Patent Description:
As a demand for high-resolution and high-visibility displays increases in the fields of automobiles, mobile devices, TVs, and the like, in recent years, display devices having excellent characteristics such as thinness and flexibility have been developed in the field of display technology. In particular, a curved display device for increasing the visibility of a display has been actively developed.

On the other hand, the display device is provided with a display for displaying screen information and a cover glass for protecting the display. In order to manufacture a curved display device, a curved cover glass must be provided therein. The curved cover glass must be processed to have the same curvature as that of the curved display.

In the related art, the curved display device has been manufactured by a method of bonding a light-transmitting adhesive layer to a flexible display and then bonding it to a curved cover glass. In this method, since curved lamination must be performed, there is a problem in that a process difficulty is increased, and a curved lamination process must be redesigned when there is a variation in a curved surface of the display device.

<CIT> discloses a method of forming a curved vehicle display. <CIT> discloses an apparatus for manufacturing a flat panel display. <CIT> discloses a method of manufacturing a curved display device.

Therefore, to obviate those problems, an aspect of the detailed description is to provide a manufacturing method capable of easily bonding a curved display and a curved cover glass during the manufacture of the curved display.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a method of manufacturing a curved display device, as defined in appended claim <NUM>, the method including coupling a flat display, an optical clear adhesive, and a cover glass to manufacture a flat display assembly, applying an adhesive to an edge of the flat display assembly, seating the flat display assembly on a curved jig, sucking the flat display assembly to a surface of the curved jig using a vacuum hole disposed in the curved jig such that the flat display assembly is bent, and coupling a backlight unit to a region to which the adhesive is applied, wherein the coupling of a backlight unit to a region to which the adhesive is applied comprises curing the adhesive while the backlight unit is pressed to the display assembly so as to maintain a bent state of the display assembly.

According to an embodiment, the curved jig may be provided with a plurality of vacuum holes, and the sucking of the flat display assembly to a surface of the curved jig may be performed by depressurizing an inside of the vacuum holes.

According to an embodiment, the seating of the flat display assembly on a curved jig may be performed by a first lift pin coming into contact with a central portion of the flat display assembly and a second lift pin coming into contact with an edge portion of the flat display assembly.

According to an embodiment, each of the first and second lift pins may include a vacuum suction pad that is vacuum-sucked to the display assembly.

According to an embodiment, the seating of the flat display assembly on a curved jig may include seating the flat display assembly on first and second lift pins, moving the first and second lift pins to the curved jig such that the flat display assembly and the curved jig overlap each other, and descending the first and second lift pins to seat the flat display assembly on the curved jig.

According to an embodiment, the descending of the first and second lift pins to seat the flat display assembly on the curved jig may be performed by descending the first and second lift pins until the flat display assembly comes into contact with an uppermost portion of the curved jig, and the sucking of the flat display assembly to a surface of the curved jig may be performed by descending the second lift pin.

According to an embodiment, the sucking of the flat display assembly to a surface of the curved jig may be performed while maintaining a suction force of the vacuum suction pad provided in the second lift pin.

According to an embodiment, the coupling of a backlight unit to a region to which the adhesive is applied may include fixing the display assembly and the backlight unit with a clamp so as to maintain the display assembly in a bent state.

According to an embodiment, the method may further include fixing the display assembly with a clamp to maintain the display assembly in a bent state after sucking the flat display assembly to a surface of the curved jig.

According to an embodiment, the coupling of a flat display, an optical clear adhesive, and a cover glass to manufacture a flat display assembly may be performed by roll lamination.

In accordance with the detailed description, a roll lamination process may be performed when a display and a cover glass are in a flat state, and thereby it is not required to design a lamination process for a curved surface. Further, according to the present disclosure, a curved surface of a curved jig may be changed according to a curvature of a display assembly to be implemented, thereby maximizing the productivity and profitability of a curved display.

Hereinafter, an embodiment disclosed herein will be described in detail with reference to the accompanying drawings, and the same or similar elements are designated with the same numeral references regardless of the numerals in the drawings and their redundant description will be omitted. A suffix "module" and "unit" used for constituent elements disclosed in the following description is merely intended for easy description of the specification, and the suffix itself does not give any special meaning or function. In describing an embodiment disclosed herein, moreover, the detailed description will be omitted when specific description for publicly known technologies to which the invention pertains is judged to obscure the gist of the present disclosure. Furthermore, it should be noted that the accompanying drawings are merely illustrated to easily explain the concept of the invention, and therefore, they should not be construed to limit the technological concept disclosed herein by the accompanying drawings.

Moreover, it will be understood that when an element such as a layer, region or substrate is referred to as being "on" another element, it can be directly on the other element or an intermediate element may also be interposed therebetween.

Prior to describing a manufacturing method according to the present disclosure, a method of bonding a curved cover glass to a display in the related art will be described.

<FIG> is a flowchart showing a method of bonding a curved cover glass to a display in the related art, and <FIG> and <FIG> are conceptual views showing a method of bonding a curved cover glass to a display in the related art.

Referring to the drawings, first, removing a protective film 120a from one surface of an optical clear adhesive (OCA) <NUM> both surfaces of which are covered with protective films 120a and 120b, and pressing a flat display <NUM> against the optical clear adhesive <NUM> (S101 to S104) is carried out.

At this time, pressing between the optical clear adhesive <NUM> and the flat display <NUM> may be performed by a roll lamination method (R), but is not limited thereto.

Then, removing air bubbles formed between the optical clear adhesive <NUM> and the flat display <NUM> (S105) is performed. Here, the removing of the air bubbles may be carried out by atmospheric defoaming (auto clave).

Then, removing the protective film 120b from one surface of the optical clear adhesive <NUM> and attaching the optical clear adhesive <NUM> to a curved cover glass <NUM> is carried out. At this time, the optical clear adhesive <NUM> to which the display <NUM> is attached is bonded to the cover glass <NUM> through roll lamination (R). In this process, the flat display <NUM> is bent.

Then, removing air bubbles formed between the optical clear adhesive <NUM> and the cover glass <NUM> (S110) is carried out. Here, the removing of the air bubbles (S110) may be carried out atmospheric defoaming (auto clave). In the present specification, a state in which the cover glass <NUM>, the optical clear adhesive <NUM>, and the display <NUM> are bonded will be referred to as a display assembly <NUM>.

Subsequent to the completion of the display assembly <NUM>, assembling a back cover to the display assembly is carried out. When the display included in the display assembly is an LCD display, assembling a backlight unit is carried out prior to the assembly of the back cover.

Meanwhile, a separate adhesive may be used to prevent separation between the back cover and the display assembly when assembling the display assembly and the back cover.

The foregoing method in the related art has a problem in that it is difficult to implement a facility for a curved surface because roll lamination must be performed on the curved cover glass. In addition, there are disadvantages in that it is difficult to manufacture the curved cover glass and the price is very high compared to a flat cover glass. The present disclosure provides a manufacturing method for implementing a curved display device using a flat cover glass and a flat display.

Specifically, the present disclosure provides a manufacturing method capable of implementing a curved display while using an existing roll lamination facility for bonding a flat cover glass and a flat display as it is.

<FIG> are conceptual views showing a method of manufacturing a curved display device according to the present disclosure.

Referring to the drawings, first, removing a protective film 220a from one surface of an optical clear adhesive (OCA) <NUM> both surfaces of which are covered with protective films 220a and 220b, and pressing a flat display <NUM> against the optical clear adhesive <NUM> is carried out.

Here, the optical clear adhesive <NUM> may be a silicone-based or acrylic-based optical clear adhesive <NUM>, but is not limited thereto.

In this case, pressing between the optical clear adhesive <NUM> and the flat display <NUM> is performed in a roll lamination method. The bonding process may be performed inside a vacuum chamber. A pressure inside the chamber may be <NUM> to <NUM> Pa.

An inside of the vacuum chamber includes an adhesive chuck or an electro static chuck (ESC) capable of sucking the optical clear adhesive <NUM> and the display <NUM>, and is provided with a robot or transfer device for putting and taking the display <NUM> therein and therefrom. Further, the vacuum chamber is disposed with upper/lower adhesive chucks thereinside, and configured with suction lift pins for transferring the optical clear adhesive <NUM> and the display <NUM>, and separate vacuum suction holes to fix the optical clear adhesive <NUM> and the display <NUM> to the adhesive chucks. In addition, a plurality of optical devices for precisely aligning the optical clear adhesive <NUM> and the display <NUM> may be disposed inside the vacuum chamber.

Meanwhile, immediately after the optical clear adhesive <NUM> and the display <NUM> are put into the vacuum chamber, depressurization inside the vacuum chamber may not be completed. In the present disclosure, an alignment between the optical clear adhesive <NUM> and the display <NUM> and depressurization inside the chamber are simultaneously performed.

Accordingly, an alignment between the optical clear adhesive <NUM> and the display <NUM> may be performed at pressures of <NUM> to <NUM> Pa, and a bonding process between the optical clear adhesive <NUM> and the display <NUM> may be performed in a vacuum atmosphere of <NUM> to <NUM> Pa.

Next, removing air bubbles formed between the optical clear adhesive <NUM> and the flat display <NUM> is carried out. Here, the removing of the air bubbles may be carried out by atmospheric defoaming (auto clave).

In one embodiment, the defoaming condition may be performed at pressures of <NUM> to <NUM>/cm<NUM>, at temperatures of <NUM> to <NUM> for <NUM> to <NUM> minutes.

Next, removing the protective film 220b from one surface of the optical clear adhesive <NUM> and attaching the optical cover glass <NUM> to the flat cover glass <NUM> is performed. At this time, the optical clear adhesive <NUM> to which the display <NUM> is attached is bonded to the cover glass <NUM> through roll lamination (R). This process is performed inside the foregoing vacuum chamber.

An alignment between the optical clear adhesive <NUM> and the cover glass <NUM> is performed at pressures of <NUM> to <NUM> Pa, and a bonding process between the optical clear adhesive <NUM> and the cover glass <NUM> may be performed in a vacuum atmosphere of <NUM> to <NUM> Pa.

Then, since the flat cover glass <NUM> is bent at an outer side of the display <NUM> in the process, an area of the flat cover glass <NUM> must be larger than that of the display <NUM>. When the defoaming step is finished, the display assembly <NUM> is completed.

Hereinafter, a process of assembling a backlight unit and a back cover to the display assembly <NUM> will be described.

Referring to <FIG>, applying an adhesive <NUM> to an edge of the display assembly <NUM> is carried out. Here, the edge denotes an edge of the flat cover glass <NUM> that does not overlap the display <NUM>.

The adhesive <NUM> may be an acrylic-based, silicone-based, or urethane-based adhesive, but is not limited thereto. The adhesive may also be an adhesive in the form of a film. Meanwhile, a curing method of the adhesive may be UV curing, thermal curing, or natural curing. The curing method of the adhesive may vary depending on the type of the adhesive.

Then, applying an external force to bend the display assembly <NUM> is performed. The bending of the display assembly <NUM> will be described in detail later.

Meanwhile, in order to assist a physical force for bending the display assembly <NUM>, a first clamp C1 may be disposed at an edge of the display assembly <NUM>. However, the first clamp C1 is not essentially required.

Then, a part of the backlight unit <NUM> is brought into contact with a position where the adhesive <NUM> is applied, and the adhesive <NUM> is cured. In this case, a second clamp C2 may be provided at an edge of the backlight unit <NUM> such that the display assembly <NUM> and the backlight unit <NUM> are strongly coupled to each other. The adhesive <NUM> is cured while the second clamp C2 is provided.

Then, applying the adhesive <NUM> to the backlight unit <NUM> is carried out. Here, since the adhesive <NUM> is used for the purpose of coupling the backlight unit <NUM> and the back cover <NUM> to each other, a position to which the adhesive <NUM> is applied may vary depending on shapes of the backlight unit <NUM> and the back cover <NUM>. The adhesive <NUM> must be applied to a region where the backlight unit <NUM> and the back cover <NUM> come into contact with each other.

The adhesive <NUM> may be an acrylic-based, silicone-based, or urethane-based adhesive, but is not limited thereto. The adhesive <NUM> may be an adhesive in the form of a film. Meanwhile, a curing method of the adhesive <NUM> may be UV curing, thermal curing, or natural curing. The curing method of the adhesive may vary depending on the type of the adhesive.

Then, coupling the back cover <NUM> thereto is performed. In this case, the back cover <NUM> may be coupled to the backlight unit <NUM> in a state in which the adhesive layer <NUM> is formed in a partial region. The adhesive layer <NUM> formed on a partial region of the back cover <NUM> increases a coupling force between the backlight unit <NUM> and the back cover <NUM>.

Subsequent to coupling the back cover <NUM> to the backlight unit <NUM>, curing the adhesive <NUM> to the backlight unit <NUM> is carried out. At this time, a third clamp may be provided at an edge of the back cover <NUM> such that the back cover <NUM> and the backlight unit <NUM> are strongly coupled to each other. The adhesive <NUM> is cured in a state in which the third clamp is provided.

As described above, in the present disclosure, a curved display is manufactured by physically bending a flat cover glass. For this reason, the present disclosure does not require a curved lamination process. Through this, the present disclosure may allow a curved display to be implemented while using an existing roll lamination facility for bonding a flat cover glass and a flat display as it is.

Hereinafter, a method of assembling the backlight unit and the back cover in a state in which the display assembly is physically bent will be described in more detail.

<FIG> are conceptual views showing a method of assembling a backlight unit and a back cover in a state in which a display assembly is physically bent.

First, referring to <FIG>, the flat display assembly <NUM> is put into a flat type loader unit. The display assembly <NUM> is loaded on a flat type chuck <NUM> by the lift pins <NUM>. A plurality of holes <NUM> may be disposed in the flat chuck <NUM>, and a vacuum may be formed through the holes <NUM> to fix the display assembly <NUM> to a surface of the chuck <NUM>.

Meanwhile, holes are disposed in the flat chuck <NUM> to allow the lift pins <NUM> to move vertically and horizontally. The lift pins <NUM> may transfer the display assembly <NUM> onto the flat chuck <NUM> through the holes disposed in the flat chuck.

In a state in which the display assembly <NUM> is fixed on the flat chuck <NUM>, the adhesive <NUM> is applied to an edge of the display assembly <NUM>. Then, subsequent to releasing the vacuum formed in the flat chuck <NUM>, the lift pins <NUM> ascend.

Then, referring to <FIG>, the display assembly <NUM> is transferred to a curved jig <NUM>. At this time, two types of lift pins 720a and 720b may be utilized. Specifically, the display assembly <NUM> is transferred onto the curved jig <NUM> by the first and second lift pins 720a and 720b. Here, the first lift pin 720a comes into contact with a central portion of the display assembly <NUM>, and the second lift pin 720b comes into contact with an edge of the display assembly <NUM>. Meanwhile, each of the first and second lift pins 720a and 720b may include a vacuum suction pad that is vacuum-sucked to the display assembly <NUM>. A vacuum is formed in the vacuum suction pad to fix the display assembly <NUM> when the first and second lift pins 720a and 720b transfer the display assembly <NUM>.

Holes are disposed in the curved jig <NUM> to allow the lift pins to move vertically and horizontally. The curved jig <NUM> is a frame for processing the display assembly <NUM> into a curved surface.

Subsequent to transferring the display assembly <NUM> onto the curved jig <NUM>, the first and second lift pins 720a and 720b descend. Here, the first and second lift pins 720a and 720b descend until the display assembly <NUM> comes into contact with an uppermost portion of the curved jig <NUM>.

Then, referring to <FIG>, when the display assembly <NUM> comes into contact with the uppermost portion of the curved jig <NUM>, the first lift pin 720a stops descending, and a vacuum is formed through a vacuum hole <NUM> disposed in the curved jig <NUM>. Accordingly, the display assembly <NUM> is bent. The second lift pin 720b descends together with the display assembly <NUM> according to a bending speed of the display assembly <NUM>. At this time, the vacuum suction pad provided on the second lift pin 720b maintains a suction force, thereby providing an additional physical force to the display assembly <NUM>. That is, in the present disclosure, the display assembly <NUM> is physically bent using a suction force formed by a curved jig <NUM> and a suction force formed by the second lift pin 720b.

When the display assembly <NUM> is completely bent, the first and second lift pins 720a and 720b descend to be completely separated from the display assembly <NUM>. At this time, in order to prevent the display assembly <NUM> from being bent in reverse, the clamp C1 may be mounted at an edge of the display assembly <NUM>.

Then, referring to <FIG>, the backlight unit <NUM> is coupled to a position to which the adhesive <NUM> is applied. Then, subsequent to mounting the clamp C2 such that the backlight unit <NUM> and the display assembly <NUM> are strongly coupled to each other, the adhesive <NUM> is cured.

Then, referring to <FIG>, the display assembly <NUM> on which the backlight unit <NUM> is mounted is separated from the curved jig <NUM>. At this time, the clamps mounted on the display assembly <NUM> and the backlight unit <NUM>, respectively, may be sequentially separated therefrom. The backlight unit <NUM> assists in maintaining the display assembly <NUM> in a bent state.

According to the foregoing method, a roll lamination process may be performed when a display and a cover glass are in a flat state, and thereby it is not required to design a lamination process for a curved surface. Accordingly, as shown in <FIG>, a method for manufacturing a curved display device according to the present disclosure may be utilized for producing an instrument panel for a vehicle that requires display devices <NUM> and <NUM> having various curvatures.

Claim 1:
A method of manufacturing a curved display device, the method comprising:
coupling a flat display (<NUM>), an optical clear adhesive (<NUM>), and a flat cover glass (<NUM>) to manufacture a flat display assembly (<NUM>);
applying an adhesive (<NUM>) to an edge of the flat display assembly (<NUM>);
seating the flat display assembly (<NUM>) on a curved jig (<NUM>);
sucking the flat display assembly (<NUM>) to a surface of the curved jig (<NUM>) using a vacuum hole (<NUM>) disposed in the curved jig (<NUM>) to bend the flat display assembly (<NUM>); and
coupling a backlight unit (<NUM>) to a region to which the adhesive (<NUM>) is applied,
wherein the coupling of a backlight unit (<NUM>) to a region to which the adhesive is applied comprises curing the adhesive (<NUM>) while the backlight unit (<NUM>) is pressed to the display assembly so as to maintain a bent state of the display assembly.