KR20070072003A - Fluirescent lamp and backlight assembly having the same and liquid crystal display device - Google Patents

Abstract

A fluorescent lamp, a backlight assembly and an LCD(Liquid Crystal Display) including the same are provided to prevent darkness from occurring at an edge by forming one of a convex lens and a concave lens as a light diffusion unit at both sides of a glass tube and thus changing a light path. A glass tube(111) has a light diffusion unit at both sides. A fluorescent material(117) is applied on an inner surface of the glass tube. An electrode is disposed at inner portions of both sides of the glass tube. The light diffusion unit includes any one of a convex lens and a concave lens. The light diffusion unit is formed integrally with the glass tube.

Description

Fluorescent lamp, backlight assembly and liquid crystal display device having the same {FLUIRESCENT LAMP AND BACKLIGHT ASSEMBLY HAVING THE SAME AND LIQUID CRYSTAL DISPLAY DEVICE}

1A is a plan view illustrating a backlight assembly of a conventional liquid crystal display device.

1B is a perspective view of a conventional fluorescent lamp.

FIG. 1C is a cross-sectional view taken along the line II ′ of FIG. 1B. FIG.

2A is an exploded perspective view illustrating a liquid crystal display device according to a first embodiment of the present invention.

2B is a plan view illustrating a backlight assembly of the liquid crystal display according to the first embodiment of the present invention.

Figure 2c is a perspective view showing a cold cathode fluorescent lamp according to the first embodiment according to the present invention.

FIG. 2D is a cross-sectional view taken along the line II-II 'of FIG. 2C;

Figure 3a is a cross-sectional view showing a cold cathode fluorescent lamp according to a second embodiment of the present invention.

3B is a cross-sectional view showing an external electrode fluorescent lamp according to a third embodiment of the present invention.

3C is a cross-sectional view of an external electrode fluorescent lamp according to a fourth exemplary embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

100: liquid crystal panel 110: cold cathode fluorescent lamp

111: glass tube 113, 113 ': electrode of an anode and a cathode

115, 115 ': First and second power supply leads 117: fluorescent material

119: mixed gas 120: backlight assembly

130, 130 ': first and second lamp holder 150: light guide plate

160: reflector 170: bottom case

180: optical sheet 200, 200 ', 400, 400': convex lens

300, 300 ', 500, 500': concave lens

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a fluorescent lamp capable of improving edge darkening, a backlight assembly having the same, and a liquid crystal display.

CRT (Cathode Ray Tube), one of the widely used display devices, is mainly used for monitors such as TVs, measuring devices, information terminal devices, etc., but due to the weight and size of the CRT itself, the miniaturization and weight reduction of electronic products Could not actively respond to the response.

As a solution to this problem, the liquid crystal display device has an advantage that it is possible to realize the light and thin end size and low power consumption compared to the CRT. In particular, liquid crystal displays using thin film transistors have been used in various fields in the notebook PC and monitor market as well as in recent years since they have achieved high quality, large size, and color display screen comparable to CRTs.

The liquid crystal display device includes a liquid crystal panel for displaying an image and a driving circuit for driving the liquid crystal panel.

Since the liquid crystal display is not a self-luminous display, a back light assembly is required. The backlight assembly has two types, a direct type and an edge type, depending on the position of the light source. In the edge type system, a light source is disposed outside the flat plate, and the light emitted from the light source is irradiated to the entire surface of the liquid crystal panel using a light guide plate. On the other hand, the direct type method has a light source on the back of the liquid crystal panel directly dimming the front of the liquid crystal panel in comparison with the edge type method can be arranged to increase the brightness by increasing the light source and wider light emitting surface has the advantage .

1A is a plan view illustrating a backlight assembly of a conventional liquid crystal display, FIG. 1B is a perspective view of a conventional fluorescent lamp, and FIG. 1C is a cross-sectional view taken along the line II ′ of FIG. 1B.

As shown in FIGS. 1A and 1B, a conventional backlight assembly includes a cold cathode fluorescent lamp (CCFL) 10 mounted on a side thereof to emit light, and the cold cathode fluorescent lamp 10 is fixed thereto. And supporting first and second lamp holders 30 and 30 ', and a light guide plate 50 for converting light generated from the cold cathode fluorescent lamp 10 into a surface light source.

Although not shown, the backlight assembly is provided on a rear surface of the light guide plate 50 to reflect light, and an optical sheet provided on the light guide plate 50 to diffuse and focus light. C) is further included.

The cold cathode fluorescent lamp (CCFL) 10 used as the light source includes a glass tube 11, electrodes 13 and 13 ′ of cathodes and anodes provided at both ends of the glass tube 11, and electrodes of the cathode and anode ( 13 and 13 ′, the first and second power lead wires 15 and 15 ′ as a connecting means for applying a voltage to the glass, the fluorescent material 17 applied to the inner wall of the glass tube 11, and the glass tube 11. It includes a mixed gas 19 that is injected inside and is made of neon (Ne), argon (Ar), mercury (Hg) and the like.

In the cold cathode fluorescent lamp 10, when a voltage is applied between the electrodes 13 and 13 ′ of the cathode and the anode, electrons existing in the glass tube 11 are attracted to the electrode and move at high speed to collide with the electrode. Primary electrons are emitted. As a result, discharge starts. Electrons flowing by the discharge collide with mercury electrons in the glass tube 10 to generate ultraviolet rays, and the ultraviolet rays excite the fluorescent material 17 to emit visible light.

The backlight assembly is provided on both sides of the cold cathode fluorescent lamp 10 so that the first and second lamp holders 30 and 30 'fixing and supporting the cold cathode fluorescent lamp 10 are generally the cold cathode fluorescent lamp. (10) An opaque rubber material is used, which is arranged in such a way as to surround a predetermined area on both sides.

Accordingly, in the conventional liquid crystal display device, the light irradiated from the cold cathode fluorescent lamp 10 is transmitted by the first and second lamp holders 30 and 30 'to the first and second lamp holders 30 and 30'. There is a problem that a dark phenomenon occurs because it is not transmitted through the edge region (A) of the light guide plate corresponding to the. Accordingly, there is a problem that luminance unevenness is caused by the darkening of the edge area A when displaying an image. In particular, in the case of the prism light guide plate, there is a more severe edge luminance imbalance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluorescent lamp for improving edge darkening by providing a glass tube having light diffusing means for changing an optical path, a backlight assembly having the same, and a liquid crystal display device.

In order to achieve the above object, a fluorescent lamp according to a first embodiment of the present invention,

A glass tube having light diffusing means on both sides;

A fluorescent material coated on the inner surface of the glass tube; And

It includes; the electrode disposed inside both sides of the glass tube.

In addition, the fluorescent lamp according to the second embodiment of the present invention,

A glass tube having light diffusing means on both sides;

A fluorescent material coated on the inner surface of the glass tube; And

It includes; the electrode disposed on both outside of the glass tube.

In addition, the backlight assembly according to the third embodiment of the present invention,

A fluorescent lamp emitting light and having light diffusing means formed at both sides thereof; And

It includes; a light guide plate disposed on the side of the fluorescent lamp to convert to a surface light source.

In the liquid crystal display device according to the fourth embodiment of the present invention,

A fluorescent lamp emitting light and having light diffusing means on both sides; And

It includes; a liquid crystal panel for displaying a predetermined image using the light supplied from the fluorescent lamp.

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

2A is an exploded perspective view illustrating a liquid crystal display according to a first embodiment of the present invention, and FIG. 2B is a plan view illustrating a backlight assembly of the liquid crystal display according to the first embodiment of the present invention.

2A and 2B, the liquid crystal display according to the first embodiment includes a liquid crystal panel 100 for displaying an image and a backlight assembly 120 for providing light to the liquid crystal panel 100. It is configured by.

The backlight assembly 120 includes a bottom case 170, a light guide plate 150 disposed on the bottom case 170 to guide light forward, and a side surface of the light guide plate 150 to emit light. It is attached to the cold cathode fluorescent lamp 110, the first and second lamp holders 130 and 130 'fixing the cold cathode fluorescent lamp 110, and the bottom surface of the light guide plate 150 to reflect light forward. It includes a reflecting plate 160 and an optical sheet 180 disposed on the light guide plate 150 for diffusing and condensing light.

In the cold cathode fluorescent lamp 110 according to the first embodiment, first and second power lead wires 115 and 115 ′ which transfer power for driving are connected to both sides, and the first and second power lead wires ( 115 and 115 'are connected to the connector 112 and to a drive circuit of an external inverter (not shown).

Convex lenses 200 and 200 ′ are formed on both sides of the cold cathode fluorescent lamp 110 and the glass tube to protrude convexly toward the light guide plate 150.

The convex lenses 200 and 200 ′ are formed during the glass tube forming process of the cold cathode fluorescent lamp 110 and are integrally formed with the glass tube.

The convex lenses 200 and 200 ′ are formed in the direction of the light guide plate 150 and serve to diffuse the light by changing the light path (→).

The convex lenses 200 and 200 ′ have a focus P between the cold cathode fluorescent lamp 110 and the light guide plate 150, and the focus P is a curvature of the convex lenses 200 and 200 ′. The position can be adjusted according to 에).

In the liquid crystal display of the first embodiment, when power is applied to the cold cathode fluorescent lamp 100 through the first and second power lead lines 115 and 115 ', light is emitted to the side of the light guide plate 150. Incident. In this case, the light emitted from both sides of the cold cathode fluorescent lamp 100 by the convex lenses 200 and 200 'formed at both sides of the cold cathode fluorescent lamp 110 is changed in the optical path (→) to thereby change the first and Predetermined light is incident on the edge of the light guide plate 150 corresponding to the second lamp holders 130 and 130 ′.

Accordingly, in the liquid crystal display according to the first exemplary embodiment of the present invention, the convex lenses 200 and 200 'are formed on both sides of the cold cathode fluorescent lamp 100 to change the path of the light so as to change the first and second lamp holders 130. , The edge darkening caused by the first and second lamp holders 130 and 130 ′ may be improved by guiding the edge of the light guide plate 150 to the edge region of the light guide plate 150.

FIG. 2C is a perspective view illustrating a cold cathode fluorescent lamp according to the first exemplary embodiment of the present invention, and FIG. 2D is a cross-sectional view taken along the line II-II ′ of FIG. 2C.

As illustrated in FIGS. 2C and 2D, the cold cathode fluorescent lamp according to the first embodiment includes a glass tube 111 and electrodes 113 and 113 ′ of cathodes and anodes provided at both ends of the glass tube 111. And first and second power lead wires 115 and 115 'connected to deliver power to the electrodes 113 and 113' of the cathode and anode, and the fluorescent material 117 coated on the inner wall of the glass tube 111. And a mixed gas 119 made of neon (Ne), argon (Ar), mercury (Hg), or the like injected into the glass tube 111.

First and second lamp holders 130 and 130 'are provided at both sides of the cold cathode fluorescent lamp to fix the cold cathode fluorescent lamp.

The first and second lamp holders 130 and 130 'are formed of a rubber material to facilitate fixing of the cold cathode fluorescent lamp, and have characteristics of preventing light from passing through.

Convex lenses 200 and 200 ′ are formed at both sides of the glass tube 111, and the convex lenses 200 and 200 ′ are formed during the formation process of the glass tube 111 and are integrally formed with the glass tube 111. ..

The convex lenses 200 and 200 ′ may be formed as a boundary between regions where the first and second lamp holders 130 and 130 ′ are disposed, and the first and second lamp holders 130 and 130 ′ may be formed. May be formed in an area in which is not disposed.

The convex lenses 200 and 200 ′ have an arbitrary focus P in their characteristics, and the optical path → is changed based on the focus P. FIG. The focus P may be adjusted in position according to the curvature of the convex lenses 200 and 200 ′.

The convex lenses 200 and 200 ′ may improve edge darkness in which light cannot be transmitted by the first and second lamp holders 130 and 130 ′ by changing the light path →.

When voltage is applied to the electrodes 113 and 113 ′ of the cathode and the anode, electrons existing in the glass tube 111 are attracted to the electrode, move at high speed, and collide with the electrode to emit secondary electrons. As a result, discharge starts. Electrons flowing by the discharge collide with the mixed gas 119 in the glass tube 111 to generate ultraviolet rays, and the ultraviolet rays excite the fluorescent material 117 to emit visible light. At this time, since the first and second lamp holders 130 and 130 'are wrapped on both side surfaces of the glass tube 111, light cannot be transmitted. Convex lenses 200 and 200 'are formed at both sides of the glass tube 111 so that light is incident on a region corresponding to the first and second lamp holders 130 and 130' by changing the path of light (→). .

3A is a cross-sectional view illustrating a cold cathode fluorescent lamp according to a second embodiment of the present invention.

As shown in FIG. 3A, the cold cathode fluorescent lamp according to the second embodiment is the same as the other components except for the glass tube 111 among the components of the cold cathode fluorescent lamp according to the first embodiment. The description of these fields will be omitted.

In the glass tube 111, concave-shaped concave lenses 300 and 300 ′ are formed at both sides of regions where the first and second lamp holders 130 and 130 ′ are not disposed.

The concave lenses 300 and 300 ′ may be formed during the glass tube 111 forming process and may be integrally formed with the glass tube 111.

The cold cathode fluorescent lamp according to the second embodiment emits light when a voltage is applied. In this case, the light emitted through the concave lenses 300 and 300 ′ is diffused by changing the optical path (→) by the concave lenses 300 and 300 ′.

Accordingly, in the cold cathode fluorescent lamp according to the second embodiment, concave lenses 111 for diffusing light are formed on both sides of the glass tube 111, and the edges of the cold cathode fluorescent lamps are formed by the first and second lamp holders 130 and 130 ′. The darkness of the area can be improved.

3B is a cross-sectional view illustrating an external electrode fluorescent lamp according to a third embodiment of the present invention, and FIG. 3C is a cross-sectional view showing an external electrode fluorescent lamp according to a fourth embodiment of the present invention.

As shown in FIGS. 3B and 3C, the external electrode fluorescent lamps according to the third and fourth embodiments may include the cathodes 230 and the positive and negative electrodes 230, respectively, of the cold cathode fluorescent lamps of the first and second embodiments. 230 ') is the same as other components except for the description of the same components will be omitted.

The external electrode fluorescent lamps (EEFL) according to the third and fourth embodiments are formed in which the electrodes 213 and 213 'of the cathode and the anode are disposed outside both sides of the glass tube 111. The light cannot be emitted from the electrodes 213 and 213 'of the cathode and the anode, and first and second lamp holders 130 and 130' are disposed on the electrode to connect the electrodes of the cathode and the anode to the glass tube. Even if it is arranged on both sides of the 111, light is not emitted from both sides of the glass tube 111 by the first and second lamp holders 130 and 130 '.

In the external electrode fluorescent lamp of the third embodiment, convex lenses 400 and 400 'are formed on both sides of the glass tube 111 where the electrodes 213 and 213' of the cathode and anode are not formed, and the convex lenses 400 and 400 'is formed during the glass tube 111 forming process and is integrally formed with the glass tube 111.

The convex lenses 400 and 400 ′ have an arbitrary focus P in their characteristics, and the optical path → is changed based on the focus P. FIG. The focus P may be adjusted in position according to the curvature of the convex lenses 400 and 400 ′.

In the external electrode fluorescent lamp of the fourth embodiment, concave lenses 500 and 500 'are formed on both sides of the glass tube 111 where the electrodes 213 and 213' of the cathode and the anode are not formed. 500 'is formed during the glass tube 111 forming process and is integrally formed with the glass tube 111.

The concave lenses 500 and 500 ′ have a property of diffusing light, and the optical path → changes according to the curvature of the concave lenses 500 and 500 ′.

Accordingly, the external electrode fluorescent lamps according to the third and fourth embodiments form convex lenses 400 and 400 'or concave lenses 500 and 500' on both sides of the glass tube 111 to form an optical path (→). By changing, the edge darkening caused by the first and second lamp holders 130 and 130 'may be improved.

Referring to the first to fourth embodiments of the present invention, the cold cathode and the external electrode fluorescent lamps are convex lenses 200, 200 ′, 400, and 400 ′ as light diffusing means for changing light paths on both sides of the glass tube 111. Or concave lenses 300, 300 ', 500, and 500' to diffuse light into edge regions where light cannot be transmitted by the first and second lamp holders 130 and 130 ', thereby improving edge darkening. It is effective.

The first four fourth embodiments of the present invention have been described with respect to the edge type liquid crystal display device, but the present invention is not limited thereto, and the direct type liquid crystal is disposed on the rear surface of the liquid crystal panel at predetermined intervals to irradiate light directly under the liquid crystal panel. The edge darkening of the display device may also be improved by disposing the glass tube 111 having the convex lenses 200, 200 ′, 400, and 400 ′ or the concave lenses 300, 300 ′, 500, and 500 ′. Can be.

As described above, according to the present invention, the convex lens or the concave lens is formed on both sides of the glass tube by light diffusing means to change the optical path, thereby improving the edge darkening phenomenon.

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

Claims (12)

A glass tube having light diffusing means on both sides; A fluorescent material coated on the inner surface of the glass tube; And Fluorescent lamps, including; electrodes disposed inside both sides of the glass tube. The method of claim 1, And the light diffusing means is one of a convex lens or a concave lens shape. The method of claim 1, And the light diffusing means is integrally formed with the glass tube. A glass tube having light diffusing means on both sides; A fluorescent material coated on the inner surface of the glass tube; And Fluorescent lamps, including; electrodes disposed on both outer sides of the glass tube. The method of claim 4, wherein And the light diffusing means is one of a convex lens or a concave lens shape. The method of claim 4, wherein And the light diffusing means is integrally formed with the glass tube. A fluorescent lamp emitting light and having light diffusing means formed at both sides thereof; And And a light guide plate disposed on a side of the fluorescent lamp to convert to a surface light source. The method of claim 7, wherein The light diffusing means is integrally formed with the glass tube of the fluorescent lamp, the backlight assembly, characterized in that any one of a convex lens or concave lens shape. The method of claim 7, wherein The fluorescent lamp is a backlight assembly, characterized in that made of any one of a cold cathode fluorescent lamp or an external electrode fluorescent lamp. A plurality of fluorescent lamps disposed at predetermined intervals and having light diffusing means formed at both sides thereof; And And an optical sheet disposed on the plurality of fluorescent lamps for diffusing and condensing light. The method of claim 10, And the light diffusing means is formed integrally with the glass tube of the fluorescent lamp, and comprises any one of a convex lens or a concave lens shape. A fluorescent lamp emitting light and having light diffusing means on both sides; And And a liquid crystal panel displaying a predetermined image by using the light supplied from the fluorescent lamp.

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