KR20070076730A - Top substrate for surface light source, surface light source device and back light unit having the same - Google Patents

Abstract

An upper substrate of a planar light source, a planar light source device, and a backlight unit having the same are provided to prevent elution of sodium ions from a glass substrate and absorption of mercury to the glass substrate by forming a metal-oxide protection layer on a bottom surface of the glass substrate corresponding to an electrode forming area. A glass substrate(10) includes an upper surface including an electrode. A metal oxide protection layer(20) is formed on a bottom surface of the glass substrate corresponding to a area in which the electrode is provided, and prevents elution of sodium ions from the glass substrate, and absorption of mercury to the glass substrate. The metal oxide protection layer has an area corresponding to the electrode forming area. A fluorescent layer is further provided on the bottom surface of the glass substrate.

Description

Top substrate of surface light source, surface light source device and back light unit having same {TOP SUBSTRATE FOR SURFACE LIGHT SOURCE, SURFACE LIGHT SOURCE DEVICE AND BACK LIGHT UNIT HAVING THE SAME}

1 is a block diagram showing an upper substrate of a surface light source including the metal oxide protective film of the present invention.

FIG. 2 is a cross-sectional view of the upper substrate shown in FIG. 1 taken along the line II ′.

3 is a block diagram showing a surface light source device including a metal oxide protective film according to Example 1 of the present invention.

FIG. 4 is a cross-sectional view of the surface light source device shown in FIG. 3 taken along the line II-II '.

FIG. 5 is a block diagram showing a surface light source device including a metal oxide protective film according to Embodiment 2 of the present invention, and FIG. 6 is a cross-sectional view of the surface light source device shown in FIG. 5 taken along the III-III 'direction.

7 is a block diagram showing a surface light source device including a metal oxide protective film according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional view of the surface light source device shown in FIG. 7 taken in the direction of IV-IV '.

9 is an exploded perspective view showing a backlight unit according to a fourth embodiment of the present invention.

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

110: surface light source body 111: first glass substrate

112: second glass substrate 120: partition wall

125: metal oxide protective film 130: upper fluorescent layer

134: lower fluorescent layer 136: reflective film

140: discharge space 150: electrode

The present invention relates to a top plate glass of a surface light source, a surface light source device and a backlight unit having the same. More particularly, the present invention relates to a top substrate and a surface light source device of a surface light source, which is used for a light source of a liquid crystal display device (LCD) and includes a metal oxide protective film, and a backlight unit having the same.

The liquid crystal display displays an image using the electrical and optical characteristics of the liquid crystal. Liquid crystal displays have the advantages of being very small in volume and light in weight compared to CRTs, etc. As a result, they are widely used in portable computers, communication devices, liquid crystal television receivers, and aerospace industries.

In order to control the liquid crystal, a liquid crystal display device requires a liquid crystal controlling part for controlling the liquid crystal and a light supplying part for supplying light to the liquid crystal. The liquid crystal control part includes a pixel electrode disposed on the first substrate, a common electrode disposed on the second substrate, and a liquid crystal interposed between the pixel electrode and the common electrode. The light supply part supplies light to the liquid crystal of the liquid crystal control part. Light sequentially passes through the pixel electrode, the liquid crystal, and the common electrode. In this case, the display quality of the image passing through the liquid crystal is greatly influenced by the luminance and luminance uniformity of the light supply part. In general, the higher the luminance and the uniformity of the luminance, the better the display quality.

The light supply part of the conventional liquid crystal display device mainly uses 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 the advantage of high luminance, long life, and has a very low heat generation compared to incandescent lamps. On the other hand, 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.

Therefore, a light supply part having a cold cathode ray tube lamp or a light emitting diode as a light source may have an optical member such as a light guide panel (LGP), a diffusion member, and a prism sheet to increase luminance uniformity. (optical member) is included. As a result, a liquid crystal display using a cold cathode ray tube lamp or a light emitting diode has a problem in that the volume and weight of the optical member are greatly increased.

In order to solve this problem, a planar light source device has been proposed. In the case of the surface light source under recent research, a system using a meandering structure uses a single channel, but the mercury content per lamp is about 20 times higher than that of a cold cathode fluorescent lamp. And soda lime glass is used to cut prices.

However, since the sodium content of the soda lime glass is very high, about 12%, when a discharge voltage is applied to the electrode to drive a lamp, a problem arises in that sodium ions are eluted from the glass substrate corresponding to the region where the electrode is provided. . Thus, sodium ions eluted from the glass substrate react with mercury contained in the discharge gas to reduce the amount of mercury gas present in the discharge space, thereby shortening the lifespan and brightness of the surface light source.

In addition, the surface light source device uses a frit which is a sealing agent for contacting the glass at a high temperature in order to secure the degree of vacuum in the discharge space. However, since the frit is exposed in the discharge space, the frit is damaged by the plasma formed in the discharge space. That is, a cathode fall region is formed at an interface between the discharge space and the sealing frit to form a pink corona discharge, thereby causing a frit degradation phenomenon in which the frit is damaged. As the frit deteriorates, fine cracks are formed in the frit to destroy the sealed state of the discharge space, and the discharge gas leaks due to the breakage of the sealed state.

A first object of the present invention for solving the above problems is to provide an upper substrate of the surface light source that can prevent the dissolution of sodium ions and deterioration of the sealing agent during operation.

In addition, a second object of the present invention is to provide a surface light source device having a structure that prevents elution of sodium ions and deterioration of a sealing agent during driving.

In addition, a third object of the present invention is to provide a backlight unit including the surface light source device.

The upper substrate of the surface light source according to an embodiment of the present invention for achieving the first object includes a glass substrate and a metal oxide protective film. The glass substrate has an upper surface on which an electrode is provided and an electrode formation region. The metal oxide protective layer is provided on the bottom surface of the glass substrate so as to correspond to the formation region of the electrode, and prevents elution of sodium ions from the glass substrate and adsorption of mercury contained in the discharge gas onto the glass substrate.

According to an aspect of the present invention, there is provided a surface light source device including a light source body including an upper substrate, a lower substrate, and partition walls, an electrode, and a metal oxide protective film. The light source body includes a lower substrate upper substrate and partition walls provided between the lower substrate and the upper substrate and partition the inner space into which the discharge gas is injected into a plurality of discharge spaces separated from each other. The electrode is provided in an electrode formation region of the light source body, and applies a voltage to an internal space of the light source body. The upper substrate includes a glass substrate having a top surface on which an electrode is provided and a metal oxide protective film. The metal oxide protective layer is provided on a bottom surface of the glass substrate so as to correspond to a region where the electrode is provided, and prevents elution of sodium ions from the glass substrate and prevention of mercury contained in a discharge gas on the glass substrate. Have

The backlight unit according to the exemplary embodiment of the present invention for achieving the third object includes a surface light source device including a light source body, an electrode, and a metal oxide protective film, an upper and lower case, an optical sheet, and an inverter. The surface light source device includes a light source body including an upper substrate, a lower substrate, and partition walls, an electrode, and a metal oxide protective film. The light source body includes a lower substrate upper substrate and partition walls provided between the lower substrate and the upper substrate and partition the inner space into which the discharge gas is injected into a plurality of discharge spaces separated from each other. The electrode is provided in an electrode formation region of the light source body, and applies a voltage to an internal space of the light source body. The upper substrate includes a glass substrate having a top surface on which an electrode is provided and a metal oxide protective film. The metal oxide protective layer is provided on a bottom surface of the glass substrate so as to correspond to a region in which the electrode is provided, and prevents elution of sodium ions from the glass substrate and mercury contained in a discharge gas to be adsorbed on the glass substrate. The upper and lower cases accommodate the surface light source device, and the optical sheet is interposed between the surface light source device and the upper case. The inverter applies a discharge voltage to the electrode for driving the surface light source device.

According to the present invention, the upper substrate of the surface light source and the surface light source device have a metal oxide film formed on the bottom surface of the glass substrate corresponding to the electrode formation region, thereby preventing sodium ions from eluting from the glass substrate when a voltage is applied to the electrode. can do. In addition, the phenomenon that mercury is adsorbed on the glass substrate can be prevented. In addition, the metal oxide film may prevent the one side of the sealing agent of the surface light source device from being exposed to the discharge gas, thereby preventing deterioration of the sealing agent. In addition, it is possible to prevent deterioration of the phosphors present in the remaining space generated by the cathode drop. Therefore, the surface light source device can prevent a problem that discharge gas does not flow out when the lamp is driven and the life of the surface light source device is shortened.

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

1 is a block diagram showing an upper substrate of a surface light source including a metal oxide protective film of the present invention, Figure 2 is a cross-sectional view of the upper substrate shown in FIG.

1 and 2, when describing the upper substrate 50 of the surface light source according to the present invention, the upper substrate has a configuration including an upper glass substrate 10 and a metal oxide protective film 20. The upper fluorescent layer 30 is further included.

The upper glass substrate 10 is a soda lime organic substrate made of a glass material and contains a sodium material. The soda lime glass substrate transmits light having a wavelength in the visible region and blocks light having a wavelength in the ultraviolet region. The soda lime glass substrate has a first surface on which an electrode (not shown) is formed and a second surface on which the metal oxide protective film 20 is formed. Hereinafter, the first surface is referred to as the top surface of the upper substrate 50, and the second surface is referred to as the bottom surface of the upper substrate 50.

The metal oxide protective film 20 is formed on the bottom surface of the upper glass substrate 10 so as to correspond to the first region E in which the electrode is formed. The metal oxide protective film 20 is formed to have an area corresponding to a region where the electrode is formed. The metal oxide protective film has a thickness of 10 to 100 µm, preferably a thickness of 30 to 100 µm, and more preferably 40 to 90 µm.

The metal oxide protective film 20 prevents sodium ions from eluting from the upper glass substrate 10 corresponding to the region where the electrode is formed when a high voltage is applied to the electrode (not shown). In addition, mercury is prevented from adsorbing on the surface of the upper glass substrate 10 by reacting with sodium ions. In addition, a frit (not shown) coupling the upper substrate 10 and the lower substrate constituting the surface light source device covers one side surface of the frit, which is the sealing agent, so as not to be exposed to plasma discharge. In addition, it is possible to prevent degradation of the fluorescent layer formed in the discharge space generated by the cathode drop.

Examples of the material constituting the metal oxide protective film include aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cerium oxide (CeO ₂ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and the like. have. These can be used individually or in mixture. Materials for forming the metal oxide protective film may be processed into a powder, paste or solution state.

In addition, the silicon oxide protective film is, for example, chemical vapor deposition (Atomic Layer Deposition), atomic layer deposition (Atomic Layer Deposition), sputtering (sputtering), dipping (dipping), fusion, spray (spray), electrostatic coating, It can be formed by applying a spin method or the like. The upper fluorescent layer included in the upper substrate is provided on the bottom surface of the upper glass substrate corresponding to a region other than the region where the electrode is provided.

Example 1

FIG. 3 is a diagram illustrating a surface light source device including the metal oxide protective film according to Embodiment 1 of the present invention, and FIG. 4 is a cross-sectional view of the surface light source device shown in FIG. 3 taken along the line II-II '.

3 and 4, the surface light source device 100 according to the first embodiment applies a voltage to the light source body 110, the metal oxide protective layer 125, and the discharge gas having an internal space into which the discharge gas is injected. It includes an electrode 150 for. As the discharge gas, mercury, helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) gas, or the like may be used.

The surface light source device 100 according to the present embodiment is a partition wall separation type. Accordingly, the light source body 110 may include a lower substrate including the first glass substrate 111, an upper substrate disposed on the first glass substrate 111, and a second glass substrate 112, and first and first materials. 2 includes a sealing member 180 disposed between edges of the glass substrates 111 and 112 to define an interior space, and partition walls 120 that divide the interior space into a plurality of discharge spaces 140. The first and second glass substrates are soda lime glass.

The partition walls 120 are arranged parallel to the inner space along the first direction, thereby partitioning the inner space into a plurality of rectangular discharge spaces 140. Bottom surfaces of the partition walls 120 may face the first glass substrate 111, and the upper surface may face the second glass substrate 112. In particular, both ends of the partition wall 120 abut the sealing member 180. Thus, each discharge space 140 is isolated from each other.

The first and second glass substrates 111 and 112 are made of a glass material that transmits visible light and blocks ultraviolet rays. The second glass substrate 112 is an emission surface from which light generated in the discharge space is emitted.

The electrode 150 is provided in the electrode formation region E on the upper surface of the second glass substrate and the electrode formation region E on the bottom surface of the first glass substrate. More specifically, the electrode is formed in a range that does not invade an active area in which white light is emitted to the front in the BLU state. Meanwhile, the electrode 150 may include a conductive tape or a conductive paste.

The metal oxide protective film 125 is formed on the bottom surface of the second glass substrate 112 so as to correspond to the electrode forming region E of the second glass substrate 112 on which the electrode is formed. The metal oxide protective layer 125 is formed to have an area corresponding to the region E in which the electrode 150 is formed. The metal oxide protective layer 125 prevents sodium ions from eluting from the second glass substrate 112 corresponding to the region where the electrode is formed when a high voltage is applied to the electrode 150. In addition, mercury is prevented from adsorbing on the surface of the second glass substrate 112 by reacting with sodium ions. In addition, a sealing agent (not shown) that couples the upper substrate and the lower substrate constituting the surface light source device covers one side of the sealing agent so as not to be exposed to the plasma discharge.

Examples of the material constituting the metal oxide protective film include aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cerium oxide (CeO ₂ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and the like. have. These can be used individually or in mixture. Materials for forming the metal oxide protective film may be processed into a powder, paste or solution state. In Example 1 of the present invention, an aluminum oxide film was used.

The metal oxide protective layer may include, for example, chemical vapor deposition, atomic layer deposition, sputtering, dipping, sanding, spraying, electrostatic coating, It can be formed by applying a spin (SPIN) method or the like. In Example 1 of the present invention, an aluminum oxide film was formed by spray-spraying only a predetermined region of the second glass substrate 112 with a powder containing aluminum oxide dissolved therein.

The reflective film 136 is formed on the first glass substrate to reflect the light directed toward the first glass substrate 111 among the light generated in the discharge space 140 toward the second organic substrate 112. . The lower fluorescent layer 134 is formed on the surface of the reflective film 136. The upper fluorescent layer 132 is formed on the bottom surface of the second glass substrate on which the metal oxide protective film 125 is not formed.

The metal oxide protective film 125 included in the surface light source device 100 prevents sodium ions from eluting in a predetermined region of the second glass substrate. In addition, mercury is not adsorbed to prevent the problem of shortening the life of the device. In addition, since the sealing agent for adhering the upper substrate and the lower substrate is not exposed to the discharge space by the metal oxide protective film, the deterioration of the sealing agent is prevented. In addition, the degradation of the fluorescent layer formed in the discharge space generated by the cathode drop is prevented.

Example 2

FIG. 5 is a block diagram showing a surface light source device including a metal oxide protective film according to Embodiment 2 of the present invention, and FIG. 6 is a cross-sectional view of the surface light source device shown in FIG. 5 taken along the III-III 'direction.

5 and 6, the surface light source device 200 according to the present exemplary embodiment may apply a voltage to the light source body 210, the metal oxide protective layer 225, and the discharge gas having an internal space into which the discharge gas is injected. For electrode 250.

The surface light source device 200 according to the present embodiment is a partition wall integrated type. Therefore, the light source body 210 includes a lower substrate including the first glass substrate 211 and an upper substrate disposed on the lower substrate and including a second glass substrate 212 formed integrally with the partition walls 220. do. The partition wall parts 220 arranged along the first direction may face the first glass substrate 211 to form a plurality of discharge spaces 240. The outermost partition walls 220 are bonded to the first glass substrate 211 through frit (S), which is a sealing agent. The partition walls 220 form arcuate discharge spaces 240 that are isolated from each other. On the other hand, the partition wall portion 220 may have a width of about 0.5 to 1.5mm.

The electrode 250 is provided in each of the electrode forming region E on the upper surface of the second glass substrate and the electrode forming region E below the first glass substrate. More specifically, the electrode 250 is formed in a range that does not invade an active area in which white light is emitted to the front in the BLU state.

The metal oxide protective film 225 is formed on the bottom surface of the second glass substrate 212 so as to correspond to the electrode forming region E of the second glass substrate 212 on which the electrode is formed. The metal oxide protective layer 225 is formed to have an area corresponding to the region E in which the electrode 250 is formed. When the high voltage is applied to the electrode 250, the metal oxide protective layer 225 prevents sodium ions from eluting from the second glass substrate 212 corresponding to the region where the electrode is formed. In addition, mercury is prevented from adsorbing on the surface of the second glass substrate 212 by reacting with sodium ions. In addition, the frit S, which is a sealing agent for coupling the upper substrate and the lower substrate constituting the surface light source device, covers one side of the frit so as not to be exposed to plasma discharge.

Examples of the material constituting the metal oxide protective film include aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and the like. These can be used individually or in mixture. In Example 2 of the present invention, cerium oxide (CeO ₂ ) was deposited by a sputtering method so as to correspond to a region where the electrode is formed.

The reflective film 236 is formed on the first glass substrate and serves to reflect the light directed toward the first glass substrate 211 among the light generated in the arcuate discharge space 240 toward the second organic substrate 212. The lower fluorescent layer 234 is formed on the surface of the reflective film 236. The upper fluorescent layer 232 is formed on the bottom surface of the second glass substrate on which the metal oxide protective film 225 is not formed.

The metal oxide protective film 225 included in the surface light source device 200 not only prevents sodium ions from eluting in a predetermined region of the second glass substrate, but also prevents adsorption of mercury to shorten the life of the device. prevent. In addition, since the sealing agent adhering the upper substrate and the lower substrate is not exposed to the discharge space by the metal oxide protective film, the phenomenon of deterioration of the sealing agent is prevented. In addition, the degradation of the fluorescent layer formed in the discharge space generated by the cathode drop is prevented.

Example 3

FIG. 7 is a configuration diagram illustrating a surface light source device including the metal oxide protective film according to Embodiment 3 of the present invention, and FIG. 8 is a cross-sectional view of the surface light source device shown in FIG. 7 taken along the line IV-IV '.

Referring to FIGS. 7 and 8, the surface light source device 300 according to the present exemplary embodiment includes a metal oxide protective film 325 of a light source body 310 having an internal space into which a discharge gas is injected, and a voltage applied to the discharge gas. Electrode 350.

The surface light source device 300 according to the present embodiment is a partition wall type. Accordingly, the light source body 310 includes a lower substrate including the first glass substrate 311 and an upper substrate including a second glass substrate 312 disposed on the lower substrate and integrally formed with the partition portions 320. do. The partition walls 320 arranged along the first direction are opposed to the first glass substrate 311 so as to be separated from each other, and a plurality of trapezoidal discharge spaces 340 are formed. The outermost partition walls 320 are bonded to the first glass substrate 311 through the frit S, which is a sealing agent. In particular, in order to suppress a current flowing between neighboring discharge spaces 340 through the partition portion 320, the partition portions 320 may have a width of about 2 to 5 mm, preferably 4 mm. Can have.

The electrode 350 is provided in each of the electrode forming region E on the upper surface of the second glass substrate 312 and the electrode forming region E below the first glass substrate. More specifically, the electrode 350 is formed within a range that does not invade an active area in which white light is emitted to the front in the BLU state.

The metal oxide protective layer 325 is formed on the bottom surface of the second glass substrate 312 so as to correspond to the electrode forming region E of the second glass substrate 312 on which the electrode is formed. The metal oxide protective film 325 is formed to have an area corresponding to the region E in which the electrode 350 is formed. The metal oxide protective layer 325 prevents sodium ions from eluting from the second glass substrate 312 corresponding to the region where the electrode is formed when a high voltage is applied to the electrode 350. In addition, mercury is prevented from adsorbing on the surface of the second glass substrate 312. In addition, the frit S, a sealing agent for coupling the upper substrate and the lower substrate constituting the surface light source device, covers one side surface of the frit S so as not to be exposed to plasma discharge. As the metal oxide protective film in Example 3 of the present invention, a yttrium oxide film formed by a spray injection method was used.

The reflective film 370 reflects the light directed toward the first glass substrate 311 among the light generated in the discharge space 340 toward the second glass substrate 312. The first fluorescent layer 361 is formed on the surface of the reflective layer 370. The second fluorescent layer 362 is formed on the bottom surface of the second glass substrate 312.

The surface light source device 300 having the above-described configuration includes an upper substrate having a metal oxide protective film 325, which not only prevents sodium ions from eluting in a predetermined region of the second glass substrate to which power is applied, but also prevents mercury from being released. This prevents the problem of shortening the life of the device because it is not adsorbed. In addition, since the sealing agent S for adhering the upper substrate and the lower substrate is not exposed to the discharge space by the metal oxide protective film, the deterioration of the sealing agent is prevented.

Example 4

4 is an exploded perspective view showing a backlight unit according to a fourth embodiment of the present invention.

4, the backlight unit 1000 according to the present embodiment includes the surface light source device 300, the upper and lower cases 1100 and 1200, the optical sheet 900, and the inverter 1300 according to the third embodiment. do.

Since the surface light source device 300 has substantially the same configuration as the surface light source device shown in FIG. 3, the description of the metal oxide protective film included in the surface light source device 300 and the surface light source device will be omitted. Meanwhile, the surface light source devices according to the other embodiments described above may be employed in the backlight unit 1000.

The lower case 1200 includes a bottom portion 1210 and a plurality of sidewalls 1220 extending to form an accommodation space from an edge of the bottom portion 1210 to accommodate the surface light source device 300. The surface light source device 300 is accommodated in the storage space of the lower case 1200.

The inverter 1300 is disposed on the rear surface of the lower case 1200 and generates a discharge voltage for driving the surface light source device 300. The discharge voltage generated from the inverter 1300 is applied to the electrodes 350 of the surface light source device 300 through the first and second power lines 1352 and 1354, respectively.

The optical sheet 900 may include a diffuser plate (not shown) for uniformly diffusing the light emitted from the surface light source device 300, and a prism sheet (not shown) for imparting straightness to the diffused light.

The upper case 1100 is coupled to the lower case 1200 to support the surface light source device 300 and the optical sheet 900. The upper case 1100 prevents the surface light source device 300 from being separated from the lower case 1200.

Meanwhile, a liquid crystal display panel (not shown) for displaying an image may be disposed on the upper case 1100.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples. However, an Example is for illustrating this invention and does not limit this invention.

Example 5

An aluminum oxide film having a thickness of about 30 μm on both sides of the bottom surface of the upper glass substrate corresponding to the electrode forming region of the upper glass substrate on which the electrode is formed and a thickness of about 30 μm on the bottom of the upper glass substrate on which the aluminum oxide film is not formed The upper substrate was formed by forming the upper fluorescent layer having the same. Subsequently, a reflective film and a lower fluorescent layer were sequentially formed on the lower glass substrate provided with the electrode to form a lower substrate. Subsequently, the frit, which is a sealing agent, was applied and heated on the bottom of the upper substrate, and the upper substrate was sealed to the lower substrate. Subsequently, mercury gas and inert gas were injected therein, and then sealed to prepare a surface light source.

Example 6

A surface light source was manufactured in the same manner as in Example 5, except that a silicon oxide film having a thickness of 60 μm was formed instead of the aluminum oxide film.

Example 7

A surface light source was manufactured in the same manner as in Example 5, except that a yttrium oxide film having a thickness of 90 μm was formed instead of the aluminum oxide film. .

Comparative example

The upper substrate was formed by forming an upper fluorescent layer having a thickness of about 30 μm on the bottom of the upper glass substrate on which the electrode was formed. Subsequently, a reflective film and a lower fluorescent layer were sequentially formed on the lower glass substrate provided with the electrode to form a lower substrate. Subsequently, the frit, which is a sealing agent, was applied and heated on the bottom of the upper substrate, and the upper substrate was sealed to the lower substrate. Subsequently, a mercury gas and an inert gas were injected therein and then sealed to prepare a surface light source.

Evaluation example

In order to examine the effects of the surface light sources prepared in Examples 5 to 7 and Comparative Examples, the surface light sources were tested for 500 hours at a high temperature of 70 ° C. to change the frit and the adsorption of mercury. Were respectively measured. The results are shown in Table 1.

TABLE 1

division  Metal oxide shield Frit changes  Mercury adsorption Example 5 Aluminum oxide film No change Not adsorbed Example 6 Silicon oxide film No change Not adsorbed Example 7 Yttria film No change Not adsorbed Comparative example  it does not exist Change occurs Adsorbed

When the metal oxide protective film was not applied as in Comparative Example, it was found that discoloration occurred in the frit after about 54 hours. On the other hand, the surface light source device to which the metal oxide protective film was applied as in Examples 5 to 7 did not cause discoloration of the frit after about 150 hours.

In the upper substrate of the surface light source according to the present invention, a metal oxide protective film is formed on the bottom surface of the glass substrate corresponding to the electrode formation region, thereby preventing sodium ions from eluting from the glass substrate on which the electrode is applied when a voltage is applied to the electrode. can do. In addition, the phenomenon that mercury is adsorbed on the glass substrate can be prevented. In addition, since the metal oxide protective film covers one side surface of the sealing agent of the surface light source device and prevents the sealing agent from being exposed to the discharge gas, deterioration of the frit can be prevented when the surface light source is driven. Therefore, in the surface light source device, discharge gas does not leak when the lamp is driven, and the problem of shortening the life of the surface light source device is prevented.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (13)

A glass substrate having an upper surface provided with an electrode; And A surface formed on a bottom surface of the glass substrate so as to correspond to a region where the electrode is provided, and including a metal oxide protective layer for preventing elution of sodium ions from the glass substrate and for preventing mercury contained in a discharge gas from being adsorbed onto the glass substrate Upper substrate of the light source device. The upper substrate of the surface light source device according to claim 1, wherein the metal oxide protective film has an area corresponding to the electrode formation region. The upper substrate of the surface light source device according to claim 1, wherein a bottom surface of the glass substrate is further provided with a fluorescent film. The upper substrate of the surface light source device according to claim 4, wherein the fluorescent film is provided on a bottom surface of a glass substrate corresponding to a region other than the region where the electrode is provided. The group of claim 1, wherein the metal oxide protective layer is formed of aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cerium oxide (CeO ₂ ), zirconium oxide (ZrO ₂ ), and titanium oxide (TiO ₂ ). The upper substrate of the surface light source device, characterized in that made of at least one material selected from. The upper substrate of the surface light source device according to claim 1, wherein the metal oxide protective film has a thickness of 10 to 100 µm. A light source body having a lower substrate, an upper substrate, and partition walls provided between the lower substrate and the upper substrate and partitioning an inner space into which discharge gas is injected into a plurality of discharge spaces separated from each other; And It is provided in the electrode forming region of the light source body, and includes an electrode for applying a voltage to the internal space of the light source body, The upper substrate includes a glass substrate having an upper surface provided with electrodes and a bottom surface of the glass substrate so as to correspond to a region in which the electrode is provided, and mercury contained in the discharge gas and the discharge of sodium ions from the glass substrate is contained in the glass. A surface light source device comprising a metal oxide protective film for preventing adsorption on a substrate. The surface light source device of claim 7, wherein the upper substrate or the lower substrate has a plurality of partitions that partition the discharge space of the surface light source device. The group of claim 7, wherein the metal oxide protective film is formed of aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cerium oxide (CeO ₂ ), zirconium oxide (ZrO ₂ ), and titanium oxide (TiO ₂ ). Surface light source device comprising at least one material selected from. 8. The surface light source device of claim 7, wherein the metal oxide protective film has an area corresponding to the electrode formation region. The surface light source device of claim 7, wherein a bottom surface of the glass substrate further comprises a fluorescent film. 12. The surface light source device according to claim 11, wherein the fluorescent film is provided on a bottom surface of a glass substrate corresponding to a region other than the region where the electrode is provided. A light source body having an lower substrate, an upper substrate, and partition walls provided between the lower substrate and the upper substrate and partitioning an inner space into which discharge gas is injected into a plurality of discharge spaces separated from each other, and forming an electrode of the light source body. An electrode provided in an area and configured to apply a voltage to an internal space of the light source body, wherein the upper substrate has a glass substrate having an upper surface on which an electrode is provided and a bottom surface of the glass substrate so as to correspond to an area in which the electrode is provided. A surface light source device provided with a metal oxide protective film for preventing elution of sodium ions from the glass substrate and for preventing mercury contained in a discharge gas from being adsorbed on the soda lime glass substrate; Upper and lower cases accommodating the surface light source device; An optical sheet interposed between the surface light source device and the upper case; And And an inverter for applying a discharge voltage for driving the surface light source device to the electrode.

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