KR20100072652A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: A liquid crystal display device is provided to prevent light leakage due to an adhesive material between an FPCB and a light guide plate. CONSTITUTION: A support main(130) includes a square frame shape arranged along with one side edge of a light source(129a). The support main includes a protruded jaw toward the inner side of the square frame. A liquid crystal panel(110) is mounted in the protruded jaw. A light shielding tape(200) is attached to the upper part of the protruded jaw by an adhesive material layer(205). The light shielding tape covers a part of an edge of optical sheets(121). A top cover(140) is combined with the support main and a cover bottom(150).

Description

Liquid crystal display device

The present invention relates to a liquid crystal display device, and more particularly to a light shielding tape that can block light leakage.

In line with the recent information age, the display field has also been rapidly developed, and a liquid crystal display device (FPD) is a flat panel display device (FPD) having advantages of thinning, light weight, and low power consumption. LCD, plasma display panel device (PDP), electroluminescence display device (ELD), field emission display device (FED), etc. : It is rapidly replacing CRT.

Among them, LCDs are excellent in moving image display and are most actively used in notebooks, monitors, TVs, etc. due to high contrast ratio. The LCDs are devices that do not have their own light emitting elements. It requires a light source.

As a result, a backlight unit having a lamp is provided on the rear side to irradiate light toward the front of the liquid crystal panel, thereby realizing an image of identifiable luminance.

On the other hand, a cold cathode fluorescent lamp (Cold Cathode Fluoresent Lamp), an external electrode fluorescent lamp (External Electrode Fluoresent Lamp), and a light emitting diode (LED) are used as the light source of the backlight unit.

Among them, LEDs are particularly widely used as display light sources having features such as small size, low power consumption, and high reliability.

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

As illustrated, a general liquid crystal display module includes a liquid crystal panel 10, a backlight unit 20, a support main 30, a cover bottom 50, and a top cover 40.

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.

In addition, polarizers (not shown) are attached to upper and lower surfaces of the liquid crystal panel 10, and a backlight unit 20 is provided behind the liquid crystal panel 10.

In this case, the backlight unit 20 includes an LED assembly 29 arranged along at least one edge length direction of the support main 30, a white or silver reflecting plate 25 mounted on the cover bottom 50, and the like. The light guide plate 23 mounted on the reflective plate 25 and a plurality of optical sheets 21 interposed thereon are included.

The LED assembly 29 is configured on one side of the light guide plate 23, and includes a plurality of LEDs 29a emitting light and a flexible printed circuit board 29B on which the LEDs 29a are mounted.

The liquid crystal panel 10 and the backlight unit 20 have a top cover 40 surrounding the top edge of the liquid crystal panel 10 and a back surface of the backlight unit 20 in a state where the edges are surrounded by the support main 30 having a rectangular frame shape. Cover cover 50 to cover each is coupled in front and rear are integrated through the support main 30 as a medium.

As a part of the liquid crystal display module, 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. 1.

As shown, the LED 29a is arranged along one side of the light guide plate 23 of the general liquid crystal display module, and the LED 29a is mounted on the FPCB 29b.

At this time, only one LED 29a is shown in the drawing, but a plurality of LEDs 29a are mounted on the FPCB 29b at regular intervals, thereby lighting white light at a time.

The LED assembly 29 is fixed in a position such as by bonding, so that the light F emitted from the plurality of LEDs 29a faces the light incidence portion of the light guide plate 23. For this purpose, the light incidence portion of the light guide plate 23 is used. The side is attached and fixed to the lower surface of the FPCB 29b of the LED assembly 29 through an adhesive material 60 such as a double-sided tape.

Accordingly, the light F emitted from the LED 29a is refracted toward the liquid crystal panel 10 after being incident on the light incident part of the light guide plate 23 and is reflected by the reflective sheet 25. While passing through the optical 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, such a liquid crystal display device has a large display area and has a significantly reduced weight and volume, and in recent years, attempts to provide a thin liquid crystal display device by reducing the volume of the backlight unit 20 have been made.

However, the liquid crystal display device exhibits some problems. Particularly, some of the light emitted from the LED 29a generates light leakage through the adhesive material 60 between the FPCB 29b and the light guide plate 23. do.

As a result, the quality of the liquid crystal display, such as a decrease in luminance and color uniformity, is degraded.

The present invention has been made to solve the above problems, and the present invention is intended to prevent light leakage of the liquid crystal display device.

For this reason, the second object is to improve the luminance and color uniformity of the liquid crystal display device.

In addition, a third object of the present invention is to prevent the withdrawal of a plurality of optical sheets.

In order to achieve the object as described above, the present invention is covered covertum; A backlight unit including a light source and a plurality of optical sheets seated on the cover top; A support main having a rectangular frame shape arranged along one edge of the light source and including a protruding jaw toward the inside of the rectangular frame; A liquid crystal panel seated on the protruding jaw of the support main; A light-shielding tape attached to an upper portion of the protruding jaw and formed to cover a portion of edges of the plurality of optical sheets; And a top cover covering an upper edge of the liquid crystal panel and coupled to the support main and the cover bottom, wherein the adhesive material layer of the light shielding tape is formed only at a portion attached to the protruding jaw. to provide.

In this case, the light shielding tape is formed of a base film made of a black PET resin and an adhesive material layer, and the adhesive material layer is formed to cover only a width of about 1/2 from the outer edge of the base film to the inside.

Here, one surface on which the adhesive material layer of the base film made of PET resin is formed may have a white color or silver color, and the light shielding tape has a predetermined width so as to overlap a part of an edge rear surface of the liquid crystal panel.

In addition, the upper surface of the projection jaw includes a step to which the adhesive material layer of the light-shielding tape is attached, the light source is an LED assembly, a cold cathode fluorescent lamp or an external LED assembly consisting of a plurality of LEDs and a plurality of LEDs are mounted One of the electrode fluorescent lamps. The light guide plate may be further included on the reflective plate.

As described above, when the shading tape covers a part of the edge of the optical sheet to prevent light from leaking to a portion outside the screen display area of the liquid crystal panel, the adhesive material layer of the shading tape is attached to the support main according to the present invention. By forming only the area to be made, there is an effect that the light shielding tape and the optical sheet is not directly bonded to prevent the optical sheet from moving by fixing the optical sheet.

As a result, light leakage due to the portion of the adhesive material between the FPCB and the light guide plate can be prevented, thereby improving the luminance and color uniformity of the liquid crystal display.

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

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

As illustrated, the liquid crystal display module includes a liquid crystal panel 110, a backlight unit 120, a support main 130, a cover bottom 150, and a top cover 140.

First, the liquid crystal panel 110 plays a key role in image expression and includes a first substrate 112 and a second substrate 114 bonded to each other with the liquid crystal layer interposed therebetween.

At this time, although not shown in the drawings under the premise of an active matrix method, a plurality of gate lines and data lines are intersected on the inner surface of the first substrate 112, which is commonly referred to as a lower substrate or an array substrate, to define pixels. Thin film transistors (TFTs) are provided at each intersection to correspond one-to-one to the transparent pixel electrodes formed in each pixel.

In addition, the inner surface of the second substrate 114 called the upper substrate or the color filter substrate may correspond to each pixel, for example, a color filter of red (R), green (G), and blue (B) color, and each of them. A black matrix covering the non-display elements such as gate lines, data lines, and thin film transistors is provided. In addition, a transparent common electrode covering them is provided.

A polarizer (not shown) for selectively transmitting only specific light is attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

In addition, the printed circuit board 117 is connected through at least one edge of the liquid crystal panel 110 through a connecting member 116 such as a flexible printed circuit board or a tape carrier package (TCP) to support the modularization process. The side surface of the main 130 or the cover bottom 150 is properly folded to be in close contact.

Accordingly, in the liquid crystal panel 110 having the above-described structure, when the thin film transistor selected for each gate line is turned on by the on / off signal of the gate driver circuit which is scanned and transmitted, the signal voltage of the data driver circuit is applied to the corresponding pixel through the data line. The direction of the liquid crystal molecules is changed by the electric field between the pixel electrode and the common electrode.

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

The backlight unit 120 includes an LED assembly 129, a white or silver reflector 125, a light guide plate 123 seated on the reflector 125, and a plurality of optical sheets 121 interposed thereon. Include.

In addition, the light shielding tape 200 may further include a light blocking tape 200 between the plurality of optical sheets 121 and the liquid crystal panel 110 to prevent light from leaking to portions outside the screen display area of the liquid crystal panel 110.

In this case, the light shielding tape 200 is not directly bonded to the optical sheet 121 positioned at the top of the plurality of optical sheets 121. As a result, warping of the optical sheet 121 may be prevented. We will discuss this in more detail later.

The LED assembly 129 described above is located at one side of the light guide plate 123 so as to face the light incident part of the light guide plate 123, and the LED assembly 129 has a plurality of LEDs 129a and its LEDs 129a constant. And FPCBs 129b mounted spaced apart from each other.

In this case, the plurality of LEDs 129a emits light having red (R), green (G), and blue (B) colors toward the light-receiving portion of the light guide plate 123, respectively, and the plurality of RGB LEDs (129a). ) Can be lit at once to realize white light by color mixing.

In this case, by using the LED 129a configured with an LED chip (not shown) that emits all the colors of RGB, the white light may be realized in each LED 129a, or including a chip emitting white color. The emitting LED 129a may be used.

Meanwhile, a plurality of LEDs 129a emitting RGB light may be bundled and mounted in a cluster, and a plurality of LEDs 129a mounted on the FPCB 129b may be arranged on the FPCB 129b. It is also possible to arrange them side by side or to arrange them side by side in a plurality of columns.

The light guide plate 123 evenly spreads the light incident from the plurality of LEDs 129a to a wide area of the light guide plate 123 while propagating through the light guide plate 123 by a plurality of total reflections to provide a surface light source to the liquid crystal panel 110. do.

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

Here, the pattern may be configured in various ways, such as an elliptical pattern, a polygon pattern, a hologram pattern, and the like to guide the 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.

The reflective plate 125 is positioned on the rear surface of the light guide plate 123, and reflects light passing through the rear surface of the light guide plate 123 toward the liquid crystal panel 110 to improve the brightness of the light.

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 provide a more uniform surface to the liquid crystal panel 110. Allow the light source to enter.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the top cover 140, the support main 130, and the cover bottom 150, and the top cover 140 is formed on the top surface of the liquid crystal panel 110. A rectangular frame having a cross section bent in a shape of “a” so as to cover the side edge, and opens the front surface of the top cover 140 to display an image implemented in the liquid crystal panel 110.

In addition, the cover bottom 150 on which the liquid crystal panel 110 and the backlight unit 120 are seated, and which is the basis for assembling the entire structure of the liquid crystal display device module, has a rectangular plate shape and vertically bends its four edges to a predetermined height. Configure.

In addition, the support main 130 having a rectangular frame shape seated on the cover bottom 150 and covering the edges of the liquid crystal panel 110 and the backlight unit 120 may include the top cover 140 and the cover bottom 150. Combined.

Here, a protruding end 131 of a predetermined shape is formed on the inner surface of the support main 130 so that the light shielding tape 200 is attached to the upper surface of the support main 130 and supports a portion of the rear surface of the liquid crystal panel 110.

In this case, the top cover 140 may also be referred to as a case top or a top case, and the support main 130 may also be referred to as a guide panel, a main support, or a mold frame, and the cover bottom 150 may be referred to as a bottom cover or a lower cover. It is also built.

4A is a perspective view schematically illustrating a structure of a light shielding tape according to an embodiment of the present invention, and FIG. 4B is a bottom perspective view of FIG. 4A.

As shown, the light shielding tape 200 is composed of a base film 203 made of PET resin and an adhesive material layer 205, which is black overall for efficient light shielding.

The overall shape of the light shielding tape 200 is a rectangular frame having first and third edges 200a and 200c corresponding to the printed circuit board 117 of FIG. 3 and the first edge of the liquid crystal panel 110 of FIG. The second edge 200b facing the edge 200a and the fourth edge facing the third edge 200c are formed.

The four edges 200a, 200b, 200c, and 200d of the light blocking tape 200 may cover a width of a portion of the edges of the plurality of optical sheets (121 of FIG. 3) seated on the light guide plate (123 of FIG. 3). It is preferable to comprise so that it may have.

The upper surface of the base film 203 of the light blocking tape 200 protrudes from the inner surface of the support main layer 130 of the support main layer 205 such that the adhesive material layer 205 faces the liquid crystal panel 110 of FIG. 3. It is attached to the upper surface of (131 in FIG. 3), and the light is shielded so that light does not leak to a portion outside the screen display area of the liquid crystal panel (110 in FIG. 3).

At this time, as shown in FIG. 4B, the adhesive material layer 205 of the light shielding tape 200 attached to the protruding end (131 of FIG. 3) of the support main (130 of FIG. 3) is the outer side of the light shielding tape 200. It is formed only along the edges.

That is, the adhesive material layer 205 of the light shielding tape 200 is formed under the base film 203 so as to cover only about 1/2 of the width from the outer edge of the base film 203 to the inside thereof. The inner edge of the 203 is formed to be exposed.

Thus, when the light shielding tape 200 is attached to the protruding end (131 of FIG. 3) of the support main (130 of FIG. 3) through the adhesive material layer 205, a plurality of optical sheets (121 of FIG. 3) are provided. The optical sheet and the light shielding tape 200 positioned at the top of each other are not directly bonded to each other.

As a result, the withdrawal of the optical sheet 121 (see FIG. 3) may be prevented.

In more detail, in the liquid crystal display, high heat is generated by heat generated from an integrated circuit or the like (LED 129a of FIG. 3) used as a light source. This heat is transferred to a plurality of optical sheets (121 of FIG. 3) having a low coefficient of thermal expansion such that the plurality of optical sheets (121 of FIG. 3) are thermally expanded and thermally contracted.

At this time, when the light-shielding tape 200 fixes the edge of the optical sheet located at the top of the plurality of optical sheets (121 of FIG. 3) through the adhesive force of the adhesive material layer 205, the thermal expansion and thermal contraction of the optical sheet It is fixed by the light shielding tape 200, and a warping phenomenon occurs.

This causes a problem of deterioration of the liquid crystal display such as staining on the screen.

Therefore, in the present invention, the light shielding tape 200 covers a part of the edge of the optical sheet (121 of FIG. 3) to shield light from leaking to a portion outside the screen display area of the liquid crystal panel (110 of FIG. By not fixing the optical sheet 121 of FIG. 3 through 200, the movement of the optical sheet 121 of FIG. 3 may be prevented.

Meanwhile, the base film 203 of the light shielding tape 200 is configured to have a black color as a whole, but the lower portion of the base film 203 on which the adhesive material layer 205 is formed is configured to have a white or silver color, so that Some light can be reflected for shading.

Further, in the drawings and the detailed description, the overall shape of the light shielding tape 200 has been described as a rectangular frame shape, but the overall shape of the light shielding tape 200 may be variously modified according to the shape of the liquid crystal panel (110 of FIG. 3).

5 is a schematic cross-sectional view of some cross-section of FIG. 3 modularized.

As illustrated, the reflective plate 125, the light guide plate 123, the LED assembly 129 provided on one side of the light guide plate 123, and a plurality of optical sheets 121 are stacked on the light guide plate 123. It forms a backlight unit.

The LED assembly 129 is fixed in position by bonding or the like so that the light emitted from the plurality of LEDs 129a faces the light entering part of the light guide plate 123. The FPCB 129b of 129 is attached and fixed through an adhesive material 160 such as a double-sided tape.

In addition, the liquid crystal panel 110 having a liquid crystal layer (not shown) interposed therebetween is disposed between the backlight unit and the first and second substrates 112 and 114, and the first and second substrates 112 and 114. On each of the outer surfaces of), a polarizing plate (not shown) for selectively transmitting only specific light is attached.

The backlight unit and the liquid crystal panel 110 are surrounded by edges by the support main 130, and the cover bottom 150 is coupled to the rear surface of the backlight unit and the liquid crystal panel 110, and the top cover 140 covering the upper edge and side surfaces of the liquid crystal panel 110. Is coupled to the support main 130 and cover bottom 150.

At this time, the inner surface of the support main 130 is formed with a protruding end 131 protruding from a certain shape, and the light shielding tape 200 is attached to the upper end of the protruding end 131 and the liquid crystal panel 110 is attached. Supported.

The light blocking tape 200 is formed to cover a portion of the lower surface of the liquid crystal panel 110 and to cover a portion of the edges of the plurality of optical sheets 121 stacked on the light guide plate 123.

On the other hand, the light shielding tape 200 is composed of a base film 203 and an adhesive material layer 205, where the adhesive material layer 205 is about 1/2 inward from the outer edge of the base film 203. It is formed so as to cover only the width.

Therefore, the light shielding tape 200 is attached to the protruding end 131 of the support main 130 through the adhesive material layer 205 and the exposure of the base film 203 on which the adhesive material layer 205 is not formed. The regions are formed to cover the edges of the plurality of optical sheets 121.

Therefore, the optical sheet and the light shielding tape 200 positioned at the top of the plurality of optical sheets 121 are not directly bonded to each other.

Therefore, some lights emitted from the LED 129a are directly emitted to the liquid crystal panel 110 through the light guide plate 123 between the FPCB 129b and the light guide plate 123. It can be seen that the light is reduced by the light leakage is significantly reduced.

In addition, according to the present invention, the adhesive material layer 205 of the light shielding tape 200 is not directly bonded to the optical sheet positioned at the top of the plurality of optical sheets 121 so as not to fix the optical sheet 121. In this case, the backing of the optical sheet 121 may be prevented.

FIG. 6 is a schematic cross-sectional view of a partial cross section of a modular liquid crystal display according to a second exemplary embodiment of the present invention.

In this case, in order to avoid redundant description, the same reference numerals are given to the same parts that play the same role as the description of FIG. 5, and only the characteristic contents to be described above will be described.

As shown, the light shielding tape 200 is formed of a black base film 203 and an adhesive material layer 205, where the adhesive material layer 205 is inward from an outer edge of the base film 203. It is formed so as to cover only about 1/2 the width.

The light shielding tape 200 is attached to the inner surface of the support main 130 through the adhesive material layer 205 on the upper surface of the protruding end 131 protruding from a predetermined shape, and the screen display of the liquid crystal panel 110 is performed. Light is blocked to prevent the light from leaking out of the area.

At this time, the stepped stepped step 135 to which the adhesive material layer 205 of the light blocking tape 200 is attached is formed on the upper surface of the protruding end 131 of the support main 130. That is, the stepped 135 is configured such that a part of the upper surface of the protruding end 131 of the support main 130 forms a step shape in cross section.

Therefore, the exposed area of the base film 203 on which the adhesive material layer 205 of the light shielding tape 200 is not formed covers the edges of the plurality of optical sheets 121. The gap between the optical sheets 121 can be reduced.

As described above, the light shielding tape 200 covers a part of the edge of the optical sheet 121 so that light is not leaked to a portion outside the screen display area of the liquid crystal panel 110. By preventing the optical sheet 121 from being fixed, the movement of the optical sheet 121 may be prevented.

As a result, there is an effect of improving the luminance and color uniformity of the liquid crystal display device.

In this case, the backlight unit (120 of FIG. 3) having the above-described structure is generally called a side light method, and according to the purpose, the LED assembly 129 may be configured along the inner longitudinal direction of both edges of the support main 130 facing each other. Although not shown in a separate drawing, it is also possible to use a direct backlight unit.

In this case, a plurality of LED assemblies 129 may be arranged side by side in a state where the light guide plate 123 is omitted in the above-described structure, and a plurality of optical sheets 121 may be interposed therebetween.

In addition to the LED 129a, a fluorescent lamp such as a cold cathode fluorescent lamp or an external electrode fluorescent lamp may be used.

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.

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

FIG. 2 is an enlarged cross-sectional view of region A of FIG. 1. FIG.

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

Figure 4a is a perspective view schematically showing the structure of a light shielding tape according to an embodiment of the present invention.

4B is a bottom perspective view of FIG. 4A.

FIG. 5 is a schematic cross-sectional view of a partial cross section of FIG. 3 modularized;

FIG. 6 is a schematic cross-sectional view of a portion of a modular liquid crystal display device according to a second embodiment of the present invention; FIG.

Claims (8)

Covertum; A backlight unit including a light source and a plurality of optical sheets seated on the cover top; A support main having a rectangular frame shape arranged along one edge of the light source and including a protruding jaw toward the inside of the rectangular frame; A liquid crystal panel seated on the protruding jaw of the support main; A light-shielding tape attached to an upper portion of the protruding jaw and formed to cover a portion of edges of the plurality of optical sheets; A top cover that covers an upper edge of the liquid crystal panel and is coupled to the support main and the cover bottom And the adhesive material layer of the light shielding tape is formed only at a portion attached to the protruding jaw. The method of claim 1, The light blocking tape includes a base film made of black PET resin and an adhesive material layer. The method of claim 2, And the adhesive material layer is formed to cover only about 1/2 the width of the adhesive material inward from the outer edge of the base film. The method of claim 2, One side of the adhesive material layer of the base film made of the PET resin is formed a liquid crystal display device of the white or silver color. The method of claim 1, And the light blocking tape has a predetermined width so as to overlap a portion of a rear surface of the edge of the liquid crystal panel. The method of claim 1, And an upper surface of the protruding jaw includes a step to which an adhesive material layer of the light blocking tape is attached. The method of claim 1, The light source is a liquid crystal display device selected from a LED assembly, a cold cathode fluorescent lamp or an external electrode fluorescent lamp consisting of a plurality of LEDs and FPCB mounted with a plurality of LEDs. The method of claim 1, And a light guide plate on the reflective plate.

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