FIG. 5, a latching portion 111a is formed at a side portion of the case 111 so that both ends of the upper support plate 119 are seated and supported.

In addition, the reflective plate 113 mounted on the bottom surface of the case 111 may be formed to be positioned not only on the bottom surface of the case 111 but also to the side surface thereof.

On the upper support plate 119 of the backlight unit having the above configuration, as shown in FIG. 6, the diffusion plate 123 and the optical sheet 125 are sequentially stacked at regular intervals, and on the optical sheet 125 A liquid crystal display panel 131 which displays an image by adjusting the transmitted light is provided, and a plurality of fastening holes 121 are inserted through the case 111 and the upper support plate 119 from the case or the upper support plate side. To fix them. Here, the plurality of fixing fasteners 121 may use a screw or another fastening means (not shown).

In addition, both ends of the upper support plate 119, as shown in Fig. 7, the fastening portion 121a separate from the locking portion 111a of the case 111, for example, a screw or other fastening means It is fixed by binding.

Looking at the path of the light transmitted to the liquid crystal display panel through the direct type backlight unit according to the present invention configured as described above, first, most of the light emitted through the light emitting lamps 117 is the diffusion plate 123 The light is directly incident on the light, and a part of light is reflected by the reflector 113 and is incident on the diffuser plate 123. In this case, the reflective plate 113 prevents the loss of light directed to the rear surface.

In addition, the diffusion plate 125 scatters the incident light and enters the optical sheet 127 with uniform light. In addition, the optical sheet 125 collects light incident through the diffusion plate 123 to make the brightness as bright as possible, and then enters the liquid crystal display panel 131 to screen the screen of the liquid crystal display panel 131. To be displayed.

As described above, according to the backlight unit according to the present invention, both ends of the upper support plate may be seated and supported by changing the shape of the case in which both ends of the upper support plate are in contact, that is, by forming a locking part. It is possible to reinforce the strength of the case itself as well as to fasten the fastening fasteners from the case to the upper support plate, thereby increasing the torsional strength and structural strength of the entire liquid crystal display module, thereby ensuring stable quality.

On the other hand, while described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications of the present invention without departing from the spirit and scope of the invention described in the claims below And can be changed.

Claims (6)

A case having a locking portion formed on an inner side thereof; A reflecting plate mounted in the case; A plurality of light emitting lamps disposed on the reflecting plate; A lower support plate disposed between the reflective plate and the plurality of light emitting lamps; An upper support plate disposed on the plurality of light emitting lamps, the upper support plate being seated on and supported by the engaging portion of the case; Fixing fasteners are fastened to the center portion of the case and the upper support plate, the engaging portion of the case and the edge of the upper support plate; A liquid crystal display panel disposed on the upper support plate; And And a diffuser plate and an optical sheet disposed between the upper support plate and the liquid crystal display panel. The backlight unit of claim 1, wherein both ends of the upper support plate are supported by being seated on the engaging portion of the case. delete The backlight unit of claim 1, wherein a fixing fastener is fastened to the case and the upper support plate. delete delete

Images