KR20060099884A - Back light assembly and liquid crystal display module using thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight assembly having a lamp housing which bears the fluorescent lamp in a longitudinal direction so that light emitted from the fluorescent lamp is concentrated on the side of a light guide panel, and a liquid crystal display module using the same.

More specifically, the present invention provides a light guide plate having at least one fixing groove biased toward at least one side; A fluorescent lamp arranged along the at least one side length direction of the light guide plate; A lamp housing in which an upper end is inserted into the fixing groove and a lower end bears the fluorescent lamp in its inner longitudinal direction toward the lower end of the at least one side of the light guide plate; Providing a backlight assembly for a liquid crystal display device including a plurality of optical sheets covering the light guide plate, wherein the liquid crystal panel is mounted on the optical sheet as a liquid crystal display module using the same; A support main frame that surrounds the backlight assembly and the liquid crystal panel; A cover bottom covering the bottom of the light guide plate; Provided is a liquid crystal display module including a top cover bordering a front edge of the liquid crystal panel.

As a result, there is an advantage in that the fixing state of the lamp housing can be maintained closely without using a separate fixing member such as a double-sided tape.

Description

Back light assembly and liquid crystal display module using the same

1 is an exploded perspective view of a typical liquid crystal display module.

2 is a partial cross-sectional view of a general liquid crystal display module.

3 is an exploded perspective view of a liquid crystal display module according to the present invention.

FIG. 4 is an enlarged view of portion A of the circle of FIG. 3; FIG.

5 is an exploded perspective view of a modification of the liquid crystal display module according to the present invention.

6 is a partial cross-sectional view of a liquid crystal display module according to the present invention of FIG.

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

110: support main 120: backlight assembly

122: reflective sheet 124: fluorescent lamp

126: light guide plate 128: optical sheet

130: lamp housing 140: liquid crystal panel

141,143: first and second substrate 144: flexible circuit board

148,148 gate and data driving circuit 150 cover cover

160: top cover 170: fixing groove

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back light assembly for a liquid crystal display device and a liquid crystal display module using the same. More specifically, light emitted from a fluorescent lamp is light guide plate. The present invention relates to a backlight assembly having a lamp housing for guiding the fluorescent lamp in a longitudinal direction so as to be concentrated at a side of a guide panel and a liquid crystal display module using the same.

In recent years, as the society enters the information age in earnest, the display field which visually expresses various electrical signal information has been rapidly developed, and in response to this, various fields having excellent characteristics such as thinning, light weight, and low power consumption have been developed. Various types of flat panel display devices (FPDs) have been introduced to quickly replace the existing cathode ray tubes (CRTs).

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescent display device. (Electroluminescence Display device: ELD), etc. The dual liquid crystal display device has a high contrast ratio and excellent characteristics for moving image display is currently being used most actively in the notebook, monitor, TV field.

A general liquid crystal display device has an image realization principle using optical anisotropy and polarization property of liquid crystal. As is well known, liquid crystal has a thin and long molecular structure and has an optical anisotropy having an orientation in an array and a molecular arrangement depending on its size when placed in an electric field. It is polar in nature with its changing direction.

Accordingly, a liquid crystal display device includes a liquid crystal panel in which a pair of substrates having transparent field generating electrodes are formed on a surface facing each other with a liquid crystal layer interposed therebetween, and a back light assembly for supplying light thereto. ), And by varying the transmittance by artificially adjusting the arrangement direction of the liquid crystal molecules according to the electric field size between the two field generating electrodes of the liquid crystal panel to pass the light emitted from the backlight assembly to the difference in the transmittance Various target images are displayed by making them appear outside.

Recently, the active matrix type, in which pixels, which are basic units of image expression, is arranged in a matrix manner on a liquid crystal panel, and each of them is independently controlled by using a thin film transistor (TFT), is a color. It is widely used because of its excellent reproducibility and video display.In this case, the backlight assembly is used as a light source to generate light, or a cold cathode fluorescent lamp (CCFL) or an external electrofluorescent lamp (EEFL). Is provided.

In general, a backlight assembly for a liquid crystal display device includes a side light type that refracts light of a fluorescent lamp disposed at one edge of a rear side of a liquid crystal panel with a light guide plate and enters the front side of the liquid crystal panel according to an arrangement method of the fluorescent lamp. type) or a direct type for directly supplying light over the entire liquid crystal panel by arranging a plurality of fluorescent lamps on the back of the liquid crystal panel.

1 is an exploded perspective view of a liquid crystal display device including a general light metering backlight assembly. Since the liquid crystal panel 40 and the backlight assembly 20 are usually modularized by mobilizing various mechanical elements, the liquid crystal display device is described below. It is called a module.

As shown, a general liquid crystal display module has an approximately rectangular frame-shaped support main (support main 10) bordering these edges with the liquid crystal panel 40 and the backlight assembly 20 stacked up and down. The cover cover 50 of the role covers the back of the backlight assembly 20 and is coupled to the support main 10 to maintain the overall shape while minimizing light loss and to integrate all of the liquid crystal panels 40. The top frame (top cover: 60) having a rectangular frame shape bordering the front edge is assembled and supported by the support main 10 and the cover bottom 50.

In this case, at least one side of the liquid crystal panel 40 is connected to the driving circuits 44 and 46 via a flexible printed circuit board 42, which is the outer side or the cover bottom of the support main 10 during the assembly process. The back surface of (50) is appropriately folded to be in close contact.

In addition, the backlight assembly 20 may include a white or silver reflective sheet 22 covering the inner surface of the cover bottom 50, and a fluorescent lamp arranged along an inner length direction of at least one edge 12 of the support main 10. And a light guide panel having a predetermined thickness in which at least one side thereof faces the fluorescent lamp 24 by being seated on the reflective sheet 22 so as to have the same plane position as the fluorescent lamp 24. And a plurality of optical sheets 28 covering the light guide plate 26, wherein the light emitted from the fluorescent lamp 24 is concentrated along the length of the light guide plate 26. The lamp housing 30 surrounding the top and bottom three directions is interposed in at least one edge 12 of the support main 10.

In this case, the lamp housing 30 may be formed integrally with the reflective sheet 22 as shown in the drawing. In this case, the end of the reflective sheet 22 facing the fluorescent lamp 24 may be disposed at the outside of the fluorescent lamp 24. It is possible to perform the desired function by bending in two stages inward and upward.

As a result, in the backlight assembly 20 having the above-described configuration, the light emitted from the fluorescent lamp 24 is incident on the light guide plate 26 side by the lamp housing 30 and refracted in the direction of the liquid crystal panel 40. While passing through 28, it is processed into a high quality of uniform brightness and supplied to the liquid crystal panel 40. In this case, as shown in the support main 10, as shown, one edge 12 in which the lamp housing 30 including the fluorescent lamp 24 is interposed may be opened, and the plurality of optical sheets 28 may be prism sheets. (prism sheet) and diffuser sheet (diffuse sheet) and the like.

On the other hand, in the above description, the lamp housing 30 is usually made of the same plastic sheet as the reflective sheet 22, which may leak light between the light guide plate 26 due to its restoring force by its own physical properties. As a result of the gap, as a result, foreign matter penetrates into the lamp housing 30, as well as stains such as bright lines on the display screen due to light leakage through the gap.

Referring to the drawings, FIG. 2 is a view illustrating a portion of the fluorescent lamp 24 and the lamp housing 30 in a typical liquid crystal display module.

Accordingly, as described above, the cover sheet 50 and the reflective sheet 22 interposed therebetween, the light guide plate 26 seated thereon, and the fluorescent lamp 24 arranged along one longitudinal direction of the light guide plate 26. The lamp housing 30 formed integrally with the reflective sheet 22 surrounds the fluorescent lamp 24 and the plurality of optical sheets 28 are covered with the upper part of the light guide plate 26.

At this time, the mounting space of the fluorescent lamp 24 defined by the lamp housing 30 and the light guide plate 26 is sealed so that there is no gap where light may leak, and concentrates the light emitted from the fluorescent lamp 24 to the light guide plate 26 side. The upper end portion of the lamp housing 30 should be kept in close contact with the upper edge of the light guide plate 26.

However, the lamp housing 30 made of a sheet material may have a gap between the upper end portion and the light guide plate 26 as shown by the self-resilience, and thus, the upper end of the lamp housing 30 is currently prevented to prevent this. The portion and the upper edge of the light guide plate 26 are bonded by a separate fixing member such as a double-sided tape 27 or the like.

However, this method of using the double-sided tape 27 requires very close attention and a lot of time since the bonding site is extremely narrow, and shows a problem of cost increase by the double-sided tape 27. Furthermore, the expansion of the lamp housing 30 and the weakening of the adhesive force of the double-sided tape 27 are caused by the heat generated by the long-term operation of the fluorescent lamp 24. As a result, a phenomenon in which a gap occurs frequently without maintaining a close contact state is frequently caused. It is observed.

When such a gap appears, the light generated from the fluorescent lamp 24 is directly incident on the liquid crystal panel (see 40 in FIG. 1) through the gap and the optical sheet 28, so that a bright line appears in the corresponding part. It is a direct cause of deterioration of image quality, and a problem that foreign substances penetrate.

Accordingly, the present invention is to solve the above problems, it is possible to fix the shape of the lamp housing without using a separate fixing member such as double-sided tape, and despite the external factors of heat generation or impact of the fluorescent lamp It is an object of the present invention to provide a backlight assembly for a liquid crystal display device and a liquid crystal display module using the same, which can maintain a fixed state of a lamp housing.

The present invention includes a light guide plate having one or more fixing grooves biased to at least one side top to achieve the above object; A fluorescent lamp arranged along the at least one side length direction of the light guide plate; A lamp housing in which an upper end is fitted into the fixing groove and a lower end bears the fluorescent lamp in its inner length direction toward the lower end of the at least one side of the light guide plate; Provided is a backlight assembly for a liquid crystal display device including a plurality of optical sheets covering the light guide plate.

At this time, the fixing groove is characterized in that the slit shape formed along the longitudinal direction of the upper side of the at least one side of the light guide plate, characterized in that the lower end of the lamp housing is in close contact with the back of the light guide plate, the reflective sheet interposed to the back Characterized in that it further comprises. In this case, the reflective sheet is characterized in that the integral body extending from the lower end of the lamp housing.

The present invention also provides a liquid crystal display module having a backlight assembly as described above, comprising: a liquid crystal panel seated on the optical sheet; A support main frame that surrounds the backlight assembly and the liquid crystal panel; A cover bottom covering the bottom of the light guide plate; Provided is a liquid crystal display module including a top cover bordering a front edge of the liquid crystal panel.

At this time, the lower end of the lamp housing is sandwiched between the light guide plate and the cover bottom, characterized in that it further comprises a reflective sheet interposed between the light guide plate and the cover bottom, the reflective sheet is at the lower end of the lamp housing The present invention will be described in more detail with reference to the accompanying drawings.

3 is an exploded perspective view of the liquid crystal display module according to the present invention. The backlight main assembly 120 and the liquid crystal display assembly 110 of which a support main 110 made of a synthetic resin or a sustain steel mold having a substantially rectangular frame shape is stacked up and down. The cover bottom 150, which borders the edge of the panel 140 and serves to maintain the overall shape and prevent light loss, is coupled to the support main 110 while covering the rear surface of the backlight assembly 120. The top cover 160 bordering the front edge of the panel 140 is coupled to the support main 110 to integrate the whole.

More specifically, first, the liquid crystal panel 140 includes a pair of first and second substrates 141 and 143 bonded to each other with a liquid crystal layer interposed therebetween as a part that plays a key role in image expression.

At this time, although not clearly shown in the drawings, a plurality of gate lines and data lines intersect on the inner surface of the first substrate 141, which is referred to as a lower substrate or an array substrate, to define pixels, and at each intersection point. A thin film transistor (TFT) is provided to correspond one-to-one with a pixel electrode mounted in each pixel. An inner surface of the second substrate 143, called an upper substrate or a color filter substrate, corresponds to each pixel, for example, a color filter of R, G, and B colors, and borders each of them with gate lines, data lines, And a black matrix covering the thin film transistor and the like and a common electrode covering the thin matrix.

In addition, the driving circuits 146 and 148 are connected to the liquid crystal panel 140 along at least one edge of the flexible circuit board 144 to be flipped to the side of the support main 110 or to the back of the cover bottom 150 during the modularization process. The driving circuits 146 and 148 are gate driving circuits 146 for scanning and transmitting the on / off signals of the thin film transistors to a plurality of gate lines, and a data driving circuit for transmitting image signals for each frame to a plurality of data lines. And separated by 148 and connected to two adjacent edges of the liquid crystal panel 140, respectively.

Therefore, when the thin film transistor selected for each gate line is turned on by the on / off signal voltage of the gate driver circuit 146 which is scanned and transmitted, the signal voltage of the data driver circuit 148 is transferred to the corresponding pixel electrode through the data line. As a result, the arrangement direction of the liquid crystal molecules is changed by the vertical electric field between the pixel electrode and the common electrode, thereby indicating a difference in transmittance.

In addition, the backlight assembly 120 is provided on the rear surface of the liquid crystal panel 140 to supply light such that the difference in transmittance is expressed to the outside, which is a white or silver reflective sheet 122 covering the inner surface of the cover bottom 150. And a fluorescent lamp 124 arranged along an inner longitudinal direction of at least one edge 112 of the support main 110 corresponding to an edge portion thereof, and a reflective sheet to point at the same plane position as the fluorescent lamp 124. Light guide plate 126 seated on 122 and a plurality of optical sheets 128 interposed thereon.

Therefore, the fluorescent lamp 124 faces at least one side of the light guide plate 126, and together with these, the light emitted from the fluorescent lamp 124 is concentrated on the side of the light guide plate 126 corresponding to the fluorescent lamp 124. A lamp housing 130 covering the upper and lower sides of the fluorescent lamp 124 with the inner direction toward at least one side of the 126 opened is interposed along the at least one edge of the support main 110 together with the fluorescent lamp 124. do. That is, the lamp housing 130 surrounds three directions of up and down along the longitudinal direction of the lamp housing 130 to guide the fluorescent lamp 124 therein, and for this purpose, the upper and lower ends are parallel to each other at least one side of the light guide plate 126. The shape of the cross section perpendicular to the longitudinal direction may indicate an approximately C shape. And the material of the lamp housing 130 may be made of a sheet of the same synthetic resin as the reflective sheet 122.

As a result, the light emitted from the fluorescent lamp 124 is concentrated on the side of the light guide plate 126 by the lamp housing 130, and is refracted toward the liquid crystal panel 140. While passing through the optical sheet 128 is processed to a high quality of uniform brightness is irradiated to the liquid crystal panel 140.

In this case, the liquid crystal display module according to the present invention is provided with at least one fixing groove 170 along the upper end of at least one side of the light guide plate 126 facing the fluorescent lamp 124, the upper end of the lamp housing 130 It is characterized in that the fixing groove 170 is inserted into such a bar, referring to Figure 4 showing an enlarged portion A in the circle of the drawing as a preferred example the fixing groove 170 is at least one side of the light guide plate 126 It may have a slit form along the upper longitudinal direction, in which case the upper end of the lamp housing 130 is fitted into the fixing groove 170 of the light guide plate 126 as a whole. The lower end of the lamp housing 130 may be interposed between the light guide plate 126 and the reflective sheet 122.

At this time, the upper and lower widths (a) of the fixing groove 170 may be about 1mm, and the left and right depths (b) may be appropriately selected within a larger range.

Therefore, the upper and lower ends at which the restoring force of the lamp housing 130 made of sheet material is exerted are tightly fixed. In particular, the upper end of the lamp housing 130 is fixed to the fixing groove 170 of the side surface of the light guide plate 126 so that the gap is fixed. Eliminate the possibility of appearance and keep the shape.

Meanwhile, in the liquid crystal display module according to the present invention, the reflective sheet 122 and the lamp housing 130 may be integrally formed, and an exploded perspective view thereof is shown in FIG. For the same reference numerals, the same reference numerals will be omitted.

In this case, as shown, the lamp housing 130 is integrally formed with the reflective sheet 122. Specifically, at least one edge end of the reflective sheet 122 corresponding to the fluorescent lamp 124 is formed outside the fluorescent lamp 124. It is configured to be bent up and inward in two stages.

In this case, at least one fixing groove 170 is preferably formed along the upper end of at least one side surface of the light guide plate 126 facing the fluorescent lamp 124, preferably in a slit shape along the longitudinal direction, and the lamp housing ( The upper end of the 130 is fitted into this fixing groove 170 is fixed. As a result, the upper end of the lamp housing 130 is widened, which greatly reduces the possibility of gaps.

That is, FIG. 6 is a cross-sectional view of a portion of the LCD display module according to the present invention. For convenience, the cross-section of the fluorescent lamp 124 and the lamp housing 130 of FIG. Since it is almost similar to the case described in 4, it is representatively described.

As shown therein, the reflective sheet 122 interposed on the cover bottom 150 and the lamp housing 130 formed integrally therewith and covering the upper and lower sides of the fluorescent lamp 124 are shown, and the inside of the lamp housing 130 is shown. The fluorescent lamp 124 interposed therebetween and a light guide plate 126 seated on the reflective sheet 122 so that one side thereof faces each other, and a plurality of optical sheets 128 covering the light guide plate 126 are shown.

And the upper end of the lamp housing 130 is fixed to the fixing groove 170 formed along the top of one side of the light guide plate 126 facing the fluorescent lamp 124, the lower end of the lamp housing 130 is a reflective sheet ( 122), and although not shown in the drawing, in the case of FIG. 4, the lower end of the lamp housing 130 is interposed between the light guide plate 126 and the reflective sheet 122. It can be seen that the upper and lower ends of are tightly fixed.

The lamp housing according to the present invention as described above can be easily manufactured by forming the desired shape of the lamp housing by forming the incision groove of a depth smaller than the thickness from the outer surface and then bending it on the basis of course can preserve the bending state for a long time. At the same time, the inner surface toward the fluorescent lamp becomes smooth, and light can be focused on the side of the light guide plate with uniform brightness. Therefore, unlike the slit hole of the dotted line cutting the entire lamp housing as in the general case there is an advantage that can prevent the stain due to uneven brightness at the bottom of the screen.

In addition, since the inner surface of the lamp housing according to the present invention defines a separate space disconnected from the outside, there is an advantage of preventing contamination of the fluorescent lamp and the liquid crystal panel due to the infiltration of foreign matter.

Claims (9)

A light guide plate having one or more fixing grooves biased to at least one side top; A fluorescent lamp arranged along the at least one side length direction; A lamp housing having a lower end facing the at least one side such that an upper end is fitted into the fixing groove and the fluorescent lamp bears the fluorescent lamp in its inner longitudinal direction; A plurality of optical sheets covering the light guide plate Backlight assembly for a liquid crystal display device comprising a. The method of claim 1, The fixing groove is a backlight assembly for a liquid crystal display device having a slit shape formed along the longitudinal direction of the at least one side. The method of claim 1, The lower end of the lamp housing is in close contact with the back of the light guide plate. The method of claim 1, The backlight assembly for a liquid crystal display device further comprising a reflective sheet interposed on the back of the light guide plate. The method of claim 4, wherein And the reflective sheet is an integrated body extending from the lower end of the lamp housing. A liquid crystal display module having a backlight assembly according to any one of claims 1 and 2, comprising: A liquid crystal panel seated on the optical sheet; A support main frame that surrounds the backlight assembly and the liquid crystal panel; A cover bottom covering the bottom of the light guide plate; Top cover that borders the front edge of the liquid crystal panel Liquid crystal display module comprising a. The method of claim 6, And a lower portion of the lamp housing is inserted between the light guide plate and the cover bottom. The method of claim 6, And a reflective sheet interposed between the light guide plate and the cover bottom. The method of claim 8, The reflective sheet is an integrated liquid crystal display device module extending from the lower end of the lamp housing.

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