KR20050010482A - Surface light source, method of manufacturing the same and liquid crystal display apparatus having the same - Google Patents

Abstract

PURPOSE: A surface light source device is provided to compensate stress generated on a lower substrate while forming barrier walls on the lower substrate by that generated on the lower substrate while forming a reflection layer thereon, thereby preventing the deformation of the lower substrate formed with the barriers and the reflection layer. CONSTITUTION: A surface light source device includes an upper substrate(3), and a lower substrate(5) corresponding to the upper substrate. A plurality of barrier walls(10) are formed between the upper and lower substrates for forming discharging spaces(11) between the upper and lower substrates. The lower substrate is formed with a reflecting layer(15), and insides of the discharging spaces are respectively formed with fluorescent layers(20). As predetermined electric fields are applied into the discharging spaces from electrodes, plasma discharge is induced into the discharge spaces, generating UV rays. By the UV rays, fluorescent substances is excited from the fluorescent layer, and visible rays are generated from the fluorescent layer. The electrodes surrounds both outer surfaces of the upper or lower substrate.

Description

A surface light source device, a method of manufacturing the same, and a liquid crystal display including the same {SURFACE LIGHT SOURCE, METHOD OF MANUFACTURING THE SAME AND LIQUID CRYSTAL DISPLAY APPARATUS HAVING THE SAME}

The present invention relates to a surface light source device, a method for manufacturing the same, and a liquid crystal display device including the same. More particularly, the present invention relates to a surface light source device, a method for manufacturing the same, and a liquid crystal display device including the same. will be.

In general, a liquid crystal display apparatus (LCD) displays an image by using electrical and optical characteristics of a liquid crystal. The liquid crystal display device has an advantage of a very small volume and light weight compared to the CRT, etc. As a result, it is widely used in portable computers, communication devices and liquid crystal TVs.

In order to control the liquid crystal, the liquid crystal display device requires a liquid crystal control part for controlling the liquid crystal and a light supply part for supplying light to the liquid crystal.

The light supply part of the conventional liquid crystal display device is mainly used a cold cathode fluorescent lamp (CCFL) having a rod shape or a light emitting diode (LED) having a dot shape. Cold cathode ray tube type lamp has a high brightness, long life, and has the advantage of having a very low heat generation compared to incandescent lamps. The light emitting diode has advantages of low power consumption and high brightness. However, the conventional cold cathode ray tube lamps or light emitting diodes have a disadvantage in that the luminance uniformity is weak.

In order to solve this problem, a surface light source device in the form of a flat plate is proposed. However, the conventional surface light source device has a problem that deformation of components occurs in the manufacturing process, the deformation can be further deepened in the large sized surface light source device.

Accordingly, an object of the present invention is to provide a surface light source device including components such as an upper substrate and a lower substrate, which are prevented from deformation even in a large size.

Another object of the present invention is to provide a method of manufacturing a surface light source device capable of preventing deformation of components such as an upper substrate and a lower substrate even when having a large size.

Still another object of the present invention is to provide a liquid crystal display device using a surface light source device including components such as an upper substrate and a lower substrate, which are prevented from deformation even in a large size, as a light source.

1 is a partial cutaway perspective view of a surface light source device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the surface light source device shown in FIG. 1 taken along the line II-II '.

3 is a cross-sectional view of the surface light source device shown in FIG. 1 taken along line III-III '.

4 and 5 are cross-sectional views illustrating a method of manufacturing a surface light source device according to an embodiment of the present invention.

6 is a flowchart illustrating a method of manufacturing a surface light source device according to an embodiment of the present invention.

7 is an exploded perspective view illustrating a liquid crystal display device having the surface light source device of FIG. 1.

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

1: surface light source device 3: upper substrate

5: lower substrate 10: partition wall

11: discharge space 15: reflective layer

20: fluorescent layer 25: sealing member

30 electrode 70 display unit

80: storage container 100: liquid crystal display device

In order to achieve the above object of the present invention, the present invention provides a plurality of discharge spaces formed between an upper substrate, a lower substrate corresponding to the upper substrate, and the upper substrate and the lower substrate to form discharge spaces between the upper and lower substrates. It provides a surface light source device including two partitions, a reflective layer formed on the lower substrate and a fluorescent layer formed in the discharge space.

The surface light source device may further include a voltage applying unit for applying a voltage to the discharge space. The voltage applying unit includes a plurality of electrodes surrounding outer surfaces of at least one of the upper and lower substrates in a direction substantially orthogonal to the longitudinal direction of the partition wall.

The barrier ribs generate a first stress on the lower substrate in a first direction, and the reflective layer generates a second stress on the lower substrate in a second direction. Since the first direction is opposite to the second direction, the first stress of the lower substrate is compensated by the second stress of the lower substrate. The first stress is generated by a difference between a thermal expansion coefficient of the lower substrate and a thermal expansion coefficient of the partition walls, and the second stress is generated by a difference between a thermal expansion coefficient of the lower substrate and a thermal expansion coefficient of the reflective layer. Preferably, the difference between the thermal expansion coefficient of the lower substrate and the thermal expansion coefficient of the partition walls is substantially the same as the difference between the thermal expansion coefficient of the lower substrate and the thermal expansion coefficient of the reflective layer. That is, the thermal expansion coefficient of any one of the partitions and the reflective layer is about 80 to about 100% of the thermal expansion coefficient of the lower substrate, and the thermal expansion coefficient of the other of the partitions and the reflective layer is the thermal expansion coefficient of the lower substrate. About 100 to about 120%.

The present invention provides a method of manufacturing a surface light source device for realizing another object of the present invention. First, a plurality of partitions are formed on a lower substrate. The barrier ribs generate a first stress on the lower substrate in a first direction. Next, a reflective layer is formed on the lower substrate. The reflective layer generates a second stress on the lower substrate in a second direction. Next, after forming a fluorescent layer on the reflective layer and the upper substrate, the upper substrate and the lower substrate is sealed to form discharge spaces between the upper substrate and the lower substrate.

The method of manufacturing the surface light source device may further include forming a voltage applying unit for applying a voltage to the discharge space. The voltage applying unit includes a plurality of electrodes surrounding outer surfaces of at least one of the upper and lower substrates in a direction substantially orthogonal to the longitudinal direction of the partition wall.

According to another aspect of the present invention, there is provided an upper substrate, a lower substrate corresponding to the upper substrate, a plurality of partition walls formed between the upper substrate and the lower substrate to form discharge spaces, and on the lower substrate. A surface light source device including a reflection layer formed on the surface and a fluorescent layer formed in the discharge space, a liquid crystal display panel displaying an image using light emitted from the surface light source device, and the surface light source device and the liquid crystal display panel Provided is a liquid crystal display including a storage container. The barrier ribs generate a first stress on the lower substrate in a first direction, and the reflective layer generates a second stress on the lower substrate in a second direction.

According to the present invention, the stress generated on the lower substrate having the partitions during the formation of the partition walls is compensated by the stress generated on the partition substrates and the lower substrate having the reflective layer while forming the reflective layer. Therefore, deformation generated in the lower substrate including the partition walls may be prevented by a difference in thermal expansion coefficients of the lower substrate, the partition walls and the reflective layer, which are precisely adjusted. In addition, since the upper substrate is formed on the lower substrate having a flat structure, the upper substrate may have a flat structure without deformation. Moreover, even when the surface light source device is enlarged, it is possible to prevent deformation of components such as the lower substrate, the upper substrate, the partition walls, and the reflective layer that the surface light source device includes due to the precisely adjusted thermal expansion coefficient difference. Can be.

Hereinafter, a surface light source device and a method of manufacturing the same according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited to the following embodiments.

The surface light source device includes an upper and lower substrate made of glass, a plurality of partitions for forming discharge spaces between the upper and lower substrates, a reflective layer formed on the lower substrate, a fluorescent layer formed in the discharge spaces, and the discharge. It includes electrodes that generate visible light by inducing plasma discharge in the spaces to excite the fluorescent layer.

Since the surface light source device undergoes a high temperature baking process to form the partitions and the reflective layer on the upper substrate or the lower substrate, the coefficient of thermal expansion of each component must be taken into account to prevent deformation of the upper and lower substrates. That is, the thermal expansion coefficients of the partitions and the reflective layer should be kept as close as possible to the thermal expansion coefficients of the upper and lower substrates.

However, it is difficult to keep the thermal expansion coefficients of the elements formed on the upper or lower substrate and the thermal expansion coefficients of the upper and lower substrates substantially the same as those of the partition walls or the reflective layer. If the thermal expansion coefficients of the elements formed on the upper or lower substrate and the thermal expansion coefficients of the upper and lower substrates are not kept substantially the same, a large deformation may be caused in the upper and lower substrates. The deformation of the upper and lower substrates can be further deepened by the difference in the coefficient of thermal expansion of each component as the surface light source device becomes larger.

1 is a partial cutaway perspective view of a surface light source device according to an embodiment of the present invention, Figure 2 is a cross-sectional view taken along the line II-II 'of the surface light source device shown in Figure 1, Figure 3 is shown in Figure 1 One surface light source device is sectional drawing cut along the III-III 'line | wire.

1 to 3, the surface light source device 1 according to the present embodiment includes an upper substrate 3, a lower substrate 5, a plurality of partitions 10, a reflective layer 15, and a fluorescent layer 20. ), A sealing member 25 and a plurality of electrodes 30.

The upper substrate 3 is made of a transparent material, for example glass, and the lower substrate 5 is arranged to correspond to the upper substrate 3 at predetermined intervals.

The plurality of partitions 10 are disposed at equal intervals between the upper substrate 3 and the lower substrate 5, and as the partitions 10 are formed, between the upper substrate 3 and the lower substrate 5. A plurality of discharge spaces 11 are provided in the.

The reflective layer 15 is formed on the lower substrate 5.

The fluorescent layer 20 includes a first fluorescent layer 20a and a second fluorescent layer 20b. The first fluorescent layer 20a is formed on the reflective layer 15, and the second fluorescent layer 20b is formed on the upper substrate 3. The partitions 10, the reflective layer 15, and the fluorescent layer 20 are formed through a high temperature baking process.

The plurality of electrodes 30 surrounds both outer surfaces of at least one of the upper and lower substrates 3 and 5 in a direction substantially perpendicular to the longitudinal direction of the partition 10. The electrodes 30 generate an electric field inducing the plasma discharge in the discharge spaces 11 to excite the fluorescent material of the fluorescent layer 20, thereby generating light from the fluorescent material of the fluorescent layer 20.

In this embodiment, one of the thermal expansion coefficients of the partitions 10 and the reflective layer 15 is smaller than the thermal expansion coefficient of the lower substrate 5, and the other is larger than the thermal expansion coefficient of the lower substrate 5. For example, when the thermal expansion coefficient of the partitions 10 is smaller than the thermal expansion coefficient of the lower substrate 5, the thermal expansion coefficient of the reflective layer 15 is larger than the thermal expansion coefficient of the lower substrate 5. On the contrary, when the thermal expansion coefficient of the partitions 10 is larger than the thermal expansion coefficient of the lower substrate 5, the thermal expansion coefficient of the reflective layer 15 is smaller than the thermal expansion coefficient of the lower substrate 5. Here, the absolute value of the difference between the thermal expansion coefficients of the partitions 10 and the reflective layer 15 with respect to the thermal expansion coefficient of the lower substrate 5 is substantially the same.

The coefficient of thermal expansion of the partitions 10 and the reflective layer 15 is preferably about 80 to about 120% of the coefficient of thermal expansion of the lower substrate 5. More specifically, the coefficient of thermal expansion of any one of the partitions 10 and the reflective layer 15 is about 80 to about 100% of the coefficient of thermal expansion of the lower substrate 5, and the other coefficient of thermal expansion is lower substrate 5. About 100 to about 120% of the coefficient of thermal expansion of For example, when the coefficient of thermal expansion of the partitions 10 is about 80 to about 100% of the coefficient of thermal expansion of the lower substrate 5, the coefficient of thermal expansion of the reflective layer 15 is about the coefficient of thermal expansion of the lower substrate 5. On the other hand, when the thermal expansion coefficient of the partitions 10 is about 100 to about 120% of the thermal expansion coefficient of the lower substrate 5, the thermal expansion coefficient of the reflective layer 15 is lower substrate. It becomes about 80 to about 100% of the thermal expansion coefficient of (5).

In the present invention, due to the difference in the coefficient of thermal expansion of the lower substrate 5, the partitions 10 and the reflective layer 15, the surface light source device 1 generated in the process of manufacturing the surface light source device 1 The stress may be minimized to prevent deformation of the lower substrate 5. For example, when the thermal expansion coefficient of the partitions 10 is larger than the thermal expansion coefficient of the lower substrate 5 and the thermal expansion coefficient of the reflective layer 15 is smaller than the thermal expansion coefficient of the lower substrate 5, the lower substrate 5 When the partitions 10 are formed on the first substrate, the first stress is generated in the first direction on the lower substrate 5 including the partitions 10 so that the lower substrate 5 is positioned in the partitions 10. Bent to Subsequently, when the reflective layer 15 is formed on the lower substrate 5, a second stress is generated on the lower substrate 5 including the reflective layer 15 in a second direction opposite to the first direction so that the reflective layer 15 is formed. The lower substrate 5 including the 15 is bent in a direction opposite to the direction in which the reflective layer 15 is located. That is, the first stress generated during the process of forming the partitions 10 on the lower substrate 5 is compensated by the second stress generated in the process of forming the reflective layer 15. In contrast, when the thermal expansion coefficient of the partitions 10 is smaller than the thermal expansion coefficient of the lower substrate 5, and the thermal expansion coefficient of the reflective layer 15 is larger than the thermal expansion coefficient of the lower substrate 5, the upper substrate 5 is disposed on the lower substrate 5. When the partitions 10 are formed in the first substrate, the first stress is generated in the first direction on the lower substrate 5 including the partitions 10 so that the lower substrate 5 may be aligned with the direction in which the partitions 10 are positioned. Bent in the opposite direction. Subsequently, when the reflective layer 15 is formed on the lower substrate 5, a second stress is generated on the lower substrate 5 including the reflective layer 15 in a second direction opposite to the first direction so that the reflective layer 15 is formed. The lower substrate 5 including the 15 is bent in the direction in which the reflective layer 15 is located. Similarly, the first stress generated during the process of forming the partitions 10 on the lower substrate 5 is compensated by the second stress generated in the process of forming the reflective layer 15. Accordingly, deformation of the lower substrate 5 including the partitions 10 and the reflective layer 15 is prevented.

The upper substrate 3 has a square plate shape. The lower substrate 5 may comprise a transparent material such as glass, and has a square plate shape like the upper substrate 3. The upper substrate 3 and the lower substrate 5 have substantially the same size and are made of the same material. The thermal expansion coefficients of the upper substrate 3 and the lower substrate 5 are about 0.0000050 to about 0.0000150 / ° C, respectively. The upper substrate 3 and the lower substrate 5 are made of, for example, soda lime glass.

The sealing member 25 is disposed between the periphery of the upper substrate 3 and the periphery of the lower substrate 5 to seal the discharge spaces 11 between the upper substrate 3 and the lower substrate 5. The sealing member 25 has the shape of the rectangular frame of the same size as the upper board | substrate 3 and the lower board | substrate 5, for example.

The partitions 10 are disposed on the lower substrate 5 at equal intervals from each other. The partitions 10 are formed using a material having a viscosity such as mud or ceramic. After placing the viscous material on the lower substrate 5 in a predetermined shape, the lower substrate 5 having the viscous material formed thereon is sintered at a high temperature to form partition walls on the lower substrate 5. 10) is formed. Hereinafter, the firing process for forming the partitions 10 on the lower substrate 5 is referred to as a "barrier firing process".

The partitions 10 are arranged parallel to each other. In this embodiment, each of the partitions 10 is not in contact with the sealing member 25 disposed between the upper substrate 3 and the lower substrate 5, so that the discharge spaces defined by the partitions 10 are limited. Allow (11) to partially communicate with each other.

In the barrier rib baking process, the viscous material is disposed on the lower substrate 5, and the lower substrate 5 including the viscous material is heated to a high temperature. Here, the partition walls 10 are firmly attached onto the lower substrate 5 as the liquid viscous component evaporates from the viscous material at high temperature.

When the lower substrate 5 having the partitions 10 formed thereon is cooled at room temperature, the partitions 10 and the lower substrate 5 have different coefficients of thermal expansion, and thus, the lower substrate 5 including the partitions 10 may be attached to the lower substrate 5. The first stress is generated in the first direction so that the lower substrate 5 having the partitions 10 is bent in the direction in which the partitions 10 are located or vice versa. If the thermal expansion coefficient of the partitions 10 is greater than the thermal expansion coefficient of the lower substrate 5, when the lower substrate 5 including the partitions 10 is cooled at room temperature, the shrinkage of the partitions 10 may be reduced. Since it is larger than the shrinkage of 5), the lower substrate 5 on which the partitions 10 are formed is warped in a concave shape as a whole. In contrast, when the coefficient of thermal expansion of the barrier ribs 10 is smaller than the coefficient of thermal expansion of the lower substrate 5, when the lower substrate 5 including the barrier ribs 10 is cooled at room temperature, the shrinkage of the barrier ribs 10 is reduced. Since the lower substrate 5 is smaller than the shrinkage of the lower substrate 5, the lower substrate 5 on which the partitions 10 are formed is curved in a convex shape as a whole.

The reflective layer 15 is formed on the lower substrate 5 by applying a reflector on the lower substrate 5 on which the partitions 10 are formed and then performing a baking process at a high temperature. Hereinafter, the baking process for forming the reflective layer 15 is called "reflection layer baking process".

The reflective layer 15 reflects the light directed toward the lower substrate 5 toward the upper substrate 3 so as to minimize the light generated from the fluorescent layer 20 through the lower substrate 5.

In the reflective layer firing process, a liquid reflector is applied onto the lower substrate 5 on which the partitions 10 are formed, and then the lower substrate 5 on which the reflector is formed is heated at a high temperature. When the liquid material in the reflector evaporates at a high temperature, the reflective layer 15 is formed on the lower substrate 5. When the lower substrate 5 on which the reflective layer 15 is formed is cooled at room temperature, the lower substrate 5 may be positioned in the direction in which the reflective layer 15 is located or in accordance with the difference in the thermal expansion coefficients of the reflective layer 15 and the lower substrate 5. Bent in the opposite direction. Since the reflective layer 15 is formed on the lower substrate 5 that is already concave or convex, the curved lower substrate 5 may be formed again into a flat shape. As described above, the partitions 10 are first formed on the lower substrate 5, and then the reflective layer 15 is formed on the lower substrate 5, but the reflective layer 15 is first formed on the lower substrate 5. After the formation, the partitions 10 may be formed on the lower substrate 5.

The fluorescent layer 20 is formed on the upper substrate 3 and the reflective layer 15 between the discharge spaces 11 between the partition walls 10. The fluorescent layer 20 generates visible light by an electric field applied from the electrodes 30 provided on the outside of the upper substrate 3 and the lower substrate 5.

The electrodes 30 receive an electric current from the outside to generate an electric field that induces plasma discharge in the discharge spaces 11, and the ultraviolet light generated by the plasma discharge generates a fluorescent material of the fluorescent layer 20. By excitation, the fluorescent layer 20 generates visible light.

Hereinafter, the manufacturing method of the surface light source device which has the above-mentioned structure is demonstrated with reference to FIGS.

4 and 5 are cross-sectional views illustrating a method of manufacturing a surface light source device according to an embodiment of the present invention, and FIG. 6 is a flowchart illustrating a method of manufacturing a surface light source device according to an embodiment of the present invention. .

In the present embodiment, the thermal expansion coefficient of the lower substrate 5 is about 0.0000085 / ° C, the thermal expansion coefficient of the partitions 10 is about 0.0000090 / ° C, and the thermal expansion coefficient of the reflective layer 15 is about 0.0000078 / ° C. It is enough. In this case, the length of the lower substrate 5 is about 700 mm.

4 to 6, a plurality of partitions 10 are disposed on the lower substrate 5 to form discharge spaces 11 between the upper substrate 3 and the lower substrate 5. (S1). Subsequently, a plurality of barrier ribs 10 are formed on the lower substrate 5 through the barrier rib firing process (S3). Here, since the coefficient of thermal expansion of the barrier ribs 10 is larger than that of the lower substrate 5, the lower substrate 5 is disposed in the direction in which the barrier ribs 10 are located due to the first stress generated in the first direction. Bent concavely in a direction parallel to one another. That is, the lower substrate 5 on which the partitions 10 are formed is bent upwards.

After applying the reflector on the lower substrate 5 (S5), the reflective layer 15 is formed on the lower substrate 5 having the partitions 10 through the reflective layer firing process (S7). Since the thermal expansion coefficient of the reflective layer 15 is smaller than the thermal expansion coefficient of the lower substrate 5, the stress corresponding to the first stress in the first direction is generated in the lower substrate 5 so that the partitions 10 are formed. ) And the lower substrate 5 including the reflective layer 15 are bent convex again. That is, the lower substrate 5 is bent downward. The difference between the thermal expansion coefficient of the partitions 10 and the thermal expansion coefficient of the lower substrate 5 is substantially the same as the difference between the thermal expansion coefficient of the lower substrate 5 and the thermal expansion coefficient of the reflective layer 15. Therefore, the first stress is compensated by the second stress, and thus the lower substrate 5 including the partitions 10 and the reflective layer 15 has an overall flat structure. For example, the lower substrate 5 that is concavely curved by the barrier rib predetermined process is formed almost flat through the reflective layer firing process.

Referring to FIG. 6 again, a phosphor is coated on the reflective layer 15 in the discharge spaces 11 between the partitions 10 to form the first phosphor layer 20a (S9).

Next, after the phosphor is coated on the upper substrate 3 to form the second fluorescent layer 20b (S11), the sealing member 25 is disposed between the edges of the upper substrate 3 and the lower substrate 5. By attaching to seal the discharge space (11) (S13).

The above-described method for manufacturing the surface light source device 1 may further include forming a voltage applying unit for applying a voltage to the discharge space. In this case, the forming of the voltage applying unit may include forming the plurality of electrodes 30. That is, the electrodes 30 may be formed to surround outer surfaces of both sides of at least one of the upper and lower substrates 3 and 5 in a direction substantially perpendicular to the longitudinal direction of the partition 10. When a predetermined electric field is applied to the discharge spaces 11 from the electrodes 30, plasma discharge is induced in the discharge spaces 11 to generate ultraviolet rays. As the fluorescent material of the fluorescent layer 20 is excited by such ultraviolet rays, visible light is generated from the fluorescent layer 20.

According to another embodiment of the present invention, the coefficient of thermal expansion of the reflective layer 15 is about 20% greater than the coefficient of thermal expansion of the lower substrate 5, and the coefficient of thermal expansion of the partitions 10 is greater than that of the lower substrate 5. Even if it is about 20% smaller, after the barrier rib firing process and the reflective layer firing process are performed, the lower substrate 5 on which the barrier ribs 10 and the reflective layer 15 are formed has a substantially flat structure.

In this embodiment, the partition wall firing process and the reflective layer firing process are performed as a separate process. Alternatively, the partition wall firing process and the reflective layer firing process may be performed in a single process. In addition, the partition and the reflective layer may be formed in-situ.

Hereinafter, a liquid crystal display including a surface light source device according to embodiments of the present invention will be described with reference to FIG. 7.

7 is an exploded perspective view illustrating a liquid crystal display device having the surface light source device of FIG. 1.

Referring to FIG. 7, the liquid crystal display device 100 includes a surface light source device 1, a display unit 70, and a storage container 80.

The surface light source device 1 includes upper and lower substrates 3 and 5, a plurality of partitions (not shown), a reflective layer (not shown), a fluorescent layer (not shown), a sealing member 25, and a plurality of electrodes ( 30). Since the surface light source device 1 employed in the present embodiment is the same as the surface light source device shown in FIG. 1, duplicated description will be omitted.

The display unit 70 includes a liquid crystal display panel 71 displaying an image, a data printed circuit board 72 providing a driving signal for driving the liquid crystal display panel 71, and a gate printed circuit board 73. . The data and gate printed circuit boards 72 and 73 are electrically connected to the liquid crystal display panel 71 through a tape carrier package (TCP) 74 and a gate TCP 75, respectively.

The liquid crystal display panel 71 is interposed between a thin film transistor (TFT) substrate 71a, a color filter substrate 71b coupled to the TFT substrate 71a, and the two substrates 71a and 71b. It contains the liquid crystal 71c.

The TFT substrate 71a is a transparent glass substrate on which a switching element TFT (not shown) is formed in a matrix form. Data and gate lines are respectively connected to the source and gate terminals of the TFTs, and a pixel electrode (not shown) made of a transparent conductive material is connected to the drain terminal.

In the color filter substrate 71b, red (R), green (G), and blue (B) pixels (not shown), which are color pixels, are formed by a thin film process. A common electrode (not shown) made of a transparent conductive material is formed on the color filter substrate 71b.

The storage container 80 includes a bottom surface 81 and a plurality of side walls 82 formed to form a storage space at an edge portion of the bottom surface 81. The storage container 80 fixes the surface light source device 1 and the liquid crystal display panel 71 so as not to flow.

The bottom surface 81 has a floor area sufficient for the surface light source device 1 to be seated, and preferably has the same shape as the surface light source device 1. In the present embodiment, the bottom surface 81 has a square plate shape similar to the surface light source device 1. The side wall 82 extends perpendicularly from the edge portion of the bottom surface 81 so that the surface light source device 1 does not escape to the outside.

The liquid crystal display 100 according to the exemplary embodiment of the present invention further includes an inverter 60 and a top chassis 90.

The inverter 60 is disposed outside the storage container 80 and generates a discharge voltage for driving the surface light source device 1. The discharge voltage generated from the inverter 60 is applied to the surface light source device 1 through the first and second power supply lines 63 and 64. The first and second power supply lines 63 and 64 are connected to the electrodes 30 formed at both sides of the surface light source device 1, respectively. In this case, the first and second power supply lines 63 and 64 may be directly connected to the electrode 30, or may be connected to the electrode 30 using a separate connection member (not shown).

The top chassis 90 is coupled to the storage container 80 while surrounding the edge portion of the liquid crystal display panel 71. The top chassis 90 prevents the liquid crystal display panel 71 from being damaged by an external impact and prevents the liquid crystal display panel 71 from being separated from the storage container 80.

On the other hand, the liquid crystal display device 100 may further include at least one optical sheet 95 for improving the characteristics of the light emitted from the surface light source device (1). The optical sheet 95 may include a diffusion sheet for diffusing the light or a prism sheet for increasing the luminance of the light.

The liquid crystal display device 100 may further include a mold frame (not shown) disposed between the surface light source device 1 and the optical sheet 95. The mold frame prevents the electrode 30 of the surface light source device 1 from coming into contact with another conductive material. In addition, the mold frame may support the optical sheet 95 to prevent the optical sheet 95 from being separated.

According to the present exemplary embodiment, in the liquid crystal display including the lower substrate, the upper substrate, the partitions, and the reflective layer, deformation of these components can be reduced.

As described above, according to the present invention, the stress generated in the lower substrate during the process of forming the partition walls on the lower substrate is compensated by the stress generated during the formation of the reflective layer on the lower substrate. Accordingly, deformation of the lower substrate on which the partitions and the reflective layer are formed can be prevented. In addition, since the upper substrate is formed on the lower substrate of the flat structure, the upper substrate also has a flat structure without deformation.

Moreover, even when the surface light source device is enlarged, it is possible to prevent deformation of components such as the lower substrate, the upper substrate, the partition walls, and the reflective layer that the surface light source device includes due to the precisely adjusted thermal expansion coefficient difference. Can be.

In addition, in the liquid crystal display including the lower substrate, the upper substrate, the partitions, and the reflective layer, deformation of these components can be reduced.

In the detailed description of the present invention described above with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention. For example, even if another layer is further formed on the lower substrate through a sintering process, the layer further formed on the lower substrate may be formed with the stress generated in the lower substrate during the process of forming the partition and the reflective layer. Compensate for stresses that occur during Accordingly, it is possible to prevent deformation of the lower substrate on which the layer further formed.

Claims (23)

An upper substrate; A lower substrate corresponding to the upper substrate; A plurality of partition walls formed between the upper substrate and the lower substrate to form discharge spaces between the upper and lower substrates, and to generate a first stress in the first direction; A reflective layer formed on the lower substrate and generating a second stress on the lower substrate in a second direction; And Surface light source device including a fluorescent layer formed in the discharge space. The surface light source device of claim 1, wherein the first direction is opposite to the second direction. The surface light source device of claim 2, wherein the first stress of the lower substrate is compensated by the second stress of the lower substrate. The surface light source device of claim 3, wherein the lower substrate has a substantially flat structure. The surface light source device of claim 1, wherein the first stress is generated by a difference between a thermal expansion coefficient of the lower substrate and a thermal expansion coefficient of the partition walls. 6. The surface light source device according to claim 5, wherein the second stress is generated by a difference between a thermal expansion coefficient of the lower substrate and a thermal expansion coefficient of the reflective layer. The surface light source device of claim 6, wherein a difference between a thermal expansion coefficient of the lower substrate and a thermal expansion coefficient of the partition walls is substantially the same as a difference between the thermal expansion coefficient of the lower substrate and the thermal expansion coefficient of the reflective layer. 7. The thermal expansion coefficient of the barrier ribs according to claim 6, wherein the thermal expansion coefficient of the partitions is about 80 to about 100% of the thermal expansion coefficient of the lower substrate, and the thermal expansion coefficient of the reflective layer is about 100 to about 120% of the thermal expansion coefficient of the lower substrate. Surface light source device. 7. The thermal expansion coefficient of the barrier ribs according to claim 6, wherein the thermal expansion coefficient of the barrier ribs is about 100 to about 120% of the thermal expansion coefficient of the lower substrate, and the thermal expansion coefficient of the reflective layer is about 80 to about 100% of the thermal expansion coefficient of the lower substrate. Surface light source device. 7. The surface light source device according to claim 6, wherein the thermal expansion coefficient of the upper substrate and the thermal expansion coefficient of the lower substrate are substantially the same. The surface light source device of claim 1, further comprising a voltage applying unit configured to apply a voltage to the discharge space. The surface light source device of claim 11, wherein the voltage applying unit comprises a plurality of electrodes surrounding outer surfaces of at least one of the upper and lower substrates in a direction substantially orthogonal to a longitudinal direction of the partition wall. Forming a plurality of barrier ribs on the lower substrate to generate a first stress in a first direction on the lower substrate; Forming a reflective layer on the lower substrate, the reflective layer generating a second stress in a second direction on the lower substrate; Forming a fluorescent layer on the reflective layer and the upper substrate; And Sealing the upper substrate and the lower substrate to form discharge spaces between the upper substrate and the lower substrate. The surface light source device of claim 13, wherein the first direction is opposite to the second direction, and the first stress of the lower substrate is compensated by the second stress of the lower substrate. Way. The method of claim 14, wherein the first stress is generated by a difference between a coefficient of thermal expansion of the lower substrate and a coefficient of thermal expansion of the partition walls, and the second stress is determined by a difference between a coefficient of thermal expansion of the lower substrate and a coefficient of thermal expansion of the reflective layer. Generated by the method for producing a surface light source device. The method of claim 15, wherein the difference between the thermal expansion coefficient of the lower substrate and the thermal expansion coefficients of the partition walls is substantially the same as the difference between the thermal expansion coefficient of the lower substrate and the thermal expansion coefficient of the reflective layer. 16. The thermal expansion coefficient of claim 15, wherein the thermal expansion coefficient of any one of the barrier ribs and the reflective layer is about 80 to about 100% of the thermal expansion coefficient of the lower substrate, and the thermal expansion coefficient of the other of the barrier ribs and the reflective layer is the lower substrate. And about 100 to about 120% of the coefficient of thermal expansion of the surface light source device. The method of manufacturing a surface light source device according to claim 13, further comprising forming a voltage applying unit for applying a voltage to the discharge space. The surface light source device of claim 18, wherein the voltage applying unit comprises a plurality of electrodes surrounding an outer surface of at least one of the upper and lower substrates in a direction substantially orthogonal to a longitudinal direction of the partition wall. Manufacturing method. A plurality of partition walls formed between an upper substrate, a lower substrate corresponding to the upper substrate, the upper substrate and the lower substrate to form discharge spaces, and generating a first stress in the first direction in the lower substrate, the lower substrate A surface light source device formed on the lower substrate and including a reflective layer generating a second stress in a second direction on the lower substrate and a fluorescent layer formed inside the discharge space; A liquid crystal display panel which displays an image using light emitted from the surface light source device; And And a storage container accommodating the surface light source device and the liquid crystal display panel. The liquid crystal display of claim 20, wherein the first direction is opposite to the second direction, and the first stress of the lower substrate is compensated by the second stress of the lower substrate. The method of claim 20, wherein the first stress is generated by a difference between a thermal expansion coefficient of the lower substrate and a thermal expansion coefficient of the partition walls, and the second stress is based on a difference between the thermal expansion coefficient of the lower substrate and the thermal expansion coefficient of the reflective layer. A liquid crystal display device characterized by being generated by The surface light source device of claim 20, wherein the surface light source device includes a plurality of electrodes surrounding an outer surface of at least one of the upper and lower substrates in a direction substantially orthogonal to the longitudinal direction of the partition wall to apply voltage to the discharge space. And a voltage applying unit.