Handwriting pen

Abstract

A stylus pen according to one embodiment includes: a main body; a tip exposed from the inside to the outside of the body; an inductor unit including a ferrite core disposed within the main body and a coil wound in multiple layers on at least a portion of the ferrite core; and a capacitor unit disposed within the body to be electrically connected to the inductor unit to form a resonant circuit, in which the ferrite core has a dielectric constant less than or equal to 1000 F / m, and in which the coil has a form in which adjacent winding layers are alternately wound, and the coil is an electric wire covering two or more insulated wires.

Description

[0001] This application is a divisional application. The application date of the parent application is February 14, 2020, the application number is 202080014569.7, and the name of the invention is “Handwriting Pen”. Technical Field

[0002] The invention relates to a stylus pen. Background Art

[0003] Various terminals such as mobile phones, smart phones, tablet computers, notebook computers, digital broadcast terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigators, etc. include touch sensors.

[0004] In such a terminal, the touch sensor may be arranged on a display panel displaying an image, or may be arranged in a region of a terminal body. When a user interacts with the terminal by touching the touch sensor, the terminal may provide an intuitive user interface to the user.

[0005] A user can use a stylus pen for complex touch input. Stylus pens can be classified into active stylus pens and passive stylus pens according to whether batteries and electronic components are provided therein.

[0006] Active styluses may have better basic performance and offer additional features (pen pressure, hover, and buttons) than passive styluses, but the pens themselves are expensive and require a power source to charge the battery, so they are not used by all but a few advanced users.

[0007] Compared to an active stylus, a passive stylus is cheap and does not require a battery, but touch recognition is difficult compared to an active stylus. However, recently, in order to realize a passive stylus capable of complex touch recognition, technologies of an inductive resonance type EMR (electromagnetic resonance) method and a capacitive resonance method have been proposed.

[0008] The EMR approach is superior in writing / drawing quality, a key feature of a stylus, but is thicker and more expensive because a separate EMR sensor panel and EMR driver IC must be added in addition to the capacitive touch panel.

[0009] The capacitive resonance method uses a general-purpose capacitive touch sensor and touch controller IC to support pen touch by improving the performance of the IC without additional cost.

[0010] In the capacitive resonance method, for the touch sensor to more accurately identify the touch of the stylus, the amplitude of the resonant signal must be large, so the frequency of the drive signal transmitted from the touch sensor to the stylus is almost equal to the resonant frequency of the resonant circuit built into the stylus. However, according to the conventional capacitive resonance method, even when the resonant frequency and the frequency of the drive signal coincide with each other, since the capacitance formed between the touch sensor outputting the drive signal and the pen tip receiving the drive signal is very small, the attenuation of the signal transmission becomes very large, making signal transmission difficult. Therefore, despite long-term attempts by many touch controller IC suppliers, no company has been able to successfully mass-produce because sufficient output signals have not been obtained.

[0011] Therefore, how to design the internal resonant circuit and pen structure is a very important factor in manufacturing a capacitive resonant stylus that can produce a maximum output signal. Summary of the invention

[0012] Technical issues

[0013] Exemplary embodiments of the present invention are directed to providing a capacitive resonance stylus pen capable of generating a sufficient output signal.

[0014] Technical Solution

[0015] In order to achieve the above purpose or other purposes, an exemplary embodiment of the present invention provides a stylus pen, including:

[0016] a body; a conductive tip configured to be exposed from the inside of the body to the outside of the body; an inductor unit including a ferrite core arranged in the body and a coil connected to the conductive tip and wound on at least a portion of the ferrite core in multiple layers; and a capacitor unit arranged in the body to be electrically connected to the inductor unit to form a resonant circuit.

[0017] Herein, the dielectric constant of the ferrite core may be less than or equal to 1000 F / m, and the coil has a form in which adjacent winding layers are alternately wound, and the coil is an electric wire covering two or more insulating wires.

[0018] Additionally, the ferrite core may include nickel, and the coil may be formed from litz wire.

[0019] The stylus may further include a ground that may be electrically connected to a user, the stylus may further include a bobbin surrounding at least a portion of the ferrite core, and the coil may be wound around at least a portion of the bobbin.

[0020] The stylus may further include a conductive preventing member configured to surround at least a portion of the resonant circuit. The preventing member may include a slit for preventing generation of eddy current, and opposite ends of the preventing member may be spaced apart by the slit in a first direction in which the eddy current is formed.

[0021] Another exemplary embodiment of the present invention provides a stylus pen, comprising: a main body; a conductive tip, the conductive tip being configured to be exposed from the inside of the main body to the outside of the main body; a resonant circuit, the resonant circuit being arranged in the main body to be connected to the conductive tip and to resonate an electrical signal transmitted from the conductive tip; and a ground portion, the ground portion being configured to be electrically connected to a user.

[0022] Herein, the resonant circuit may include: an inductor unit configured to include a ferrite core arranged in a body and a coil electrically connected to a conductive tip and wound on at least a portion of the ferrite core in multiple layers; and a capacitor unit arranged in the body to be electrically connected to a ground portion and the conductive tip. In this case, the dielectric constant of the ferrite core may be less than or equal to 1000 F / m, the coil is zigzag wound so that adjacent winding layers are inclined to each other, and the coil may be an electric wire covering two or more insulating wires.

[0023] Additionally, the ferrite core may include nickel, and the coil may be formed from litz wire.

[0024] In this case, the resonance circuit may be formed to include two or more inductor units and one capacitor unit connected in series. In addition, the resonance circuit may include two or more LC resonance circuits connected in series.

[0025] The stylus may further include a conductive preventing member configured to surround at least a portion of the resonant circuit. The preventing member may include a slit for preventing generation of eddy current, and opposite ends of the preventing member may be separated by the slit in a first direction in which the eddy current is formed.

[0026] Beneficial Effects

[0027] The effects of the stylus according to the present invention will be described below.

[0028] According to at least one exemplary embodiment of the present invention, by presenting the structure of the resonance circuit of the optimal capacitive resonance stylus, a sufficient output signal can be generated even if the diameter is thin.

[0029] According to at least one exemplary embodiment of the present invention, a stylus pen that is strong against external factors can be provided.

[0030] Other application scopes of the present invention will become apparent from the following detailed description. However, since those skilled in the art can fully appreciate various changes and modifications within the spirit and scope of the present invention, it can be understood that the detailed description and specific exemplary embodiments of the present invention are provided by way of example only. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram showing a stylus pen and a touch sensor.

[0032] Figure 2 The stylus and touch sensor are shown in detail.

[0033] Figure 3 The inductor unit of the stylus is shown in detail.

[0034] Figure 4 The inductance and Q value depending on the frequency variation are shown.

[0035] Figure 5 and Figure 6 Enameled wire and stranded wire are shown separately.

[0036] Figure 7 A multi-layer winding method is shown.

[0037] Figures 8 to 10 A graph comparing experimental results is shown.

[0038] Fig.11 Another example of an inductor unit is shown.

[0039] Fig.12 and Fig.13 is a graph showing the amplitude of a resonance signal depending on the structure of an inductor unit.

[0040] Fig.14 and Fig.15 Other examples of resonant circuits are shown.

[0041] Fig.16 is an equivalent circuit showing the effect of the parasitic capacitance of the user's hand.

[0042] Fig.17 is a schematic diagram of a stylus showing an LLC structure.

[0043] Fig.18 Various examples of preventing members are shown. DETAILED DESCRIPTION

[0044] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present invention are shown. As those skilled in the art will appreciate, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present invention.

[0045] In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals refer to the same or similar constituent elements throughout the specification.

[0046] In addition, unless explicitly described to the contrary, the word "comprise" and variations thereof (such as comprises or comprising) will be understood to mean including the stated elements without excluding any other elements. When a component is referred to as being "on" or "over" another component, it can be directly on or over the other component, or other components can be interposed therebetween. On the contrary, when a component is referred to as being "directly over" another component, there are no other components interposed therebetween.

[0047] Figure 1 is a schematic diagram showing a capacitive resonant stylus and a touch sensor. Figure 1 As shown, the stylus pen 10 and the touch sensor 20 may be close to each other.

[0048] The stylus pen 10 may include a conductive tip 11 , a resonant circuit 12 , a ground portion 18 , and a body 19 .

[0049] The conductive tip 11 is connected to the resonant circuit 12. All or part of the conductive tip 11 may be formed of a conductive material (e.g., metal, graphite, conductive rubber, conductive fabric, conductive silicone, etc.). In addition, the conductive tip 11 may have the following form: the conductive tip 11 is arranged inside the non-conductive housing, and a part is exposed to the outside of the non-conductive housing, but is not limited thereto.

[0050] The resonant circuit 12 may generate resonance using a driving signal input from the touch sensor 20. For example, the resonant circuit 12 may be an LC resonant circuit, and may generate resonance using a driving signal received from the touch sensor 20 through the conductive tip 11. The driving signal may be a Tx signal transmitted to the touch electrode (channel). For example, the driving signal may include a signal (e.g., a sine wave, a square wave, etc.) having a frequency corresponding to the resonant frequency of the stylus pen 10, so as to allow the stylus pen 10 to generate a resonant signal through capacitive coupling or electromagnetic resonance.

[0051] The resonant circuit 12 can output a resonant signal generated by resonance to the conductive tip 11 during a time period when the driving signal is input and during a partial time period thereafter. The resonant circuit 12 is arranged in the body 19 to be connected to the ground portion 18. The ground portion 18 can be grounded by the body of a user contacting the outer surface of the body 19.

[0052] The body 19 can house the components of the stylus 10. Figure 1 In the figure, the main body 19 is shown in the form of a horn part and a column part integrated, but these two parts can be separated. The main body 19 can have a cylindrical shape, a polygonal shape, a cylindrical shape with at least a portion of a curved surface shape, a convex belly shape, a truncated cone shape, a truncated cone shape, etc., but is not limited thereto. Since the inside of the main body 19 is hollow, the main body 19 can accommodate the conductive tip 11, the resonant circuit 12 and the grounding part 18 therein.

[0053] The touch sensor 20 may include a channel electrode 21 and a window 22 disposed at an upper portion of the channel electrode 21. The channel electrode 21, the conductive tip 11, and the window 22 may constitute a capacitor Cx.

[0054] Figure 2 is a schematic diagram showing a stylus pen and a touch sensor in detail.

[0055] First, if Figure 2 As shown, the stylus pen 10 includes a conductive tip 11, a capacitor unit 13, an inductor unit 14, a grounding portion 18, and a body 19. The capacitor unit 13 and the inductor unit 14 constitute Figure 1 The resonant circuit 12.

[0056] The conductive tip 11 may be connected to the capacitor unit 13 and / or the inductor unit 14 by a conductive connection member, which may be a wire, a pin, a rod, a bar, etc., but is not limited thereto. In addition, the conductive connection member may include a coil of the inductor unit 14.

[0057] The capacitor unit 13 may include a plurality of capacitors connected in parallel. The capacitors may have different capacitances and may be trimmed during the manufacturing process.

[0058] The inductor unit 14 may be arranged adjacent to the conductive tip 11. The inductor unit 14 includes a ferrite core and a coil wound around the ferrite core.

[0059] The capacitor unit 13 and the inductor unit 14 are connected in parallel, and a resonance signal is generated by LC resonance of the capacitor unit 13 and the inductor unit 14 in response to a driving signal. Figure 3 is a schematic diagram showing in detail an inductor unit of the stylus.

[0060] refer to Figure 3, the inductor unit 14 includes a ferrite core 15 and a coil 16 wound around the ferrite core 15 .

[0061] In this case, the inductance of the inductor unit 14 is determined by the following Equation 1.

[0062] (Equation 1)

[0063]

[0064] As can be seen from Equation 1, the inductance is proportional to the magnetic permeability of the ferrite core 15 , the cross-sectional area of ​​the coil 16 , and the square of the number of turns, and is inversely proportional to the winding length of the coil 16 .

[0065] In the resonant circuit 12 contained in the capacitive resonant stylus, the design of the inductor unit 14 is very important. In particular, in the design of the inductor unit, the inductance L and the Q value are very important parameters, such as Figure 4 As shown. In this article, the Q value is a quantity representing the characteristics of a coil as a resonant circuit element, and is given by the equation Q = 2πfL / R. In addition, L and R represent the inductance and resistance of the coil, respectively, and f represents the frequency. The higher the Q value, the more severe the resonant characteristics.

[0066] In the design of a capacitive resonant stylus, L can have a sufficiently large self-resonant frequency relative to the frequency to be used, and the Q value can have a maximum value at the frequency to be used. To meet this, it is necessary to optimize the material of the ferrite core, the wire type of the coil, and the winding scheme. A method is also required that can obtain a high output signal while maintaining the diameter of a thin stylus.

[0067] In the following exemplary embodiments, a design method of a capacitive resonance stylus optimized among materials of a plurality of ferrite cores, wire types of coils, and winding schemes will be described.

[0068] 1. Ferrite core material

[0069] In one example, manganese (Mn) and nickel (Ni) are used as ferrite core materials.

[0070] 2. Line type

[0071] In this example, enameled wire and litz wire are used as the wire types of the coil used.

[0072] like Figure 5 As shown, the enameled wire 100 is an electric wire made by coating an insulating varnish 102 on the surface of a copper wire 101 and heating it to a high temperature, and is used for winding and wiring of electrical equipment, communication equipment, and electrical instruments. In this example, an enameled wire with a total thickness T of 0.2 mm, a wire diameter Φ of 0.18 mm, and a coating thickness t of 0.01 mm is used.

[0073] like Figure 6 As shown, the twisted wire 200 is a special insulated wire made by twisting a plurality of strands of a thin insulated wire 100 (e.g., enameled wire) having a diameter of about 0.1 mm into one wire and applying an insulating coating 201 made of nylon, etc. The twisted wire 200 can reduce the skin effect by increasing the surface area and is used for coils of high-frequency circuits, etc.

[0074] In this example, a stranded wire having a total thickness T of 0.2 mm, a wire diameter Φ of 0.06 mm, and a cover thickness t of 0.007 mm is used.

[0075] 3. Winding scheme

[0076] In the example of the present invention, in order to obtain a sufficient inductance value (i.e., a sufficient number of turns) within the limited space of the stylus, a winding scheme of a multi-layer winding structure is used. Figure 7 As shown in (A) and (B), two multi-layer winding schemes are used.

[0077] Figure 7 The winding scheme of (A) is the simplest winding scheme, which is a sequential layered winding scheme in which the upper layer is wound after the winding of the lower layer arranged immediately below it is finished. In this case, Figure 7 The scheme of (A) is a scheme in which the winding of one layer starts from a point where the winding of the previous layer arranged immediately below it ends, and is hereinafter referred to as a U-type winding scheme.

[0078] Figure 7 The winding scheme of (B) is an alternating layer winding scheme, in which adjacent winding layers are alternately wound so that the windings of adjacent layers are wound in a zigzag shape. Hereinafter, this is referred to as a zigzag winding scheme. This zigzag winding scheme can minimize the voltage difference between the windings of adjacent layers, thereby reducing the winding self-capacitance. In this case, the winding self-capacitance, which is a parasitic capacitance, is a parameter representing the electric field energy stored in the winding.

[0079] Comparative experiment 1 (comparison of characteristic values ​​of each material)

[0080] The ferrite core material was changed to manganese, nickel, and magnesium, and the Q value was measured in a state where an enameled wire was used as the wire type of the coil and was wound in a U-type winding scheme.

[0081] As a result of the measurement, there was almost no difference in the characteristics of the Q value of the magnetic core of each material, and the measured Q value was not sufficient to be implemented as a product.

[0082] Comparative experiment 2 (Comparison of characteristic values ​​of various types of windings)

[0083] The Q values ​​were respectively measured for the inductors 1 and 2 manufactured using the enameled wire and the stranded wire in a state where the ferrite core was wound with manganese (Mn) through a U-type winding scheme.

[0084] Figure 8 Shown are the Q values ​​of inductors 1 and 2 measured by an E4980A precision LCR meter manufactured by KEYSIGHT TECHNOLOGIES while varying the frequency.

[0085] exist Figure 8 In the figure, a is a waveform showing the change of Q value relative to the frequency of inductor 1 (manganese core / enamel wire / U-type winding scheme), and b is a waveform showing the change of Q value relative to the frequency of inductor 2 (manganese core / litter wire / U-type winding scheme).

[0086] In the inductor 2 made of stranded wire, the Q value has almost a maximum value at a frequency of about 400 kHz (frequency f1), whereas in the inductor 1 made of enameled wire, the Q value has almost a maximum value at a frequency of about 150 kHz (frequency f2).

[0087] As Figure 8 Comparing the results of a and b, it can be seen that the maximum Q value of inductor 2 is about 1.5 times higher than the maximum Q value of inductor 1. Therefore, it can be seen that as a coil of the inductor forming the resonant circuit of the stylus, the stranded wire is superior to the enameled wire.

[0088] However, the maximum Q value of inductor 2 measured in comparative experiment 2 is approximately the target value Q required for commercialization. target 1 / 2 of.

[0089] Comparative experiment 3 (Comparison of characteristic values ​​of various winding schemes)

[0090] In a state where the ferrite core is made of manganese (Mn), the Q value was measured for inductors 3 to 5 manufactured by changing the wire type to an enameled wire and a stranded wire and changing the winding scheme to a U type and a Z type.

[0091] Fig. 9 Shown are the Q values ​​of inductors 3 to 5 measured while changing the frequency by an E4980A precision LCR meter manufactured by KEYSIGHT TECHNOLOGIES.

[0092] exist Fig. 9 Among them, a is a waveform showing the change of Q value relative to the frequency of inductor 3 (manganese core / enamel wire / U-type winding scheme), b is a waveform showing the change of Q value relative to the frequency of inductor 4 (manganese core / enamel wire / Z-type winding scheme), and c is a waveform showing the change of Q value relative to the frequency of inductor 5 (manganese core / twisted wire / Z-type winding scheme).

[0093] As from Fig. 9 It can be seen from the waveform c that in the inductor 5 manufactured by the twisted wire / zigzag winding scheme, the Q value has almost a maximum value at a frequency of about 300kHz (frequency f3). In the inductor 4 manufactured by the enameled wire / zigzag winding scheme and the inductor 3 manufactured by the enameled wire / U-type winding scheme, the Q value has almost a maximum value at a frequency of about 150kHz (frequency f2).

[0094] In addition, as Fig. 9 From the comparison results of a, b, and c, it can be seen that the maximum Q value of inductor 5 is about 1.5 times higher than the maximum Q value of inductor 4, and twice or more higher than the maximum Q value of inductor 3. Therefore, it can be seen that as a winding scheme of the inductor forming the resonant circuit of the stylus pen, the Z-type is superior to the U-type.

[0095] However, the maximum Q value of inductor 5 (manganese core / litter wire / zigzag winding scheme) measured in comparative experiment 2 is approximately the target value Q required for commercialization. target 3 / 4 of.

[0096] Comparative Experiment 4 (Comparison of characteristic values ​​of various core materials)

[0097] In this example, manganese and nickel are used as the ferrite core materials, and it is known that the magnetic permeability of nickel is generally 200-300, and the magnetic permeability of manganese is generally 3000-5000.

[0098] Since the magnetic permeability of manganese used in this example is about 15 times higher than that of nickel, assuming the coils have the same cross-sectional area and length, the number of turns of nickel is about four times that of manganese to obtain the same inductance value. Therefore, from the perspective of the number of turns alone, it can be seen that using manganese is more efficient than using nickel.

[0099] On the other hand, since the inductor unit 14 has a complicated structure including a coil wound around a magnetic core, parasitic capacitance is additionally generated. Since the Q value is reduced due to such parasitic capacitance, the amplitude of the resonance signal may be reduced.

[0100] Parasitic capacitance generated in the inductor unit 14 may occur between the wound coils and between the magnetic core and the coils, and as described above, the parasitic capacitance between the wound coils may be reduced by adopting the zigzag winding scheme.

[0101] Meanwhile, in this example, in order to reduce the parasitic capacitance between the core and the coil, a core material having a lower dielectric constant than manganese was tested, and the test results confirmed that the nickel core was the best material for the ferrite core.

[0102] The important physical property of manganese and nickel, which are mainly used as ferrite core components, is the magnetic permeability, which has a significant impact on the inductance value, as shown in Equation 1. However, in manganese and nickel as ferrite components, the dielectric constant is a less concerned physical property, in fact, nickel does not have relevant information in the data sheet provided by the manufacturer.

[0103] In this example, in order to confirm the dielectric constants of manganese and nickel, the dielectric constants of manganese and nickel were measured using KEYSIGHT TECHNOLOGIES' E4980A precision LCR meter, and the measurement results are shown in Table 1 below.

[0104] (Table 1)

[0105] Dielectric constant of manganese Dielectric constant of manganese Measurement 1 2400 - Measurement 2 8300 2

[0106] Measurements 1 and 2 were measured using the same E4980A precision LCR meter from KEYSIGHT TECHNOLOGIES, where measurement 1 represents the dielectric constant automatically calculated by the measurement software. According to measurement 1, although the dielectric constant of manganese is 2400, the dielectric constant of nickel is not measured.

[0107] Measurement 2 is a method of calculating the dielectric constant by measuring capacitance, area, and distance between ferrite cores, and according to Measurement 2, the dielectric constant of manganese is 8300 and the dielectric constant of nickel is 2.

[0108] There is a large difference in the dielectric constant results between Measurement 1 and Measurement 2, and in the case of Measurement 2, it is confirmed that the error is considerable depending on the capacitance, area, distance, etc. However, as a result of Measurement 1 and Measurement 2, it can be seen that the dielectric constant of nickel is at least 1 / 1000 or more of that of manganese.

[0109] In Comparative Experiment 4, the Q value was measured for inductors 6 and 7 manufactured by changing the winding type to a U-type and a Z-type having a ferrite core made of nickel and using a litz wire as a wire type.

[0110] Fig.10 The Q values ​​of inductors 6 and 7 measured while changing the frequency by an E4980A precision LCR meter manufactured by KEYSIGHT TECHNOLOGIES are shown.

[0111] exist Fig.10 In the figure, a is a waveform showing the change of Q value relative to the frequency of inductor 6 (nickel core / twisted wire / U-shaped winding scheme), and b is a waveform showing the change of Q value relative to the frequency of inductor 7 (nickel core / twisted wire / Z-shaped winding scheme).

[0112] from Fig.10It can be seen from waveform b that in inductor 7 manufactured by the nickel core / litter wire / zigzag winding scheme, the Q value has almost a maximum value at a frequency of about 400kHz (frequency f5). In inductor 6 manufactured by the nickel core / litter wire / U-shaped winding scheme, the Q value has almost a maximum value at a frequency of about 200kHz (frequency f6). Fig.11 From the comparison results of a and b, it can be seen that the maximum Q value of inductor 7 is about twice as high as the maximum Q value of inductor 6.

[0113] The maximum Q value of inductor 7 (nickel core / litter wire / zigzag winding scheme) measured in comparison experiment 4 almost reaches the target value Q required for commercialization. target .

[0114] In the above-mentioned comparative experiments 1 to 4, the Q value of the inductor was manufactured and tested by changing the material of the ferrite core, the wire type of the coil, and the winding scheme. The test results show that the highest Q value is obtained when the inductor unit of the capacitive resonant stylus is designed by winding a nickel core, a stranded wire, and a zigzag winding scheme. In addition, it can be seen that the maximum Q value of the inductor manufactured by this combination reaches the target value Q for commercialization. target .

[0115] Meanwhile, in the present exemplary embodiment, a nickel core is used as the ferrite core and a stranded wire is used as the wire type of the core, but similar results can be obtained when a material having a dielectric constant less than or equal to 1000 is used instead of the nickel core as the ferrite core, and a single wire wrapped with two or more insulating strands is used instead of the stranded wire.

[0116] In the present exemplary embodiment, as described below, in addition to using nickel having a lower dielectric constant than manganese, a method of increasing the distance between the core and the coil by providing a bobbin between the core and the coil may be used to further reduce the parasitic capacitance between the core and the coil.

[0117] refer to Fig.11 , the inductor unit 14 includes a ferrite core 15, a bobbin 141 surrounding at least a portion of the ferrite core 15, and a coil 16 wound on at least a portion of the bobbin 141. The bobbin 141 can be fixed by being tightly attached to the ferrite core 15 by the force generated by the winding of the coil 16. The bobbin 141 may include the same material as that of the body 19 or a different material, and may include, for example, plastic or metal having an insulating surface. Specifically, polyphenylene sulfide (PPS), liquid crystal polyester (LCP), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), phenolic resin, etc. can be used for the bobbin 141.

[0118] As such, when the bobbin 141 covers the ferrite core 15 and the bobbin 141 is wound around the coil 16, the distance between the ferrite core 15 and the coil 16 increases, thereby Fig.11 The value of the parasitic capacitance Cp2 in can be set to be less than Figure 3 The value of the parasitic capacitance Cp1 in.

[0119] refer to Fig.12 , when the inductor unit 14 includes only the ferrite core 15 and the coil 16, the maximum amplitude of the measured resonant signal is about 2V (+1V to -1V). Fig.13 , when the inductor unit 14 includes the ferrite core 15, the bobbin 141 and the coil 16, the maximum amplitude of the measured resonance signal is about 4V (+2V to -2V). That is, when at least a portion of the ferrite core 15 is enclosed in the bobbin 141 and the coil 16 is wound on the bobbin 141, it is confirmed that the amplitude of the resonance signal is larger.

[0120] Meanwhile, in the case of designing the optimal inductor unit according to the present exemplary embodiment using nickel as the ferrite core, as described above, nickel has a magnetic permeability 1 / 15 times lower than that of manganese, so the number of turns of nickel must be increased to about four times that of manganese to achieve the same inductance. Therefore, the diameter of nickel must be larger than that of manganese to obtain the same inductance as that of manganese.

[0121] In the present exemplary embodiment, a method of using a plurality of inductors is proposed to achieve a high output signal while reducing the diameter of the stylus pen.

[0122] Fig.14 An equivalent circuit is shown in which two thin-diameter inductors are connected in series and a capacitor is connected in parallel between opposite ends of the two inductors. Hereinafter, this type of resonant circuit is referred to as an "LLC resonant circuit". Fig.14 In the example, two inductors are shown to be connected in series, but the exemplary embodiment is not limited thereto, and three or more inductors may be connected in series. According to the LLC resonant circuit, since the inductance L is twice as large as the inductance of a resonant circuit having one inductor and a capacitor (hereinafter referred to as an "LC resonant circuit"), the capacitance can be reduced to half. That is, the LLC resonant circuit can be made thinner than the LC resonant circuit, but is more sensitive to the influence of the capacitance.

[0123] at the same time, Fig.15 An equivalent circuit is shown in which two LC resonant circuits are connected in series (hereinafter referred to as "LCLC resonant circuit"), in which two resonant signals are combined and output. Fig.15 In FIG. 1 , it is shown that two LC resonance circuits are connected in series, but the exemplary embodiment is not limited thereto, and three or more LC resonance circuits may be connected in series.

[0124] According to the LCLC resonant circuit, since the resonant frequencies of the two resonant circuits must be the same, the resonant frequency of each resonant circuit must be tuned to be the same during the manufacturing process.

[0125] As described above, although the number of windings generated by using nickel as the ferrite core increases, when Fig.14 and Fig.15 When two or more inductors are used as shown, a stylus pen having a thin diameter can be manufactured by suppressing an increase in the diameter of the inductor unit.

[0126] At the same time, if Fig.14 As shown, when an LLC resonant circuit is used, a stylus having a structure described below can be adopted to minimize the effect of the capacitance reduced by half.

[0127] exist Figure 2 In the embodiment, the stylus pen 10 is held by a user's finger or the like, in which case the parasitic capacitance Cf may be formed by the finger and an internal conductor (coil or capacitor) of the stylus pen 1 .

[0128] Fig.16 An equivalent circuit is shown which illustrates the effect of the user's hand on the parasitic capacitance Cf. Fig.16 , the resonant frequency of the stylus pen 10 is changed by the parasitic capacitance Cf (40). As a result, the frequency of the drive signal 30 and the resonant frequency of the stylus pen 10 are inconsistent, and thus the amplitude of the signal output from the stylus pen 10 is reduced. In this case, the influence of the parasitic capacitance Cf (40) is Fig.14 The LLC circuit shown is larger than the LC resonant circuit or the LCLC resonant circuit. This is because when the same resonant frequency is designed, the capacitance of the LLC resonant circuit is 1 / 2 of the capacitance of the LC resonant circuit or the LCLC resonant circuit.

[0129] In the following, reference will be made to Fig.17 A stylus for preventing a resonant frequency from changing due to a user's grip is described.

[0130] Fig.17 is a schematic diagram of a stylus pen showing the LLC structure.

[0131] like Fig.17 As shown, the stylus pen 10 includes a conductive tip 11 , a capacitor unit 13 , two inductor units 14 and 14 ′, a blocking member 17 , a ground portion 18 , and a body 19 .

[0132] The inductor units 14 and 14' include ferrite cores 15 and 15' and coils 16 and 16' wound around the ferrite cores 15 and 15', respectively. In this case, the two inductor units 14 and 14' are connected in series.

[0133] The preventing member 17 is a conductive member surrounding the capacitor unit 13 and the inductor units 14 and 14 ′, and can prevent parasitic capacitance from being generated by the user's hand.

[0134] In this case, the preventing member 17 may be designed such that opposite ends of the preventing member 17 may be spaced apart along the direction ED of the eddy current to minimize the influence of the eddy current generated in the stylus.

[0135] In this regard, reference will be made to Fig.18 (a) to (d) describe the preventing member 17 in detail.

[0136] like Fig.17 As shown, a clockwise current flows through the coils 16 and 16' by a driving signal transmitted from the conductive tip 11, and a magnetic field is generated by the current flowing through the coils 16 and 16'. In this case, an eddy current is generated in a counterclockwise direction opposite to the current direction of the coil by a change in the magnetic field generated by the current of the coil, and thus an eddy current in the counterclockwise direction flows in the blocking member 17.

[0137] refer to Fig.18 (a), the preventing member 17 includes a slit GP for preventing the generation of eddy current. The slit GP is along the eddy current ( Fig.18 The opposite ends 17a and 17b of the blocking member 17 are separated by a slit GP. In an exemplary embodiment, the width of the slit GP along the direction ED of the eddy current may be greater than or equal to 0.03 mm.

[0138] Although the slit GP has been described as extending in the direction PD perpendicular to the eddy current, the slit GP may also extend in a direction inclined at a predetermined angle (greater than 0 degrees and less than 90 degrees) relative to the direction PD. The opposite ends 17a and 17b of the prevention member 17 are spaced apart in the direction ED of the eddy current. Since the eddy current cannot flow along the prevention member 17, the generation of the eddy current is interrupted.

[0139] refer to Fig.18 (b), the preventing member 17 includes a plurality of first preventing units 171. These first preventing units 171 extend along a direction PD perpendicular to the eddy current and are spaced apart from each other along the direction ED of the eddy current. Similarly, since the preventing member 17 includes a plurality of first preventing units 171 spaced apart from each other along the direction ED of the eddy current, no eddy current can flow along the preventing member 17, thereby preventing the generation of eddy current. Although the first preventing unit 171 has been described as extending along the direction PD perpendicular to the eddy current, the first preventing unit 171 may also extend in a direction inclined at a predetermined angle (greater than 0 degrees and less than 90 degrees) relative to the direction PD.

[0140] refer to Fig.18 (c), the preventing member 17 includes a plurality of second preventing units 172. These second preventing units 172 are spaced apart in a direction PD perpendicular to the eddy current, and opposite ends of each second preventing unit 172 are spaced apart from each other in the direction ED of the eddy current. Similarly, since opposite ends of each second preventing unit 172 included in the preventing member 17 are spaced apart in the direction ED of the eddy current, no eddy current can flow along the preventing member 17, thereby preventing the generation of the eddy current.

[0141] refer to Fig.18 (d), the preventing member 17 includes a plurality of third preventing units 173. These third preventing units 173 are spaced apart from each other in the direction PD perpendicular to the eddy current and in the direction ED of the eddy current. Similarly, since the third preventing units 173 included in the preventing member 17 are spaced apart in the direction ED of the eddy current, no eddy current can flow along the preventing member 17, thereby preventing the generation of the eddy current.

[0142] Although the exemplary embodiments of the present invention have been described above, the above detailed description should not be interpreted as limiting in all aspects, but should be considered as exemplary. The scope of the present invention should be determined by the reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

[0143] Description of Reference Numerals

[0144] 10 stylus, 11 conductive tip, 12 resonant circuit, 13 capacitor unit

[0145] 14 inductor unit, 15 ferrite core, 16 coil, 17 blocking member, 18 grounding portion

[0146] 19 main body, 20 touch sensor, 30 driving signal, 40 parasitic capacitance, 100 enameled wire

[0147] 101 copper wire, 102 insulating varnish, 141 bobbin, 200 stranded wire, 201 insulating coating

Claims

1. A stylus pen, comprising: main body; a tip configured to be exposed from the interior of the body to the exterior of the body; an inductor unit including a ferrite core disposed within the body and a coil wound in multiple layers around at least a portion of the ferrite core; as well as a capacitor unit arranged in the body to be electrically connected to the inductor unit so as to form a resonant circuit, Wherein, the dielectric constant of the ferrite core is less than or equal to 1000F / m, and The coil has a form in which adjacent winding layers are wound alternately, and the coil is an electric wire covered with two or more insulating wires.

2. The stylus pen according to claim 1, wherein: The coil is zigzag wound so that adjacent winding layers are inclined with respect to each other.

3. The stylus pen according to claim 1, wherein: The ferrite core includes nickel.

4. The stylus pen according to claim 1, wherein: The coil is formed as a litz wire.

5. The stylus pen as claimed in claim 1, further comprising: a bobbin configured to surround at least a portion of the ferrite core, and The coil is wound around at least a portion of the bobbin.

6. The stylus pen according to claim 1, wherein: The inductor unit includes two or more inductors connected in series.

7. The stylus pen according to claim 1, further comprising: A conductive preventing member is disposed on at least a portion of the inductor unit.

8. The stylus pen according to claim 7, wherein: The preventing member includes a slit for preventing the generation of eddy current, Opposite ends of the preventing member are spaced apart by the slit in the first direction, and The first direction is a direction in which the eddy current is generated.

9. The stylus pen according to claim 1, wherein: The inductor unit includes a plurality of inductors, and the capacitor unit includes a plurality of capacitors. The first resonant circuit includes a first inductor among the plurality of inductors and a first capacitor among the plurality of capacitors, a second resonant circuit including a second inductor among the plurality of inductors and a second capacitor among the plurality of capacitors, and The first resonant circuit and the second resonant circuit are connected in series.

10. The stylus pen according to claim 1, further comprising: A ground portion is configured to be electrically connected to a user.

11. A stylus pen, comprising: main body; a tip configured to be exposed from the interior of the body to the exterior of the body; as well as a resonant circuit, the resonant circuit being arranged in the body, Wherein, the resonant circuit comprises: a ferrite core disposed within the body; an inductor unit configured to include a coil wound in multiple layers around at least a portion of the ferrite core; and a capacitor unit, the capacitor unit being arranged in the body, Wherein, the dielectric constant of the ferrite core is less than or equal to 1000 F / m, the coil is wound in a zigzag shape so that adjacent winding layers are inclined to each other, and the coil is an electric wire covering two or more insulating wires.

12. The stylus pen according to claim 11, wherein: The ferrite core includes nickel.

13. The stylus pen according to claim 11, wherein: The coil is formed as a litz wire.

14. The stylus pen according to claim 11, further comprising: a bobbin configured to surround at least a portion of the ferrite core, and The coil is wound around at least a portion of the bobbin.

15. The stylus pen according to claim 11, wherein: The resonance circuit is formed to include two or more inductors and a capacitor unit connected in series.

16. The stylus pen according to claim 15, further comprising: A conductive preventing member is configured to surround at least a portion of the resonant circuit.

17. The stylus pen according to claim 16, wherein: The preventing member includes a slit for preventing the generation of eddy current, Opposite ends of the preventing member are spaced apart by the slit in the first direction, and The first direction is a direction in which the eddy current is generated.

18. The stylus pen according to claim 11, wherein: The resonant circuit includes two or more LC resonant circuits connected in series.

19. The stylus pen according to claim 11, wherein: The resonant circuit is connected to the tip and resonates an electrical signal transmitted from the tip, and The coil is electrically connected to the tip.

20. The stylus pen according to claim 11, further comprising: a ground portion configured to be electrically connected to a user, and Wherein, the capacitor unit is electrically connected to the ground portion and the tip.

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