KR20070117317A - Lamp printed by a pattern and back light unit using it - Google Patents

Abstract

A pattern printed lamp and a backlight unit using the same are provided to scatter the light emitted from the lamp through a pattern printed on a lower end of a glass tube of the lamp. A pattern printed lamp has a glass tube(132) having a circular cross section, both ends of the glass tube being airtightly sealed by lead wires(130,131). The glass tube is made of borosilicate glass, and a pattern(137) is formed on the lower end of the glass tube. A dot interval of the pattern is gradually increased or decreased towards a side of the glass so as to reduce a brightness difference between a center and side of a lamp.

Description

LAMP PRINTED BY A PATTERN AND BACK LIGHT UNIT USING IT}

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

2 and 3 is a diagram illustrating an embodiment of a general direct type backlight unit.

Figure 4 is a cross-sectional view of one embodiment of a typical cold cathode fluorescent lamp.

5 is a cross-sectional view of an embodiment of a pattern-printing lamp according to the present invention.

Figure 6 is an exemplary view of a pattern applied to the pattern-printing lamp according to the present invention.

7 is an exemplary view illustrating a light emission state of a backlight unit using a pattern printing lamp according to the present invention.

8 is an exemplary view showing a light emission state of a backlight unit using a pattern printing lamp according to the present invention.

<Explanation of symbols for main parts of the drawings>

100: pattern printing lamp (100) 130, 131: lead wire

132: glass tube 137: pattern

134: fluorescent film 135: mixed gas

136, 138: electrode 217: lamp housing

212: Light guide plate 211: Reflector plate

219: Pattern 213: Diffusion sheet

214, 215: prism sheet 321: cover bottom

322: reflector 329: optical sheet portion

324 diffusion plate 325 diffusion sheet

326: prism sheet 327: reflective polarizing film

The present invention relates to a pattern printing lamp and a backlight unit using the same.

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 device may be classified into a liquid crystal panel displaying an image that is largely displayed to a user, and a backlight unit for increasing 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 exemplary edge type backlight unit.

That is, the edge type backlight unit illustrated in FIG. 1 includes a light emitting unit including a lamp 18 and a lamp housing 17, and a light guide panel (LGP) 12 for generating a uniform light distribution on the liquid crystal panel. And a reflecting plate 11, wherein the optical sheet portions such as the diffusion sheets 13 and 16 and the prism sheets 14 and 15 are used to adjust the direction of light emitted through the light guide plate 12 and to secure a desired viewing angle. The light guide plate 12 is disposed between the liquid crystal panel.

In this case, as shown in FIG. 1, the edge type backlight unit is scattered as the light emitted from the lamp 18 hits the pattern 19 formed on the light guide plate and exits toward the liquid crystal panel through the top sheet. As a result, the amount of light directed toward the liquid crystal panel is reduced.

On the other hand, although the light emitted from the lamp 18 is scattered while being hit by the pattern 19 of the light guide plate 12, some of the light emitted from the lamp 18 is emitted in the opposite direction (a) of the light guide plate Since it is scattered and reflected by the lamp housing 17 to be incident on the light guide plate 12, there is a problem that the amount of light incident on the light guide plate 12 itself is reduced among the total amount of light emitted from the lamp 18.

2 and 3 are diagrams illustrating one embodiment of a general direct type backlight unit.

That is, the general direct type backlight unit as shown in FIGS. 2 and 3 includes a cover bottom 21 on a plate made of a metal or a synthetic resin material, and a white or silver metal seated on the cover bottom. It comprises a reflector 22 on a plate made of a material, a plurality of lamps 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, the general direct-backlit backlight unit illustrated in FIGS. 2 and 3 implements high brightness by connecting a plurality of lamps in parallel, but there is a problem in that the lamp is scattered through the reflector because the lamp is a linear light source. Moreover, since some of the light emitted from the lamp is emitted toward the reflecting plate 22 side (b) at the bottom of the lamp and then reflected by the reflecting plate 22 and toward the liquid crystal panel at the upper end of the lamp, from the lamp 23 Among the total amount of light emitted, there is a problem in that the amount directed toward the liquid crystal panel is reduced.

Meanwhile, a cold cathode fluorescent lamp is generally used as the lamps 18 and 23 used as light sources in the edge backlight and the direct backlight, and the general structure of the cold cathode fluorescent lamp is shown in FIG. 4.

4 is a cross-sectional view of an exemplary cold cathode fluorescent lamp according to one embodiment, and is taken along a length of the lamp 39.

The cold cathode fluorescent lamp 39 has a substantially circular cross section, and includes a glass tube 32 hermetically sealed by lead wires 30 and 31 at both ends.

The inside of the glass tube 32 is filled with a mixed gas 35 containing approximately 3 mg of mercury, and a fluorescent film 34 is formed on the inner surface of the glass tube 32.

The lead wires 30 and 31 are formed by connecting the inner lead wires 30A and 31A made of tungsten and the outer lead wires 30B and 31B made of nickel, and the inner lead wires 30A and 30A are respectively formed of glass tubes 32. Is supported by the end of

The electrodes 36, 38 are coupled to the ends of the inner lead wires 30A, 31A located inside the glass tube 32 by, for example, laser welding.

On the other hand, as described above, the cold cathode fluorescent lamp has no filament coil and can be made thin with a small diameter, and thus is widely used because it satisfies the need for a thin backlight unit of a liquid crystal display device.

However, in order to obtain a high quality image of a liquid crystal display (LCD), it is further required that such a backlight unit has a high brightness. As a method for obtaining a high brightness in the backlight unit, a cold cathode fluorescent lamp is driven with an increased lamp current. You can think of it. According to this method, however, the luminous flux of the cold cathode fluorescent lamp increases to some extent, but as the current of the cold cathode fluorescent lamp increases, the cold spot temperature increases and exceeds the optimum range. There is a problem that decrease.

As another method, if a thicker lamp is used to improve heat dissipation with an increase in lamp current, an excessive increase in the cold spot temperature will be prevented. According to this method, however, especially when the inner diameter is increased, the distance between the tube inner wall and the center of the positive light plasma space increases, which reduces the luminous efficiency and does not increase the luminous flux as expected in response to the increase in the lamp current. There is a problem. In addition, since the backlight unit has a limited space for accommodating the lamp, if a thicker lamp is used for such a backlight unit than the conventional one, the part of the light emitting surface closer to the lamp has a higher luminance and a part further away from the lamp. So-called "non-uniform brightness" with lower brightness occurs (hereinafter, this non-uniform brightness is referred to as "unstable and non-uniform brightness"). This problem can be solved by making the receiving space thicker and the lamps aligned at a constant distance from the emitting surface. However, this method is not practical because, as mentioned above, the demand for a thin backlight unit is strong.

Accordingly, an object of the present invention for solving the above problems is a pattern-printing lamp in which a pattern is formed at the lower end of the lamp to increase the amount of light emitted from the lamp and reflected toward the liquid crystal panel through the sheet; It is to provide a backlight unit using the same.

In order to achieve the above object, the pattern-printing lamp according to an embodiment of the present invention, the glass tube is hermetically sealed; And a pattern formed in a length direction of the glass tube on one side of the inside of the glass tube.

According to an embodiment of the present invention, a backlight unit using a pattern printing lamp includes a pattern printing lamp including a glass tube that is hermetically sealed and a pattern formed in a length direction of the glass tube on one side of the glass tube; A lamp housing for protecting the lamp; A light guide plate formed in the longitudinal direction of the lamp to make light emitted from the lamp into a uniform surface light source; A reflector disposed on a rear surface of the light guide plate; And optical sheets disposed on the light guide plate to diffuse light emitted from the light guide plate to improve brightness of the light.

In addition, the pattern is characterized in that formed on the inner surface of the opposite side of one side of the glass tube in contact with the light guide plate.

According to another embodiment of the present invention, a backlight unit using a pattern printing lamp includes: a cover bottom; A plate-shaped reflector plate mounted on the cover bottom and made of a metal material; A plurality of lamps arranged in parallel on the reflecting plate; And optical sheets seated on top of the plurality of lamps, each of the plurality of lamps including a hermetically sealed glass tube and a pattern formed in the longitudinal direction of the glass tube on one side of the glass tube. It is characterized in that the pattern printing lamp.

In addition, the pattern is characterized in that formed on the inner surface of one side of the glass tube in contact with the reflecting plate.

In addition, the pattern is characterized in that the densely formed to the side of the glass tube.

In addition, the glass tube is characterized in that the glass tube of the cold cathode fluorescent lamp.

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

5 is a cross-sectional view of an embodiment of a pattern-printing lamp according to the present invention, in particular a longitudinal cross-sectional view cut along the length of a cold cathode fluorescent lamp (hereinafter, simply referred to as a 'lamp') 100. 6 is an exemplary view of a pattern applied to a pattern printing lamp according to the present invention.

That is, the pattern-printing lamp 100 according to the present invention includes a glass tube 132 having a substantially circular cross section and hermetically sealed by lead wires 130 and 131 at both ends.

First, the glass tube 132 is composed of rigid borosilicate glass, with a total length of 450 mm, an outer diameter of 4.0 mm and an inner diameter of 3.0 mm. At this time, a pattern 137 as shown in FIG. 6 is formed at the lower end of the glass tube 132. On the other hand, the shape and material of the pattern 137 may be variously selected, and in particular, in order to reduce the luminance deviation between the center and the side of the lamp, the side of the glass tube 132 as shown in FIG. Towards this point, the dot spacing of the pattern can be widened or the dot size of the pattern can be reduced. In other words, In view of the fact that the brightness of the side is lower than that of the center of the lamp, the present invention reduces the luminance deviation of the center and the side by providing a deviation in the pattern dot size and dot spacing between the center and the side of the lamp. The overall brightness of the lamp can be made uniform.

In addition, a fluorescent film 134 is formed on an inner surface of the glass tube 132, and the fluorescent film 134 includes three rare earth fluorescent materials. That is, the fluorescent layer 134 may include a red phosphor (Y 2 O 3: Eu 3+), a green phosphor (LaPO 4: Ce 3+, Tb 3+), and a blue phosphor (BaMg 2 Al 16 O 27: Eu 2+).

The glass tube 132 is also filled with a mixed gas 135 containing approximately 3 mg of mercury.

In addition, the lead wires 130 and 131 are formed by connecting the inner lead wires 130A and 131A made of tungsten and the outer lead wires 130B and 131B made of nickel, and the glass tube 132 has an inner lead wire (from both ends). 128A, 130A). At this time, the cross sections of the inner lead wires 130A and 131A and the outer lead wires 130B and 131B are circular, and the inner lead wires 130A and 131A are respectively supported by the ends of the glass tube 132. The diameters of the inner lead wires 130A, 131A are each 1 mm, the total length is 3 mm, the diameters of the outer lead wires 130B, 131B are respectively 0.8 mm, and the total length is 10 mm.

In addition, the electrodes 136 and 138 are hollow and have a cylindrical shape with a bottom, and are made of niobium bars. For example, by laser welding, at the ends of the inner lead wires 130A and 131A located inside the glass tube 132. Each combined. The reason why the hollow type is adopted for the electrodes 136 and 138 as described above is that the hollow type is effective in suppressing sputtering at the electrode caused by the discharge when the lamp is turned on. At this time, the electrode has dimensions of electrode length 5.2mm, outer diameter 2.7mm, thickness 0.2mm (inner diameter 2.3mm), the center of which is arranged to be the tube axis of the glass tube 132, the discharge is hollow when the lamp is turned on It occurs only inside the electrodes 136 and 138.

That is, in the pattern printing lamp according to the present invention having the above configuration, since the light generated by the discharge by the electrodes 136 and 138 can be reflected by the pattern 137 only in a specific direction, As shown in FIG. 7 and FIG. 8, it may be used as a lamp of the backlight unit of the liquid crystal display.

7 is an exemplary view showing a light emitting state of a backlight unit using a pattern-printing lamp according to the present invention, in particular showing the light emitting state of the edge type backlight unit. Edge type backlight unit according to the present invention is largely composed of a light emitting portion, a waveguide portion and an optical sheet portion as shown in FIG.

First, the light emitting unit includes a lamp 100 and a lamp housing 217 for protecting the lamp. In this case, the lamp 100 is a pattern-printing lamp according to the present invention mentioned in the description of Figures 5 and 6 used.

In addition, the waveguide is located on a light guide panel 212 that makes the light emitted from the lamp 100 into a uniform surface light source, and is disposed on the rear surface of the light guide plate to reflect the light emitted from the lamp to concentrate toward the liquid crystal panel (front). It consists of a reflecting plate 211 to serve to prevent the loss of light from the back or side of the light guide plate. In this case, various patterns 219 are formed on the rear surface (bottom surface) of the light guide plate to reflect the light emitted from the lamp 100 to be concentrated toward the liquid crystal panel side (front surface). Can be.

In addition, the optical sheet unit is located on the light guide plate to diffuse the light emitted from the light guide plate (diffuser sheet) 213 to improve the brightness of the light, located on the diffuser sheet to collect light from the light guide plate to increase the viewing angle A prism sheet (214, 215) to enhance and a protector sheet (216) to prevent damage to the diffusion sheet and prism sheet while at the top layer of the backlight unit to secure the desired viewing angle. Consists of.

That is, in the backlight unit using the pattern-printing lamp according to the present invention as shown in FIG. 7, light emitted from the lamp 100 is positioned in the light guide plate by the pattern 137 formed in the glass tube 132 of the lamp. Because it reflects more light, more light can be focused toward the liquid crystal panel (front).

8 is an exemplary view showing a light emitting state of a backlight unit using a pattern-printing lamp according to the present invention, in particular showing the light emitting state of the direct type backlight unit.

That is, the direct type backlight unit using the pattern-printing lamp according to the present invention is mounted on a cover bottom (321), a cover bottom of a plate made of metal or synthetic resin material, as shown in FIG. It comprises a reflector plate (322) of a plate made of a silver metal material, a plurality of lamps 100 arranged in parallel on the reflecting plate and an optical sheet portion 329 seated on the plurality of lamps have.

In this case, as the lamp 100, the pattern-printing lamp according to the present invention mentioned in the description of Figs. 5 and 6 is used.

In addition, the optical sheet part 329 includes a diffusion plate 324 seated on the vertical top of the lamp, a diffusion sheet 325 seated on the top of the diffusion plate, a prism sheet 326 seated on the top of the diffusion sheet, and It is configured to include a reflective polarizing film (MOF) 327 of a multi-layer structure is mounted on the top of the prism sheet.

Meanwhile, a liquid crystal panel (not shown) manufactured through a separate process is mounted on the upper end of the optical sheet unit 329, 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.

 That is, as shown in Figure 8, the backlight unit using a pattern printing lamp according to the present invention, the light emitted from the lamp 100 by the pattern 137 formed in the glass tube 134 of the lamp, the reflection plate It can be reflected directly to the liquid crystal panel side (front side) without being irrelevant, and has the characteristic that more light can be focused to a liquid crystal panel side (front side).

In addition, the present invention, as described above, by forming a pattern of different dot spacing or dot size in the center and the side of the lamp 100, the luminance difference between the side and the center of the lamp 100 is reduced, more uniform It has the feature of emitting light of luminance.

Meanwhile, the present invention has been described with the cold cathode fluorescent lamp as an example, but the present invention is not limited thereto, and thus, the present invention can be applied to various kinds of lamps used in the backlight unit. According to the present invention, a light reflecting pattern may be formed on one surface of a lamp used in the backlight unit so that the light emitted from the lamp may travel only in a specific direction.

In the pattern printing lamp and the backlight unit using the same according to the present invention as described above, the light emitted from the lamp is scattered by the printing pattern of the glass tube by printing a pattern on the lower end of the lamp glass tube, so that the amount of light exits toward the liquid crystal panel. It has the effect of increasing the.

In addition, the present invention has an effect that the luminance variation between the center and the side of the lamp can be reduced by arranging the dot size or the dot spacing of the pattern for each center and side of the lamp.

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 hermetically sealed glass tube; And Pattern printing lamp comprising a pattern formed in the longitudinal direction of the glass tube on one side inside the glass tube. The method of claim 1, The pattern is a pattern-printing lamp, characterized in that the pattern is densely formed to go to the side of the glass tube. The method of claim 1, The glass tube is a pattern printing lamp, characterized in that the glass tube of the cold cathode fluorescent lamp. A pattern-printing lamp comprising a glass tube hermetically sealed and a pattern formed on one side of the glass tube in a longitudinal direction of the glass tube; A lamp housing for protecting the lamp; A light guide plate formed in the longitudinal direction of the lamp to make light emitted from the lamp into a uniform surface light source; A reflector disposed on a rear surface of the light guide plate; And The backlight unit using a pattern-printing lamp positioned on the light guide plate and including optical sheets for diffusing the light from the light guide plate to improve the brightness of the light. The method of claim 4, wherein The pattern is a backlight unit using a pattern-printing lamp, characterized in that formed on the inner surface of one side opposite to the one side of the glass tube in contact with the light guide plate. A cover bottom; A plate-shaped reflector plate mounted on the cover bottom and made of a metal material; A plurality of lamps arranged in parallel on the reflecting plate; And It includes optical sheets seated on top of the plurality of lamps, Each of the plurality of lamps is a backlight using a pattern-printing lamp comprising a glass tube that is hermetically sealed and a pattern formed in a length direction of the glass tube on one side of the glass tube. unit. The method of claim 6, The pattern unit is a backlight unit using a pattern-printing lamp, characterized in that formed on the inner surface of one side of the glass tube in contact with the reflecting plate. The method according to any one of claims 4 to 6, The pattern is a backlight unit using a pattern-printing lamp, characterized in that the pattern is densely formed to go to the side of the glass tube. The method according to any one of claims 4 to 6, The glass tube is a backlight unit using a pattern-printing lamp, characterized in that the glass tube of the cold cathode fluorescent lamp.

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