Handwriting pen

Abstract

The invention relates to a handwriting pen. The disclosed stylus pen comprises: a ferrite core; and a coil including a plurality of metal wires twisted to have a number of turns per unit length of at least n, and wound on an outer surface of the ferrite core.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0153985 filed in the Korean Intellectual Property Office on November 8, 2023, and Korean Patent Application No. 10-2024-0083913 filed in the Korean Intellectual Property Office on June 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The invention relates to a stylus pen. Background Art

[0004] Various terminals, such as mobile phones, smart phones, tablet computers, notebook computers, digital broadcast terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), and navigation systems, are equipped with touch sensors.

[0005] In these terminals, the touch sensor may be located on a display panel that displays an image, or may be located on an area of ​​a terminal body. By allowing a user to interact with the terminal by touching the touch sensor, the terminal may provide the user with an intuitive user interface.

[0006] For complex touch input, users can use a stylus. These styluses can send and receive signals through the touch sensor through electrical and / or magnetic methods. Summary of the invention

[0007] The present invention seeks to provide a stylus for effectively receiving and transmitting magnetic signals received from and transmitted to an electronic device.

[0008] The present invention also seeks to provide a stylus pen that increases the Q value of an inductor.

[0009] An exemplary embodiment of the present invention provides a stylus pen including: a ferrite core; and a coil including a plurality of metal wires twisted to have at least n twist turns per unit length and wound on an outer surface of the ferrite core.

[0010] Another exemplary embodiment of the present invention provides a touch system, including: a stylus pen including an inductor unit and a capacitor, the inductor unit including a Litz wire cable including a plurality of metal wires twisted in a rotational form around a portion of a ferrite core, the capacitor being electrically connected to the inductor unit; and a touch screen including a touch electrode layer that receives a resonant electromagnetic signal from the stylus pen.

[0011] Yet another exemplary embodiment of the present invention provides a stylus pen including: an inductor unit including a coil wound around a portion of a ferrite core in a plurality of steps and including a plurality of metal wires twisted in a rotational form; and a capacitor unit electrically connected to the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a conceptual diagram showing a stylus pen and an electronic device.

[0013] Figure 2 is a diagram schematically illustrating a signal transmission operation between a stylus pen and an electronic device.

[0014] Figure 3 is a diagram schematically illustrating a signal transmission operation between a stylus pen and an electronic device.

[0015] Figure 4 is a diagram showing a stylus pen.

[0016] Figure 5 FIG. 1 is a conceptual diagram specifically showing an inductor unit of a stylus pen.

[0017] Figure 6 FIG. 1 is a conceptual diagram specifically showing an inductor unit of a stylus pen.

[0018] Figure 7 It is a diagram showing the number of twisted turns of the coil.

[0019] Figure 8 It is a diagram showing the number of twisted turns of the coil.

[0020] Fig. 9 It is a diagram showing the number of twisted turns of the coil.

[0021] Fig.10 It is a diagram showing the number of twisted turns of the coil.

[0022] Fig.11 is a cross-sectional view of a coil according to an exemplary embodiment.

[0023] Fig.12 is a cross-sectional view of a coil according to a comparative example.

[0024] Fig.13 is a graph showing a Q value depending on a frequency of an inductor unit according to an exemplary embodiment.

[0025] Fig.14 is a graph showing inductance, resistance, and Q value of an inductor unit including a coil according to a comparative example.

[0026] Fig.15is a graph showing inductance, resistance, and Q value of an inductor unit including a coil according to an exemplary embodiment.

[0027] Fig.16 is a graph showing the Q value of the inductor unit according to the number of twisted turns of the coil at a frequency of 600 kHz.

[0028] Fig.17 is a diagram showing a U-shaped winding scheme.

[0029] Fig.18 is a diagram showing a zigzag winding scheme.

[0030] Fig.19 This is a graph showing the Q value of an inductor unit measured by KEYSIGHT TECHNOLOGIES' E4980A precision LCR meter while changing the frequency.

[0031] Fig. 20 is a diagram showing an N-stage winding scheme.

[0032] Fig.21 is a conceptual diagram showing an inductor unit of a stylus pen using an N-stage type winding scheme.

[0033] Fig. 22 is a cross-sectional view of an inductor unit of a stylus using an N-stage winding scheme.

[0034] Fig.23 is a graph showing Q values ​​according to the number of twist turns and winding scheme. DETAILED DESCRIPTION

[0035] In the following detailed description, only certain exemplary embodiments of the present invention are shown and described by way of illustration. As those skilled in the art will appreciate, the described exemplary embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

[0036] Accordingly, the drawings and description are to be regarded as illustrative in nature, and not restrictive.Throughout the specification, like reference numerals refer to like elements.

[0037] In addition, for the sake of understanding and ease of description, the size and thickness of each structure shown in the drawings are arbitrarily shown, but the present invention is not limited thereto. In the drawings, for the sake of clarity, the thickness of layers and regions is exaggerated. In the drawings, for the sake of understanding and ease of description, the thickness of some layers and regions is exaggerated.

[0038] It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, no intervening elements are present. In addition, it should be understood that when an element (such as a layer, film, region, or substrate) is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present.

[0039] Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” should be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0040] Furthermore, throughout the specification, when referred to as a “plan view”, it means a case where the target portion is viewed from above, and when referred to as a “cross-sectional view”, it means a case where a cross section obtained by vertically cutting the target portion is viewed from the side.

[0041] In addition, unless an explicit expression such as "one" or "single" is used, an expression written in the singular form may be interpreted as the singular or the plural. Terms including common numbers, such as first and second, are used to describe various constituent elements, but the constituent elements are not limited by these terms. These terms may be used to distinguish one component from another.

[0042] The following examples will further illustrate the present invention. These examples are only intended to illustrate the present invention and are not intended to limit the scope of the rights protected by the present invention.

[0043] Figure 1 is a conceptual diagram showing a stylus pen and an electronic device.

[0044] refer to Figure 1 , the stylus pen 10 may receive a signal output from the electronic device 2 or the touch screen 20 near the touch screen 20 of the electronic device 2 , and may send a signal to the touch screen 20 .

[0045] Figure 2 is a diagram schematically illustrating a signal transmission operation between a stylus pen and an electronic device.

[0046] refer to Figure 2 The touch screen 20 a may include a window 21 , a touch electrode layer 22 , a display panel 23 , and a digitizer 24 .

[0047] Among passive styluses, in an electromagnetic resonance (EMR) stylus 10 , when the digitizer 24 transmits a magnetic signal B to the EMR stylus 10 , a resonant circuit included in the stylus 10 resonates with the magnetic signal B. The digitizer 24 may receive an input of the resonant magnetic signal B from the stylus 10 .

[0048] The digitizer 24 may be attached below the display panel 23 and may include a flexible printed circuit board (FPCB) having a plurality of conductive antenna loops and a ferrite sheet for shielding the magnetic field generated by the antenna loops and blocking eddy currents that may be generated by other electrical components when the antenna loops form a magnetic field.

[0049] The FPCB may be formed of multiple layers of multiple antenna loops for detecting the position of the input resonance signal. One antenna loop may overlap with at least one other antenna loop in the z-axis direction. Therefore, the thickness of the FPCB may increase, which may make the electronic device 2 (including the digital converter 24) Figure 1 The miniaturization of the device becomes difficult.

[0050] In some exemplary embodiments, when the digitizer 24 is mounted on the foldable / flexible electronic device 2, the FPCB attached to the folding area may be deformed. Repeated folding may cause stress to the wiring elements forming the antenna loop, which may eventually damage the wiring elements. In addition, the folding of the electronic device 2 may cause the ferrite sheet to deform.

[0051] Figure 3 is a diagram schematically illustrating a signal transmission operation between a stylus pen and an electronic device.

[0052] In the case where the stylus 10 includes a resonant circuit, when the electrodes of the touch electrode layer 32 transfer the magnetic signal B to the stylus 10 , the resonant circuit included in the stylus 10 may resonate based on the magnetic signal B. The electrodes of the touch electrode layer 132 may receive the resonant magnetic signal from the stylus 10 .

[0053] and Figure 2 Compared with the touch screen 20a in FIG. 1 , the touch screen 20b does not require additional units or modules (such as Figure 2 The digitizer 24 in the touch screen 20a is used to transmit the magnetic signal to the stylus 10, which can further reduce the thickness of the touch screen 20b. In addition, the touch screen 20b can be superior to the touch screen 20a in terms of manufacturing cost because the touch screen 20b does not use the expensive digitizer 24.

[0054] However, the internal resistance of the touch electrode layer 32 may be greater than the internal resistance of the digitizer 24. Typically, the internal resistance of the touch electrode layer 32 may be 10 times or more greater than the internal resistance of the digitizer 24, so that the driving current flowing to the touch electrode layer 32 may be one tenth or less of the driving current flowing to the digitizer 24.

[0055] When the driving current flowing to the touch electrode layer 32 is reduced, the magnetic signal received by the stylus pen 10 from the touch electrode layer 132 may be reduced, and thus the resonance signal generated by the stylus pen 10 may also be reduced.

[0056] The structure of the stylus pen 10 will be described below to supplement the lower magnetic signal transmitted to the stylus pen 10 due to the resistance of the touch electrode layer 32 .

[0057] Figure 4 is a diagram showing a stylus pen.

[0058] refer to Figure 4 , the stylus pen 10 includes a resonant circuit unit 12 in the housing. The resonant circuit unit 12 is an LC resonant circuit that can resonate with a driving signal output from the touch screen 20. The driving signal may include a signal (e.g., a sine wave or a square wave) having a frequency corresponding to the resonant frequency of the resonant circuit unit 12. For resonance, the resonant frequency of the resonant circuit unit 12 and the frequency of the driving signal need to be the same or very similar. The resonant frequency of the stylus pen 10 may be based on a design value of the resonant circuit unit 12 of the stylus pen 10. When Figure 3 When the touch electrode layer 32 in the stylus generates a magnetic field caused by a driving signal, the resonance circuit unit 12 of the stylus pen 10 may generate resonance using a signal received through a change in the magnetic field.

[0059] The components of the stylus pen 10 may be accommodated in the housing. The housing may have a shape such as a cylinder, a polygonal column, a column with at least a portion of the surface being curved, a convex shape, a truncated pyramid, a circular truncated cone, etc., but is not limited to the above shapes. The housing is hollow inside so that the housing may accommodate the components of the stylus pen 10, such as the resonant circuit unit 12, inside thereof. The housing may be made of a non-conductive material.

[0060] like Figure 4 As shown, the EMR stylus 10 may include a core 11 and a resonant circuit unit 12. The resonant circuit unit 12 may include an inductor unit 14 and a capacitor unit 13. The inductor unit 14 may include a ferrite core 15 penetrated by the core 11 and a coil 16 wound on the outer surface of the ferrite core 15.

[0061] The core 11 may have one end, ie, a pen tip, protruding from the ferrite core 15. The core 11 may be formed of an electrode core made of a conductor (eg, conductive metal) or a rigid resin mixed with conductive powder.

[0062] The ferrite core 15 may have a through hole with a predetermined diameter (eg, 1 mm) in the axial center direction for inserting the core 11 into the ferrite material, and the through hole may be, for example, cylindrical.

[0063] The coil 16 may be wound around the entire length in the axial center direction of the ferrite core 15, or it may be wound around a portion of the length. For example, the coil 16 may be wound around the ferrite core 15 at a spacing distance of 2 mm from the opposite side ends in the axial center direction of the ferrite core 15. In addition, the coil 16 may be electrically connected to the capacitor unit 13.

[0064] The capacitor unit 13 may include a plurality of capacitors connected in parallel. Each capacitor on the printed substrate may have a different capacitance and may be trimmed during the manufacturing process.

[0065] Figure 5 and Figure 6 is a conceptual diagram showing in detail an inductor unit of the stylus pen.

[0066] refer to Figure 5 , the inductor unit 14 may include a ferrite core 15 and a coil 16 wound on the ferrite core 15. The inductance of the inductor unit 14 is proportional to the magnetic coefficient μ, the cross-sectional area S of the coil 16, and the square of the number of windings N, L = μSN 2 / l, and is inversely proportional to the length l of the coil 16.

[0067] Although the ferrite core 15 is shown to have a cylindrical shape, the ferrite core 15 may have a polygonal shape, a column with at least a portion of the surface curved, a convex shape, a truncated pyramid, a circular truncated cone, etc., and is not limited to the above shapes.

[0068] refer to Figure 6 , the inductor unit 14 may include a ferrite core 15, a bobbin 17 wrapped around at least a portion of the ferrite core 15, and a coil 16 wound around at least a portion of the bobbin 17. The bobbin 17 may be fixed by a force caused by the winding of the coil 16 while being in close contact with the ferrite core 15. The bobbin 17 may include plastic or metal having an insulating surface. Specifically, the bobbin 17 may be made of polyphenylene sulfide (PPS), liquid crystal polyester (LCP), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and phenolic resin.

[0069] Due to the high dielectric constant of the ferrite core 15, parasitic capacitances Cp1 and Cp2 are generated between the ferrite core 15 and the coil 16, and when the bobbin 17 is wrapped around the ferrite core 15 and the coil 16 is wound around the bobbin 17, the distance between the ferrite core 15 and the coil 16 increases. Therefore, Figure 6 The value of parasitic capacitance Cp2 in Figure 5 The value of the parasitic capacitance Cp1 in.

[0070] Furthermore, the maximum amplitude of the resonance signal generated based on the inductor unit 14 including the parasitic capacitance Cp2 may be greater than the maximum amplitude of the resonance signal generated based on the inductor unit 14 including the parasitic capacitance Cp1 .

[0071] Figures 7 to 10 It is a diagram showing the number of twisted turns of the coil.

[0072] refer to Figures 5 to 10 , Figure 5 The coil 16 in may be a Litz wire cable 71, 81, 91, and 101 including six metal wires 1, 2, 3, 4, 5, and 6. The six metal wires 1, 2, 3, 4, 5, and 6 may be twisted in a manner rotated in the X direction.

[0073] The number of twisted turns per unit length of the coil 16 may be referred to as the number of twisted turns per unit length relative to Figure 5 The number of times that the plurality of metal wires 1, 2, 3, 4, 5 and 6 included in the coil 16 are wound around the ferrite core 15 from one point on the outer surface of the ferrite core 15 through another point and back to the point per unit length of the ferrite core 15.

[0074] For example, when one metal wire 1 among the six metal wires 1, 2, 3, 4, 5 and 6 is positioned to pass from one point on the boundary to another point and return to the point along the X direction of the ferrite core 15, the number of twisted turns of the coil 16 can be increased by +1N.

[0075] because Figure 7 The metal wire 1 is positioned to pass from one point on the boundary to another point and back to the point five times within 1 cm along the X direction of the Litz wire cable 71, so the number of twisted turns per unit length of the coil 16 can be 5 N / cm.

[0076] Similarly, due to Figure 8 The metal wire 1 is positioned to pass from one point on the boundary to another point and back to the point ten times within 1 cm along the X direction of the Litz wire cable 81, so the number of twisted turns per unit length of the coil 16 can be 10N / cm. Fig. 9The metal wire 1 is positioned to pass from one point on the boundary to another point and back to the point fifteen times within 1 cm along the X direction of the Litz wire cable 91, so the number of twisted turns per unit length of the coil 16 can be 15N / cm. Fig.10 The metal wire 1 is positioned to pass from one point on the boundary to another point and back to the point twenty times within 1 cm along the X direction of the Litz wire cable 101, so the number of twisted turns per unit length of the coil 16 can be 20 N / cm.

[0077] For ease of description, the Litz wire cables 71, 81, 91 and 101 having a twisted number of turns per unit length of the coil 16 of iN / cm (where i is a positive integer) are referred to as iN Litz wire cables. In this case, the twisted number of turns per unit length of the coil 16 and the unit length on which the twisted number of turns of the coil 16 is based are only for illustrative purposes.

[0078] Fig.11 is a cross-sectional view of a coil according to an exemplary embodiment.

[0079] refer to Figures 4 to 10 , the coil 16 may be a Litz wire cable including a plurality of metal wires 162 and an insulating sheath layer 161 wrapping the plurality of metal wires 162. The Litz wire cable has each metal wire 162 individually insulated by an insulating layer 163, thereby minimizing the skin effect, which is a phenomenon in which alternating current (AC) flows concentratedly near the surface of a conductor. In addition, the current flowing in the Litz wire cable may be evenly distributed on the plurality of metal wires 162, which may reduce interference from a magnetic field.

[0080] The diameter T of the coil 16 can be determined based on the number of metal wires 162, the wire diameter of the metal wires 162, and the diameter of the wires 162. The thickness t of the sheath layer of the metal wire 160 or the thickness of the insulating sheath layer 161 varies.

[0081] The size of the Litz wire cable may be specified as N / xx. N may refer to the number of metal wires 162 included in the Litz wire cable, and xx may refer to the wire diameter of the metal wire 162.

[0082] refer to Fig.11 , the coil 16 may include seven metal wires 162, and among the seven metal wires 162, a central metal wire 162b may be located at the center of the coil. Figures 7 to 10 , except for the central metal wire 162b, the metal wires 162 may be twisted in a form rotated in the X direction. However, the central metal wire 162b may not be twisted, but may extend in a straight line along the X direction. Therefore, the central metal wire 162b may not be included in the metal wires 162 on which the twisted turns of the coil 16 are based.

[0083] Fig.12 is a cross-sectional view of a coil according to a comparative example.

[0084] refer to Figures 4 to 12 The coil 16 may be a Litz wire cable including a plurality of metal wires 162 and an insulating sheath layer 161 wrapped around the plurality of metal wires 162. The Litz wire cable may be a Litz wire cable in which each metal wire 162 is individually insulated by an insulating layer 163.

[0085] The plurality of metal wires 162 may include seven center metal wires 162b located at the center of the coil. In addition to the center metal wires 162b, the metal wires 162 may be twisted in a form rotated along the X direction. However, the center metal wire 162b may not be twisted, but may extend in a straight line along the X direction. The metal wires 162 on which the twisted turns of the coil 16 are based only include the outermost metal wires 162, and therefore, the center metal wire 162b may not be included in the metal wires 162 on which the twisted turns of the coil 16 are based.

[0086] The number of metal wires 162 included in the coil and the number of metal wires 162 on which the number of twisted turns of the coil 16 is based are merely illustrative. However, the more the number of metal wires 162 included in the coil, the more the number of center metal wires 162b may be. However, even in this case, the number of twisted turns of the coil 16 may be determined based on the outermost metal wire 162 except the center metal wire 162b.

[0087] Fig.13 is a graph showing a Q value depending on a frequency of an inductor unit according to an exemplary embodiment.

[0088] Specifically, Fig.13 An inductor unit 14 ( Figure 4 ) and an inductor unit 14 ( Figure 4 Each of the three samples in (a) has a Q value in a frequency band from 0 kHz to 2000 kHz.

[0089] refer to Fig.13 , the Q value of the sample of the inductor unit 14 using the 5N Litz wire cable has a maximum value at a frequency of 500 kHz, and the Q value at 500 kHz may be 175. In the frequency range after 500 kHz, the Q value of the inductor unit 14 gradually decreases, so that the Q value of the inductor unit 14 at a frequency of 2000 kHz may be 140. In this case, the Q values ​​of the three samples of the inductor unit 14 including the 5N Litz wire cable may be similarly measured.

[0090] The Q value of the sample of the inductor unit 14 using the 15N Litz wire cable has a maximum value at 1000 kHz, and the Q value at 1000 kHz may be 230. In the frequency range after 1000 kHz, the Q value of the inductor unit 14 gradually decreases, so that the Q value of the inductor unit 14 at a frequency of 2000 kHz may be 170. In this case, the Q values ​​of the three samples of the inductor unit 14 including the 15N Litz wire cable may be similarly measured.

[0091] In the frequency band of 0 kHz to 2000 kHz, the Q value of the inductor unit 14 using the 15N Litz wire cable can be greater than the Q value of the inductor unit 14 using the 5N Litz wire cable. Figure 4 The amplitude of the magnetic signal resonating in the stylus pen 10 in FIG. 5 may be greater than the amplitude of the magnetic signal resonating in the stylus pen 10 including the inductor unit 14 using the 5N litz wire cable.

[0092] The larger the amplitude of the magnetic signal received by the touch electrode layer 32 from the stylus 10, the higher the signal-to-noise ratio (SNR) can be. Figure 3 The smaller the magnetic signal noise received by the touch screen 20b from the stylus pen 10, the touch electrode layer 132 can accurately detect the stylus pen 10 touching the touch screen 20b. Figure 3 In addition, due to the position of the touch screen 20b Figure 3 The larger the amplitude of the magnetic signal received by the touch screen 20b from the stylus pen 10, the smaller the amplitude of the minimum voltage at which the touch screen 20b detects the magnetic signal can be, thereby allowing the touch screen 20b to operate at low power. Therefore, compared with the stylus pen 10 including the inductor unit 14 using the 5N litz wire cable, the stylus pen 10 including the inductor unit 14 using the 15N litz wire cable can enable the touch screen 20b to accurately detect the touch position of the stylus pen 10 and allow the touch screen 20b to operate at low power.

[0093] Fig.14 is a graph showing inductance, resistance, and Q value of an inductor unit including a coil according to a comparative example, Fig.15 is a graph showing inductance, resistance, and Q value of an inductor unit including a coil according to an exemplary embodiment.

[0094] refer to Fig.14 , including 5N litz wire cable Figure 4 The average L value of three samples of the inductor unit 14 in may be 119.75 (H), the average R value may be 2.46 (Ω), and the average Q value may be 183.5.

[0095] refer to Fig.15, including 15N Litz wire cable Figure 4 The average L value of three samples of the inductor unit 14 in may be 120.36 (H), the average R value may be 2.26 (Ω), and the average Q value may be 200.9.

[0096] The Q value of the inductor unit 14 is proportional to the frequency F, the inductance L, and inversely proportional to the resistance R, that is, 2πFL / R. Since the average R value of the three samples of the inductor unit 14 including the 15N Litz wire cable is 2.26 (Ω), and the average R value of the three samples of the inductor unit 14 including the 5N Litz wire cable is 2.46 (Ω), the average Q value of the three samples of the inductor unit 14 including the 15N Litz wire cable can be higher than the average Q value of the three samples of the inductor unit 14 including the 5N Litz wire cable. This is because the coil ( Figure 5 The larger the number of twisted turns of the 15N Litz wire cable, the lower the resistance R value. Since the number of twisted turns of the 15N Litz wire cable is higher than that of the 5N Litz wire cable, the R value of the inductor unit 14 including the 15N Litz wire cable can be lower than the R value of the inductor unit 14 including the 5N Litz wire cable. Therefore, the Q values ​​of the three samples of the inductor unit 14 including the 15N Litz wire cable can be higher than the Q values ​​of the three samples of the inductor unit 14 including the 5N Litz wire cable.

[0097] Fig.16 is a graph showing the Q value of the inductor unit according to the number of twisted turns of the coil at a frequency of 600 kHz.

[0098] refer to Fig.16 , including 5N litz wire cable Figure 4 The Q value of the inductor unit 14 may have a large variation. As a result of measuring the Q value of the inductor unit 14 every 1 second within 5 seconds, the Q value of the inductor unit 14 may be measured as 190, 196, 189, 199, and 190, respectively. It can be seen that the Q value of the inductor unit 14 including the 5N Litz wire cable has a larger deviation than the Q value of the inductor unit 14 including the 10N Litz wire cable, the Q value of the inductor unit 14 including the 15N Litz wire cable, and the Q value of the inductor unit 14 including the 20N Litz wire cable. Since the 5N Litz wire cable has a relatively smaller number of twisted turns compared to the 10N, 15N, and 20N Litz wire cables, the Q value of the inductor unit 14 including the 5N Litz wire cable may have a larger deviation than the Q value of the inductor unit 14 including the 5N Litz wire cable. Fig.11 The metal wire 162 in the welding tube may be twisted, which may cause cold welding problems when welding.

[0099] As a result of measuring the Q value of the inductor unit 14 including the 20N Litz wire cable every 1 second within 5 seconds, the Q values ​​of the inductor unit 14 may be measured as 202, 201, 205, 204, and 201, respectively. The Q value of the inductor unit 14 including the 20N Litz wire cable is always measured as greater than or equal to 200 within 5 seconds, which may be higher than the Q value of the inductor unit 14 including the 5N Litz wire cable. However, since the 20N Litz wire cable has a relatively large number of twisted turns compared to the 5N, 10N, and 15N Litz wire cables, insulation layer breakdown may occur due to the recovery inertia of the metal wire 162 of the inductor unit 14 including the 20N Litz wire cable.

[0100] As a result of measuring the Q value of the inductor unit 14 including the 10N Litz wire cable every 1 second within 5 seconds, the Q values ​​of the inductor unit 14 can be respectively measured as 196, 198, 199, 200, and 199. As a result of measuring the Q value of the inductor unit 14 including the 15N Litz wire cable every 1 second within 5 seconds, the Q values ​​of the inductor unit 14 can be respectively measured as 205, 202, 203, 204, and 204.

[0101] The Q value of the inductor unit 14 including the 10N Litz wire cable and the Q value of the inductor unit 14 including the 15N Litz wire cable can be measured to be close to 200 within 5 seconds. The inductor unit 14 including the 10N Litz wire cable and the inductor unit 14 including the 15N Litz wire cable can have more twist turns than the inductor unit 14 including the 5N Litz wire cable, which can reduce the probability of the metal wire 162 being twisted. The inductor unit 14 including the 10N Litz wire cable and the inductor unit 14 including the 15N Litz wire cable can have fewer twist turns than the inductor unit 14 including the 20N Litz wire cable, which can reduce the occurrence rate of insulation layer breakdown due to the recovery inertia of the metal wire 162.

[0102] Therefore, the Litz wire cable included in the inductor unit 14 may be a 10N Litz wire cable or a 15N Litz wire cable. However, since the Q value of the inductor unit 14 including the 15N Litz wire cable measured within 5 seconds is always higher than the Q value of the inductor unit 14 including the 10N Litz wire cable, it may be more preferable to use the 15N Litz wire cable for the inductor unit 14.

[0103] Fig.17 is a diagram showing a U-shaped winding scheme.

[0104] refer to Fig.17The U-type winding scheme is a sequential layer winding scheme in which the winding of the lower layer ends (e.g., 1→2→3→4) and the winding of the immediately previous layer begins (e.g., 5→6→7→8). In the U-type winding scheme, the winding of the immediately previous layer may start at the point where the winding of the previous layer ends (e.g., point 4). Although the U-type winding scheme is the simplest winding scheme, the length l of the coil can be increased because the winding continues to the end of the lower layer winding. Due to the increase in the coil length l, the inductance can be increased by L=μSN 2 / l and decreases, and Figure 4 The Q value of the inductor unit 14 in can be reduced by 2πFL / R.

[0105] Fig.18 is a diagram showing a zigzag winding scheme.

[0106] Fig.18 The zigzag winding scheme shown is an alternating layer winding scheme in which adjacent winding layers are wound alternately, and the windings of adjacent layers are wound in a zigzag pattern. This zigzag winding scheme can minimize the voltage difference between the windings of adjacent layers, thereby reducing the winding self-capacitance. However, the windings in the zigzag winding scheme may cause Figure 4 The structure of the inductor unit 14 becomes unstable, resulting in a lower Q value of the inductor unit 14.

[0107] Fig.19 This is a graph showing the Q value of an inductor unit measured by KEYSIGHT TECHNOLOGIES' E4980A precision LCR meter while changing the frequency.

[0108] refer to Fig.19 , waveform a shows the use of U-type winding scheme Figure 4 Waveform a is a waveform showing that the Q value of the inductor unit 14 varies with frequency, and waveform b is a waveform showing that the Q value of the inductor unit 14 using the zigzag winding scheme varies with frequency. The Q value of the inductor unit 14 made by the U-type winding scheme may have a maximum value at a frequency f1 near 150kHz. The Q value of the inductor unit 14 made by the zigzag winding scheme may have a maximum value at a frequency f2 near 100kHz.

[0109] refer to Fig.19 From the waveforms a and b, it can be seen that the maximum value of the Q value of the inductor unit 14 made by the Z-shaped winding scheme is about twice as high as the maximum value of the Q value of the inductor unit 14 made by the U-shaped winding scheme. Figure 4 In the inductor unit 14 of the resonant circuit of the stylus pen 10 , the Z-shaped winding scheme is superior to the U-shaped winding scheme.

[0110] However, even the maximum value of the Q value of the inductor unit 14 with the zigzag winding scheme may not reach the target Q value. It can be seen that the target Q value is about twice as high as the maximum Q value of the inductor unit 14 made with the zigzag winding scheme.

[0111] In some exemplary embodiments, the target Q value may be 200, the maximum value of the Q value of the inductor unit 14 having the zigzag winding scheme may be 100, and the maximum value of the Q value of the inductor unit 14 having the U-shaped winding scheme may be 50. In this case, since the amplitude of the magnetic signal resonating in the inductor unit 14 having the zigzag winding scheme and the inductor unit 14 having the U-shaped winding scheme is smaller, Figure 3 The touch electrode layer 32 in the embodiment may have difficulty in receiving a magnetic signal from the inductor unit 14 and detecting the magnetic signal based on the received magnetic signal. Figure 3 The touch position of the stylus pen 10 is shown in FIG.

[0112] Fig. 20 is a diagram showing an N-stage winding scheme.

[0113] refer to Fig. 20 , the N-step type winding scheme may be a winding scheme using both the U-type winding scheme and the Z-type winding scheme. Specifically, the N-step type winding scheme utilizes a sequential layer winding scheme of the U-type winding scheme, wherein the winding of the upper layer region starts immediately after the winding of the lower layer region ends, and the winding of the immediately upper layer region starts at the point where the winding of the lower layer region ends. However, the point where the winding of the lower layer region ends may be different from the U-type winding scheme.

[0114] For example, the U-type winding scheme winds the upper region when the winding of the lower region is completely completed, but the N-stage winding scheme divides the lower region into N regions and winds the upper region when the winding of each of the N lower regions is completed. In this case, there may be a plurality of upper regions, in which case the regions may be wound sequentially from the upper region closer to the lower region.

[0115] In addition, the N-step type winding scheme can minimize the voltage difference between adjacent windings by using a zigzag type winding scheme in which adjacent winding layers are alternately wound. However, the alternate winding layers in which the coils are alternately wound may be different from the zigzag type winding scheme.

[0116] For example, in a Z-shaped winding scheme, all adjacent wires are wound alternately, but in an N-step winding scheme having N segmented winding stacks 201, 202, 203 and 204, the wire can be wound from area 10 of the third layer of the first winding stack 201 to area 1 of the first layer of the second winding stack 202, the wire can be wound from area 10 of the third layer of the second winding stack 202 to area 1 of the first layer of the third winding stack 203, and the wire can be wound from area 10 of the third layer of the third winding stack 203 to area 1 of the first layer of the fourth winding stack 204.

[0117] The order number N of the N-step winding scheme and the number of layers included in each of the winding stacks 201, 202, 203, 204 may vary based on the Q value of the inductor. However, considering the target Q value, the order number N of the N-step winding scheme may be at least three or more. Fig. 22 Describe the Q value of the N-order winding scheme in detail.

[0118] In addition, when the number of steps in the N-step type winding scheme is too large, the structure may become unstable, which may affect the degradation of the Q value. Therefore, the number of steps N of the N-step type winding scheme may be at most 10 or less.

[0119] Fig.21 This is a conceptual diagram of an inductor unit of a stylus using an N-stage winding scheme.

[0120] refer to Fig.21 , the inductor unit 210 may include a ferrite core 211, and may include four winding stacks 212-a, 212-b, 212-c, and 212-d wound around the ferrite core 211. In some exemplary embodiments, the four winding stacks 212-a, 212-b, 212-c, and 212-d may be wound around the ferrite core 211. Figure 6 The bobbin 17 in the embodiment wraps at least a portion of the ferrite core 211 .

[0121] The inductor unit 210 may include a first winding connection area 213-a connected between a first winding stack 212-a and a second winding stack 212-b, a second winding connection area 213-b connected between the second winding stack 212-b and a third winding stack 212-c, and a third winding connection area 213-d connected between the third winding stack 212-c and a fourth winding stack 212-d.

[0122] The first winding connection area 213-a is Fig. 20 The region 10 of the third layer of the first winding stack 201 is connected to Fig. 20 The second winding connection region 213-b is the region where the region 10 of the third layer of the second winding stack 202 is connected to the region 11 of the first layer of the second winding stack 202. Fig. 20The third winding connection region 213-c is the region where the region 10 of the third layer of the third winding stack 203 is connected to the first layer of the third winding stack 203. Fig. 20 Region 1 of the first layer of fourth winding stack 204 is connected to the region 1 of the first layer of fourth winding stack 204 .

[0123] Fig. 22 is a cross-sectional view of an inductor unit of a stylus using an N-stage winding scheme.

[0124] refer to Fig. 22 , Figure 4 The left area P01 of the ferrite core 220 of the inductor unit 14 can be connected to Figure 4 The core 11 in the embodiment is adjacent to the core 11, and the right area P06 of the ferrite core 220 can be connected to the Figure 4 The capacitors 13 in are adjacent. Figure 4 The coil 16 in the inductor unit can be wound on the ferrite core 220 at a separation distance of 2 mm from the left area P01 and the right area P06 of the ferrite core 220. Therefore, the current flowing in the coil 16 does not leak into the core 11 or the capacitor 13.

[0125] The ferrite core 220 may be divided into a plurality of regions at regular intervals with respect to the axial center direction of the ferrite core 220, and the coils may be wound around the plurality of regions, respectively. For example, the region P02 is Fig. 20 The first winding stack 201 in the embodiment is wound around the first winding stack region on the ferrite core 220, and the region P03 is Fig. 20 The second winding stack 202 in the second winding stack is wound around the ferrite core 220, and the area P04 is Fig. 20 The third winding stack 203 in the third winding stack is wound around the ferrite core 220, and the area P05 may be Fig. 20 The fourth winding stack 204 in FIG. 1 is wound around a fourth winding stack region on the ferromagnetic core 220 .

[0126] Fig.23 is a graph showing Q values ​​according to the number of twist turns and winding scheme.

[0127] refer to Fig.16 , Fig. 20 and Fig.23 , Sample 1 can be a 15N Litz cable and N-step winding solution. Figure 4 The inductor unit 14, sample 2 may be a 0N Litz wire cable and a zigzag winding scheme. Figure 4 The inductor unit 14.

[0128] The Q value of sample 1 using a 15N Litz wire cable and an N-step winding scheme may be 200. On the other hand, the Q value of sample 2 using a 0N Litz wire cable and a zigzag winding scheme may be 150. The Q value of sample 1 configured based on the 15N Litz wire cable twist turns and the N-step winding scheme may be greater than the Q value of sample 2 configured based on the 0N Litz wire cable twist turns and the zigzag winding scheme.

[0129] Since the inductor unit 14 of the sample 1 Figure 3 The stylus 10 in Sample 1 has a greater Q value than the stylus 10 including the inductor unit 14 of Sample 2 , and thus the amplitude of the magnetic signal resonating in the inductor unit 14 of Sample 1 may be greater than the amplitude of the magnetic signal resonating in the inductor unit 14 of Sample 2 .

[0130] because Figure 3 The touch electrode layer 32 in the embodiment receives a magnetic signal with a larger amplitude from the stylus pen 10, so the touch electrode layer can accurately detect the stylus pen 10 touching the object. Figure 3 In addition, due to the position of the touch screen 20b in Figure 3 The amplitude of the magnetic signal received by the touch screen 20 b from the stylus pen 10 is larger, so the amplitude of the minimum voltage for the touch screen 20 b to detect the magnetic signal can be smaller, thereby allowing the touch screen 20 b to operate at low power.

[0131] Therefore, compared with the inductor unit 14 including the sample 2 Figure 3 Compared with the stylus 10 in the example of FIG. 1 , the stylus 10 including the inductor unit 14 of the sample 1 can enable the touch screen 20 b to accurately detect the touch position of the stylus 10 and enable the touch screen 20 to operate at low power.

[0132] Although the exemplary embodiments of the present invention have been described in detail, the scope of the present invention is not limited by the exemplary embodiments. Various changes and modifications made by those skilled in the art using the basic concept of the present invention defined in the appended claims should be interpreted as belonging to the scope of the present invention.

Claims

1. A stylus pen, comprising: Ferrite core; as well as A coil includes a plurality of metal wires twisted to have a twisted number of turns per unit length of at least n and wound on an outer surface of the ferrite core.

2. The stylus pen according to claim 1, wherein: The number of twist turns per unit length is the number of times the plurality of metal wires are wound from one point on the outer surface of the ferrite core through another point and back to the one point.

3. The stylus pen according to claim 2, wherein: The plurality of metal wires include a central metal wire located at the inner center of the coil and a plurality of outer metal wires located at the inner periphery of the coil, and The number of twist turns per unit length is the number of times the plurality of outer metal wires are wound from the one point on the outer surface of the ferrite core through the other point and back to the one point.

4. The stylus pen according to claim 2, wherein: The plurality of metal wires include a plurality of central metal wires located at the inner center of the coil and a plurality of outer metal wires located at the inner periphery of the coil, and The number of twist turns per unit length is the number of times the plurality of outer metal wires are wound from the one point on the outer surface of the ferrite core through the other point and back to the one point.

5. The stylus pen according to claim 2, wherein: The coil is wound to have a spacing distance from each of opposite ends of the ferrite core in an axial center direction.

6. The stylus pen according to claim 5, wherein: The ferrite core is divided into a plurality of regions at regular intervals with respect to the axial center direction of the ferrite core, and the coils are respectively wound around the plurality of regions.

7. The stylus pen according to claim 6, wherein: Each of the plurality of regions includes a lower layer region and an upper layer region disposed on top of the lower layer region, and when winding of the lower layer region ends, winding of the upper layer region starts.

8. The stylus pen according to claim 7, wherein: The upper layer region includes a first upper layer region and a second upper layer region, The first upper region is disposed on top of the lower region, and The second upper region is disposed on top of the first upper region.

9. The stylus pen according to claim 7, wherein: The coil is wound on a bobbin that surrounds at least a portion of the ferrite core.

10. A touch system comprising: a stylus pen including an inductor unit and a capacitor, the inductor unit including a Litz wire cable including a plurality of metal wires twisted in a rotational form around a portion of a ferrite core, the capacitor being electrically connected to the inductor unit; as well as A touch screen includes a touch electrode layer receiving a resonant electromagnetic signal from the stylus pen.

11. The touch system according to claim 10, wherein: The plurality of metal wires are twisted in a rotational form around a portion of the ferrite core while having a spacing distance from each of opposite ends of the ferrite core in an axial center direction.

12. The touch system according to claim 11, wherein: The ferrite core is divided into a plurality of regions at regular intervals with respect to the axial center direction of the ferrite core, and The litz wire cables are wound around the plurality of areas, respectively.

13. The touch system according to claim 12, wherein: Each of the plurality of regions includes a lower layer region and an upper layer region disposed on top of the lower layer region, and when winding of the lower layer region ends, winding of the upper layer region starts.

14. The touch system according to claim 13, wherein: The litz wire cable is wound around a first connection region that connects a first region and a second region adjacent to the first region, the first region being any one of the plurality of regions.

15. The touch system according to claim 14, wherein: The first connection region includes a connection region where an upper region of the first region is connected to a lower region of the second region through the Litz wire cable.

16. The touch system according to claim 15, wherein: The Litz wire cable is wound on a bobbin that surrounds at least a portion of the ferrite core.

17. A stylus pen, comprising: an inductor unit including a coil wound in a plurality of steps around a portion of a ferrite core and including a plurality of metal wires twisted in a rotational form; as well as A capacitor unit is electrically connected to the coil.

18. The stylus pen according to claim 17, wherein: The coil wound on the portion of the ferrite core in the plurality of steps is wound in a plurality of winding stack regions in which the ferrite core is wound, and a plurality of winding connection regions connect each of the plurality of winding stack regions.

19. The stylus pen according to claim 18, wherein: The multiple winding stack areas are areas where the ferrite core is divided into multiple areas and is wound by the coil while the coil is spaced apart from each of the two opposite ends of the ferrite core in the axial center direction, and each of the multiple areas includes multiple layers around which the coil is wound.

20. The stylus pen according to claim 19, wherein: The multiple winding connection areas connect a first winding stack area and a second winding stack area adjacent to the first winding stack area, and connect a first layer and a second layer, the first winding stack area is any one winding stack area among the multiple winding stack areas, the first layer is the highest layer among the multiple layers included in the first winding stack area, and the second layer is the lowest layer among the multiple layers included in the second winding stack area.

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