WO2010024495A1

WO2010024495A1 - Capacitive type structure of multi-touch input for acquiring location and intensity of force, input device and making method thereof

Info

Publication number: WO2010024495A1
Application number: PCT/KR2008/005889
Authority: WO
Inventors: Jong Ho Kim; Yon Kyu Park; Min Seok Kim; Jae Hyuk Choi; Dae Im Kang
Original assignee: Korea Research Institute Of Standards And Science
Priority date: 2008-08-27
Filing date: 2008-10-08
Publication date: 2010-03-04
Also published as: KR20100025176A; KR101025613B1

Abstract

The present invention relates to an electrostatic-capacity-type touch input structure for measuring contact positions and pressing force in response to a multi-tovch, and more specifically, to a tovch input structure, a manufacturing method thereof, and a tovch input apparatus using thereof, in which interference among a plurality of pressing forces applied when multi-tovch is inputted is minimized by providing a filling material between upper and lower electrode layers, thereby acquiring aixurate positions and strength of the pressing forces.

Description

CAPACITIVE TYPE STRUCTURE OF MULTI-TOUCH INPUT FOR ACQUIRING LOCATION AND INTENSITY OF FORCE, INPUT DEVICE AND MAKING METHOD

THEREOF Technical Field

[1] The present invention relates to an electrostatic-capadty-type touch input structure for measuring contact positions and pressing force in response to a multi-touch, and more specifically, to a touch input structure, a manufacturing method thereof, and a touch input apparatus using thereof, in which interference among a plurality of pressing forces applied when multi-touch is inputted is minimized by providing a filling material between upper and lower electrode layers, thereby acquiring accurate positions and strength of the pressing forces. Background Art

[2] Touch input techniques spotlighted recently are for selecting or inputting a function desired by a user, which are used in a variety of electronic and communication devices such as notebook computers, personal data assistance (PDA), game players, cellular phones, and the like.

[3] I-phone of Apple Inc. is an example of the touch input technique used in a cellular phone. I-phone follows an electrostatic capacity method, in which electrodes 12 and 13 are formed on the upper and lower surfaces of a glass substrate 10 as shown in FIG. 1, and only positions of pressed points are detected. Although the touch input techniques of the prior art as shown in FIG. 1 are advantageous in that a clear screen can be provided since the light emitted from a liquid crystal panel is not hindered when being transferred to a user and it does no harm to the appearance of a cellular phone or the like, when a user performs touch inputs wearing gloves, the inputs are not applied since there is no change in electrostatic capacity. Furthermore, since not a small pressing force corresponding to 150g weight is required when an input is applied, there is a limitation in commercializing the touch input technique in a variety of apparatuses such as small electronic and communication devices as well as large electronic and communication devices. Furthermore, such a touch input technique of the prior art is limited only to acquire positions of multi-touch and cannot detect strength of a pressing force. [4] As a technique related to touch input, there is a tactile sensor of an electrostatic- capacity-type and a method of manufacturing thereof (Korea Patent Publication Gazette No. 10-2008-0054187). As shown in FIG.2, electrodes 56a and 56b are respectively formed on upper and lower substrates 51 and 52, and dome-shape spacer 58 is provided around the electrodes 56b. Such a tactile sensor detects a position and strength of a pressing force by acquiring change of electrostatic capacity.

[5] Fbwever, if a plurality of pressing forces is locally applied to the tactile sensor through multi-toich, although the pressing forces F and F are locally applied, the upper substrate is deformed as shown in FIG. 3 due to an effect of applying the forces to the entire upper substrate 51. Accordingly, when multi-toich is inputted, interference is generated among the pressing forces F and F locally applied to each

1 2 point, and thus there is a limitation in accurately acquiring positions and strength of respective pressing forces F and F . Such an interference phenomenon further severely oxurs when a distance between a plurality of pressing forces F and F is shorter.

[6] Therefore, required is development of a touch input technique that can accurately detect strength and position of a pressing force of each point when a plurality of pressing forces F and F is locally applied through multi-toich. Disclosure of Invention Technical Problem

[7] Accordingly, the present invention has been made in order to solve the above problems, and it is an object of the invention to provide an electrostatic-capacity-type touch input stricture for measuring contact positions and pressing forces in response to a multi-toich and a method of manufacturing thereof, in which strength and positions of the pressing forces can be accurately acquired by blocking interference among a plurality of pressing forces.

[8] Another object of the invention is to provide an electrostatic-capacity-type toich input stricture for measuring contact positions and pressing forces in response to a multi-toich and a method of manufacturing thereof, which can be diversely utilized for a variety of electronic and communication devices using a toich input method as one module. Technical Solution

[9] In order to accomplish the above objects of the invention, according to one aspect of the invention, there is provided an electrostatic-capacity-type toich input structure for multi-toich, comprising: an upper substrate formed with an upper electrode layer on one side, which can be deformed by a touch; a lower substrate provided to be spaced apart from the upper substrate by a certain distance and formed with a lower electrode layer on a side facing the upper electrode layer; an adhesive layer provided along a brim between the upper and lower substrates, for connecting the upper and lower substrates; and a filling material filled in between the upper and lower substrates.

[10] In this regard, the filling material may be an elastic material.

[11] Also, the elastic material may consist of a transparent polymer film, transparent liquid, transparent sol, or transparent gel.

[12] In this case, the transparent gel can be polydimethylsiloxane or silicon.

[13] Also, it is preferable to make the upper and lower substrates to be transparent.

[14] In addition, the upper and lower substrates may be glass or a polymer film.

[15] IVbreover, the adhesive layer is preferable to be provided along a brim of the upper and lower substrates.

[16] Also, the adhesive layer may be a UV hardener.

[17] In this invention, the lower electrode layer may comprise a plurality of lower electrodes, and a spacer is further comprised among the plurality of lower electrodes.

[18] It is preferable for the spacer to have elasticity.

[19] In this instance, it is preferable that the upper and lower electrode layers be electrodes of a stripe shape, and the electrodes formed on the upper and lower electrode layers be provided in plurality to cross each other.

[20] Also, the upper and lower electrode layers may be Indium Tin Oxide (ITO) or

Carbon Nano Tube (CNT).

[21] IVbreover, a distance between the upper and lower substrates can be 0.1 to 100/M.

[22] Also, it is preferable that a thickness of the upper substrate is 100 to 1,500/M.

[23] Also, a side surface of the toich input stricture is in a completely fixed state, and displacement and slope of the side surface are unchangeable.

[24] IVbreover, a side surface of the toich input structure is in a simply fixed state, and displacement of the side surface is unchangeable.

[25] According to another aspect of the present invention, there is provided a toich input apparatus for measuring contact positions and pressing forces, the apparatus comprising an electrostatic-capacity-type toich input stricture for measuring the contact positions and pressing forces in response to a multi-toich, the stricture including: an upper substrate formed with an upper electrode layer on one side, which can be deformed by a toich; a lower substrate provided to be spaced apart from the upper substrate by a certain distance and formed with a lower electrode layer on a side facing the upper electrode layer; an adhesive layer provided along a brim between the upper and lower substrates, for connecting the upper and lower substrates; and a filling material filled in between the upper and lower substrates; a power supply unit for applying voltage to the upper and lower electrode layers; and a detection unit for detecting change of electrostatic capacity of the upper and lower electrode layers, wherein the detection unit includes: an analog amplifier for receiving output of the upper and lower electrode layers through a negative (-) input terminal; a voltage multiplier for receiving output of the analog amplifier and outputting an output voltage amplified by integer times; and a switch provided at a rear end of the voltage amplifier, for controlling the output of the voltage amplifier.

[26] In this regard, the power supply unit supplies voltage of a sinusoidal or square wave.

[27] In the present invention, it is preferable that a minimum frequency of the sinusoidal or square wave may be 10KHz.

[28] Also, it is preferable that the voltage amplifier comprises a first capacitor for receiving the output of the analog amplifier; a first diode provided between the first capacitor and a ground voltage; a second diode connected to a first node between the first capacitor and the first diode; and a second capacitor provided between the second capacitor and the ground voltage, wherein the switch is connected to the second node and controls output.

[29] According to still another spect of the present invention, there is provided a method of manufacturing an electrostatic-capadty-type toirh input stricture for measuring contact positions and pressing forces in response to a multi-toirh, the method comprising the steps of forming an electrode layer on one side of at least two transparent substrates; providing the substrates such that the electrode layers formed on the substrates cross each other; and bonding the substrates by injecting a filling material into an internal space formed between the substrates.

[30] In addition, the present invention may further comprise the step of forming a spacer among a plurality of electrodes formed on any one of the substrates.

[31] Also, the filling material may be sol, gel, or a liquid phase, and the step of injecting the filling material and bonding the substrates may include the steps of forming an adhesive layer along a brim of an upper substrate and a lower substrate remaining an injection hole for injecting the filling material; injecting the filling material through the injection hole; and filling up the injection hole.

[32] It is preferable that the filling material is a solid phase, and the step of injecting the filling material and bonding the substrates includes the steps of positioning the filling material within an inner area between the substrates; and bonding the brim of the upper and lower substrates using the adhesive layer.

Advantageous Effects

[33] Accordingly, according to an embodiment described above, the present invention is advantageous in that a filling material is provided between upper and lower substrates, and thus although a plurality of pressing forces is applied, the pressing forces can be accurately acquired by blocking interference among the pressing forces. [34] Furthermore, it is advantageous in that since strength and positions of pressing forces can be simultaneously acquired, a variety of applications can be provided to users based on the strength and positions of pressing forces. [35] Furthermore, it is advantageous in that since the toich input stricture is easy to manufacture as one module, any type of electronic and communication device employing a touch input method can utilize the toich input stricture.

Brief Description of Drawings [36] Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings. [37] FIG. 1 is a side cross-sectional view showing a first embodiment of a toich input structure implementing multi-toich of the prior art. [38] FIG. 2 is a side cross-sectional view showing a second embodiment of a touch input structure implementing multi-toich of the prior art. [39] FIG. 3 is a view showing deformation of an upper substrate when pressing forces are applied on two points of the toich input stricture of FIG. 2. [40] FIG. 4 is a perspective view showing an electrostatic-capacity-type toich input stricture for measuring contact positions and pressing forces in response to a multi- touch according to the present invention. [41] FIG. 5 is a side cross-sectional view showing the electrostatic-capadty-type touch input stricture of FIG. 4 for measuring contact positions and pressing forces in response to a multi-touch. [42] FIG. 6 is a view showing deformation of an upper substrate when pressing forces are applied at two points by multi-toich when a filling material is not provided. [43] FIG. 7 is a view showing deformation of an upper substrate when pressing forces are applied at two points by multi-toich when a filling material is provided. [44] FIG. 8 is a flowchart illustrating a method of manufacturing an electrostatic- capacity-type toirh input structure for measuring contact positions and pressing forces in response to a multi-toirh according to the present invention.

[45] FIG. 9 is a configuration diagram showing an equivalent circuit according to a first embodiment of a detection unit of a toirh input apparatus for measuring contact positions and pressing forces according to the present invention.

[46] FIG. 10 is a configuration diagram showing an equivalent circuit according to a second embodiment of a detection unit of a touch input apparatus for measuring contact positions and pressing forces according to the present invention.

[47] FIG. 11 shows a graph of overall output according to the embodiment of FIG. 10, which is a graph showing change of overall output according to change of time and electrostatic capacity desired to be measured.

[48] FIG. 12 is a view showing a state of providing a liquid crystal panel at a lower portion of an electrostatic-capacity-type Mmch input structure for measuring contact positions and pressing forces in response to a multi-touch. Mode for the Invention

[49] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the drawings illustrating the embodiments of the invention, elements having like functions will be denoted by like reference numerals and details thereon will not be repeated.

[50] Configuration of toirh input strιcture>

[51] FIG. 4 is a perspective view showing an electrostatic-capacity-type toirh input structure for measuring contact positions and pressing forces in response to a multi- touch according to the present invention, and FIG. 5 is a side cross-sectional view of FIG. 4 taken along the line A-A. The electrostatic-capadty-type toirh input structure for measuring contact positions and pressing forces in response to a multi-toirh according to the present invention comprises an upper substrate 110 where an upper electrode layer 112 is formed, a lower substrate 120 where a lower electrode layer 122 is formed, a filling material 140, and spacers 150.

[52] The upper substrate 110 is a member elastically deformed when a pressing force is applied. The toirh input stricture for multi-toirh according to the present invention is provided with a liquid crystal panel 200 or the like at a lower portion and can be utilized for a touch screen, and the upper substrate 110 is preferably configured of a transparent material. Glass, a polymer film (e.g., a polyester film or a ployimide film), and the like are examples of the transparent material. When the glass is used as the upper substrate 110, it has an advantage of superior durability and shows a char- acteristic of requiring a pressing force of about 7Og weight. Contrarily, in the case of the polymer film, although a small pressing force (about 30g weight) is sufficient to induce change of electrostatic capacity, it has a characteristic of low durability compared with the glass. According, considering such characteristics of materials, the upper substrate 110 is selected to be appropriate to environments of electronic and communication devices using an electrostatic-capacity-type touch input stricture for measuring contact positions and pressing forces in response to a multi-toirh according to the present invention.

[53] The upper substrate 110 is preferably configured to have thickness of about 100 to

1,500/M. If the thickness of the upper substrate 110 is less than 100/M, there could be a problem of durability for enduring a pressing force, and if the thickness of the upper substrate 110 is larger than 1,500/M, measuring sensitivity may be degraded since change of electrostatic capacity according to a pressing force is small.

[54] The lower substrate 120 is a member provided to be spaced apart from the upper substrate 110 by a certain distance, which is preferably configured of a transparent material like the upper substrate 110. The spaced distance between the upper and lower substrates 110 and 120 is configured to be within 100/M, i.e., about 0.1 to 100/M. If the distance between the upper and lower substrates 110 and 120 is less than 0.1/M, it is difficult to accommodate deformation of the upper substrate 110 when a pressing force is applied, and if the distance is larger than 100/M, it can be an obstacle to miniaturize the toirh input structure, and sensitivity of measuring change of electrostatic capacity may be more-or-less degraded.

[55] The upper and lower electrode layers 112 and 122 are respectively formed on one side of the upper and lower substrates 110 and 120. The upper electrode layer 112 formed on one side of the upper substrate 110 and the lower electrode layer 122 formed on one side of the lower substrate 120 are provided in plurality in the form of a strip as shown in FIG. 4. In addition, the upper and lower electrode layers 112 and 122 are provided to in the direction of facing and crossing each other. The electrostatic- capacity-type toirh input structure for multi-touch according to the present invention can be added with a liquid crystal panel 200, and the upper and lower electrode layers 112 and 122 are configured of transparent electrodes. Indium tin oxide (ITO) or carbon nano tube (CNT) is an example of the transparent electrode.

[56] An adhesive layer 130 is a member for connecting the upper and lower substrates

110 and 120, which is preferably provided along the brim of the upper and lower substrates 110 and 120. The adhesive layer 130 also functions as a supporting layer, and an ultraviolet curing adhesive (UV adhesive), for example, can be used as the adhesive layer. The upper and lower substrates 110 and 120 are spaced apart from each other by a certain distance by the adhesive layer 130, and thickness of the adhesive layer 130 is 0.01 to 100/fln.

[57] The filling material 140 is provided between the upper and lower substrates 110 and

120. An elastic material is used as the filling material 140. In addition, a transparent and discolored material is preferably used as the filling material 140. The filling material 140, which is an elastic material, blocks interference among pressing forces when a plurality of pressing forces is applied on the upper substrate 110. Hereinafter, the function of the filling material 140 is described in detail.

[58] When the filling material 140 is not proved, although a plurality of pressing forces is applied, the upper substrate 110 strongly tends to be deformed at a certain point between two points as shown in FIG. 6, rather than being deformed at each of the positions, due to durability of the upper substrate 110. That is, although the pressing forces F and F are applied on two points, the upper substrate 110 is deformed in maximum in between the two positions where the pressing forces are applied. Therefore, it is difficult to acquire accurate positions and strength of the pressing forces at the corresponding positions where a plurality of pressing forces F and F are applied, and sirh a phenomenon strongly occurs as the distance between two points where pressing forces are applied is shorter (a phenomenon of force interference). That is, resolution is degraded in acquiring the pressing forces.

[59] Contrarily, when the filling material 140 is proved, if a plurality of pressing forces F and F is applied, the upper substrate 110 is notably deformed at corresponding points as shown in FIG. 7. This is due to elasticity of the filling material 140. The filling material 140 under the points applied with the pressing forces are pushed outward by the pressure of the pressing forces F and F , and the upper substrate 110 around the

1 2 points applied with the pressing forces F and F is deformed relatively upward by the filling material 140 pushed outward. In other words, deformation of the upper substrate 110 is effectively responded at the points where the pressing forces F and F are applied compared with the case where the filling material 140 is not provided. Accordingly, when the pressing forces F and F are applied to two points, interference

1 2 between the pressing forces is blocked, unlike the case of FIG. 6 where deformation of the upper substrate 110 is notably developed. [60] For example, a transparent polymer film, transparent liquid, transparent sol, transparent gel, or the like can be used as the filling material 140. Examples of the transparent gel used as the filling material 140 include silicon and polydimethylsiloane (PDMS). In addition, in order to minimize affect of environment where the touch input structure is placed in acquiring the strength and positions of the pressing forces, a material resistive to thermal expansion or a non-condictive material (e.g., non- condictive oil or the like) is preferably used as the filling material 140.

[61] The spacer 150 is provided among a plurality of lower electrodes 122. The spacer

150 is a also member for blocking interference among pressing forces when a plurality of pressing forces is applied, for which an elastic material is preferably used. Any elastic material like the filling material 140 can be used as the spacer 150 regardless of its type. In addition, the spacer 150 can be diversely configured in the form of a dome, a hexahedron, or the like, and its form is not restricted.

[62] The side surface of the electrostatic-capacity-type toich input structure for measuring contact positions and strength in response to a multi-toich according to the present invention having the stricture described above can be configured in a completely fixed state or a simply supported state. The completely fixed state is a state where the displacement and slope of the side surface are unchangeable, and the simply supported state is a state where the displacement of the side surface is unchangeable.

[63] <Manufacturing method>

[64] Hereinafter, a method of manufacturing an electrostatic-capacity-type toich input structure for measuring contact positions and pressing forces in response to a multi- touch according to the present invention will be described with reference to the accompanying drawings. FIG. 8 is a flowchart illustrating a method of manufacturing a touch input stricture according to the present invention.

[65] First, an electrode layer is formed on one side of at least two substrates SlOO. A transparent material is preferably used as the substrate. A thermal chemical vapor deposition method is an example of the method of forming the electrode layer. A plurality of electrodes is formed in the shape of a strip, and the plurality of electrodes is provided in parallel. The electrode layer can be formed using Indium Tin Oxide or Carbon Nano Tube.

[66] One of the transparent substrates formed with the electrode layer in sich a manner is used as the upper substrate 110, and the other one is used as the lower substrate 120. Hereinafter, the electrode layer formed on the upper substrate is referred to as an upper electrode layer 112, and the electrode layer formed on the lower substrate is referred to as a lower electrode layer 122.

[67] After forming the electrode layer, the spacer 150 can be formed among a plurality of electrodes formed on any one of the two substrates S 150. The spacer 150 preferably has a characteristic of elasticity, and the substrate formed with the spacers 150 can be used as the lower substrate 120 as shown in FIG. 5.

[68] Next, the two substrates formed with the electrode layer are placed to be bonded together. At this point, the substrates are placed sirh that the electrode layers formed on respective substrates cross each other S200.

[Φ] Next, the substrates are bonded together so that the electrode layers respectively formed on the upper and lower substrates 110 and 120 to face with each other. At this point, a filling material is provided between the upper and lower substrates S300. The upper and lower substrates 110 and 120 are bonded sirh that the upper and lower electrode layers 112 and 122 cross each other. A UV hardener, for example, can be used as the adhesive layer 130. The filling material 140 is an elastic material, sirh as a solid phase like a polymer film, a liquid phase like two-liquid type silicon, gel, or sol, and each of the cases will be described.

[70] If the filling material 140 is a solid phase, the filling material 140 is placed in the inner area between the upper and lower substrate 120 S310. At this point, the filling material is preferably configured to be a little bit smaller than the upper and lower substrates 110 and 120 to secure a space for forming the adhesive layer 130. Next, the adhesive layer 130 is formed along the brim of the upper and lower substrates 110 and 120 where the filling material 140 is provided, and the upper and lower substrates 110 and 120 are bonded together S320. In this case, the filling material 140 and the adhesive layer 130 are formed to have the same thickness so that there may be no gap in the area where the filling material 140 is provided, i.e., in the inner area formed by bonding the upper and lower substrates 110 and 120.

[71] If the filling material 140 is gel, sol, or a liquid phase, first, the upper and lower substrates 110 and 120 are bonded together using the adhesive layer 130. At this point, the upper and lower substrates 110 and 120 are bonded remaining an injection hole for injecting the filling material 140 S310' A space is formed inside by forming the adhesive layer 130 along the brim of the upper and lower substrates 110 and 120. Then, the filling material 140 is injected through the injection hole S320' The injected filling material 140 is fully filled in the inner space. If there is a gap in the inner space between the upper and lower substrates 110 and 120 into which the filling material 140 is injected, it is difficult to block interference among a plurality of pressing forces, and thus resolution is degraded in acquiring positions and strength of the pressing forces. If injection of the filling material 140 is completed, the injection hole is filled up using the adhesive layer 130 S330' In this case, it is also preferable not to form a gap in the inner area formed by bonding the upper and lower substrates 110 and 120.

[72] <Toirh input apparatus>

[73] FIG. 9 is a state diagram showing a first embodiment of the detection unit for detecting strength and positions of pressing forces among the configuration of a touch input apparatus for multi-toirh according to the present invention. The touch input apparatus for multi-toirh according to the present invention includes a teach input structure and a detection unit. Preferably, a teach input structure where the upper and lower electrode layers 112 and 122 are formed to face with each other in a matrix form is used.

[74] An input terminal and an output terminal are connected to each of the electrode layers 112 and 122. Voltage of a sinusoidal wave Vi is applied to the input terminal 301, and output of the output terminal 302 is connected to the negative (-) input terminal of an analog amplifier (OPAMP) 400. The positive (+) input terminal of the analog amplifier 400 is grounded, and a peak detection unit 500 for detecting a peak amplitude value of output voltage is provided at the output terminal.

[75] An output value Vout at the output terminal of the analog amplifier 400 is as shown in mathematical expression 1.

^[76] Cvix

Vout = - ?- Vi Cr

[77] (Cpix: electrostatic capacity to be measured, Cr: feedback electrostatic capacity of analog amplifier)

[78] By this relation, if a sinusoidal wave Vi is applied to the input terminal, amplitude changed depending on the change of electrostatic capacity between the upper and lower electrode layers 112 and 122 is amplified to a certain level by the analog amplifier 400 of the output terminal. The signal amplified as such is detected through the peak detection unit 500, and thus the change of electrostatic capacity is detected from the peak amplitude value, thereby detecting the positions and strength of pressing forces.

[79] FIG. 10 shows a second embodiment of a detection unit for detecting strength and positions of pressing forces by outputting a signal from a teach input structure for multi-teach. For the convenience of explanation, only one electrostatic capacity Cpix to be detected from the teach input stricture is shown in the figure.

[80] An input terminal and an output terminal are connected to each of the electrode layers 112 and 122. Voltage of a sinusoidal or square wave Vi is applied to the input terminal 301 from a power supply unit 300, and output of the output terminal 302 is connected to the negative (-) input terminal of the analog amplifier (OPAMP) 400. The minimum frequency of the sinusoidal or square wave applied to the input terminal is lOKFJz, i.e., preferably lOKFJz or more. The positive (+) input terminal of the analog amplifier 400 is grounded. A resistor R and a capacitor Cr are connected in parallel between the negative (-) input terminal and the output terminal of the analog amplifier 400. For example, a resistor of 50kΩ or more and a capacitor of about 3pF can be used. [81] Output voltage V from the output terminal of the analog amplifier 400 is applied to a voltage multiplier 600. The voltage multiplier 600 comprises a first capacitor C and a first diode D provided between the output voltage V and the ground voltage GND of the analog amplifier 400, a second diode D provided between a first node N and a second node N , i.e., between the first capacitor C and the first diode D , and a second

2 1 1 capacitor C provided between the second node N and the ground voltage GND. At this point, the first capacitor C and the second capacitor C have the same order. For example, the first and second capacitors C and C of 1OnF can be used.

1 2

[82] A switch 700 is provided between the second node N and the ground voltage GND, which enables to acquire an output amplified by integer times through the voltage multiplier 600. If the switch 700 is in an open state, the second capacitor C of the voltage multiplier 600 is charged and may detect overall output V related to the result pressing forces according to the present invention. If the switch 700 is in a closed state, the second capacitor C is discharged, and the overall output V becomes '0' FIG. 11

2 result is a graph showing the overall output V according to sirh a switching. At this result point, the slope of the graph is a time constant of RC .

[83] As is known from the graph shown in FIG. 11, in the case of A, electrostatic capacity to be measured is Cpix-a, and output according thereto is Vresult-a. In the case of B, electrostatic capacity to be measured is Cpix-b, and output according thereto is Vresult-b. (Cpix-a is larger than Coix-b)

[84] As shown in FIG. 11, in the toirh input stricture, the electrostatic capacity Cpix to be measured is capacitances of the electrode layers 112 and 122 to which pressing forces are applied, and the overall output V is increased as the electrostatic capacity result

Cpix is higher. In other words, it can be confirmed that a further higher change of electrostatic capacity is derived by the pressing forces in the case of A showing a further higher overall output value, compared with the case of B. [85] In the present embodiment configured with the voltage multiplier 600 and the switch 700, accuracy of the overall output is greatly increased compared with the first embodiment described above.

[86] <M)dified embodiment

[87] FIG. 12 is a perspective view showing a state of providing a liquid crystal panel 200 at a lower portion of an electrostatic-capacity-type teach input stricture for measuring contact positions and pressing forces in response to a multi-teach according to the present invention. An organic light emitting diode (OLED), an electro-luminescent display (ELD), a liquid crystal display (LCD), a plasma display panel (PD), or the like can be used as the liquid crystal panel. Industrial Applicability

[88] Although the present invention has been described with reference to several preferred embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and variations may oxur to those skilled in the art, without departing from the scope of the invention as defined by the appended claims.

Claims

[I] An electrostatic-capadty-type touch input structure for measuring contact positions and pressing forces in response to a multi-touch, the structure comprising: an upper substrate formed with an upper electrode layer on one side, which can be deformed by a touch; a lower substrate provided to be spaced apart from the upper substrate by a certain distance and formed with a lower electrode layer on a side facing the upper electrode layer; an adhesive layer provided along a brim between the upper and lower substrates, for connecting the upper and lower substrates; and a filling material filled in between the upper and lower substrates. [2] The structure aαjording to claim 1, wherein the filling material is an elastic material. [3] The structure aαjording to claim 2, wherein the elastic material is a transparent polymer film, transparent liquid, transparent sol, or transparent gel. [4] The structure aαjording to claim 3, wherein the transparent gel is poly- dimethylsiloxane or silicon. [5] The structure aαjording to claim 1, wherein the upper and lower substrates are transparent. [6] The structure aαjording to claim 5, wherein the upper and lower substrates are glass or a polymer film. [7] The structure aαjording to claim 1, wherein the adhesive layer is provided along a brim of the upper and lower substrates.

[8] The structure aαjording to claim 7, wherein the adhesive layer is a UV hardener.

[9] The structure aαjording to claim 1, wherein the lower electrode layer comprises a plurality of lower electrodes, and a spacer is further comprised among the plurality of lower electrodes. [10] The structure aαjording to claim 9, wherein the spacer has elasticity.

[I I] The structure aαjording to claim 1, wherein the upper and lower electrode layers are electrodes of a stripe shape, and the electrodes formed on the upper and lower electrode layers are provided in plurality to cross each other.

[12] The structure aαjording to claim 1, wherein the upper and lower electrode layers are Indium Tin Oxide (ITO) or Carbon Nano Tube (CNT). [13] The stricture aEording to claim 1, wherein distance between the upper and lower substrates is 0.1 to 100/M.

[14] The stricture ai-cording to claim 1, wherein thickness of the upper substrate is

100 to 1,500/M.

[15] The stricture ai-cording to claim 1, wherein a side surface of the toich input stricture is in a completely fixed state, and displacement and slope of the side surface are unchangeable.

[16] The stricture ai-cording to claim 1, wherein a side surface of the toich input stricture is in a simply fixed state, and displacement of the side surface is unchangeable.

[17] A toich input apparatus for measuring contact positions and pressing forces, the apparatus comprising: an electrostatic-capacity-type toich input structure for measuring the contact positions and pressing forces in response to a multi-touch, the stricture including: an upper substrate formed with an upper electrode layer on one side, which can be deformed by a toich; a lower substrate provided to be spaced apart from the upper substrate by a certain distance and formed with a lower electrode layer on a side facing the upper electrode layer; an adhesive layer provided along a brim between the upper and lower substrates, for connecting the upper and lower substrates; and a filling material filled in between the upper and lower substrates; a power supply unit for applying voltage to the upper and lower electrode layers; and a detection unit for detecting change of electrostatic capacity of the upper and lower electrode layers, wherein the detection unit includes: an analog amplifier for receiving output of the upper and lower electrode layers through a negative (-) input terminal; a voltage multiplier for receiving output of the analog amplifier and outputting an output voltage amplified by integer times; and a switch provided at a rear end of the voltage amplifier, for controlling the output of the voltage amplifier.

[18] The stricture ai-cording to claim 17, wherein the power supply unit supplies voltage of a sinusoidal or square wave.

[19] The stricture ai-cording to claim 18, wherein a minimum frequency of the sinusoidal or square wave is lOKHz.

[20] The stricture ai-cording to claim 17, wherein the voltage amplifier comprises: a first capacitor for receiving the output of the analog amplifier; a first diode provided between the first capacitor and a ground voltage; a second diode connected to a first node between the first capacitor and the first diode; and a second capacitor provided between the second capacitor and the ground voltage, wherein the switch is connected to the second node and controls output. [21] A method of manufacturing an electrostatic-capacity-type toirh input stricture for measuring contact positions and pressing forces in response to a multi-toirh, the method comprising the steps of: forming an electrode layer on one side of at least two transparent substrates; providing the substrates such that the electrode layers formed on the substrates cross each other; and bonding the substrates by injecting a filling material into an internal space formed between the substrates. [22] The method according to claim 21, further comprising the step of forming a spacer among a plurality of electrodes formed on any one of the substrates. [23] The method according to claim 21, wherein the filling material is sol, gel, or a liquid phase, and the step of injecting the filling material and bonding the substrates includes the steps of: forming an adhesive layer along a brim of an upper substrate and a lower substrate remaining an injection hole for injecting the filling material; injecting the filling material through the injection hole; and filling up the injection hole. [24] The method according to claim 21, wherein the filling material is a solid phase, and the step of injecting the filling material and bonding the substrates includes the steps of: positioning the filling material within an inner area between the substrates; and bonding the brim of the upper and lower substrates using the adhesive layer.