KR20080051800A - Surface light source device and liquid crystal display using the same - Google Patents

Abstract

A surface light source device and a liquid crystal display using the same are provided to uniform the brightness of a light source device and reduce furious frame generated by high voltage. A surface light source device includes a light source body(200), a bulkhead, a main electrode(211,212), a sub electrode(221,222), and a protrusion member(235). The light source body has a rear substrate and a front substrate. The bulkhead is formed in the light source body and divides discharging space. The main electrode is formed vertically compared with a length direction of the discharging space at end of the rear substrate and an outline of the front substrate. The sub electrode is formed vertically compared with length direction of the discharging space between the rear substrate and the main electrode. The protrusion member is formed in the rear substrate.

Description

Surface light source device and liquid crystal display using the same

1 is a plan view showing a surface light source device according to the present invention.

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

3 is a perspective view taken along the line A ₁ -A ₂ of FIG. 2.

4 shows an embodiment of a surface light source device according to the present invention.

5 shows a graph of the luminance measurement of FIG. 4.

6A and 6B illustrate the luminance of FIG. 4.

7 illustrates a liquid crystal display according to the present invention.

<Description of Symbols for Major Parts of Drawings>

Light source body: 100,200,300,400 Back substrate: 250,350,450

Front board: 260,360,460 Bulkhead: 240,340,440

Main electrode: 211,212,311,312,411,412 Auxiliary electrode: 221,222,321,322,421,422

Protruding member: 235,335,435a, 435b Discharge space: 230,330,430

Phosphor layer: 365 Reflective layer: 355

Sealant: 252,352

The present invention relates to a surface light source device and a liquid crystal display device using the same, and more particularly, to a surface light source device and a liquid crystal display device using the same to improve luminance uniformity and to prevent degradation of the phosphor.

In general, a flat panel display (FPD) is classified into a light emitting type and a light receiving type. The light emitting type includes a cathode ray tube, an electroluminescent device, a plasma display panel and the like, and the light receiving type includes a liquid crystal display (LCD).

The liquid crystal display displays an image by using the electrical and optical characteristics of the liquid crystal. Liquid crystal displays are widely used in portable computers, communication devices, liquid crystal televisions, and aerospace industries.

The liquid crystal display itself does not have a structure that emits light and thus cannot display an image unless light is irradiated from the outside. Therefore, an image can be displayed only by installing a separate light source.

In general, a liquid crystal display device mainly uses a light emitting diode (LED), which is a one-dimansion light, or a cold cathode fluorescent lamp (CCFL), which is a two-dimension light. . However, since a light emitting diode or a cold cathode ray tube lamp has a low luminance uniformity, it includes an optical member such as a diffusion sheet, a prism sheet, etc., and thus a liquid crystal display using a cold cathode ray tube type lamp or a light emitting diode. The device has increased in volume and weight, and thus, a surface light source device is recently used.

The surface light source device includes a light source body including a back substrate, a front substrate, and a sealing member, a plurality of partitions, and a power applying unit. The sealing member is disposed along the edges of the rear substrate and the front substrate, and the plurality of partitions are disposed in parallel to the inner space separated from the outside by the sealing member. In this case, the plurality of partition walls form a plurality of discharge spaces in an inner space between the rear substrate and the front substrate, and the plurality of discharge spaces are arranged in a meandering structure or a stripe structure.

When the partition wall is formed in a meandering structure, the plurality of discharge spaces are connected in series with each other, and when the discharge gas is uniformly injected into the entire discharge space through the outermost discharge space, and when the partition wall is formed in the stripe structure, part of the partition wall is formed. The groove is formed in the discharge gas is injected into the entire discharge space. As the discharge gas, xenon (Xe), neon (Ne), mercury (Hg), argon (Ar), krypton (Kr) and the like are used.

On the other hand, in the discharge in the surface light source device, the discharge start voltage depends on the distance between the electrodes. Since the discharge start voltage increases as the distance between the electrodes increases, to solve this problem, a main electrode is formed at the end of the front substrate of the light source body of the surface light source device and a pair of sub-electrodes are disposed therebetween. However, this structure can lower the discharge start voltage, but the discharge sustain voltage still depends on the distance between the main electrodes, so that the discharge sustain voltage cannot be lowered. There is a problem of uneven brightness.

Accordingly, the first technical problem to be achieved by the present invention is to provide a surface light source device having a uniform luminance distribution and low power consumption.

Another object of the present invention is to provide a liquid crystal display device using the surface light source device.

The present invention to achieve the first technical problem,

A light source body including a rear substrate and a front substrate spaced apart at predetermined intervals, a partition wall formed in the light source body to partition a discharge space, and the discharge space at an end of an outer circumferential surface of the rear substrate and the front substrate; A main electrode formed in the longitudinal direction and a vertical direction of the main electrode, an auxiliary electrode formed in the longitudinal direction and a vertical direction of the discharge space between the main electrode of the outer peripheral surface of the rear substrate, and an inner circumferential surface of the rear substrate in contact with the discharge space. And a protruding member, wherein the protruding member has a length from an upper edge of the main electrode to an upper edge of an opposite side of the main electrode of the auxiliary electrode adjacent to the main electrode, and the width of the protruding member is the width of the discharge space. Same as the above, wherein the height of the protruding member is formed in the range of 15 to 75% of the height of the discharge space. It provides a surface light source device.

In addition, the protruding member may include a partition wall material, and the partition wall material may be formed of a paste in which a glass powder, a photosensitive resin, and a filler are mixed.

In addition, the shape of the protruding member may be at least one of a circle, an oval, a triangle or a polygon.

The main electrode and the auxiliary electrode may be made of a conductive film.

In addition, the polarity of the main electrode and the auxiliary electrode adjacent to the main electrode may be the same.

In addition, the light source body may further include a reflective film layer formed on the rear substrate.

The protruding member may be disposed at a position including a region corresponding to the main electrode and an auxiliary electrode adjacent to the main electrode.

The present invention to achieve the second technical problem,

A surface light source unit for uniformly emitting light, a liquid crystal display panel displaying an image using light supplied from the surface light source unit, an optical member disposed between the surface light source unit and the liquid crystal display panel, and the surface light source unit and the optical member A light receiving body including an accommodating container for receiving and an inverter installed on a rear surface of the accommodating container and applying a discharge voltage, wherein the surface light source unit includes a rear substrate and a front substrate spaced apart from each other at predetermined intervals, the light source body A partition wall disposed in the interior of the battery cell, a main electrode formed in a longitudinal direction and a vertical direction of the discharge space at end portions of the outer surface of the rear substrate and the front substrate, and a main electrode of the outer surface of the rear substrate; An auxiliary electrode formed in a longitudinal direction perpendicular to the discharge space discharge, and a rear substrate in contact with the discharge space; A protruding member is formed on a surface, and the protruding member has a length from an upper edge of the main electrode to an upper edge of an opposite side of the main electrode of the auxiliary electrode adjacent to the main electrode, and a width of the protruding member is defined by the discharge space. It is the same as the width, the height of the protruding member provides a liquid crystal display, characterized in that formed in the range of 15 to 75% of the height of the discharge space.

In addition, the protruding member may include a partition wall material, and the partition wall material may be formed of a paste in which a glass powder, a photosensitive resin, and a filler are mixed.

In addition, the shape of the protruding member may be at least one of a circle, an oval, a triangle or a polygon.

The main electrode and the auxiliary electrode may be made of a conductive film.

In addition, the polarity of the main electrode and the auxiliary electrode adjacent to the main electrode may be the same.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, but the present invention is not limited thereto.

1 is a plan view of a surface light source device according to the present invention, Figure 2 is a partial cutaway perspective view of the surface light source device according to the present invention.

Referring to FIG. 1, the light source body 100 including a discharge space 130 partitioned into a plurality of partition walls 140 is a plate-shaped substrate, and the main electrodes 111 and 112 and the auxiliary electrodes 121 and 122 are discharge spaces ( A pair of main electrodes 111 and 112 are disposed at both ends in a direction perpendicular to the longitudinal direction of the 130, and a pair of auxiliary electrodes 121 and 122 are disposed at predetermined intervals between the main electrodes.

Each of the discharge spaces 130, the main electrodes 111 and 112, and the auxiliary electrodes 121 and 122 are connected in parallel, and the inside of the discharge space 130 is filled with discharge gas.

On the other hand, the discharge gas may be an inert gas such as xenon (Xe), neon (Ne), argon (Ar) and krypton (Kr) or a mixed gas and mercury (Hg) thereof, the present invention is not limited in this regard. No.

Referring to FIG. 2, the light source body 200 including a plate-shaped front substrate 260 and a rear substrate 250 spaced apart from each other at predetermined intervals in parallel with the front substrate 260 has a discharge space therein. 230, the main electrodes 211 and 212 are disposed at both ends of the light source body 200 at an outer circumferential surface thereof in a direction perpendicular to the longitudinal direction of the discharge space 230, and the auxiliary electrode 220 is disposed on the rear substrate 250. The main electrodes 211 and 212 are spaced apart at predetermined intervals. When the discharge space 230, the main electrodes 211, 212 and the auxiliary electrodes 221, 222 are connected in parallel and a driving voltage is applied, a uniform voltage is applied to each discharge space to emit light. Protruding members 235 are formed on the inner circumferential surface of the rear substrate 250 of the discharge space 230 corresponding to the positions between the main electrodes 211 and 212 and the auxiliary electrodes 221 and 222 adjacent to the main electrodes 211 and 212.

The back substrate 250 and the front substrate 260 are joined by the sealing member 252 and positioned in parallel with each other. The back substrate 250 and the front substrate 260 may be transparent glass substrates having visible resistance to transmit visible light and block ultraviolet rays, and the back substrate 250 may be an opaque glass substrate. .

The protruding member 235 is formed on the inner circumferential surface of the back substrate 250 of the light source body 200, and the length of the protruding member is formed on the upper edge of the main electrodes 211 and 212 extending from the end of the back substrate 250. In this case, the main electrodes 211 and 212 may be formed to have a length up to an upper edge of an opposite side of the main electrode of the auxiliary electrodes 221 and 222 adjacent thereto. This is because the region adjacent to the main electrode has less plasma than other regions, and a dead zone is generated in the region adjacent to the electrode at the time of light emission, thereby forming a protruding member. It serves to compensate for the luminance to minimize the non-uniformity of the luminance,

In addition, the width of the protruding member 235 may be the same as the width of each discharge space 230 partitioned by the partition wall 240. By forming the width of the protruding member 235 to be the same as the width of each discharge space 230 partitioned by the partition wall 240, the luminance in the width direction of the discharge space 230 in the region where the protruding member 235 is formed It is possible to ensure the uniformity of.

In addition, the height of the protruding member may be formed in the range of 15 to 75% of the height of the discharge space. When the height of the protruding member has a value less than 15% of the height of the discharge space, partial darkening occurs due to electrode formation at a portion where the auxiliary electrodes 221 and 222 are formed, thereby obtaining a uniform luminance distribution as a whole. There will be no. When the height of the protruding member exceeds 75% of the height of the discharge space, the amount of plasma reaching the phosphor in the discharge space corresponding to the portion where the protruding member is formed is larger than the discharge space corresponding to the portion where the protruding member is not formed. It is not preferable that the portion where the protruding member is formed is further increased in brightness.

Meanwhile, the material of the protruding member may be the same as that of the partition wall material, and the partition wall material may be formed of a paste in which glass powder, a photosensitive resin, and a filler are mixed. Protruding member according to the present invention is formed by a paste of a mixture of the glass powder, the photosensitive resin and the filler, when produced by the UV mold method, etc., it is possible to easily produce a partition material of various shapes, changing the shape as necessary As a result, compensation of luminance can be realized in the region where the protruding member is formed.

The glass powder for forming the partition wall material is not particularly limited. For example, 10-25 wt% SrO, 25-40 wt% ZnO, 20-40 wt% B ₂ O ₃ , P ₂ O ₅ or V ₂ O ₅ 5-15% by weight and any alkaline earth metal oxide selected from the group consisting of MgO, CaO, BaO, RaO, BeO and mixtures thereof or the group consisting of MgF, CaF, BaF, RaF, BeF, SrF and mixtures thereof Glass powder containing 0.1 to 5% by weight of any one alkaline earth metal fluoride selected from, 20 to 60% by weight of Bi ₂ O ₃ , 15 to 35% by weight of ZnO, 10 to 35% by weight of B ₂ O ₃ , Al _{1 to} 16% by weight of any one selected from the group consisting of O 3, SiO ₂ , ZrO ₂ and mixtures thereof and any alkaline earth metal selected from the group consisting of MgO, CaO, BaO, RaO, BeO, SrO and mixtures thereof Any one alkaline earth metal fluoride selected from the group consisting of oxides or MgF, CaF, BaF, RaF, BeF, SrF and mixtures thereof Glass powder containing 0.1 to 10% by weight of water or 5 to 20% by weight of SiO ₂ , 15 to 30% by weight of Al ₂ O ₃ , 25 to 60% by weight of B ₂ O ₃ , P ₂ O ₅ 3 to 15 Weight%, any alkaline earth metal oxide selected from the group consisting of MgO, CaO, BaO, RaO, BeO, SrO and mixtures thereof or selected from the group consisting of MgF, CaF, BaF, RaF, BeF, SrF and mixtures thereof Any one selected from the group consisting of at least 3-10% by weight of any one alkaline earth metal fluoride and Li ₂ O, Na ₂ O, K ₂ O, Cs ₂ O, Fr ₂ O, Rb ₂ O and mixtures thereof At least any one of alkali metal oxides of LiF, NaF, KF, CsF, FrF, RbF and any one or more of the alkali metal fluorides selected from the group consisting of 0.1-4 wt% Can be.

The shape of the protruding member may be at least one of circular, elliptical, triangular or polygonal. The protruding member is formed to solve the phenomenon that the luminance is lowered due to the lower distribution rate of plasma in the discharge space corresponding to the region where the external electrode extending from the end of the light source body is formed, thereby reducing the volume of the discharge space. It is possible to form various shapes of the protruding member in the range.

When the volume of the discharge space is reduced as described above, light emission is generated in the discharge space in which the protruding members are disposed with the same amount of current, so that the low luminance light emitting region can emit light with high luminance, thereby increasing the luminance uniformity of the surface light source.

Since the main electrodes 211 and 212 and the auxiliary electrodes 221 and 222 supply energy from the outer surface of the light source body 200 into the discharge space 230, it is preferable to form a surface area for supplying sufficient excitation energy, and the width of the electrode. If the width is wider, the edge width of the surface light source is increased and the non-light emitting area is widened.

Therefore, since it is not preferable to make the widths of the main electrodes 211 and 212 and the auxiliary electrodes 221 and 222 wide, the discharge of the surface light source device is started after the width of the main electrode is formed within the range of the edge width of the limited surface light source device. It is preferable to arrange the auxiliary electrode to lower the voltage.

The main electrodes 211 and 212 and the auxiliary electrodes 221 and 222 may have a pair of main electrodes 211 and 212 at the end of the outer circumferential surface of the light source body 200 in a direction perpendicular to the longitudinal direction of the discharge space 230 partitioned by the partition wall 240. The pair of auxiliary electrodes 221 and 222 may be disposed at predetermined intervals between the main electrodes 211a and 212a disposed on the outer circumferential surface of the rear substrate 250. For example, the electrode may be coated and deposited with a conductive material such as copper (Cu), silver (Au), or nickel (Ni), and the present invention is not limited by the material of the electrode.

Meanwhile, the main electrodes 211 and 212 and the auxiliary electrodes 221 and 222 may be made of a conductive film. This forms a conductive film on the surface light source device by coating a metal thin film or metal oxide on the outer peripheral surface of the back substrate or the front substrate. Alternatively, a conductive film may be formed by coating a metal thin film using phosphorous and tin oxides (Indium-Tin Oxide: ITO), a photolithography patterning method using a photosensitive paste, a photoetching method of a Cr / Cu / Cr electrode, or a microelectrode. The inkjet printing method using the conductive ink applied to formation can be applied.

In the surface light source device of the present invention, driving voltages having the same polarity are simultaneously applied to the main electrodes 211 and 212 and the auxiliary electrodes 221 and 222 adjacent to the main electrode.

The main electrode 211a disposed at one end of the rear substrate 250, the auxiliary electrode 221 adjacent to the main electrode 211a, and the main electrode 211b of the front substrate 260 corresponding thereto are the same. The main electrode 212a having the polarity and disposed at the other end of the rear substrate 250, the auxiliary electrode 222 adjacent to the main electrode, and another main electrode 212b of the front substrate 260 corresponding thereto It has the same polarity to each other, the main electrode 211a disposed at one end of the rear substrate 250, the auxiliary electrode 221 adjacent to the main electrode 211a and the main electrode of the front substrate 260 corresponding thereto. 211b and the main electrode 212a disposed at the other end of the rear substrate 250, the auxiliary electrode 222 adjacent to the main electrode, and another main electrode 212b of the front substrate 260 corresponding thereto They have opposite polarities.

When the driving voltage is applied in this way, high light emission occurs between the auxiliary electrodes 221 and 222, and one end of the main electrodes 211a and 211b, the auxiliary electrode 221 adjacent thereto, and the other main electrodes 212a and 212b and the same. Since light is emitted between adjacent auxiliary electrodes 222, luminance may be uneven.

Therefore, it is possible to arrange the protruding member to increase the brightness of the light in the position of low light emission at both ends. When the volume of the discharge space is reduced, the protruding members are disposed with the same amount of current as before, so that the plasma is more easily in contact with the upper and lower surfaces of the discharge space in which the phosphor is formed due to the reduced discharge space. Therefore, the luminance uniformity of the surface light source can be increased.

3 is a perspective view taken along the line A ₁ -A ₂ of FIG. ₂ .

Referring to FIG. 3, the light source body 300 includes a protruding member 335 in the discharge space 330 partitioned by the partition wall 340, and further includes a phosphor layer 365 and a reflective film layer 355. Can be.

The light source body 300 is formed by bonding the back substrate 350 and the front substrate 360 by the sealing material 352.

The partition wall 340 is formed on the back substrate 350 by sandblasting, laser processing, grinding or UV molding. In the manufacture of the original glass, the channel is formed by the rolling method by the rolling method, the substrate is heated and softened, and then the substrate is molded by pressing or vacuum adsorption, or the plate glass is cut to the height of the partition to apply a sealing frit to apply heat. It may also be manufactured in a manner that the present invention is not limited by the partition 340 forming method.

The phosphor layer 365 may be applied to the back substrate 350 and the front substrate 360 in the discharge space 330, or may be applied to only one substrate or to the side surface of the partition wall 340. The phosphor layer 365 converts ultraviolet light emitted from the discharge space into visible light and emits light. The phosphor layer 365 mixes red, blue, and green three-wavelength phosphors, which are excited by ultraviolet rays, to a desired color temperature to form a uniform thickness, and is applied by mixing glass powder with phosphors to increase light scattering. can do. The thickness of the phosphor layer 365 applied to the surface of the discharge space 330 is the phosphor layer 365 coated on the top of the back substrate 350 of the phosphor layer 365 coated on the bottom of the front substrate 360. It can be applied thicker than the thickness to increase the reflectance, and at the same time it is attached to the back substrate 350 also serves to prevent the impact or damage of the surface light source device due to vibration or shock.

The interior of the discharge space 330 is filled with a discharge gas. As the discharge gas, an inert gas such as xenon (Xe), neon (Ne), argon (Ar) and krypton (Kr) or a mixed gas and mercury (Hg) thereof may be used.

When a driving voltage is applied to the discharge space 330, molecules of the discharge gas in the discharge space 330 are excited, and the excited gas molecules emit ultraviolet rays while returning to the ground state. The emitted ultraviolet rays react with the phosphor layer 365 to generate visible light. This is because the phosphor absorbs high energy and short wavelength light and emits low energy and long wavelength light.

In the case where the independent discharge spaces 330 are formed by the partition walls 340 for uniform diffusion of the discharge gas, the discharge spaces may be moved between the upper portion of the partition walls 340 and the front substrate 360. Although not formed in the through groove, or not shown in the drawings, by connecting the both ends of the partition wall 'r' type partition wall 340 may further include a uniform diffusion to achieve a uniform brightness.

Referring to FIG. 3, when a high driving voltage is applied to the phosphor layer 365 at positions corresponding to the main electrodes 311 and 312 and the auxiliary electrodes 321 and 322, the phosphor is deteriorated and turned into a dark portion. The portion of the phosphor layer 365 turned into the dark portion reduces the brightness of the surface light source device and makes the brightness uneven.

Accordingly, when the protruding members 335 are disposed at positions corresponding to the main electrodes 311 and 312 and the auxiliary electrodes 321 and 322 of the discharge space 330, the protruding members 335 are the main electrodes 311 and 312 and the auxiliary electrodes 321 and 322. It serves to protect the phosphor layer 365 formed between the main electrode (311, 312) and the auxiliary electrode (321, 322) from the heat generated by the.

In addition, due to the protruding member 335, the discharge space 330 is reduced, so that a large amount of current is not required for discharge, thereby preventing a high driving voltage from being applied. Therefore, the phosphor layer 365 at positions corresponding to the main electrodes 311 and 312 and the auxiliary electrodes 321 and 322 can reduce the deterioration of the phosphor due to heat generated by applying a high driving voltage to the electrodes.

The interior of the back substrate 350 in contact with the interior of the discharge space 330 may further include a reflective film layer 355 for emitting the generated light in one direction. The reflective film layer 355 is formed on the inner surface of the back substrate 350. The reflective film layer is formed of a thermosetting or photocurable resin that is cured by heat or ultraviolet rays, thereby being coated on the inner surface of the back substrate 350 in a state of being mixed with scattering particles. The scattering particles preferably have a spherical shape and many are irregularly distributed in the coating resin. Therefore, the light directed toward the reflective film layer 355 is scattered in all directions at the interface of the scattering particles, and this process is continuously accumulated and reflected. For example, titanium oxide (TiO ₃ ), aluminum oxide (Al ₂ O ₃ ), or the like having high reflectance of light may be formed by spraying.

4 shows an embodiment of a surface light source device according to the present invention. The surface light source device 400 according to an embodiment of the present invention includes a rear substrate 450 and a front substrate 460 disposed to face each other, and the discharge space 430 at an end of the outer circumferential surface of the rear substrate and the front substrate. Main electrodes 411 and 412 formed in a longitudinal direction and a vertical direction of the second substrate, and a plurality of auxiliary electrodes 421 and 422 are formed between the main electrodes of the outer circumferential surface of the rear substrate in a direction perpendicular to the length direction of the discharge space. And protruding members 435a and 435b on the inner circumferential surface of the rear substrate in contact with the discharge space. Referring to FIG. 4, the protruding members 435a and 435b are formed from an upper edge of an auxiliary electrode side of the main electrode to an upper half edge of the main electrode of the auxiliary electrode adjacent to the main electrode in the light source body or the main electrode. It may be formed from the upper side of the sealing material forming side of the upper edge of the opposite side of the main electrode of the auxiliary electrode adjacent to the main electrode.

Since the main electrode forming portion is not actually the area displayed in the surface light emitting device, the protruding member has the same effect as long as the protruding member is formed from the top of the portion where the main electrode is formed to the upper side of the opposite electrode of the main electrode adjacent to the main electrode. Can be implemented.

Example 1

The height of discharge space is 2mm, the length of discharge path is 967mm, the width of discharge space is 10mm, the distance between main electrode and auxiliary electrode is 10mm, the width of auxiliary electrode is 5mm, the distance between auxiliary electrodes is 10mm, and the height of protruding member is 300㎛ Phosphorescent surface light source device was manufactured.

Comparative Example 1

The height of the discharge space is 2mm, the length of the discharge path is 967mm, the width of the discharge space is 10mm, the distance between the main electrode and the auxiliary electrode is 10mm, the width of the auxiliary electrode is 5mm and the distance between the auxiliary electrodes is 10mm under the same conditions as in Example 1 above. , A surface light source device having no protruding member was manufactured.

Comparative Example 2

The height of the discharge space is 2mm, the length of the discharge path is 967mm, the width of the discharge space is 10mm, the distance between the main electrode and the auxiliary electrode is 10mm, the width of the auxiliary electrode is 5mm and the distance between the auxiliary electrodes is 10mm. Under the same condition as 1, the surface light source device when the height of the protruding member was 1600 mu m was manufactured.

Test Example 1

Luminance test

Luminance according to the height of the protruding member was obtained as shown in Figures 5, 6a and 6b.

In FIG. 5, the luminance value according to the measurement point is shown as a graph as the height 436 of the protruding member according to FIG. 4 is changed.

Graph 510 shows the luminance measurement value of the surface light source device according to Comparative Example 1, it can be seen that the luminance is lowered in the electrode forming portion of the auxiliary electrode at the point provided with the auxiliary electrode. This is a phenomenon that occurs because the electrode formed in the surface light source is a portion where charge is accumulated, and the electrode forming portion acts as a relatively non-light emitting region.

In addition, the graph 520 shows the luminance measurement value of the surface light source device according to Comparative Example 2, and unlike the graph 510, the luminance is further increased at the electrode forming portion of the auxiliary electrode at the point where the auxiliary electrode is provided. And it was found. This is a phenomenon that occurs due to the relatively high amount of the plasma reaches the phosphor due to the height of the protruding member, and the secondary electron emission due to the auxiliary electrode more easily.

Graph 530 shows the luminance measurement value of the surface light source device according to the first embodiment, it can be seen that the luminance is uniform regardless of the electrode forming portion of the auxiliary electrode.

This will be more apparent with reference to FIGS. 6A and 6B. 6A is a surface light source device according to Example 1, the luminance is constant in the longitudinal direction of the discharge space, Figure 6b is a surface light source device according to Comparative Example 1, it is observed that the dark portion is formed in the forming portion of the auxiliary electrode Could.

7 illustrates a liquid crystal display according to the present invention. The surface light source unit 700 included in FIG. 7 is the same as the surface light source device, and overlapping description thereof will be omitted.

Referring to FIG. 7, a liquid crystal display device includes a liquid crystal display panel 720 including an liquid crystal, an optical member 730, and a liquid crystal display panel 720 between a thin film transistor substrate (not shown) and a color filter substrate (not shown). The surface light source portion 700 is located on the rear surface of the storage container 740 for receiving the surface light source portion and the inverter 750 for applying a voltage.

In the liquid crystal display panel 720 displaying an image, a TFT substrate (not shown) and a color filter substrate (not shown) are disposed to face each other, and the liquid crystal display panel includes a liquid crystal between the TFT substrate and the color filter substrate. When power is applied to the gate terminal of the TFT, an electric field is formed between the pixel electrode (not shown) and the common electrode, and the transmittance of light supplied from the surface light source unit 700 is changed according to the arrangement change of the liquid crystal to obtain an image.

The fixing member 710 protects the liquid crystal display 720 by preventing the liquid crystal display 720 from being damaged or detached from an external impact.

The storage container 740 is formed of a plate-shaped bottom surface and four sidewalls to accommodate the surface light source unit 700, and prevents the surface light source unit 700 from flowing.

The inverter 750 is disposed on the rear surface of the storage container 740, and applies a discharge voltage for driving to the main electrodes 711 and 712 and the auxiliary electrodes 721 and 722 of the surface light source unit 700.

The liquid crystal display device configured as described above may include an optical member 730 such as a plurality of sheets such as a diffusion plate and a prism in order to provide uniform luminance in the surface light source unit 700 and to secure a wide viewing angle.

According to the present invention, by providing a predetermined protruding member inside the discharge space, the discharge space can be narrowed to efficiently emit light, and the deterioration of the phosphor caused by the high voltage can be reduced by inducing discharge at a low driving voltage. It has the effect of making the brightness of the light source device uniform.

Claims (11)

A light source body including a rear substrate and a front substrate spaced apart from each other at predetermined intervals; A partition wall formed in the light source body to partition a discharge space; A main electrode formed at an end portion of an outer circumferential surface of the rear substrate and the front substrate in a direction perpendicular to a length direction of the discharge space; An auxiliary electrode formed between the main electrodes of the outer circumferential surface of the rear substrate in a direction perpendicular to the length direction of the discharge space; And It includes a protruding member formed on the inner peripheral surface of the back substrate in contact with the discharge space, The length of the protruding member is a length from an upper edge of the main electrode to an upper edge of an opposite side of the main electrode of the auxiliary electrode adjacent to the main electrode, and the width of the protruding member is equal to the width of the discharge space. The height of the member is a surface light source device, characterized in that formed in the range of 15 to 75% of the height of the discharge space. The method of claim 1, The protruding member is the same as the material of the partition wall material, The partition wall material is a surface light source device, characterized in that formed of a paste of a mixture of glass powder, photosensitive resin and filler. The method of claim 1, The shape of the protruding member is a surface light source device, characterized in that at least one of circular, oval, triangular or polygonal. The method of claim 1, The main electrode and the auxiliary electrode is a surface light source device, characterized in that the coating with a conductive film. The method of claim 1, And the polarity of the main electrode and the auxiliary electrode adjacent to the main electrode is the same. The method of claim 1, The light source body further includes a reflective film layer formed on the rear substrate. A surface light source unit for uniformly emitting light; A liquid crystal display panel which displays an image using light supplied from the surface light source unit; An optical member disposed between the surface light source unit and the liquid crystal display panel; A storage container accommodating the surface light source unit and the optical member; And It is installed on the back of the storage container and includes an inverter for applying a discharge voltage, The surface light source unit A light source body including a rear substrate and a front substrate spaced apart from each other at predetermined intervals; A partition wall disposed inside the light source body to define a discharge space; A main electrode formed at an end portion of an outer circumferential surface of the rear substrate and the front substrate in a direction perpendicular to a length direction of the discharge space; An auxiliary electrode formed between the main electrodes of the outer circumferential surface of the rear substrate in a direction perpendicular to the longitudinal direction of the discharge space discharge; And A protruding member is formed on an inner circumferential surface of the rear substrate in contact with the discharge space, and the protruding member has a length from an upper edge of the main electrode to an upper edge of an opposite side of the main electrode of the auxiliary electrode adjacent to the main electrode. The width of the member is the same as the width of the discharge space, the height of the protruding member is formed in the range of 15 to 75% of the height of the discharge space. The method of claim 7, wherein The protruding member includes a partition wall material, The partition wall material is formed of a paste in which glass powder, photosensitive resin and filler are mixed. The method of claim 7, wherein The protruding member has a shape of at least one of a circle, an oval, a triangle and a polygon. The method of claim 7, wherein And the main electrode and the auxiliary electrode are formed of a conductive film. The method of claim 7, wherein The polarity of the main electrode and the auxiliary electrode adjacent to the main electrode is the same.

Images