KR20110137129A - Capacitance type touch panel and liquid crystal display device integrating the same - Google Patents

Abstract

PURPOSE: A capacitance type touch panel and a liquid crystal display device integrating the same are provided not to separately form a touch panel and to adjust the thickness thin by having a capacitance sensor which can sense the touch on a polarization plate. CONSTITUTION: Electrode patterns(120,130) are formed on both sides of a polarized plate(110). The polarization plate is laminated in orders of a first base film(111), a polarizer(112), and a second base film(113). The first and second base film is tri-acetyl cellulose, cyclo-olefin, PET(Polyethylene Terephthalate), or PMMA(Policy Methyl Metacrylte) film. The second base film is a film with an optical compensation function. An optical clear adhesive layer is laminated between a transparent and protective plate and an electrostatic capacitive type touch panel(100) and between the electrostatic capacitive type touch panel and a liquid crystal cell.

Description

Capacitive touch panel and liquid crystal display with same {CAPACITANCE TYPE TOUCH PANEL AND LIQUID CRYSTAL DISPLAY DEVICE INTEGRATING THE SAME}

The present invention relates to a capacitive touch panel capable of slimming and reducing the weight of a liquid crystal display device, increasing transmittance, improving visibility, and reducing manufacturing costs, and a liquid crystal display device having the same.

Recently, the demand for touch panel integrated liquid crystal display devices incorporating touch panel technology into liquid crystal display devices has increased dramatically in connection with various electronic devices such as personal computers, mobile phones, office devices, medical devices, or car navigation systems. Research for improvement is actively in progress.

The touch panel is mounted on the surface of the display device and converts the physical contact of the user's finger, touch pen, etc. into an electrical signal, and outputs the electrical signal. It is divided into optical (infrared) sensor method or electromagnetic induction method, and among these, the resistive film method excellent in cost and precision is most widely used.

However, compared with other methods, the resistive touch panel has a lower transmittance, a smaller effective screen area, a limited operating temperature range, and weakness over time. In consideration of this, the electrostatic capacitive method has been spotlighted in terms of transmittance and durability compared to the resistive film method.

As shown in FIG. 1, a liquid crystal display device having a capacitive touch panel is provided on a liquid crystal panel and a liquid crystal panel in which a lower polarizing plate 10 and an upper polarizing plate 20 are bonded to both surfaces of the liquid crystal cell 20. And a touch panel 40 driven in a capacitive manner therein and a transparent protective plate 50 protecting the upper portion of the touch panel 40, each of which is bonded by an optically transparent adhesive layer.

In addition, the touch panel 40 driven by the capacitive type has a structure in which the first electrode pattern 41 and the second electrode pattern 43 are formed on both surfaces of the substrate 42, as shown in FIG. 2. When a finger or a touch pen is touched while a voltage is applied to generate a uniform electric field between the first electrode pattern 41 and the second electrode pattern 42 that cross each other, a change in capacitance generated between the electrodes occurs. It is driven by the method of detecting the coordinates by detecting and calculating them.

The touch panel integrated liquid crystal display device configured as described above has a disadvantage in that the thickness of the touch panel integrated liquid crystal display device is thicker than the conventional liquid crystal display device, so that it is difficult to meet the slimmer and lighter weight required for the liquid crystal display device, and the visibility is also lowered due to the low transmittance.

The present invention is to provide a capacitive touch panel that can meet the demand of slim and light weight by reducing the thickness, improve the transmittance of the display device display window and improve the clarity and visibility, as well as reduce the manufacturing cost.

In addition, the present invention is to provide a liquid crystal display device provided with the capacitive touch panel.

1. Capacitive touch panel with electrode patterns formed on both sides of polarizer.

2. In the above 1, the polarizing plate is a capacitive touch panel that is laminated in the order of the first base film, the polarizer and the second base film.

3. In the above 2, the first base film and the second base film is a capacitive touch panel selected from the group consisting of triacetyl cellulose film, cycloolefin film, polyethylene terephthalate film and polymethyl methacrylate film, respectively .

4. The capacitive touch panel of claim 3, wherein the second base film is a film having an optical compensation function.

5. In the above 1, wherein the electrode pattern is formed of at least one selected from the group consisting of ITO, IZO, ITZO, ATO, AZO, carbon nanotubes and conductive polymer, respectively.

6. A transparent protective plate, a touch panel integrated liquid crystal display device laminated in the order of the capacitive touch panel of any one of the above 1 to 5, the liquid crystal cell and the lower polarizing plate.

7. The touch panel integrated liquid crystal display device of claim 6, wherein an optically transparent adhesive layer is further stacked between the transparent protective plate and the capacitive touch panel, and between the capacitive touch panel and the liquid crystal cell.

The capacitive touch panel according to the present invention is provided with a capacitive sensor capable of sensing a touch on the polarizing plate itself, so that when applied to a liquid crystal display device, the touch panel does not need to be formed separately and the thickness can be adjusted to be thin. It can meet the slimmer and lighter weight required more.

In addition, the transmittance is high, it is possible to improve the clarity and visibility of the liquid crystal display window.

In addition, it is possible to reduce the manufacturing cost is economic in terms of cost.

1 is a cross-sectional view of a general touch panel integrated liquid crystal display device;
2 is a cross-sectional view of a typical capacitive touch panel,
3 is a cross-sectional view of the capacitive touch panel of the present invention;
4 is a plan view illustrating one example of a first electrode pattern and a second electrode pattern of the capacitive touch panel of the present invention;
5 is a plan view illustrating another example of the first electrode pattern and the second electrode pattern of the capacitive touch panel of the present invention;
6 is a cross-sectional view of a touch panel integrated liquid crystal display device having a capacitive touch panel according to the present invention.

The present invention relates to a capacitive touch panel capable of slimming and reducing the weight of a liquid crystal display device, increasing transmittance, improving visibility, and reducing manufacturing costs, and a liquid crystal display device having the same.

Hereinafter, the present invention will be described in detail.

As illustrated in FIG. 3, the capacitive touch panel 100 of the present invention is characterized in that electrode patterns 120 and 130 are formed on both surfaces of the polarizing plate 110. That is, the polarizing plate simultaneously performs the function of the upper polarizing plate constituting the liquid crystal panel and the capacitance sensor configured to detect the change in capacitance caused by the contact of the electrode pattern formed on both sides of the polarizing plate, and calculate the coordinates to calculate the coordinates. Done.

The structure of the polarizing plate 110 is not particularly limited and may be, for example, a structure in which the first base film 111, the polarizer 112, and the second base film 113 are stacked in this order.

The polarizer 112 is a dichroic dye adsorbed on the stretched polyvinyl alcohol-based film.

The polarizer 112 is usually manufactured through a uniaxial stretching process of a polyvinyl alcohol film, a process of dyeing and adsorbing with a dichroic substance, a process of treating with an aqueous solution of boric acid, washing with water, and drying.

The thickness of the polarizer 112 may be usually 5 to 40㎛.

The first and second base films 111 and 113 are substrates for forming the first and second electrode patterns 120 and 130, and also films for protecting the polarizer 112. The first and second base films 111 and 113 are transparent, mechanical strength and thermal stability. A film excellent in moisture shielding property and isotropy can be used. Specifically, polyester-based resin, such as polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate; Cellulose resins such as diacetyl cellulose and triacetyl cellulose; Polycarbonate resin; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene resins such as polystyrene and acrylonitrile-styrene copolymers; Polyolefin resins such as polyethylene, polypropylene, cyclo-based or norbornene-structured polyolefin resins and ethylene propylene copolymers; Vinyl chloride-based resins; Polyamide resins such as nylon and aromatic polyamide; Imide resin; Polyether sulfone resin; Sulfone resins; Polyether ketone resins: sulfide polyphenylene resins; Vinyl alcohol-based resins; Vinylidene chloride-based resins; Vinyl butyral resin; Allyl resins; Polyoxymethylene resin; And films composed of thermoplastic resins such as epoxy resins, and the like, and films composed of blends of the above thermoplastic resins may also be used. Moreover, you may use the film which consists of thermosetting resins or ultraviolet curable resins, such as (meth) acrylic-type, urethane type, epoxy type, and silicone type. Among these, a triacetyl cellulose film, a cycloolefin film, a polyethylene terephthalate film, and a polymethyl methacrylate film are preferable.

The thickness of the first and second base films 111 and 113 may be generally 1 to 500 µm, preferably 1 to 300 µm, and more preferably 5 to 200 µm.

In addition, the second base film 113 may be a film having an optical compensation function such as a phase difference function.

The electrode patterns 120 and 130 formed on both surfaces of the polarizing plate are driving electrodes to which a voltage is applied, and the other serves as a sensing electrode to detect a voltage signal. For example, an electrode pattern formed on one surface of the polarizer, that is, an upper surface, may be represented by the first electrode pattern 120, and an electrode pattern formed on the other surface of the polarizer, that is, the lower surface, of the second electrode pattern 130.

The pattern shape of the first and second electrode patterns 120 and 130 is not particularly limited and may be a shape known in the art. For example, the first and second electrode patterns may be formed of a plurality of first and second electrodes that cross each other perpendicularly. More specifically, as shown in FIG. 4, the first electrode pattern 120 is formed of a plurality of first electrodes 121 parallel to the width direction (or transverse direction) of the polarizing plate, and the second electrode. The pattern 130 may include a plurality of second electrodes 131 parallel to the longitudinal direction (or machine direction) of the polarizer.

In addition, as shown in FIG. 5, the first electrode pattern 120 is formed of a plurality of first electrodes 121 connected at vertices of a triangle or a diamond shape in the width direction MD of the polarizing plate, and a second electrode pattern. The reference numeral 130 may include a plurality of second electrodes 131 having a triangle or rhombic vertex connected in the longitudinal direction MD of the polarizer, that is, the first electrode 121 and the second electrodes 131 may face each other. It is configured not to.

The first and second electrode patterns 120 and 130 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and antimony tin. Selected from the group consisting of conductive polymers such as antimony tin oxide (ATO), aluminum doped zinc oxide (Al-doped ZnO, AZO), carbon nanotubes, poly (3,4-ethylenedioxythiophene) (PEDOT) It may be formed of one or more.

In the capacitive touch panel configured as described above, the first base film 111 and the second base film 112 are bonded to both surfaces of the polarizer 112 by using an adhesive to manufacture the polarizing plate 110. The first electrode pattern 120 and the second electrode pattern 130 may be formed on both surfaces of the manufactured polarizing plate 110. In addition, the first electrode pattern 120 is formed on one surface of the first base film 111, and the second electrode pattern 130 is formed on one surface of the second base film 113. The surfaces of the first and second base films 111 and 113, on which the electrode patterns are not formed, may be respectively bonded by using an adhesive.

As the adhesive, an isocyanate-based, polyvinyl alcohol-based, gelatin-based, vinyl polymer-based latex type, water-soluble polyester-based adhesives, and the like may be used. The adhesives may be water-soluble adhesives having a solid content of 0.5 to 60% by weight.

Bonding may be performed by applying an adhesive to at least one of the bonding surfaces of the first and second substrate films or polarizers, and then bonding and drying the adhesive. The coating may use a method known in the art, for example, a casting method, a meyer bar, an air knife, gravure, a reverse roll, a kiss roll, a spray, a blade, a die coater, a casting, a spin coating, and the like, in which a roll Laminator can be used. The thickness of the adhesive layer is not particularly limited, and may be usually 0.1 to 5 μm.

For the formation of the first and second electrode patterns 120 and 130, all known methods such as sputtering, chemical vapor deposition (CVD), ion plating, and the like may be used, and the base film and the electrode may be used. The sputtering method is preferable from the viewpoint of the adhesiveness of the pattern. At this time, a mask or the like may be used.

When the electrode patterns 120 and 130 are formed, the temperature is preferably from room temperature to the glass transition temperature (Tg) of the base films 111 and 113, and more preferably from room temperature to the glass transition temperature (Tg) of the base film. A lower temperature range is preferred. When the temperature is less than room temperature, it is difficult to form the electrode pattern smoothly, and when the glass transition temperature (Tg) of the base film is exceeded, degradation of the base film may occur.

In addition, when the electrode patterns 120 and 130 are formed, a mixed gas containing a small amount of oxygen in argon, preferably a mixture containing 0.05 to 20% by volume of oxygen and more preferably 0.01 to 10% by volume of oxygen The use of gas is advantageous in that the transparency and conductivity of the electrode pattern can be improved.

The first and second electrode patterns 120 and 130 may have a thickness of 2 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less. If the thickness is greater than 2 μm, the transmittance may be lowered, resulting in poor visibility.

The capacitive touch panel of the present invention configured as described above is not a conventional touch panel, that is, a touch panel having a structure in which electrode patterns are formed on both surfaces of a transparent glass or a film, but an electrode pattern directly on a polarizing plate (upper polarizing plate) constituting a liquid crystal panel. This is formed and can function as a capacitive sensor, which itself combines the functions of a polarizing plate and a touch panel.

The driving principle of the capacitive touch panel is the same as in the conventional capacitive touch panel. For example, when a voltage is applied to the first electrode pattern 120, a change in capacitance occurs between the first electrode pattern 120 and the second electrode pattern 130 according to whether the touch is performed, and the change is applied to the second electrode. The current is output from the pattern 130 by sensing and reading the drive to detect the touch portion.

In the capacitive touch panel of the present invention, the structure other than the configuration as described above may be the same as in a conventional capacitive touch panel. For example, the control unit may apply a voltage to the first electrode pattern 120 and the second electrode pattern 130 and detect a signal in a portion of the first base film 111 and the second base film 113. And the like can be connected.

In the capacitive touch panel, the transparent protective plate 200 may be bonded by an optical clear adhesive layer (OCA) 500 on the first electrode pattern.

The transparent protective plate 200 may be a polymer film or a substrate made of a glass plate, polycarbonate, polyethylene terephthalate or polyacryl.

In addition, the optically transparent adhesive layer 500 is a layer formed from an adhesive composition comprising an adhesive resin such as an acrylic resin, a silicone resin, a styrene resin, a polyester resin, a rubber resin, or a urethane resin alone or in a mixture of two or more thereof. to be.

The liquid crystal display device of the present invention is a touch panel integrated liquid crystal display device provided with the capacitive touch panel.

As shown in FIG. 6, the liquid crystal display includes a liquid crystal panel in which a lower polarizing plate 400 is bonded to a lower surface of the liquid crystal cell 300, and is electrostatically charged by the optically transparent adhesive layer 600 on the upper surface of the liquid crystal panel. The capacitive touch panel 100 may be bonded to each other. In this case, the capacitive touch panel 100 may have a structure in which the transparent protective plate 200 is bonded by the optically transparent adhesive layer 500 on the first electrode pattern.

The liquid crystal cell 300 may have a structure in which a liquid crystal layer is interposed between two substrates.

In addition, the lower polarizing plate 400 may be a conventional adhesive polarizing plate laminated in the order of the protective film 411, the polarizer 412, the protective film 413 and the pressure-sensitive adhesive layer 414 for bonding to the liquid crystal cell. .

The liquid crystal display device configured as described above is provided with a capacitive touch panel in which an electrode pattern is directly formed on a polarizing plate to function as a capacitive sensor, thereby providing a conventional capacitive touch panel having an electrode pattern formed on a conventional substrate. There is no need to form a separate liquid crystal display device can be made thinner and lighter by reducing the thickness of the liquid crystal display device, it is possible to improve the visibility by improving the transmittance. In addition, it is possible to reduce the manufacturing cost through the omission of the configuration member and the simplification of the process.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

[Example]

Example 1

(1) Capacitive touch panel

First and second electrode patterns made of ITO were formed on one surface of each of two cycloolefin (COP) films by sputtering under a gas atmosphere in which argon and oxygen were mixed in a volume ratio of 99: 1. In this case, the shapes of the formed first and second electrode patterns are as shown in FIG. 4. The COP film having the first electrode pattern formed on one surface of the polyvinyl alcohol (PVA) polarizer and the COP film having the second electrode pattern formed on the other surface of the polarizer were bonded to each other using a polyvinyl alcohol-based adhesive and dried. Subsequently, a capacitive touch panel was manufactured by bonding a glass plate on the first electrode pattern using an adhesive sheet having an acrylic optical clear adhesive layer (OCA) interposed between two release films.

(2) liquid crystal display

A liquid crystal panel in which a lower polarizing plate composed of an adhesive layer / TAC film / PVA polarizer / TAC film was bonded to one surface of a liquid crystal cell was used. A capacitive touch panel manufactured in (1) was bonded to a liquid crystal cell of a liquid crystal panel using an adhesive sheet having an acrylic optical transparent pressure sensitive adhesive layer interposed between two release films to manufacture a liquid crystal display device.

Example 2

In the same manner as in Example 1, but in (1) a TAC film was used instead of the COP film.

Comparative Example 1

(1) Capacitive touch panel

A capacitive touch sensor was manufactured by forming first and second electrode patterns made of ITO by a sputtering method in a gas atmosphere in which argon and oxygen were mixed at a volume ratio of 99: 1 on both surfaces of the glass plate. Subsequently, a capacitive touch panel was manufactured by bonding a glass plate on the first electrode pattern using an adhesive sheet having an acrylic optical transparent adhesive layer interposed between two release films. In this case, the shapes of the formed first and second electrode patterns are as shown in FIG. 4.

(2) liquid crystal display

The liquid crystal panel in which the upper plate polarizing plate consisting of a COP film / PVA polarizer / COP film / adhesive layer and the lower plate polarizing plate consisting of an adhesive layer / TAC film / PVA polarizer / TAC film were bonded to both surfaces of the liquid crystal cell was used. The capacitive touch panel manufactured in (1) was bonded to the upper polarizing plate of the liquid crystal panel by using an adhesive sheet having an acrylic optical transparent adhesive layer interposed between two release films to manufacture a liquid crystal display device.

Comparative Example 2

It carried out similarly to the said Comparative Example 1, but used the upper plate polarizing plate comprised from TAC film / PVA polarizer / TAC film / adhesive layer in (2).

Test Example

The transmittance of the capacitive touch panel manufactured in Examples and Comparative Examples was measured using an ultraviolet visible light spectrometer (V-7100, JASCO), and the results are shown in Table 1 below.

division Capacitive Touch Panel Thickness (㎛) Transmittance
(%) Glass plate OCA Capacitive Touch Sensor OCA 1st
electrode
pattern First description
film Polarizer Second
electrode
pattern Second
materials
film Total thickness Example 1 700 25 - - One 52 30 52 One 861 41.4 Example 2 700 25 - - One 80 30 80 One 917 41.2 Comparative Example 1 700 25 700 25 - 52 30 52 - 1584 40.4 Comparative Example 2 700 25 700 25 - 80 30 80 - 1640 40.2

As shown in the above table, according to the present invention, the electrode patterns are formed on both sides of the polarizing plate, and thus, the touch panels of Examples 1 and 2 having the functions of the upper polarizing plate as well as the touch panel are comparative examples of the upper polarizing plate laminated on a conventional touch panel. Compared with 2, the thickness was found to be significantly thinner and the transmittance was also high. That is, it is possible to slim down and lighten the liquid crystal display device applying the same, and also improve visibility.

10: lower polarizing plate 20: liquid crystal cell
30: upper polarizing plate
40: capacitive touch panel
41: first electrode pattern 42: substrate
43: second electrode pattern 50: transparent protective plate
100: capacitive touch panel 110: polarizing plate
111: first substrate film 112: polarizer
113: second substrate film 120: the first electrode pattern
121: first electrode 130: second electrode pattern
131: second electrode 200: transparent protective plate
300: liquid crystal cell 400: lower plate polarizing plate
411, 413: Protective film 412: Polarizer
414: pressure-sensitive adhesive layer 500, 600: optical transparent pressure-sensitive adhesive layer

Claims (7)

A capacitive touch panel in which electrode patterns are formed on both sides of a polarizing plate.
The method of claim 1, wherein the polarizing plate is a capacitive touch panel that is laminated in the order of the first substrate film, the polarizer and the second substrate film.
The capacitive touch panel according to claim 2, wherein the first base film and the second base film are each selected from the group consisting of a triacetyl cellulose film, a cycloolefin film, a polyethylene terephthalate film, and a polymethyl methacrylate film.
The capacitive touch panel of claim 3, wherein the second substrate film is a film having an optical compensation function.
The capacitive touch panel of claim 1, wherein the electrode pattern is formed of at least one selected from the group consisting of ITO, IZO, ITZO, ATO, AZO, carbon nanotubes, and conductive polymers.
Touch panel integrated liquid crystal display device laminated in the order of the transparent protective plate, the capacitive touch panel of any one of claims 1 to 5, the liquid crystal cell and the lower polarizing plate.
The liquid crystal display device of claim 6, wherein an optically transparent adhesive layer is further stacked between the transparent protective plate and the capacitive touch panel, and between the capacitive touch panel and the liquid crystal cell.

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