KR20190072877A - Display device - Google Patents

Abstract

According to the present invention, provided is a display device comprising: a liquid crystal panel; a backlight unit disposed on a lower part of the liquid crystal panel; a cover bottom supporting the backlight unit and the liquid crystal panel; a COF film having one side coupled to the liquid crystal panel and bent, so as to be adhered to the rear surface of the cover bottom; and a bonding part coated on the rear surface of the COF film and filling an inner space where the COF film is bent, while being in contact with the backlight unit. Therefore, an objective of the present invention is to provide the display device capable of implementing a narrow bezel.

Description

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a display device capable of implementing a narrow bezel.

In recent information society, the importance of display device or display device as a visual information delivery medium is emphasized more and it is necessary to meet requirements such as low power consumption, thinning, light weight, and high image quality in order to take a major position in the future .

The display includes a cathode ray tube (CRT), an electroluminescence (EL), a light emitting diode (LED), a vacuum fluorescent display (VFD) A light emitting type such as a field emission display (FED), a plasma display panel (PDP) or the like, and a non-light emitting type such as a liquid crystal display (LCD)

Of these various displays, the liquid crystal display device is an apparatus that expresses an image using the optical anisotropy of the liquid crystal, and has an excellent visibility as compared with a conventional cathode ray tube, and has an average power consumption as well as a small amount of heat dissipation It is widely regarded as a display.

In such a liquid crystal display device, an image can be realized by controlling a light transmittance of a light source by controlling the arrangement of liquid crystal by applying a electric field to the liquid crystal with a light source disposed under the liquid crystal. Liquid crystal display devices are applied to various electronic devices such as smart phones and tablet PCs. Particularly, in a liquid crystal display device, a liquid crystal panel is disposed under a cover glass, a backlight unit is disposed under the liquid crystal panel, and a cover bottom for receiving or supporting the liquid crystal panel or the backlight unit .

Nowadays, the demand for slim bezel and thin and light display devices are increasing as the trend is toward ultra slim display.

Recently, the display has come to realize a narrow bezel that slides the bezel beyond the slim bezel as thin as possible.

The present invention provides a display device capable of implementing a narrow bezel.

In order to solve the above problems, the present invention provides a bonding unit which is bonded to a liquid crystal panel and is applied to a back surface of a COF film bonded to a back surface of a cover bottom while bending, and filled in an inner space where the COF film is bended while being in contact with the backlight unit And a display device.

In addition, the present invention provides a display device further comprising an engaging groove for improving bonding force with the bonding portion in the cover bottom.

According to the display device of the present invention, the inner bezel can be realized by applying the COF film and the bonding portion. Since the fixing force is further increased by the bonding portion during the COF film bending with strong tension, It is possible to prevent the light leakage phenomenon caused by the light.

In addition, according to the display device of the present invention, it is possible to realize a Narrow inner bezel by applying a COF film, a bonding part and a joining groove, and when the COF film bending having a strong tension is bending, So that the light leakage phenomenon due to lifting of the backlight unit can be prevented.

1 is a side cross-sectional view of a display device having a COF film of an embodiment.
Fig. 2 shows the breakage of the COF film of Fig. 1 due to tension.
3 is a side cross-sectional view of a display device having a COF film according to another embodiment.
FIGS. 4 and 5 are views showing a process of forming a bonding portion on the COF film of FIG.
6 is an experimental result table of the protrusion amount of the COF film including the bonding portion.
7 is a side cross-sectional view of a display device having a COF film according to another embodiment.
8 is a perspective view of the cover bottom region of FIG. 7;

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure may be referred to as being "on" or "under" a substrate, each layer It is to be understood that the terms " on "and " under" include both " directly "or" indirectly " do. In addition, the criteria for the top / bottom or bottom / bottom of each layer are described with reference to the drawings.

In the drawings, dimensions are exaggerated, omitted, or schematically illustrated for convenience and clarity of illustration. Also, the size of each component does not entirely reflect the actual size. The same reference numerals denote the same elements throughout the description of the drawings. Hereinafter, embodiments will be described with reference to the accompanying drawings.

Fig. 1 is a side sectional view of a display device having a COF film of the embodiment, and Fig. 2 shows a mode of breakage due to a tensile force of the COF film of Fig.

1 and 2, a display device 100 according to a first embodiment of the present invention includes a cover glass 110, a liquid crystal panel 130, a backlight unit 140, a cover bottom 200, And a COF film 300.

The cover glass 110 may be provided with a protective film (not shown) on its upper surface. In addition, the cover glass 110 may include a touch panel (not shown). Such a touch panel is a pressure sensitive type in which a sensor string responsive to a pressure applied to a surface is densely arranged to detect a position in coordinates when a pressure is applied, a pressure type sensor for filling a charge on the surface of the cover glass 110, It can be applied electrostatically to detect the extent to which the charge has been lost and to determine where the contact has taken place.

The liquid crystal panel 130 includes a color filter substrate 131 and a color filter substrate 131. The color filter substrate 131 includes pixels arrayed in a matrix form to output images, And a cell gap formed liquid layer (not shown) between the array substrate 133 and the array substrate 133.

The color filter substrate 131 includes a color filter composed of a plurality of sub-color filters implementing colors of red, green, and blue (RGB), and a color filter that separates sub-color filters and blocks light transmitted through the liquid crystal layer A matrix, and an overcoat layer formed over the color filter and the black matrix.

A gate line and a data line are vertically and horizontally arranged on the array substrate 133 to define a pixel region, and a thin film transistor (TFT), which is a switching device, is formed in a crossing region between the gate line and the data line . The thin film transistor includes a gate electrode connected to the gate line, a source electrode connected to the data line, and a drain electrode connected to the pixel electrode.

A common electrode and a pixel electrode are formed on the liquid crystal panel 130 in which the color filter substrate 131 and the array substrate 133 are bonded together to apply an electric field to the liquid crystal layer. It is possible to control the voltage of the data signal. Then, the liquid crystal of the liquid crystal layer is rotated by dielectric anisotropy according to the electric field between the common electrode and the pixel electrode, thereby transmitting or blocking light for each pixel to display characters or images. In this case, in order to control the voltage of the data signal applied to the pixel electrode on a pixel-by-pixel basis, a switching element such as a thin film transistor is individually provided in each pixel.

Polarizing plates 120 and 121 may be attached to the upper and lower outer sides of the color filter substrate 131 and the array substrate 133, respectively. At this time, the lower polarizer 121 polarizes the light passing through the backlight unit 140 toward the array substrate 133, and the upper polarizer 120 polarizes the light transmitted through the liquid crystal panel 130.

An OCR film (not shown) may be provided between the cover glass 110 and the liquid crystal panel 130 to increase brightness. A lower edge of the liquid crystal panel 130 may be supported by a mold or a guide panel 180 and a backlight unit 140 may be housed in the guide panel 180.

The backlight unit 140 includes a light guide plate 150 disposed under the liquid crystal panel 130, an LED 160 as a light source disposed on one side of the light guide plate 150 to generate light, An FPCB 170, a fixing tape 175 for fixing the LED 160 and the LED FPCB 170, and a reflection plate (not shown).

The light guide plate 150 receives light from the light source 160 and guides the light toward the liquid crystal panel 130. The light guide plate 150 may be made of plastic material such as PMMA or PC.

On the upper surface of the light guide plate 150, a plurality of optical sheets 145 are provided to improve the efficiency of light emitted from the light guide plate 150 and irradiate the liquid crystal panel 130.

The optical sheet 145 includes a diffusion sheet and a prism sheet, and a brightness enhancement film such as DBEF and a protective sheet may be added. The optical sheet 145 may be provided between the upper surface of the light guide plate 150 and the rear surface of the liquid crystal panel 130.

The upper side of the LED FPCB 170 may be attached to the upper portion of the guide panel 180 through the light shielding tape 141. The light shielding tape 141 may have a bottom surface attached to the upper surface of the LED FPCB 170, and one end may be positioned on the upper surface of the optical sheet 145. Therefore, the light shielding tape 141 along with the LED FPCB 170 can accompany the function of guiding the joining position of the optical sheet 145 while fixing the optical sheet 145. The light shielding tape 141 adheres the liquid crystal panel 130 and the LED FPCB 170 and is arranged adjacent to one side end of the lower polarizer plate 121 provided below the liquid crystal panel 130. Therefore, it is possible to prevent a step between the liquid crystal panel 130 and the backlight unit 140 from occurring.

The lower side of the LED FPCB 170 may be attached to the light source 160 and a part of the light guide plate 150 through the double-sided tape 175. The double-sided tape 175 for attaching the LED FPCB 170 on the light guide plate 150 may be made of black color. The light emitted from the light source 160 may function to more uniformly reflect the light by the diffusion sheet extending in the direction of the light entrance portion and may prevent the light leakage phenomenon through the double-sided tape 175 of black color And the black colored double-sided tape 175 absorbs a part of the light in the light-incoming area to reduce the occurrence of hot spots around the light-incoming area.

The reflection plate (not shown) is positioned between the cover bottom 200 and the back surface of the light guide plate 150. The reflection plate reflects the light emitted from the light source 160 and the light reflected from the light guide plate 150 toward the liquid crystal panel 130. The light emitted from the light source 160 is incident on a side surface of the light guide plate 150 of transparent material and the reflection plate disposed on the back surface of the light guide plate 150 reflects light transmitted through the back surface of the light guide plate 150, It is reflected in the direction of the sheet 145 to reduce the loss of light and improve the uniformity of brightness.

The backlight unit 140 including the above-described configuration is housed inside the cover bottom 200. [ The backlight unit 140 is not limited to the above-described structure, and any backlight unit 140 of any structure can be applied to the display device 100 according to the present invention.

The cover bottom 200 may house the backlight unit 140 and the guide panel 180 to support the liquid crystal panel 130 described above. For example, the cover bottom 200 may have a structure having only a bottom portion and a side portion for minimizing and slimming the bezel region. That is, the cover bottom may include a bottom portion in the shape of a rectangular plate and a side portion protruding upward from the bottom portion at a predetermined height. Of course, the cover bottom 200 may be applied to the display device 100 according to the present invention.

 A driver IC for driving the liquid crystal panel 130 is mounted in the display device 100 and a driver IC is connected to the circuit board.

In general, a driving chip (not shown) in the display device 100 is mounted on one side of a liquid crystal panel 130, that is, on a glass, and a COG (Chip On Glass) type Mounting method was mainly used.

However, since the COG mounting method of the driving chip has a limit such that the space in which the driving chip is located can not be reduced in order to make the bezel area slimmer and realize the narrow bezel, the driving chip, in the present embodiment, A COF (Chip On Film) method which is directly mounted on a substrate (film) is used.

The COF film 300 may include a driving chip (not shown) and a circuit capable of driving the driving chip, and may have a film shape having a predetermined length and thickness. One end of the COF film 300 is bonded to one side of the liquid crystal panel 130 and can be attached to the backside of the cover bottom 200 by the double-sided tape 210 while being bent.

However, since the COF film 300 is made of a material having a strong tension, the bending amount, that is, the protruding length L is inevitably generated even when bending is performed, .

In addition, a restoring force may be generated in the bending section due to the strong tension of the COF film 300, thereby causing a problem that the connection section of the liquid crystal panel 130 and the backlight unit 140 or the backlight unit 140 is opened or broken .

Therefore, in order to solve the above-described problems, the present invention may further include the following other embodiments.

FIG. 3 is a side sectional view of a display device having a COF film according to another embodiment, and FIGS. 4 and 5 are views showing a process of forming a bonding portion in the COF film of FIG.

3 to 5, the display device 10 of another embodiment may further include a bonding portion 400 in addition to the configuration of the display device 1 of the above-described embodiment.

The bonding portion 400 is filled in the inner space bent at the bottom of the COF film 300, thereby fixing the COF film 300 to the backlight unit 140, thereby suppressing the tension. Accordingly, the COF film 300 including the bonding portion 400 can be firmly fixed together with the backlight unit 140 and the cover bottom 200 after being bent. Accordingly, the present embodiment can further reduce the bending amount of the COF film 300 to further reduce the projecting length L (by L1 in FIG. 3), and furthermore, the lifting effect of the backlight unit 140 .

For example, the bonding part 400 may be implemented by any one of a UV type resin and a natural hardening type (PUR) resin. Here, the resin may be referred to as Glue, Bond, and the like.

The UV type resin may be applied to a lower portion (back surface) of the COF film 300, and cured through ultraviolet rays (UV), followed by bending to form the bonding portion 400. The UV type resin has an advantage that the width to be applied to the COF film 300 can be reduced.

On the other hand, the natural-curing resin may be applied to a lower portion (back surface) of the COF film 300 as shown in FIGS. 4 and 5, and then subjected to a bending operation in a liquid state before curing. 3, when the end of the COF film 300 is pulled to the right as shown by the arrow, the bonding part 400 formed while spreading in the inner space where the resin is bent bends the backlight unit and the COF film 300 They can be brought into close contact with each other. Accordingly, the natural-curing resin can fix the COF film 300 on the back surface of the cover bottom 200 through the double-sided tape 210 while adjusting the bending amount to be minimized.

6 is an experimental result table of the protrusion amount of the COF film including the bonding portion.

As shown in FIG. 6, the protruding amount of the COF film 300 including the bonding portion 400 of the present embodiment was compared. Experimental conditions were that the gap between one edge of the liquid crystal panel 130 and the edge of the backlight unit 140 was 0.4 mm and the bonding unit 400 was a UV type resin and a natural hardening type PUR resin Two types were used.

The UV-type resin was prepared by using two kinds of resins having a material name of 190024 and AA3381 and changing the resin application width of the back surface of the COF film 300 to 0.432 mm and 0.505 mm, Were classified as Case 1 and Case 2. Case 3 and Case 4, in which the protruding amount of the COF film 300 was experimented by using one type of resin having a material name of 3542 and changing the resin application width of the COF film 300 to 0.837 mm and 0.122 mm, Respectively.

6 and 3, in the embodiment of the bonding portion 400, the UV type resin can minimize the application width, but the protrusion length L2 of the COF film 300 is relatively larger (L2) of the bending section can be reduced to 0.361 mm as compared with the application amount of the natural curing lane.

As described above, the display device 10 of the present embodiment can realize a narrow bezel that can further reduce the protruding length L1 by more than the above-mentioned embodiment by applying the COF film 300 and the bonding portion 400, Since the fixing force is further increased by the bonding part 400 when bending the COF film 300 with strong tension, it is possible to prevent light leakage due to lifting of the backlight unit.

7 is a side cross-sectional view of a display device having a COF film according to still another embodiment, and Fig. 8 is a perspective view of the cover bottom region of Fig.

7 and 8, the display device 10a of the present embodiment further improves the bonding force of the bonding portion 400a in the display device 10 of the above-described embodiment, thereby further reducing the projecting length L3 have.

To this end, the cover bottom 200a may further include a coupling groove 250 to improve a coupling force with the bonding portion 400a of the display device 10a of the present embodiment.

The coupling groove 250 may be formed by cutting one side of the cover bottom 200a along the longitudinal direction in which the bonding portion 400a is grained. For example, the coupling groove 250 may have a shape inclined downward from the upper surface of the cover bottom 200a toward the lower portion adjacent to the bonding portion 400a as shown in FIGS.

When the bonding portion 400a is applied, the bonding groove 250 can reduce the application amount of the bonding portion 400a while allowing the resin to flow into the cover bottom 200a. The coupling groove 250 also increases the contact area between the bonding portion 400a and the cover bottom 200a to improve the fixing force so that the bonding portion 400a is firmly fixed to the backlight unit 140. [

Therefore, the display device 10a of the present embodiment can be provided with a protruding length L3 in which the bending amount is reduced more than the protruding lengths L and L2 of the COF film of the display devices 1 and 10 of the above- do.

As described above, the display device of the present invention can realize a narrow bezel that can reduce the protruding length by applying the COF film, the bonding portion, and the coupling groove. When the COF film having strong tension is bending, So that the light leakage phenomenon due to lifting of the backlight unit can be prevented.

The display device according to the embodiment of the present invention can be applied to various electronic devices such as a TV, a smart phone, a tablet PC, and the like.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments can be combined and modified by other persons having ordinary skill in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

1, 10: Display device 110: Cover glass
120, 121: polarizing film 130: liquid crystal panel
131: color filter substrate 133: array substrate
140: Backlight unit 141: Shading tape
145: optical sheet 150: light guide plate
160: LED 170: LED FPCB
175: fixing tape 180: mold (guide panel)
200: cover bottom 210: fixing tape
250: coupling groove 300: COF film
400, 400a: bonding part

Claims (6)

A liquid crystal panel;
A backlight unit disposed below the liquid crystal panel;
A cover bottom supporting the backlight unit and the liquid crystal panel;
A COF film having one side bonded to the liquid crystal panel and bonded to the backside of the cover bottom while being bent; And
And a bonding portion that is applied to the back surface of the COF film and contacts the backlight unit to fill the inner space where the COF film is bent. The method according to claim 1,
Wherein the bonding portion includes one of a UV type resin and a natural curing type resin. 3. The method of claim 2,
Wherein the natural-curing resin is applied to the back surface of the COF film in a liquid state, and then is bent and adhered to the cover bottom before curing. 4. The method according to any one of claims 1 to 3,
Wherein the cover bottom further comprises an engaging groove for enhancing a bonding force with the bonding portion. 5. The method of claim 4,
And the engaging groove is formed by cutting one side of the cover bottom along the longitudinal direction to which the bonding portion is applied. 6. The method of claim 5,
And the engaging groove has a shape inclined downward from an upper surface of the cover bottom toward a lower portion adjacent to the bonding portion.

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