KR20010063244A - Direct lighting type liquid crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal display device is provided to improve the brightness of the liquid crystal display device by preventing the light from being re-incident into a lamp or another lamp. CONSTITUTION: A liquid crystal display device comprises a mold frame(110). A reflective plate(120) is received in a receiving space of the mold frame(110) so as to upwardly reflect the light. A lamp unit(130) is installed at an upper portion of the reflective plate(120) so as to emit the light. A dispersing plate(150) is installed at an upper portion of the lamp unit(130) so as to uniformly disperse the light generated from the lamp unit(130). A bottom chassis(160) is coupled to a lower side of the mold frame(110) so as to support the reflective plate(120) and the lamp unit(130). A liquid crystal panel(170) is installed at an upper portion of the dispersing plate(150). A top chassis(180) is formed on an upper portion of the liquid crystal panel(170).

Description

Direct type liquid crystal display {Direct lighting type liquid crystal display}

The present invention relates to a direct type liquid crystal display device, and more particularly, in order to prevent the light emitted from each lamp from being re-entered into its own lamp or incident to another lamp adjacent to the lamp, to prevent the loss of light. The present invention relates to a direct-type liquid crystal display device in which light reflection protrusions are formed in a predetermined portion, and light blocking protrusions are formed in predetermined portions between lamps to increase light utilization efficiency.

CRT (Cathode Ray Tube), one of the display devices that are generally used, is mainly used for monitors such as TVs, measuring devices, and information terminal devices.However, due to the weight and size of CRT itself, Could not respond actively to demands.

In order to replace the CRT, liquid crystal display devices having advantages such as small size, light weight, and low power consumption have been actively developed, and in recent years, functions have been improved enough to perform a role as a flat panel display device. As it is used not only for monitors, but also for monitors and large information displays of desktop computers, the demand for liquid crystal displays is continuously increasing.

Since most of the liquid crystal display devices are light-receiving devices that display images by controlling the amount of light coming from the outside, a separate light source for illuminating the LCD panel, that is, a backlight assembly, is required. It is divided into edge type and direct type according to the location where the unit is installed.

In the double-edge method, the lamp unit is installed on the side of the light guide plate for guiding the light, and the lamp unit covers a lamp emitting light, a lamp holder inserted at both ends of the lamp to protect the lamp, and an outer circumferential surface of the lamp, and one side It is provided with a lamp reflector plate fitted to the side of the light guide plate to reflect the light emitted from the lamp toward the light guide plate.

The edge method in which the lamp unit is installed on the side of the light guide plate is applied to a relatively small liquid crystal display device such as a monitor of a laptop computer and a desktop computer, and has good uniformity of light, a long service life, and a liquid crystal. It is advantageous to thin the display device.

On the other hand, as the size of the liquid crystal display device began to increase in size to 20 inches or more, a direct development method began to focus on directly directing the LCD panel by arranging a plurality of lamps in a row on the lower surface of the diffusion plate.

Such a direct type liquid crystal display device includes a mold frame having a storage space penetrated from an upper surface to a lower surface, a bottom chassis which is fastened to the lower surface of the mold frame to close the storage space, and is installed on the base surface of the storage space to provide light. Reflector reflecting in the direction, the lamp unit is installed on the upper surface of the reflecting plate to emit light, the diffusion plate is installed on the upper part of the lamp unit spaced apart from the lamp unit by a predetermined interval, the diffuser plate to diffuse the light emitted from the lamp unit, the upper part of the diffusion plate It consists of a liquid crystal panel placed on the surface, and a top chassis covered on the upper surface of the liquid crystal panel to support the liquid crystal panel.

As shown in FIG. 1, the reflecting plate 20 installed on the base surface of the storage space is a flat plate having a flat surface on which the lamp unit is placed, and a plurality of lamp units are installed along the longitudinal direction of the reflecting plate 20 at predetermined intervals. And the light emitting lamps L1, L2, L3 and the lamps L1, L2, L3 are inserted at both ends to space the gap between the reflector 20 and the lamps L1, L2, L3 by a predetermined distance. And a lamp holder (not shown) that protects the lamps L1, L2, L3.

When a plurality of lamps L1, L2, L3 are installed on the upper surface of the reflecting plate 20 formed as described above, as shown in FIG. 1, some of the light emitted from the lamp (for example, L1) may be disposed in the lamp ( The light is re-incident to L1) or incident to and absorbed by other adjacent lamps L2 and L3, resulting in light loss.

In order to explain this in more detail, in FIG. 1, the amount of light lost by the light emitted from the lamp L1 is re-entered into its lamp L1 or is incident to another lamp L2 and L3 adjacent thereto. The description is as follows.

Here, Table 1 shows that the diameter of the lamp L1 is 2.6Φ, the interval between the lamps L1, L2, L3 is 30 mm, and the height from the reflecting plate 20 to the lower surface of the lamp L1 is 1.27 mm. It is written on the assumption that light is emitted only in the center of the lamp L1.

TABLE 1

division Contents Angle A Light emitted from L1 is directly incident to L2 4.96 ° B Light emitted from L1 is incident to L2 by the reflection of the reflector 2.5 ° B Light emitted from L1 is incident to L3 by the reflection of the reflector 5.04 ° D Light emitted from L1 is re-injected into L1 by the reflection of the reflector 14.7 °

Based on Table 1, the amount of light that is emitted from one lamp, that is, the lamp L1, and then enters the lamp L1, the lamp L2, the lamp L3, and is lost is expressed by Equation 1.

<Equation 1>

{(27.2 ° × 2) ÷ 360 °} × 100 ≒ 15.1%

In Equation 1, 27.2 ° is the sum of the angles of A, B, C, and D in Table 1, and 360 ° is the angle of the entire lamp. Here, 27.2 ° is the angle of light incident on the lamp L1, lamp L2, lamp L3 from one side of the lamp L1, so 27.2 ° should be multiplied by 2 to calculate the light lost in the entire lamp L1.

Therefore, since each of the lamps installed on the upper surface of the reflecting plate is incident on another lamp adjacent to it or re-entered into its own lamp, 15.1% of the light is lost, so that the brightness of the direct type liquid crystal display device is lowered. have.

An object of the present invention is to conceive in view of the above problems, by preventing a part of the light emitted from the lamp to be re-injected into its own lamp or to be lost to the other lamp adjacent to it, the direct-type liquid crystal display device It is to raise the brightness of.

Other objects of the present invention will become more apparent from the following detailed description and the accompanying drawings.

1 is an explanatory diagram for explaining that light is lost in a liquid crystal display of a direct type method in which a conventional reflector is applied.

Figure 2 is a partially cut perspective view showing the structure of a direct type liquid crystal display device according to the present invention.

Figure 3 is an exploded perspective view showing the structure of the reflector and the lamp unit according to the present invention.

4 is an explanatory view for explaining that light is reflected toward a diffuser plate by a reflector in a liquid crystal display device of a direct type to which a reflector according to the present invention is applied.

In order to achieve the above object, the present invention is formed by projecting the light reflecting projections toward the lamp unit to prevent the light emitted from the lamp is re-incident to its lamp in the portion corresponding to the respective lamps of the reflecting plate.

In addition, a predetermined portion between the lamps is formed with light blocking protrusions higher than the lower surface of the lamp to prevent light emitted from each of the lamps from being incident and lost to other lamps adjacent to each other.

Preferably, the light reflecting projections and the light blocking projections are formed in a triangular cross section, the vertices of the light reflecting projections are located at the center of the lamp, and the vertices of the light blocking projections are located at the center at the distance between the lamps.

Hereinafter, the structure of a direct liquid crystal display device according to the present invention will be described with reference to FIGS. 2 to 4.

As shown in FIG. 2, the direct liquid crystal display device 100 according to the present invention is accommodated in a mold frame 110 having a rectangular storage space and a storage space of the mold frame 110 to reflect light upward. The lamp unit 130, which is installed on the upper surface of the reflector plate 120 and the reflector plate 120, emits light and is spaced apart from the lamp unit 130 by a predetermined distance, and is installed on the lamp unit 130. Diffusion plate 150 for uniformly diffusing the light emitted from the), the bottom chassis 160, the diffusion plate 150 is fastened to the lower surface of the mold frame 110 to support the reflector plate 120 and the lamp unit 130 It is composed of a liquid crystal panel 170 that is installed on the upper portion of the display and the top chassis 180 to cover the upper surface of the liquid crystal panel 170 to support the liquid crystal panel 170.

The mold frame 110, the lamp unit 130, the reflecting plate 120, the bottom chassis 160, and the top chassis 180, which require further description of these components, will be described.

First, the mold frame 110 penetrates from an upper surface to a lower surface and is placed on an upper surface of the first mold frame 111 and an upper surface of the first mold frame 111 to face the liquid crystal panel 170. It consists of a second mold frame 115 formed with a storage space on one surface.

The receiving plate 120 and the lamp unit 130 are accommodated in the storage space having a predetermined depth formed on the lower surface side of the storage space of the first mold frame 111, and the storage space formed on the upper surface side of the first mold frame 111. Diffusion plate 150 is installed in the storage space formed on the upper surface side of the first mold frame 111 is larger than the storage space formed on the lower surface side of the first mold frame 111, the storage spaces A step is generated between them.

In addition, the liquid crystal panel 170 is accommodated in the storage space formed on the upper surface of the second mold frame 115, and the base surface of the storage space is larger than the screen display area that is a portion where the screen is displayed on the liquid crystal panel 170. A large open area is formed and light emitted from the diffusion plate 150 is incident on the liquid crystal panel 170.

Next, a description will be given of the configuration of the lamp unit 130, the lamp unit 130 is divided into a plurality is installed on the upper surface of the reflecting plate 120, where a plurality of lamp unit 130 is not integrally formed The reason why it is formed by dividing into is that when an abnormality occurs in any one of the plurality of lamps, the lamp unit 130 in which the abnormally occurring lamp exists is removed to the outside of the liquid crystal display device 100 to easily replace the lamp. To do that.

As described above, the lamp units 130 divided into a plurality of cold electrodes (not shown) are formed at one end with a hot electrode (not shown) to which power is applied, and a current is returned to the other end as shown in FIG. 3. Two lamp holders 134 formed to protect the lamps 132 by forming a plurality of lamps 132, which are formed to emit light, and lamp insertion holes (not shown) formed at the side facing the end of the lamp 132. For example, each lamp 132 is electrically connected to the lamps 132 by lamp supports 136 and 140 and wires 138 and 139 coupled with the respective lamp holders 134 to facilitate replacement of the lamp 132. ) Is made up of a lamp driver (not shown).

Among the members constituting the lamp unit 130, the lamp support 140 fastened to the hot side of the lamp 132 is spaced apart from the cover plate 142 and the cover plate 142, which are coupled to the bottom chassis 160. And a lamp holder inserting portion 144 which is formed in the lamp holder 134 and surrounds both sides in the longitudinal direction from the upper surface of the lamp 132, and is formed between the cover plate 142 and the lamp holder inserting portion 144. A gap 146 having a size is formed so that the wire 138 connected to the hot electrode exits to the outside of the bottom chassis 160 through this portion.

On the other hand, the reflector 120 according to the present invention is installed on the lower surface of the lamp unit 130 is coupled to the lamp holder 134, the lamp 132 of the reflector 120 as shown in Figs. ), A light reflection protrusion 122 having a predetermined inclination protrudes toward the lamp unit 130, and light blocking protrusions 122 and 126 having a predetermined inclination also in a predetermined portion between the lamps 132. ) Is projected toward the lamp unit 130 to reflect the light emitted from the lamp 132 toward the diffuser plate 150. Thus, some of the light emitted from the lamp 132 is prevented from re-incident into its lamp 132 or incident to another lamp 132 adjacent thereto.

In more detail with respect to the reflecting plate 120, the light blocking projection 122 formed in the portion corresponding to the lamps 132 of the reflecting plate 120 is the light emitted from the lamp 132 by the reflecting plate 120 In order to prevent reentry into the lamp 132 of its own, the light reflecting protrusion 122 is formed in an area equal to the diameter of the lamp 132 or an area slightly smaller than the diameter of the lamp 132. Preferably, as shown in FIG. 4, the cross section of the light reflection protrusion 122 is triangular in shape, and a vertex is formed at a portion corresponding to the center of the lamp 132, and an angle of the vertex is 15 °.

In addition, the light blocking protrusion 126 formed in a predetermined portion between the lamps 132 of the reflecting plate 120 reflects the light emitted from the lamp 132 toward the diffuser plate 150 and is emitted from the lamp 132. Light is incident on the other lamps 132 adjacent to each other and is lost. The cross section is formed in a triangular shape with the same slope as the light reflection protrusion 122. Preferably, the vertices of the light blocking protrusions 126 are formed at the midpoint (l / 2) of the distance (l) between the lamps 132, and the vertices are formed on the lower surface of the lamp 132 facing the reflector plate 120. Rather, it is slightly higher and lower than the top surface of the lamp 132 facing the diffuser plate 150.

In view of the light utilization efficiency of the lamp 132, the height of the vertex of the most preferable light blocking protrusion 126 should be higher than the center of the lamp 132 and slightly lower than the top surface of the lamp 132 as shown in FIG. 4.

In addition, in view of the uniformity of light, the vertex of the light blocking protrusion 126 is higher than the lower surface of the lamp 132 and the center of the lamp 132 so that the lamp 132 does not stand out when viewed from the screen of the liquid crystal display 100. Lower is most preferred.

Here, since the light blocking protrusion 126 has the same slope as the light reflecting protrusion 122 and is formed over a larger area than the light reflecting protrusion 122, the light blocking protrusion 126 is larger than the light reflecting protrusion 122. Big and high.

In addition, the light reflecting protrusions 122 and the light blocking protrusions 126 of the reflecting plate 120 are formed flat, and the distance of the flat portion 124 is formed from the point where the light reflecting protrusion 122 starts. It is equal to the distance to the vertex of the light reflection protrusion 122.

As described above, when the light reflecting protrusion 122, the flat portion 124, and the light blocking protrusions 126 are continuously formed on the reflecting plate 120, the lower part of the lamp holder 134 coupled with the reflecting plate 120. As shown in FIG. 3, the shaving should have a shape corresponding to that of the reflecting plate 120.

As shown in FIG. 1, the bottom chassis 160 has a quadrangular shape corresponding to the liquid crystal panel 170, and an accommodation space having a predetermined depth is formed from an upper surface to a lower surface to accommodate the first mold frame 111. On one side and the other side in the width direction of the bottom chassis 160 facing the lamp support 140 of the lamp unit 130, the lamp unit 130 is assembled in a sliding manner and predetermined to be pulled out of the bottom chassis 160. A slide slit (not shown) having a size is formed. When the lamp unit 130 is fitted into the storage space of the first mold frame 111, as shown in FIG. 2, the slide slit is formed by the cover plate of the lamp support 140 ( 142).

Lastly, the top chassis 180 has a quadrangular shape corresponding to the liquid crystal panel 170, and an open area for exposing the screen display area of the liquid crystal panel 170 to the outside on an upper surface facing the liquid crystal panel 170. 182 is formed.

The operation of the liquid crystal display device of the direct type according to the present invention configured as described above will be described with reference to FIGS.

When the lamp driver supplies power to each of the lamps 132, that is, the lamps L1 and L2, the lamps L1 and L2 are turned on to emit light in all directions.

Then, the light of the area A in which the light emitted from the lamp L1 of FIG. 1 is directly incident on the lamp L2, and the light of the B area where the light emitted from the lamp L1 is reflected by the conventional reflector and is incident on the lamp L3 is provided. Since the light hits the light blocking protrusion 126 formed between the lamps and is reflected at an angle such that it is not incident to the other lamps 132 adjacent to each other, the light emitted from the lamp L1 cannot enter the lamp L2 and the lamp L3. .

In addition, when the light emitted from the lamp L1 of FIG. 1 is incident on the lamp L2 by the conventional reflector, the light hits the portion 124 formed flat with the light blocking protrusion 126. Reflected at an angle not to be incident to the diffuser 150 is transmitted toward the diffusion plate 150.

Finally, in the present invention, the light of the area D where the light emitted from the lamp L1 of FIG. 1 is re-entered into its lamp L1 by the conventional reflector is diffused by the light reflection protrusions 122 formed in the respective lamps and the lower part. Reflected toward the plate 150. However, some of the light emitted near the vertex of the light reflection protrusion 122 is reflected by the light reflection protrusion 122 and is incident again to the lamp L1, and the angle of reincident to the lamp L1 is 4.14 °.

When the reflecting plate 120 according to the present invention is applied to the direct type liquid crystal display device 100, the light emitted from the lamp 132 is incident on the lamp 132 and the amount of light lost is expressed by Equation 2 below. Obtained through:

<Equation 2>

(4.14 ÷ 360 °) × 100 ≒ 1.15%

That is, since the light emitted from each lamp 132 is reflected toward the diffuser plate 150 by the light reflection protrusion 122 and the light blocking protrusion 126, the other lamps 132 or their lamps 132 adjacent to each other are adjacent to each other. The amount of light lost due to incident light is 1.15%.

As described above, the present invention forms a light reflecting projection to prevent light emitted from the lamp from re-incident to its own lamp in a portion corresponding to the lamps of the reflecting plate, and between the lamps By minimizing light loss by forming a light blocking protrusion for preventing light from being incident on another lamp adjacent to the other lamp, the brightness of the light of the direct type liquid crystal display device can be increased.

Claims (7)

A mold frame in which a storage space is formed; The lamps are spaced apart from the base surface of the storage space by a plurality of lamps installed along a longitudinal direction of the storage space to emit light, and lamp holders and wires fitted to both ends of the lamps to protect the lamps. A lamp unit electrically connected to the lamp unit, the lamp unit including a lamp driver to supply power to the lamps; Installed between the base surface of the storage space and the lamp unit reflects the light emitted from the lamps in the upper direction of the mold frame, and the light emitted from the lamp in the portion corresponding to each of the lamps A reflecting plate for protruding light reflection protrusions toward the lamp to prevent the light from being re-entered into the lamp and being lost; A diffusion plate spaced apart from the lamps by a predetermined distance and installed on the lamps to uniformly diffuse the light emitted from the lamps; And And a liquid crystal display (LCD) panel installed on the diffusion plate to display information. The liquid crystal display of claim 1, wherein the light reflecting protrusions are formed to have a predetermined inclination and have a triangular cross section, and vertices of the light reflecting protrusions are formed at a portion corresponding to the center of the lamps. Device. The liquid crystal display of claim 2, wherein the vertex angle of the light reflection protrusion is 15 degrees. A mold frame in which a storage space is formed; A reflection plate installed on a bottom surface of the storage space to reflect light upward; A plurality of lamps disposed in the longitudinal direction of the storage space and spaced apart from the reflecting plate to emit light, and are electrically connected to the lamps by lamp holders and wires fitted to both ends of the lamps to protect the lamps. A lamp unit including a lamp driver configured to supply power to the lamps; A diffusion plate spaced apart from the lamps by a predetermined distance and installed on the lamps to uniformly diffuse the light emitted from the lamps; And An LCD panel installed on the diffusion plate to display information; The reflector plate Light reflection protrusions protruding toward the lamp in a portion corresponding to each of the lamps to prevent the light emitted from the lamp from being re-entered into its lamp and lost; A direct blocking method, wherein light blocking protrusions are formed on a predetermined portion between the lamps to prevent the light emitted from the lamps from entering and being lost to other lamps adjacent to each other; LCD display device. The liquid crystal display of claim 4, wherein the light reflection protrusions and the light blocking protrusions have a triangular cross section, and the vertices of the light blocking protrusions are formed in the center between the lamps. The LCD of claim 4, wherein a predetermined portion of the reflective plate between the light reflection protrusions and the light blocking protrusions is formed flat. 7. The liquid crystal display device according to claim 6, wherein a length of the flatly-formed portion is equal to a length from a portion at which the light reflection protrusion starts to a vertex of the light reflection protrusion.