KR20100103055A - External electrode fluorescent lamp and liquid crystal display device module including the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display module using an external electrode fluorescent lamp as a light source.

A feature of the present invention is to form the external electrode of the external electrode fluorescent lamp with conductive silicon including a high dielectric layer. As a result, friction noise is not generated between the lamp fixing part of the metallic material and the external electrode, and temporarily darkens the image corresponding to the external electrode part during initial operation of the liquid crystal display, thereby degrading the screen quality of the liquid crystal display. It can prevent the problem that was brought.

In addition, the external electrode fluorescent lamp further includes a high dielectric layer to have a large capacitance, thereby lowering the driving voltage of the external electrode fluorescent lamp and improving the ozone characteristics of the external electrode fluorescent lamp. In addition, as the amount of electrons emitted from the external electrode increases, the amount of light generated by the external electrode fluorescent lamp increases, thereby increasing luminance. In addition, the size of the outer bezel, which is a non-light emitting area, can be reduced, as well as the effective light emitting area of the external electrode fluorescent lamp can be relatively extended, and at the same time, the service life is extended.

Description

External electrode fluorescent lamp and liquid crystal display device module including the same}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display module using an external electrode fluorescent lamp as a light source.

In line with the recent information age, the display field has also been rapidly developed, and a liquid crystal display device (FPD) is a flat panel display device (FPD) having advantages of thinning, light weight, and low power consumption. LCD, plasma display panel device (PDP), electroluminescence display device (ELD), field emission display device (FED), etc. : It is rapidly replacing CRT.

Among them, liquid crystal display devices are used most actively in the field of notebooks, monitors, TVs, etc. because of their excellent contrast ratio and high contrast ratio. Liquid crystal display devices are devices that do not have their own light emitting elements. It requires a light source.

As a result, a backlight unit having a lamp is provided on the rear side to irradiate light toward the front of the liquid crystal panel, thereby realizing an image of identifiable luminance.

On the other hand, the general backlight unit is divided into an edge type (edge type) and a direct type (direct type) according to the arrangement of the lamp, the edge type has a structure in which one or a pair of lamps are disposed on one side of the light guide plate, Two or two pairs of lamps have a structure in which both sides of the light guide plate are arranged, and the direct type has a structure in which several lamps are arranged under the optical sheet.

1 is a cross-sectional view of a liquid crystal display using a general direct type backlight unit.

As shown in the drawing, a general liquid crystal display device module includes a liquid crystal panel 10 including first and second substrates 12 and 14 and a backlight unit 20 behind the liquid crystal panel 10. The top cover 40 covering the front edge of the liquid crystal panel 10 and the cover bottom 50 covering the back surface of the backlight unit 20 in the state in which the support main 30 is wrapped are respectively coupled in front and rear to mediate the support main 30. Are integrated into.

The backlight unit 20 includes a reflector plate 22, and a plurality of lamps 24 are arranged side by side on an upper surface thereof, and a plurality of optical sheets 26 are interposed therebetween.

In this case, a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (EEFL), a light emitting diode (LED), or the like is used as the lamp 24.

Nowadays, the trend is to use external electrode fluorescent lamps that can ensure long life and light weight while ensuring high brightness and high efficiency of large display displays.

Therefore, the external electrode fluorescent lamp 24 is configured with an external electrode (not shown) on the outer surface of both ends of the glass tube, and the plurality of external electrode fluorescent lamps 24 are arranged side by side at a predetermined interval on the reflecting plate 22. .

In addition, the external electrode fluorescent lamp 24 is connected to an external electrode (not shown) by applying a voltage by a common electrode (not shown) to simultaneously apply an external voltage to the plurality of lamps 24.

FIG. 2 is a perspective view schematically illustrating an external electrode fluorescent lamp and a common electrode applying a voltage to the external electrode fluorescent lamp.

As shown, the external electrode fluorescent lamp 24 is formed so that the external electrode 24b surrounds the outer surface of both ends of the glass tube 24a, and the external electrode 24b is in contact with the external electrode 24b of the external electrode fluorescent lamp 24. The common electrode 60 for applying a voltage to the fluorescent lamp 24 is configured.

Here, the external electrode 24b of the external electrode fluorescent lamp 24 is made of a conductive metal material such as aluminum (Al), silver (Ag), copper (Cu), etc., which have a small electrical resistivity, and both ends of the glass tube 24a are predetermined. Form to wrap around.

The common electrode 60 includes first and second common electrode lines 61a and 61b and a plurality of lamp fixing parts 63 connected to the first and second common electrode lines 61a and 61b.

At this time, the lamp fixing portion 63 is to fix the external electrode fluorescent lamp 24 directly.

In addition, the common electrode 60 may be disposed at an outer end of the second common electrode line 61b on which one end of the external electrode fluorescent lamp 24 is seated in order to prevent left and right horizontal flow of the external electrode fluorescent lamp 24. It further includes a stopper 65 formed vertically upward.

Therefore, the plurality of external electrode fluorescent lamps 24 are fixed and supported at both ends by the lamp fixing portion 63 of each common electrode 60 formed on one side and the other side of the liquid crystal display, and the external electrode fluorescent lamp 24 The voltage for driving is applied.

Meanwhile, the external electrode fluorescent lamp 24 and the common electrode 60 are disposed between the external electrode fluorescent lamp 24 and the lamp fixing part 63 of the common electrode 60 for the convenience of fastening the external electrode fluorescent lamp 24. It should be designed to have a predetermined gap.

However, a predetermined gap between the lamp fixing portion 63 and the external electrode fluorescent lamp 24 causes the force of the lamp fixing portion 63 to fix the external electrode fluorescent lamp 24 is weak, which is an external electrode fluorescent lamp. In the process of receiving voltage by the common electrode 60, the external electrode fluorescent lamp 24 is formed by an electric field generated between the common electrode 60 and the external electrode 24b of the external electrode fluorescent lamp 24. ) Will cause tremor.

Therefore, friction occurs between the external electrode fluorescent lamp 24 and the lamp fixing part 63, and noise is generated by such friction.

This causes a great inconvenience for the user during actual driving.

In addition, when the external electrode fluorescent lamp 24 is driven, the temperature of the external electrode 24b made of a metal material is increased, which means that the mercury inside the external electrode fluorescent lamp 24 is relatively lower than that of the external electrode 24b. This causes the phenomenon that the external electrode fluorescent lamp 24 having a temperature is driven to the center portion.

As a result, temporary darkness occurs in an image corresponding to the external electrode 24b portion of the external electrode fluorescent lamp 24 which is temporarily deficient in mercury during the initial driving of the liquid crystal display.

This results in deterioration of the screen quality of the liquid crystal display.

The present invention has been made to solve the above problems, and a first object of the present invention is to reduce friction noise generated between the external electrode fluorescent lamp and the holder for fixing the external electrode fluorescent lamp.

In addition, the second object of the present invention is to solve the problem of deterioration of the screen quality of the liquid crystal display by temporarily darkening an image corresponding to the external electrode part during the initial driving of the liquid crystal display.

In order to achieve the object as described above, the present invention comprises a glass tube filled with an inert gas; First and second external electrodes formed on both ends of the glass tube and made of conductive silicon; It includes a fluorescent material formed on the inner surface of the glass tube, and provides an external electrode fluorescent lamp further comprising a high dielectric layer between the glass tube and the first and second external electrodes.

The high dielectric layer is made of ceramic or silicon having a larger dielectric constant than that of the glass tube, and the first and second external electrodes have a hexahedral shape through which the glass tube is inserted.

In addition, a protective layer is further formed between the inner surface of the glass tube and the fluorescent material.

And, the present invention is covered covertum; A reflection plate mounted on the cover bottom; A fluorescent lamp positioned above the reflecting plate and including an external electrode made of conductive silicon on both ends of the glass tube; A plurality of optical sheets positioned on the fluorescent lamp; A liquid crystal panel positioned on the plurality of optical sheets; A support main covering an edge of the liquid crystal panel and the plurality of optical sheets; A liquid crystal display module including a top cover covering a front edge of the liquid crystal panel and further comprising a high dielectric layer between the glass tube and the external electrode.

The high-k dielectric layer is made of ceramic or silicon having a higher dielectric constant than that of the glass tube, and further includes a common electrode simultaneously connecting the external electrodes to simultaneously apply an external voltage to a plurality of fluorescent lamps.

Here, the common electrode is composed of a plurality of holders having a predetermined interval in the longitudinal direction of the first and second power supply line and the first and second power supply line, the external electrode is a glass tube The common electrode includes a plate-shaped power supply line and a plurality of holders connected to the power supply line and spaced apart from each other in a longitudinal direction thereof.

In addition, a fitting hole is formed in a second surface of the external electrode corresponding to the plurality of holders.

As described above, according to the present invention by forming the external electrode of the external electrode fluorescent lamp with a conductive silicon containing a high dielectric layer, thereby, no friction noise is generated between the lamp fixing of the metallic material and the external electrode, Temporarily darkening occurs in an image corresponding to the external electrode part temporarily during initial driving of the liquid crystal display device, thereby preventing the problem of deterioration of the screen quality of the liquid crystal display device.

In addition, since the external electrode fluorescent lamp has a large capacitance by further including a high dielectric layer, the driving voltage of the external electrode fluorescent lamp can be lowered, and the ozone characteristic of the external electrode fluorescent lamp can be improved.

In addition, since the amount of electrons emitted from the external electrode increases, the amount of light generated by the external electrode fluorescent lamp increases, thereby increasing luminance. In addition, the size of the outer bezel, which is a non-light emitting area, can be reduced, as well as the effective light emitting area of the external electrode fluorescent lamp can be relatively extended, and at the same time, the service life is also extended.

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

3 is an exploded perspective view schematically illustrating a liquid crystal display module according to an exemplary embodiment of the present invention.

As illustrated, the liquid crystal display module includes a liquid crystal panel 110, a backlight unit 120, a support main 130, a cover bottom 150, and a top cover 140.

First, the liquid crystal panel 110 plays a key role in image expression, and includes the first and second substrates 112 and 114 bonded to each other with the liquid crystal layer interposed therebetween.

In this case, although it is not clearly shown in the drawings under the premise of an active matrix method, a plurality of gate lines and data lines intersect on the inner surface of the first substrate 112, which is commonly referred to as a lower substrate or an array substrate, and a pixel is defined. Thin film transistors (TFTs) are provided at each intersection to be connected one-to-one with the transparent pixel electrodes formed in each pixel.

In addition, an inner surface of the second substrate 114 called an upper substrate or a color filter substrate includes, for example, a color filter of R, G, and B colors, each of which includes a gate line, a data line, A black matrix for covering non-display elements such as a thin film transistor is provided. In addition, a transparent common electrode covering them is provided.

In addition, the printed circuit board 116 is connected through at least one edge of the liquid crystal panel 110 through a connection member 118 such as a flexible circuit board, and thus the side surface or cover bottom 150 of the support main 130 is modularized. ) It is flipped to the back and adhered.

Accordingly, in the liquid crystal panel 110 having the above-described structure, when the thin film transistor selected for each gate line is turned on by the on / off signal transmitted through the scan, the signal voltage is transferred to the corresponding pixel electrode through the data line. The arrangement direction of the liquid crystal molecules is changed by the electric field between the electrode and the common electrode, indicating a difference in transmittance.

In this case, polarizing plates 119a and 119b for selectively transmitting only specific polarized light are attached to outer surfaces of the first and second substrates 112 and 114.

In addition, although not clearly shown in the drawings, the upper and lower alignment layers for determining the initial molecular alignment direction of the liquid crystal are interposed between the two substrates 112 and 114 of the liquid crystal panel 110 and the liquid crystal layer, and filled therebetween. Seal patterns are formed along edges of both substrates 112 and 114 to prevent leakage of the liquid crystal layer.

The backlight unit 120 is provided to supply light from the rear surface of the liquid crystal panel 110 so that the difference in transmittance of the liquid crystal panel 110 is expressed to the outside.

The backlight unit 120 includes a reflector plate 122, a plurality of lamps 200, and a plurality of optical sheets 126. The plurality of lamps 200 are arranged side by side on the reflector plate 122, and these lamps are arranged side by side. A plurality of optical sheets 126 are positioned above the 200.

In this case, the lamp 200 used as the light source of the backlight unit 120 is an external electrode fluorescent lamp having external electrodes formed on both outer surfaces of the glass tube. Such external electrode fluorescent lamps 200 may be provided on the reflecting plate 122. Side by side with a predetermined interval, the external electrodes are collectively connected, the voltage is applied by the common electrode 160 to apply an external voltage to the plurality of external electrode fluorescent lamp 200 at the same time.

In addition, a pair of side supports 170 for fixing / supporting the plurality of external electrode fluorescent lamps 200 and the common electrode 160 are provided and fastened to the cover bottom 150.

In addition to fixing the common electrode 160 and the external electrode fluorescent lamp 200, the side support 170 serves to make the interval between the external electrode fluorescent lamp 200 and the plurality of optical sheets 126 constant. do.

Here, the reflector plate 122 is positioned on the rear surface of the plurality of external electrode fluorescent lamps 200 to reflect the light emitted from the rear surface of the external electrode fluorescent lamp 200 toward the liquid crystal panel 110 to improve the brightness of the light.

In addition, the plurality of optical sheets 126 disposed to be spaced apart from the external electrode fluorescent lamp 200 by a predetermined distance may include a diffusion sheet and at least one light collecting sheet.

Therefore, the light emitted from the plurality of external electrode fluorescent lamps 200 is processed into a uniform high quality while passing through the optical sheet 126 and then incident to the liquid crystal panel 110, by using the liquid crystal panel 110 Finally, a high brightness image can be displayed.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the top cover 140, the support main 130, and the cover bottom 150, and the top cover 140 is formed on the top surface of the liquid crystal panel 110. A rectangular frame having a cross section bent in a shape of “a” so as to cover the side edge, and opens the front surface of the top cover 140 to display an image implemented in the liquid crystal panel 110.

In addition, a support frame 130 having a rectangular frame shape covering the edges of the liquid crystal panel 110 and the backlight unit 120 is provided, and the liquid crystal panel 110 and the backlight unit 120 are seated so that the entire structure of the liquid crystal display module. The cover cover 150 made of metal, which is the basis of the assembly, is composed of a bottom surface of a plate shape and side surfaces of which four edges are vertically bent upwards.

In addition, although not shown in the drawings, the LCD module according to the present invention is provided with a backlight driving circuit (not shown) for controlling the on / off of the external electrode fluorescent lamp 200, which is preferable. Preferably the cover bottom 150 is mounted to the back to minimize the overall size.

Meanwhile, in the process of simultaneously applying external voltages to the plurality of external electrode fluorescent lamps 200 through the common electrode 160, an electric field generated between the common electrode 160 and the external electrode fluorescent lamp 200 made of metal material. Vibration of the external electrode fluorescent lamp 200 is generated.

Thus, a friction sound is generated between the external electrode fluorescent lamp 200 and the common electrode 160 through the shaking of the external electrode fluorescent lamp 200, and the present invention can prevent the friction sound from occurring.

In addition, the mercury inside the external electrode fluorescent lamp 200 may be prevented from being concentrated to the center portion of the external electrode fluorescent lamp 200, thereby improving the screen quality of the liquid crystal display device, which is an external electrode fluorescent lamp 200. Can be made by forming the external electrode of the electrode) with a conductive silicon material.

This will be described in more detail with reference to FIG. 4 below.

FIG. 4 is a perspective view schematically illustrating a common electrode applying a voltage to the external electrode fluorescent lamp and the external electrode fluorescent lamp of FIG. 3.

As shown in the drawing, the external electrode fluorescent lamp 200 is an external electrode fluorescent lamp in which the external electrode 220 surrounds the outer surface of both ends of the glass tube 210. The inert gas or mercury (Hg) molecules mixed inside the glass tube 210 are mixed. Inert discharge gas (fill discharge gas) is made of, and the fluorescent material is coated on the inner wall of the glass tube (210).

In particular, the external electrode fluorescent lamp 200 of the present invention is characterized in that the external electrode 220 is made of conductive silicon. Electroconductive silicone can be obtained by mixing and shape | molding carbon particle in a suitable ratio with silicone rubber, and has flexible rubber elasticity.

The external electrode fluorescent lamp 200 is in contact with the external electrode 220 configured at both ends to receive an external voltage, and requires a separate means for stably fixing the reflective sheet (122 in FIG. 3). This is done through the common electrode 160.

In detail, the common electrode 160 includes a plurality of common electrodes 160 connected to the first and second common electrode lines 161a and 161b and the first and second common electrode lines 161a and 161b. It consists of a lamp fixing part 163.

The lamp fixing part 163 directly fixes the external electrode fluorescent lamp 200 in a shape in which a plurality of holders 163a and 163b spaced apart in one direction are integrally formed. The lamp fixing parts 163 are configured to be equal to the number of the external electrode fluorescent lamps 200 spaced apart in the longitudinal direction of the first and second common electrode lines 161a and 161b.

At this time, the lamp fixing part 163 is composed of a conductor to which a voltage can be applied through the first and second common electrode lines 161a and 161b, and is directly connected to and fixed to the lamp fixing part 163. Voltage may be applied to the external electrode 220 of the fluorescent lamp 200.

Accordingly, the plurality of external electrode fluorescent lamps 200 are fixed and supported at both ends by the lamp fixing portions 163 of the common electrodes 160 configured on one side and the other side of the liquid crystal display, and flow by external impact. It can be fixed stably so as not to be damaged.

In addition, the common electrode 160 may be disposed at an outer end of the second common electrode line 161b on which one end of the external electrode fluorescent lamp 200 is seated in order to prevent left and right horizontal flow of the external electrode fluorescent lamp 200. It further includes a stopper 165 formed vertically upward.

On the other hand, the external electrode fluorescent lamp 200 and the lamp fixing part 163, the lamp fixing part 163 is not completely wrapped around the external electrode fluorescent lamp 200 for reasons of fastening convenience of the external electrode fluorescent lamp 200. It is designed to have a predetermined gap so that only a part is in contact.

Therefore, in the process of receiving the voltage by the common electrode 160, the external electrode fluorescent lamp 200 is applied to an electric field generated between the common electrode 160 and the external electrode 220 of the external electrode fluorescent lamp 200. As a result, vibration of the external electrode fluorescent lamp 200 is generated.

At this time, even if the shaking of the external electrode fluorescent lamp 200 occurs, the external electrode 220 of the external electrode fluorescent lamp 200 is formed of a conductive silicone having a flexible rubber elasticity, thereby fixing a metal lamp ( The friction sound is not generated between the 163 and the external electrode 220 of the external electrode fluorescent lamp 200.

In addition, the external electrode 220 of the external electrode fluorescent lamp 200 is formed of conductive silicon, so that the temperature of the external electrode 220 does not increase as compared with the conventional external electrode 220 formed of a metallic material.

As a result, the temperature of the conventional external electrode 220 increases, so that the mercury inside the external electrode fluorescent lamp 200 has a relatively lower temperature than the external electrode 220 having a high temperature. 200) it is possible to prevent the phenomenon of being driven to the center portion.

Therefore, when the LCD is initially driven, the image corresponding to the external electrode 220 of the external electrode fluorescent lamp 200 which temporarily lacks mercury may be temporarily darkened, resulting in deterioration of the screen quality of the LCD. Can be prevented.

In addition, since the external electrode 220 is formed of conductive silicon, electrical characteristics of the external electrode fluorescent lamp 200 may be improved.

The external electrode 220 made of such conductive silicon may have various forms.

First Embodiment

5A is a perspective view schematically illustrating a structure of an external electrode fluorescent lamp according to a first embodiment of the present invention, and FIG. 5B is a cross-sectional view of FIG. 5A.

As shown, the external electrode fluorescent lamp 200 according to the first embodiment of the present invention is a glass tube 210 filled with an inert discharge gas (201) made of a mixed inert gas, mercury (Hg) molecules, etc. ) And first and second external electrodes 220a and 220b at both ends of the glass tube 210.

Here, a protective layer 203 is formed along the inner wall of the glass tube 210 to prevent intrusion of ions and impurities from the glass tube 210 into the inside, and a fluorescent material 205 is formed inside the protective layer 203. Is applied.

The first and second external electrodes 220a and 220b of the external electrode fluorescent lamp 200 of the present invention are formed to surround a predetermined portion of the glass tube 210, particularly, the first and second external electrodes 220a and 220b. ) Is made of conductive silicon.

Here, looking at the conductive silicon in more detail, the conductive silicon can be obtained by mixing and molding the carbon particles in a suitable proportion to the silicone rubber, and has a flexible rubber elasticity.

In addition, the conductive silicone has excellent properties such as heat resistance, cold resistance, conductivity, ozone resistance, etc., compared to the general organic rubber. Conductive silicone has excellent heat resistance compared to the organic rubber, and can be used semi-permanently at 150 ° C. with almost no change in properties. have.

In addition, the low temperature used system of the general organic rubber is -20 ℃ to -30 ℃, the conductive silicon can be used at a low temperature of -55 ℃ to -70 ℃, so the cold resistance is very excellent, the electrical characteristics of the conductive silicone temperature change It has a conductive characteristic that is not greatly influenced by it.

In addition, the conductive silicone is very excellent in ozone resistance, and ozone generated by corona discharge softens the organic organic rubber rapidly, but the conductive silicone is not affected at all.

Therefore, when voltage is applied to the first and second external electrodes 220a and 220b, the inert discharge gases 201 filled in the glass tube 210 collide with the electrons formed at the electrodes 220a and 220b. The excited electrons are converted into ultraviolet light as they return to a stable state.

As the ultraviolet rays collide with the fluorescent material 205 and scatter and emit visible light, the visible light passes through the protective layer 203 and the external electrode fluorescent lamp 200 emits light.

As such, by forming the external electrodes 220a and 220b with conductive silicon, even if the external electrode fluorescent lamp 200 is shaken, the lamp fixing part 163 of FIG. 4 and the external electrode fluorescent lamp 200 are formed. Friction noise is not generated between the external electrodes 220a and 220b.

In addition, since the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 are made of conductive silicon, the temperature of the external electrodes 220a and 220b is higher than that of the conventional external electrodes 220a and 220b made of metal. It will not increase.

As a result, the temperature of the conventional external electrode 220 increases, so that the mercury inside the external electrode fluorescent lamp 200 has a relatively lower temperature than the external electrode 220 having a high temperature. 200) it is possible to prevent the phenomenon of being driven to the center portion.

Accordingly, temporary darkening occurs in an image corresponding to the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 that is temporarily deficient in mercury during initial operation of the liquid crystal display, resulting in deterioration of the screen quality of the liquid crystal display. Problems that came can be prevented.

In addition, by forming the external electrodes 220a and 220b with conductive silicon, electrical characteristics of the external electrode fluorescent lamp 200 may be improved.

In more detail, the following table (1) shows an external electrode fluorescent lamp (24 of FIG. 2) including an external electrode (24b of FIG. 2) made of a conventional metal material and an external electrode made of conductive silicon of the present invention ( Experimental data comparing the tube voltages of the external electrode fluorescent lamps 200 including 220a and 220b.

Vs Is Vth Ith IL VL EEFL 1 1784Vrms 5.16 mA 1758 Vms 4.58 mA 7.50 mA 2109 Vrms EEFL 2 1772Vrms 5.62mA 1735 Vms 4.95 mA 7.50 mA 2052Vrms

Table (1)

(Vs: Start voltage of external electrode fluorescent lamp, Is: Start current of external electrode fluorescent lamp, Vth: Start voltage of external electrode fluorescent lamp, Ith: Start current of external electrode fluorescent lamp, VL: Start of external electrode fluorescent lamp Tube voltage, IL: Tube current of external electrode fluorescent lamp)

Here, EEFL 1 represents an external electrode fluorescent lamp (24 of FIG. 2) including an external electrode (24b of FIG. 2) made of a conventional metal material, EEFL 2 is a conductive silicon according to a first embodiment of the present invention The external electrode fluorescent lamp 200 including the external electrodes 220a and 220b may be formed.

As can be seen from Table (1), it can be seen that EEFL 2 has a lower starting voltage and lighting start voltage than EEFL 1, and EEFL 1 and EEFL 2 have the same tube current but EEFL2 has a lower tube voltage than EEFL 1. .

That is, by forming the external electrodes 220a and 220b with conductive silicon, the driving voltage required to flow a constant current of the external electrode fluorescent lamp 200 can be reduced.

In addition, by lowering the tube voltage of the external electrode fluorescent lamp 200, it is possible to improve the ozone characteristics of the external electrode fluorescent lamp 200.

In general, when the tube voltage of the external electrode fluorescent lamp 200 increases, the external electrodes 220a and 220b are exposed to the outside, and thus it is easy to generate ozone by generating oxygen and corona discharge in the air.

However, in the external electrode fluorescent lamp 200 of the present invention, since the conductive silicon has ozone resistance and the tube voltage can be lowered, ozone generation can be minimized.

In addition, while maintaining the same brightness as before, it is possible to reduce the length L of the external electrodes 220a and 220b, which are non-light-emitting regions, thereby reducing the size of the outer bezel of the non-light-emitting regions, as well as relatively external electrode fluorescence. The effective light emitting area B of the lamp 200 may be widened.

In other words, if the length L of the external electrodes 220a and 220b is reduced, the tube current is lowered and the luminance of the external electrode fluorescent lamp 200 is reduced.

However, since the external electrode fluorescent lamp 200 of the present invention can have the same tube current with a lower tube voltage than the conventional one, if the tube voltage is kept the same as before, the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 are used. Even if this length L is reduced, it can have the same tube current as before.

Therefore, even though the length L of the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 is reduced, the brightness of the same external electrode fluorescent lamp 200 can be maintained.

Second Embodiment

6A is a perspective view schematically illustrating a structure of an external electrode fluorescent lamp according to a second exemplary embodiment of the present invention, and FIG. 6B is a cross-sectional view of FIG. 6A.

In this case, in order to avoid duplicate description, the same reference numerals are given to the same parts that play the same role as the description of FIGS. 5A to 5B described above, and only the characteristic contents to be described above will be described.

As shown, the external electrode fluorescent lamp 200 according to the second embodiment of the present invention is a glass tube 210 filled with an inert discharge gas (201) made of a mixed inert gas, mercury (Hg) molecules, etc. ) And first and second external electrodes 220a and 220b at both ends of the glass tube 210.

Here, a protective layer 203 is formed along the inner wall of the glass tube 210 to prevent intrusion of ions and impurities from the glass tube 210 into the inside, and a fluorescent material 205 is formed inside the protective layer 203. Is applied.

The first and second external electrodes 220a and 220b of the external electrode fluorescent lamp 200 of the present invention are formed to surround a predetermined portion of the glass tube 210, particularly, the first and second external electrodes 220a and 220b. ) Is made of conductive silicon.

In particular, the external electrode fluorescent lamp 200 of the present invention is characterized in that it further comprises a high-k dielectric layer 230 between the first and second external electrodes 220a, 220b and the glass tube 210, and thus the present invention The external electrode fluorescent lamp 200 is to form a large capacitance (capacitance) corresponding to the high brightness as a backlight and to achieve a high efficiency with a long life.

Looking at this in more detail, if the external electrode fluorescent lamp 200 is defined by dividing the electrode portion consisting of the first and second external electrodes 220a and 220b at both ends and the light emitting portion B from which light is emitted, The electrons in the glass tube 210 and the first and second external electrodes 220a and 220b respectively form a capacitor by the entire layer 230.

Here, a capacitor is basically a structure in which two electrode plates are opposed to each other. When a positive current flows when the positive electrode plates are placed in parallel so as not to be in contact with each other, the positive electrode plate is positively and positively charged by electrons. It has the characteristic of being charged state with the electrode of-).

That is, when voltage is applied to the first and second external electrodes 220a and 220b, the high dielectric layer 230 of the electrode unit is formed inside the first and second external electrodes 220a and 220b and the glass tube 210. Electrons are positively and negatively charged so that the electrons inside the glass tube 210 and the first and second external electrodes 220a and 220b form a capacitor, respectively.

At this time, the capacitance of the external electrode fluorescent lamp 200 is expressed by Equation (1) below.

q = CV, C = εA / d ......... (1)

q is the accumulated charge, V is the applied voltage, and C is a constant representing the degree of ability of the electrode to accumulate charge. It is called electrostatic capacity. In addition, A represents the area of the electrode, d represents the distance between the anode plates, and ε represents the permittivity.

Looking at equation (1) above, the capacitance C is proportional to the dielectric constant epsilon and the area A of the electrode and inversely proportional to the distance d between the two electrodes.

Therefore, in order to increase the capacitance C, the area of the external electrodes 220a and 220b should be increased or a dielectric having a large dielectric constant ε should be included. However, the area of the external electrodes 220a and 220b is determined by the outer bezel size. Limited by

Therefore, the present invention further includes a high-k dielectric layer 230 between the first and second external electrodes 220a and 220b and the glass tube 210 to thereby have a large capacitance C corresponding thereto.

In more detail, when the power is supplied to the first and second external electrodes 220a and 220b and the charges are discharged from the first and second external electrodes 220a and 220b, the opposite polarity is formed around the inner wall of the glass tube 210. Wall charges build up.

Accordingly, the present invention further includes a high dielectric layer 230 between the first and second external electrodes 220a and 220b and the glass tube 210, so that a greater amount of charge is charged by the high dielectric layer 230. Accordingly, a large amount of secondary electrons are generated in the glass tube 210.

Therefore, the external electrode fluorescent lamp 200 of the present invention has a higher capacitance C than the conventional external electrode fluorescent lamp 24 of FIG. 2.

In this case, the high dielectric layer 230 is made of ceramic, silicon, and the like, and the dielectric constant of the high dielectric layer 230 is preferably larger than that of the glass tube 210.

When the capacitance C is increased in this way, the driving voltage required to flow the same constant current as in the prior art is lowered.

In more detail, the following table (2) shows the external electrode fluorescent lamp (24 of FIG. 2) including the external electrode (24b of FIG. 2) made of a conventional metal material and the conductivity according to the first embodiment of the present invention. An external electrode fluorescent lamp 200 including external electrodes 220a and 220b made of silicon, and a high dielectric layer 230 and external electrodes 220a and 220b made of conductive silicon according to the second embodiment of the present invention. The experimental data is shown by comparing the tube voltage of the external electrode fluorescent lamp (200).

Vs Is Vth Ith IL VL EEFL 1 1784Vrms 5.16 mA 1758 Vms 4.58 mA 7.50 mA 2109 Vrms EEFL 2 1772Vrms 5.62mA 1735 Vms 4.95 mA 7.50 mA 2052Vrms EEFL 3 1760Vrms 5.68 mA 1723 Vms 4.98 mA 7.50 mA 2012Vrms

Table (2)

(Vs: Start voltage of external electrode fluorescent lamp, Is: Start current of external electrode fluorescent lamp, Vth: Start voltage of external electrode fluorescent lamp, Ith: Start current of external electrode fluorescent lamp, VL: Start of external electrode fluorescent lamp Tube voltage, IL: Tube current of external electrode fluorescent lamp)

Here, EEFL 1 represents an external electrode fluorescent lamp (24 of FIG. 2) including an external electrode (24b of FIG. 2) made of a conventional metal material, EEFL 2 is a conductive silicon according to a first embodiment of the present invention The external electrode fluorescent lamp 200 including the external electrodes 220a and 220b may be formed, and EEFL 2 may include the high dielectric layer 230 and the external electrodes 220a and 220b made of conductive silicon according to the second embodiment of the present invention. ) Represents an external electrode fluorescent lamp 200.

As can be seen from Table (2), it can be seen that EEFL 2 has a lower starting voltage and lighting start voltage than EEFL 1, and EEFL 1 and EEFL 2 have the same tube current, but EEFL2 has a lower tube voltage than EEFL 1. .

In addition, the EEFL 3 has a lower starting voltage and a start-up voltage than the EEFL 1 and 2, and it can be seen that the EEFL 3 has a lower tube voltage than the EEFL 2 having the same tube current.

That is, by forming the external electrodes 220a and 220b using the high dielectric layer 230 and the conductive silicon, the driving voltage required to flow a constant current of the external electrode fluorescent lamp 200 can be further lowered.

In addition, by lowering the tube voltage of the external electrode fluorescent lamp 200, it is possible to improve the ozone characteristics of the external electrode fluorescent lamp 200.

In general, when the tube voltage of the external electrode fluorescent lamp 200 increases, the external electrodes 220a and 220b are exposed to the outside, and thus it is easy to generate ozone by generating oxygen and corona discharge in the air. However, in the external electrode fluorescent lamp 200 of the present invention, since the conductive silicon has ozone resistance and the tube voltage can be lowered, ozone generation can be minimized.

In addition, as the amount of electrons emitted from the external electrodes 220a and 220b increases, electrons collide with the inert discharge gas 201 existing in the glass tube 210, thereby increasing the amount of ultraviolet rays emitted. do.

Therefore, the amount of ultraviolet light that collides with the fluorescent material 205 is large, and thus the amount of visible light emitted to the outside is also large. As a result, the amount of light generated by the external electrode fluorescent lamp 200 increases, resulting in high luminance.

In addition, if the capacitance C is increased, the same luminance as the conventional one may be maintained, but the length L of the external electrodes 220a and 220b, which are non-light emitting regions, may be reduced, thereby reducing the size of the outer bezel of the non-light emitting region. In addition, the effective light emitting area B of the external electrode fluorescent lamp 200 can be relatively widened.

In other words, if the length L of the external electrodes 220a and 220b is reduced, the tube current is lowered and the luminance of the external electrode fluorescent lamp 200 is reduced.

However, since the external electrode fluorescent lamp 200 of the present invention can have the same tube current with a lower tube voltage than the conventional one, if the tube voltage is kept the same as before, the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 are used. Even if this length L is reduced, it can have the same tube current as before.

Therefore, even though the length L of the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 is reduced, the brightness of the same external electrode fluorescent lamp 200 can be maintained.

In addition, when the capacitance C is increased, the life of the external electrode fluorescent lamp 200 can be extended, and the life of the external electrode fluorescent lamp 200 can be expressed as follows.

Equation (2) below is a formula for calculating the life of the external electrode fluorescent lamp 200.

D =

Expression (2)

Here, D is the life time of the external electrode fluorescent lamp 200,

Is the intensity of the current supplied to the external electrode fluorescent lamp 200,

Denotes the area of the electrodes 220a and 220b, and

Is a constant coefficient of the gas injected into the external electrode fluorescent lamp 200,

Is a pressure value of the buffer gas, and has a different value depending on the type or mixing ratio of the gas injected into the external electrode fluorescent lamp 200, where ?? represents a constant value.

Therefore, the area of the electrodes 220a and 220b (

) And the constant value (

) Is constant, the lifetime of the external electrode fluorescent lamp 200 is inversely proportional to the strength of the current, so having a large capacitance (C) can have the same tube current at a lower tube voltage than the conventional, the external electrode fluorescent lamp ( It can be seen that the life of the 200) is also extended.

As such, by forming the external electrodes 220a and 220b with conductive silicon, even if the external electrode fluorescent lamp 200 is shaken, the lamp fixing part 163 of the metallic material and the external electrode of the external electrode fluorescent lamp 200 ( There is no friction between 220).

In addition, since the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 are made of conductive silicon, the temperature of the external electrodes 220a and 220b is higher than that of the conventional external electrodes 220a and 220b made of metal. It will not increase.

As a result, the temperature of the external electrodes 220a and 220b made of a conventional metal is increased, so that mercury inside the external electrode fluorescent lamp 200 is relatively lower than that of the external electrodes 220a and 220b having a high temperature. It is possible to prevent the phenomenon of being driven to the center portion of the external electrode fluorescent lamp 200 having a temperature.

Accordingly, temporary darkening occurs in an image corresponding to the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 that is temporarily deficient in mercury during initial operation of the liquid crystal display, resulting in deterioration of the screen quality of the liquid crystal display. Problems that came can be prevented.

In addition, by forming a high-k dielectric layer 230 between the external electrode 220 made of conductive silicon and the glass tube 210 of the external electrode fluorescent lamp 200, the external electrode fluorescent lamp 200 has a large capacitance, The driving voltage of the external electrode fluorescent lamp 200 may be lowered and the ozone characteristic of the external electrode fluorescent lamp 200 may be improved. In addition, as the amount of electrons emitted from the external electrodes 220a and 220b increases, the amount of light generated by the external electrode fluorescent lamp 200 increases, thereby increasing luminance.

In addition, the size of the outer bezel, which is the non-light emitting area, can be reduced, as well as the effective light emitting area B of the external electrode fluorescent lamp 200 can be relatively extended, and at the same time, the service life is also extended.

Third Embodiment

7A to 7B are perspective views schematically illustrating an external electrode fluorescent lamp and a common electrode applying a voltage to the external electrode fluorescent lamp according to the third embodiment of the present invention.

In this case, in order to avoid redundant description, the same parts having the same role as the description of FIGS. 4, 5A through 5B, and 6A through 6B will be denoted by the same reference numerals, and only the characteristic contents to be described above will be described. .

As shown in the drawing, the external electrode fluorescent lamp 200 is an external electrode fluorescent lamp in which the external electrode 220 surrounds the outer surface of both ends of the glass tube 210. The inert gas or mercury (Hg) molecules mixed inside the glass tube 210 are mixed. Inert discharge gas (fill discharge gas) is made of, and the fluorescent material is coated on the inner wall of the glass tube (210).

In particular, the external electrode fluorescent lamp 200 of the present invention is characterized in that the external electrodes 220a and 220b are formed of a hexahedron with conductive silicon including the high dielectric layer 230.

That is, the overall shape of the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 has a hexahedral shape, and includes first and second surfaces 221a and 221b parallel to each other, and first and second surfaces 221a and 221. The first and second side surfaces 221c and 221d and the first and second side surfaces 221c and 221d which connect the edges of the 221b and include holes (not shown) into which the external electrode fluorescent lamp 200 is inserted. And third and fourth side surfaces 221e and 221f connecting the first and second surfaces 221a and 221b.

The external electrode fluorescent lamp 200 is in contact with the external electrodes 220a and 220b configured at both ends thereof to receive an external voltage, and requires a separate means for stably fixing the reflective sheet 122 of FIG. 3. This is done through the common electrode 160.

Here, the common electrode 160 will be described in detail. The common electrode 160 includes a common electrode line 161 and a plurality of lamp fixing parts 163 connected to the common electrode line 161.

The lamp fixing part 163 consists of a pair of holders 163a and 163b, and the external electrodes 220a and 220b are inserted into and fixed to the holders 163a and 163b of the lamp fixing part 163. The lamp fixing part 163 is spaced apart along the longitudinal direction of the common electrode line 161 and constitutes the number of external electrode fluorescent lamps 200.

At this time, although not shown, a fitting hole through which the pair of holders 163a and 163b of the lamp fixing part 163 may be fitted is formed on the second surface 221b of the external electrodes 220a and 220b.

The lamp fixing part 163 is formed of a conductor to which a voltage can be applied through the common electrode line 161, and the external electrode of the external electrode fluorescent lamp 200 which is directly fixed to the lamp fixing part 163. Voltages may be applied to 220a and 220b.

Accordingly, the plurality of external electrode fluorescent lamps 200 are fixed and supported at both ends by the lamp fixing portions 163 of the common electrodes 160 configured on one side and the other side of the liquid crystal display, and flow by external impact. It can be fixed stably so as not to be damaged.

As such, by forming the external electrodes 220a and 220b with conductive silicon, even if the external electrode fluorescent lamp 200 is shaken, the lamp fixing part 163 of the metallic material and the external electrode of the external electrode fluorescent lamp 200 ( There is no friction between 220).

In addition, since the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 are made of conductive silicon, the temperature of the external electrodes 220a and 220b is higher than that of the conventional external electrodes 220a and 220b made of metal. It will not increase.

As a result, the temperature of the external electrode parts 220a and 220b is increased, and the mercury inside the external electrode fluorescent lamp 200 has an external temperature having a relatively lower temperature than that of the external electrode parts 220a and 220b. The phenomenon of being driven to the center portion of the electrode fluorescent lamp 200 can be prevented.

Accordingly, temporary darkening occurs in an image corresponding to the external electrodes 220a and 220b of the external electrode fluorescent lamp 200 that temporarily lacks mercury during initial driving of the liquid crystal display, resulting in deterioration of the screen quality of the liquid crystal display. Problems that came can be prevented.

In addition, the high-electrode layer 230 is further formed between the external electrodes 220a and 220b made of conductive silicon and the glass tube 210 of the external electrode fluorescent lamp 200 so that the external electrode fluorescent lamp 200 has a large capacitance. As a result, the driving voltage of the external electrode fluorescent lamp 200 can be lowered, and the ozone characteristic of the external electrode fluorescent lamp 200 can be improved. In addition, as the amount of electrons emitted from the external electrodes 220a and 220b increases, the amount of light generated by the external electrode fluorescent lamp 200 increases, thereby increasing luminance.

In addition, the size of the outer bezel, which is the non-light emitting area, can be reduced, as well as the effective light emitting area B of the external electrode fluorescent lamp 200 can be relatively extended, and at the same time, the service life is also extended.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is a cross-sectional view of a liquid crystal display device using a general direct type backlight unit.

2 is a view schematically showing the appearance of a common electrode for applying a voltage to the external electrode fluorescent lamp and the external electrode fluorescent lamp.

3 is an exploded perspective view schematically showing a liquid crystal display module according to an embodiment of the present invention.

4 is a perspective view schematically illustrating a common electrode applying voltage to the external electrode fluorescent lamp and the external electrode fluorescent lamp of FIG. 3;

5A is a perspective view schematically showing the structure of an external electrode fluorescent lamp according to a first embodiment of the present invention;

5B is a cross-sectional view of FIG. 5A.

6A is a perspective view schematically showing the structure of an external electrode fluorescent lamp according to a second embodiment of the present invention;

6B is a cross-sectional view of FIG. 6A.

7A to 7B are perspective views schematically illustrating an external electrode fluorescent lamp and a common electrode applying a voltage to the external electrode fluorescent lamp according to the third embodiment of the present invention.

Claims (11)

A glass tube filled with an inert gas; First and second external electrodes formed on both ends of the glass tube and made of conductive silicon; Fluorescent material formed on the inner surface of the glass tube And an external electrode fluorescent lamp further comprising a high dielectric layer between the glass tube and the first and second external electrodes. The method of claim 1, The high dielectric layer is an external electrode fluorescent lamp made of ceramic or silicon having a large dielectric constant relative to the dielectric constant of the glass tube. The method of claim 1, The first and second external electrodes of the external electrode fluorescent lamp having a hexahedral shape through which the glass tube is inserted. The method of claim 1, An external electrode fluorescent lamp, characterized in that a protective layer is further formed between the inner surface of the glass tube and the fluorescent material. Covertum; A reflection plate mounted on the cover bottom; A fluorescent lamp positioned above the reflecting plate and including an external electrode made of conductive silicon on both ends of the glass tube; A plurality of optical sheets positioned on the fluorescent lamp; A liquid crystal panel positioned on the plurality of optical sheets; A support main covering an edge of the liquid crystal panel and the plurality of optical sheets; Top cover covering the front edge of the liquid crystal panel And a high dielectric layer between the glass tube and the external electrode. The method of claim 5, And the high dielectric layer is made of ceramic or silicon having a higher dielectric constant than that of the glass tube. The method of claim 6, And a common electrode connecting the external electrodes collectively to apply an external voltage to a plurality of fluorescent lamps simultaneously. The method of claim 7, wherein The common electrode includes a first and a second power supply line, and a plurality of holders having a predetermined interval along the longitudinal direction of the first and second power supply line. The method of claim 7, wherein And the external electrode has a hexahedral shape through which the glass tube is inserted. The method of claim 9, The common electrode is a liquid crystal display module comprising a plate-shaped power supply line, and a plurality of holders connected to the power supply line and spaced apart from each other in a longitudinal direction thereof. The method of claim 10, And a fitting hole formed in a second surface of the external electrode corresponding to the plurality of holders.

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