KR20060089018A - Flat fluorescent lamp and liquid crystal display device having same - Google Patents

Abstract

Disclosed are a flat panel fluorescent lamp capable of improving appearance quality and a liquid crystal display device having the same. The planar fluorescent lamp includes a first substrate, a second substrate coupled to the first substrate to form discharge spaces spaced at regular intervals from each other, and intersect the discharge spaces on an outer surface of at least one of the first and second substrates. It includes an electrode formed. The second substrate has at least one diffusion plate support portion formed correspondingly between the discharge spaces to support the diffusion plate disposed thereon. The diffusion plate support part is made of the same material as that of the second substrate, and is formed at the same time as the forming process of the second substrate. Therefore, sagging of the diffusion plate can be prevented and the appearance quality of the liquid crystal display device can be improved.

Description

FLAT FLUORESCENT LAMP AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME}

1 is a perspective view showing a flat fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

3 is an enlarged view illustrating an enlarged portion A of FIG. 1.

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

<Explanation of symbols for the main parts of the drawings>

100 flat plate fluorescent lamp 110 first substrate

120: second substrate 130: electrode

140: discharge space 150: diffusion plate support

200: diffuser plate 210: optical sheet

300: liquid crystal display device 310: storage container

320: inverter 330: first mold

340: second mold 350: insulating member

360: top chassis

The present invention relates to a flat panel fluorescent lamp and a liquid crystal display having the same, and more particularly, to a flat panel fluorescent lamp and a liquid crystal display having the same that can prevent sagging of the diffusion plate.

In general, a liquid crystal display (LCD) is a display device that displays an image using a liquid crystal having optical and electrical characteristics such as anisotropic refractive index and anisotropic dielectric constant. Such liquid crystal displays are thinner and lighter than other display devices such as CRTs and PDPs, and have low driving voltages and low power consumption, and thus are widely used throughout the industry.

Such a liquid crystal display device requires a separate light source for supplying light to the liquid crystal display panel because the liquid crystal display panel for displaying an image is a non-light emitting device that does not emit light by itself.

As a conventional light source, an elongated cylindrical cold cathode fluorescent lamp (CCFL) is mainly used. However, as the size of the liquid crystal display increases, the number of cold cathode fluorescent lamps required increases, resulting in an increase in manufacturing cost and inferior optical characteristics such as luminance uniformity.

In order to solve this problem, recently, a flat fluorescent lamp that directly emits light in the form of a plane has been developed. The flat fluorescent lamp has a structure divided into a plurality of discharge spaces for improving the discharge efficiency and uniform light emission over a large area. The flat fluorescent lamp generates plasma discharge in each discharge space in response to the discharge voltage applied from the inverter. At this time, the fluorescent film formed inside the flat fluorescent lamp is excited by ultraviolet rays generated by plasma discharge to generate visible light.

On the other hand, since the flat fluorescent lamp has a structure in which the internal space is divided into a plurality of discharge spaces for efficient light emission, apparent dark lines are generated between the discharge spaces adjacent to each other where no light is generated. In order to remove such dark lines and improve luminance uniformity, the liquid crystal display further includes a diffusion plate disposed on the flat fluorescent lamp.

However, as the size of the diffusion plate increases, the appearance characteristics of the diffusion plate decrease due to deflection in the direction of the flat fluorescent lamp, and when the impact is applied from the outside, the diffuser plate and the flat fluorescent lamp collide with each other and the flat fluorescent lamp is damaged. Is generated.

Accordingly, the present invention has been made in view of such a problem, and the present invention provides a flat fluorescent lamp that can prevent sagging of the diffusion plate and improve appearance characteristics.

In addition, the present invention provides a liquid crystal display device having the flat plate fluorescent lamp as described above.

The planar fluorescent lamp according to an aspect of the present invention described above includes a first substrate, a second substrate, and an electrode.

The second substrate is combined with the first substrate to form discharge spaces spaced apart from each other at regular intervals. The second substrate includes at least one diffusion plate support part formed corresponding to the discharge spaces to support the diffusion plate disposed thereon.

The electrode is formed to intersect the discharge spaces on an outer surface of at least one of the first substrate and the second substrate.

A liquid crystal display device according to an aspect of the present invention includes a flat fluorescent lamp, a diffusion plate and a liquid crystal display panel.

The plate fluorescent lamp includes a first substrate, a second substrate, and an electrode. The second substrate is combined with the first substrate to form discharge spaces spaced apart from each other by a predetermined interval, and includes at least one diffusion plate support part formed correspondingly between the discharge spaces. The electrode is formed to intersect the discharge spaces on an outer surface of at least one of the first substrate and the second substrate.

The diffusion plate is disposed above the flat plate fluorescent lamp and is supported by the diffusion plate support unit.

The liquid crystal display panel is disposed above the diffusion plate and displays an image by using light supplied from the flat fluorescent lamp.

According to the flat panel fluorescent lamp and the liquid crystal display device having the same, it is possible to prevent sagging of the diffuser plate and to maintain a constant distance between the diffuser plate and the flat panel fluorescent lamp to improve appearance characteristics.

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

1 is a perspective view illustrating a flat fluorescent lamp according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1, and FIG. 3 is an enlarged view of a portion A of FIG. to be.

1 and 2, a planar fluorescent lamp 100 according to an embodiment of the present invention includes a first substrate 110, a second substrate 120, and an electrode 130.

The first substrate 110 has a rectangular plate shape. The first substrate 110 is made of, for example, a glass material. The first substrate 110 may include a material that blocks ultraviolet rays so that ultraviolet rays generated in the discharge spaces 140 do not leak.

The second substrate 120 is combined with the first substrate 110 to form the discharge spaces 140 spaced apart from each other at regular intervals. The second substrate 120 is made of a transparent material through which visible light generated in the discharge spaces 140 can pass. For example, the second substrate 120 is made of glass. The second substrate 120 may include a material that blocks ultraviolet rays so that ultraviolet rays generated in the discharge spaces 140 do not leak.

The second substrate 120 is a substrate processed to form the discharge spaces 140. The molding process of the second substrate 120 may be performed by various methods. For example, the second substrate 120 is manufactured by a method of heating a glass substrate having the same plate shape as the first substrate 110 to a predetermined temperature and then molding through a mold having a desired shape. In addition, the second substrate 120 may be formed by various methods such as heating the plate-shaped glass substrate and processing the shape by suction of air.

The molded second substrate 120 includes discharge spaces 122, space dividers 124, and a sealing part 126 to form discharge spaces 140. The discharge spaces 122 are spaced apart from the first substrate 110 to form the discharge spaces 140. The space dividing portions 124 are positioned between the discharge space portions 122 and divide the discharge spaces 140 in contact with the first substrate 110. The sealing part 126 is positioned at the edge of the second substrate 120 and is coupled to the first substrate 110. As shown in FIG. 2, the longitudinal cross-section of the second substrate 120 has a shape in which the arcuate discharge spaces 122 are continuously spaced apart at regular intervals. For example, the discharge spaces 122 are formed to be spaced apart at a distance of about 4 mm. In contrast, the second substrate 120 may be formed such that longitudinal cross-sections of the discharge spaces 122 have various shapes such as semicircles, quadrangles, and trapezoids.

In the present embodiment, the second substrate 120 includes at least one diffuser support part 150 for supporting the diffuser plate 200 disposed thereon. The diffusion plate support part 150 is formed correspondingly between the discharge spaces 140. That is, the diffusion plate support part 150 is formed in the space dividing part 124. The diffusion plate support part 150 prevents the deflection plate 200 from sagging and maintains the distance between the flat fluorescent lamp 100 and the diffusion plate 200 at a constant distance from the second substrate 120. Projected at a predetermined height in the direction of? The diffusion plate support part 150 is formed evenly over the entire area of the second substrate 120 to stably support the diffusion plate 200. The number and formation positions of the diffusion plate support part 150 may be variously modified.

The diffusion plate support part 150 is formed of the same transparent glass material as the second substrate 120 in order to prevent it from being seen from the outside. The diffusion plate support part 150 is formed at the same time during the molding process of the second substrate 120. In another embodiment, the transparent glass diffusion plate support 150 may be attached to the second substrate 120 by a transparent adhesive.

Referring to FIG. 3, the diffusion plate support part 150 is formed in a cone shape having a predetermined height. At this time, the end of the diffusion plate support portion 150 which is in contact with the diffusion plate 200 has a round shape in order not to damage the diffusion plate 200. Meanwhile, the diffuser plate supporter 150 may have various shapes that can support the diffuser plate 200 without damaging the diffuser plate 200.

1 and 2, a connection passage 128 for connecting discharge spaces 140 adjacent to each other is formed in the second substrate 120. At least one connection passage 128 is formed in each space division part 124. The connection passage 128 may provide a passage through which air or discharge gas may move when exhausting air existing in the discharge spaces 140 or injecting discharge gas into the discharge spaces 140. The connection passage 128 is formed at the same time during the molding process of the second substrate 120. The connection passage 128 may have various shapes as long as it can connect the adjacent discharge spaces 140 with each other. For example, the connection passage 128 has a structure bent in an S shape. As such, when the connection passage 128 has a structure bent in an S shape, a moving path through which the discharge gas may move is long, and thus, a drift phenomenon due to mutual interference between adjacent discharge spaces 140 may be effectively prevented.

The first substrate 110 and the second substrate 120 are coupled to each other through the adhesive member 160. For example, the adhesive member 160 may be formed of a frit that is a mixture of glass and metal having a lower melting point than glass. The frit is disposed at a position corresponding to the sealing portion 126 between the first substrate 110 and the second substrate 120 to couple the first substrate 110 and the second substrate 120. The frit disposed between the first substrate 110 and the second substrate 120 is melted by heat applied from the outside to bond the first substrate 110 and the second substrate 120 to each other. This bonding process takes place, for example, at about 400 ° C to about 600 ° C.

The space dividers 124 of the second substrate 120 are in close contact with the first substrate 110 by the pressure difference between the inside and the outside of the flat fluorescent lamp 100. Specifically, after the combination of the first substrate 110 and the second substrate 120 to exhaust the air present in the discharge spaces 140 to make a vacuum state, thereafter, the discharge spaces 140 for plasma discharge Various kinds of discharge gases are injected. For example, the discharge gas includes mercury (Hg), neon (Ne), argon (Ar), and the like. The gas pressure of the discharge gas existing in the discharge spaces 140 is about 50 torr to about 70 torr, and a pressure difference is generated compared to the external atmospheric pressure of 760 torr. Due to this pressure difference, a force directed from the outside to the inside of the flat fluorescent lamp 100 is generated, and the space dividing portions 124 are in close contact with the first substrate 110 by this force.

The planar fluorescent lamp 100 further includes a first fluorescent film 170 and a second fluorescent film 180 formed on inner surfaces of the first substrate 110 and the second substrate 120 facing each other. The first fluorescent film 170 and the second fluorescent film 180 are excited by ultraviolet rays generated through plasma discharge in the discharge spaces 140 to emit visible light.

The planar fluorescent lamp 100 further includes a reflective film 190 formed between the first substrate 110 and the first fluorescent film 170. The reflective film 190 reflects the visible light generated by the first fluorescent film 170 and the second fluorescent film 180 to prevent the visible light from leaking through the first substrate 110.

Although not shown, the planar fluorescent lamp 100 may further include a protective film formed between the first substrate 110 and the reflective film 190 and / or between the second substrate 120 and the second fluorescent film 180. Can be. The protective layer prevents chemical reaction between the first substrate 110 or the second substrate 120 and mercury (Hg), which is a main component of the discharge gas, to prevent the loss and blackening of mercury.

The electrode 130 is formed to intersect the discharge spaces 140 on the outer surface of at least one of the first substrate 110 and the second substrate 120. When the electrodes 130 are formed on the first substrate 110 and the second substrate 120, respectively, they may be electrically connected to each other through a connecting means such as a conductive clip (not shown). Alternatively, the electrode 130 may be formed inside the flat fluorescent lamp 100.

The electrode 130 is made of a conductive material to apply a discharge voltage generated from an external inverter to the discharge spaces 140. For example, the electrode 130 is formed by coating silver paste (Ag Paste), which is a mixture of silver (Ag) and silicon oxide (SiO ₂ ). In addition, the electrode 130 may be formed by spray coating a metal powder (Metal Powder) made of a metal or a metal mixture. Although not shown, an insulating film for protecting the electrode 130 may be further formed outside the electrode 130.

4 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention. In the present embodiment, since the flat fluorescent lamp has the same configuration as that shown in Figs. 1 to 3, the same reference numerals are used, and detailed description thereof will be omitted.

Referring to FIG. 4, the liquid crystal display 300 according to the exemplary embodiment of the present invention includes a flat fluorescent lamp 100, a diffusion plate 200, and a display unit 400.

The diffusion plate 200 is disposed above the flat plate fluorescent lamp 100 and is supported by the diffuser plate supporting unit 150 of the flat plate fluorescent lamp 100. The diffusion plate 200 diffuses the light emitted from the flat plate fluorescent lamp 100 to improve the brightness uniformity of the light. The diffusion plate 200 is formed in a plate shape having a predetermined thickness and is spaced apart from the plate fluorescent lamp 100 at a predetermined interval. The diffusion plate 200 is made of a transparent material for transmitting light, and includes a diffusion agent for diffusing light. The diffusion plate 200 is made of, for example, polymethyl methacrylate (PMMA) material.

The display unit 400 includes a liquid crystal display panel 410 for displaying an image using light supplied from the flat panel fluorescent lamp 100 and a driving circuit unit 420 for driving the liquid crystal display panel 410.

The liquid crystal display panel 410 is disposed on the diffusion plate 200. The liquid crystal display panel 410 includes a first substrate 412, a second substrate 414 coupled to the first substrate 412, and a liquid crystal interposed between the first substrate 412 and the second substrate 414. Layer 416.

The first substrate 412 is a TFT substrate in which thin film transistors (hereinafter referred to as TFTs), which are switching elements, are formed in a matrix form. For example, the first substrate 412 is made of glass. A data line and a gate line are respectively connected to the source terminal and the gate terminal of the TFTs, and a pixel electrode made of a transparent conductive material is connected to the drain terminal.

The second substrate 414 is a color filter substrate in which RGB pixels for implementing colors are formed in a thin film form. For example, the second substrate 414 is made of glass. The common electrode made of a transparent conductive material is formed on the second substrate 414.

In the liquid crystal display panel 410 having such a configuration, when power is applied to the gate terminal of the TFT and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode. The arrangement of the liquid crystal molecules of the liquid crystal layer 416 interposed between the first substrate 412 and the second substrate 414 is changed by the electric field, and is supplied from the flat fluorescent lamp 100 according to the change in the arrangement of the liquid crystal molecules. The transmittance of light to be changed is displayed to display an image of a desired gray scale.

The driving circuit unit 420 may include a data printed circuit board 422 for supplying a data driving signal to the liquid crystal display panel 410, a gate printed circuit board 424 for supplying a gate driving signal to the liquid crystal display panel 410, and data printing. A data driving circuit film 426 connecting the circuit board 422 to the liquid crystal display panel 410, and a gate driving circuit film 428 connecting the gate printed circuit board 424 to the liquid crystal display panel 410. . The data driving circuit film 426 and the gate driving circuit film 428 are made of, for example, a tape carrier package (TCP) or a chip on film (COF). Meanwhile, the gate printed circuit board 424 may be removed by forming separate signal wirings on the liquid crystal display panel 410 and the gate driving circuit film 428.

On the other hand, the liquid crystal display device 300 further includes a storage container 310 for accommodating the flat panel fluorescent lamp 100 and an inverter 320 for generating a discharge voltage for emitting the flat panel fluorescent lamp 100.

The storage container 310 includes a bottom portion 312 and a side portion 314 extending from an edge of the bottom portion 312 to form a storage space for accommodating the flat fluorescent lamp 100. The side portion 314 is, for example, has a structure bent in two stages to provide a coupling space with other components and to improve the bonding force. That is, the side portion 314 extends upwardly from the bottom portion 312 and then has a structure that is bent in parallel with the bottom portion 314 and then bent downwardly. The storage container 310 is made of, for example, a metal having high strength and low deformation.

Inverter 320 outputs a discharge voltage by boosting the low-voltage alternating voltage applied from the outside to a high-potential alternating voltage suitable for light emission of flat plate fluorescent lamp 100. The discharge voltage generated from the inverter 320 is applied to the electrode of the flat plate fluorescent lamp 100 through the first power line 322 and the second power line 324.

The liquid crystal display 300 further includes at least one optical sheet 210 disposed on the diffusion plate 200. The optical sheet 210 changes the path of the light diffused through the diffusion plate 200 once again to improve luminance characteristics. The optical sheet 210 may include a light collecting sheet for condensing the light diffused through the diffusion plate 200 in the front direction to improve the front brightness of the light. In addition, the optical sheet 210 may include a diffusion sheet for diffusing the light diffused through the diffusion plate 200 once again. Meanwhile, the liquid crystal display 300 may further include an optical sheet having various functions according to required luminance characteristics.

The liquid crystal display device 300 further includes an insulating member 350 disposed between the storage container 310 and the flat panel fluorescent lamp 100. The insulating member 350 is disposed to correspond to the edge of the flat fluorescent lamp 100, and the flat fluorescent lamp 100 is spaced apart from the storage container 310 by a predetermined distance to the flat fluorescent lamp 100 and the storage container 310. Shut off electrical contact between the liver. The insulating member 350 is made of a material having a certain degree of elasticity in order to absorb an impact applied from the outside. The insulating member 350 is made of, for example, silicon material to insulate and buffer the flat fluorescent lamp 100. The insulating member 350 is composed of two pieces having a "c" shape. In contrast, the insulating member 350 may be formed of four pieces corresponding to each side of the flat fluorescent lamp 100, or may be formed of four pieces corresponding to four corners of the flat fluorescent lamp 100, or may have a frame shape. It can be formed integrally with.

The liquid crystal display device 300 may include a first mold 330 disposed between the planar fluorescent lamp 100 and the diffusion plate 200, and a second mold disposed between the optical sheet 210 and the liquid crystal display panel 410. 340) further.

The first mold 330 fixes the edge of the flat fluorescent lamp 100 and supports the edge of the diffusion plate 200. As shown, the first mold 330 is integrally formed in a frame shape. Alternatively, the first mold 330 may be composed of two pieces having a "c" or "a" shape, or may have a structure divided into four pieces corresponding to each side.

The second mold 340 fixes the edges of the diffusion plate 200 and the optical sheet 210 and supports the edges of the liquid crystal display panel 410. Like the first mold 330, the second mold 340 may be integrally formed in a frame shape or may have a structure divided into two or four pieces.

The liquid crystal display 300 further includes a top chassis 360 for fixing the display unit 400. The top chassis 360 is coupled to the storage container 310 to fix the edge of the liquid crystal display panel 410. At this time, the data printed circuit board 422 is bent by the data driving circuit film 426 and fixed to the side or bottom of the storage container 310. The top chassis 360 is, for example, made of a metal with little deformation and excellent strength.

According to such a flat panel fluorescent lamp and a liquid crystal display device having the same, by forming a diffuser plate supporting part on the second substrate, the deflection of the diffuser plate is prevented and the distance between the diffuser plate and the flat plate fluorescent lamp is kept constant to improve appearance quality. It can improve and prevent the damage of a flat plate fluorescent lamp.

In addition, the appearance quality can be improved by forming the diffusion plate support between the discharge spaces so that the diffusion plate support is not visible from the outside, and by forming the same as the transparent glass as the second substrate.

Furthermore, by forming the diffusion plate support part integrally with the second substrate during the molding process of the second substrate, the diffusion plate support part can be prevented from being separated from the second substrate.                     

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (10)

A first substrate; A second substrate coupled to the first substrate to form discharge spaces spaced at regular intervals from each other, and a second substrate having at least one diffuser plate support portion formed correspondingly between the discharge spaces to support a diffuser plate disposed thereon; ; And And a electrode formed on an outer surface of at least one of the first substrate and the second substrate to intersect the discharge spaces. The method of claim 1, wherein the second substrate is Discharge space parts spaced apart from the first substrate to form the discharge spaces; Space dividing portions disposed between the discharge space portions and dividing the discharge spaces in contact with the first substrate; And And a sealing unit positioned at an edge of the second substrate and coupled to the first substrate. The flat panel fluorescent lamp of claim 2, wherein the diffusion plate support part is formed in the space division part. 4. The flat fluorescent lamp of claim 3, wherein the diffusion plate support has a conical shape having a predetermined height. The flat panel fluorescent lamp of claim 3, wherein the diffusion plate support part is made of the same material as the second substrate, and is formed at the same time during the molding process of the second substrate. The flat panel fluorescent lamp of claim 3, wherein the diffusion plate support part is made of the same material as the second substrate and adhered to the second substrate. First substrate, A second substrate coupled to the first substrate to form discharge spaces spaced apart from each other at a predetermined interval, and having at least one diffuser plate support portion formed correspondingly between the discharge spaces, and A planar fluorescent lamp comprising an electrode formed on an outer surface of at least one of the first substrate and the second substrate to intersect the discharge spaces; A diffusion plate disposed on the flat plate fluorescent lamp and supported by the diffusion plate support unit; And a liquid crystal display panel disposed on the diffusion plate and displaying an image using light supplied from the flat fluorescent lamp. The method of claim 7, wherein the second substrate Discharge space parts spaced apart from the first substrate to form the discharge spaces; Space dividing portions disposed between the discharge space portions and dividing the discharge spaces in contact with the first substrate; And Located at the edge of the second substrate, including a sealing portion coupled to the first substrate, And the diffusion plate support part is formed in the space division part. The liquid crystal display device of claim 8, wherein the diffusion plate support part is made of the same material as the second substrate, and is formed at the same time as the forming process of the second substrate. The method of claim 7, wherein A storage container accommodating the flat fluorescent lamp; An inverter for generating a discharge voltage for emitting light of the plate fluorescent lamp; A first mold fixing an edge of the plate fluorescent lamp and supporting an edge of the diffusion plate; And And a second mold fixing an edge of the diffusion plate and supporting an edge of the liquid crystal display panel.

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