KR101225255B1 - Lamp and Back Light Unit Using That - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly, to a lamp and a backlight unit using the same that improve light efficiency and enable a liquid crystal display device having a compact structure.

This lamp has a flat light emitting surface, and a reflective layer is formed on all or part of the light except for the light emitting surface.

The backlight unit includes a lamp in which a light emitting surface is flat and a reflection layer is formed on all or part of the light emitting surface except for the light emitting surface, a light guide plate for converting light incident from the lamp into a planar light source, and a light guide plate positioned below the light guide plate. Reflecting plate for reflecting the light beam traveling to the lower surface toward the upper surface, and the optical sheet for controlling the diffusion and propagation direction of the light beam through the light guide plate.

Description

Lamp and Back Light Unit Using That}

1 is a view showing a conventional backlight unit.

2 shows a backlight unit according to a first embodiment of the present invention;

3 is a view illustrating a lamp of the backlight unit of FIG. 2.

4 is a view illustrating a fastening structure of the backlight unit of FIG. 2.

5 is a perspective view of FIG. 4.

6 shows a second embodiment of the present invention;

7A and 7B show another example of a lamp cross section.

DESCRIPTION OF THE RELATED ART [0002]

101, 201, 202: lamp 102: reflective layer

103: light guide plate 104: optical sheet

105: reflector

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly, to a backlight unit that improves light efficiency and enables a liquid crystal display device having a compact structure.

In general, the liquid crystal display device has a trend that the application range is gradually widened due to the characteristics such as light weight, thin, low power consumption. In accordance with this trend, liquid crystal displays have been used in office automation equipment, audio / video equipment, and the like. In such a liquid crystal display device, a transmission amount of a light beam is adjusted according to a signal applied to a plurality of control switches arranged in a matrix to display a desired image on a screen.

Since the liquid crystal display is not a self-luminous display, a separate light source such as a back light unit is required.

The backlight unit is classified into an edge type and a direct type according to the position where the light source is installed. Among the edge type backlight units, a light source is installed at one or both edges, and the light incident from the light source is applied to the light guide plate and a plurality of optical elements. The sheet is irradiated to the liquid crystal display panel through the sheet.

1 is a view showing a lamp installed in a conventional edge type backlight unit.

Referring to FIG. 1, the emitting surface 21 of the lamp 11 is circular, and light incident on the incident surface 23 of the light guide plate 13 directly from the emitting surface 21 of the lamp 11, That is, the remaining light except for the vertical incident light 23 and the inclined incident angle 24 is lost. In order to reduce the loss of light, the lamp housing 12 is attached to the reflecting plate, but the light is also lost due to the reflecting plate. This loss of light is directly linked to problems such as lowering of luminance and loss of power.

Accordingly, an object of the present invention is to provide a lamp and a backlight unit using the same that can increase the light efficiency.

In order to achieve the above object, the lamp according to the embodiment of the present invention has a flat light emitting surface, the reflective layer is formed on all or part except the light emitting surface.

According to an embodiment of the present invention, a backlight unit includes a lamp in which a light emitting surface is flat and a reflection layer is formed on all or part of the light emitting surface except for the light emitting surface, a light guide plate for converting light incident from the lamp into a planar light source, and a light guide plate. A reflecting plate positioned below and reflecting the light beam traveling to the lower surface of the light guide plate toward the upper surface, and optical sheets for controlling the diffusion and the propagation direction of the light beam through the light guide plate.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 2 to 7B.

Referring to FIG. 2, the backlight unit according to the first exemplary embodiment includes a lamp 101, which is a light source, a light guide plate 103 that converts light incident from the lamp 101 into a planar light source, and a light guide plate 103. A reflecting plate 105 positioned at a lower portion of the light guide plate 103 to reflect the light beam traveling to the lower surface of the light guide plate 103 toward the upper surface thereof, and optical sheets 104 for controlling the diffusion and propagation direction of the light beam passing through the light guide plate 103. Equipped.

The liquid crystal display panel 130 that receives the light from the backlight unit and displays the screen on the optical sheets 104 faces the optical sheets 104. In the liquid crystal display panel 130, a plurality of data lines and a plurality of scan lines are arranged to cross each other, and liquid crystal cells are arranged in an active matrix form between the upper substrate 131 and the lower substrate 132. In addition, the liquid crystal display panel 130 includes pixel electrodes and a common electrode for applying an electric field to each of the liquid crystal cells. TFTs for switching data voltages to be applied to the pixel electrodes are formed at intersections of the plurality of data lines and the plurality of scan lines. Scan drive integrated circuits and data drive integrated circuits are electrically connected to the liquid crystal display panel.

The manufacturing process of the liquid crystal display panel 130 is divided into a substrate cleaning process, a substrate patterning process, an alignment film forming / rubbing process, a substrate bonding / liquid crystal injection process, a mounting process, an inspection process, a repair process, and the like. In the substrate cleaning process, foreign substances contaminated on the substrate surface are removed with a cleaning liquid. In the substrate patterning process, the upper substrate (color filter substrate) of the liquid crystal display panel is divided into the patterning of the lower substrate (TFT-array substrate). A color filter, a common electrode, a black matrix, and the like are formed on the upper substrate. Signal lines such as data lines and gate lines are formed on the lower substrate, and TFTs are formed at intersections of the data lines and gate lines, and pixel electrodes are formed in the pixel region between the data lines and gate lines connected to the source electrodes of the TFTs. Is formed. In the alignment film formation / rubbing process, an alignment film is applied to each of the upper substrate and the lower substrate, and the alignment film is rubbed with a rubbing cloth or the like. In the substrate bonding / liquid crystal injection process, the upper substrate and the lower substrate are bonded using a sealant, the liquid crystal and the spacer are injected through the liquid crystal inlet, and then the liquid crystal inlet is sealed. In the mounting process of the liquid crystal display panel 130, TCP in which integrated circuits such as a gate drive integrated circuit and a data drive integrated circuit are mounted is connected to a pad portion on a substrate. The drive integrated circuit may be directly mounted on a substrate by a chip on glass (COG) method in addition to the tape automated bonding method using the above-described TCP. The inspection process includes an electrical inspection performed after various signal wiring and pixel electrodes are formed on the lower substrate, and an electrical inspection and a visual inspection performed after the substrate bonding / liquid crystal injection process. The repair process restores the substrate that is determined to be repairable by the inspection process. A module in which a printed circuit board (PCB), a case / chassis member, and a backlight unit as shown in FIG. 2 is assembled together with the liquid crystal display panel 130 completed by such a process is generally referred to as a liquid crystal display module.

Electrodes formed of a conductor are provided at both ends of the lamp 101, and an inert gas is injected therein. Phosphors are formed inside the emission surface 121 of the lamp 101 formed in a plane, and the reflective layer 102 is formed on all or part of the portion except the emission surface. The reflective layer 102 is formed on the outer surface or the inner surface of the lamp, and when formed on the inner surface, may be formed of a material such as barium oxide or magnesium oxide. In this way, the exit surface 121 of the lamp 101 facing the entrance surface 122 of the light guide plate 103 is planar, so that the light beam incident from the exit surface 121 to the entrance surface 121 can be seen in FIG. 3. As described above, the light beam component includes a light beam component perpendicular to the incident surface 121. The reflective layer 102 reduces light loss by rereflecting the light incident on the light guide plate 103 toward the light guide plate 103.

The lamp 101 may be implemented by a Cold Cathode Fluorescent Lamp (CCFL) method. The CCFL method uses a fluorescent discharge tube encapsulated at low pressure with a mercury gas containing argon, neon, or the like to take advantage of the penning effect. Electrodes are formed at both ends of the tube, and the cathode is formed in a wide plate shape.When voltage is applied, as in the sputtering phenomenon, charged particles in the discharge tube collide with the plate-shaped cathode to generate secondary electrons, which excite surrounding elements to excite the plasma. To form. These elements emit strong ultraviolet rays, which in turn excite the phosphors formed inside the exit surface 121 to cause the phosphors to emit visible light.

In addition, the lamp 101 may be implemented in various ways, such as CCFL as well as External Electrode Fluorescent Lamp (EEFL) and Flat Fluorescent Lamp (FFL).

The light guide plate 103 is manufactured by injection molding with a mold, scattering pattern printing, or the like. The light guide plate 103 converts light incident from the lamp 101 through the incident surface into a planar light source and emits the light toward the liquid crystal panel.

The reflective plate 105 serves to reduce light loss by reflecting light incident to itself through the rear surface of the light guide plate 103 toward the light guide plate 103. That is, the reflector plate 105 reflects light incident on the light guide plate 103 and traveling to the rear surface of the light guide plate 103 toward the front surface.

The optical sheets are composed of a diffusion sheet for diffusing a light beam through the light guide plate 103 and a prism sheet for adjusting a traveling direction of the light beam. The diffusion sheet and the prism sheet may be used in several sheets depending on their needs.

4 illustrates a fastening structure of the lamp 101 and the light guide plate 103.

Referring to FIG. 4, protrusions 107b and grooves 109 are formed at ends of the lamps, and electrodes 106 protrude from the protrusions 107b. A hole 107a for fastening with the protrusion 107b of the lamp and a hook 108 for fastening with the groove 109 of the lamp are formed in the extension of the side of the light guide plate 103. In addition, a coupling member 107c which bends the lamp is formed at the upper edge of the light guide plate. The coupling member 107c may be installed at the middle or both ends as necessary, and may be installed at least one.

5 illustrates a top perspective view and a side cross-sectional view of the coupling member 107c after the lamp 101 and the light guide plate 103 of FIG. 4 are fastened.

6 shows a backlight unit according to a second embodiment of the present invention. Unlike the first embodiment, the backlight unit in the second embodiment is provided with lamps on both sides of the light guide plate 103. Except for this difference, the same description as in the first embodiment will be omitted.

On the other hand, the lamp constituting the backlight unit in the first and the second embodiment has an example that the cross section is in the form of a quadrangle as shown in FIG. The lamp can also be of any other shape with a flat exit surface.

As described above, the lamp according to the present invention and the backlight unit using the same have the effect of reducing the light loss by improving the light use efficiency and brightness by using a lamp having a flat emitting surface. In addition, since the lamp is fixed to one side of the light guide plate stably by the fastening part extended from the side of the light guide plate, the process for the lamp housing is reduced, thereby providing a backlight unit having a compact structure and reducing the cost. Have

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the 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 (17)

The light exit plane is flat, The reflective layer is formed on all or part of the exit surface, At least one groove for fastening with an external device. The method of claim 1, The reflective layer is characterized in that the lamp is formed on the outer surface. The method of claim 1, The reflecting layer is a lamp, characterized in that formed on the inner surface. The method of claim 1, Both ends include a projection protruding outward for fastening with the external device, the lamp further comprises an electrode protruding from the projection. The method of claim 3, wherein And the reflective layer is formed of barium oxide or magnesium oxide. The method of claim 1, A lamp, characterized in that the cross section is square. The method of claim 1, A lamp, characterized in that the cross section is semicircular. A lamp in which the light emitting surface is planar and a reflective layer is formed on all or part of the light emitting surface except for the light emitting surface; A light guide plate for converting light incident from the lamp into a planar light source; A reflecting plate positioned under the light guide plate and reflecting a light beam traveling toward the lower surface of the light guide plate toward the upper surface; Optical sheets for controlling the diffusion and propagation direction of the light beam through the light guide plate; And the lamp has at least one groove for fastening with the light guide plate. 9. The method of claim 8, And the reflective layer is formed on an outer surface of the lamp. 9. The method of claim 8, And the reflective layer is formed on an inner surface of the lamp. 9. The method of claim 8, The light guide plate includes an extension part extended to both ends of the lamp for fastening with the lamp. 11. The method of claim 10, And the reflective layer is formed of barium oxide or magnesium oxide. 9. The method of claim 8, And a cross section of the lamp is a rectangle. 9. The method of claim 8, And a cross section of the lamp is semicircular. The method of claim 11, The lamp further comprises a projection for fastening with the extension of the light guide plate. 16. The method of claim 15, The light guide plate includes a hook for fastening with the groove; And a groove for fastening with the protrusion. 9. The method of claim 8, The upper edge of the light guide plate further comprises at least one coupling member for fixing with the lamp.

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