Stylus pen

Abstract

To provide a capacitive resonance stylus pen that is capable of creating an adequate output signal.SOLUTION: A stylus pen comprises: a body part; a conducting chip exposed to the outside in the body part; and a resonance circuit part which is connected to the conducting chip, and makes an electric signal transmitted from the conducting chip resonate. An inductor of the resonance circuit part comprises a ferrite core and a coil wound in multiple layers on at least a part of the ferrite core. The ferrite core comprises nickel. In the coil, an adjacent winding layer is wound by inclining in a zigzag form and can be formed by a Litz wire.SELECTED DRAWING: Figure 17

Description

[Technical field]

[0001] The present disclosure relates to a stylus pen. [Background technology]

[0002] 2. Description of the Related Art A variety of terminals, such as mobile phones, smart phones, tablet PCs, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), and navigation systems, are equipped with touch sensors.

[0003] In such terminals, the touch sensor may be located on a display panel that displays images, or may be located in a region of the terminal body, such that a user can interact with the terminal by touching the touch sensor, thereby providing the user with an intuitive user interface.

[0004] A user can use a stylus pen for precise touch input. Stylus pens are classified into active stylus pens and passive stylus pens depending on whether they have a battery and electronic components inside.

[0005] Active stylus pens have the advantage of being superior in basic performance compared to passive stylus pens and providing additional functions (pressure, hovering, buttons), but they have the disadvantage that the pen itself is expensive and requires a power source to charge the battery, so there are not many actual users other than a few high-end users.

[0006] Passive stylus pens have the advantages of being cheaper and not requiring batteries compared to active stylus pens, but they have the disadvantage of being less capable of precise touch recognition compared to active stylus pens. Recently, however, in order to realize passive stylus pens capable of precise touch recognition, the inductive resonance method EMR (Electro Magnetic Resonance) method and the capacitive resonance method have been proposed.

[0007] The EMR method has excellent quality for writing / drawing, which is the core function of a stylus pen, but has the disadvantage of being thick and expensive because a separate EMR sensor panel and EMR driving IC must be added to the capacitance touch panel.

[0008] The capacitive resonance method uses a general capacitance touch sensor and touch controller IC, which does not require additional costs and improves the performance of the IC to support pen touch.

[0009] In the capacitive resonance method, the amplitude of the resonance signal must be large in order for the touch sensor to more accurately identify the touch by the stylus pen, and therefore the frequency of the drive signal transmitted from the touch sensor to the stylus pen must be almost the same as the resonance frequency of the resonance circuit built into the stylus pen. However, in the conventional capacitive resonance method, even if the resonance frequency and the frequency of the drive signal match, the signal transmission is difficult because the attenuation of the signal transmission is very large due to the very small capacitance formed between the touch sensor that outputs the drive signal and the pen tip that receives the drive signal. As a result, despite the long-term attempts of many touch controller IC vendors, there is still a lack of sufficient output signals and no vendor has succeeded in mass production.

[0010] Therefore, in order to manufacture a capacitive resonant stylus pen capable of generating a maximum output signal, how to design the internal resonant circuit and the structure of the pen are very important factors. Summary of the Invention [Problem to be solved by the invention]

[0011] The present embodiment provides a capacitive resonant stylus pen that can produce a sufficient output signal. [Means for solving the problem]

[0012] In order to achieve the above or other objectives, a stylus pen according to one embodiment includes a body portion, a conductive tip exposed to the outside within the body portion, a ferrite core located within the body portion, an inductor portion including a coil connected to the conductive tip and wound in multiple layers on at least a portion of the ferrite core, and a capacitor portion located within the body portion and electrically connected to the inductor portion to form a resonant circuit.

[0013] Here, the ferrite core may have a dielectric constant of 1000 or less, the coil may be wound in adjacent winding layers alternately, and the coil may be a wire surrounding two or more insulated wires.

[0014] Additionally, the ferrite core may include nickel and the coil may be formed from Litz wire.

[0015] The device may further include a ground portion capable of being electrically connected to a user, and may further include a bobbin surrounding at least a portion of the ferrite core, the coil being wound on at least a portion of the bobbin.

[0016] The inductor portion may further include a conductive blocking member surrounding at least a portion of the inductor portion. The blocking member may include a slit for blocking generation of eddy current, and both ends of the blocking member may be spaced apart by the slit along a first direction in which eddy currents are generated.

[0017] According to another embodiment, a stylus pen may include a body portion, a conductive tip exposed to the outside within the body portion, a resonant circuit portion located within the body portion and connected to the conductive tip, which resonates an electrical signal transmitted from the conductive tip, and a ground portion capable of being electrically connected to a user.

[0018] Here, the resonant circuit unit may include an inductor unit including a coil electrically connected to a ferrite core and the conductive chip located in the body unit and wound in multiple layers on at least a portion of the ferrite core, and a capacitor unit located in the body unit and electrically connected to the ground unit and the conductive chip. In this case, the ferrite core may have a dielectric constant of 1000 or less, the coil may be wound such that adjacent winding layers are inclined in a zigzag pattern, and the coil may be a wire surrounding two or more insulated wires.

[0019] Additionally, the ferrite core may include nickel and the coil may be formed from Litz wire.

[0020] In this case, the resonant circuit unit may be formed of two or more inductor units and one capacitor unit connected in series, or the resonant circuit unit may include two or more LC resonant circuits connected in series.

[0021] The resonant circuit may further include a conductive blocking member surrounding at least a portion of the resonant circuit unit. The blocking member may include a slit for blocking generation of eddy currents, and the slit may separate both ends of the blocking member from each other along a first direction in which eddy currents are generated. Effect of the Invention

[0022] The effects of the stylus pen according to the present disclosure will be described below.

[0023] According to at least one embodiment of the present disclosure, by presenting an optimal structure of the resonant circuit of the capacitive resonant stylus, it is advantageous to be able to generate a sufficient output signal even with a thin diameter.

[0024] At least one of the embodiments of the present disclosure has an advantage of providing a stylus pen that is resistant to external factors.

[0025] Further scope of applicability of the present disclosure will become apparent from the following detailed description, however, the detailed description and specific embodiments, such as preferred embodiments of the present disclosure, should be understood as merely illustrative, since various changes and modifications within the scope of the present disclosure will be apparent to those skilled in the art. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a conceptual diagram showing a stylus pen and a touch sensor. [Diagram 2] 1 is a diagram specifically illustrating a stylus pen and a touch sensor. [Diagram 3] FIG. 2 is a diagram specifically illustrating an inductor portion of the stylus pen. [Figure 4] FIG. 13 is a diagram showing inductance and Q value according to a change in frequency. [Diagram 5] FIG. 1 is a diagram showing an enameled wire. [Figure 6] FIG. 1 shows a Litz wire. [Figure 7] FIG. 1 illustrates a multiple layer winding scheme. [Figure 8] 13 is a graph showing the results of a comparative experiment. [Figure 9] 13 is a graph showing the results of a comparative experiment. [Figure 10] 13 is a graph showing the results of a comparative experiment. [Figure 11] 13A and 13B are diagrams illustrating another example of the inductor section. [Figure 12] 11 is a graph showing the magnitude of a resonance signal depending on the structure of the inductor section. [Figure 13] 11 is a graph showing the magnitude of a resonance signal depending on the structure of the inductor section. [Figure 14] FIG. 13 is a diagram illustrating another example of the resonant circuit unit. [Figure 15]FIG. 13 is a diagram illustrating another example of the resonant circuit unit. [Figure 16] 1 is an equivalent circuit showing the effect of parasitic capacitance due to a user's hand. [Figure 17] FIG. 1 is a conceptual diagram showing a stylus pen having an LLC structure. [Figure 18] 1A to 1C are diagrams showing various examples of blocking members. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may, however, be embodied in various different forms and should not be construed as being limited to the embodiments set forth herein.

[0028] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0029] Also, throughout the specification, when a part is said to "comprise" a certain component, this means that it may further include other components, but not excluding other components, unless specifically stated to the contrary. Also, when a part is said to be "on" another part, this means that it is directly on the other part, or there may be other parts intervening between them. In contrast, when a part is said to be "directly on" another part, there are no other parts intervening between them.

[0030] 1 is a conceptual diagram showing a capacitive resonant stylus pen and a touch sensor. As shown in FIG 1, a stylus pen 10 and a touch sensor 20 are placed close to each other.

[0031] The stylus pen 10 may include a conductive tip 11 , a resonance circuit portion 12 , a ground portion 18 , and a body portion 19 .

[0032] The conductive tip 11 is connected to the resonant circuit unit 12. The conductive tip 11 may be entirely or partially made of a conductive material (e.g., metal, graphite, conductive rubber, conductive fabric, conductive silicon, etc.). Also, the conductive tip 11 may be present inside a non-conductive housing, and a part of the conductive tip 11 may be exposed to the outside of the housing, but is not limited thereto.

[0033] The resonant circuit unit 12 resonates with a driving signal input from the touch sensor 20. For example, the resonant circuit unit 12 may resonate with a driving signal received from the touch sensor 20 via the conductive chip 11 as an LC resonant circuit. Here, the driving signal may be a Tx signal transmitted to a 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 a resonant frequency of the stylus pen 10 so as to generate a resonant signal in the stylus pen 10 by capacitive coupling or electrical self-resonance.

[0034] The resonant circuit unit 12 outputs a resonant signal due to resonance to the conductive tip 11 during a section where a drive signal is input and also during a portion of the following section. The resonant circuit unit 12 is located within the body unit 19 and is connected to a ground unit 18. The ground unit 18 may be grounded by the user's body in contact with the outer surface of the body unit 19.

[0035] The body portion 19 accommodates the elements of the stylus pen 10. In FIG. 1, the body portion 19 is shown in a shape in which the frustum portion and the column portion are integrally combined, but the two portions may be separated. The body portion 19 may have a shape such as a cylinder, a polygonal cylinder, a column shape with at least a portion curved, an entasis shape, a frustum of pyramid shape, a circular truncated cone shape, and the like, and is not limited to these shapes. The body portion 19 is hollow inside, so that the conductive tip 11, the resonant circuit portion 12, and the ground portion 18 can be accommodated therein.

[0036] The touch sensor 20 may include a channel electrode 21 and a window 22 above the channel electrode. The channel electrode 21, the conductive tip 11, and the window 22 may form a capacitance Cx.

[0037] FIG. 2 is a conceptual diagram specifically showing a stylus pen and a touch sensor.

[0038] 2, the stylus pen 10 includes a conductive tip 11, a capacitor portion 13, an inductor portion 14, a ground portion 18, and a body portion 19. The capacitor portion 13 and the inductor portion 14 form the resonant circuit portion 12 of FIG.

[0039] The conductive tip 11 may be connected to the capacitor portion 13 and / or the inductor portion 14 via a conductive connecting member, which may be, but is not limited to, a wire, a pin, a rod, a bar, etc. Also, the conductive connecting member may include the coil of the inductor portion 14.

[0040] The capacitor unit 13 may include a plurality of capacitors connected in parallel, each of which may have a different capacitance and may be trimmed during the manufacturing process.

[0041] Inductor section 14 may be located adjacent to conductive tip 11. Inductor section 14 includes a ferrite core and a coil wound around the ferrite core.

[0042] The capacitor unit 13 and the inductor unit 14 are connected in parallel, and a resonance signal is generated in response to a drive signal by LC resonance between the capacitor unit 13 and the inductor unit 14. Figure 3 is a conceptual diagram specifically showing the inductor unit of the stylus pen.

[0043] Referring to FIG. 3, the inductor section 14 includes a ferrite core 15 and a coil 16 wound around the ferrite core 15 .

[0044] At this time, the inductance of the inductor unit 14 is determined by the following Equation 1.

[0045]

number

[0046] As can be seen from Equation 1, the inductance is proportional to the 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 length of the turns of the coil 16.

[0047] The design of the inductor section 14 in the resonant circuit section 12 housed in the capacitive resonant stylus pen is very important. In particular, in designing the inductor section, the inductance L and the Q value are very important parameters, as shown in Fig. 4. Here, the Q value is a quantity that indicates the coil characteristics as a resonant circuit element, and is given by Q=2πfL / R, where L and R are the inductance and resistance of the coil, respectively, and f is the frequency. The higher the Q value of a coil is used, the sharper the resonant characteristics can be obtained.

[0048] In designing a capacitive resonant stylus pen, L should have a self-resonance frequency large enough for the frequency to be used, and the Q value should have a maximum value at the frequency to be used. To achieve this, the material of the ferrite core, the type of coil wire, and the winding scheme must be optimized. Also, a method is required that can obtain a high output signal while maintaining a thin pen diameter.

[0049] In the following embodiment, a design method of a capacitive resonant stylus pen that is most optimized among various ferrite core materials, coil wire types, and winding schemes will be described.

[0050] (1) Ferrite core material

[0051] In this embodiment, the ferrite core is made of manganese (Mn) and nickel (Ni).

[0052] (2) Wire type

[0053] The types of coil wire used in this embodiment were enameled wire and Litz wire.

[0054] As shown in Fig. 5, enameled wire 100 is an electric wire made by covering the surface of copper wire 101 with insulating enamel 102 and heating it at high temperature, and is used for windings and wiring in electric devices, communication devices, electric meters, etc. In this embodiment, an enameled wire with a total thickness T of 0.2 mm, a wire diameter (Φ) of 0.18 mm, and a covering thickness t of 0.01 mm was used.

[0055] As shown in Fig. 6, Litz wire 200 is a special insulated wire made by twisting together several thin insulated wires (100, for example, enameled wire) with a diameter of about 0.1 mm into one wire, and then covering it with an insulating coating 201 made of nylon or the like. Litz wire 200 can reduce the skin effect by increasing its surface area, and is used for coils in high-frequency circuits.

[0056] In this embodiment, a Litz wire having a total thickness T of 0.2 mm, a wire diameter Φ of 0.06 mm, and a coating thickness t of 0.007 mm was used.

[0057] (3) Winding method

[0058] In the embodiment of the present invention, in order to obtain a sufficient inductance value (i.e., a sufficient number of windings) in the limited space of a stylus pen, a winding method having a multi-layered winding structure is used. Specifically, two types of multi-layered winding methods are used, as shown in (A) and (B) of FIG. 7.

[0059] The winding scheme in Figure 7(A) is the simplest winding scheme, which is a sequential layer winding scheme in which the winding of the layer immediately above is started after the winding of the lower layer is finished. In this case, the winding of the layer immediately above starts at the point where the winding of the previous layer ends, and is hereinafter referred to as a U-type winding scheme.

[0060] The winding scheme of FIG. 7(B) is an alternate layer winding scheme in which adjacent winding layers are alternately wound, and the windings of adjacent layers are wound in a zigzag pattern. Hereinafter, this will be referred to as a zigzag type winding scheme. Such a zigzag type winding scheme has the advantage of minimizing the voltage difference between the windings of adjacent layers and reducing the winding self-capacitance. At this time, the winding self-capacitance, which is a type of parasitic capacitance, is a parameter that indicates the electric field energy stored in the winding.

[0061] Comparative experiment 1 (Comparison of characteristic values ​​by material)

[0062] The coil wire type was enameled wire, and the coil was wound using the U-type winding method. The ferrite core material was changed to manganese, nickel, and magnesium, and the Q value was measured.

[0063] The measurement results showed that there was almost no difference in the Q value characteristics of each core material, and the measured Q values ​​were far too low to be realized in products.

[0064] Comparative experiment 2 (Comparison of characteristic values ​​by winding type)

[0065] The Q value was measured for inductor 1 and inductor 2, which were manufactured with a ferrite core made of manganese (Mn), wound using a U-type winding method, and with the coil wire types being enameled wire and Litz wire, respectively.

[0066] FIG. 8 is a diagram showing the Q values ​​of inductor 1 and inductor 2 measured by changing the frequency using a KEYSIGHT TECHNOLOGIES E4980A precision LCR meter.

[0067] In Figure 8, a is a waveform showing the change in Q value versus frequency for inductor 1 (manganese core / enamel wire / U-type winding method), and b is a waveform showing the change in Q value versus frequency for inductor 2 (manganese core / litz wire / U-type winding method).

[0068] For inductor 2 made from litz wire, the Q value reaches nearly its maximum value at a frequency of about 400 kHz (frequency f1), while for inductor 1 made from enamel wire, the Q value reaches nearly its maximum value at a frequency of about 150 kHz (frequency f2).

[0069] Comparing Figures 8a and 8b, we can see that the maximum Q value of inductor 2 is approximately 1.5 times higher than the maximum Q value of inductor 1. This shows that litz wire is superior to enamel wire as an inductor coil that forms the resonant circuit of a stylus pen.

[0070] However, the maximum Q value of inductor 2 measured in comparison experiment 2 was also below the target value required for commercialization (Q target ) was only about half the level.

[0071] Comparative experiment 3 (Comparison of characteristic values ​​by winding method)

[0072] The Q value was measured for inductors 3 to 5, which were manufactured by changing the ferrite core material to manganese (Mn), changing the wire type to enameled wire and Litz wire, and changing the winding method to U type and zigzag type.

[0073] FIG. 9 is a diagram showing the Q values ​​of inductors 3 to 5 measured by a KEYSIGHT TECHNOLOGIES E4980A precision LCR meter while changing the frequency.

[0074] In Figure 9, a is a waveform showing the change in Q value versus frequency for inductor 3 (manganese core / enamel wire / U-type winding method), b is a waveform showing the change in Q value versus frequency for inductor 4 (manganese core / enamel wire / zigzag-type winding method), and c is a waveform showing the change in Q value versus frequency for inductor 5 (manganese core / litz wire / zigzag-type winding method).

[0075] As can be seen from the waveform in Figure 9c, inductor 5 made with the litz wire / zigzag winding method, the Q value reaches nearly its maximum value at a frequency of about 300 kHz (frequency f3). Inductor 4 made with the enamel wire / zigzag winding method and inductor 3 made with the enamel wire / U-type winding method, the Q value reaches nearly its maximum value at a frequency of about 150 kHz (frequency f2).

[0076] 9a, b, and c, it can be seen that the maximum Q value of inductor 5 is approximately 1.5 times higher than the maximum Q value of inductor 4, and more than twice as high as the maximum Q value of inductor 3. This shows that the zigzag-type winding method is superior to the U-type winding method for the inductor that forms the resonant circuit of the stylus pen.

[0077] However, the target value (Q target ) was only about three-quarters of the level

[0078] Comparative experiment 4 (Comparison of characteristic values ​​by core material)

[0079] In this embodiment, manganese and nickel are used as the material of the ferrite core. It is known that nickel generally has a magnetic permeability of 200-300, while manganese has a magnetic permeability of 3000-5000.

[0080] Since manganese used in this embodiment has a magnetic permeability about 15 times higher than nickel, assuming that the cross-sectional area and length of the coil are the same, the number of turns of manganese can be reduced by about 4 times compared to the number of turns of nickel 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 effective than nickel.

[0081] Meanwhile, since the inductor unit 14 has a complicated structure including a coil wound around a core, a parasitic capacitance is additionally formed, which reduces the Q value and thus reduces the amplitude of the resonant signal.

[0082] Parasitic capacitance formed in the inductor section 14 may occur between the wound coils and between the core and the coil, but by adopting the zigzag type winding method as described above, the parasitic capacitance between the wound coils can be reduced.

[0083] Meanwhile, in this embodiment, in order to reduce the parasitic capacitance between the core and the coil, core materials having a lower dielectric constant than manganese were tested, and as a result of the testing, it was found that nickel core is the optimal material for the ferrite core.

[0084] The important physical property of manganese and nickel, which are mainly used as ferrite core elements, is permeability, which has a significant effect on the inductance value as shown in Equation 1. However, in manganese and nickel as ferrite elements, permittivity is a physical property that is of little interest, and in fact, in the case of nickel, there is no related information even on the data sheet provided by the manufacturer.

[0085] In this embodiment, in order to confirm the permittivity of manganese and nickel, the permittivity of manganese and nickel was measured using an E4980A precision LCR meter from KEYSIGHT TECHNOLOGIES, and the measurement results are shown in Table 1 below.

[0086] [Table 1]

[0087] Measurement 1 and Measurement 2 were both measured using the same KEYSIGHT TECHNOLOGIES E4980A precision LCR meter, and Measurement 1 shows the dielectric constant automatically calculated by the measurement software. Measurement 1 shows that the dielectric constant of manganese is 2400, but the dielectric constant of nickel was not measured. Measurement 2 shows that the dielectric constant was calculated by measuring the capacitance, area, and distance between the ferrite cores, and Measurement 2 showed that the dielectric constant of manganese was 8300 and the dielectric constant of nickel was 2.

[0088] There was a large difference in the dielectric constant between Measurement 1 and Measurement 2, and in particular, in the case of Measurement 2, it was confirmed that there was a considerable error due to capacitance, area, distance, etc. However, the results of Measurements 1 and 2 show that the dielectric constant of nickel is at least 1 / 1000 smaller than that of manganese.

[0089] In comparative experiment 4, the Q value was measured for inductors 6 and 7, which were manufactured by changing the winding method to U type and zigzag type, with the ferrite core material changed to nickel and the wire type changed to Litz wire.

[0090] FIG. 10 is a diagram showing the Q values ​​of inductors 6 and 7 measured by a KEYSIGHT TECHNOLOGIES E4980A precision LCR meter while changing the frequency.

[0091] In Figure 10, a is a waveform showing the change in Q value versus frequency for inductor 6 (nickel core / litz wire / U-type winding method), and b is a waveform showing the change in Q value versus frequency for inductor 7 (nickel core / litz wire / zigzag-type winding method).

[0092] As can be seen from the waveform in Figure 10b, inductor 7, which was made using the nickel core / Litz wire / zigzag winding method, shows a maximum Q value at a frequency of about 400 kHz (frequency f5). Inductor 6, which was made using the nickel core / Litz wire / U-type winding method, shows a maximum Q value at a frequency of about 200 kHz (frequency f6). Comparing Figures 11a 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.

[0093] On the other hand, the maximum Q value of inductor 7 (nickel core / litz wire / zigzag type winding method) measured in comparison experiment 4 was below the target value required for commercialization (Q target ) was found to have been almost reached.

[0094] In the comparative experiments 1 to 4 described above, inductors were manufactured by changing the combination of ferrite core material, coil wire type, and winding scheme, and the Q value was tested. The test results showed that the highest Q value was obtained when the inductor part of the capacitive resonant stylus pen was designed with a nickel core, Litz wire, and zigzag type winding scheme. The maximum Q value of the inductor manufactured with such a combination was the target value for commercialization (Q target ) was found to have been reached.

[0095] Meanwhile, in this embodiment, an experiment was performed using a nickel core as the ferrite core and a Litz wire as the type of wire of the core, but similar results can be obtained when a material having a dielectric constant of 1000 or less is used as the ferrite core other than the nickel core, and when a wire in the form of one coil surrounding two or more insulated wires (strands) is used other than the Litz wire.

[0096] In this embodiment, in order to further reduce the parasitic capacitance between the core and the coil, in addition to using nickel, which has 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 can be used, as described below.

[0097] 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 around at least a portion of the bobbin 141. The bobbin 141 is fixed in close contact with the ferrite core 15 by the force of the winding of the coil 16. The bobbin 141 may include a material that is the same as or different from that of the body unit 19, and may include, for example, plastic or a metal with an insulating surface. Specifically, the bobbin 141 may be made of polyphenylene sulfide (PPS), liquid crystal polyester (LCP), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), phenolic resin, etc.

[0098] In this manner, when the bobbin 141 surrounds the ferrite core 15 and the bobbin 141 is wound with the coil 16, the value of the parasitic capacitance Cp2 in FIG. 11 can be set even smaller than the value of the parasitic capacitance Cp1 in FIG. 3 by increasing the distance between the ferrite core 15 and the coil 16.

[0099] 12, when inductor section 14 includes only ferrite core 15 and coil 16, the maximum amplitude of the resonant signal was measured to be about 2V (+1V to -1V). With reference to Fig. 13, when inductor section 14 includes ferrite core 15, bobbin 141, and coil 16, the maximum amplitude of the resonant signal was measured to be about 4V (+2V to -2V). That is, it can be confirmed that the amplitude of the resonant signal is larger when at least a portion of ferrite core 15 is surrounded by bobbin 141 and coil 16 is wound around bobbin 141.

[0100] Meanwhile, when nickel is used as the ferrite core to design an optimal inductor section according to the present embodiment, as described above, nickel has a magnetic permeability about 1 / 15 times lower than manganese, so the number of nickel windings must be about four times larger than the number of manganese windings to obtain the same inductance value. Therefore, there is a disadvantage that the diameter must be larger than that of manganese to obtain the same inductance.

[0101] In this embodiment, a method of using a plurality of inductors is proposed in order to obtain a high output signal while reducing the diameter of the stylus pen.

[0102] FIG. 14 shows an equivalent circuit of a method of connecting two inductors with a thin diameter in series and connecting a capacitor in parallel between both ends of the two inductors. Hereinafter, such a resonant circuit is referred to as an "LLC resonant circuit." Although FIG. 14 shows two inductors connected in series, the present embodiment is not limited to this, and three or more inductors can be connected in series. According to an LLC resonant circuit, since the inductance L is twice as large as that of a resonant circuit having one inductor and capacitor (hereinafter referred to as an "LC resonant circuit"), the capacitance must be reduced by half when designed. That is, the LLC resonant circuit can be made thinner in diameter than an LC resonant circuit, but has the disadvantage of being more sensitive to the effect of capacitance.

[0103] Meanwhile, Fig. 15 is a diagram showing an equivalent circuit of a method in which two LC resonant circuits are connected in series (hereinafter referred to as "LCLC resonant circuit") and two resonant signals are combined and output. Fig. 15 shows two LC resonant circuits connected in series, but the present embodiment is not limited to this, and three or more LC resonant circuits can be connected in series.

[0104] According to the LCLC resonant circuit, the resonant frequencies of the two resonant circuits must be the same, and therefore, there is a disadvantage that the resonant frequencies of the two resonant circuits must be tuned to be the same during the manufacturing process.

[0105] As described above, despite the increase in the number of windings that occurs due to the use of nickel as a ferrite core, by using two or more inductors as in Figures 14 and 15, it is possible to produce a stylus pen with a thin diameter by suppressing the increase in the diameter of the inductor section.

[0106] Meanwhile, when using a resonant circuit of the LLC type as shown in FIG. 14, in order to minimize the influence of the capacitance reduced by half, a stylus pen having the following structure can be adopted.

[0107] In FIG. 2, the stylus pen 10 is held by a user's finger or the like, and at this time, a parasitic capacitance Cf is formed by the finger and an internal conductor (coil or capacitor) of the stylus pen 10 .

[0108] FIG. 16 is an equivalent circuit showing the effect of the parasitic capacitance Cf caused by the user's hand. Referring to FIG. 16, the resonant frequency of the stylus pen 10 changes due to the parasitic capacitance (Cf, 40). Then, the frequency of the drive signal 30 and the resonant frequency of the stylus pen 10 do not match, and there is a problem in that the magnitude of the signal output from the stylus pen 10 decreases. At this time, the effect of the parasitic capacitance (Cf, 40) is greater in the LLC circuit shown in FIG. 14 than in the LC resonant circuit or the LCLC resonant circuit. This is because, when designed to the same resonant frequency, the capacitance of the LLC resonant circuit is 1 / 2 smaller than the capacitance of the LC resonant circuit or the LCLC resonant circuit.

[0109] A stylus pen that prevents a change in resonance frequency due to a user's grip will be described below with reference to FIG.

[0110] FIG. 17 is a conceptual diagram showing a stylus pen having an LLC structure.

[0111] As shown in FIG. 17, the stylus pen 10 includes a conductive tip 11, a capacitor portion 13, two inductor portions 14, 14', a blocking member 17, a ground portion 18, and a body portion 19.

[0112] Each of the inductor sections 14 and 14' includes two ferrite cores 15 and 15' and coils 16 and 16' wound around the ferrite cores 15 and 15'. At this time, the two inductor sections 14 and 14' are connected in series.

[0113] The isolating member 17 is a conductive member surrounding the capacitor portion 13 and the inductor portions 14 and 14', and can prevent the formation of parasitic capacitance due to the user's hand.

[0114] At this time, the blocking member 17 may be designed such that both ends of the blocking member 17 are spaced apart along the direction ED of the eddy current in order to minimize the influence of the eddy current generated in the stylus pen.

[0115] In this regard, the blocking member 17 will be described in detail with reference to (a) to (d) of FIG.

[0116] 17, a clockwise current flows through coils 16 and 16' in response to a drive signal transmitted from conductive tip 11, and a magnetic field is generated by the current flowing through coils 16 and 16'. At this time, a counterclockwise eddy current is generated in the opposite direction to the coil current due to the change in the magnetic field generated by the coil current, and a counterclockwise eddy current flows through blocking member 17.

[0117] 18(a), the blocking member 17 includes one slit GP that blocks the generation of eddy currents. The slit GP extends along a direction PD that is perpendicular to the eddy currents (counterclockwise in FIG. 18). Both ends 17a, 17b of the blocking member 17 are separated by one slit GP. In an embodiment, the slit GP may have a width of 0.03 mm or more along the direction ED of the eddy currents.

[0118] Although the slit GP has been described as extending along the direction PD perpendicular to the eddy current, the slit GP may extend along a direction inclined at a predetermined angle (more than 0 degrees and less than 90 degrees) to the direction PD. Both ends 17a, 17b of the blocking member 17 are spaced apart along the eddy current direction ED. Therefore, the eddy current cannot flow along the blocking member 17, and the generation of the eddy current is blocked.

[0119] 18(b), the blocking member 17 includes a plurality of first blocking portions 171. The plurality of first blocking portions 171 extend along a direction PD perpendicular to the eddy current, and are spaced apart from one another along the direction ED of the eddy current. Similarly, since the blocking member 17 includes a plurality of first blocking portions 171 spaced apart from one another along the direction ED of the eddy current, the eddy current cannot flow along the blocking member 17, and the generation of the eddy current is blocked. Although the plurality of first blocking portions 171 have been described as extending along the direction PD perpendicular to the eddy current, the plurality of first blocking portions 171 may extend along a direction inclined at a predetermined angle (more than 0 degrees and less than 90 degrees) to the direction PD.

[0120] 18(c), the blocking member 17 includes a plurality of second blocking portions 172. The plurality of second blocking portions 172 are spaced apart in a direction PD perpendicular to the eddy current, and both ends of each of the plurality of second blocking portions 172 are spaced apart from each other in the direction ED of the eddy current. Similarly, since both ends of each of the plurality of second blocking portions 172 included in the blocking member 17 are spaced apart from each other in the direction ED of the eddy current, the eddy current cannot flow along the blocking member 17, and the generation of the eddy current is blocked.

[0121] 18(d), the blocking member 17 includes a plurality of third blocking portions 173. The plurality of third blocking portions 173 are spaced apart from one another along the direction PD perpendicular to the eddy current and the direction ED of the eddy current. Similarly, since the plurality of third blocking portions 173 included in the blocking member 17 are spaced apart from one another along the direction ED of the eddy current, the eddy current cannot flow along the blocking member 17, and the generation of the eddy current is blocked.

[0122] Although the present embodiment has been described above, the detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention. [Explanation of symbols]

[0123] 10. Stylus pen 11 Conductive Tip 12 Resonant circuit section 13 Capacitor section 14 Inductor section 15 Ferrite core 16 Coils 17 Blocking member 18 Grounding part 19 Body 20 Touch Sensor 30 Drive signal 40 Parasitic Capacitance 100 Enamelled wire 101 Copper wire 102 Enamel 141 Bobbin 200 Litz wire 201 Insulation coating

Claims

1. Body and a chip exposed to the outside within the body; an inductor portion including a ferrite core located within the body and a coil wound in multiple layers on at least a portion of the ferrite core; a capacitor portion located within the body and electrically connected to the inductor portion to form a resonant circuit; Including, A stylus pen, wherein the dielectric constant of the ferrite core is greater than 0 F / m and less than or equal to 1000 F / m.

2. The stylus pen according to claim 1 , wherein the coil is wound such that adjacent winding layers alternate.

3. The stylus pen of claim 1 , wherein the coil is wound with adjacent winding layers slanted in a zigzag pattern.

4. The stylus pen of claim 1 , wherein the ferrite core comprises nickel.

5. The stylus pen of claim 1 , wherein the coil is a wire formed by surrounding two or more insulated wires.

6. The stylus pen of claim 5 , wherein the coil is formed from Litz wire.

7. further comprising a bobbin surrounding at least a portion of the ferrite core; The stylus pen of claim 1 , wherein the coil is wound on at least a portion of the bobbin.

8. The stylus pen of claim 1 , wherein the inductor unit is formed by connecting two or more inductor units in series.

9. The inductor unit is a plurality of inductors, and the capacitor unit is a plurality of capacitors, a first resonant circuit including a first inductor section among the plurality of inductor sections and a first capacitor section among the plurality of capacitor sections; a second resonant circuit including a second inductor portion among the plurality of inductor portions and a second capacitor portion among the plurality of capacitor portions; The stylus pen of claim 8 , wherein the first resonant circuit and the second resonant circuit are connected in series with each other.

10. The stylus pen according to claim 1 , further comprising a blocking member surrounding at least a portion of the inductor portion.

11. Body and a chip exposed to the outside within the body; a resonant circuit located within the body, the resonant circuit including an inductor section including a ferrite core located within the body and a coil wound in multiple layers on at least a portion of the ferrite core, and a capacitor section located within the body; Including, A stylus pen, wherein the dielectric constant of the ferrite core is greater than 0 F / m and less than or equal to 1000 F / m.

12. The stylus pen of claim 11 , wherein the ferrite core comprises nickel.

13. The stylus pen of claim 11 , wherein the coil is a wire formed by surrounding two or more insulated wires.

14. The stylus pen of claim 13 , wherein the coil is formed from Litz wire.

15. further comprising a bobbin surrounding at least a portion of the ferrite core; The stylus pen of claim 11 , wherein the coil is wound on at least a portion of the bobbin.

16. The stylus pen of claim 11 , wherein the resonant circuit includes two or more inductor sections and one capacitor section connected in series.

17. The stylus pen according to claim 11 , wherein the resonant circuit is formed by connecting two or more LC resonant circuits in series.

18. The stylus pen of claim 11 , wherein the coil is wound with adjacent winding layers slanted in a zigzag pattern.

19. The stylus pen according to claim 11 , wherein the resonant circuit resonates with a signal transmitted from an external electrode.

20. The stylus pen of claim 11 , further comprising a blocking member surrounding at least a portion of the resonant circuit.

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