KR20070003069A - Lamp and backlight unit using the same - Google Patents

Abstract

A lamp and a backlight unit using the same are provided to reduce the abrasion of an electrode part of the lamp, thereby extending the lifetime of the lamp, by forming the electrode part of a first electrode formed within a lamp tube and a second electrode wrapping either end of the lamp tube to disperse the collision regions of electrons. A lamp tube(61) contains plasma and inactive gas therein. An inside wall of the lamp tube is coated with a fluorescent substance. A first electrode(71) is positioned at either end of the lamp tube, and formed within the lamp tube. A second electrode(72) is positioned at either end of the lamp tube, and has a cap shape for wrapping the lamp tube. The first electrode and the second electrode are electrically connected to each other. An electric power(66) is configured to apply voltage to the first and second electrodes to generate discharge in the lamp. A terminal(64) electrically connects between the electric power and the electrodes.

Description

Lamp and backlight unit using the same {LAMP AND BACKLIGHT UNIT USING THE SAME}

1 is a view schematically showing the structure of a conventional lamp.

2 is a diagram for explaining the cause of sputtering in an electrode.

3a to 3b show a lamp according to the invention;

4 is a diagram illustrating that sputtering is dispersed in an electrode according to the present invention.

5 is a view showing a liquid crystal display module using a lamp according to the present invention.

<Description of Symbols for Main Parts of Drawings>

11, 61: lamp tube 14, 64: terminal

12, 71, 72: electrode 16, 66: electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp used as a light source, and more particularly, to a lamp having a long life by reducing wear of an electrode and a backlight unit of a liquid crystal display module using the same.

In general, liquid crystal displays (hereinafter referred to as "LCDs") have tended to be increasingly wider in application due to features such as light weight, thinness, and low power consumption. According to this trend, LCDs are used for office automation equipment, audio / video equipment, and the like. On the other hand, the LCD is controlled to display the desired image on the screen by adjusting the transmission amount of the light beam according to the image signal applied to the plurality of control switches arranged in a matrix form.

Since the LCD is not a self-luminous display device, a light source such as a back light is required. There are two kinds of LCD backlights, a direct type method and an edge type method. The direct type places several fluorescent lamps on the plane. A diffusion plate is installed between the fluorescent lamp and the liquid crystal panel to maintain a constant space between the liquid crystal panel and the diffusion plate. In the light guide plate method, a fluorescent lamp is provided outside the flat plate, and light is incident from the fluorescent lamp onto the entire surface of the liquid crystal panel using a transparent light guide plate.

The lamp included in the backlight unit includes a lamp tube having a cylindrical shape, and a phosphor is coated on an inner wall surface of the lamp tube. Then, a discharge medium is injected into the discharge space inside the lamp tube, and electrodes are generally provided at both ends of the lamp tube.

1 is a view showing a general lamp and the driving circuit of the lamp.

Referring to Figure 1, the lamp is formed at both ends of the lamp tube 11, the electrodes 12 are divided into a cathode and an anode, respectively. Phosphors are applied to the inner wall surface of the lamp tube 11, and an inert gas such as mercury and argon is injected into the inner space. The power source 18 applies a driving voltage to the electrodes 12 formed at both ends thereof, which may cause discharge. To this end, a conductive wire 15 is connected between the electrodes 12 formed at both ends of the lamp and the power supply 18, and the conductive wire 15 and the electrodes 12 at both ends are electrically connected through the terminal 14. .

The light emission principle of the lamp is to use an inert gas discharge in the lamp tube 11. In other words, when a voltage is applied to the electrodes 12 in the power source 18, the electrons and cations in the lamp tube 11 accelerate to the place where the voltage of opposite polarity is applied and in this process collide with the electrons. Inert gases are excited and ionized. The excited inert gases generate ultraviolet radiation back to the ground state. The ultraviolet rays excite the phosphor coated on the inner wall of the lamp tube, and the phosphor returns to the ground state and emits visible light.

At this time, the electrons that accelerate acceleration collide with the inert gas, and other electrons are attracted to the electric field and collide with the electrode as shown in FIG. 2. As such, when electrons collide with the electrode, sputtering occurs and wear occurs on the surface of the electrode, which in turn shortens the life of the electrode.

Accordingly, it is an object of the present invention to provide a lamp, a backlight unit and a liquid crystal display module using the same to extend the life of the lamp.

In order to achieve the above object, the lamp according to the present invention includes a lamp tube including a plasma and an inert gas and the phosphor is coated on the inner wall; First electrodes positioned at both ends of the lamp tube and formed in the lamp tube; Located at both ends of the lamp tube and provided with a cap-shaped second electrode surrounding the lamp tube.

The first and second electrodes are electrically connected.

Other objects and features of the present invention in addition to the above object will be 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. 3A to 5.

3a shows a lamp according to the invention and 3b shows a cross section of the lamp.

3A and 3B, the lamp according to the present invention includes a lamp tube 61 including an inert gas and electrodes formed at both ends of the lamp tube 61. The electrode receives the voltage through the conductive wire connected to the power source 66 through the terminal 64 electrically connected.

The electrode for this purpose includes a first electrode 71 formed in the lamp tube 61 and a cap-shaped second electrode 72 surrounding the end of the lamp tube.

The light emission principle of the lamp according to the present invention is as follows. When a predetermined driving voltage is applied from the power source 66, electrons and cations in the plasma ion state in the lamp tube 61 move toward the place where the voltage of the opposite polarity is applied. At this time, some of the electrons in the acceleration motion collide with the inert gas, and the inert gas collided with the electrons is excited and ionized by the energy of the impact amount. The excited volatile gas releases the remaining energy in the form of ultraviolet rays, returning to the low energy base state. The emitted ultraviolet rays excite the phosphor coated on the inner wall of the lamp tube 61, and the phosphor emits visible light while returning to the ground state.

At this time, among the electrons accelerated by the voltage applied to the electrode, the electrons that do not collide with the inert gas are attracted to the electric field and eventually collide with the electrode. Conventionally, since the electrode is formed on the inner wall of the phosphor and the area of the electrode is small, the area of the electrode where electrons collide is also limited. However, in the lamp according to the present invention, as shown in FIG. 4, the electrode is composed of a first electrode 71 formed in the lamp tube 61 and a second electrode 72 surrounding the end of the lamp tube 61, so that electrons collide with each other. The area is also wider. That is, the wear of the electrode was severe because electrons collide with only the electrode portion formed in the lamp tube 61 to cause sputtering. However, in the present invention, wear of the electrode can be reduced because the area where the electrons collide is dispersed. As a result, the lifetime of the electrode is increased, that is, the lifetime of the lamp is increased.

5 is a view showing a liquid crystal display module using such a lamp.

Referring to FIG. 5, a liquid crystal display module according to the present invention is arranged side by side to generate a plurality of lamps 112, a lamp housing 110 to accommodate a plurality of lamps 112, a lamp housing 110. A diffusion plate 116 covering the opening of the ()), an optical film 118 sequentially stacked on the diffusion plate 116, and a liquid crystal panel 106 disposed on the optical film 118.

The liquid crystal panel 106 includes a spacer (not shown) for injecting liquid crystal between the upper substrate 103 and the lower substrate 105 to maintain a constant gap between the upper substrate 103 and the lower substrate 105. . The upper substrate 103 of the liquid crystal panel 106 is formed with a color filter, a common electrode, a black matrix, and the like, which are not shown. In addition, signal lines such as data lines and gate lines (not shown) are formed on the lower substrate 105 of the liquid crystal panel 106, and thin film transistors are formed at intersections of the data lines and the gate lines. The thin film transistor switches a data signal to be transmitted from the data line toward the liquid crystal cell in response to a scan signal (gate pulse) from the gate line. The pixel electrode is formed in the pixel region between the data line and the gate line. In addition, one side of the lower substrate 5 is formed with a pad region for connecting data lines and gate lines, respectively, and in this pad region, a tape in which a driver integrated circuit for applying a driving signal to the thin film transistor is mounted. A carrier package is attached. The tape carrier package supplies data signals and scan signals to the data lines and the gate lines from the driver integrated circuit, respectively.

The upper polarizing sheet (not shown) is attached to the upper substrate 103 of the liquid crystal panel 106, and the lower polarizing sheet (not shown) is attached to the rear surface of the lower substrate 105. At this time, the upper and lower polarizing sheets serve to extend the viewing angle of the image displayed by the liquid crystal cell matrix.

Each of the plurality of lamps 112 includes a glass tube, inert gases inside the glass tube, and a cathode and an anode installed at both ends of the glass tube. Inert gas is filled in the glass tube, and phosphor is coated on the inner wall of the glass tube.

Each of the plurality of lamps 112, when an alternating voltage from an inverter (not shown) is applied to the anode and the cathode, electrons are emitted from the cathode and collide with the inert gases inside the glass tube to exponentially increase the amount of electrons. do. As the electric current flows inside the glass tube by the increased electrons, energy is generated as the inert gas (Ar, Ne) is excited by the electrons, and the energy is emitted while the energy excites mercury. This ultraviolet light impinges on the luminescent phosphor applied to the inner wall of the glass tube to emit visible light.

The lamp housing 110 is made of aluminum, and prevents light leakage of visible light emitted from each of the plurality of lamps 112, and the front, that is, the diffuser plate of visible light traveling to the side and the back of the plurality of lamps 112. Reflecting toward 116 improves the efficiency of light generated in the lamps 112.

The diffuser plate 116 allows light emitted from the plurality of lamps 112 to propagate toward the liquid crystal panel 106, and allows incident light at a wide range of angles. Such a diffusion plate 116 uses a coating of a light diffusion member on both sides of a film made of a transparent resin.

The optical film 118 improves the efficiency of light emitted from the diffuser plate 116 to irradiate the liquid crystal panel 106.

As described above, the lamp according to the present invention can reduce the wear of the electrode to extend the life.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical 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 (5)

A lamp tube including a plasma and an inert gas and having a phosphor coated on an inner wall thereof; First electrodes positioned at both ends of the lamp tube and formed in the lamp tube; Lamps positioned on both ends of the lamp tube and having a cap-shaped second electrode surrounding the lamp tube. The method of claim 1, And the first and second electrodes are electrically connected. The method of claim 2, A power source for applying a voltage at which the discharge may occur in the lamp to the first and second electrodes; And a terminal for electrically connecting the power supply and the first and second electrodes. The method of claim 1, A lamp housing for accommodating the lamps, preventing light leakage from visible light emitted from each of the lamps, and traveling the visible light toward the display surface; A diffusion plate covering the opening of the lamp housing and injecting light emitted from the lamp toward the display surface at a wide range of angles; The backlight unit of the liquid crystal display module further comprises an optical film which is sequentially laminated on the diffusion plate to improve the efficiency of light. The method of claim 4, wherein An upper substrate on which a common electrode is formed; A lower substrate on which signal lines such as data lines and gate lines are formed, and thin film transistors are formed at intersections of the data lines and gate lines; And a liquid crystal panel including liquid crystal between the upper substrate and the lower substrate.

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