KR20080049305A - Liquid display device - Google Patents

Abstract

An LCD(Liquid Crystal Display) is provided to detect whether a finger of a user or a touch pen is contacted with a screen and detect contact location information exactly by forming a lower ITO(Indium Tin Oxide) ohmic layer on a spacer for contact, thereby improving reliability of a detector. A display unit includes lower and upper substrates(110,210). A spacer for contact(300) is formed in an upper part of the upper substrate and has a protruded shape. A lower ohmic layer(305) is formed so as to surround the spacer for contact in an upper part of the spacer for contact. An upper ohmic layer(325) is formed in an upper side of the lower ohnmic layer. A film(320) is formed in an upper part of the upper ohmic layer. By a spacer for support(350) formed on the lower ohmic layer, the lower ohmic layer and the upper ohmic layer are spaced at a predetermined interval and the upper ohmic layer is supported. The upper and lower ohmic layers are made of ITO.

Description

Liquid crystal display {LIQUID DISPLAY DEVICE}

1 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 shows the form of a contact spacer and a support spacer here

1 is a cross-sectional view of a liquid crystal display according to another exemplary embodiment of the present invention.

<Description of Drawing>

110: lower substrate 191: pixel electrode

210: upper substrate 250: common electrode

230: color filter 3: liquid crystal layer

305: lower ITO resistive film 325: upper ITO resistive film

350: support spacer 370: seal member

       300: spacer for contact 320: film

The present invention relates to a liquid crystal display device.

In recent years, with the reduction in weight and thickness of personal computers and televisions, display devices are also required to be lighter and thinner, and cathode ray tubes (CRTs) are being replaced by flat panel displays.

Such flat panel displays include liquid crystal displays (LCDs), field emission displays (FEDs), organic light emitting displays (OLEDs), plasma display panels (PDPs). ).

Typical liquid crystal displays (LCDs) among display devices include two display panels provided with pixel electrodes and a common electrode, and a liquid crystal layer having dielectric anisotropy interposed therebetween. The pixel electrodes are arranged in a matrix and connected to switching elements such as thin film transistors (TFTs) to receive data voltages one by one in sequence. The common electrode is formed over the entire surface of the display panel and receives a common voltage. The pixel electrode, the common electrode, and the liquid crystal layer therebetween form a liquid crystal capacitor, and the liquid crystal capacitor becomes a basic unit that forms a pixel together with a switching element connected thereto.

A touch screen panel is a device that touches a finger or a touch pen (stylus) on the screen to write and draw letters or pictures, or execute icons to perform a desired command on a machine such as a computer. . A liquid crystal display with a touch screen panel may find out whether a user's finger or a touch pen touches the screen and contact position information. However, such a liquid crystal display has problems such as a cost increase due to a touch screen panel, a decrease in yield due to a process of attaching the touch screen panel to a liquid crystal panel, a decrease in luminance of the liquid crystal panel, and an increase in product thickness.

An object of the present invention is to provide a liquid crystal display device in which a touch screen function is integrated.

In order to solve this problem, a liquid crystal display according to an exemplary embodiment of the present invention includes a display unit including a lower substrate and an upper substrate, a contact spacer formed on an upper portion of the upper substrate, and having a protrusion shape, and an upper portion of the contact spacer. A lower resistive film formed to surround the contact spacer, an upper resistive film formed on the lower resistive film, and a film formed on the upper resistive film, wherein the lower resistive film is formed on the lower resistive film. The lower resistive film and the upper resistive film are spaced by a predetermined interval by the supporting spacer, and the upper resistive film is supported.

The upper resistive film and the lower resistive film may be made of ITO.

It may further include an upper polarizing plate attached to the upper surface of the film.

The lower polarizer may be further attached to a lower surface of the lower substrate.

The contact spacer may have a diameter of about 0.1 μm to about 500 μm.

The support spacer may have a diameter of about 0.1 μm to about 500 μm.

The contact spacer may be a transparent insulator.

The support spacer may be a transparent insulator.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

First, a liquid crystal display according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

The liquid crystal display according to the exemplary embodiment of the present invention includes a display unit and a detector.

The display unit includes the thin film transistor 190, the pixel electrode 191, the common electrode 250, and the color filter 230 between the upper substrate 210, the lower substrate 110, and the upper substrate 210 and the lower substrate 110. ) And the liquid crystal layer 3 and the like. The lower polarizer 12 is attached to the lower side of the lower substrate 110 using an adhesive (not shown).

Meanwhile, the sensing unit is positioned on the contact spacer 300, the lower ITO resistive layer 305, the upper ITO resistive layer 325, and the upper ITO resistive layer 325 formed on the upper side of the upper substrate 210. A support spacer 350 and a seal member 370 positioned between the film 320, the lower ITO resistive film 305, and the upper ITO resistive film 325, and the upper ITO resistive film 325. The upper polarizer 22 is attached to the upper side of the adhesive using an adhesive (not shown).

Looking at the structure of the liquid crystal display according to the embodiment of Figure 1 in detail as follows.

First, FIG. 1 briefly illustrates only common components of the display unit.

The display unit may be formed in various embodiments, and the structure of the general display unit is as follows.

A plurality of gate lines (not shown) and a plurality of storage electrode lines (not shown) are formed on the lower substrate 110 made of transparent glass or plastic.

The gate line transmits a gate signal and mainly extends in the horizontal direction. Each gate line includes a wide end portion for connecting a plurality of gate electrodes (not shown) with another layer or an external driving circuit.

The storage electrode line receives a predetermined voltage and includes a storage electrode (not shown). A gate insulating film (not shown) made of silicon nitride (SiNx) or silicon oxide (SiOx) is formed on the gate line and the storage electrode line.

A semiconductor (not shown) made of hydrogenated amorphous silicon, polycrystalline silicon, or the like is formed on the gate insulating film. An ohmic contact (not shown) is formed on the semiconductor. The ohmic contact member may be made of a material such as n + hydrogenated amorphous silicon in which n-type impurities such as phosphorus (P) are heavily doped, or may be made of silicide. A plurality of data lines (not shown) and a plurality of drain electrodes (not shown) are formed on the ohmic contact member and the gate insulating film.

The data line transmits a data signal and mainly extends in the vertical direction to intersect with the gate line and intersect with the storage electrode line. Each data line includes a plurality of source electrodes (not shown) extending toward the gate electrode and end portions (not shown) having a large area for connection with another layer or an external driving circuit.

The drain electrode is separated from the data line and faces the source electrode with respect to the gate electrode.

One gate electrode, one source electrode, and one drain electrode form one thin film transistor 190 together with a semiconductor, and a channel of the thin film transistor is formed between the source electrode and the drain electrode.

The ohmic contact is present only between the semiconductor underneath and the data line and drain electrode thereon and lowers the contact resistance therebetween.

A protective film (not shown) is formed on the data line, the drain electrode, and the exposed semiconductor portion. The protective film is made of an inorganic insulator such as silicon nitride or silicon oxide, an organic insulator, or a low dielectric insulator.

A plurality of pixel electrodes 191 and a plurality of contact assistants (not shown) are formed on the passivation layer. These may be made of a transparent conductive material such as ITO or IZO or a reflective metal such as aluminum, silver or an alloy thereof.

The pixel electrode 191 is physically and electrically connected to the drain electrode through the contact hole and receives a data voltage from the drain electrode. The pixel electrode 191 to which the data voltage is applied generates an electric field together with the common electrode 250 of the upper substrate 210 to which the common voltage is applied, thereby creating a liquid crystal layer 3 between the two electrodes. Determines the direction of the liquid crystal molecules.

The pixel electrode 191 overlaps the storage electrode line including the storage electrode. The capacitor formed by the pixel electrode 191 and the drain electrode electrically connected thereto is called a storage capacitor, and the storage capacitor enhances the voltage holding capability of the liquid crystal capacitor.

The contact auxiliary members are connected to the ends of the gate lines and the ends of the data lines through contact holes, respectively.

Meanwhile, the upper substrate 210 is made of glass, plastic, or the like, and a light blocking member (not shown) is formed on the insulating substrate 210. The light blocking member includes a linear portion corresponding to the gate line and the data line and a planar portion corresponding to the thin film transistor, and prevents light leakage between the pixel electrodes 191.

A plurality of color filters 230 is also formed on the upper substrate 210. The color filter 230 is mostly present in an area surrounded by the light blocking member, and may extend in the vertical direction along the column of the pixel electrodes 191. Each color filter 230 may display one of primary colors such as three primary colors of red, green, and blue.

An overcoat (not shown) is formed on the color filter 230 and the light blocking member. The overcoat may be made of an organic insulator, which prevents the color filter 230 from being exposed and provides a flat surface.

The common electrode 250 is formed on the overcoat. The common electrode 250 is made of a transparent conductor such as ITO or IZO.

An alignment layer (not shown) is coated on the inner surfaces of the pixel electrode 191 and the common electrode 250, which may be a vertical alignment layer or a horizontal alignment layer.

The liquid crystal layer 3 positioned between the pixel electrode 191 and the common electrode 250 has dielectric anisotropy. In the absence of an electric field, the liquid crystal molecules of the liquid crystal layer 3 are in a vertical alignment (VA) mode in which their major axes are oriented perpendicular to the surfaces of the two substrates 110 and 210 or the two substrates 110 and 210. It may have a twisted nematic (TN) mode that is oriented to be horizontal to the surface of.

When a common voltage is applied to the common electrode 250 and a data voltage is applied to the pixel electrode 191, an electric field (electric field) is generated therebetween. Liquid crystal molecules change their orientation in response to an electric field.

Since the display unit may be formed in various embodiments, the common electrode 250 and the pixel electrode 191 may be formed on the same substrate as described above.

The lower polarizing plate 12 is attached to the lower side of the display unit using an adhesive. The lower polarizer 12 filters the part or all of the light passing through the liquid crystal layer 3 together with the upper polarizer 22.

The upper part of the upper substrate 210 is formed with a sensing unit for determining the position at the time of contact from the outside.

The structure of the detector is as follows.

The contact spacer 300 is disposed in the form of a protrusion on the upper surface of the upper substrate 210. Here, the contact spacer 300 may be formed of a transparent insulator, and may be formed in a desired shape by applying an insulator and then patterning the insulator. A lower ITO resistive film 305 is formed on the contact spacer 300 and surrounds the contact spacer 300.

An upper ITO resistive film 325 is formed on the lower side of the lower ITO resistive film 305, and an upper polarizing plate 22 is attached to the film 320 by an adhesive (not shown). have. The film 320 is formed of a soft film.

The support spacer 350 and the seal member 370 between the upper ITO resistive film 325 and the lower ITO resistive film 305 so that the upper ITO resistive film 325 is kept at a predetermined distance from the lower ITO resistive film 305. ) Is formed. The seal member 370 is formed to support the outer shells of the upper ITO resistive film 325 and the lower ITO resistive film 305, and the support spacer 350 is formed at the center of the upper ITO resistive film 325. The lower ITO resistive film 305 is spaced apart and supports the upper ITO resistive film. The support spacer 350 is formed where the contact spacer 300 is not formed, and the support spacer 350 is formed of a transparent insulator.

2 is a view showing the form of the contact spacer and the support spacer here.

As shown in Figure 2, it can be formed in various forms, such as trapezoid, cylinder, square. In addition, the diameter of the contact spacer and the support spacer is preferably about 0.1 to 500μm, it is preferable to use a transparent material.

The upper ITO resistive film 325 and the lower ITO resistive film 305 contact each other by external magnetic poles, and operate in a manner of determining the contact position by measuring resistance. After contact, the upper ITO resistive film 325 and the lower ITO resistive film 305 are spaced apart by the support spacer 350.

As described above, the lower ITO resistive layer may be formed on the upper substrate 210 of the display unit instead of a separate substrate, thereby reducing the thickness of the display device and reducing the cost. In addition, the lower ITO resistive film 305 is formed to surround the contact spacer 300 to accurately detect whether the user's finger or touch pen touches the screen and the contact location information, thereby increasing reliability of the sensing unit. . In addition, the support spacer 350 may be formed to support the upper ITO resistive film 325, thereby preventing the Newton ring phenomenon frequently occurring in the liquid crystal display device having a touch screen function.

3 is a cross-sectional view of a liquid crystal display according to another exemplary embodiment of the present invention.

As shown in FIG. 3, the liquid crystal display according to the exemplary embodiment of the present invention includes a display unit and a sensing unit.

The display unit includes the thin film transistor 190, the pixel electrode 191, the common electrode 250, and the color filter 230 between the upper substrate 210, the lower substrate 110, and the upper substrate 210 and the lower substrate 110. ) And the liquid crystal layer 3 and the like. The lower polarizing plate 12 is attached to the lower side of the lower substrate 110 by using an adhesive (not shown).

Meanwhile, the sensing unit is positioned on the contact spacer 300, the lower ITO resistive layer 305, the upper ITO resistive layer 325, and the upper ITO resistive layer 325 formed on the upper side of the upper substrate 210. An upper ITO resistive film 325 comprising an optical film 320, a support spacer 350 positioned between the lower ITO resistive film 305 and the upper ITO resistive film 325, and a seal member 370. The upper polarizing plate 22 is attached to the upper side using the adhesive (not shown).

As described above, the liquid crystal display according to the exemplary embodiment of FIG. 3 is almost similar to the liquid crystal display according to the exemplary embodiment of FIG. 1, but the contact spacer 305, the support spacer 350, and the lower ITO resistive layer 305 of the sensing unit. ), There is a difference in the method of forming.

In other words, in order to form the contact spacer 300 and the support spacer 350, an insulating material is coated and then patterned to simultaneously form the contact spacer 305 and the support spacer 350 having a desired shape. The contact spacer 300 is smaller in size than the support spacer 350. Thereafter, the lower ITO resistive film 305 is coated to surround the contact spacer 305 and the support spacer 350. Thereafter, the lower ITO resistive film 305 surrounding the support spacer 350 is removed.

Therefore, the lower ITO resistive film 305 is formed around the contact spacer 300, but the lower ITO resistive film 305 is not formed on the support spacer 350.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, the liquid crystal display device in which the touch screen function is integrated according to the present invention forms a lower ITO resistive film to surround the contact spacers on the contact spacers having the shape of the protrusions, so that a user's finger or a touch pen is screened. It is possible to accurately detect whether the contact and the contact location information. Therefore, the reliability of the sensing unit can be improved. In addition, by forming a support spacer to support the upper ITO resistive film, it is possible to prevent the Newton ring phenomenon that occurs frequently in the liquid crystal display device with integrated touch screen function.

Claims (8)

A display unit including a lower substrate and an upper substrate, A contact spacer formed on the upper substrate and having a protruding shape, A lower resistance layer formed to surround the contact spacers on the contact spacers; An upper resistive film formed on the lower resistive film, and It includes a film formed on the upper resistive film, And a lower space between the lower resistive film and the upper resistive film by a support spacer formed on the lower resistive film and supporting the upper resistive film. In claim 1, The upper resistive film and the lower resistive film are made of ITO. In claim 1, And an upper polarizing plate attached to an upper surface of the film. In claim 3, And a lower polarizer attached to a lower surface of the lower substrate. In claim 1, The contact spacer has a diameter of 0.1 to 500μm liquid crystal display device. In claim 1, The support spacer has a diameter of 0.1 to 500μm liquid crystal display device. In claim 1, And the contact spacer is a transparent insulator. In claim 1, And the support spacer is a transparent insulator.

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