KR20080101948A - Ccfl lamp using molybdenum- nikel alloy electrode - Google Patents

Abstract

A cold cathode fluorescent lamp using the nickel alloy electrodes is provided to resolve the LCD image problem by lowering the electrode portion heat-generating temperature of lamp. The cold cathode fluorescent lamp includes the electrode which is arranged at the both sides of inner space of the glass tube in order to discharge. The fluorescent substance(2) is coated onto the inner wall of the glass tube(1) which is shut tightly. The electrode is made of the nickel alloy in which the molybdenum component is contained. The electrode portion heat-generating temperature of lamp is lowered and the LCD image problem is resolved. At the same time, the effect of sputtering is suppressed and the lifetime of lamp is lengthened.

Description

Cold cathode fluorescent lamp using molybdenum-containing nickel alloy electrode {CCFL LAMP USING MOLYBDENUM- NIKEL ALLOY ELECTRODE}

1 is a view showing a cold cathode fluorescent lamp according to the present invention,

2 is a view showing an electrode of a cold cathode fluorescent lamp according to the present invention,

3 is a view illustrating an electrode sputtering phenomenon with time of a cold cathode fluorescent lamp according to the present invention;

4 is a view showing an electrode metal structure of a cold cathode fluorescent lamp according to the present invention;

5 is a hardness graph according to the heat treatment temperature of the cold cathode fluorescent lamp according to the present invention.

* Explanation of symbols for main parts of the drawings

1: glass tube 2: phosphor

3: mercury vapor 4: cup type electrode

5: Lead 6: Argon + Neon Rare Gas

The present invention relates to a cold cathode fluorescent lamp, and more particularly, employing a nickel alloy electrode containing molybdenum component, the advantages of easy processing and low material cost of nickel and excellent thermal conductivity and sputtering resistance of molybdenum It relates to a cold cathode fluorescent lamp using.

In general, a liquid crystal display (LCD) is widely used as a flat panel display because it can be driven using low power and has a vivid color reproduction capability.

However, unlike CRTs and PDPs, LCDs are non-light emitting devices that do not emit light directly, and require a separate backlight unit using fluorescent lamps to irradiate light from the back of the LCD panel to the panel. do.

In particular, in recent years, flat panel displays such as LCDs are becoming larger in size, and various types of backlight devices have been developed to function as backlights for such large display devices.

The fluorescent lamp installed in the backlight device is classified into an internal electrode fluorescent lamp in which the electrode is built in the fluorescent lamp according to the position of the electrode, and an external electrode fluorescent lamp in which the electrode is installed outside. It can be divided into a flat fluorescent lamp having a discharge space formed between the flat glass tube of uniform intervals. Among them, a cold cathode fluorescent lamp (CCFL: Cold Cathode Fluorescent Lamp), which is excellent in light emitting efficiency and has a long life, is mainly used as a backlight light source of a large LCD.

In the general structure of the cold cathode fluorescent lamp, the phosphor is coated on the inner wall of the glass tube, and a mixed gas using mercury (Hg) for discharging is filled therein, and electrodes are provided on both sides of the glass tube.

In this structure, when an electric field is applied to both electrodes, electrons are emitted from the electrodes and they collide with mercury vapor particles inside the lamp to emit ultraviolet rays. The emitted ultraviolet rays again excite the phosphor coated on the inner wall of the lamp to emit visible light, thereby functioning as a light source. Here, the electrode, mercury, and the phosphor influence the life of the lamp, and in particular, the material of the electrode is important because the electrode has a great influence on the life of the lamp.

Currently commonly used electrodes include nickel (Ni), molybdenum (Mo), and niobium (Nb) metals, and nickel metals are most commonly used.

Nickel metal is ductile and has excellent electrode processing, and has an advantage of easy electron emission at high voltage. On the contrary, molybdenum or niobium metals have a lower work function than nickel, and have excellent sputtering and thermal conductivity, but have brittleness, which makes electrode processing difficult and expensive metal materials.

However, nickel metal is sputtered on the surface when a high voltage is applied in a vacuum state, and finally a hole is formed on the surface of the electrode. For this reason, molybdenum or niobium metal having a higher melting point than nickel metal is used. It is done.

In the LCD using a cold cathode fluorescent lamp using a nickel electrode, a problem such as white spots or yellowing occurs in an image on the LCD due to the heat generation of the electrode part when a high voltage and a plurality of lamps are applied.

The present invention has been proposed to solve the above problems, an object of the present invention is to add a molybdenum component to the nickel metal, to lower the heating temperature of the electrode portion of the lamp to improve the LCD image problem, and at the same time suppress the sputtering effect By extending the life of the lamp, and lowering the tube voltage to provide a cold cathode fluorescent lamp that can improve the power consumption efficiency.

In the cold cathode fluorescent lamp of the present invention for achieving the above object is a fluorescent cathode is coated on the inner wall of the sealed glass tube, the electrode in the cold cathode fluorescent lamp is disposed on both sides of the inside of the glass tube, the electrode It is made of nickel alloy containing molybdenum component to lower the heating temperature of the electrode part of the lamp to improve the LCD image problem, at the same time to suppress the sputtering effect, to prolong the lamp life, and to reduce the tube voltage to improve the power consumption efficiency. It features.

In addition, the molybdenum content added to the nickel metal used as the electrode may be composed of 3% to 15% by weight, and the electrode may be a cup-shaped electrode to which a lead wire is connected.

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

1 is a cross-sectional view showing the internal structure of a cold cathode fluorescent lamp according to an embodiment of the present invention, Figure 2 is a detailed cross-sectional view showing the structure of an electrode according to an embodiment of the present invention.

Referring to FIG. 1, a cold cathode fluorescent lamp according to the present invention (hereinafter referred to as 'CCFL') is a sealed glass tube 1, and a phosphor 2 is coated on an inner wall thereof, and discharge is discharged on both sides of the glass tube 1. The metal electrode 4 for the structure is arranged, a nickel alloy containing a molybdenum component is applied to the metal electrode (4).

In more detail, the cup-shaped metal electrodes 4 are disposed at both ends of the glass tube 1, and the electrodes 4 are connected to the lead wires 5 and disposed on both sides of the glass tube 1, respectively. For the electrode 4 used in the CCFL, an electrode made of nickel (Ni) alloy containing a molybdenum (Mo) component is used.

The sealed glass tube 1 has a vacuum of about 50 to 120 Torr, and is filled with mercury (Hg) 3 and mixed gas 6 such as argon (Ar) and neon (Ne).

When the CCFL having the above structure is applied with power through the electrodes 4 on both sides, electrons are emitted from the electrodes 4, and electrons collide with the mixed gas particles 6 in the discharge space to emit ultraviolet rays. The emitted ultraviolet rays again excite the phosphor 2 applied to the inner wall of the lamp to cause the lamp to emit light. That is, electrons are directly emitted from the electrode 4 inside the glass tube 1, and electrons of the mixed gas 6 are ionized to emit ultraviolet rays, thereby causing the phosphor 2 on the inner wall of the glass tube to emit light.

In particular, in the CCFL according to the embodiment of the present invention, a metal electrode made of a nickel alloy containing 3% to 15% molybdenum is used. Since the electrode 4 of the CCFL is grounded on one side and a high voltage power is continuously applied to the other electrode to induce discharge in the glass tube 1, the electrode 4 is sputtered over time due to the application of a high voltage. The more holes are generated in the surface of the electrode.

The electrode 4 made of molybdenum-containing nickel alloy has a dense structure even in the metal structure as shown in (a) of FIG. 4 and has a high hardness value of the electrode state. Molybdenum, which has high thermal conductivity and low electrical resistance, facilitates the movement of free and hot electrons inside the metal bond of the alloy electrode, thereby lowering the tube voltage inside the lamp and facilitating heat transfer through the lead wire, thereby lowering the lamp heat temperature. give.

The electrode part temperature, tube voltage comparison, electrode surface change with time, metal structure comparison, and temperature for the case of applying the nickel electrode according to the prior art and the case of the nickel alloy containing the molybdenum component according to the present invention Look at the hardness comparisons respectively through experimental examples.

Experimental Example 1

Experimental Example 1 relates to a change in the surface of the electrode over time with respect to the CCFL according to the prior art and the embodiment of the present invention, the results are shown in FIG. In FIG. 3, (a) shows the first electrode state (0 hours), (b) shows the state of the molybdenum-containing alloy electrode (electrode of the present invention) after 50,000 hours, and (c) shows 50,000. It is a figure which shows the state of the nickel electrode (conventional electrode) after time.

Referring to FIG. 3, when the X-ray photographs of the electrodes of each state are compared, after 50,000 hours have passed in FIG. 3A, which is the first electrode state, molybdenum is contained according to an embodiment of the present invention. Looking at the alloy electrode, as shown in (b) of Figure 3, there is only a slight sputtering trace on the bottom surface and side, and maintains a similar state to the original electrode state, the conventional nickel electrode of Figure 3 As shown in (c), it can be seen that holes A are generated on the bottom and side surfaces. This is because sputtering occurs on the surface of the electrode due to a long period of high voltage applied to the electrode, and the electrode is broken while the hardness thereof is weakened.

Experimental Example 2

Experimental Example 2 is a comparison of the metal structure of the surface of the CCFL electrode according to the prior art and the embodiment of the present invention, the results are shown in FIG. 4 is an enlarged photograph of a metal surface 500 times with an electron scanning microscope, (A) shows the surface structure of the molybdenum-containing nickel alloy electrode according to the present invention, (b) is the surface of a conventional nickel electrode It is an organization

Comparing the metal structure results of FIG. 4, the conventional nickel electrode (b) has a coarse structure due to heat during electrode welding. However, according to the present invention, molybdenum-containing alloy electrode (a) has a very high melting point. It can be seen that the nickel component is suppressed from coarsening due to the molybdenum component.

Experimental Example 3

Experimental Example 3 shows the change in hardness according to the heat treatment temperature in the state of the CCFL electrode according to the prior art and the embodiment of the present invention, the results are shown in the graph of FIG.

Referring to FIG. 5, the horizontal axis represents temperature (unit C) and the vertical axis represents hardness (unit hv). In addition, the graph (a) of Figure 5 shows an alloy electrode containing molybdenum according to the present invention, (b) the graph shows a conventional nickel electrode. Comparing the two graphs, considering that the temperature inside the electrode during the lamp discharge is 800 ℃ or more, it can be seen that the alloy electrode (A) has a higher hardness than the nickel electrode (b) even at 800 ℃ or more.

Experimental Example 4

Experimental Example 4 shows the tube voltage and the electrode part temperature in the CCFL lamp state according to the prior art and the embodiment of the present invention. The results are summarized in the following [Table 1].

As shown in Table 1, the tube voltage and electrode part temperature when the molybdenum-containing alloy electrode is applied to the lamp according to the first and second embodiments of the present invention are the conventional nickel electrode. It can be seen that the results are significantly lower than those of (Comparative Examples 1 and 2).

As a result, power consumption can be reduced by low tube voltage, and image problems on the liquid crystal module can be improved by low electrode temperature.

Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above-described embodiments, and various changes may be made by those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention. It may be changed and implemented.

As described above, the cold-cathode fluorescent lamp of the present invention has a low work function and adds molybdenum having excellent sputtering resistance and thermal conductivity to the nickel electrode, thereby lowering the heating temperature of the electrode portion of the lamp to improve LCD image problems. At the same time, the sputtering effect is suppressed to extend the life of the lamp, and the tube voltage can be lowered to improve the power consumption efficiency.

In addition, the present invention can be applied to improve the problems caused by heat generation from notebooks to large-sized television, and to reduce the power consumption, in particular for the purpose of reducing the number of lamps and equal luminance characteristics due to high current application. Application is possible.

Claims (3)

In the cold cathode fluorescent lamp in which the phosphor is coated on the inner wall of the sealed glass tube, and the electrode for discharge is disposed on both sides of the glass tube, The electrode is Made of nickel alloy containing molybdenum Molybdenum-added nickel alloy electrodes, which can reduce LCD heating problems by improving the temperature of lamps, improve the life of lamps by suppressing sputtering effects, and improve the power consumption efficiency by reducing tube voltage. Cold cathode fluorescent lamp using. The cold cathode fluorescent lamp using a molybdenum-containing nickel alloy electrode according to claim 1, wherein the molybdenum content added to the nickel metal used as the electrode is in a weight ratio of 3% to 15%. The method of claim 1, wherein the electrode Cold cathode fluorescent lamp using a nickel alloy electrode with molybdenum, characterized in that the lead electrode is a cup-shaped electrode connected.

Images