Roll printing device, rolling printing method and method for manufacturing liquid crystal display device using the same

A roll printing device, a roll printing method, and a method for manufacturing a liquid crystal display device using the same. The roll printing device includes a dispenser; an anilox roll to receive a designated material dispensed by the dispenser; a printing roll engaged with the anilox roll to rotate with the printing roll to receive the designated material supplied from the anilox roll; and a substrate stage fixed below the printing roll for mounting a substrate. The printing roll is movable on the substrate stage to deposit the designated material on the substrate.

This application claims the benefit of Korean Patent Application No. P2005-0133129, filed Dec. 29, 2005, which is hereby incorporated by reference for all purposes as if fully set forth herein. This application incorporates by reference co-pending application Ser. No. 10/184,096, filed on Jun. 28, 2002 entitled “SYSTEM AND METHOD FOR MANUFACTURING LIQUID CRYSTAL DISPLAY DEVICES FROM LARGE MOTHER SUBSTRATE PANELS”; and co-pending application Ser. No. 11/476,919, filed on Jun. 29, 2006, entitled “METHODS OF MANUFACTURING LIQUID CRYSTAL DISPLAY DEVICES” for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a roll printing device for depositing an orientation film of a liquid crystal display device, and more particularly, to a roll printing device, which is applied to a large-sized substrate.

2. Discussion of the Related Art

Among various ultra-thin flat type display devices, which include a display screen having a thickness of no more than several centimeters, liquid crystal display (LCD) devices are widely used for notebook computers, monitors, aircraft, etc. because they have advantages such as low power consumption and portability.

A typical liquid crystal display device includes upper and lower substrates separated by a designated interval and opposite to each other, with a liquid crystal layer interposed between the upper and lower substrates. The orientation of the liquid crystal layer is controlled by the presence or absence of a voltage applied between the upper and lower substrate. Because of an anisotropic property of the liquid crystal, light transmittance through the liquid crystal changes with changes in the orientation of the liquid crystal layer, allowing the liquid crystal display device to produce an image.

When the orientation of the liquid crystal layer is not uniform, it is difficult to obtain the desired image. Accordingly, an orientation film for uniformly maintaining initial orientation state of the liquid crystal layer is formed on the upper and lower substrates.

The orientation direction of the orientation film may be established using a rubbing method or a light irradiating method.

In the rubbing method, a thin orientation film is deposited on a substrate, and a rubbing roll onto which a rubbing cloth is wound is rolled on the orientation film, thereby orienting the orientation film in a designated direction.

In the light irradiating method, a thin orientation film is deposited on a substrate, and ultraviolet rays, such as polarized rays or non-polarized rays, are irradiated onto the orientation film. A reaction resulting from the irradiation orients the orientation film in a designated direction.

When using either the rubbing or the light irradiating method, an orientation film having a small thickness is uniformly deposited on a substrate. A related art roll printing method is used to deposit the orientation film.

Hereinafter, with reference to the accompanying drawings, a roll printing method according to a related art will be described.

FIG. 1is a schematic sectional view illustrating a method for depositing an orientation film using a related art roll printing device.

Before describing the process for depositing the orientation film using the roll printing device is described, the structure of the roll printing device of the related art will be described.

As shown inFIG. 1, a roll printing device of the related art includes a roll printing unit1and a substrate stage unit3.

The roll printing unit1includes a dispenser14, a doctor roll16, an anilox roll18, and a printing roll20.

The doctor roll16engages the anilox roll18, and the anilox roll18engages the printing roll20.

A printing mask22having a shape corresponding to the deposition pattern of a desired orientation material15is attached to the printing roll20.

The substrate stage unit3includes a substrate stage12, and a substrate10mounted on the substrate stage12.

Hereinafter, a method for depositing or forming an orientation film using the above roll printing device is described. First, the dispenser14supplies or dispenses the orientation material15to the anilox roll18. The orientation material15supplied to the anilox roll18is uniformly spread by the doctor roll16engaged with the anilox roll18, and is then deposited onto the printing mask22attached to the printing roll20. The above process is performed by respectively rotating the doctor roll16, the anilox roll18, and the printing roll20in directions indicated by respective arrows.

The substrate stage12, on which the substrate10is mounted, moves in a direction indicated by an arrow under the printing roll20. While the substrate stage12moves, the substrate10mounted on the substrate stage12and the printing mask22attached to the printing roll20contact each other and the orientation material15deposited onto the printing mask22forming a thin film of orientation material15on the printing mask. As the printing mask22rotates in contact with the substrate10, the thin film of orientation material15on the printing mask22is transcribed onto the substrate10.

In the above-described roll printing device of the related art, the roll printing unit1is fixed and the substrate stage unit3moves, thus allowing the orientation material15to be deposited on the substrate10.

However, when forming an orientation layer on a large sized substrate, the movement of the substrate stage unit3during forming the orientation layer is increased, thereby increasing the space occupied by the roll printing device, and lowering space utilization.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a roll printing device for depositing or forming an orientation film of a liquid crystal display device, a roll printing method, and a method for manufacturing a liquid crystal display device using the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An advantage of the present invention is to provide a roll printing device, which reduces a space occupied thereby when the roll printing device is applied to a large-sized substrate, thus increasing space utilization.

Another advantage of the present invention is to provide a roll printing method, which reduces a space occupied by a roll printing device when the roll printing method is applied to a large-sized substrate, thus increasing space utilization.

Another advantage of the present invention is to provide a method for manufacturing a liquid crystal display device using the roll printing method.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, roll printing device includes: a dispenser; an anilox roll to receive a designated material dispensed by the dispenser; a printing roll engaged with the anilox roll to rotate therewith to receive the designated material supplied from the anilox roll; and a substrate stage fixed below the printing roll to mount a substrate thereon, wherein the printing roll is movable on the substrate stage to deposit the designated material on the substrate.

In another aspect of the present invention, a roll printing method includes dispensing a designated material on a rotating anilox roll using a dispenser; supplying the designated material from the anilox roll to a printing roll engaged with the anilox roll and to rotate therewith; and moving the printing roll to deposit the designated material on a substrate mounted on a substrate stage.

In yet another aspect of the present invention, a method for manufacturing a liquid crystal display device includes preparing a lower substrate and an upper substrate; depositing an orientation film on at least one of the lower and upper substrates; and forming a liquid crystal layer between the two substrates, wherein the depositing of the orientation film is performed using the above roll printing method.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to an embodiment of the present invention, example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Rolling printing device and roll printing method will be described hereinafter.

FIG. 2is a schematic perspective view of a roll printing device in accordance with a first embodiment of the present invention.

The roll printing device illustrated inFIG. 2includes a dispenser, an anilox roll100, a printing roll200, and a substrate stage300.

The dispenser serves to dispense a designated material to the anilox roll100.

The anilox roll100serves to transfer the designated material, dispensed by the dispenser, onto the printing roll200. The anilox roll100is supported by an anilox roll frame120.

The printing roll200serves to receive the designated material supplied to the anilox roll100, and then to move on the substrate stage300to deposit the designated material on a substrate mounted on the substrate stage300. The printing roll200is supported by a printing roll frame220.

A motor240is connected to the printing roll frame220supporting the printing roll200. The printing roll200moves by the operation of the motor240.

As shown inFIG. 2, the printing roll200is separated from the anilox roll100and moves across the substrate stage300to engage the printing roll200. When the anilox roll100engages the printing roll200, the printing roll200can be rotated to receive the designated material from the anilox roll100. After receiving the designated material from the anilox roll100, the printing roll is moved across the substrate stage300, separating from the anilox roll100and depositing the designated material on the substrate mounted on the substrate stage300.

The substrate stage300serves to mount the substrate thereon. The substrate stage300is supported by a substrate stage frame320which is maintained in a fixed position.

The roll printing device may further include a doctor roll engaging the anilox roll100and rotating therewith to order to uniformly spread the designated material from the anilox roll to the printing roll200. Alternatively, a doctor blade150contacting the anilox roll100may be used to uniformly spread the designated material.

Hereinafter, a roll printing method using the roll printing device of the first embodiment will be described.

First, the dispenser dispenses the designated material to the rotating anilox roll100.

Thereafter, the anilox roll100supplies the designated material to the printing roll200, engaged with the anilox roll and rotated therewith.

The dispensing of the designated material to the anilox roll100and the supply of the designated material from the anilox roll100to the printing roll200may be simultaneously performed.

By using a doctor roll engaged with the anilox roll100and rotated therewith, or by using a doctor blade contacting the anilox roll100, the designated material supplied from the anilox roll100to the printing roll200can be uniformly spread onto the printing roll200.

Thereafter, the printing roll200moves along the substrate stage depositing the designated material on the substrate mounted on the substrate stage300.

By moving the printing roll200rather than the substrate stage300, the space occupied by the roll printing device is not increased when the size of the substrate is increased.

FIG. 3is a schematic perspective view of a roll printing device in accordance with a second embodiment of the present invention;FIG. 4Ais a schematic sectional view of the roll printing device in accordance with the second embodiment, showing vibration dampeners disconnected from the roll printing device; andFIG. 4Bis a schematic sectional view of the roll printing device in accordance with the second embodiment showing the vibration dampeners connected to the roll printing device.

The roll printing device of the second embodiment is the same as the roll printing device of the first embodiment except that the roll printing device of the second embodiment further includes a vibration dampener for preventing or reducing the generation of vibration when an anilox roll and a printing roll are engaged with each other and rotated. Accordingly, parts included in the second embodiment that are substantially the same as those in the first embodiment, are denoted by the same reference numerals even though they are depicted in different drawings.

As shown inFIG. 3, the roll printing device in accordance with the second embodiment includes a dispenser, an anilox roll100, a printing roll200, a substrate stage300, and a vibration dampener.

The dispenser, the anilox roll100, the printing roll200, and the substrate stage300of this embodiment are the same as those of the first embodiment, and a detailed description thereof will be thus omitted.

The vibration dampener includes a horizontal vibration dampener400and a vertical vibration dampener500.

The horizontal vibration dampener400includes a first structure400aformed on the printing roll frame220supporting the printing roll200, and a second structure400bformed on the substrate stage frame320supporting the substrate stage300. When the first structure400aand the second structure400bare engaged, horizontal vibration of the printing roll200is prevented or reduced.

The first structure400ahas a shape having a curved surface and the second structure400bhas a shape including an inclined surface. For example, the first structure may have a spherical shape while the second structure400bmay have a triangular shape.

InFIG. 3, the first structure400ais shown as formed on an outer surface of the printing roll frame220, and the second structure400bis formed on an outer surface of the substrate stage frame320. However, the first structure400amay be formed on the inner surface of the printing roll frame220, and the second structure400bmay be formed on the inner surface of the substrate stage frame320.

The vertical vibration dampener500includes a third structure500aformed on the printing roll frame220supporting the printing roll200, and a fourth structure500bformed on the substrate stage frame320supporting the substrate stage300. When the third structure500aand the fourth structure500bare connected, vertical vibration of the printing roll200is prevented or reduced. The third structure500ahas a projection or a recess shape, and the fourth structure500bhas a recess or a projection shape. More particularly, the shapes of the third structure500aand the fourth structure500bare complementary. When the third structure500ahas a projection shape, the fourth structure500bhas a recess shape, and when the third structure500ahas a recess shape, the fourth structure500bhas a projection shape. For the purposes of illustration, inFIG. 3the third structure500ais shown as a projection having a triangular shape while the fourth structure500bis shown as a recess having a triangular shape. The third structure500aand the fourth structure500bmay have other complementary or engaging shapes.

InFIG. 3, the third structure500ais illustrated as formed on the outer surface of the printing roll frame220, and the fourth structure500bis illustrated as formed on the outer surface of the substrate stage frame320. However, the third structure500amay be formed on the inner surface of the printing roll frame220, and the fourth structure500bmay be formed on the inner surface of the substrate stage frame320.

Hereinafter, with reference toFIGS. 4A and 4B, a method for reducing horizontal vibration of the printing roll200through the engagement of the first structure400aand the second structure400band a method for reducing vertical vibration of the printing roll200through the connection of the third structure500aand the third structure500bwill be described.

First, the method for reducing horizontal vibration of the printing roll200is described.

As shown inFIG. 4A, the first structure400ahaving the shape of a spherical bearing is formed on the printing roll frame220, and the second structure400bhaving a triangular shape is formed on the substrate stage frame320.

As shown inFIG. 4B, the second structure400bmoves upward and the inclined surface of the second structure400bcontacts the curved surface of first structure400a, thereby preventing or reducing horizontal vibration of the printing roll200.

The engagement of the first and second structures400aand400bof the horizontal vibration dampener is performed when the printing roll200and the anilox roll100are engaged with each other and rotated therewith while a designated material is supplied from the anilox roll100to the printing roll200. After supply of the designated material to the printing roll200is completed, the second structure400bmoves downwardly and separates from the first structure400ato allow the printing roll200to be separated from the anilox roll100as illustrated inFIG. 4A. The anilox roll100moves on the substrate stage300, depositing the designated material on a substrate mounted on the substrate stage300.

Next, the method for reducing vertical vibration of the printing roll200is described.

As shown inFIG. 4B, the third structure500ahaving a projection shape is formed on the printing roll frame220, and the fourth structure500bhaving a recess shape is formed on the substrate stage frame320.

As shown inFIG. 4B, the fourth structure500bis rotated to contact the third structure500a, thereby preventing or reducing vertical vibration of the printing roll200. If the third structure500aand the fourth structure500bhave complementary shapes, the third structure500aand the fourth structure500bmay fit together to engage each other when contacting each other.

The connection of the third and fourth structures500aand500bof the vertical vibration dampener is performed when the printing roll200and the anilox roll100are engaged with each other and rotated therewith so that the designated material is supplied from the anilox roll100to the printing roll200. Thereafter, the fourth structure500bis rotated and separated from the third structure500ato allow the printing roll200to separate from the anilox roll100. The printing roll200moves on the substrate stage300depositing the designated material on the substrate mounted on the substrate stage300.

Hereinafter, a roll printing method using the roll printing device of the second embodiment will be described.

First, the printing roll200is fixed to prevent or reduce vibration.

The fixation of the printing roll200is performed by at least one of the method for reducing horizontal vibration of the printing roll200and the method for reducing vertical vibration of the printing roll200.

That is, the printing roll200is fixed using at least one of the method for reducing horizontal vibration of the printing roll200by engaging the first structure400ahaving the curved surface formed on the printing roll frame220with the second structure400bhaving the inclined surface formed on the substrate stage frame320and the method for reducing vertical vibration of the printing roll200by connecting the third structure500ahaving the projection or recess shape formed on the printing roll frame220and the fourth structure500bhaving the recess or projection shape formed on the substrate stage frame320.

Once the printing roll is fixed, the dispenser supplies the designated material to the rotating anilox roll100.

The anilox roll100supplies the designated material to the printing roll200, which is engaged with the anilox roll100and rotated therewith.

The dispensing of the designated material to the anilox roll100and the supply of the designated material from the anilox roll100to the printing roll200may be performed simultaneously.

By using the doctor roll engaged with the anilox roll100and rotated therewith, or the doctor blade contacting the anilox roll100, the designated material is uniformly supplied to the printing roll200from the anilox roll100.

Thereafter, the fixation of the printing roll200is released.

The release of the fixation of the printing roll200is performed by releasing the connection performed by the method for reducing horizontal vibration of the printing roll200or the method for reducing vertical vibration of the printing roll200.

That is, when the fixation of the printing roll200is performed by the horizontal vibration reducing method, the fixation of the printing roll200may be released by releasing the engagement of the first structure400ahaving the curved surface formed on the printing roll frame220and the second structure400bhaving the inclined surface formed on the substrate stage frame320.

When the fixation of the printing roll200is performed by the vertical vibration reducing method, the fixation of the printing roll200may be released by releasing the connection of the third structure500ahaving the projection or recess shape formed on the printing roll frame220and the fourth structure500bhaving the recess or projection shape formed on the substrate stage frame320.

Thereafter, the printing roll200moves on the substrate stage depositing the designated material on the printing roll200onto the substrate mounted on the substrate stage300.

By moving the printing roll200rather than the substrate stage300, the space occupied by the roll printing device does not increase when the size of the substrate is increased. Further, by employing the horizontal and vertical vibration dampeners400and500while the printing roll200and the anilox roll100are engaged, vibration of the printing roll200can be eliminated or reduced.

A method for manufacturing liquid crystal display device will be described hereinafter.

First, a lower substrate and an upper substrate are prepared.

The elements for the lower substrate and the upper substrate are appropriately formed and arranged according to the driving mode of the liquid crystal display device.

In particular, when the liquid crystal display device is a Twisted Nematic (TN) mode device, gate lines and data lines that cross substantially perpendicularly to define pixel regions on the lower substrate; TFTs (thin film transistors) are formed at the crossings of the gate lines and the data lines to serve as switching elements; and pixel electrodes are formed in the pixel regions and connected to a TFT to serve as electrodes to form an electric field. A light shielding layer to prevent light leakage, color filter layers to form colors; and common electrodes to serve as electrodes to form the electric field are formed on the upper substrate of the TN mode device.

When the liquid crystal display device is an In Plane Switching (IPS) mode device, gate lines and data lines are formed that cross substantially perpendicularly intersect to define pixel regions on the lower substrate; TFTs are formed at the crossings of the gate lines and the data lines to server switching elements; and pixel electrodes and common electrodes are formed in the pixel regions to serve as pairs of electrodes to form an electric field therebetween. A light shielding layer to prevent light leakage and color filter layers to form colors are formed on the upper substrate of the IPS mode device.

Thereafter, an orientation film is deposited on at least one of the lower and upper substrates.

Depositing the orientation film employs the above-described roll printing method, which uses an orientation material as the designated material.

After the deposition of the orientation film, the orientation film is given a uniform orientation direction using a rubbing method or a light irradiating method.

Thereafter, a liquid crystal layer is formed between the lower and upper substrates.

The formation of the liquid crystal layer may be achieved by an injection method or a liquid crystal dispensing or dropping method.

In the injection method, a sealant is deposited or formed on one of the lower and upper substrates to form a sealant layer having an injection port; the two substrates are bonded to each other; and liquid crystal is injected into a space between the bonded substrates through the injection port.

In the liquid crystal dispensing method, a sealant is deposited or formed on one of the upper and lower substrates; liquid crystal is dropped on one of the upper and lower substrates; and the two substrates are bonded to each other.

As described above, the embodiments of the present invention provide advantages as follows.

First, by moving the printing roll rather than the substrate stage300, the space occupied by the roll printing device does not increase when the size of the substrate is increased.

Secondly, by using the horizontal and vertical vibration dampeners, it is possible to prevent or reduce vibration of the printing roll when the printing roll is engaged with an anilox roll and rotated therewith, facilitating uniform printing of a designated material onto the printing roll.