KR20080052942A - Cold cathod flourescent lamp and fabricating method thereof - Google Patents

Abstract

A CCFL and a manufacturing method thereof are provided to suppress a temperature rise in an electrode portion by increasing a coupling property between an electrode and a cesium oxide. A CCFL(Cold Cathode Fluorescent Lamp) includes a discharge tube(102), a fluorescent material(106), electrodes(110), and a mixture of a cesium oxide and other inorganic oxides. The fluorescent material is formed on an inner surface of the discharge tube. The electrodes are formed inside the discharge tube. The mixture is formed on a surface of the electrode. The inorganic oxide contains at least one of silicon oxide, aluminum oxide, and titanium oxide. The inorganic material contains at least two of silicon oxide, aluminum oxide, and titanium oxide.

Description

Cold Cathode Fluorescent Lamp and its Manufacturing Method {Cold Cathod Flourescent Lamp and Fabricating Method

1 is a cross-sectional view showing a conventional cold cathode fluorescent lamp.

FIG. 2 is an enlarged cross-sectional view of an electrode unit of the cold cathode fluorescent lamp of FIG. 1; FIG.

3A is a graph showing a temperature distribution during initial discharge of a cold cathode fluorescent lamp.

3B is a graph showing a temperature distribution after 1000 hours of cold cathode fluorescent lamp.

4 is a cross-sectional view illustrating a mercury agglomeration phenomenon of the cold cathode fluorescent lamp shown in FIG. 1.

5 is a cross-sectional view showing a cold cathode fluorescent lamp according to an embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of an electrode unit of the cold cathode fluorescent lamp of FIG. 5; FIG.

7 is an enlarged cross-sectional view of an electrode part of a cold cathode fluorescent lamp according to another embodiment of the present invention;

8 is a graph showing a change in temperature according to the position of the electrode unit of the prior art and the present invention.

<Description of Symbols for Main Parts of Drawings>

102 discharge tube 104 inert mixed gas

106: phosphor 108: terminal

110 electrode 112 Koba pin

114: bead glass 116: inorganic oxide

The present invention relates to a lamp used as a light source, and particularly relates to a cold cathode fluorescent lamp and a method for manufacturing the same, which can maintain a constant temperature of the electrode unit and prevent merging of mercury even when used for a long time.

In general, a cold cathode fluorescent lamp is used as a light source for a backlight for irradiating uniform light from the back of a liquid crystal panel to a liquid crystal display device used for electronic devices such as a personal computer.

1 and 2, a conventional cold cathode fluorescent lamp includes a discharge tube 2, an inert mixed gas 4 injected into an interior space of the discharge tube 2, and a phosphor coated on an inner wall surface of the discharge tube 2 ( 6), an internal electrode 10 formed at both ends of the discharge tube 2, a terminal 8 for applying power supplied from a power source (not shown) to the internal electrode 10, an internal electrode 10, and a terminal. Cova pins 12 for electrically connecting the electrodes 8, bead glass 14 surrounding the Cova pins 12 to protect the Cova pins 12 penetrating the discharge tube 2, and an internal electrode. It consists of cesium oxide 16 applied on (10).

The discharge tube 2 is manufactured in the form of a cylinder, and the inert mixed gas 4 is injected into the inner space. The inert mixed gas 4 contains neon (Ne) and argon (Ar) in a certain ratio and contains a small amount of mercury (Hg). The internal electrode 10 is manufactured in the form of a cup, and cesium oxide 16 is coated on the surface of the internal electrode 10.

The cesium oxide 16 is a metal oxide that gives off electrons easily due to a small work function, and Cs ₂ O or Cs ₂ SO ₄ is mainly used. This cesium oxide 16 is used for the purpose of improving dark startup. Dark startup is a cold cathode fluorescent lamp in which it is difficult to generate secondary electrons and plasma discharge when there is no initial electron in the discharge space inside when the cold cathode fluorescent lamp is exposed to a dark environment below 1 [lux] for a long time. Plasma discharge does not occur or the discharge is delayed at the beginning of applying the driving voltage to the electrodes of the. Since cesium oxide 16 readily emits electrons, when the initial driving voltage is applied to the cold cathode fluorescent lamp even in a dark startup environment, the cesium oxide 16 emits initial electrons to rapidly generate secondary electrons, thereby causing plasma discharge. Make it easy to get up. In addition, cesium oxide 16 is applied on the internal electrode 10 to lower the discharge driving voltage of the internal electrode 10 to improve luminous efficiency. In addition, the cesium oxide 16 lowers the temperature of the internal electrode 10 to reduce the temperature variation of the internal electrodes 10 respectively installed at both ends of the discharge tube 2.

Looking at the discharge principle of the cold cathode fluorescent lamp, when the driving power from the external power source is applied to the internal electrode 10 through the terminal 8, the cold cathode fluorescent lamp causes a discharge. The electrons emitted from the internal electrode 10 due to this discharge collide with the inert mixed gas 4 in the discharge space in the discharge tube 2 to generate ultraviolet rays. In other words, a discharge occurs in the inert mixed gas 4 so that the electrons of the inert mixed gas 4 are transferred from the ground state to the excited state. The transition from the excited state to the ground state is again performed. In this process, the inert mixed gas 4 generates ultraviolet rays, and the ultraviolet rays cause the discharge tube phosphor 6 to emit light.

During the initial discharge of the cold cathode fluorescent lamp, as shown in FIG. 3A, the temperature of the first electrode part 20 in which cesium oxide 16 is coated on the internal electrode 10 is not applied to the cesium oxide 16. It can be seen that it is lower than the two electrode portions 30. This is because the cesium oxide 16 lowers the temperature of the first electrode portion 20 of the cold cathode fluorescent lamp during the initial discharge.

However, when the cold cathode fluorescent lamp is used for a long time and the temperature of the electrode part is examined after, for example, 1000 hours (1000hr), it can be seen that the temperature of the first electrode part 20 is increased as shown in FIG. 3B. This is because the cesium oxide 16 applied on the first electrode portion 20 has lost the function of lowering the temperature after long time use, because the cesium oxide 16 is the internal electrode of the first electrode portion 20. It is because it apply | coated in (10) in aqueous solution state. In other words, the bonding state between the internal electrode 10 and the cesium oxide 16 is maintained simply by electrostatic attraction without any chemical or physical bonding force, so that the bond between the internal electrode 10 and the cesium oxide 16 is broken. Because.

In addition, in the conventional cold cathode fluorescent lamp, mercury agglomeration phenomenon 18 appears between the internal electrode 10 and the cobar pin 12 as shown in FIG. 4. This is because a high temperature is generated in the internal electrode 10, but the temperature is lower than that of the internal electrode 10 in the cobar fin 12 having a low thermal conductivity. Due to this temperature difference, mercury is agglomerated between the internal electrode 10 and the coba pin 12.

Accordingly, it is an object of the present invention to provide a cold cathode fluorescent lamp and a method of manufacturing the same, which can maintain a constant temperature of an electrode part and prevent merging of mercury even when used for a long time.

In order to achieve the above object, a cold cathode fluorescent lamp according to an embodiment of the present invention, the discharge tube, the phosphor formed on the inner surface of the discharge tube, the electrodes provided in the discharge tube, cesium oxide formed on the surface of the electrode and the And a mixture of different inorganic oxides.

The inorganic oxide includes any one of silicon oxide, aluminum oxide and titanium oxide.

The inorganic oxide includes a mixture of two or more kinds of silicon oxide, aluminum oxide, and titanium oxide.

The cold cathode fluorescent lamp further includes an external terminal to which external power is supplied, a cobar pin electrically connecting the electrode and the external terminal, and a bead glass surrounding the cobar pin.

An inert gas including mercury (Ne) and argon (Ar) and mercury (Hg) are injected into the discharge tube.

A method of manufacturing a cold cathode fluorescent lamp according to an embodiment of the present invention is a method of manufacturing a cold cathode fluorescent lamp having a discharge tube, a phosphor formed on the inner surface of the discharge tube, the electrode installed in the discharge tube, cesium oxide and other inorganic Obtaining a mixed liquid of an oxide binder, coating and drying the mixed liquid on the electrode, and baking the dried mixed liquid.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 to 8.

First Example

5 and 6, the cold cathode fluorescent lamp according to the first embodiment of the present invention includes a discharge tube 102, an inert mixed gas 104 injected into an interior space of the discharge tube 102, and a discharge tube 102. A phosphor 108 applied to the inner wall surface, internal electrodes 110 formed at both ends of the discharge tube 102, a terminal 108 for applying driving power from an external power source to the internal electrode 110, Cova pins 112 that electrically connect between the internal electrode 110 and the terminal 108, and bead glass surrounding the Cova pins 112 to protect the Cova pins 112 penetrating the discharge tube 102. 114 and an inorganic oxide 116 coated on the internal electrode 110 to strengthen the bonding force between the internal electrode 110 and cesium oxide.

The cobar pin 112 and the terminal 118 are connected in glass beads bonded to both ends of the discharge tube 102.

Discharge tube 102 is manufactured in the form of a cylinder and the inert mixed gas 104 is injected into the inner space. The inert mixed gas 104 is mixed in a ratio of neon (Ne) and argon (Ar) and a small amount of mercury (Hg). The internal electrode 110 is manufactured in the form of a cup, and an inorganic oxide 116 is coated on the surface of the internal electrode 110.

The inorganic oxide 116 includes cesium oxide and a silicon oxide (SiO ₂ ) binder added to the cesium oxide. The inorganic oxide 116 is locally coated on the internal electrode 110 as shown in FIG. 6, or coated on the entire surface of the internal electrode 110 as shown in FIG. 7.

Cesium oxide is an oxide that gives off electrons easily due to a small work function, and Cs ₂ O or Cs ₂ SO ₄ is mainly used. Such cesium oxide is used for the purpose of improving dark startup. In addition, cesium oxide is locally or entirely coated on the internal electrode 110 to lower the discharge driving voltage of the internal electrode 110 to improve luminous efficiency, and to lower the temperature of the internal electrode 110 at both ends of the discharge tube 102. The temperature deviation of each of the internal electrodes 110 is reduced.

The silicon oxide binder enhances the bonding force between the internal electrode 110 of the cold cathode fluorescent lamp and cesium oxide to prevent the temperature of the electrode portion of the cold cathode fluorescent lamp from increasing even when the cold cathode fluorescent lamp is driven for a long time.

This silicon oxide binder has an electrical property of pulling mercury in the discharge tube 102. Accordingly, the silicon oxide binder pulls mercury during driving of the lamp, thereby preventing merging of mercury between the internal electrode 110 and the cobar pin 112.

Referring to the method of forming the inorganic oxide 116 on the internal electrode 110, first, cesium oxide and silicon oxide binder are mixed. The mixed solution is coated on the internal electrode 110 of the cold cathode fluorescent lamp, followed by hot air drying. Thereafter, the silicon oxide binder is fired by heat treatment at a temperature of 200 to 300 ° C. As the silicon oxide binder, a silicon oxide provider developed by "Ludox" can be used.

Looking at the discharge principle of such a cold cathode fluorescent lamp, when a predetermined driving power is applied to the internal electrode 110 from the power source through the terminal 108, the cold cathode fluorescent lamp causes a discharge. The electrons emitted from the internal electrode 110 due to this discharge collide with the inert mixed gas 104 in the discharge space in the discharge tube 102 to generate ultraviolet rays. In other words, a discharge occurs in the inert mixed gas 104 so that the electrons of the inert mixed gas 104 transition from the ground state, which is the initial state, to the excited state. The excited electrons transition back to the ground state, in which the inert mixed gas 104 generates ultraviolet rays. This ultraviolet light emits the phosphor 106 coated on the inner wall of the discharge tube 102 to produce visible light.

The cold cathode fluorescent lamp according to the embodiment of the present invention does not increase the temperature at the electrode portion even when used for a long time as shown in FIG.

In detail, when the cold cathode fluorescent lamp is used for a long time and looks at the temperature distribution of the electrode part, for example, after 1000 hours (1000hr), the first electrode of the internal electrode 110 coated with cesium oxide by heat generated by sputtering is examined. The temperature ① is the highest and is reduced to the second temperature ② due to the heat movement in the internal electrode 110, and the thermal conductivity is reduced to the third temperature ③ at the low Koba fin 112. Here, in the related art, the temperature gradient according to the position of the electrode portion is large, and the temperature difference appears severely in the electrode portion. However, in the present invention, the temperature gradient according to the position of the electrode portion is gentler than that of the conventional art. As such, since there is almost no temperature difference between the internal electrode 110 and the cobar pin 112, merging of mercury may be prevented between the internal electrode 110 and the cobar pin 112.

2nd Example

In the second embodiment of the present invention, a mixture of cesium oxide and aluminum oxide (Al ₂ O ₃ ) is coated on the internal electrode 110.

Cesium oxide is dissolved in water and its surface tension is not uniform. When the aluminum oxide provider is formed on the internal electrode 110, cesium oxide may penetrate between the particles of the aluminum oxide so that the cesium oxide may have a uniform thickness on the internal electrode 110. As a result, in the second embodiment of the present invention, cesium oxide is widely formed on the internal electrode 110 in a uniform thickness using an aluminum oxide binder.

Looking at the method of forming a mixture of cesium oxide and aluminum oxide on the internal electrode 110, first, the cesium oxide and aluminum oxide binder is uniformly mixed. Subsequently, the present invention is coated on the internal electrode 110 of the cold cathode fluorescent lamp, dried by hot air, and then fired.

The third Example

The third embodiment of the present invention coats a mixture of cesium oxide and titanium oxide (TiO ₂ ) on the internal electrode 110.

Titanium oxide is a binder that firmly binds cesium oxide on the internal electrode 110.

Referring to the method of forming cesium oxide and titanium oxide on the internal electrode 110, first, the cesium oxide and the titanium oxide binder are uniformly mixed. Subsequently, the present invention is coated with the mixed solution on the internal electrode 110 of the cold cathode fluorescent lamp, dried by hot air, and then fired.

Meanwhile, in another embodiment of the present invention, an inorganic oxide including a mixture of two or more of silicon oxide, aluminum oxide, and titanium oxide may be mixed with cesium oxide and coated on the internal electrode 110.

As described above, in the method of manufacturing a cold cathode fluorescent lamp according to an embodiment of the present invention, an inorganic oxide made of silicon oxide, aluminum oxide, titanium oxide, or a mixed composition thereof is mixed with cesium oxide and cesium oxide, and the mixed liquid is internally mixed. Coating on the electrode. Therefore, the cold cathode fluorescent lamp according to the present invention can suppress the temperature rise of the electrode portion even by using a lamp for a long time by strengthening the bonding force between the electrode and cesium oxide due to the inorganic oxide. In addition, even if the cold cathode fluorescent lamp according to the present invention is driven for a long time there is little temperature difference between the electrode and the coba pin can prevent the merging of mercury between the electrode and the coba pin.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (8)

Discharge tube, A phosphor formed on an inner surface of the discharge tube, Electrodes installed in the discharge tube, And a mixture of cesium oxide and other inorganic oxides formed on the surface of the electrode. The method of claim 1, The inorganic oxide cold cathode fluorescent lamp comprising any one of silicon oxide, aluminum oxide, titanium oxide. The method of claim 1, The inorganic oxide is a cold cathode fluorescent lamp comprising a mixture of two or more of silicon oxide, aluminum oxide, titanium oxide. The method of claim 1, External terminal to which external power is supplied, Cobar pin for electrically connecting between the electrode and the external terminal, Cold-polar fluorescent lamp further comprises a bead glass surrounding the coba pin. The method of claim 1, The discharge tube is cold cathode fluorescent lamp, characterized in that the inert gas including mercury (Ne) and argon (Ar) and mercury (Hg) is injected. In the manufacturing method of the cold cathode fluorescent lamp having a discharge tube, a phosphor formed on the inner surface of the discharge tube, the electrode provided in the discharge tube, Obtaining a mixed liquid of cesium oxide and other inorganic oxide binders, Coating and mixing the mixed solution on the electrode; The method of manufacturing a cold cathode fluorescent lamp comprising the step of firing the dried mixed solution. The method of claim 6, The inorganic oxide is a method of manufacturing a cold cathode fluorescent lamp comprising any one of silicon oxide, aluminum oxide, titanium oxide. The method of claim 6, The inorganic oxide is a method of manufacturing a cold cathode fluorescent lamp comprising a mixture of two or more of silicon oxide, aluminum oxide, titanium oxide.

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