KR20040017139A - Image display device combined touch panel and method for manufacturing thereof - Google Patents

Abstract

PURPOSE: A touch panel integrating LCD and a method for fabricating the same are provided to integrate a touch panel with an image display device for removing a lower substrate of the touch panel by forming a first transparent electrode of the touch panel to an upper surface of the image display device. CONSTITUTION: A touch panel integrating LCD includes an LC panel(200) and a touch panel(300). The touch panel has a first transparent electrode(310) formed on an upper substrate(230) of the LC panel, dot spacers(320) formed on the first transparent electrode, and a touch panel upper substrate(330) apart from the first transparent electrode by a predetermined distance. The touch panel upper substrate includes an optical film(350), a second transparent electrode(360) formed on the optical film facing the first transparent electrode, and a second polarization plate(340) formed on a surface of the optical film, the surface being not formed with the second transparent electrode. The touch panel upper substrate is coupled with the LC panel by an adhesive agent(370) provided along the edge of the second transparent electrode. The adhesive agent is stuck to the first transparent electrode to keep a distance between the first and second transparent electrode.

Description

Touch panel integrated image display device and manufacturing method thereof {IMAGE DISPLAY DEVICE COMBINED TOUCH PANEL AND METHOD FOR MANUFACTURING THEREOF}

The present invention relates to a touch panel integrated image display device and a method for manufacturing the same, and more particularly, to a touch panel integrated image display device and a method for manufacturing the same, which can reduce the thickness of the product and lower the manufacturing cost.

In general, a touch panel is a device capable of contacting a person's hand or an object with a character or a specific position displayed on the screen by an image display device without using a keyboard, and identifying the position and performing specific processing by stored software. Say.

The touch panel is mainly operated by the contact capacitive method, the pressure resistive film method, the infrared sensing method, the integral tension measurement method, the surface ultrasonic conduction method and the piezo effect method. Let's take a quick look at the touch panel.

The pressure resistive touch panel is formed on two transparent substrates so as to face transparent electrodes having resistance components at regular intervals. When a current is applied to the transparent electrodes, a voltage is applied to each of the transparent electrodes by the resistance component, and when the hands are touched, the two transparent electrodes are in contact with each other. Therefore, the resistance components of the two transparent electrodes form a parallel connection of the resistors, and the resistance value changes. At this time, the voltage changes due to the current flowing through both transparent electrodes. This is how you know where you are in contact.

The liquid crystal display, which is one of the image display devices, applies an electric field to a liquid crystal material having an anisotropic dielectric constant injected between an array substrate and a color filter substrate, which is a thin film transistor substrate, and the intensity of the electric field. The display device obtains a desired image signal by controlling the amount of light transmitted through the substrate. Hereinafter, a touch panel image display apparatus will be described using an LCD as an example of an image display apparatus as an example.

1 is a cross-sectional view illustrating a conventional touch panel liquid crystal display device.

Referring to FIG. 1, the touch panel liquid crystal display device 10 is largely comprised of a liquid crystal display device and a touch panel 30 combined on the liquid crystal display panel 20 included in the liquid crystal display device.

Next, the liquid crystal display device will be described below with a liquid crystal display panel.

The liquid crystal display panel 20 includes a lower substrate 21 having a thin film transistor (not shown), and a color filter (not shown) facing the lower substrate 21 and facing a surface where the thin film transistor is provided. The upper substrate 23 and the liquid crystal 25 enclosed therebetween.

In the liquid crystal display panel 20, a first polarizing plate 26 for converting light incident from the backlight assembly (not shown) into the liquid crystal display panel 20 into linearly polarized light is formed on the surface on which the thin film transistor of the lower substrate 21 is formed. The second polarizing plate 27 is provided on the opposite side, and the second polarizing plate 27 is provided on the side opposite to the side on which the color filter of the upper substrate 23 is formed.

The touch panel 30 may include a first substrate 31 provided on the second polarizing plate 27 of the liquid crystal display panel 20 and a second substrate spaced apart from the first substrate 31 by a predetermined distance ( 34 and first and second transparent electrodes 32 and 35 formed on respective surfaces of the first and second substrates 31 and 34.

A plurality of dot spacers 33 having a height smaller than the distance between the first and second transparent electrodes 32 and 35 are formed on the first transparent electrode 32.

The first substrate 31 of the touch panel 30 is made of a transparent material to transmit a predetermined image provided from the liquid crystal display panel 30, and the second substrate 34 is made of polycarbonate or the like. A special optical film made of a material having an optically isotropic refractive index of is used.

In the touch panel liquid crystal display device 10 described above, the first substrate 31 of the touch panel 30 and the upper substrate 23 of the liquid crystal display panel 20 are disposed on the boundary of the second polarizing plate 27. Each is provided. Therefore, light provided from the lower side of the liquid crystal display panel 20 or light incident from the outside must pass through the upper substrate 23 of the liquid crystal display panel 20 and the first substrate 31 of the touch panel 30, respectively. Loss of light is caused, and the use of transparent substrates for the liquid crystal display panel 20 and the touch panel 30 increases the overall thickness of the product and increases the manufacturing cost.

Accordingly, the technical problem to be solved by the present invention is to solve the above problems, and an object of the present invention is to integrate the touch panel and the image display device, thereby reducing the thickness of the product and lowering the manufacturing cost. To provide.

Further, another object of the present invention is to provide a method of manufacturing the touch panel integrated image display apparatus.

1 is a view for explaining a conventional touch panel liquid crystal display device.

2 is a cross-sectional view for describing a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention.

FIG. 3A is a view illustrating an operating state of a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention, and FIG. 3B is an enlarged view of part A of FIG. 3A.

4A is a conceptual diagram of an antireflection film, and FIG. 4B is a view for explaining a hard coating film and an antireflection film.

5A to 5E are views for explaining a manufacturing process of a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention.

6A to 6C are views for explaining the manufacturing process of the dot spacer shown in FIG. 5D.

<Description of Symbols for Main Parts of Drawings>

100: touch panel integrated liquid crystal display device 210: lower substrate

230: upper substrate 250: liquid crystal

260: first polarizing plate 320: dot spacer

340: second polarizing plate

According to one aspect of the present invention, there is provided a touch panel integrated image display device comprising: a first transparent electrode formed on an upper portion of an image display device displaying a predetermined image; A plurality of dot spacers formed on the first transparent electrode; An optical film spaced apart from the first transparent electrode by a predetermined interval; A second transparent electrode which is integrally formed under the optical film so as to face the first transparent electrode and detects position information by contacting the first transparent electrode; And a polarizing plate provided on a surface opposite to a surface on which the second transparent electrode of the optical film is formed.

In addition, a method for manufacturing a touch panel integrated image display device according to one aspect for carrying out the other object of the present invention, (a) forming a first transparent electrode on the upper portion of the image display device; (b) forming a dot spacer on the first transparent electrode; (c) a first step comprising a polarizing plate, a second step of forming an optical film on the polarizing plate, and a third step of forming a second transparent electrode on a surface opposite to the surface on which the optical film of the polarizing plate is formed; Forming an upper substrate for the touch panel by the step; And (d) coupling the image display device formed by the step (b) and the upper substrate for the touch panel formed by the step (d) so that the first transparent electrode and the second transparent electrode face each other. It is done by

According to such a touch panel integrated image display device and a manufacturing method thereof, the first transparent electrode of the touch panel is formed on the upper substrate of the image display device so as to integrate the touch panel and the image display device, thereby reducing the number of parts as a whole. It is possible to reduce the loss of light transmitted through the integrated image display device, reduce the overall thickness of the product, and lower the manufacturing cost of the product.

Hereinafter, a touch panel integrated image display device and a method of manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the touch panel integrated image display device according to the present invention will be described using an LCD as an image display device as an example.

2 is a cross-sectional view illustrating a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention. In particular, FIG. 2 is a cross-sectional view illustrating a touch panel integrated liquid crystal display device in which a liquid crystal display panel and a touch panel are integrally formed.

Referring to FIG. 2, the touch panel integrated liquid crystal display device 100 according to an exemplary embodiment of the present invention may provide a liquid crystal display panel 200 that provides a predetermined image and a backlight assembly that provides light to the liquid crystal display panel 200. And a touch panel 300 integrally formed with the liquid crystal display device.

Hereinafter, the liquid crystal display device will be described with reference to the liquid crystal display panel formed integrally with the touch panel.

In detail, the liquid crystal display panel 200 includes a lower substrate 210 having a thin film transistor (not shown) and an upper substrate having a plurality of color filters (not shown) on one surface facing the lower substrate 210. 230, the liquid crystal 250 encapsulated between the lower substrate 210 and the upper substrate 230, and the first polarizing plate 260 provided below the lower substrate 210.

On the lower substrate 210, a pixel electrode 220 for applying a voltage to drive a liquid crystal 250 to display a predetermined image is applied onto the thin film transistor, and the pixel electrode 220 is disposed on the upper substrate 230. Correspondingly, a common electrode 240 for driving the liquid crystal 250 is applied onto the R, G, and B color filters. The pixel electrode 220 and the common electrode 240 are generally made of indium tin oxide (ITO) or indium zinc oxide (IZO).

The first polarizer 260 serves to change light incident from a backlight assembly (not shown) provided below the liquid crystal display panel 200 to linearly polarized light.

The touch panel 300 includes a first transparent electrode 310 formed on the upper substrate 230 of the liquid crystal display panel 200, a dot spacer 320 formed on the first transparent electrode 210, and a first transparent electrode. The upper panel 330 for the touch panel is spaced apart from the electrode 310 by a predetermined interval.

The upper substrate 330 for the touch panel includes the optical film 350 and the second transparent electrode 360 and the second film of the optical film 350 formed on the optical film 350 to face the first transparent electrode 310. The second polarizing plate 340 is provided on a surface opposite to the surface on which the transparent electrode 360 is formed.

The optical film 350 is made of a material having an optically isotropic refractive index such as polycarbonate.

The upper substrate 330 for the touch panel including the second transparent electrode 360 is formed by the adhesive 370 provided along the edge of the second transparent electrode 360, so that the touch panel upper substrate 330 is the liquid crystal display panel. Combine with 200. In this case, the adhesive 370 is adhered to the first transparent electrode 310 formed on the upper substrate 230 of the liquid crystal display panel 200, and the first transparent electrode 310 and the second transparent electrode 360 are separated by a predetermined interval. In parallel with the role to maintain.

FIG. 3A is a view illustrating an operating state of a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention, and FIG. 3B is an enlarged view of part A of FIG. 3A.

3A and 3B, the touch panel integrated liquid crystal display 100 in which the upper substrate 330 for the touch panel is pressed by the user is illustrated.

In the touch panel integrated liquid crystal display 100, a voltage change should occur when the first transparent electrode 310 and the second transparent electrode 360, each of which current flows, contact each other in order to determine a position indicated by a user. . That is, the touch panel upper substrate 330 is bent by the user's touch, and the second transparent electrode 360 and the first transparent electrode 310 are in contact with each other. As a result, the voltage between the first transparent electrode 310 and the second transparent electrode 360 is changed, so that the position touched by the user can be determined by the voltage change.

Therefore, the user must press the upper substrate 330 for the touch panel so that the second transparent electrode 360 is in contact with the first transparent electrode 310. In this case, the dot spacer 320 is formed on the first transparent electrode 310. ) To alleviate the impact when the second transparent electrode 360 is in contact with the first transparent electrode 310, and to provide a repulsive force to return the upper substrate 330 for the touch panel to its original position when the user releases the hand. It is elastic and is formed of a transparent insulating material so that light transmitted through the liquid crystal display panel 200 is not blocked by the dot spacer 320.

As a result, light transmitted through the upper substrate (not shown) of the liquid crystal display panel 200 is not blocked by the dot spacer 320, and the upper substrate 330 for the touch panel touched by the user is a dot spacer ( 320) can be returned to its original state immediately when the user releases the hand.

The dot spacer 320 may be formed on the first transparent electrode 310 to be in contact with the second transparent electrode 360. However, the height H of the dot spacer 320 is formed to protrude to a height H smaller than the spaced distance between the first transparent electrode 310 and the second transparent electrode 350, in particular a height of 2 to 10㎛ ( It is preferred to have H).

On the other hand, the dot spacer 320 is a protrusion having an elliptic pillar shape, the diameter of the lower end of the dot spacer 320 in contact with the first transparent electrode 310 preferably has a length of 10 to 80㎛ or less. That is, since the ellipse has a long axis and a short axis, in this case, the short axis diameter of the lower end of the dot spacer 320 is preferably 10 µm or more, and the diameter of the major axis is 80 µm or less.

4A is a conceptual diagram of an antireflection film, and FIG. 4B is a view for explaining a hard coating film and an antireflection film.

Referring to FIG. 4A, the first light L1 is incident with the incident angle θ with respect to the antireflection film B. Referring to FIG. At this time, the refractive index n _a of the air layer is smaller than the refractive index n _b of the antireflection film B. A portion of the first light L1 is reflected by the second light L2 at an angle equal to the incident angle θ, and a portion of the first light L1 is incident on the antireflection film B as the third light L3 refracted by a predetermined angle.

The third light L3 incident on the anti-reflection film B travels toward the medium C. A portion of the third light L3 is reflected by the fourth light L4, and a portion of the third light is refracted and incident on the medium C as the fifth light L5. . At this time, the refractive index n _c of the medium C is smaller than the refractive index n _b of the antireflection film B.

The fourth light L4 reflected by the interface between the anti-reflection film B and the medium C is refracted toward the air layer and emitted as the sixth light L6.

In FIG. 4A, when the light travels in a medium having a small refractive index and is reflected by a medium having a large refractive index, that is, when the light travels from the air layer to the antireflection film B and is reflected, the phase is unchanged. On the other hand, when light travels in a medium having a small refractive index and is reflected by a medium having a large refractive index, that is, when the light travels from the anti-reflection film B to the medium C and is reflected, the phase changes 180 degrees. However, the transmitted light is invariant in its phase everywhere.

Therefore, while the second light L2 shown in FIG. 4A is reflected without a phase change, the fourth light L4 is emitted by the sixth light L6 with its phase changed by 180 degrees.

In this way, the intensity of the second light L2 and the sixth light L6 traveling in a direction different from the first light L1 becomes maximum or minimum due to interference with each other. Therefore, the antireflection effect can be obtained by determining the thickness d of the antireflection film B where the light is minimized due to the interference.

The thickness d of the antireflection film B whose light is minimized due to interference can be obtained by the following equation.

Here, n denotes the refractive index n _b of the antireflection film B, and λ denotes the wavelength of light traveling through the air layer.

Equation 1 is established when the refractive index of the antireflection film B is larger or smaller than the refractive indexes of the air layer and the medium C which are in contact with the upper and lower surfaces of the antireflection film B.

When the above d value is set for 550 nm light that is most sensitive to the human eye, an anti-reflection effect can be obtained for wavelength light around 550 nm light. However, as an antireflection film of a single layer, an antireflection effect can only be expected for light having a wavelength of about 50 nm. Therefore, a plurality of antireflection films are laminated and used.

Referring to FIG. 4B, the hard coating film 380 and the anti-reflection film 390 are sequentially formed on the second polarizing plate 340 of the touch panel 300 illustrated in FIG. 2.

In general, as shown in FIG. 3A, the touch panel integrated liquid crystal display device is pressed by the user's push tens of thousands to hundreds of thousands of times until the device reaches the end of its life.

Therefore, the second polarizer 340 can be easily broken by this repetitive operation. In order to prevent this, a hard coating layer 380 made of a polyacryl material is formed on the second polarizing plate 340 to increase the hardness of the second polarizing plate 340. Thereafter, an anti-reflection film 390 is formed on the hard coating layer 380 to prevent reflection of light incident from the outside into the touch panel integrated liquid crystal display.

5A through 5E are diagrams for describing a manufacturing process of a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention.

First, referring to FIG. 5A, a lower substrate 210 in which thin film transistors (not shown) are arranged in a matrix form is provided. The pixel electrode 220 is formed by applying ITO or IZO to the surface on which the thin film transistor of the lower substrate 210 is formed by sputtering.

Subsequently, a first polarizing plate 260 for changing incident light into linearly polarized light is formed on a surface opposite to a surface on which the pixel electrode 220 of the lower substrate 210 is formed.

In the process of manufacturing the substrate illustrated in FIG. 5A, the pixel electrode 220 is first formed and then the first polarizer 260 is formed. However, the first polarizer 260 is formed on the lower substrate 210. It is apparent that the object of the present invention can be faithfully performed even when the pixel electrode 220 is formed on one surface and then formed on the surface opposite to the surface on which the first polarizing plate 260 of the lower substrate 210 is formed. .

Referring to FIG. 5B, an upper substrate 230 having a plurality of color filters (not shown) is provided. The common electrode 240 is formed on one surface of the upper substrate 230 provided with the plurality of color filters. The common electrode 240 is formed by applying ITO or IZO by the sputtering method similarly to the pixel electrode 220.

Referring to FIG. 5C, the lower substrate 210 of the liquid crystal display panel described with reference to FIG. 5A and the upper substrate 230 of the liquid crystal display panel described with reference to FIG. 5B are combined with the liquid crystal 250 therebetween. ) Is completed to complete the liquid crystal display panel 200.

Referring to FIG. 5D, as shown in FIG. 5C, the surface opposite to the surface on which the common electrode 240 of the upper substrate 230 of the liquid crystal display panel 200 is formed is completed. ITO or IZO is applied to the sputtering method to form the first transparent electrode 310. Thereafter, the dot spacer 320 is formed on the first transparent electrode 310. In this case, since the dot spacer 320 is made of a transparent material, it is not necessary to form a specific position and may be formed randomly on the first transparent electrode 310.

The manufacturing process of forming the upper substrate 330 for the touch panel will be described with reference to FIG. 5E.

First, the optical film 350 is provided. The second polarizing plate 340 is integrally provided on one surface of the optical film 350. The optical film 350 is formed of a material having an optically isotropic refractive index such as polycarbonate.

Thereafter, the second transparent electrode 360 is formed by applying ITO or IZO to a surface opposite to the surface on which the second polarizing plate 340 of the optical film 350 is provided by sputtering.

The upper panel 330 for the touch panel formed by the above manufacturing process is combined with the liquid crystal display panel 200 described with reference to FIG. 5D. In this case, an adhesive (not shown) is provided at an edge of the second transparent electrode 360 illustrated in FIG. 5E, and the first transparent electrode 310 of the liquid crystal display panel 200 illustrated in FIG. 5D is formed. The adhesive serves to bond the first transparent electrode 310 and the second transparent electrode 360 as well as to maintain the first transparent electrode 310 and the second transparent electrode 360 at regular intervals. .

As a result, the touch panel integrated liquid crystal display 100 shown in FIG. 2 is completed.

6A to 6C are views for explaining the manufacturing process of the dot spacer shown in FIG. 5D.

Referring to FIG. 6A, an upper substrate 230 of a liquid crystal display panel on which a first transparent electrode 310 is formed is provided on a surface opposite to a surface on which a plurality of color filters (not shown) are formed, and the first transparent electrode ( The organic layer 400 is coated on the 310 with a predetermined thickness.

Referring to FIG. 6B, the lower substrate 230 coated with the organic layer 400 may include a mask 500 including a light transmitting region 510 through which light is transmitted and a light blocking region 520 through which light is not transmitted. Sort on. After the mask 500 is aligned, an exposure step of supplying UV light to the mask 500 is performed.

The organic layer 400 coated on the first transparent electrode 310 is a kind of negative photoresist, and a portion that receives UV light is multiplexed.

After the exposure process, a development process is performed to remove a portion that has not received UV light. The dot spacer 320 shown in FIG. 6C is formed by removing the portion not multiplexed by the developer in the above developing step.

After the developing process, a baking process is performed to cure the dot spacer 320. At this time, by appropriately adjusting the heating temperature, the heating time, it is possible to form a dot spacer 320 having a desirable profile.

According to such a touch panel integrated liquid crystal display device, the first transparent electrode of the touch panel is formed on the upper substrate of the liquid crystal display panel, thereby eliminating unnecessary substrates to prevent loss of light passing therethrough and reducing the overall thickness of the product. In addition, manufacturing costs can be lowered.

In the above, the embodiment of the present invention has been described using the liquid crystal display as an example of an image display device. However, the present invention can be widely applied to an image display device for displaying an image as well as a liquid crystal display device.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

As described above, according to the present invention, according to the touch panel integrated image display device and the manufacturing method thereof, the first transparent electrode formed on the lower substrate of the touch panel is separately formed while integrating the touch panel with the image display device. By forming the upper surface of the image display apparatus without providing the transparent substrate, the lower substrate of the touch panel can be removed.

As a result, it is possible to prevent light loss generated when the light traveling inside the touch panel integrated liquid crystal display device passes through the lower substrate of the touch panel, and to reduce the overall thickness of the product by removing the lower substrate of the touch panel, and at the same time, the manufacturing cost. Can be lowered.

Claims (6)

A first transparent electrode formed on the upper portion of the image display device for displaying a predetermined image; A plurality of dot spacers formed on the first transparent electrode; An optical film spaced apart from the first transparent electrode by a predetermined interval; A second transparent electrode integrally formed under the optical film so as to face the first transparent electrode; And It includes a polarizing plate provided on the side opposite to the surface on which the second transparent electrode of the optical film is formed, The touch panel integrated image display apparatus detects position information by contacting the first transparent electrode and the second transparent electrode. The touch panel integrated image display apparatus of claim 1, wherein the dot spacer has an elliptic pillar shape, has a diameter of a lower end portion in contact with the first transparent electrode, and has a diameter of 10 to 80 μm and a height of 2 to 10 μm. The touch panel integrated image display apparatus of claim 1, wherein the touch panel integrated image display apparatus further comprises a hard coating layer laminated on an opposite surface of the polarizing plate on which the optical film is formed. The touch panel integrated image display apparatus of claim 3, wherein the touch panel integrated image display apparatus further comprises an anti-reflection film stacked on the hard coating layer. (a) forming a first transparent electrode on the image display device; (b) forming a dot spacer on the first transparent electrode; (c) a first step comprising a polarizing plate, a second step of forming an optical film on the polarizing plate, and a third step of forming a second transparent electrode on a surface opposite to the surface on which the optical film of the polarizing plate is formed; Forming an upper substrate for the touch panel by the step; And (d) combining the image display device formed by the step (b) and the upper substrate for the touch panel formed by the step (c) such that the first transparent electrode and the second transparent electrode face each other. A method of manufacturing a touch panel integrated image display device. The method of claim 5, wherein step (b) (b-1) applying an organic film on the first transparent electrode; (b-2) aligning the mask in which the light blocking region and the light transmitting region are formed; (b-3) exposing the organic film by passing light to the light transmitting region of the mask; And (b-4) forming a dot spacer by removing the exposed portions of the organic film.