KR20080001227A - Apparatus for fixing a lamp of the back-light - Google Patents

Abstract

A device for fixing a lamp of a backlight unit is provided to minimize a non-luminescent area caused by an external electrode and optimize a length of an external electrode lamp by forming sub electrodes, capable of supporting a function of the external electrode of the external electrode lamp, in a common electrode. A holder(51) surrounds an external electrode(31) of an external electrode lamp mounted on a backlight unit, and transfers common voltage to the external electrode. In a common electrode, the holders of which the number is consistent with the number of the external electrode lamps mounted on the backlight unit are disposed at intervals of the external electrode lamp. The common electrode receives the common voltage and transfers the received common voltage to the holder. Sub electrodes(53) are protruded from the common electrode in a length direction of the external electrode lamps fixed by the holder.

Description

Lamp fixture of backlight unit {APPARATUS FOR FIXING A LAMP OF THE BACK-LIGHT}

1 is a configuration diagram of an embodiment of a general direct type backlight unit.

Figure 2 is an external configuration of one embodiment of a typical external electrode lamp (EEFL).

Figure 3 is a plan view of one embodiment showing a lamp fixing device of a direct type backlight unit using a conventional EEFL.

Figure 4 is another cross-sectional view of the lamp fixing device of the direct type backlight unit using a conventional EEFL.

5 is an exemplary view showing a dark line generated in a conventional direct type backlight unit.

6 is a plan view showing a state in which the lamp fixing device of the backlight unit according to the present invention is disposed on the cover bottom.

7 is a front view illustrating a state in which a lamp fixing device of the backlight unit illustrated in FIG. 6 is disposed at a cover bottom.

8 is a side view illustrating a state in which a lamp fixing device of the backlight unit illustrated in FIG. 6 is disposed at a cover bottom.

9 is a chart showing the relationship between the tube voltage and the brightness of the external electrode lamp with or without the auxiliary electrode.

<Explanation of symbols for main parts of the drawings>

30: external electrode lamp 31: external electrode

32: glass tube (lamp) 51: holder

52: common electrode 53: auxiliary electrode

54: common electrode support

The present invention relates to a lamp fixing device of a backlight unit using an external electrode lamp, and more particularly to a lamp fixing device in which an auxiliary electrode is formed.

In recent years, as the society enters the information age, the display industry that processes and displays a large amount of information has been rapidly developed.

As a result, a liquid crystal display device (LCD device) is being developed that can meet various demands of the user, such as thinning, light weight, and low power consumption, and replaces a conventional cathode-ray tube (CRT). It is attracting attention as the next generation display device.

In general, a liquid crystal display may be classified into a liquid crystal panel displaying an image largely seen by a user, and a back light unit for increasing the brightness of the image.

The liquid crystal panel has a structure in which a lower substrate and an upper substrate on which one electric field generating electrode is formed are arranged to face each other, and then a liquid crystal layer is interposed therebetween. In this case, the liquid crystal has a thin and long molecular structure, optical anisotropy having an orientation in the array, and polarization property in which the array direction changes when an electric field is artificially applied. On the other hand, the liquid crystal panel changes the arrangement direction of the liquid crystal by applying an electric field to the liquid crystal interposed between the upper substrate, the lower substrate and the field generating electrodes provided on each of them, and expresses the image with the refractive index of the changed light. However, the brightness of the image implemented only by the liquid crystal panel is very low, making it difficult for the user to identify. Accordingly, a backlight unit including a plurality of light sources is provided on the back of the liquid crystal panel to supply light to the liquid crystal panel, thereby displaying an image that can be identified by the user.

Generally, the backlight unit may be classified into an edge type and a direct type according to the arrangement of the light sources. The edge type backlight unit may include a light source installed at one edge of the liquid crystal display, and a plurality of lights may be incident from the light source. Irradiates the liquid crystal display panel through an optical sheet of light, and the direct-type backlight unit unit arranges a plurality of light sources directly below the liquid crystal display device, and transmits light incident from the light sources through the diffusion plate and the plurality of optical sheets. Investigate the panel.

1 is a configuration diagram of an embodiment of a general direct type backlight unit.

That is, the general direct type backlight unit as shown in FIG. 1 includes a cover bottom 21 on a plate made of a metal or a synthetic resin material, and a white or silver metal material seated on a cover bottom. And a reflector 22 on a plate, a lamp 23 arranged in parallel on the reflecting plate, and an optical sheet portion 29 seated on the plurality of lamps. At this time, the inner surface of the cover bottom 21 is coated with a material (reflective plate) having a high optical reflectivity so that the light emitted backward from the lamp is reflected toward the front (to the liquid crystal panel side) to effectively use the luminous flux emitted from the lamp. Thereby increasing efficiency (efficiency expressed as the ratio of the luminous flux emitted from the light emitting surface to the luminous flux emitted from the lamp).

The optical sheet unit 29 includes a diffusion plate 24 seated on the vertical top of the lamp 23, a diffusion sheet 25 seated on the top of the diffusion plate, and a prism sheet 26 seated on the top of the diffusion sheet. And a reflective polarizing film (MOF) 27 having a multilayer structure seated on top of the prism sheet. At this time, the diffusion plate and the diffusion sheet is used to diffuse the direct light and the reflected light from the fluorescent lamp to the front to ensure a uniform brightness across the entire light emitting surface.

Meanwhile, a liquid crystal panel (not shown) manufactured through a separate process is mounted on the upper end of the optical sheet unit 29, and the liquid crystal panel is coupled to the direct type backlight unit through a top frame (not shown). As a result, the liquid crystal display device is completed.

In this case, since the general direct-backlit backlight unit illustrated in FIG. 1 may implement a high brightness by connecting a plurality of lamps in parallel, it is widely used as a backlight unit of a large screen liquid crystal panel as compared to an edge type backlight unit.

On the other hand, the lamp 23 used as a light source in the direct type backlight unit is a cold cathode fluorescent lamp (CCFL) (hereinafter, simply referred to as 'CCFL') or an external electrode lamp (EEFL: External Electrode Fluorescent Lamp) (Hereinafter, simply referred to as 'EEFL') is used. However, EEFL, which can be driven by connecting several lamps in parallel, is simpler in wiring and fixture assembly than in direct-type backlight unit using CCFL which connects inverter to each lamp. It is widely used because of the low number of people, equipment, and defective rate.

2 is a diagram illustrating an external configuration of a typical external electrode lamp (EEFL).

That is, as shown in FIG. 2, the external electrode lamp (EEFL) 30 is a transparent tube and is formed at both ends of the glass tube 32 and the glass tube coated with a phosphor on an inner wall thereof, and is supplied from an external source. It is configured to include two external electrodes 31 for receiving and transmitting to the glass tube.

The external electrode lamp (EEFL) 30 as described above applies a fluorescent material to the inner surface of the cylindrical electrodeless glass tube 32, injects and discharges a discharge gas therein, and then seals the external electrode 31 at both ends. In this case, a continuous high frequency voltage or a pulsed high frequency voltage is applied to the external electrode 31 to light it. At this time, the high frequency voltage applied to the pair of external electrodes 31 generates a discharge in the inner space of the glass tube fitted to the external electrode, and the ultraviolet rays generated by the discharge cause the fluorescent material applied to the inner surface of the glass tube 32 to emit light. The light generated by the discharge is emitted outside the glass tube 32, and the light is irradiated onto the irradiated object.

3 is a plan view showing an embodiment of a lamp fixing device of a direct type backlight unit using a conventional EEFL. In addition, Figure 4 is another cross-sectional view of the lamp fixing device of the conventional direct type backlight unit using the EEFL, Figure 5 is an exemplary view showing a dark line generated in the conventional direct type backlight unit.

First, as shown in FIG. 3, the lamp fixing device 4 is arranged at both sides of the external electrode 31 of the EEFL in a state fixed to the cover bottom 21 to receive power from the outside. The common electrode part 41 and the holder are fixed to the common electrode part and are configured in a ring shape to fix the external electrode of the EEFL.

On the other hand, in the EEFL as described above, the tube voltage is higher than the CCFL, and the tube voltage needs to be increased to increase the brightness. However, when the tube voltage exceeds 2000 Vrms, ozone is generated.

As a method for reducing the tube voltage, the method of lengthening the length of the external electrode 31 is best, but the method is limited because the size of the LCD bezel is limited. Thus, a method as shown in FIG. 4 has been proposed in which a portion of the external electrode 31 is exposed inside the backlight unit. But. In the case of applying this method, when the length of the exposed external electrode 31 becomes long, there is a problem that dark dark lines 35 are generated around the side support 28 of the backlight unit as shown in FIG. 5.

That is, the external electrode fluorescent lamp is a method using wall-charge of glass tube, and the capacitance of the external electrode 31 is proportional to the contact area of the glass tube 32 and the external electrode 31 and Since it is inversely proportional to the thickness, the longer the length of the outer electrode 31 surrounding the outer circumferential surface of the glass tube, the higher the brightness can be obtained. Therefore, in order to achieve high brightness and high efficiency in the display panel, the external electrode 31, which is a non-light emitting area, should occupy a predetermined portion or more.

However, when the length of the external electrode 31 is increased, the effective light emitting surface in the glass tube (lamp) is relatively reduced, and the non-light emitting area is increased, and when it is substantially employed in the backlight, the external electrode 31 There is a problem in that a bezel region having a rectangular frame shape as shown in FIG. 5 that surrounds an edge region of the display panel corresponding to the non-light emitting region, that is, an image display region, becomes wider.

As a result, in order to configure a display device employing an external electrode lamp (EEFL) with an image display area having the same size as a conventional cold cathode tube lamp (CCFL) model, it is necessary to increase the outer dimensions of the bezel area, which is a non-display area. It is done.

Accordingly, an object of the present invention for solving the above problems is to provide a lamp fixing device of a backlight unit having an auxiliary electrode that can extend the external electrode region.

In order to achieve the above object, the lamp fixing device of the backlight unit according to the present invention includes a holder for wrapping the external electrode of the external electrode lamp mounted on the backlight unit while transmitting a common voltage to the external electrode; A common electrode having the same number of external electrode lamps as the number of external electrode lamps mounted on the backlight unit, the common electrode for transmitting to the holder by receiving a common voltage from the outside; And auxiliary electrodes protruding from the common electrode in the longitudinal direction of the external electrode lamps fixed by the holder.

The common electrode may be fixed to a cover bottom to which a reflecting plate is attached.

In addition, the holder has an annular shape in which one side that is not attached to the common electrode is open, and is fixed while surrounding the external electrode through the open portion while being coupled to the common electrode. .

In addition, the auxiliary electrode is characterized in that formed longer than the length of the external electrode.

In addition, the interval G between the external electrode and the auxiliary electrode is characterized in that 0mm to 10mm.

The apparatus may further include a common electrode pedestal of an insulating material that is fixed to a cover bottom to which a reflecting plate is attached to the backlight unit to support the common electrode and the auxiliary electrode.

In addition, the width of the common electrode pedestal is characterized in that it is formed longer than the auxiliary electrode.

In addition, the width of the common electrode pedestal is characterized in that it is formed shorter than the auxiliary electrode.

In addition, the surface of the auxiliary electrode in contact with the external electrode lamp, characterized in that the light emitted from the external electrode lamp is made of a reflective material that can reflect the upper end of the external electrode lamp.

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

6 is a plan view showing a state in which the lamp fixing device of the backlight unit according to the present invention is disposed on the cover bottom. FIG. 7 is a front view illustrating a state in which a lamp fixing device of the backlight unit illustrated in FIG. 6 is disposed at a cover bottom, and illustrates an external electrode lamp (EEFL) 30 connected thereto. 8 is a side view illustrating a state in which a lamp fixing device of the backlight unit illustrated in FIG. 6 is disposed at a cover bottom, and illustrates a state in which an external electrode lamp is connected. 9 is a chart showing the tube voltage versus luminance relationship of the external electrode lamp with or without the auxiliary electrode.

That is, the lamp fixing device of the backlight unit according to the present invention, as shown in the drawings, the holder 51 for wrapping the external electrode of the external electrode lamp and transmitting a common voltage to the external electrode, mounted on the backlight unit The holders corresponding to the number of external electrode lamps are arranged at intervals of the external electrode lamps, and in the longitudinal direction of the external electrode lamps fixed by the holder and the common electrode 52 for transmitting a common voltage from the outside to the holder. The auxiliary electrodes 53 protruding from the common electrode are included.

First, as shown in FIG. 8, the holder 51 is coupled to the common electrode 52 and has an open ring shape at one side thereof, so that the holder 51 is coupled to the common electrode 52. The external electrode 31 may be fixed as if it surrounds the external electrode 31. That is, the holder 51 may be configured using a socket structure to fix the external electrode 31 to the common electrode 52.

In addition, the auxiliary electrode 53 is disposed in a one-to-one relationship with the holder 51 and protrudes from the common electrode 52 in the longitudinal direction of the external electrode 31 fixed to the holder 51. It is done. That is, the common electrode 52 at the lower portion of the holder 51 is protruded to form the auxiliary electrode 53. In this case, the auxiliary electrode 53 is preferably formed longer than the length of the external electrode 31 of the external electrode lamp.

In addition, the height or thickness of the holder may be adjusted so that the external electrode 31 or the glass tube 32 and the auxiliary electrode 53 may be maintained at a predetermined interval G. In this case, the distance G between the external electrode 31 or the glass tube (lamp) 32 and the auxiliary electrode 53 is preferably 0 mm to 10 mm.

On the other hand, the common electrode 52, the holder 51 and the auxiliary electrode 53 are all made of a conductor, the cover bottom 21 is also made of a metallic material, the common electrode 52 and the auxiliary In order to insulate the electrode 53 from the cover bottom 21 or the reflector 22, the common electrode 52 and the auxiliary electrode 53 may be supported by the common electrode support 54 made of an insulating material. That is, the common electrode 52 and the auxiliary electrode 53 may be directly fixed to the cover bottom 21 or the reflecting plate 22, but the cover bocom 21 may be fixed by the common electrode support 54 made of an insulating material. Or fixed to the reflector plate 22. In other words, since the high voltage is applied to the auxiliary electrode 53 or the common electrode 52 together with the external electrode 31 of the external electrode lamp, a lower portion of the common electrode 52 or the auxiliary electrode 53 is used for insulation. As shown in FIG. 7, the common electrode pedestal 54 may be formed to cover only a portion of the lower portion of the auxiliary electrode 53, as shown in the left side of FIG. 7. It may be formed to cover the entire auxiliary electrode 53 as shown on the right.

In addition, since the reflector 22 is attached to the cover bottom 21 to reflect light emitted from the external electrode lamp, the common electrode 52 or the common electrode pedestal 54 may also have a It comes in contact with the reflector.

On the other hand, in order to support the function of the reflective plate 22, it is preferable to coat a reflective material capable of functioning as the reflective plate on the auxiliary electrode 53, or to configure the auxiliary electrode of a conductive reflective material. .

That is, in the liquid crystal display device, the most important point is to efficiently use the light of the external electrode lamp EEFL. Therefore, by using the auxiliary electrode 53 disposed at the lower end of the external electrode lamp EEFL as a reflector, the external electrode It is possible to maximize the luminous efficiency of the lamp (EEFL).

In the lamp fixing apparatus of the backlight unit according to the present invention as described above, an auxiliary electrode 53 capable of performing the same function as the external electrode 31 of the external electrode lamp is added to the common electrode 52. .

That is, the external electrode lamp can be driven with a low tube voltage at the same brightness due to the function of the auxiliary electrode 53, thereby shortening the length (electrode length) of the glass tube 32 of the external electrode lamp. Narroe bezel) is also applicable to the structure.

Furthermore, by attaching a material having a high reflectance or using a material having a high reflectance on the auxiliary electrode 53 facing the glass tube (lamp) 32 of the external electrode lamp, the reflectance of the light emitted from the external electrode lamp is increased. It can increase.

On the other hand, Figure 9 shows the characteristics of the external electrode lamps before and after using the lamp fixing device of the backlight unit according to the present invention, when comparing the tube voltage at the same brightness 12000 [nit] is about 1570 when using the auxiliary electrode 53 [Vrms], and when not used, it is about 1650 [Vrms] and about 80 [Vrms] is lowered.

At this time, the effect of the auxiliary electrode 53 is the distance (G) of the length of the auxiliary electrode and the external electrode lamp, the length of the glass tube (lamp) 32 of the external electrode lamp, the length of the external electrode 31, the drive inverter (inverter) Although it may vary depending on the like, it can be seen that the influence of the length of the auxiliary electrode 53 and the gap G is greatest.

The lamp fixing apparatus of the backlight unit according to the present invention as described above, by forming an auxiliary electrode that can assist the function of the external electrode of the external electrode lamp in the common electrode, thereby minimizing the non-light-emitting area due to the external electrode, There is an excellent effect that the length of the external electrode lamp can be optimized.

In addition, the present invention has an excellent effect that can implement a high brightness and high efficiency backlight unit.

In addition, the present invention has an excellent effect that can reduce the tube voltage of the external electrode lamp.

In addition, the present invention has an excellent effect that can enable a Neroroe Bezel (Narroe Bezel) structure.

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 (9)

A holder for wrapping an external electrode of the external electrode lamp mounted on the backlight unit and transmitting a common voltage to the external electrode; A common electrode having the same number of external electrode lamps as the number of external electrode lamps mounted on the backlight unit, the common electrode for transmitting to the holder by receiving a common voltage from the outside; And Lamp fixing device of the backlight unit including auxiliary electrodes protruding from the common electrode in the longitudinal direction of the external electrode lamps fixed by the holder. The method of claim 1, The common electrode is a lamp fixing device of the backlight unit, characterized in that fixed to the cover bottom attached to the reflecting plate of the backlight unit. The method of claim 1, The holder has a ring shape in which one side that is not attached to the common electrode is open and fixed while surrounding the external electrode through the open portion while being coupled to the common electrode. Lamp fixture. The method of claim 1, The auxiliary electrode is a lamp fixing device of the backlight unit, characterized in that formed longer than the length of the external electrode. The method of claim 1, The interval G between the external electrode and the auxiliary electrode is a lamp fixing device of the backlight unit, characterized in that 0mm to 10mm. The method of claim 1, The lamp fixing device of the backlight unit further comprises a common electrode support of the insulating material is fixed to the cover bottom attached to the reflecting plate of the backlight unit to support the common electrode and the auxiliary electrode. The method of claim 6, The lamp fixing device of the backlight unit, characterized in that the width of the common electrode support is formed longer than the auxiliary electrode. The method of claim 6, The lamp fixing device of the backlight unit, characterized in that the width of the common electrode support is formed shorter than the auxiliary electrode. The method of claim 1, The surface of the auxiliary electrode in contact with the external electrode lamp, the lamp fixing device of the backlight unit, characterized in that made of a reflective material that can reflect the light emitted from the external electrode lamp to the upper end of the external electrode lamp.

Images