KR102390480B1 - Display device - Google Patents

Abstract

The present invention is provided with a bent film having an upper film coupled to a liquid crystal panel on one side and a bent region bonded to the lower portion of the upper film, and a COF film positioned on the rear surface of the cover bottom while being bent, and the COF film and the cover bottom are fixed fixing tape; It provides a display device comprising a.

Description

display device

The present invention relates to a display device, and more particularly, to a display device capable of implementing a narrow bezel.

In the recent information society, the importance of a display device or a display device as a visual information delivery medium is further emphasized. .

Display is a cathode ray tube (CRT) that emits light by itself, electro luminescence (EL), light emitting diode (LED), vacuum fluorescent display (VFD), field emission It can be divided into a light-emitting type such as a field emission display (FED) and a plasma display panel (PDP), and a non-emission type such as a liquid crystal display (LCD) that does not emit light itself.

Among these various displays, the liquid crystal display is a device that expresses an image by using the optical anisotropy of liquid crystal. It has excellent visibility compared to conventional CRTs, has lower average power consumption compared to CRTs of the same screen size, and also has less heat dissipation. It is popular as a display.

In such a liquid crystal display, an image can be realized by placing a light source under the liquid crystal and controlling the arrangement of the liquid crystal by applying an electric field to the liquid crystal, thereby controlling the transmittance of light generated from the light source. Liquid crystal displays are applied to various electronic devices such as smartphones and tablet PCs. In particular, the liquid crystal display device includes a liquid crystal panel disposed under a cover glass, a backlight unit disposed under the liquid crystal panel, and a cover bottom for accommodating or supporting the liquid crystal panel or the backlight unit. .

However, as the trend these days is toward a slim bezel and an ultra-thin display, the demand for thin and light display devices is increasing.

Recently, the display has gone beyond the slim bezel to implement a narrow bezel that reduces the bezel width as thin as possible.

An object of the present invention is to provide a display device capable of implementing a narrow bezel.

In order to solve the above problems, the present invention includes an upper film, one side of which is coupled to a liquid crystal panel, and a bent film bonded to the lower portion of the upper film and having a bent region, and a COF film positioned on the back surface of the cover bottom while bending; , fixing tape for fixing the COF film and the bottom of the cover; It provides a display device comprising a.

In addition, it provides a display device that is disposed on the side and lower surface of the cover bottom, further comprising a set frame for pressing the outer surface of the bent film of the COF film.

According to the display device of the present invention, a narrow bezel can be realized by reducing the protrusion amount while suppressing the tension through the COF film having the upper film and the bending film, and the protrusion radius can be reduced by pressing the side of the bending film by the set frame. In addition, since the deformation force of the COF film is reduced by reducing the size, it is possible to prevent light leakage due to the lifting of the backlight unit.

1 is a side cross-sectional view of a display device having a COF film of a first embodiment.
FIG. 2 shows the fracture pattern due to tension of the COF film of FIG. 1 .
3 is a side cross-sectional view of a display device having a COF film of a second embodiment.
4 is an exploded view of the COF film of FIG. 3 .
FIG. 5 is a view showing a bonding process of an upper film and a bent film in the COF film of FIG. 4 .
6 is a view showing a change in tension acting on a COF film.
FIG. 7 is a view showing a change in the amount of protrusion of a COF film in the display device of FIG. 3 .

Hereinafter, the embodiments will be clearly revealed through the accompanying drawings and description of the embodiments. In the description of an embodiment, each layer (film), region, pattern or structure is “on” or “under” the substrate, each layer (film), region, pad or pattern. In the case of being described as being formed in, "on" and "under/under" include both "directly" or "indirectly" formed through another layer. do. In addition, the criteria for the upper / upper or lower / lower of each layer will be described with reference to the drawings.

In the drawings, sizes are exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not fully reflect the actual size. Also, like reference numerals denote like elements throughout the description of the drawings. Hereinafter, an embodiment will be described with reference to the accompanying drawings.

1 is a side cross-sectional view of a display device having a COF film of an embodiment, and FIG. 2 shows a breakage form due to tension of the COF film of FIG. 1 .

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

A protective film (not shown) may be provided on the cover glass 110 . In addition, the cover glass 110 may include a touch panel (not shown). In such a touch panel, a pressure-sensitive type that detects a position by coordinates when pressure is applied by tightly installing sensor strings that respond to pressure applied to the surface, and a touch panel after charging an electric charge on the surface of the cover glass 110 and installing sensors around it It can be applied as an electrostatic method that detects the extent of the loss of electric charge and identifies where the contact was made.

The liquid crystal panel 130 includes a color filter substrate 131 in which pixels are arranged in a matrix form to output an image, and a color filter substrate 131 that faces each other and is bonded to maintain a uniform cell gap, an array substrate 133 and a color filter substrate 131 . and a liquid layer (not shown) formed with a cell gap between the array substrate 133 and the array substrate 133 .

The color filter substrate 131 is a color filter composed of a plurality of sub-color filters that implement colors of red, green, and blue (RGB), and a black that distinguishes between the sub-color filters and blocks light passing through the liquid crystal layer. It may consist of a matrix, and an overcoat layer formed on the color filter and the black matrix.

The array substrate 133 has gate lines and data lines that are arranged vertically and horizontally to define a pixel region, and a thin film transistor (TFT), which is a switching element, is formed at the intersection of the gate line and the data line. . The thin film transistor includes a gate electrode connected to a gate line, a source electrode connected to a data line, and a drain electrode connected to a pixel electrode.

In the liquid crystal panel 130 to which the color filter substrate 131 and the array substrate 133 are bonded, a common electrode and a pixel electrode are formed to apply an electric field to the liquid crystal layer, and a voltage is applied to the pixel electrode while the voltage is applied to the common electrode. It is possible to control the voltage of the data signal. Then, the liquid crystal of the liquid crystal layer rotates 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 text or images. In this case, in order to control the voltage of the data signal applied to the pixel electrode for each pixel, a switching device such as a thin film transistor is provided in each pixel.

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

And between the cover glass 110 and the liquid crystal panel 130, an OCR film (not shown) for increasing luminance may be provided. In addition, the lower edge of the liquid crystal panel 130 may be supported by a mold or the guide panel 180 , and the backlight unit 140 is accommodated 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, and an LED for driving the LED 160 . It may include a fixing tape 175 for fixing the FPCB 170 , the LED 160 and the LED FPCB 170 , and a reflecting 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 a plastic material such as PMMA or PC.

A plurality of optical sheets 145 for irradiating the liquid crystal panel 130 by improving the efficiency of light emitted from the light guide plate 150 are provided on the upper surface of the light guide plate 150 .

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 blocking tape 141 . The light blocking tape 141 may have a lower 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 together with the LED FPCB 170 may accompany the function of guiding the bonding position of the optical sheet 145 while fixing the optical sheet 145 . In addition, the light blocking tape 141 attaches the liquid crystal panel 130 and the LED FPCB 170 , and is disposed adjacent to one end of the lower polarizing plate 121 provided under the liquid crystal panel 130 . Accordingly, it is possible to prevent a step difference 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 a portion of the light source 160 and the light guide plate 150 through the double-sided tape 175 . In addition, the double-sided tape 175 for attaching the LED FPCB 170 to the light guide plate 150 may be made of a black color. Then, the light emitted from the light source 160 can be reflected more uniformly by the diffusion sheet extending in the direction of the light incident part, and at the same time, light leakage can be prevented through the black double-sided tape 175 . In addition, the black-colored double-sided tape 175 may partially absorb light in the light incident region, thereby reducing the occurrence of hot spots around the light incident portion.

A reflector (not shown) is positioned between the cover bottom 200 and the rear surface of the light guide plate 150 . The reflector reflects the light emitted from the light source 160 and the light reflected from the light guide plate 150 in the direction of the liquid crystal panel 130 . The light emitted from the light source 160 is incident on the side of the light guide plate 150 made of a transparent material, and the reflective plate disposed on the rear surface of the light guide plate 150 transmits light transmitted through the rear surface of the light guide plate 150 to the optical surface of the upper surface of the light guide plate 150 . By reflecting in the direction of the sheet 145, the loss of light is reduced and the uniformity of luminance is improved.

The backlight unit 140 having the above-described configuration is accommodated in the cover bottom 200 . The backlight unit 140 is not limited to the above-described structure, and any structure of the backlight unit 140 may be applied to the display apparatus 100 according to the present invention.

The cover bottom 200 accommodates the backlight unit 140 and the guide panel 180 therein and may support the liquid crystal panel 130 described above. For example, the cover bottom 200 may have a structure consisting of only a bottom portion and a side portion in order to minimize and slim the bezel area. That is, the cover bottom may include a bottom portion having a square plate shape and a side portion shape protruding upward at a predetermined height from one side of the bottom portion. Of course, the above-described cover bottom 200 is merely exemplary, and even the cover bottom 200 having various shapes may be applied to the display apparatus 100 according to the present invention.

Meanwhile, a driver IC for driving the liquid crystal panel 130 is mounted inside the display device 100 , and the driver IC may be connected to a circuit board to operate.

In general, a driving chip (not shown) inside the display device 100 is of a COG (Chip On Glass) type connected to a flexible circuit board (film) on one side of the liquid crystal panel 130 , that is, on the upper surface of the glass. The mounting method was mainly used.

However, since the COG mounting method of the driving chip has limitations such as the inability to reduce the space where the driving chip is located for slimming the bezel area and realizing the narrow bezel, in this embodiment, the driving chip is a flexible circuit to implement the narrow bezel. A COF (Chip On Film) method that 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 constant length and thickness. One end of the COF film 300 may be coupled to one side of the liquid crystal panel 130 and attached to the back surface 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 with strong tension, even if bending is performed, as shown in FIG. 1 , a protrusion length (L) that still occupies a certain space inevitably occurs, so the amount of bending, that is, the protrusion length (L) needs to be reduced.

In addition, as shown in FIG. 2 , as a restoring force is generated in the bending section due to strong tension of the COF film 300 , the connection section between the liquid crystal panel 130 and the backlight unit 140 or the backlight unit 140 is widened or There may be problems with breakage.

Accordingly, the present invention may further include other embodiments as follows to solve the above-described problems.

3 is a side cross-sectional view of a display device having a COF film of a second embodiment, FIG. 4 is a developed view of the COF film of FIG. 3, and FIG. 5 is the bonding process of the upper film and the bending film in the COF film of FIG. 6 is a view showing a change in tension acting on the COF film, and FIG. 7 is a view showing a change in the amount of protrusion of the COF film in the display device of FIG. 3 .

3 to 7 , in the display device 10 of the second embodiment, the structure of the COF film 300a is different from that of the first embodiment. That is, the COF film 300a does not have a structure that protrudes toward the outside of the backlight unit 140 like the COF film 300 of the first embodiment described above, but protrudes toward the inside of the backlight unit 140, that is, it is viewed from the outside. It may have a recessed shape when

As shown in FIGS. 4 and 5 to have such a structure, for example, the COF film 300a is formed in which the upper film 300a-1 and the bending films 300a-2 and 300a-3 are combined. can be

Referring to FIG. 3 , the upper film 300a-1 may have one side coupled to the liquid crystal panel 130 and the other side exposed to the outside of the backlight unit 140 . The bent films 300a-2 and 300a-3 may have a length such that one side is bonded to the lower portion of the upper film 300a-1 and the other side is bent to be positioned on the rear surface of the cover bottom 200 . That is, the bent films 300a - 2 and 300a - 3 may include a bent area 300a - 2 to be bent and a lower area 300a - 3 attached to the rear surface of the cover bottom 200 after bending.

As shown in FIG. 4 , the upper film 300a-1 and the bent films 300a-2 and 300a-3 are formed by cutting one COF film 300a, and the upper film 300a-1 and the bent film In (300a-2, 300a-3), portions located on the same surface may be bonded to each other. As shown in FIG. 6 , the cut portion of the upper film 300a-1 is experimentally selected as an area "B" with the greatest tension in consideration of the effect of the tension F in the outward direction when the COF film 300 is bent. , can be chosen computationally.

In addition, in the upper film 300a-1 and the bent films 300a-2 and 300a-3 to be cut, the bent region 300a-2 and the lower region 300a-3 may be integrally formed. Of course, the bending films 300a-2 and 300a-3 may be composed of two members so that the lower region 300a-3 is separated from the bending region 300a-2 as needed.

Here, an anisotropic conductive film 500 (ACF) may be disposed between the upper film 300a-1 and the bent films 300a-2 and 300a-3.

The anisotropic conductive film 500 (ACF, Antisotropic Conductive Film) refers to a double-sided adhesive film in which an adhesive cured by heat and fine conductive balls are mixed therein. When a high-temperature pressure is applied to the anisotropic conductive film 500, the conductive balls in the portion in contact with the pads of the circuit pattern are destroyed, and the destroyed conductive balls conduct electricity between the pads, and the remaining adhesive is filled and cured on the uneven surface other than the pad portion. to make them adhere to each other

Accordingly, as shown in FIG. 5 , the upper film 300a-1 and the bent films 300a-2 and 300a-3 are pressed and bonded by the anisotropic conductive film 500 . At this time, as described above, the upper film 300a-1 and the bent films 300a-2 and 300a-3 have portions positioned on the same surface bonded to each other, so as shown in FIG. 6 , the COF film of the first embodiment The COF film 300a of the second embodiment may act in the opposite direction, that is, in the inner direction, by reversely using the tension F acting in the protrusion direction at 300 .

In addition, the second embodiment is disposed on the side and lower surfaces of the cover bottom 200 to further suppress the tension by pressing the outer surfaces of the bent films 300a-2 and 300a-3 of the COF film 300a. It further includes a set frame 400 . For example, the set frame 400 may include a horizontal member 410 and a vertical member 420 .

The horizontal member 410 may be positioned on the lower surface of the cover bottom 200 , and the vertical member 420 may be disposed on one side of the horizontal member 410 to be adjacent to the side surface of the cover bottom 200 .

At this time, the vertical member 420 is the bending film (300a-2, 300a-3) to suppress the tension directed to the outside while pressing the bending region (300a-2) of the bending film (300a-2, 300a-3) It may have a protruding surface convexly protruding toward the . Accordingly, the COF film 300a may maintain a recessed shape by suppressing the tension to protrude to the outside.

Accordingly, as shown in FIG. 7 , the display device 10 of the present embodiment reduces the bending amount further than the protrusion length L for the COF film 300a of the display device 1 of the first embodiment (by L1). ) can have one protruding length L2.

That is, the protrusion length L2 is the length of the lower region 300a-3 of the bending films 300a-2 and 300a-3 from the joint between the upper film 300a-1 and the bending films 300a-2 and 300a-3. Not only can it be reduced to become the distance to the interface, but also the protrusion radius is further reduced than in the first embodiment described above.

As described above, according to the display device of the present invention, the narrow bezel reduces the amount of protrusion while suppressing the tension through the COF film 300a having the upper film 300a-1 and the bending films 300a-2 and 300a-3. can be implemented, and the side (bending area) of the bending films 300a-2 and 300a-3 is pressed by the set frame 400 to reduce the protrusion radius as well, so that the deformation force of the COF film is reduced, so the backlight unit 140 It is possible to prevent light leakage caused by the lifting of

The display device according to the above-described embodiment of the present invention may be applied to various electronic equipment such as a TV, a smartphone, and a tablet PC.

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by a person skilled in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

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: light blocking 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
300, 300a: COF film 300a-1: upper film
300a-2: bending area (bending film) 300a-3: lower area (bending film)
400: set frame 410: horizontal member
420: vertical member 500: anisotropic conductive film

Claims (7)

liquid crystal panel;
a backlight unit disposed under the liquid crystal panel;
a cover bottom supporting the backlight unit and the liquid crystal panel;
a COF film having an upper film, one side of which is coupled to the liquid crystal panel, and a bent film bonded to a lower portion of the upper film and having a bent region, and positioned on a rear surface of the cover bottom while being bent; and
a fixing tape for fixing the COF film and the cover bottom; Including, a display device. The method of claim 1,
The bent film further includes a lower region extending from the bent region and adhered to the rear surface of the cover bottom. 3. The method of claim 2,
The display device further includes an anisotropic conductive film (ACF) disposed between the upper film and the bent film, wherein the upper film and the bent film are bonded by the anisotropic conductive film while being pressed. 4. The method of claim 3,
The upper film and the bent film are made by cutting a single COF film, and the upper film and the bent film have portions positioned on the same surface bonded to each other. 5. The method according to any one of claims 1 to 4,
The display device, which is disposed on the side surface and the lower surface of the cover bottom, further comprising a set frame for pressing the outer surface of the bent film of the COF film. 6. The method of claim 5,
The set frame is
a horizontal member positioned on a lower surface of the cover bottom; and
and a vertical member disposed on one side of the horizontal member and adjacent to a side surface of the cover bottom. 7. The method of claim 6,
The vertical member has a protruding surface convexly protruding toward the bent film, the display device.

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