KR101029043B1 - Force-based touch panel based on capacitance - Google Patents

Abstract

PURPOSE: A power based capacitive touch panel is provided to supply a touch panel of high accuracy by sensing a touch location in an electrostatic capacitive type. CONSTITUTION: A flat spring(10) includes a supporting part, a connecting part, and a pushing part. A PCB(Printed Circuit Board)(30) has an electrode which faces the pushing part and is arranged in the flat spring. A spacer(20) is separated from the pushing part. A coordinate controlling part(40) senses the electrostatic capacity between the electrode and the pushing part.

Description

Force-Based Capacitive Touch Panels {FORCE-BASED TOUCH PANEL BASED ON CAPACITANCE}

The present invention relates to a force-based capacitive touch panel, and more particularly, to a force-based capacitive touch panel applying a leaf spring structure.

Touch panels are used in various electronic fields because they can provide a simple and intuitive interface for inputting information. In particular, a transparent touch screen, which is a kind of touch panel, is widely used in display devices such as mobile phones and personal digital assistants (PDAs).

In such a touch panel, various methods such as resistive, acoustical, and capacitive are used to sense a touch position by a finger or a passive object.

Resistive touch panels include two conductive plates, and the touch position is sensed by a finger or a passive object pressing the two conductive plates together, but disadvantages are low transparency and low durability. Acoustic touch panels also emit sound along the surface of the touch panel and detect the touch position by measuring the interaction between the sound and the passive object, but the disadvantages of manufacturing cost are high and precision is low.

On the other hand, capacitive touch panels use the principle of sensing the touch position by measuring the amount of change in capacitance between electrodes whose distances change from each other due to the pressure of the touch, and can be implemented with a simple structure. This is done.

An object of the present invention is to provide a touch panel that can accurately detect whether the touch, the touch position and the touch pressure using the capacitance.

In addition, an object of the present invention is to provide a touch panel that can be applied to a display device and used as a touch screen.

The present invention for achieving the above object is made of a flat plate made of a conductive material, and partially cut the plate so that the support portion corresponding to the circumferential portion of the plate and the boundary between the support portion and the inner region of the support portion A plurality of cutouts, a plurality of connecting portions corresponding to portions not cut by the cutouts at the boundary line, and corresponding to the inner region of the support portion, and pressed according to the user's pressing and restored by elasticity of the connecting portion A flat spring having a portion; A PCB substrate having at least one electrode disposed at a position opposite to the pressing portion of the flat plate spring and arranged in parallel to the flat plate spring; A spacer disposed between the PCB substrate and the support portion such that the pressing portion of the flat plate spring and the at least one electrode of the PCB substrate maintain a constant distance from each other when there is no user press; Coordinate measurement for sensing the capacitance between the pressing portion and the at least one electrode and determining at least one of the pressing portion, the position of the pressing and the strength of the pressing by the sensed capacitance. It provides a force-based capacitive touch panel comprising a portion.

The flat plate spring may further include a light transmitting part formed by removing the flat plate from a part of the pressing part, and the light transmitting part may be fixed to a portion of the pressing part where the flat plate is not removed to cover the light transmitting part. The floodlight plate is formed.

In addition, the floodlight plate is attached to the edge portion through a spacer having a predetermined thickness.

In addition, the floodlight plate is characterized in that it has a larger size than the outer shape of the pressing portion.

In addition, an electrode pattern is formed on the floodlight panel so as to face each of the electrodes formed on the PCB substrate, and the coordinate measuring unit is pressed by the capacitance between the electrode of the PCB substrate and the electrode pattern of the floodlight plate. It is determined whether at least one of the negative press, the position of the press, and the intensity of the press.

According to the touch panel as described above, since the manufacturing method can form a touch panel using a simple flat spring, and the touch position can be sensed using a capacitive method, the manufacturing method is simple and inexpensive. It is possible to provide a touch panel with high accuracy.

In addition, by forming a portion of the touch panel into an empty space, the display screen of the display device disposed behind the display panel may be transmitted to thereby be applied as a touch screen.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 is a diagram illustrating a configuration of a touch panel according to an exemplary embodiment of the present invention. According to FIG. 1, the touch panel 100 according to an exemplary embodiment of the present invention includes a flat plate spring 10, a spacer 20, a PCB substrate 30, and a coordinate measuring unit 40. .

The flat plate spring 10 is formed of a flat plate-like structure, and forms a boundary line B between a support part 12 corresponding to a circumferential portion of the flat plate and an inner region of the support part 12 and the support part 12. A plurality of incisions 14 formed by partially cutting the plate so as to be supported, a plurality of connecting portions 16 supporting the inner region of the support part 12 corresponding to a portion of the plate not cut by the incision 14; And a pressing part 18 corresponding to an inner region of the support part 12 bounded by the boundary line B. In this case, the pressing unit 18 is pressed according to the user's pressing, and when the user's pressing is released, the pressing unit 18 is restored to a state before being pressed by the elasticity of the connecting unit 16.

In addition, the flat spring 10 is preferably made of a conductive material, in particular a metallic material.

The PCB board | substrate 30 is arrange | positioned so that it may face in parallel with the flat plate spring 10. FIG. In addition, at least one electrode 32 is disposed at a portion of the PCB substrate 30 that faces at least the pressing portion 18 of the flat plate spring 10.

The spacer 20 is intended to maintain a constant distance between the flat plate spring 10 and the PCB substrate 30 facing each other when the user does not press against the pressing portion 18. It is disposed between the support 12 of the flat plate spring 10 and the PCB substrate 30.

At this time, the support portion 12 and the PCB substrate 30 of the flat plate spring 10 is preferably fixed to each other by being coupled to each other through the spacer 20, for this purpose, the spacer 20 of one side of the flat plate spring 10 Various attachment methods may be used for attaching the support 12 to the opposite side and for attaching the PCB substrate. The adhesive method may include a double-sided tape, an adhesive, solder bonding, welding, rivet bonding, bolt (screw) bonding, and the like (to be described later with reference to FIG. 20).

The coordinate measuring unit 40 is electrically connected to a part of the flat plate spring 10 made of a conductive material and the electrode 32 of the PCB substrate 30, respectively, and the electrode 32 and the electrode of the PCB substrate 30. The magnitude and amount of change in capacitance generated between a part of the pressing portions 18 of the flat plate springs opposite to each other are measured.

Then, by using the measured electrostatic capacity, whether the pressing occurred on the pressing portion 18 of the flat plate spring, the position of the pressing (coordinate), and the strength of the pressing is measured.

On the other hand, when the flat spring 10 is made of an insulating material, the electrode (electrode pattern) 34 is formed by a conductive material on at least a portion of the PCB substrate 30 facing the electrode 32, and the coordinate measuring unit In the 40, the capacitance may be sensed between the electrode 32 of the PCB substrate 30 and the electrode pattern 34 formed on the flat plate spring 10. It is possible to detect the intensity of the pressing on the pressing portion 18 using the amount or magnitude of change in capacitance.

One electrode 32 may be arranged to detect only the user's pressing and the intensity thereof, but the pressing portion (2) may be used to detect the pressing position in two-dimensional coordinates using the pressing unit 18 as a coordinate plane. At least three spots in 18) should be placed.

On the other hand, in order to move and restore the pressing portion 18 according to the user's pressing in this way, in particular, it is preferable that the connecting portion 16 and the support portion 12 has elasticity against torsion or bending. However, it is preferable that the pressing portion 18 in which the pressing of the user is made to have a firmness so as not to be twisted or bent by the pressure by the pressing.

Usually, since the flat spring 10 is made of a single material such as metal, it is preferable that the flat spring 10 is selected from a material that can satisfy elasticity and robustness at the same time.

In addition to the material of the flat spring 10, the width of the support portion 12, the width and length of the cutout portion 14, the width and length of the connecting portion 16, the pressing portion 18 and the support portion 12 and The thickness of the flat plate in each portion such as the connecting portion 16, the shape of the cutout portion 14 and the connecting portion 16, the size and shape of the spacer 20 and the arrangement position may be appropriately set and applied.

The method of detecting the coordinates of the pressing acting on the pressing unit 18 by using the capacitance will be described with reference to FIGS. 2 to 11.

2 is a diagram for analyzing the relationship between the force acting on the cantilever beam and the elastic deformation of the cantilever beam. Figure 2 (a) is a conceptual diagram for analyzing the elastic deformation of the cantilever beam, Figure 2 (b) is a view showing an equivalent spring model for the cantilever beam of Figure 2 (a).

First, as shown in (a) of FIG. 2, when the force P is applied vertically to the free end of the horizontal cantilever beam having a length L, the cantilever beam sags by the displacement δ. If you organize this into a formula,

가 된다. 여기에서, E: 탄성 계수, I: 관성 모멘트이다.

Becomes Here, E is the elastic modulus and I is the moment of inertia.

This cantilever analysis is equivalently modeled with a single spring arranged vertically as in FIG. 2 (b). Here is how to organize each parameter

이므로,

로 된다.

Because of,

.

In other words, the force acting on the cantilever beam can be modeled by a simple spring structure. Therefore, the cantilever can be used as a spring in the elastic region where a certain amount of deformation occurs. By using this property, in the present invention, a spring is formed at a predetermined position with respect to a flat plate to which the user's pressing is applied to give a reaction force, and the deformation and the force of the spring are measured to detect the strength and position of the force applied to the flat plate. Use the principle of

3 to 6 show various types of flat springs in the touch panel according to the present invention. Meanwhile, in the touch panel 100 shown in FIGS. 3 to 6, the flat plate is removed from at least a portion (particularly, the center portion) of the pressing portion 18 of the flat plate spring 10 to form the light transmitting portion 18A. The light transmitting plate 18B is disposed in the light transmitting portion 18A. The light transmitting plate 18B is fixed to the part of the press part 18 in which the flat plate was not removed (parts other than the part removed to form the light transmitting part, that is, the edge part of the press part) by adhesion or the like.

The floodlight plate 18B may be attached through a separate spacer 20 having a predetermined thickness.

In addition, it is preferable that the light transmitting plate 18B is made of a material such as glass that is not twisted or bent by the pressure of the user's pressing.

In addition, in the structure including the light transmitting plate 18B, the electrode 32 formed on the PCB substrate 30 to detect the capacitance is opposed to the edge portion of the pressing portion 18 where the flat plate is not removed. It is preferred to be placed in position.

Alternatively, the electrode pattern 34 is formed on the light-transmitting plate 18B attached to the pressing part 18 with a transparent electrode, and the electrode 32 is placed on the PCB substrate 30 at a position opposite to the electrode pattern 34. In addition, the coordinate measuring unit 40 may be configured to detect the press by the capacitance between the electrode pattern 34 and the electrode 32. Such a structure may be applied when the edge portion of the pressing portion 18 is formed to be very narrow, or when the flat spring 10 is formed of an insulating material.

In the case of forming the light transmitting portion 18A in this manner, it is preferable that the PCB substrate 30 also has an opening (not shown) in a form corresponding to the light transmitting portion 18A so as to form a light transmitting structure as a whole. .

According to the flat spring 10 having such a structure, since the display from the display device on the rear side can be transmitted through the pressing portion 18 and the light transmitting portion 18A formed on the PCB substrate 30, the display apparatus can be seen. Overlaid on the surface of the to be able to function as a touch screen that can receive a user's touch.

First, Figure 3 is a view showing an example of configuring a flat spring in the touch panel according to the present invention. FIG. 3 (a) shows a shape in which the incision portion 14 and the connecting portion 16 are formed by cutting while forming the support portion 12 with a predetermined width from one side of the rectangular flat spring 10 as shown in FIG. 1. Shows.

FIG. 3B is a side cross-sectional view of the touch panel of FIG. 3A. From above, it is possible to see a structure in which the floodlight plate 18B, the flat plate spring 10, the spacer 20, and the PCB substrate 30 are sequentially stacked.

FIG. 3C is a plan view of the touch panel of FIG. 3A. In this figure, the shape of the cutout 14, the shape of the spacer 20 (shown as the spacer is shown above) and the shape of the transparent plate 18B can be seen.

3 (d) shows an equivalent model of the pressing portion and the spring in the flat spring structure of this type. According to the flat spring 10 as shown in FIG. 3 (a), the reaction force by the spring acts on each corner (part where the connection part is located) of the square corresponding to the shape of the press part 18 (elastic action position). It can be interpreted as

4 is a view showing another example of configuring a flat spring in the touch panel according to the present invention.

4 (a) is a rectangle formed by a boundary line B between a support part 12 having a predetermined width at each side and an inner region of a rectangular flat plate spring 10, and connecting each corner of the rectangle. (16) and shows a form in which the incision 14 is formed on each side except this.

FIG. 4B is a side cross-sectional view of the touch panel of FIG. 4A. From above, it is possible to see a structure in which the floodlight plate 18B, the flat plate spring 10, the spacer 20, and the PCB substrate 30 are sequentially stacked.

FIG. 4C is a plan view of the touch panel of FIG. 4A. It can be seen that the spacer 20 is disposed at the central portion of each side of the support 12. The equivalent model for this flat spring structure is the same as that shown in Fig. 3 (d) because the connecting portions 16 which act on the pressing portions (light transmitting plate) 18 are located at each corner.

5 is a view showing another example of configuring a flat spring in the touch panel according to the present invention. FIG. 5 (a) shows a form in which the connection portion 16 is formed at the center portion of each side of the inner region and the cutout portion 14 is formed to include each corner.

FIG. 5B is a plan view of the touch panel of FIG. 5A. The spacer 20 is disposed at each corner portion of the flat spring 10.

FIG. 5C shows an equivalent model of the pressing portion and the spring in the flat spring structure of this type. That is, it can be interpreted that the reaction force by the spring acts on the center portion (part where the connection portion is located) of each side of the rectangle corresponding to the shape of the pressing portion 18.

6 is a view showing still another example of configuring a flat spring in the touch panel according to the present invention. 6 (a) shows a form in which the cutouts 14 are formed so that the connecting portions 16 can be formed at each corner and the center portion of the boundary line with respect to the inner region of the support 12.

FIG. 6 (b) is an equivalent model for the flat spring formed with the cutout and the connecting part as shown in FIG. This can be interpreted as working.

Various structures may be applied in addition to the shape of the various flat springs described above with reference to FIGS. 3 to 6.

FIG. 7 is a diagram for setting each parameter in order to analyze the relationship of the displacement at each point of the pressing portion by the force acting by the pressing in the flat spring having the structure as shown in FIG. 3.

7 (a) shows the shape of the flat plate spring 10 and the parameters set in each part. Here, when the center of the pressing part 18 is made into the center of the coordinate axis, the point where the pressing of which the magnitude | size of the force acts is represented by the position (x, y). And longitudinal length of the pressing portion 18 from the center coordinate is defined in 2ℓ _1, the horizontal direction length is defined as a 2ℓ _{2. 1} is the longitudinal distance from the center of the connecting portion 16 to which the elasticity, which is a reaction force against the pressing, is applied, to the coordinate center, and ₂ is the horizontal distance from the center of the connecting portion 16 to the coordinate center. n is a normal to the same plane as the pressing part 18, and this normal can be represented by n = a i + b j + c k .

7 (b) shows each parameter set for the pressing unit as described above in a plan view.

FIG. 7C is a diagram illustrating a case where a press occurs at the position F and a displacement occurs at the press portion. In FIG. 7C, it can be seen that the normal of the plane n is inclined with respect to the Z axis. Here, R ₁ , R ₂ , R ₃ , and R ₄ are vectors representing the reaction force of the spring occurring at the elastic action position, and f ₁ , f ₂ , f ₃ , and f ₄ are each side of the pressing part 18. Represents a straight line equation.

Using this figure, the interpretation of the pressing F acting on the position (x, y) is derived as follows.

First, the planar equation for the plate constituting the pressing part 18 may be expressed as ax + by + cz + d = 0 (here, n = a i + b j + c k ). At this time, the linear equation for each side of the plate,

f ₁ : Z = -By -AL2 -D

f ₂ : Z = -Ax -BL1 -D

f ₃ : Z = -By + AL2 -D

f ₄ : Z = -Ax + BL1 -D

, Where A = a / c, B = b / c, and D = d / c.

If the displacement (a deflection amount) at each elastic acting position is Z ₁ , Z ₂ , Z ₃ , Z ₄ , the equation for each is

Z ₁ =-(Bℓ ₁ ) -AL ₂ -D = -Bℓ ₁ -AL ₂ -D

Z ₂ = -Aℓ ₂ -BL ₁ -D

Z ₃ = -Bℓ ₁ + AL ₂ -D

Z ₄ = -Aℓ ₂ + BL ₁ -D

Therefore, the relationship between the reaction forces R ₁ , R ₂ , R ₃ , R ₄ and the deflection amount Z ₁ , Z ₂ , Z ₃ , Z ₄ is

R ₁ = KZ ₁

R ₂ = KZ ₂

R ₃ = KZ ₃

R ₄ = KZ ₄

It is summarized as having.

At this time, since the force (moment) in the Z-axis direction is 0,

This equation is summarized as follows.

ΣF = -F -4KD = 0

D = -F / 4K --①

In the same way, if the sum of the moments in the X-axis direction and the Y-axis direction is 0, the following relationship can be derived.

ΣM _x = -Fy + R ₁ (-ℓ ₁ ) + R ₂ (L ₁ ) + R ₃ (ℓ ₁ ) + R ₄ (-L ₁ ) = 0

Fy = K (2A (ℓ ₁ L ₂ -L ₁ ℓ ₂ ) -2B (ℓ ₁ ² + L ₁ ² )) --②

ΣM _y = -Fx + R ₁ (L ₂ ) + R ₂ (ℓ ₂ ) + R ₃ (-L ₂ ) + R ₄ (-ℓ ₂ ) = 0

Fx = K (-2A (L ₂ ² + ℓ ₂ ² ) + 2B (ℓ ₁ L ₂ -L ₁ ℓ ₂ )) --③

Using equations ①, ②, ③, a, b, c, d or A, B of the plane normal vector, the magnitude of the force F, the position of the force (x, y), and the magnitude of the plate L ₁ , L ₂ , summarized by the variables of the reaction positions ℓ ₁ , ℓ ₂ are as follows.

Using these results, the following practical application can be obtained.

(1) for square plates

FIG. 8 illustrates a process of detecting a position (x, y) of a press by a displacement measured at each side when a press of a force of F acts on a square plate having a 60 mm side. It is for the drawing.

According to FIG. 8, in the case where the spring (reaction force position) of the equivalent model is located at a position 5 mm away from each corner of the plate, the position (reaction force measurement point) for measuring the displacement of the plate is variously set. Shows. That is, in the case of ①, the reaction force measurement point is the same as the spring position, in the case of ②, the reaction force measurement point is the center of each side of the plate, and in the case of ③, the reaction force measurement point is each corner of the plate. The case shows that the reaction force measurement point is 10 mm away from the center of each side of the plate.

Here, the spring coefficient is set to K = 1.

In addition, pressing acts on the position which is (10,5) from a coordinate origin, and the force intensity F is set to one. Based on these numbers, A = -1/305, B = -1/610, and D = -0.25.

First, in the case of ①, the following measurement results can be obtained.

Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 30 -25 0.307377 9.221311 -7.68443 25 30 0.381148 9.528689 11.43443 -30 25 0.192623 -5.77869 4.815574 -25 -30 0.118852 -2.97131 -3.56557 ΣR _i = 1 Σx _i R _i = 10 Σy _i R _i = 5

로 나타나는 것을 확인할 수 있어, ΣR_i = F = 1의 관계와 같으므로, 식이 바르다는 것을 알 수 있다. 이 네지점의 반력으로부터 역으로 힘 F의 위치는 다음과 같이 구해진다.That is, since the deflection amount Z _i of each measuring point is in a relationship of R _i = KZ _i , and K = 1, it is in a relationship of R _i = Z _i . In the table above,

It can be seen that the equation is the same as the relationship of ΣR _i = F = 1, indicating that the equation is correct. The position of the force F is inversely calculated from the reaction force of these four points.

Therefore, by substituting x = 10 and y = 5, the reaction force R _i is obtained from the deflection amount Z _i at the reaction force measuring point, and the position of the force F (x, y) from the coordinates (x _i , y _i ) of R _i and R _i . ) Can be found correctly.

In the same way, the calculation results were examined while changing the position of the deflection measurement.

The results measured at the points of ② are shown in the following [Table 2].

Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 30 0 0.348361 10.45082 0 0 30 0.29918 0 8.97541 -30 0 0.151639 -4.54918 0 0 -30 0.20082 0 -6.02459 One 10 5

The results measured at points ③ are shown in the following [Table 3].

Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 30 -30 0.29918 8.97541 -8.97541 30 30 0.397541 11.92623 11.92623 -30 30 0.20082 -6.02459 6.02459 -30 -30 0.102459 -3.07377 -3.07377 One 10 5

The results measured at points ④ are shown in the following [Table 4].

Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 30 10 0.364754 10.94262 3.647541 -10 30 0.266393 -2.66393 7.991803 -30 -10 0.135246 -4.05738 -1.35247 10 -30 0.233607 2.336066 -7.0082 One 10 5

The results shown in [Table 1], [Table 2], [Table 3], and [Table 4] are as follows.

9 is a diagram for analyzing measurement results as shown in the above table. If the distance from the coordinate origin of the plate on which the reaction force is measured to each reaction force measurement point is defined as S1, S2, S3, S4, respectively,

S1 = 39.05

S2 = 30

S3 = 42.4264

S4 = 31.622

Measured in terms of x _i and y _i ,

The relationship is obtained, whereby the position (x, y) to which the force F is applied can be obtained regardless of the reaction force measurement position.

Therefore, in the case of a square, if the reaction force measurement position has the positional relationship described above, the position with respect to the pressing F can be calculated.

(2) In the case of rectangular flat plate, the reaction force is at each corner

FIG. 10 illustrates a process of detecting the position (x, y) of the pressing by the displacement measured at each side when the pressing force having the magnitude of F acts on the rectangular flat plates having 80 mm and 60 mm sides. Drawing.

According to FIG. 10, when the spring (reaction action position) of the equivalent model is located in each corner of a flat plate, it shows that the position (reaction force measuring point) which measures the displacement of a flat plate is variously set. That is, in the case of ①, the reaction force measurement point is the same as the spring position, in the case of ②, the reaction force measurement point is the center of each side of the plate, and in the case of ③, the reaction force measurement point is 10mm away from the edge and the edge of the plate. In the case of ④, the reaction force measurement point is 10 mm away from the center of each side of the plate.

In this case, each parameter is determined as follows.

That is, L ₁ = 30, L ₂ = 40, L ₁ = 30, L ₂ = 40, F = 1, x = 10, y = 5, and A = -1/640, B = -1/270 , D = -0.25.

In this case, the measurement results for each case are shown in the following table.

Measurement result in the case of ① Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 -30 0.270833 10.83333 -8.125 40 30 0.354167 14.16667 10.625 -40 30 0.229167 -9.16667 6.875 -40 -30 00145833 -5.83333 -4.375 One Σx _i R _i = 10 ΣyiRi = 5

Measurement result in case of ② Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 0 0.3125 12.5 0 0 30 0.291667 0 8.75 -40 0 0.1875 -7.5 0 0 -30 0.208333 0 -6.25 One 5 2.5

Measurement result in case of ③ Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 -30 0.331967 13.27869 -9.95902 30 30 0.397541 11.92623 11.92623 -40 30 0.168033 -6.72131 5.040984 -30 -30 0.102459 -3.07377 -3.07377 One 15.40984 3.934426

Measurement result in the case of ④ Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 -10 0.364754 14.59016 -3.64754 10 30 0.331697 3.319672 9.959016 -40 10 0.135246 -5.40984 1.352459 -10 -30 0.168033 -1.68033 -5.04098 One 10.81697 2.622951

As a result of the measurement, in the case of measuring the position (x, y) for pressing by measuring the displacement of various positions while the spring is located at each corner of the rectangular plate, the position (x, y) in the case of ① and ② ), But in the case of ③ and ④, it was determined that a certain relation could not be obtained and thus the position of the push could not be obtained.

(3) In the case of rectangular flat plate, the reaction force is far from each corner

Fig. 11 shows the detection of the position (x, y) of the pressing by the displacement measured at each side when the pressing of the magnitude of the force acts on a rectangular flat plate of another equivalent model with each side having 80 mm and 60 mm. It is a figure for demonstrating a process.

According to FIG. 11, the position (reaction measuring point) which measures the displacement of a plate when the spring (reaction action position) of the equivalent model is located in the predetermined distance (for example, 25 mm) from the center of each side of a plate. ) Shows various settings. That is, in the case of ①, the reaction force measurement point is the same as the spring position, in the case of ②, the reaction force measurement point is the center of each side of the plate, and in the case of ③, the reaction force measurement point is each corner of the plate. The case shows that the reaction force measurement point is 10 mm away from the center of each side of the plate.

In this case, each parameter is determined as follows.

That is, L ₁ = 30, L ₂ = 40, L ₁ = 25, L ₂ = 25, F = 1, x = 10, y = 5, and A = -66/26645, B = -109/53290 , D = -0.25.

In this case, the measurement results for each case are shown in the following table.

Measurement result in the case of ① Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 -25 0.297945 11.91781 -7.44863 25 30 0.373288 9.332192 11.19863 -40 25 0.202055 -8.08219 5.05137 -25 -30 0.126712 -3.16781 -3.80137 One Σx _i R _i = 10 ΣyiRi = 5

Measurement result in case of ② Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 0 0.349081 13.96322 0 0 30 0.311362 0 9.340871 -40 0 0.150919 -6.03678 0 0 -30 0.188638 0 -5.65913 One 7.92644 3.681741

Measurement result in case of ③ Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 -30 0.287718 11.50873 -8.63154 30 30 0.385673 11.57018 11.57018 -40 30 0.212282 -8.49127 6.368456 -30 -30 0.114327 -3.42982 -3.42982 One 11.15782 5.877275

Measurement result in the case of ④ Reaction force point coordinates Deflection Z _i or reaction force R _i x _i R _i or x _i Z _i y _i R _i or yZ _i x _i y _i 40 -10 0.328626 13.14506 -3.28626 10 30 0.336132 3.361325 10.08397 -40 10 0.171374 -6085494 1.713736 -10 -30 0.163868 -1.63868 -4.91603 One 8.01276 3.595421

Looking at the measurement results, it can be seen that the calculation of the position (x, y) of the pressing can only be calculated in the case of ① where the reaction force measurement point is the same as the reaction force position.

Using the measurement results as described above, the shape of the flat plate, the position of the equivalent spring, and the reaction force measurement position can be set appropriately and applied to detecting the position of the pressing.

In addition, since ΣR _i = F, the intensity F of the pressing can also be measured by using the sum of the respective reaction forces.

Next, referring to FIGS. 12 to 15, an arrangement of electrodes for sensing capacitance in a touch panel according to an embodiment of the present invention will be described.

FIG. 12 is a cutout portion 14 that is cut off while forming the support portion 12 with a predetermined width from one side of a rectangular flat plate spring 10 according to an embodiment of the present invention as shown in FIG. And in the structure in which the connection part 16 was formed, it is a figure which shows each structure separately.

Referring to FIG. 12, the touch panel 100 includes a transparent plate 18B, a flat plate spring 10, a spacer 20, and a PCB substrate 30 positioned from the top, and a display device 70 at the bottom thereof. Is arranged. In this case, it may be confirmed that the light transmitting part 18A is formed at the center of the flat plate spring 10 and the PCB substrate 30 of the touch panel 100 so as to transmit the display screen of the display device 70.

FIG. 13 is a side view of a touch panel having the structure as shown in FIG. 12. Referring to the drawings, the respective components are bonded to each other up and down, in particular, the PCB substrate 30 is conductive to a portion opposite to the pressing portion (particularly, the portion corresponding to the transparent plate) 18 of the flat plate spring 10. It can be seen that the electrode 32 forming the capacitance with the flat plate spring 10 made of material is disposed.

FIG. 14 is a view for explaining a structure of detecting capacitance between the flat spring of the conductive material and the electrode of the PCB substrate. That is, the plate spring 10 and the electrode 32 are separated by the distance d by the spacer 20, and one side of the plate spring 10 and the electrode 32 are grounded and coordinate measuring units 40, respectively. Connected with. The coordinate measuring unit 40 measures and analyzes the capacitance at the electrode 32 in the MPU having the capacitance measuring function, thereby detecting whether the pressing, the position, the intensity, etc. occurred on the transparent plate 18B. do.

(여기에서, C 는 정전 용량, ε는 유전율, A는 전극의 면적, d는 전극 사이의 거리)의 관계를 얻을 수 있다. 이때, 좌표 측정부(40)에서 정전 용량(C)의 크기를 정전 용량 측정 기능을 구비한 MPU를 통해 측정하고, 측정된 정전 용량(C)에 기초하여 전극 사이의 거리(d)를 산출할 수 있고, 산출된 거리(d)에 의해 처짐양 Z₁,Z₂,Z₃,Z₄를 검출할 수 있게 된다. That is, depending on the distance and area between the two electrodes,

Where C is the capacitance, ε is the dielectric constant, A is the area of the electrode, and d is the distance between the electrodes. In this case, the coordinate measuring unit 40 measures the magnitude of the capacitance C through an MPU having a capacitance measurement function, and calculates the distance d between the electrodes based on the measured capacitance C. The deflection amount Z ₁ , Z ₂ , Z ₃ , Z ₄ can be detected by the calculated distance d.

The area A of the electrode may be applied in various shapes and sizes as shown in FIGS. 15A to 15C. 15 is a view illustrating various examples of the size and shape of electrodes disposed on a PCB substrate.

15 (a) shows a PCB substrate 30 having a size substantially the same as (or larger than) the appearance of the flat plate spring 10, the portion indicated by the dotted line corresponds to the support 12 of the flat plate spring 10. This is the position where the spacer 20 will be arranged later. In the central portion of the PCB substrate 30 is formed an empty space for light transmission. The electrode 32 is disposed between the empty space and the boundary for the support 12, and has a rectangular electrode as shown in FIGS. 15 (a) and 15 (b) or a circular electrode as shown in FIG. 15 (c). And may be arranged in various shapes and sizes.

16 is a view for explaining a structure in the touch panel according to the present invention, the transparent plate can be designed to the same size as the outer appearance of the flat spring. In FIG. 16A, the transparent plate 18B has the same size (or may be made larger) as the outer shape of the flat plate 10, and the transparent plate 18B has a spacer ( It is fixed using 22). 16B is a cross-sectional view of the touch panel having such a structure. With reference to this figure, the state in which the spacer 22 is arrange | positioned between the transparent plate 18B and the flat plate spring 10 can be confirmed more clearly.

In addition, as shown in Fig. 16B, the distance between the transparent plate 18B and the flat plate spring 10 is referred to as d ₁ , and the distance between the flat plate spring 10 and the PCB substrate 30 is referred to as d ₂ . At this time, by designing in a relationship of d ₁ <d _2, the transparent plate 18B first comes into contact with the flat plate spring 10 before the flat plate spring 10 directly contacts the electrode 32, thereby being excessively pressed. You can give a stopper function to. Therefore, the flat spring 10 is in direct contact with the electrode 32 to prevent an error that may occur electrically.

17 is a view for explaining another structure for fixing the flat plate spring. Referring to FIG. 17A, it can be seen that a base 60 having a protruding portion of a constant height is added. Base 60 may be applied to PCB substrate 30 in the structures described above.

The flat plate spring 10 is attached to and fixed to the protruding portion of the base 60. At this time, the flat plate spring 10 is not fixed to the support 12 in the structures described above, but to the inner portion of the incision 14 from the support 12. The transparent plate 18B is fixed on the support part 12. Therefore, deflection (displacement) occurs in the outer part (the part corresponding to the previous supporting part) with respect to the pressing against the transparent plate 18B.

18 is a view illustrating a shape of a flat spring having cutouts and connections having various structures in the touch panel according to the present invention.

18 (a) to 18 (d) have been described above. FIG. 18 (e) shows the connection part 16 formed in the center part of each side of the press part 18, and the incision part 14 is formed from this connection part 16 to both sides of the flat spring 10. FIG. It shows the structure.

Meanwhile, in the touch panel 100 according to the present invention, the support part 12 may be formed in a form that is firmly fixed to the PCB substrate 30 by the spacer 20, or the support part 12 may be curved or freely moved. It is also possible to configure so that.

19 is a view for explaining the form of the transparent plate and the various forms of the electrode or electrode pattern. 19 (a) shows a cross section of a shape in which the transparent plate 18B is formed to correspond to the size of the pressing portion 18 of the flat spring 10. In this manner, the electrode 32 is disposed at the position corresponding to the size of the transparent plate 18B on the PCB substrate 30. The capacitance is measured between the flat spring 10 and the electrode 32.

FIG. 19 (b) is a cross section in the case where a base is provided as in FIG. In this manner, since the transparent plate 18B can be formed to be larger than or equal to the outline of the flat spring 10, the electrode pattern 34 can be formed on the transparent plate 18B. The electrode 32 corresponding to the electrode pattern 34 formed on the transparent plate 18B may be formed on one side of the base 60, and the capacitance is measured between the electrode pattern 34 and the electrode 32.

FIG. 19 (c) is a cross section in the case where the transparent plate is fixed to the flat plate spring via a spacer as in FIG. 16. The electrode 32 is disposed at a portion of the PCB substrate 30 corresponding to the position of the pressing portion 18 of the flat plate spring 10, and the capacitance of the flat plate spring 10 and the electrode of the PCB board 30 ( Is measured between 32). In addition, when the transparent plate 18B is set equal to or larger than the outer shape of the flat spring 10, the transparent plate 18B may function as a stopper for limiting the pressing depth when the flat spring 10 is pressed too much.

The arrangement of the electrode 32 and / or the electrode pattern 34 may be applied to all the flat spring structures described above.

20 is a view for explaining various ways of coupling the flat plate spring and the PCB substrate. The flat plate spring 10 is mainly made of a conductive material to generate capacitance with the electrode 32 disposed on the PCB substrate 30. Therefore, it is preferable to be electrically connected to one side (mainly, ground) of the PCB substrate 30. For this reason, there is a need for a method that enables electrical connection in the coupling of the flat plate spring 10 and the PCB substrate 30.

FIG. 20A illustrates a spacer 20 disposed between the flat plate spring 10 and the PCB substrate 30 with a conductive material, and includes one surface of the flat plate spring 10 and the spacer 20 and a spacer ( The other side of 20) and the PCB substrate 30 are shown bonded together with a conductive adhesive. By this structure, an electrical connection may be made between the PCB substrate 30 and the flat plate spring 10.

FIG. 20 (b) shows an electrical connection by arranging spacers 20 between the flat plate spring 10 and the PCB substrate 30, forming communication holes therebetween, and injecting a conductive adhesive into the communication holes. Represents a structure. In this case, the spacer 20 may be a conductive material or an insulating material.

20 (c) shows a structure in which an electrical connection is made by performing screw coupling using a bolt of a conductive material to a communication hole in the structure of FIG. 20 (b).

FIG. 20 (d) attaches the flat plate spring 10, the spacer 20, and the PCB board 30 to each other by double-sided tape, and the electrical connection between the flat plate spring 10 and the PCB board 30 to a separate conductor. Show the form being done by

20 (e) does not form a separate spacer, but the flat plate spring 10 is connected to the solder joint in a state in which a part of the flat plate spring 10 is bent to have a constant height to perform the function of the spacer 20. It shows the form that is combined by According to such a structure, since a spacer does not need to be comprised separately, there exists a manufacturing advantage.

FIG. 20 (f) shows that a plurality of bent portions as shown in FIG. 20 (e) can be formed. On the other hand, the flat plate spring 10 and the PCB substrate 30 shows that it can be coupled by a bolt or the like.

FIG. 20 (g) shows a structure in which a spacer 20 disposed between the flat plate spring 10 and the PCB substrate 30 is formed by soldering.

FIG. 20 (h) shows a configuration in which the thick portion having a certain height is formed in the flat plate spring 10 to function as a spacer. At this time, the coupling between the flat plate spring 10 and the PCB substrate 30 may be applied to the various methods described above.

Such a coupling structure may be appropriately selected and applied as necessary.

According to the touch panel according to various embodiments of the present invention as described above, in the measurement of whether the pressing, the position of the pressing occurs, the intensity of the pressing using the capacitance, it is possible to use a spring in the form of a plate do. Therefore, the touch panel can be formed using a flat plate spring with a simple manufacturing method, and the touch position can be accurately detected using the capacitive method, so that the touch panel is simple, inexpensive, and highly accurate. It can be provided.

In addition, by forming a portion of the touch panel into an empty space, the display screen of the display device disposed behind the screen may be transmitted, and thus may be applied as a touch screen.

1 is a diagram illustrating a configuration of a touch panel according to an exemplary embodiment of the present invention.

2 is a view for analyzing the relationship between the force acting on the cantilever beam and the elastic deformation of the cantilever beam.

3 is a view showing an example of configuring a flat spring in the touch panel according to the present invention.

4 is a view showing another example of configuring a flat spring in the touch panel according to the present invention.

5 is a view showing another example of configuring a flat spring in the touch panel according to the present invention.

6 is a view showing still another example of configuring a flat spring in the touch panel according to the present invention.

FIG. 7 is a diagram in which respective parameters are set in order to analyze the relationship of displacement due to pressing in a flat spring having a structure as shown in FIG. 3.

8 is a view for explaining a process of detecting the position of the pressing by the displacement measured on each side in a square flat plate.

9 is a diagram for analyzing an actual measurement result.

FIG. 10 is a view for explaining a process of detecting the position of pressing in the rectangular flat plate by the displacement measured at each side. FIG.

11 is a view for explaining a process of detecting the position of the pressing by the displacement measured at each side in the rectangular flat plate of another equivalent spring model.

FIG. 12 is a view showing the respective components separately in the flat plate spring structure according to the embodiment of the present invention as shown in FIG.

FIG. 13 is a side view of a touch panel having the structure as shown in FIG. 12.

14 is a view for explaining a structure for detecting the capacitance between the flat plate spring and the PCB substrate.

15 is a view illustrating various examples of the size and shape of electrodes disposed on a PCB substrate.

16 is a view for explaining the structure of the touch panel according to an embodiment of the present invention.

17 is a view for explaining another structure for fixing the flat plate spring.

18 is a view illustrating a shape of a flat spring having cutouts and connections having various structures in the touch panel according to the present invention.

19 is a view for explaining the form of the transparent plate and the various forms of the electrode or electrode pattern.

20 is a view for explaining various ways of coupling the flat plate spring and the PCB substrate.

Claims (5)

A support portion corresponding to a circumferential portion of the plate, a plurality of incisions partially cut into the plate so as to form a boundary line between the support portion and an inner region of the support portion, and the incision at the boundary line A flat spring having a plurality of connecting portions corresponding to portions not cut by the portions, and pressing portions corresponding to the inner region of the support portion and pressed according to the user's pressing and restored by elasticity of the connecting portions; A PCB substrate having at least one electrode disposed at a position opposite to the pressing portion of the flat plate spring and arranged in parallel to the flat plate spring; A spacer disposed between the PCB substrate and the support portion such that the pressing portion of the flat plate spring and the at least one electrode of the PCB substrate maintain a constant distance from each other when there is no user press; A coordinate measuring unit configured to sense capacitance between the pressing unit and the at least one electrode, and determine at least one of pressing of the pressing unit, position of pressing, and intensity of pressing by the sensed capacitance Force-based capacitive touch panel, including. The method of claim 1, The flat plate spring further includes a light transmitting portion formed by removing the flat plate from a portion of the pressing portion, The light-emitting part is a power-based capacitive touch panel, characterized in that the transparent portion is formed on the transparent portion of the pressing portion is not removed the flat plate to cover the transparent portion. The method of claim 2, The floodlight panel is a force-based capacitive touch panel, characterized in that attached to the edge portion of the pressing portion via a spacer having a predetermined thickness. The method of claim 3, The floodlight panel is a force-based capacitive touch panel, characterized in that having a size larger than the outer shape of the pressing portion. The method of claim 2, An electrode pattern is formed on the floodlight plate so as to face each of the electrodes formed on the PCB substrate. The coordinate measuring unit is configured to determine at least one of the pressing of the pressing portion, the position of the pressing and the intensity of the pressing by the capacitance between the electrode of the PCB substrate and the electrode pattern of the floodlight plate. Capacitive touch panel.

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