KR101166084B1 - Liquid crystal touch screen panel - Google Patents

Abstract

The liquid crystal touch screen panel includes a first substrate, a second substrate disposed to face the first substrate, an electrode pattern portion disposed on the second substrate, and liquid crystal molecules interposed between the electrode pattern portion and the first substrate. The liquid crystal layer includes a liquid crystal layer, and senses an external stimulus applied on the first substrate based on a change in the amount of charge generated by the external stimulus applied to the first substrate.

Description

LCD touch screen panel {LIQUID CRYSTAL TOUCH SCREEN PANEL}

The present invention relates to a liquid crystal touch screen panel.

Conventionally, the touch screen has a basic configuration of a liquid crystal or organic EL display panel displaying image information, a touch panel attached or embedded in the display panel, a signal input / output integrated circuit, a device driver, and application software. Currently, a touch method commonly used in a touch screen of a mobile device is a resistive method and a capacitive method.

In the resistive film method, when a user presses a screen, the input is sensed by detecting a change in current and resistance generated when the transparent conductive films are in contact with each other. In this case, the touch screen is a layer in which several layers are stacked on the display panel, and a film made of a scratch-resistant material is formed on the outermost side of the contact area of the hand or the stylus pen, and a film that softens the impact and Overlapping transparent conductive film to sense touch.

However, the resistive film method has a problem in that multi-touch is impossible in terms of function, and the screen clarity is lowered by stacking multiple layers on the display panel.

The capacitance method is a method of determining an input by using a phenomenon in which the intrinsic capacitance of the touch screen is changed by an external stimulus. In general, static electricity in the body causes a change in the capacitance. In other words, the current is applied to the touch screen substrate by coating an electrically conductive material or compound. At this time, when the finger touches the screen, electrons flowing on the tentacle position are attracted to the contact point, and the capacitance of the touch screen at the corresponding point is changed, and a circuit installed at the periphery of the touch screen senses the input and determines the input. .

However, the capacitive method is impossible to input when using a non-conductor rather than a material that induces electrons like a finger. Therefore, input cannot be made using the stylus pen used in the above-described resistive film method, and a finger or a capacitive stylus pen must be used.

Accordingly, there is a need for a touch screen panel capable of single touch and multi touch using a hand, a stylus pen, and other objects while accommodating the advantages of the resistive type and the capacitive type.

According to an embodiment of the present invention, by sensing the external stimulus applied to the substrate based on the amount of charge that changes according to the external stimulus such as pressure applied to the substrate, various types of touch inputs are possible, and the liquid crystal by the external stimulus such as pressure It is an object of the present invention to provide a liquid crystal touch screen panel that can realize multi-gradation according to touch intensity by using an effect of changing capacitance of a cell.

As a technical means for achieving the above-described technical problem, the liquid crystal touch screen panel according to an embodiment of the present invention is the first substrate, the second substrate disposed to face the first substrate, the electrode disposed on the second substrate A liquid crystal layer comprising liquid crystal molecules interposed between the pattern portion and the electrode pattern portion and the first substrate, wherein the external magnetic pole is applied on the first substrate based on a change in the amount of charge generated by the external magnetic pole applied to the first substrate; Detect.

In addition, the liquid crystal touch screen panel according to another embodiment of the present invention is disposed on the first substrate, the second substrate disposed to face the first substrate, the first electrode disposed below the first substrate, and the upper portion of the second substrate. A second electrode and a liquid crystal layer comprising liquid crystal molecules interposed between the first electrode and the second electrode, the liquid crystal layer being applied on the first substrate based on a change in the charge amount caused by an external stimulus applied to the first substrate. Detect external stimuli.

According to any one of the problem solving means of the present invention described above, by sensing the external stimulus applied to the substrate based on the amount of charge that changes according to the external stimulus, such as the pressure applied to the substrate, to enable various types of touch input, Multi-gradation can be realized according to the touch intensity by using the effect of changing the capacitance of the liquid crystal cell by an external stimulus.

In addition, according to any one of the problem solving means of the present invention described above, unlike the conventional capacitive method that only changes the capacitance in accordance with the external stimulus, by inducing the generation of the current by the external stimulus, by detecting the changed current, Since the capacitive structure enables sensing of external stimulus like a resistive film, not only multi-sensing but also sensing by various touch sensors is possible.

1 and 2 illustrate an arrangement of liquid crystal molecules when an external stimulus is applied to a liquid crystal touch screen panel according to an exemplary embodiment of the present invention.
FIG. 3 is a plan view of a matrix array configuration for detecting a signal at a position where an external magnetic pole is applied in a liquid crystal touch screen panel according to an embodiment of the present invention in which first and second electrodes are cross-arranged. to be.
4 to 6 illustrate various configurations of the liquid crystal touch screen panel according to an embodiment of the present invention.
7 illustrates a configuration of a liquid crystal touch screen panel according to another embodiment of the present invention.
8 and 9 illustrate a principle of operation of a liquid crystal touch screen panel to which a liquid crystal or liquid crystal polymer having a banana-type molecular structure or a wedge-shaped molecular structure according to another embodiment of the present invention is applied.
FIG. 10 illustrates another operation principle of a liquid crystal touch screen panel to which a banana type liquid crystal or a liquid crystal polymer is applied according to an embodiment of the present invention.
11 illustrates a liquid crystal of various types of polarization structures according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

1 and 2 illustrate an arrangement of liquid crystal molecules when an external stimulus is applied to a liquid crystal touch screen panel according to an exemplary embodiment of the present invention.

1 and 2, a liquid crystal touch screen panel 100 (LCTSP) including a liquid crystal or a liquid crystal polymer having an organic material, such as a banana-like molecular structure (A ') or a wedge-shaped molecular structure (B'). In the Liquid Crystal Touch Screen Panel), when an external stimulus such as pressure is applied to the substrate, an asymmetric liquid crystal, such as a banana-type or wedge-type liquid crystal, which has a permanent dipole even at a small amount, sprays in response to a change in the fine curvature of the surface substrate. (splay) or bend (bend) structure easily changes its alignment state, in which the net electrical in the direction of the direction of the liquid crystal of the liquid crystal or the direction opposite to the direction of the liquid crystal (z-axis) as defined in Equation 1 below. Charges accumulate as dipoles are generated, leading to macroscopic polarization. This effect is called the piezoelectric effect and the flexoelectric effect.

As a dipole moment generated in proportion to the amount of force (pressure) applied to the substrate, polarization may be defined as in Equation 1 below.

는 액정의 기울기 각도,

는 변위 x에 따른 액정 분자들의 기울기 변화를 나타낸다.In Equation 1, e1 is the spray modulus of the liquid crystal, e3 is the bend modulus of the liquid crystal, n is a liquid crystal director indicating the direction of the liquid crystal molecules,

The tilt angle of the liquid crystal,

Denotes a change in tilt of liquid crystal molecules according to the displacement x.

FIG. 3 is a plan view of a matrix array configuration for detecting a signal at a position at which an external stimulus is applied in a liquid crystal touch screen panel according to an embodiment of the present invention in which first and second electrodes are cross-arranged. to be. In this case, the arrangement of the electrodes may be modified in various embodiments in various forms.

Hereinafter, the configuration of the liquid crystal touch screen panel to which the above-described piezoelectric effect and the substation effect and the electrodes of the cross-arranged form of FIG. 3 are applied will be described in more detail with reference to FIGS. 4 and 7.

4 to 6 illustrate various configurations of the liquid crystal touch screen panel according to an embodiment of the present invention.

As shown in FIGS. 4A and 4B, the liquid crystal touch screen panel 100 according to an exemplary embodiment of the present invention is disposed to face the first substrate 102 and the first substrate 102. The second substrate 103, the first electrode 105 disposed below the first substrate 102, the second electrode 106 disposed above the second substrate 103, and the first electrode 105; And a liquid crystal layer 104 made of liquid crystal molecules interposed between the second electrodes 106.

Here, the liquid crystal layer 104 includes a liquid crystal or a liquid crystal polymer having a banana-like molecular structure (A ') or a wedge-shaped molecular structure (B'), wherein the liquid crystal polymer is a main chain type, a side chain type, a cross-link type, and a dendrimer type. It may include any one liquid crystal polymer. The liquid crystal layer 104 may include a liquid crystal having optical anisotropy birefringence and having one or more phase structures of nematic, smectic, and cholesteric.

In addition, as shown in (a) and (b) of FIG. 5, the liquid crystal touch screen panel 100 according to an exemplary embodiment of the present invention may include the lower part of the first electrode 105 and the second electrode 106. It may further include an insulating layer 107 disposed above each. This may adjust the size of the total capacitance value for the purpose of securing a fixed capacitance value does not change by external stimulation of the total capacitance value of the liquid crystal touch screen panel 100. In this case, the disposed insulating layer may serve as an alignment layer, and may form a separate alignment layer, which is for the purpose of making the initial alignment state of the banana- or wedge-shaped liquid crystal molecules uniform. The more the polarization effect induced by external force becomes stronger.

In addition, as illustrated in FIGS. 6A and 6B, the liquid crystal touch screen panel 100 according to the exemplary embodiment of the present invention may have a second substrate 103 and an upper portion of the second substrate 103. It may further include a third electrode 108 and the insulating layer 107 disposed between the second electrode 106 disposed in the. More specifically, the third electrode 108 is disposed above the second substrate 103, and the insulating layer 107 is disposed above the third electrode 108. This is to achieve the effect of two separate capacitive elements connected in series for the purpose of independently securing a fixed capacitance value that does not change by external stimulation of the total capacitance value of the liquid crystal touch screen panel 100, The capacitance value can be adjusted.

5 to 6, the insulating layer 107 has a constant capacitance and there is no change in permittivity due to external stimulation, thereby obtaining a fixed capacitance value. In addition, the third electrode 108 is an auxiliary electrode, which helps to detect an external stimulus more effectively by increasing energy transfer efficiency.

7 illustrates a configuration of a liquid crystal touch screen panel according to another embodiment of the present invention.

As illustrated in FIG. 7, the liquid crystal touch screen panel 100 according to another exemplary embodiment of the present invention may include a first substrate 102, a second substrate 103 disposed opposite to the first substrate 102, and a first substrate 102. 2, an electrode pattern part 101 disposed on the substrate 103, and a liquid crystal layer 104 made of liquid crystal molecules interposed between the electrode pattern part 101 and the first substrate 102. Here, the electrode pattern part 101 may include a first electrode 105, a second electrode 106, and an insulating layer 107 disposed between the first electrode 105 and the second electrode 106. have. Here, the insulating layer 107 has a constant capacitance, there is no change in the dielectric constant according to the external stimulus can obtain a fixed capacitance value.

The liquid crystal layer 104 of FIG. 7 includes a liquid crystal or a liquid crystal polymer having a banana-like molecular structure (A ') or a wedge-shaped molecular structure (B'), wherein the liquid crystal polymer has a main chain type, a side chain type, a cross-link type, and a dendrimer type. It may include any one of the liquid crystal polymer. In addition, the liquid crystal layer 104 may include a liquid crystal having optical anisotropy birefringence and having one or more phase structures of nematec, smectic, and cholesteric.

8 and 9 illustrate a principle of operation of a liquid crystal touch screen panel to which a liquid crystal or liquid crystal polymer having a banana-type molecular structure or a wedge-shaped molecular structure according to another embodiment of the present invention is applied.

As shown in FIGS. 8 and 9, in the structure of a liquid crystal touch screen panel 100 including a liquid crystal or a liquid crystal polymer having a banana-like molecular structure A 'or a wedge-shaped molecular structure B', for example, When pressure is applied to the substrate 102 as an external magnetic pole, the liquid crystal layer 104 generates an elastic deformation in the form of a spray or bend by the pressure applied to the first substrate 102. The elastic deformation in the form of a spray or bend has been described above with reference to FIGS. 1 and 2.

Then, the position on the first substrate 102 to which the pressure is applied can be sensed based on the change ΔC of the capacitance of the electrode pattern portion 101 changed by the elastic deformation. In this case, as shown in FIG. 9, in the case of the liquid crystal touch screen panel 100 including a liquid crystal or a liquid crystal polymer having a wedge molecular structure (B ′), when a pressure is applied to the first substrate 102, the wedge shape The liquid crystal molecules may be aligned in a certain shape and modified.

More specifically, the insulating layer 107 formed between the first electrode 105 and the second electrode 106 has a constant capacitance, and the capacitance changes as the amount of charge changes with pressure. In addition, when the first electrode 105 and the second electrode 106 are subjected to an external pressure applied to a specific site, and a charge is generated by the dipole induction, the capacitance of the insulating layer 107 changes according to the change in the amount of charge. To detect the position of the part where the pressure is applied.

At this time, since the amount of charge induced is proportional to the pressure, multi-gradation can be realized according to the strength of the pressure. In addition, capacitive multi-touch is possible, and a piezoelectric effect and a substation effect are generated by the action of pressure, so that the touch sensor can be operated with a stylus pen or other objects.

In addition, since the liquid crystal touch screen panel 100 of the present invention uses polarization through elastic deformation of liquid crystal molecules, the liquid crystal touch screen panel 100 differs from the conventional method using a piezoelectric effect in which electric polarization is generated by an external pressure. There is. In addition, unlike the conventional capacitive method in which only the capacitance changes depending on external pressure, the current can be induced internally and the changed current can be detected.

In addition, the liquid crystal touch screen panel 100 of the present invention may improve characteristics such as a touch screen panel (TSP) by using a piezoelectric effect and a substation effect by an external physical force, which generates an electric field and uses the same. This is different from the conventional liquid crystal device that improved the response speed of liquid crystal displays (LCDs).

FIG. 10 illustrates an operation principle of a liquid crystal touch screen panel to which a banana-type liquid crystal or a liquid crystal polymer is applied according to an embodiment of the present invention.

As shown in FIG. 10, in the structure of a liquid crystal touch screen panel 100 including a liquid crystal or a liquid crystal polymer having a banana-type molecular structure A ′, for example, when pressure is applied to the first substrate 102 as an external stimulus The external stimulus applied to the first substrate 102 may be sensed based on the change in the amount of charge generated by the external stimulus applied to the first substrate 102. Here, an alignment film (not shown) is provided between the first substrate 102 and the liquid crystal layer 104 or between the second substrate 103 and the liquid crystal layer 104 for uniform alignment of the banana type liquid crystal and wedge type liquid crystal molecules of the present embodiment. May be arranged.

More specifically, in the case where the electrical alignment is formed due to the alignment of the molecules due to the alignment, when a pressure is applied to the first substrate 102, some of the liquid crystal molecules of the liquid crystal layer 104 disposed under the pressured region The reverse direction (C ') changes the direction of the spontaneous polarization (spontaneous polarization).

(

는 z축 단위 벡터임)만큼의 전하가 축적되어 있다가 외압에 의해 액정층(104)의 액정 분자 중 일부의 방향이 역전되면, 전하량이 두 배가 된다.Here, the spontaneous polarization P is a vector amount, and between the first electrode 105 and the second electrode 106 at both ends of the insulating layer (liquid crystal layer 104) before the external pressure is applied.

(

Is a z-axis unit vector), and when the direction of some of the liquid crystal molecules of the liquid crystal layer 104 is reversed by external pressure, the amount of charge is doubled.

)이 유도된다. 따라서, 제 1 전극(105)과 제 2 전극(106)간에 전위차가 변하게 되며, 해당 전압 변화를 감지함으로써 터치스크린 패널 상에 가해진 힘의 위치 정보를 파악할 수 있다.That is, when an external force is applied to a specific region and the alignment state of the liquid crystal molecules is reversed by 180 degrees (C '), and the spontaneous polarization direction is changed by 2P, the amount of charge corresponding to twice that region of the second electrode 106 is changed. (ΔC) (i.e.

) Is derived. Accordingly, the potential difference is changed between the first electrode 105 and the second electrode 106, and the positional information of the force applied to the touch screen panel can be grasped by sensing the corresponding voltage change.

At this time, the dipoles of the liquid crystal of the banana-type molecular structure (A ') are rotated by more angles than the initial force as the magnitude of the externally applied force increases, and thus the macroscopic polarization change also increases, so that the gray level of the touch intensity can be detected. It becomes possible. The operating principle of the liquid crystal touch screen panel 100 according to the exemplary embodiment of FIG. 10 may be applied to the structure of the liquid crystal touch screen panel 100 of FIGS. 4 to 7 described above.

11 illustrates a liquid crystal of various types of polarization structures according to an embodiment of the present invention.

As shown in FIG. 11, the liquid crystals of the ferroelectric or antiferroelectric liquid crystal layer 104 may have inclined chiral phases in the same direction or opposite directions, or may have inclined racemate phases. Can be. For example, it is possible to have a liquid crystal of all Bn (n = 1, 2, 3, ...) which can be classified as SmC _x P _y (x = A or S, y = A or F). Here, B represents the phase of the liquid crystal having a banana-type molecular structure.

More specifically, FIG. 11A shows a semiferroelectric liquid crystal form SmC _A P _A having a racemic phase inclined in opposite directions, and FIG. 11B shows a mirror in the same direction. The ferroelectric liquid crystal form (SmC _S P _F ) with a photographic chiral phase is shown.

FIG. 11C shows a semiferroelectric liquid crystal form SmC _S P _A having a racemic phase inclined in the same direction, and FIG. 11D shows a chiral phase inclined in opposite directions. The ferroelectric liquid crystal form (SmC _A P _F ) having is shown.

On the other hand, in the above-described structure of the liquid crystal touch screen panel 100, a material capable of polarization may be made of a polymer film through a polymerization and synthesis process, thereby lowering the material cost.

In addition, the above description of the present invention is for illustrative purposes, and those skilled in the art to which the present invention pertains may understand that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. Could be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

101: electrode pattern portion
102: first substrate
103: second substrate
104: liquid crystal layer
105: first electrode
106: second electrode
107: insulation layer
108: third electrode

Claims (13)

In the liquid crystal touch screen panel,
First substrate,
A second substrate disposed opposite the first substrate,
An electrode pattern portion disposed on the second substrate;
It includes a liquid crystal layer made of liquid crystal molecules interposed between the electrode pattern portion and the first substrate,
The liquid crystal molecules of the liquid crystal layer generate a charge amount change due to a piezoelectric effect and a flexoelectric effect by an external stimulus applied to the first substrate,
Detecting an external stimulus applied on the first substrate based on the charge amount change
LCD touch screen panel.
The method of claim 1,
The liquid crystal layer generates an elastic deformation by an external stimulus applied to the first substrate, and a liquid crystal touch that senses an external stimulus applied on the first substrate based on the capacitance of the electrode pattern portion that is changed by the elastic deformation. Screen panel.
The method of claim 1,
The electrode pattern portion includes a first electrode, a second electrode and an insulating layer disposed between the first electrode and the second electrode, the first electrode and the second electrode is a liquid crystal, characterized in that the cross-aligned form Touch screen panel.
In the liquid crystal touch screen panel,
First substrate,
A second substrate disposed opposite the first substrate,
A first electrode disposed under the first substrate,
A second electrode disposed on the second substrate;
It includes a liquid crystal layer made of liquid crystal molecules interposed between the first electrode and the second electrode,
The liquid crystal molecules of the liquid crystal layer generate a charge amount change due to a piezoelectric effect and a flexoelectric effect by an external stimulus applied to the first substrate,
Detecting an external stimulus applied on the first substrate based on the charge amount change
LCD touch screen panel.
The method of claim 4, wherein
According to an external stimulus applied to the first substrate, the arrangement structure of the liquid crystal molecules of the liquid crystal layer is modified to generate a change in the spontaneous polarization direction,
And an external stimulus applied on the first substrate based on a potential difference between the first electrode and the second electrode which changes according to the change in the spontaneous polarization direction.
The method of claim 4, wherein
And an arrangement structure of the liquid crystal molecules of the liquid crystal layer disposed under the region to which the external stimulus is applied is reversed.
The method of claim 4, wherein
And an insulating layer disposed between the first electrode and the liquid crystal layer and between the second electrode and the liquid crystal layer.
The method of claim 4, wherein
And an insulating layer and an auxiliary electrode disposed between the second substrate and the second electrode.
The method of claim 4, wherein
An alignment layer is disposed between the first substrate and the liquid crystal layer or between the second substrate and the liquid crystal layer.
10. The method according to any one of claims 1 to 9,
The liquid crystal layer may include a liquid crystal or liquid crystal polymer having a banana-type molecular structure or a wedge-shaped molecular structure, and the liquid crystal polymer may include any one of a main chain type, a side chain type, a crosslink type, and a dendrimer type liquid crystal polymer. LCD touch screen panel made.
10. The method according to any one of claims 1 to 9,
The liquid crystal of the liquid crystal layer
A liquid crystal touch screen panel having an inclined chiral phase in the same direction or an opposite direction or having an inclined racemic phase.
10. The method according to any one of claims 1 to 9,
The liquid crystal layer is
A liquid crystal touch screen panel having optical anisotropy birefringence.
10. The method according to any one of claims 1 to 9,
The liquid crystal layer is
A liquid crystal touchscreen panel comprising a liquid crystal having a phase structure of at least one of nematec, smetic and cholesteric.

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