KR20140022154A - Liquid crystal display device - Google Patents

Abstract

The present invention provides a liquid crystal display device including a liquid crystal panel, a backlight unit placed at the bottom of the panel and including a light guide plate, a reflective plate, a plurality of optical sheets, and a light source corresponding to one end of the light guide plate, a support main formed into a square frame surrounding the backlight unit, allowing the panel to be placed thereon, and having a groove having a first width and a first depth on a first surface based on a corner part in which the first surface and a second surface touch each other, a light leakage preventing layer composed of black materials formed on the first and second surfaces, and a cover bottom combined with the support main.

Description

[0001] Liquid crystal display device [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display which can prevent light leakage at a mold corner and minimize light loss.

Liquid crystal display devices (LCDs), which are advantageous for moving image display and have a large contrast ratio, are actively used for personal mobile terminals including TVs, monitors, and mobile phones, and are characterized by optical anisotropy of liquid crystals. The principle of image implementation by anisotropy and polarization is shown.

Such a liquid crystal display is an essential component of a liquid crystal panel bonded through a liquid crystal layer between two substrates facing each other, and the transmittance difference is changed by changing the arrangement direction of liquid crystal molecules with an electric field in the liquid crystal panel. Implement

However, since the liquid crystal panel does not have a light emitting element, a separate light source is required to display the difference in transmittance as an image, and for this purpose, a backlight unit having a light source is disposed on the back of the liquid crystal panel.

Herein, any one of a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, and a light emitting diode (LED) may be used as a light source of the backlight unit. use.

In recent years, LEDs have a small size, low power consumption, high reliability, and are widely used as display light sources.

1 is a cross-sectional view of a part of a liquid crystal display device using a general LED as a light source.

As shown in the figure, a typical liquid crystal display device includes a liquid crystal panel 10, a backlight unit 20, a support main 30, a cover bottom 50, and a top cover 40.

In this case, the liquid crystal panel 10 is a part that plays a key role in image expression and is composed of first and second substrates 12 and 14 bonded to each other with a liquid crystal layer interposed therebetween. Polarizing plates for controlling the polarization direction of light are provided on the outer surfaces of the substrates 12 and 14, respectively.

Further, a backlight unit 20 is provided behind the liquid crystal panel 10.

The backlight unit 20 includes an LED assembly 29 arranged along the longitudinal direction of at least one side edge of the support main body 30, a white or silver reflective plate 25 seated on the cover bottom 50, A light guide plate 23 that is seated on the light guide plate 25, and a plurality of optical sheets 21 interposed therebetween.

At this time, the LED assembly 29 is configured on one side of the light guide plate 23, and the plurality of LEDs 29a emitting white light and the LED PCB (printed circuit board: 29b, hereinafter, PCB) on which the LEDs 29a are mounted are referred to as PCBs. ).

The liquid crystal panel 10 and the backlight unit 20 are covered with a top cover 40 covering the upper edge of the liquid crystal panel 10 in a state where the edge is surrounded by the support main 30 having a rectangular frame shape, And the cover bottoms 50 are integrally joined to each other through the support main body 30.

In this case, the top cover 40 may be omitted in the case of a borderless model to maximize the narrow bezel implementation.

As a part of such a liquid crystal display, the corresponding portion will be described in more detail with reference to FIG. 2, which is an enlarged cross-sectional view of region A of FIG.

As shown, the LED 29a is arranged along one side of the light guide plate 23 of the liquid crystal display, and the LED 29a is mounted on the PCB 29b to form the LED assembly 29.

The LED assembly 29 is fixed in a position such as by bonding, so that the light emitted from the plurality of LEDs (29a) to face the light incident surface of the light guide plate 23, for this purpose cover cover 50 is one edge of the upper side Bending to form a side, the LED assembly 29 is mounted on the side of the cover bottom 50 through an adhesive material (not shown) such as a double-sided tape.

This structure is called a side top-view type.

Therefore, the light emitted from each of the LEDs 29a is incident on the light incident surface of the light guide plate 23 and then refracted toward the liquid crystal panel 10 therein, and together with the light reflected by the reflector 25, a plurality of optical rays are emitted. While passing through the sheet 21, it is processed into a more uniform surface light source of high quality and is supplied to the liquid crystal panel 10.

On the other hand, on the other side facing one side of the light guide plate 23 provided with the LED assembly 29 of the liquid crystal display device having such a configuration, the support main 30 faces the other side of the light guide plate 23. Facing.

Therefore, most of the light emitted from the LED assembly path 29 is converted into a sheet resistance through the light guide plate 23 and is incident on the liquid crystal panel 10, but some light passes through the light guide plate 23 as if it passes through the waveguide. Then it comes out through the other end side of the light guide plate (23).

In this case, the light reaching the other end of the light guide plate 23 is incident to the inner surface of the support main 30, the support main 30 is typically made of a white material to reflect some light to the By re-inserting into the other end of the light guide plate 23, the utilization efficiency of light is improved.

However, in the case of the support main 30 made of a white material, some light penetrates into the support main 30 to cause light leakage around the support main 30.

In particular, in the case of a borderless product without a top cover, light leakage is generated through the support main 30 made of the white material around the display area.

 Therefore, in order to prevent light leakage of the support main body 30 made of the white material, the light leakage blocking layer 50 is formed by applying black ink to the inner surface of the support main body 30 made of the white material.

However, the conventional support main 30 faces the side of the liquid crystal panel 10 in a direction perpendicular to the first surface f1 and the first surface f1 on which the bottom surface of the edge portion of the liquid crystal panel 10 is seated. It is made to include a second surface (f2) to have a cross-section of the 'L' shape.

It can be seen that the support main 30 having such a cross-sectional structure has an edge portion where the first surface f1 and the second surface f2 which are perpendicular to each other on the inner surface thereof meet.

In the corner portion existing due to the structural characteristics of the conventional support main 30, the corner portion and the first and second surfaces adjacent to the corner portion in the process of forming the light leakage blocking layer 50 by applying black ink to prevent light leakage Part of (f1, f2) was not smoothly applied to the black ink, as shown in Fig. 3 (photo showing that black ink was applied to the inner surface of the support main body in the conventional liquid crystal display device). The portion which is not coated is generated randomly.

Therefore, in the conventional liquid crystal display device having the support main structure having the above-described structure, the area to which black ink is not applied is randomly generated, and thus the ability to prevent light leakage is reduced. Agglomeration of the ink is generated and is protruded to generate a lift when bonding with other components, causing a problem of lowering the durability of the product.

The present invention is to solve the above problems, it is possible to suppress the occurrence of uncoated area when the black ink is applied to the inner surface of the support main to prevent the light emitted through the light guide plate to cause light leakage through the support main. It is an object of the present invention to provide a liquid crystal display device.

In order to achieve the object described above, another liquid crystal display device according to an embodiment of the present invention, the liquid crystal panel; A backlight unit positioned below the liquid crystal panel and including a reflector, a light guide plate, a plurality of optical sheets, and a light source corresponding to one end of the light guide plate; The first width and the first width of the rectangular unit forming the rectangular frame surrounding the edge of the backlight unit, and seats the liquid crystal panel, and the second surface perpendicular to the first surface on which the liquid crystal panel forming the inner surface meets; A support main, wherein a groove having a first depth is formed in the first surface; A light leakage prevention layer made of a black material formed on the first and second surfaces of the support main; The cover bottom is assembled with the support main.

In this case, the light leakage preventing layer is formed to fill the groove, the portion corresponding to the groove is characterized in having a thicker thickness than the portion formed on the first and second surfaces except the groove.

In addition, the first width is 0.2 to 0.3mm, the first thickness is characterized in that 0.1 to 0.2mm.

In addition, the groove is characterized in that the cross-sectional shape of the square, semi-ellipse, the trapezoidal shape that becomes wider from the bottom to the upper portion, the light leakage prevention layer is any one of black ink, paint, paint or printing method or spray method It is characterized by formed by.

The light source may be any one of an LED assembly including an LED and an LED PCB on which the LED is mounted, a cold cathode fluorescent lamp (CCFL), and an external electrode fluorescent lamp. to be.

And a top cover surrounding the outer surface of the support main and overlapping the edge of the liquid crystal display and fastened to the cover bottom.

As described above, the liquid crystal display according to the exemplary embodiment of the present invention has an edge where the second surface perpendicular to the first surface meets the first surface on which the bottom surface of the liquid crystal panel is seated on the inner surface of the support main. By including this as a reference, the groove has a measure shape on the first surface for a predetermined width, so that the black ink is applied to the corner portion more than other areas, and the corner portion is included in the groove, By allowing the black ink to be filled, there is an effect of fundamentally suppressing the black ink uncoated area generated at the corners.

Furthermore, since the ink coated in the form of grooves in the corner portion is collected, the projections can also be suppressed by the ink agglomeration generated in the vicinity of the ink uncoated area so that the support main and the liquid crystal panel seated thereon can be suppressed. There is an effect to improve the fastening safety and durability of the final product.

1 is a sectional view of a liquid crystal display device using a general LED as a light source.
FIG. 2 is an enlarged cross-sectional view of region A of FIG. 1. FIG.
Figure 3 is a photograph showing that the black ink is applied to the inner surface of the support main in the conventional liquid crystal display device
4 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.
5 is a cross-sectional view of a side end provided with a light source of a liquid crystal display according to an exemplary embodiment of the present invention.
6 is a cross-sectional view of the other end without a light source of the liquid crystal display according to the embodiment of the present invention.
7A to 7C are cross-sectional views of the support main of the liquid crystal display according to the exemplary embodiment of the present invention.
7A and 7B are cross-sectional views of one end of a support main provided in a liquid crystal display according to still another modification of an embodiment of the present invention.
8 is a photo showing that the black ink is applied to the inner surface of the support main in the liquid crystal display according to the embodiment of the present invention.
9A to 9C are cross-sectional views illustrating a black light leakage prevention layer formed on a cross section of a support main that is one component of a liquid crystal display according to an exemplary embodiment of the present invention shown in FIGS. 7A to 7C, respectively.

Hereinafter, a liquid crystal display according to an embodiment of the present invention will be described in detail with reference to the drawings.

4 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention, FIG. 5 is a cross-sectional view of a side end including a light source of the liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 6 is an exemplary embodiment of the present invention. The cross-sectional view of the other end without a light source of the liquid crystal display according to.

As shown in the drawing, the liquid crystal display device 100 according to the embodiment of the present invention includes a cover bottom for modularizing the liquid crystal panel 110 and the backlight unit 120 and the liquid crystal panel 110 and the backlight unit 120. 140 and a support main 200 made of a black mold.

In this case, a top cover (not shown) which surrounds the outer surface of the support main 200 and overlaps the upper surface edge of the liquid crystal panel 110 and is fastened to the cover bottom 150 as necessary. have.

On the other hand, when looking at each of these components in more detail, the liquid crystal panel 110 is a part that plays a key role to represent the image, the first substrate bonded to each other with a liquid crystal layer (not shown) in between 112 and a second substrate 114.

In this case, although not shown in the drawings under the premise of an active matrix method, a plurality of gate wires (not shown) and data wires (not shown) may be provided on an inner surface of the first substrate 112, which is commonly referred to as a lower substrate or an array substrate. A plurality of pixel regions (not shown) are defined to cross each other, and each pixel region (not shown) is a thin film transistor (not shown) that is a switching element near an intersection point of the gate line (not shown) and the data line (not shown). Each pixel region (not shown) is connected to a drain electrode (not shown) of the thin film transistor (not shown) and a pixel electrode (not shown) is formed.

In this case, in addition to the pixel electrode (not shown), the common electrode (not shown) is spaced apart from the pixel electrode (not shown) on the same layer in each pixel area (not shown) according to the driving mode of the liquid crystal display device 100. The pixel electrode may be formed to overlap the pixel electrode (not shown) and the insulating layer (not shown).

When the common electrode (not shown) is configured on the first substrate 112, a common wiring (not shown) may be further provided in parallel with the gate line (not shown), and the common electrode (not shown) may be provided. ) Is electrically connected to the common wiring (not shown).

In addition, an inner surface of the second substrate 114 called an upper substrate or a color filter substrate may be a color filter of red (R), green (G), or blue (B) color, for example, corresponding to each pixel region (not shown). A color filter layer (not shown) including a pattern (not shown) and each of the color filter patterns (not shown), and the gate wiring (not shown), data wiring (not shown), and the thin film transistor (not shown), etc. A black matrix (not shown) is provided which covers the non-display element of.

In addition, a transparent common electrode (not shown) may be formed on the second substrate 114 to selectively overlap the color filter layer (not shown). The common electrode (not shown) configured on the second substrate 114 is omitted when the common electrode (not shown) is provided on the first substrate 112 and the common electrode (not shown) on the first substrate 112. It is formed only when c) is not formed.

In addition, polarizing plates (not shown) for selectively transmitting only light polarized in a specific direction are attached to outer surfaces of the first and second substrates 112 and 114, respectively.

In the liquid crystal panel 110 having such a configuration, printing is performed along at least one edge thereof through a connecting member 116 such as a flexible printed circuit board (FPCB) or a tape carrier package (TCP). The circuit board 117 is connected, and in the process of modularizing it, the circuit board 117 is properly flipped to the side or the back of the support main 130.

In the liquid crystal panel 110 having the above configuration, when a thin film transistor (not shown) selected for each gate wiring (not shown) is turned on by an on / off signal of a gate driving circuit (not shown), the data is turned on. The signal voltage of the driving circuit (not shown) is transmitted to each pixel electrode (not shown) through the data line (not shown), and thus liquid crystal is generated by an electric field between the pixel electrode (not shown) and the common electrode (not shown). The arrangement direction of the molecules is changed to show the transmittance difference.

In addition, the liquid crystal display device 100 according to the embodiment of the present invention is provided with a backlight unit 120 for supplying light from its rear surface such that the difference in transmittance of the liquid crystal panel 110 is expressed to the outside.

The backlight unit 120 includes a white or silver reflecting plate 125, a light guide plate 123 seated on the reflecting plate 125, and a light source disposed corresponding to one side of the light guide plate 123 or both sides facing each other. The LED assembly 129 and the light guide plate 123 are configured to include a plurality of optical sheets 121 interposed below the liquid crystal panel 110.

The LED assembly 129 is positioned on one side of the light guide plate 123 or on opposite sides of the light guide plate 123 so as to face the side surface of the light guide plate 123, respectively. In this case, in the drawing, the LED assembly 129 is shown as being formed only on one side of the light guide plate 123 as an example.

Meanwhile, in the exemplary embodiment of the present invention, the backlight unit 120 is provided with an LED assembly 129 as a light source as an example. However, a cold cathode fluorescent lamp (Cold) may be used as a light source instead of the LED assembly 200. Cathode Fluorescent Lamp (CCFL), External Electrode Fluorescent Lamp (External Electrode Fluorescent Lamp).

When the light source is configured with a cold cathode fluorescent lamp (CCFL) or an external electrofluorescent lamp, a lamp housing (not shown) for reflecting light from the lamp (not shown) may be used. Corresponding to one end of the light guide plate 123 has an opening (not shown) and is further provided to surround the lamp.

On the other hand, as shown, when the LED assembly 129 is provided as a light source of the backlight unit 120, the LED assembly 129 is on one side of the light guide plate 123 to face the light incident surface of the light guide plate 123. The LED assembly 129 includes a plurality of LEDs 129a and LED PCBs 129b on which the LEDs 129a are mounted at regular intervals.

The plurality of LEDs 129a emit light having colors of red (R), green (G), and blue (B) toward the front of the light guide plate 123, and the plurality of RGB LEDs 129a ) Can be turned on at once to realize white light by color mixing.

On the other hand, by using the LED 129a configured with an LED chip (not shown) that emits all the colors of RGB, the white light may be implemented in each LED 129a, or includes a chip (not shown) that emits white color. LED 129a which emits completely white light may be used.

In addition, a plurality of LEDs 129a emitting RGB light may be bundled and mounted in a cluster, and the plurality of LEDs 129a mounted on the PCB 129b may be mounted on the LED PCB 129b. It is also possible to arrange them side by side in a row or in a plurality of rows.

Meanwhile, the light guide plate 123 evenly spreads the light incident from the LED 129a to a wide area of the light guide plate 123 while traveling the inside of the light guide plate 123 by a plurality of total reflections to provide a surface light source to the liquid crystal panel 110. to provide.

The light guide plate 123 may include a pattern of a specific pattern on the back surface to supply a uniform surface light source.

Here, the pattern may be formed in various shapes such as an elliptical pattern, a polygon pattern, a hologram pattern, and the like in order to guide light incident into the light guide plate 123. The pattern is formed on the lower surface of the light guide plate 123 by a printing method or an injection method.

In addition, the reflector plate 125 is positioned on the rear surface of the light guide plate 123 to improve the brightness of the light by reflecting the light passing through the rear surface of the light guide plate 123 toward the liquid crystal panel 110.

The plurality of optical sheets 121 on the light guide plate 123 include a diffusion sheet and at least one light collecting sheet, and diffuse or condense the light passing through the light guide plate 123 to the liquid crystal panel 110. Ensure that a uniform surface light source is incident.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the support main 200 and the cover bottom 150.

In addition, the cover bottom 150 on which the liquid crystal panel 110 and the backlight unit 120 are mounted, and which is the basis for assembling the entire apparatus of the liquid crystal display module, has a rectangular plate-shaped horizontal plane 150A and four edges thereof. Is composed of a vertical height bent side 150b.

In addition, the support main 200 surrounds the edges of the liquid crystal panel 110 and the backlight unit 120 in a rectangular frame shape formed by dividing the positions of the liquid crystal panel 110 and the backlight unit 120 inward. The cover bottom 150 is assembled and fastened.

The support main 200 provides an area where the position of the LED assembly 129 is fixed by a method such as adhesion through one edge portion, and is emitted from the plurality of LEDs 129a of the LED assembly 129 through the edge portion thereof. Light serves to face the light guide plate 123 incident surface.

At this time, in the liquid crystal display device 100 according to an embodiment of the present invention, the most characteristic is the structure of the support main 200.

The support main 200 is characterized in that the injection molded with a white material molded.

Since the support main 200 is made of a white material, the absorption of the light emitted from the backlight unit 120 is basically not generated. Thus, the support main 200 has an effect of improving light efficiency compared to forming the entire support main 200 as a black material. Have

Meanwhile, the most distinctive feature of the support main 200 made of the white material is located perpendicular to the first surface s1 on the first surface s1 on which the bottom surface of the edge portion of the liquid crystal panel 110 is seated. A groove-shaped groove hm having a width of about 0.2 mm to 0.3 mm and a depth of about 0.1 mm to 0.2 mm is formed along the edge portion that meets the second surface s2 facing the side surface of the liquid crystal panel 110. It is characterized by being provided.

The groove hm has a cross sectional shape of FIGS. 7A to 7C (showing a cross sectional shape of the support main of the liquid crystal display according to the exemplary embodiment of the present invention). As shown in the drawing), it may be any one of a rectangular, semi-elliptic, trapezoidal (shape wider from the bottom of the groove (hm) toward the top), the planar shape of the support main It is characterized by forming a rectangular frame in a flat shape. At this time, the cross-sectional shape of the groove (hm) is shown as a drawing only for the rectangular (see Fig. 7a), semi-elliptic (see Fig. 7b) and trapezoidal (see Fig. 7c) as an example, in addition to these to form a polygon or semi-circle It will be apparent that the present invention may be modified in various other forms.

In this case, the width of the groove (hm) is defined as the distance between the surface of the first surface (s1) based on the portion forming the uppermost portion of the groove (hm), that is, the groove (hm), the groove (hm) The depth of is the longitudinal length or height when the groove hm is rectangular or trapezoidal, and is the deepest part from the surface of the first surface s1 in the case of a semi-ellipse, that is, the portion corresponding to the center of the groove hm. Depth.

4, 5, and 6, in the support main 200 made of a white material, a groove hm having the shape as described above is formed on the first surface s1 on which the liquid crystal panel 110 is seated. When the black ink is applied to the inner surface of the support main 200, the black portion of the liquid state before drying is filled in the groove hm, and thus, the edge portion where the first surface and the second surface meet as in the prior art. And the area where the ink is not applied at least in part in the vicinity thereof is generated.

Referring to FIG. 8 (photo showing black ink applied to the inner side of the support main in the liquid crystal display according to the exemplary embodiment of the present invention), a groove (hm in FIG. 6) is formed in the support main (200 in FIG. 6). By forming the edge portion where the first surface (s1 in FIG. 6) and the second surface (s2 in FIG. 6) is included in the groove (hm of FIG. 6), the black ink uncoated region generated near the corner portion is It can be seen that it does not occur.

Meanwhile, referring to FIGS. 4, 5, and 6, an edge where the first surface s1 and the second surface s2 meet by forming a groove hm in the first surface s1 of the support main 200. Since more ink is applied to the part, the black ink is finally dried to form the light leakage preventing layer 255. Thus, the portion where the groove hm is formed has a relatively thicker thickness than other areas, so that the edge is more stable. Light leakage from the part can be prevented.

In addition, when the black ink is applied, the generation of the uncoated area near the corner part is suppressed, whereby the ink agglomeration phenomenon generated in the vicinity thereof can be naturally suppressed.

Accordingly, since the surface of the light leakage prevention layer 255 made of the black ink has a flat surface without protrusion due to the ink agglomeration, the liquid crystal panel 110 is stably contacted when the liquid crystal panel 110 is seated, thereby improving the fastening force and further improving the durability of the product. It has an effect to make.

9A to 9C are cross-sectional views illustrating a light leakage prevention layer formed of a black material on the inner surface of the support main, which is one component of the liquid crystal display according to the exemplary embodiment of the present invention illustrated in FIGS. 7A to 7C, respectively.

As shown, grooves hm having various cross-sectional shapes in the form of squares (see FIG. 9A), semi-ellipses (see FIG. 9B) and trapezoids (see FIG. 9C) are provided so that the other regions for each of these grooves hm are provided. It can be seen that the light leakage preventing layer 255 having a thicker thickness is formed.

On the other hand, although the light leakage prevention layer 255 provided on the inner surface of the support main 220 is mentioned to be formed by applying black ink, in addition to the black ink, a paint or paint having a black color may also be used.

In addition, the printing method or the spray method may be used for the application of any of these black-colored inks, paints and paints.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

100: liquid crystal display
110: liquid crystal panel
112: first substrate
114: second substrate
119a and 119b:
121: optical film
123: light guide plate
125: reflector
150: Burbottum
200: Support Main
255: light leakage prevention layer
hm: home
s1: first side
s2: second side

Claims (7)

A liquid crystal panel;
A backlight unit positioned below the liquid crystal panel and including a reflector, a light guide plate, a plurality of optical sheets, and a light source corresponding to one end of the light guide plate;
The first width and the first width of the rectangular unit forming the rectangular frame surrounding the edge of the backlight unit, and seats the liquid crystal panel, and the second surface perpendicular to the first surface on which the liquid crystal panel forming the inner surface meets; A support main, wherein a groove having a first depth is formed in the first surface;
A light leakage prevention layer made of a black material formed on the first and second surfaces of the support main;
Cover bottom assembled with the support main
And the liquid crystal display device.
The method of claim 1,
Wherein the light leakage preventing layer is formed to fill the groove, and a portion corresponding to the groove has a thickness thicker than a portion formed on the first and second surfaces except for the groove.
The method of claim 1,
The first width is 0.2 to 0.3mm,
The first thickness is a liquid crystal display device of 0.1 to 0.2mm.
The method of claim 1,
And the groove has a quadrangular, semi-ellipse, and trapezoidal shape that is widened from the bottom to the top.
The method of claim 1,
The light leakage preventing layer is any one of black ink, paint, paint is formed by a printing method or a spray method.
The method of claim 1,
The light source includes:
LED assembly comprising an LED and the LED PCB mounted with the LED, a cold cathode fluorescent lamp (CFL), characterized in that any one of an external electrode fluorescent lamp (External Electrode Fluorescent Lamp).
The method of claim 1,
And a top cover surrounding an outer surface of the support main and overlapping the edge of the liquid crystal display device and fastened to the cover bottom.

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