WO2010076903A1

WO2010076903A1 - Touch screen window for applying to display panel such as lcd panel and method for preparing the same

Info

Publication number: WO2010076903A1
Application number: PCT/KR2008/007742
Authority: WO
Inventors: Dug-Kyu Kim
Original assignee: Dug-Kyu Kim
Priority date: 2008-12-29
Filing date: 2008-12-29
Publication date: 2010-07-08

Abstract

Disclosed herein is a touch screen window installed on a liquid crystal Display (LCD) panel in order to in order to operate the LCD panel, including a window having a thickness of 200 to 2000 /M, an Ultraviolet (UV) adhesive coating layer uniformly coated on the window, and a film having a electric-resistive value and a thickness of 200 to 2000 /M, as a film adhered on the UV adhesive coating layer. According to the present invention, leveling and lamination are performed simultaneously using liquid UV adhesive, thereby maMng operation process simple as well as dramatically decreasing percent defective.

Description

TOUCH SCREEN WINDOW FOR APPLYING TO DISPLAY PANEL SUCH AS LCD PANEL AND METHOD FOR PREPARING THE SAME

Technical Field

[1] The present invention relates to a touch screen window applied to a display panel, such as an LCD panel, and method of manufacturing the same. Background Art

[2] An LCD stands for a liquid crystal display, and is configured such that a liquid crystal material is injected into a space between two glass substrates, i.e., two LCD panels. Thus, when an electrical pressure is applied between the liquid crystal material, arrangement of respective liquid crystal molecules is changed. At this time, a variety of characters or images are displayed on the LCD panel depending on a variation of the optical refractive index. Since such an LCD is typically driven with a power source of 1.5 to 2 V and has a very lower power consumption, it is widely used in PDAs, MP3s, computer monitors, TV sets and so forth.

[3] Meanwhile, an LCD window refers to a transparent protective window that is mounted on the outer surface of the LCD panel so as to protect the LCD panel from an external impact. This LCD window is mainly composed of a synthetic resin substrate containing a synthetic resin such as acryl resin, polycarbonate (PC), polyethylene terephthalate (PET), etc. Currently, along with the development of a digital industry, the technology relating to the LCD panel and the LCD window follow a trend toward slimness while various digital electronic devices are made more compact and slimmer.

[4] In line with this trend, conventionally, various researches have been attempted on development to implement a desired thickness while laminating a window and a film having electrical characteristics because the thickness of the substrate is restricted to be thin as possible. There has been caused a problem in that interference fringe phenomenon which is created at the time of overlapping of two or periodic patterns, and in that interference fringes occur due to positive and negative parts, and bubbles are generated.

Disclosure of Invention Technical Problem

[5] Accordingly, the present invention has been made keeping in mind the afore- mentioned problems occurring in the prior art, and an object of the present invention is to provide a touch screen window in which a liqiid UV adhesive is coated over an LCD panel to adhere a film having electrical characteristics to a window, so that it is possible to effectively protect the LCD panel from an external impact despite of its thin thickness and minimize interference fringe phenomenon, particularly, so that there is no bubbles between a window layer and a film layer having electrical characteristics and its transparency and adhesive strength are significantly superior when the window and the film having electrical characteristics are laminated, and a method of manufacturing the same. Technical Solution

[6] In order to accomplish the above objects, the present invention provide a touch screen window installed on a liquid crystal Display (LCD) panel in order to operate the LCD panel, including a window having a thickness of 200 to 2000 μm, an Ultraviolet (UV) adhesive coating layer uniformly coated on the window, and a film having a electric-resistive value and a thickness of 200 to 2000 μm, as a film adhered on the UV adhesive coating layer. In this case, a film can be replaced with glass having a resistance value.

[7] According to a preferred embodiment of the present invention, the window is synthetic resin or tempered glass.

[8] According to a preferred embodiment of the present invention, the UV adhesive is an acryl- based or epoxy-based UV adhesive.

[9] Furthermore, the present invention provides a method of manufacturing a touch screen window installed on a liquid crystal Display (LCD) panel in order to operate the LCD panel, comprising: (a) preparing a window having preferably a thickness of 200 to 2000 μm, and a film having preferably a thickness of 200 to 2000 μm and an electric- resistance value; (b) uniformly coating the UV adhesive on the window or film from step (a) or on both with a thickness of 5 to 50/M, and adhering the window and the film to each other to provide a lamination structure of the window and the film; (c) applying pressure to the laminated structure from step (b) subsequently and continuously from a longitudinal center of the laminated structure to its outside; (d) curing a product from step (c) through UV radiation (e) washing the cured product from step (e).

[10] The UV adhesive used in step (b) is preferably an acryl- based or epoxy-based UV adhesive.

[11] In step (c), a roller having a structure which is bended from its center to an outside is preferably used as a means of applying a pressure.

[12] According to a preferred embodiment of the present invention, the roller is formed of elastic solid, and the roller has at an tilt angle (α) of preferably 0 to 5 °, more preferably 0.2 to 5 ° from a contact center of the lamination structure to sides of the roller. Furthermore, the roller is operated in a unit of mm and a unit of μm independently.

Advantageous Effects

[13] It is expected that the LCD window according to the present invention effectively protects an LCD panel from an external impact thereby proving contribution with various digital electronic devices such as PDAs, MP3s, computer monitors, TV sets and so forth.

[14] Furthermore, the method of manufacturing the touch screen window keeps its thickness uniform, compared to a conventional method of attaching a tape only to the side or front of a window, and micro bubbles do not remain inside an adhesive layer at all and, interference fringe phenomenon, which is generated due to the difference between thicknesses of a window and a film having an electric resistance value, becomes dramatically weaker, compared to a simple compression method. Particularly, there is an advantage that the wrong operation of touch operations decrease dramatically compared to a conventional method. Brief Description of Drawings

[15] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[16] FlG. 1 is a diagram schematically illustrating the lamination structure of a touch screen window according to the present invention;

[17] FlG. 2 is an exploded perspective view illustrating the touch screen window shown in FIG.1;

[18] FIG. 3 is a sectional view along A-A of FIG. 2;

[19] FIG. 4 a diagram schematically illustrating an example of a method of applying pressure to a touch screen window according to a method according to the present invention; and

[20] FIG. 5 is a diagram illustrating a contact angle between a touch screen window and a roller. Best Mode for Carrying out the Invention [21] The present invention is described below in more detail with reference to accompanying drawings.

[22]

[23] HG. 1 illustrates a state before a touch screen window according to the present invention has been manufactured, and HG. 2 schematically illustrates the degree of steps of a film having an electric resistive value.

[24] Referring to HGS. 1 and 2, a touch screen window according to the present invention which installed on an LCD panel in order to operate the LCD panel includes a window having a predetermined thickness, a UV adhesive uniformly coated over the window, a film (hereinafter referred to as a "electric-resistive film") having a resistance value, which is attached to the UV adhesive coating layer.

[25] In the present invention, the window can employ whichever synthetic resin material used to manufacture a conventional window, but preferably employs acryl resin, polycarbonate (PC), polyethylene terephthalate (PET), tempered glass, etc. The thickness of the window can be modified depending on the size of the LCD panel or the characteristics of an electronic device on which the LCD panel is mounted, but preferably is in a range between 200 μm and 2000 μm.

[26] In the present invention, an adhesive for adhering the window and the electric- resistive film to each other effectively bonds well to the window and the electric- resistive film when its surface energy is designed to be close to their surface energies, and may be any adhesive which prevents bubbles from being generated within the adhesive layer and does not disturb the reflective index and transparency of the entire window.

[27] The UV adhesive is an anaerobic adhesive which is so-called an ultraviolet (UV) curing adhesive. This UV adhesive typically maintains a liquid phase prior to curing and allows an photeπnitiator contained in the adhesive to initiate a reaction at the time of irradiation of an ultraviolet ray to the UV adhesive coating layer thereby being solidified in a short time, and it is very suitable for the window and the electric- resistive film because the surface energies of the window and the electric-resistive film are similar to each order.

[28] The thickness of the UV adhesive coating layer is set to be in a range between 5 to

50 μm. If the thickness of the UV adhesive coating layer is less than 5 μm, the adhesion strength may be weakened. On the contrary, if the thickness of the UV adhesive coating layer is more than 50 μm, there is no increase in the adhesion strength and rather an over flow phenomenon occurs where the adhesive layer material forcibly flow out from the adhesive layer, or there is a possibility that interference fringe phenomenon becomes stronger because micro-bubbles remain in the adhesive layer and it is difficult to uniformly level the coating of the UV adhesive coating layer due to micro foreign material.

[29] Hnally, the thickness of the window layer laminated on the surface of the UV adhesive coating layer is formed of a thin sheet glass having a thickness of 200 to 2000 μm. In this case, if the thickness of the thin sheet glass is less than 200 μm, bending phenomenon become stronger, so that the function as a tempered glass may not be worked. On the contrary, if the thickness of the thin sheet glass is more than 2000 μm, the thickness of the entire LCD window is increased very greatly, undesirably leading to go against a slimness trend of the LCD.

[30] In the meantime, a method of manufacturing the touch screen window according to the present invention will be described hereinafter in detail.

[31] Hrst, a window having a thickness of 200 to 2000 μm, and a film having a thickness of 200 to 2000 μm and an electric-resistance value are prepared. In this case, the film may be fabricated in the size which is larger or smaller a little than the window such that the film (electric-resistive layer) having an electric resistive value is adhered only to parts of synthetic resin having a predetermined size and a predetermined thickness and tempered glass.

[32] Next, a UV adhesive is coated on any one surface or both surfaces of the window or the electric-resistive film. In this case, a coating method may be performed such that the window or the electric-resistive film is fixed on a jig inside a clean room, and then the UV adhesive is coated thereon by a dispenser or silk printing. In the silk printing method, it is possible to uniformly regulate a coating thickness. However, it is difficult to remove micro bubbles in a subsequent process. In this case, the loss of the adhesive is low. In the case of using dispenser, the adhesive is coated at a fixed location, micro bubbles are eliminated while the thickness of the adhesive is regulated using the roller. In the case of using the dispenser, another advantage is to be very benefit in selection of locations. As a result, the workability and convenience are acquired. Preferably, the UV adhesive is uniformly coated with a thickness of 5 to 50/M. It should be noted that the UV adhesive should not be exposed to UV rays. In the present invention, as the UV adhesive, an UV adhesive having viscosity of 100 to 6000 cps preferably is used.

[33] Subsequently, pressure is applied to the laminated structure of the touch screen window from the above-described process. In this case, the pressure is applied to the laminated structure subsequently and continuously from the longitudinal center of the laminated structure to its outside. In order to apply the pressure to the laminated structure subsequently and continuously from the longitudinal center of the laminated structure to the outside, a roller whose center is bended to its outside is used (show HG. 5). More particularly, it is preferable that the used roller have a center which is higher than its sides rather than to be flat. The reason for this is that vertical pressure applied to the roller is not uniform. In order to solve this problem, the roller should be manufactured such that the roller is formed of elastic solid, the center of the roller is tilted at an tilt angle of 0.2 to 5 ° from the sides of the roller (show HG. 5). Furthermore, the roller is preferably operated in a unit of mm and a unit of μm independently for the convenience of operation and the perfection of coating.

[34] Hnally, an ultraviolet (UV) light is irradiated to the UV adhesive coating layer, from which the micro-bubbles are completely removed, thereby curing the UV adhesive coating layer. In this case, the luminance or energy amount of the UV rays varies depending on the thickness of the UV adhesive coating layer. Preferably, the ultraviolet (UV) rays are irradiated to the UV adhesive coating layer with luminance of 50 to 500 mW for enough time such that photeπnitiator are completely to be reacted. Ibr example, in a condition in which curing is performed, if energy of 1000 mJ is required, time of more than 20 seconds is required at luminance of 50 mW, but time of more than 10 seconds is enough at luminance of more than 100 mW. Then, the UV adhesive coating layer is completely cured, thereby completing the touch screen window through lamination of a window and a film having electric-resistive characteristics according to the method of manufacturing a touch screen window according to the present invention.

[35] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] A touch screen window installed on a liquid crystal Display (LCD) panel in order to operate the LCD panel, comprising: a window; an Ultraviolet (UV) adhesive coating layer uniformly coated on the window; a film having a electric-resistive value as a film adhered on the UV adhesive coating layer.

[2] The touch screen window as set forth in claim 1, wherein a thickness of the window is in a range between 200 /M and 2000 /M, and the thickness of the film is in a range between 200 μm and 2000 μm.

[3] The touch screen window as set forth in claim 1, wherein the window is synthetic resin or tempered glass.

[4] The touch screen window as set forth in claim 1, wherein the UV adhesive is an acryl- based or epoxy-based UV adhesive.

[5] The touch screen window as set forth in claim 1, wherein the UV adhesive has viscosity of 100 to 6000 cps.

[6] A method of manufacturing a touch screen window installed on a liquid crystal

Display (LCD) panel in order to operate the LCD panel, comprising:

(a) preparing a window having preferably a thickness of 200 to 2000 μm, and a film having preferably a thickness of 200 to 2000 μm and an electric-resistance value;

(b) uniformly coating the UV adhesive on the window or film from step (a) or on both with a thickness of 5 to 50/M, and adhering the window and the film to each other to provide a lamination structure of the window and the film;

(c) applying pressure to the laminated structure from step (b) subsequently and continuously from a longitudinal center of the laminated structure to its outside;

(d) curing a product from step (c) through UV radiation

(e) washing the cured product from step (e).

[7] The method as set forth in claim 6, wherein the UV adhesive used in step (b) is an acryl- based or epoxy-based UV adhesive.

[8] The method as set forth in claim 6, wherein, in step (b), coating using the UV adhesive is performed by a dispenser.

[9] The method as set forth in claim 6, wherein the UV adhesive used in step (b) has viscosity of 100 to 6000 cps.

[10] The method as set forth in claim 6, wherein, in step (c), a roller having a structure which is bended from its center to an outside is used as a means of applying a pressure.

[11] The method as set forth in claim 10, wherein the roller is formed of elastic solid, and the roller has at an tilt angle (α) of preferably 0 to 5 °, more preferably 0.2 to 5 ° from a contact center of the lamination structure to sides of the roller.

[12] The method as set forth in claim 10, wherein the roller is operated in a unit of mm and a unit of μm independently.