KR102593454B1 - Display - Google Patents

Abstract

The present invention relates to a display device, and in the display device according to the present invention, light leakage can be prevented when a curved surface is formed on the display device by having grooves arranged in the active area of the substrate so that the thickness of the active area is thinner than the non-active area, and the substrate Since the thickness of the inactive area is thicker than the active area, the rigidity of the inactive area becomes stronger, preventing the substrate from being damaged by the driving driver.

Description

display {DISPLAY}

The present invention relates to a display device, and more particularly to a display device that can prevent light leakage and substrate damage.

Video display devices, which display various information on a screen, are a core technology of the information and communication era and are developing into thinner, lighter, more portable, and higher performance. Accordingly, flat panel display devices that can reduce the weight and volume, which are disadvantages of cathode ray tubes (CRTs), are receiving attention.

Flat panel displays generally display images on a flat screen, but recently, curved display devices with a constant radius of curvature have been proposed to further satisfy various functionalities.

However, when thick glass substrates are used as the upper and lower substrates for a curved display device, there is a problem that the thick glass substrate does not bend to the desired curvature, and if it is forcibly bent, the glass substrate is damaged. In addition, the upper and lower substrates of thick glass substrates that are bonded with a cementing agent in between have stress concentrated near the cementing agent. At this time, torsional stress is generated in opposite directions to the upper and lower substrates, and due to this stress, the phase retardation of the substrate, which is proportional to the thickness of the upper and lower substrates, changes significantly, resulting in a very strong level of light leakage. There is a problem.

To solve this problem, using a thin glass substrate increases the ductility of the glass substrate, making it advantageous to implement a curved display device. However, when the rigidity of the glass substrate becomes weak and a driving driver is attached to the glass substrate, the curved glass substrate cannot withstand the stress of the driving driver, causing the glass substrate to break.

The present invention is intended to solve the above problems, and the present invention provides a display device that can prevent light leakage and substrate damage.

In order to achieve the above object, in the display device according to the present invention, a groove is disposed in the active area so that the thickness of the active area of the substrate is thinner than the non-active area, thereby preventing light leakage when forming a curved surface in the display device, and reducing the ratio of the substrate. Since the thickness of the active area is thicker than that of the active area, the rigidity of the non-active area becomes stronger, preventing the substrate from being damaged by the driving driver.

In the display device according to the present invention, the thickness of the active area of each of the upper and lower substrates is formed to be thinner than the thickness of the non-active area. Accordingly, the display device according to the present invention has increased ductility in the active area, making it easier to form a curved surface of 500R or less, and the phase delay of the substrate, which is proportional to the thickness of the upper and lower substrates, is minimized compared to the prior art, thereby reducing light leakage. .

Additionally, in the display device according to the present invention, the thickness of the inactive area of each of the upper and lower substrates is thicker than the active area. Accordingly, in the display device according to the present invention, the rigidity of the inactive area can withstand the stress generated at the contact surface between the driving drivers, thereby preventing damage to the upper and lower substrates.

1 is a plan view showing a display device according to the present invention.
FIG. 2 is a cross-sectional view of the display device taken along line “I-I'” in FIG. 1 .
FIG. 3 is a cross-sectional view showing another embodiment of the display device shown in FIG. 2.
FIGS. 4A and 4B are cross-sectional views showing other embodiments of the upper groove and lower groove shown in FIG. 1.
FIGS. 5A to 5D are cross-sectional views for explaining a method of manufacturing a curved display device using the upper and lower substrates shown in FIG. 1 .
FIG. 6 is a cross-sectional view showing a liquid crystal display device using the upper and lower substrates shown in FIG. 1 .

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

FIG. 1 is a plan view showing a display device according to the present invention, and FIG. 2 is a cross-sectional view showing the display device shown in FIG. 1 .

The display device shown in FIGS. 1 and 2 includes an upper substrate 10 and a lower substrate 20 facing each other with an adhesive 30 interposed therebetween.

Each of the upper and lower substrates 10 and 20 includes an active area (AA) and a non-active area (NA) surrounding the active area (AA).

The active area (AA) is an internal area surrounded by the adhesive 30 and displays an image through unit pixels arranged in a matrix form. A unit pixel is composed of red (R), green (G), and blue (B) sub-pixels, or red (R), green (G), blue (B), and white (W) sub-pixels.

The non-active area (NA) is an area where a signal pad extended from the signal lines of the active area (AA) and a driving driver 40 connected to the signal pad to supply a driving signal to the signal pad are disposed. The driving driver 40 consists of at least one drive IC and is mounted on a circuit film such as TCP (Tape Carrier Package), COF (Chip On Film), FPC (Flexible Print Circuit), and TAB (Tape Automatic Bonding) on the display panel. ) method, or may be mounted on the non-active area (NA) of the lower substrate 20 using a COG (Chip On Glass) method. In particular, the driving driver 40 is disposed on the upper surface of the non-active area (NA) of the lower substrate 20 as shown in FIG. 2, or on the non-active area (NA) of the lower substrate 20 as shown in FIG. 3. It is placed on the lower surface of (NA).

As shown in FIG. 2 , when the driving driver 40 is disposed on the upper surface of the lower substrate 20, the upper substrate 10 is positioned so that the driving driver 40 of the lower substrate 20 is exposed. The area is formed smaller than (20).

And, as shown in FIG. 3, when the driving driver 40 is disposed on the lower surface of the lower substrate 20, the upper substrate 10 has the same area as the lower substrate 20 so as to overlap the driving driver 40. It faces the lower substrate 20. Accordingly, since the non-active area (NA) of the lower substrate 20 can be shielded from light using the outer black matrix of the upper substrate 10, a separate light blocking cover is not required, thereby reducing costs.

This upper substrate 10 is formed to have an upper groove 10a in the active area of at least one of the upper and lower surfaces, as shown in FIGS. 2, 3, 4A, and 4B, and the lower substrate 20 is formed to have a lower groove 20a in the active area AA of at least one of the upper and lower surfaces, as shown in FIGS. 2, 3, 4A, and 4B.

For example, the upper substrate 10 shown in FIGS. 2 and 3 has an upper groove 10a formed on its upper surface, and the lower substrate 20 has a lower groove 20a formed on its lower surface.

The upper substrate 10 shown in FIG. 4A has an upper groove 10a formed on its upper surface, and the lower substrate 20 also has a lower groove 20a formed on its upper surface. In this case, the contact area between the upper surface of the lower substrate 20 and the adhesive 30 increases due to the lower groove 20a, thereby improving the adhesion between the lower substrate 20 and the adhesive 30.

In addition, the upper substrate 10 shown in FIG. 4B has upper grooves 10a formed on its upper and lower surfaces, and the lower substrate 20 also has lower grooves 20a formed on its upper and lower surfaces. In this case, not only does the upper groove 10a increase the contact area between the lower surface of the upper substrate 10 and the cementing agent, but also the lower groove 20a increases the contact area between the upper surface of the lower substrate 20 and the cementing agent 30. ) increases the contact area, thereby improving the adhesion between each of the upper and lower substrates 10 and 20 and the adhesive 30.

In this way, each of the upper substrate 10 with the upper groove 10a and the lower substrate 20 with the lower groove 20a is formed to a first thickness in the active area AA and in the non-active area NA. It is formed to a second thickness that is thicker than the first thickness. For example, the second thickness of each of the upper and lower substrates 10 and 20 in the non-active area (NA) is 100% greater than the first thickness of each of the upper and lower substrates 10 and 20 in the active area (AA). It is formed as thick as ~200㎛.

The first thickness is formed as the minimum thickness capable of supporting a plurality of thin film arrays formed on the upper and lower substrates 10 and 20. For example, the first thickness is formed to be 50㎛ to 100㎛. If the first thickness is less than 50㎛, the plurality of thin film arrays formed on the upper and lower substrates 10 and 20 cannot be supported and the upper and lower substrates 10 and 20 are damaged. If the first thickness exceeds 100㎛, the upper and lower substrates 10 and 20 applied to the curved display device are not bent to the desired curvature, and if they are forcibly bent, the upper and lower substrates 10 and 20 are damaged.

The second thickness is formed as the minimum thickness that can withstand stress generated at the adhesive surface between the drive driver 40 and the lower substrate 20 disposed in the non-active area (NA). For example, the second thickness is formed to be 200 to 300 μm. If the second thickness is less than 200㎛, the stress generated at the adhesive surface between the driving driver 40 and the lower substrate 20 cannot be withstood, and the lower substrate 20 is damaged. When the second thickness exceeds 300㎛, the step between the active area (AA) and the non-active area (NA) increases, causing stress at the boundary between the active area (AA) and the non-active area (NA) to increase, causing the upper and lower substrates (10) ,20) is damaged.

As such, in the display device according to the present invention, the active area AA of each of the upper and lower substrates 10 and 20 is formed to be thinner than the non-active area NA. Accordingly, the display device according to the present invention becomes easier to form a curved surface, and the phase delay of the substrate proportional to the thickness of the upper and lower substrates 10 and 20 is minimized compared to the conventional one, thereby reducing the light leakage phenomenon that occurs when forming a curved display device. It decreases. Additionally, in the display device according to the present invention, the thickness of the non-active area (NA) of each of the upper and lower substrates 10 and 20 is thicker than the active area (AA). Accordingly, in the display device according to the present invention, the rigidity of the non-active area (NA) can withstand the stress generated at the contact surface with the driving driver 40, thereby preventing the upper and lower substrates 10 and 20 from being damaged. You can.

FIGS. 5A to 5D are cross-sectional views for explaining a method of manufacturing a curved display device using the upper and lower substrates shown in FIG. 1 .

First, as shown in FIG. 5A, upper and lower substrates 10 and 20 each having flat upper and lower surfaces are prepared. A plurality of thin film arrays are formed on each of the prepared upper and lower substrates 10 and 20, and then the upper and lower substrates 10 and 20 are bonded using a cementing agent 30, as shown in FIG. 5B. Then, as shown in FIG. 5C, the upper groove 10a and the lower groove 20a are formed by etching a portion of the active area (AA) excluding the non-active area (NA) of the upper and lower substrates 10 and 20, respectively. This is formed. At this time, by bonding the upper and lower substrates 10 and 20 and then etching them, the thin film array formed on each of the upper and lower substrates 10 and 20 can be prevented from being damaged by the etchant and/or etching gas. Then, as shown in FIG. 5D, the upper and lower substrates 10 and 20 are processed to have a certain curvature, thereby completing the curved display panel.

Meanwhile, in the present invention, as shown in FIG. 2, the upper groove 10a and the lower groove 20a are formed one by one on each substrate 10 and 20. However, in addition, each substrate 10 and 20 ) may be formed in multiple numbers. Additionally, when multiple upper grooves 10a and lower grooves 20a are formed, the upper grooves 10a and lower grooves 20a may have uniform depths or may be formed differently depending on their positions.

FIG. 6 is a cross-sectional view showing a liquid crystal display device to which the upper and lower substrates shown in FIG. 1 are applied.

The liquid crystal display device shown in FIG. 6 includes a color filter array 140 and a thin film transistor array 130 facing each other with a liquid crystal layer (not shown) interposed therebetween. Here, the liquid crystal layer is disposed in the active area AA provided by the adhesive 156 between the upper and lower substrates 111 and 101.

The thin film transistor array 130 includes a lower substrate 101 having a lower groove 101a, a thin film transistor 120 formed on the lower substrate 101, a pixel electrode 122, and a common electrode 132. Equipped with

The lower substrate 101 has a lower groove 101a disposed in the active area AA. Due to the lower groove 101a, the lower substrate 101 is formed to have a first thickness in the active area AA and a second thickness thicker than the first thickness in the non-active area NA.

Additionally, the depth of the lower groove 101a is formed to be deeper than or equal to the thickness of the lower polarizer 154. By embedding an optical film such as the lower polarizer 154 in the lower groove 101a, it is possible to prevent the occurrence of a step in the lower substrate 101 at the boundary between the active area AA and the non-active area NA.

The thin film transistor 120 supplies a data signal from a data line to the pixel electrode 122 in response to a gate signal from the gate line. For this purpose, the thin film transistor 120 includes a gate electrode 106, a channel region 114C of the semiconductor layer 114 that overlaps the gate electrode 106 and the gate insulating film 112, and an interlayer insulating film 116. ) and has source and drain electrodes 108 and 110 formed on the semiconductor layer 114 and in contact with the semiconductor layer 114. Here, the source electrode 108 is connected to the source region 114S of the semiconductor layer through the source contact hole 124S, and the drain electrode 110 is connected to the drain region 114D of the semiconductor layer through the drain contact hole 124D. It is connected to.

The common electrode 132 is connected to a common line that supplies a common voltage. In the horizontal electric field type liquid crystal display device, the common electrode 132 is formed parallel to the pixel electrode 122 and alternately with the pixel electrode 122. In the vertical electric field type liquid crystal display device, the common electrode 132 is disposed on the upper substrate 111, and in the fringe electric field type liquid crystal display device, the common electrode 132 has a plurality of slits on the first protective film 118. is formed

The pixel electrode 122 is formed on the second protective film 128 and connected to the drain electrode 110 of the thin film transistor. When a video signal is supplied through the thin film transistor 120, the pixel electrode 122 forms an electric field with the common electrode 132 supplied with a common voltage. Accordingly, the liquid crystal molecules of the liquid crystal layer arranged between the color filter array 140 and the thin film transistor array 130 rotate due to dielectric anisotropy. In addition, the light transmittance passing through the transmission area varies depending on the degree of rotation of the liquid crystal molecules, thereby implementing grayscale.

The color filter array 140 includes an upper substrate 111 having an upper groove 111a, a black matrix 142, a color filter 144, and a planarization layer 146 stacked on the upper substrate 111. .

The upper substrate 111 has an upper groove 111a disposed in the active area AA. Due to the upper groove 111a, the upper substrate 111 is formed to have a first thickness in the active area AA and a second thickness thicker than the first thickness in the non-active area NA.

Additionally, the depth of the upper groove 111a is formed to be deeper than or equal to the thickness of the upper polarizer 152. By embedding an optical film such as the upper polarizer 152 in the upper groove 111a, it is possible to prevent the occurrence of a step in the upper substrate 111 at the boundary between the active area (AA) and the non-active area (NA), thereby creating a borderless ( Boardless implementation becomes possible.

Red, green, and blue color filters 144 are formed on the upper substrate 111 of the active area provided by the black matrix 142 to implement the corresponding colors.

The black matrix 142 is formed on the light blocking area between each sub-pixel, and serves to distinguish each sub-pixel area and prevent light interference and light leakage between adjacent sub-pixel areas. In addition, the black matrix 142 is formed to overlap the boundary area of the non-active area (NA) and the active area (AA), so that the upper and lower substrates 111 and 101 are formed at the boundary between the active area (AA) and the non-active area (NA). Prevents each step from being recognized by the user

The overcoat layer 146 is formed of a transparent organic insulating material such as acrylic resin on the color filter 144 and the black matrix 142. The overcoat layer 146 compensates for the level difference between the color filter 144 and the black matrix 142. Additionally, the overcoat layer 146 serves as a white color filter in the white sub-pixel area where the white color filter 144 is not formed.

As such, in the liquid crystal display device according to the present invention, the active area (AA) of each of the upper and lower substrates 111 and 101 is formed to be thinner than the non-active area (NA). Accordingly, the liquid crystal display device according to the present invention becomes easier to form a curved surface, and the phase delay of the substrate proportional to the thickness of the upper and lower substrates 111 and 101 is minimized compared to the prior art, thereby reducing the light leakage phenomenon that occurs when forming a curved display device. do. In addition, in the liquid crystal display device according to the present invention, the thickness of the non-active area (NA) of each of the upper and lower substrates 111 and 101 is thicker than the active area (AA). Accordingly, in the liquid crystal display device according to the present invention, the rigidity of the non-active area (NA) can withstand the stress generated at the contact surface with the driving driver 160, thereby preventing the upper and lower substrates 111 and 101 from being damaged. there is.

The above description is merely an exemplary description of the present invention, and various modifications may be made by those skilled in the art without departing from the technical spirit of the present invention. Accordingly, the embodiments disclosed in the specification of the present invention do not limit the present invention. The scope of the present invention should be interpreted in accordance with the scope of the patent claims below, and all technologies within the equivalent scope thereof should be interpreted as being included in the scope of the present invention.

10, 111: upper substrate 10a, 111a: upper groove
20, 101: lower substrate 20a, 101a: lower groove
30,156: Cementing agent 40, 160: Drive driver
120: thin film transistor 122: pixel electrode
132: common electrode 142: black matrix
144: Color filter

Claims (9)

an upper and lower substrate each having an active area and an inactive area and facing each other;
at least one groove disposed in the active area so that the thickness of the active area of at least one of the upper substrate and the lower substrate is thinner than the thickness of the non-active area;
an optical film embedded in the at least one groove;
Provided with a cementing agent disposed between the lower surface of the upper substrate and the upper surface of the lower substrate,
The at least one groove is provided on at least one of the lower surface of the upper substrate and the upper surface of the lower substrate, and a step is provided between the inactive area and the active area by the at least one groove,
A display device wherein the adhesive agent is provided to overlap the step. According to claim 1,
The display device further includes a driving driver disposed in a non-active area of the lower substrate that is thicker than the active area. According to claim 2,
The driving driver is attached to the upper surface of the lower substrate,
The upper substrate is arranged to expose the driving driver. According to claim 2,
The driving driver is attached to the lower surface of the lower substrate,
A display device wherein the upper substrate faces the lower substrate so as to overlap the driving driver. According to claim 1,
A display device in which the thickness of the substrate in the non-active area is approximately 100 to 200 μm thicker than the thickness of the substrate in the active area. The method according to any one of claims 1 to 5,
The at least one groove is
an upper groove disposed in the active area of the upper surface of the upper substrate;
The display device further includes a lower groove disposed in the active area of the lower surface of the lower substrate. According to claim 6,
Further comprising a liquid crystal layer disposed in the active area between the upper and lower substrates,
The optical film is
an upper polarizer embedded in the upper groove;
A display device including a lower polarizer embedded in the lower groove. According to claim 7,
The depth of the upper groove is deeper than or equal to the thickness of the upper polarizer,
A display device wherein the depth of the lower groove is deeper than or equal to the thickness of the lower polarizer. According to claim 8,
A display device wherein each of the upper substrate and the lower substrate has a curved shape.

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