KR20080041896A - Backlight assembly - Google Patents

Abstract

A backlight assembly is provided to prevent heat generated in a fluorescent lamp from being transmitted to an LCD panel through a mold frame, thereby preventing a defect caused by the deterioration of the LCD panel by a heat load. A backlight assembly comprises a lamp(165), a mold frame(130), and a lamp holder(161). The lamp emits light. The mold frame is positioned in the upper part of the lamp, and includes a mounting portion(132) and an outer wall portion(131). An LCD(Liquid Crystal Display) panel is mounted on the mounting portion. The outer wall portion forms an outer wall by contacting the mounting portion. An opening portion is formed by opening the outer wall portion positioned in an edge. The lamp is inserted into the lamp holder. The lamp holder is joined to the opening portion. The lamp holder comprises a body portion(168), an insulating board, and an insulating side wall portion(163). The lamp is inserted into the body portion. The insulating board is positioned in the upper part of the body portion. The upper surface of the insulating board forms a plane. The plane contacts the mold frame. The insulating side wall portion contacts the insulating board vertically. The insulating side wall portion is inserted to the opening portion to form the edge of the mold frame.

Description

Backlight assembly

1 is an exploded perspective view of a liquid crystal display according to a first exemplary embodiment of the present invention.

FIG. 2 is a perspective view of the intermediate frame and the lamp assembly included in the liquid crystal display of FIG. 1.

3 is a perspective view of an intermediate frame included in the liquid crystal display of FIG. 1.

4 is an exploded perspective view of a lamp assembly included in the liquid crystal display of FIG. 1.

5A is a diagram illustrating a temperature measurement position of a liquid crystal panel included in the liquid crystal display of FIG. 1.

5B is a graph for explaining a temperature distribution of a liquid crystal panel included in the liquid crystal display of FIG. 1.

6 is a perspective view illustrating a coupling between the intermediate frame and the lamp holder included in the liquid crystal display according to the second exemplary embodiment of the present invention.

7 is a perspective view of the intermediate frame of FIG. 6.

8 is an exploded perspective view of the lamp assembly of FIG. 6.

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

10: liquid crystal display device 100: liquid crystal panel assembly

110: upper storage container 120: backlight assembly

130: middle frame 131: outer wall portion

132: mounting portion 133: support wall

134: corner portion 135: opening

140: optical sheets 150: light guide plate

160: lamp assembly 161: lamp holder

162: heat insulation plate 163: heat insulation side wall

164: lamp insertion groove 165: lamp

166: lamp cover 167: space part

168: body portion 170: reflecting plate

180: lower storage container

The present invention relates to a backlight assembly, and more particularly, to a backlight assembly having a structure for preventing heat generated from a lamp from being transferred to a liquid crystal panel.

Liquid crystal display (LCD) is one of the most widely used flat panel display (FPD), and consists of two substrates on which electrodes are formed and a liquid crystal layer interposed therebetween. A display device adjusts the amount of light transmitted by rearranging liquid crystal molecules of a liquid crystal layer by applying a voltage to an electrode.

Since the liquid crystal display itself is non-luminescent, a separate external light source is required to irradiate light. The external light source is appropriately selected according to the size and purpose of the liquid crystal display. Point light sources such as emitter diodes, line light sources such as Cold Cathode Fluorescent Lamps (CCFL), and surface light sources are classified.

As a lamp used as a line light source, a fluorescent lamp is usually used. According to the arrangement, the fluorescent lamp is positioned directly below the liquid crystal panel to directly transmit light, and the fluorescent lamp is positioned on the side of the light guide plate positioned below the liquid crystal panel to form a surface light source through the light guide plate. There is an edge type for transmitting light to the liquid crystal panel.

In addition to emitting light, the fluorescent lamp generates heat together. In the edge type, the fluorescent lamp directly contacts the intermediate frame, and heat is directly transmitted to the liquid crystal panel by conduction. Particularly, both ends of the fluorescent lamp generate heat at a higher temperature than the center of the liquid crystal panel, so that a high temperature part is generated at the corner of the intermediate frame.

As such, when the edge portion of the intermediate frame becomes high temperature, heat is transferred to the liquid crystal panel accommodated in the intermediate frame, thereby deteriorating performance due to high temperature heat load.

It is an object of the present invention to provide a backlight assembly having a structure for preventing heat generated by a fluorescent lamp from being transferred to a liquid crystal panel through an intermediate frame.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

The backlight assembly according to an embodiment of the present invention for achieving the above technical problem, a lamp for emitting light, a seating portion located on the upper portion of the lamp and the outer wall in contact with the seating portion to form an outer wall And a mold frame in which the outer wall portion located at an edge thereof is opened to form an opening, and a lamp holder into which the lamp is inserted and coupled to the opening.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

The spatially relative terms " below ", " beneath ", " lower ", " above ", " upper " It can be used to easily describe the correlation of an element or components of the element with other elements or components. Spatially relative terms are to be understood as including terms in different directions of the device in use or operation in addition to the directions shown in the figures. Like reference numerals refer to like elements throughout.

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

1 and 2, a backlight assembly according to a first embodiment of the present invention will be described in detail. 1 is an exploded perspective view of a liquid crystal display according to a first exemplary embodiment of the present invention, and FIG. 2 is a combined perspective view of an intermediate frame and a lamp holder included in the liquid crystal display of FIG. 1.

As shown in FIG. 1, the liquid crystal display 10 according to the first exemplary embodiment of the present invention includes an upper storage container 110, a liquid crystal panel assembly 100, and a backlight assembly 120.

The upper accommodating container 110 forms an external appearance of the liquid crystal display 10, and an open window for exposing the liquid crystal panel assembly 100 to the outside is formed at the center thereof, and a bezel region is formed at the edge of the upper surface. It is.

The liquid crystal panel assembly 100 includes a liquid crystal panel 105, a gate tape carrier package 111, a data tape carrier package 112, and a printed circuit board 113.

The liquid crystal panel 105 serves to display an image on a screen by receiving an electrical signal, and the thin film transistor substrate 108 and the color filter substrate 107 are attached to face each other at regular intervals, and between the substrates. The liquid crystal layer is interposed in the formed space.

A plurality of gate lines (not shown) and data lines (not shown) are formed on the thin film transistor substrate 108. The data line transfers a driving signal by the driving chip on the printed circuit board 113, and the gate line transfers a driving signal by the gate line driver formed in the thin film transistor substrate 108.

The backlight assembly 120 includes a lamp assembly 160, an intermediate frame 130, optical sheets 140, a light guide plate 150, a reflector plate 170, and a lower storage container 180.

The lamp assembly 160 serves to supply light for the liquid crystal panel 105 to display an image, and includes a lamp 165, a lamp holder 161, and a lamp cover 166.

First, as the lamp 165 generates light, various types of lamps may be used, but in one embodiment according to the present invention, a fluorescent lamp is used. As a fluorescent lamp, CCFL (Cold Cathode Fluorescent Lamp), EEFL (External Electrode Fluorescent Lamp) may be used. The lamp 165 generates light by a lamp driving voltage applied from an inverter (not shown). At this time, the lamp 165 emits heat together with generating light.

On the other hand, the lamp 165 is located in the side of the light guide plate 150 in the edge type, one or more may be used if necessary. In addition, the lamp 165 is inserted into the lamp holder 161 and the lamp cover 166 and is positioned on the side of the light guide plate 150, and is accommodated in the intermediate frame 130 together with the light guide plate 150.

The lamp holder 161 transmits a driving voltage to the lamp 165, and supports the lamp 165 to fix the lamp holder 165 to the intermediate frame 130, which will be described later.

The intermediate frame 130 accommodates the optical sheets 140, the light guide plate 150, the reflecting plate 170, and the lamp assembly 160, and is seated and fixed to the lower storage container 180. ), The light guide plate 150, and the lamp assembly 160.

The optical sheets 140 serve to diffuse and collect light transmitted from the light guide plate 150. The optical sheets 140 are disposed on the light guide plate 150 and accommodated in the intermediate frame 130. The optical sheets 140 include a first prism sheet, a second prism sheet, a diffusion sheet, and the like.

The first and second prism sheets refract the light passing through the light guide plate 150 to focus light incident at a low angle to the front to improve brightness of the liquid crystal display in the effective viewing angle range. Such a prism sheet may be used by two sheets to refract light in up, down, left, and right directions to maximize the effect. However, when one prism is sufficient, only one first prism may be used.

The diffusion sheet serves to diffuse the light so that the light supplied from the light guide plate 150 has a uniform brightness as a whole. Light transmitted through the light guide plate 150 forms a small bright spot by a scattering pattern (not shown) of the light guide plate 150, and the light of the bright spot is diffused by the diffusion sheet. Therefore, the light passing through the diffusion sheet forms a surface light source having uniform brightness throughout. In addition, one or more diffusion sheets may be used in the form of a thin sheet, and in some cases, may be formed of one thick plate.

The light guide plate 150 serves to uniformly transmit the light emitted from the lamp 165 to the entire surface of the liquid crystal panel 105, and is made of a light transmitting material so that the light can be efficiently guided. As such a material, an acrylic resin such as polymethyl methacrylate (PMMA) and a material having a constant refractive index such as polycarbonate (PC: PolyCarbonate) may be used.

The light incident on one side of the light guide plate 150 has an angle within a critical angle of the light guide plate 150 and enters the light guide plate 150, but when the incident light reaches the upper or lower surface, the light The angle is greater than the critical angle is not emitted to the outside of the light guide plate 150, but is totally reflected on the surface of the light guide plate 150, the light is evenly transmitted throughout the entire light guide plate 150.

On the other hand, a scattering pattern (not shown) is formed on at least one of the upper and lower surfaces of the light guide plate 150 so that the light inside the light guide plate 150 can be emitted upward. For example, the scattering pattern (not shown) formed on the lower surface of the light guide plate 150 is formed to have a different size and density to have a specular reflection characteristic in proportion to the distance from the lamp 165. Therefore, light reflected from the light guide plate 150 is reflected by scattering pantones (not shown) and is emitted to the outside through the top surface of the light guide plate 150.

The reflecting plate 170 reflects the light emitted in the downward direction of the lamp 165 toward the liquid crystal panel 30 to increase the efficiency of the light. The reflector plate 170 is positioned under the lamp 165 and is coated in a color that reflects light well. In some cases, the reflector plate 170 may be used as a thin sheet.

Hereinafter, an intermediate frame according to a first embodiment of the present invention will be described with reference to FIGS. 2 and 3. 3 is a perspective view of an intermediate frame included in the liquid crystal display of FIG. 1.

The intermediate frame 130 has an outer window 131 formed along an edge of a rectangular shape, and an open window is formed at a central portion thereof so that light passing through the light guide plate 150 and the optical sheets 140 can be transmitted. 105 includes a seating portion 132 on which it is seated. As such, the intermediate frame 130 is made of a material such as polycarbonate, and may be molded by a mold.

The outer wall 131 is formed at a constant height along the outer edge of the intermediate frame 130, and a space for accommodating the liquid crystal panel 105 is formed inside the outer wall 131. The outer wall portion 131 has a rectangular shape, and includes four corner portions 134, and the ends of the corner portions 134 may be rounded as necessary. In addition, the edge portion 134 is formed with an opening 135 in which the outer wall portion 131 is partially opened.

The mounting portion 132 is formed inside the outer wall portion 131 with a predetermined width along the outer wall portion 131 and is formed in a plane having a width enough to allow the liquid crystal panel 105 to be seated. 132 vertically contacts the outer wall 131.

The opening 135 is a space surrounded by the support wall 133 and the seating portion 132 formed by opening a portion of the outer wall portion 131, and the opening 135 has a heat insulation sidewall portion of the lamp holder 161 which will be described later. 163 is inserted. The opening 135 is formed along the edge 134 has a slit shape of the cross-section 'b' shape.

Hereinafter, a lamp assembly according to a first embodiment of the present invention will be described with reference to FIGS. 2 and 4. 4 is an exploded perspective view of a lamp assembly included in the liquid crystal display of FIG. 1.

The lamp assembly 160 includes a lamp 165, a lamp holder 161 and a lamp cover 166. The lamp holder 161 supplies a driving voltage to the lamp 165, and supports the lamp 165 to fix the lamp 165 to the intermediate frame 130. The lamp holder 161 includes a lamp insertion groove 164, a body portion 168, a heat insulation plate 162, and a heat insulation side wall portion 163. The lamp holder 161 of the present invention may serve to supply a driving voltage and support the lamp 165 at the same time. The lamp holder 161 may be installed only at one end of the lamp 165. It is preferable to install at both ends of 165).

The lamp holder 161 is formed of a heat insulating material having a lower thermal conductivity than the material of the intermediate frame 130 to prevent the heat of the lamp 165 from being conducted to other parts of the intermediate frame 130, and the like. 164, the body 168, the heat insulation plate 162, and the heat insulation side wall portion 163 may be integrally formed.

In detail, the body 168 is provided with a lamp insertion groove 164 into which one end of the lamp 165 is inserted. The lamp insertion groove 164 may include a contact terminal (not shown) for applying a driving voltage, and the lamp 165 may be turned on by using a driving voltage applied through the contact terminal (not shown).

The heat insulation plate 162 is positioned on the upper portion of the body 168 and has a planar shape to contact the lower surface of the seating portion 132 formed on the intermediate frame 130. Between the body portion 168 and the heat insulating plate 162 is formed a space portion 167 of a predetermined interval to reduce heat conduction. Such a space 167 is formed with a support member (not shown) capable of supporting the heat insulating plate 162 while minimizing heat conduction. In addition, the heat insulating plate 162 is in direct contact with the mounting portion 132, so that heat generated from the lamp 165 is not transmitted to the intermediate frame 130.

The adiabatic side wall portion 163 is inserted into the opening 135 of the intermediate frame 130, and is coupled to the outer wall portion 131 which is partially opened to form the outer wall of the intermediate frame 130. The heat insulating side wall portion 163 and the outer wall portion 131 serve to guide the liquid crystal panel 105 therein. The heat insulation side wall portion 163 is in contact with the body portion 168 and the heat insulating plate 162 perpendicularly, and is formed to extend perpendicular to the heat insulating plate 162.

In addition, the adiabatic side wall portion 163 has a cross-section 'b' shape, is located in the corner portion 134 of the intermediate frame 130, and serves as the outer wall portion 131, the lamp 165 The heat of is prevented from being transferred to the liquid crystal panel 105 through the edge portion 134 of the intermediate frame 130.

On the other hand, the lamp holder 161 is integrally molded with a heat insulating material, so as to increase the heat insulating effect, the heat insulating plate 162 and the heat insulating side wall portion 163 in direct contact with the intermediate frame 130 is a separate shape Formed to maximize insulation effect.

The lamp cover 166 accommodates the lamp 165 to protect the lamp 165, and efficiently transmits the light generated by the lamp 165 to the light guide plate 150. The lamp cover 166 has a cross-sectional shape of a 'c' shape so that one surface is open, and the open portion faces the light guide plate 150. Inside the lamp cover 166, a paint having high reflectance is applied or a reflective sheet is attached to increase the light efficiency.

In addition, the material of the lamp cover 166 is mainly made of a metal material, and protects the lamp 165 from various shocks and vibrations, and heat generated from the lamp 165 is quickly conducted to diffuse the entire lamp cover 166. . Since the heat generated from the lamp 165 increases at both ends of the lamp 165, the heat at both ends of the lamp 165, which is a relatively high temperature part, is quickly transferred to the center of the lamp 165, so that both ends of the lamp 165 are provided. And thermal gradients in the center can be reduced.

5A is a diagram illustrating a temperature measurement position of a liquid crystal panel included in the liquid crystal display of FIG. 1, and FIG. 5B is a graph for explaining a temperature distribution of the liquid crystal panel included in the liquid crystal display of FIG. 1.

In order to compare the temperature distribution of the liquid crystal panel 105 according to the first embodiment of the present invention and the temperature distribution of the conventional liquid crystal panel, five positions of two liquid crystal panels 105 were selected and the temperature was measured.

Specifically, referring to FIG. 5, the temperature measurement positions are set as the upper left (①), upper right (②), middle (③), lower left (④), and lower right (⑤) of the liquid crystal panel 105.

Temperature measurements for each location are shown in Table 1 below.

Measuring position ① ② ③ ④ ⑤ Conventional Color filter substrate 48.1 47.4 31.0 46.4 47.1 Thin film transistor substrate 42.5 42.8 30.5 41.0 41.4 The present invention Color filter substrate 45.5 44.8 30.8 42.4 42.9 Thin film transistor substrate 39.5 40.6 30.4 36.8 39.0

(Unit: ℃)

Referring to FIG. 5B, the temperature distribution of the liquid crystal panel 105 according to the measurement position is shown. The upper (①, ②) and the lower (④, ⑤) of the liquid crystal panel 105 where the lamp 165 is located are located at the center (③). It can be seen that the temperature is higher than 15 ℃ than). Therefore, it is necessary to effectively block the heat of the lamp 165 which is conducted to the upper and lower portions, that is, the corner of the liquid crystal panel 105.

When comparing the measured value of the temperature distribution of the liquid crystal panel of the conventional liquid crystal display device with the measured value of the temperature distribution of the liquid crystal panel of the liquid crystal display device according to the present invention, the lamp holder according to the first embodiment of the present invention In the case of using 161, the temperature of the liquid crystal panel 105 is lower than that of the conventional lamp holder, and in particular, the temperature of the corners of the liquid crystal panel 105 is significantly reduced.

Hereinafter, a backlight assembly according to a second exemplary embodiment of the present invention will be described with reference to FIGS. 6 to 8. 6 is a perspective view illustrating a coupling between the intermediate frame and the lamp holder included in the liquid crystal display according to the second exemplary embodiment. FIG. 7 is a perspective view of the intermediate frame of FIG. 6, and FIG. 8 is a perspective view of the lamp assembly of FIG. 6. Exploded perspective view. For convenience of description, members having the same functions as the members shown in the drawings of the first embodiment are denoted by the same reference numerals, and therefore description thereof is omitted. 6 to 8, the backlight assembly of the present embodiment has a basically identical structure to the backlight assembly of the first embodiment except for the following.

That is, the backlight assembly 120 according to the second embodiment of the present invention removes the seating portion 132 located at the corner of the intermediate frame 130, and the heat insulating plate 162 of the lamp holder 161 formed of the heat insulating material is directly It is formed to contact the liquid crystal panel 105.

In the seating part 132 according to the second embodiment of the present invention, a portion where the edge of the liquid crystal panel 105 is seated is open. That is, a part of the corner portion of the seating portion 132 is opened to insert the lamp holder 161. The intermediate frame 130 maintains the basic skeleton by the outer wall portion 131, the support wall 133, and the connecting portion 231.

Specifically, the seating portion 132 is opened in the shape of the heat insulating plate 162 in the portion where the lamp holder 161 of the corner portion is located, and the opening 135 together with the portion formed by opening the heat insulating side wall portion 163. To form.

The opening 135 allows the heat insulation side wall portion 163 and the heat insulation plate 162 of the lamp holder 161 to be inserted and fixed. When the heat insulation plate 162 is formed thicker than the lamp holder 161 of the first embodiment and is inserted into the opening 135 formed at the corner portion of the seating portion 132, the top surface of the heat insulation plate 162 is formed of the seating portion 132. It is coupled to form a plane coinciding with the upper surface. The insulation plate 162 uses a material having a lower thermal conductivity than the intermediate frame 130. In this way, the temperature of the edge part in which the temperature is measured highest among the liquid crystal panels 105 can be significantly reduced.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

As described above, according to the backlight assembly according to the embodiments of the present invention, the heat generated by the fluorescent lamp is prevented from being transferred to the liquid crystal panel through the intermediate frame, thereby preventing the occurrence of a defect due to deterioration of the liquid crystal panel due to the heat load. You can prevent it.

Claims (5)

Lamps that emit light; A mold frame disposed on an upper portion of the lamp and including a seating portion on which a liquid crystal panel is mounted and an outer wall portion forming an outer wall in contact with the seating portion, wherein the outer wall portion located at a corner thereof is opened to form an opening; And And a lamp holder into which the lamp is inserted and coupled to the opening. The method of claim 1, wherein the lamp holder, A body portion into which the lamp is inserted; A heat insulating plate positioned above the body part and having an upper surface thereof in contact with the mold frame; And And a heat insulating sidewall portion which is in contact with the heat insulating plate and is inserted into the opening to form the corner of the mold frame. The method of claim 2, Backlight assembly to maintain a gap between the body portion and the insulating plate. The method of claim 1, The opening is formed by opening the outer wall portion and the seating portion located in the corner, The lamp holder, A body portion into which the lamp is inserted; A heat insulating plate positioned above the body part and inserted into the opening and having a top surface coinciding with the seating part to form a plane; And And a heat insulating sidewall portion which is in contact with the heat insulating plate and is inserted into the opening to form the corner of the mold frame. The method of claim 4, wherein And the mold frame includes a connection portion connecting the seating portion to the opening region.

Images