JP6642272B2 - Coil device for electronic pen - Google Patents

Description

  The present invention relates to a coil device for an electronic pen mounted inside an electronic pen for inputting desired information to a computer, for example.

  There is a case where a coil device in which a wire is wound around a core body such as a ferrite core is built in an electronic pen for inputting desired information to a computer, for example, as shown in Patent Document 1. is there. An electronic pen incorporating such a coil device is required to have a structure that facilitates automatic winding of a wire.

  In particular, recently, there is a case where the diameter of an electronic pen is required to be reduced. For example, a conventional coil device for an electronic pen disclosed in Patent Document 1 or the like has been developed, and the automatic winding operation of a wire has been facilitated. Wiring is simple and the diameter of the pen can be reduced. Further, since a space is provided between the core and the terminal, the coil characteristics such as the Q value are improved.

  However, the conventional electronic pen coil device has a problem that the workability of assembling a concrete structure for providing a space between the core and the terminal is poor.

JP 2014-174563 A

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a coil device that can reduce the diameter of an electronic pen, improve coil characteristics, and have good assembling workability. .

In order to achieve the above object, an electronic pen coil device according to the present invention includes:
A core body that is disposed inside the electronic pen and has a first core end and a second core end respectively located on opposite sides in the axial direction;
A coil device for an electronic pen having a wire wound around the outer periphery of the core body to form a coil portion,
A wire guide is provided near the first core end on the outer periphery of the core body,
The wire guide has a terminal holding portion for holding a terminal so as to protrude in the axial direction from the first core end of the core body,
The terminal has a lead connection part connected to a lead part of the wire at a position separated from the terminal holding part in a circumferential direction.

  In the electronic pen coil device according to the present invention, the terminal holding portion of the wire guide holds the terminal at a position distant from the first core end of the core body. Therefore, it is possible to secure a space between the first core end of the core and the terminal where no metal or magnetic material is present, and the coil characteristics such as the Q value are improved.

  Further, since the wire guide has a terminal holding portion for holding the terminal so as to protrude from the first core end of the core body in the axial direction, only the terminal is attached to the terminal holding portion. It is easy to pull apart. That is, attachment of terminals and the like becomes easy, and assembling workability is improved.

  Further, since the terminal has a lead connection portion connected to the lead portion of the wire at a position circumferentially separated from the terminal holding portion, the connection between the lead connection portion and the lead portion of the wire is facilitated. In addition, since the terminal holding portion and the lead connection portion are separated from each other in the circumferential direction, the terminal holding portion and the lead connection portion do not spread outward in the radial direction, which contributes to reducing the diameter of the electronic pen.

The terminal is
A mounting portion held by the terminal holding portion,
A base portion extending from the mounting portion toward the circuit board;
A wing portion extending in a circumferential direction between the attachment portion and the lead connection portion.

  According to such a configuration, aerial wiring is not required, wiring is facilitated, and the wiring does not protrude outward in the radial direction, thereby contributing to a reduction in the diameter of the electronic pen. Further, a space can be secured near the first core end of the core body, and a sensor or the like can be easily arranged in the space, which also contributes to a reduction in the diameter of the electronic pen. . Furthermore, since the wing has elasticity, it is possible to easily crimp the lead connecting portion formed at the tip of the wing, and it is easy to connect the wire to the lead. That is, it is possible to reduce the load acting on the connection portion of the terminal.

  The pair of lead connection portions may be arranged at substantially 180 degrees symmetrical positions with respect to the terminal holding portion. With such a configuration, when welding the lead portion of the wire to the lead connection portion, heat such as welding transmitted to one lead connection portion is less likely to be transmitted to the other lead connection portion, The accuracy and quality of welding are improved.

The wire guide is
A winding start position restricting portion for restricting a winding start position of the wire,
The winding start position restricting portion is disposed circumferentially away from the winding start position restricting portion, and at a distance corresponding to at least a wire diameter of the wire toward the first core end in the winding axis direction with respect to the winding start position restricting portion. A winding end position restricting portion for restricting a winding end position of the wire at a retracted position.

  In the electronic pen coil device according to the present invention, a method of forming a coil portion by winding a wire around the outer periphery of the core body is not particularly limited. For example, first, the first lead portion (one of both ends of the wire) of the wire is fixed to the first core end side of the core body. Next, after the wire is locked to the winding start position regulating portion of the wire guide, the wire is wound in a coil shape around the core body located between the wire guide and the second core end toward the second core end. Turn to form the first main coil portion.

  Then, at a predetermined position near the end of the second core, the wire is rewound in the wire guide direction to form a rewound portion on the main coil portion. Thereafter, the second lead portion of the wire (the other of the two end portions of the wire) is locked to the winding end position regulating portion, and then pulled out toward the first core end. The winding end position restricting portion is located at a position where the winding end position restricting portion is retracted toward the first core end in the winding axis direction at least a distance corresponding to a wire diameter of the wire.

  For this reason, before the second lead portion of the wire is locked to the winding end position regulating portion, the wire is wound around the core corresponding to the gap in the winding axis direction between the first layer main coil portion and the winding end position regulating portion. It will be wrapped directly around the body. In other words, the second lead portion of the wire is not locked to the winding end position regulating portion from the second layer above the first main coil portion, but is dropped to the first layer and directly wound around the outer periphery of the core body. Then, it is locked to the winding end position regulating portion.

  For this reason, it is possible to minimize the outer diameter of the coil portion, particularly at the winding end position of the wire where the outer diameter tends to increase. The predetermined position (rewind start position) near the second core end can be easily positioned by, for example, a chucking jig that holds the core body near the second core end.

  When winding a wire, the axial length of the wire to be wound is determined by a predetermined length divided by a rewind start position and a wire guide, and the wire is easily wound automatically, and the wire is easily wound. The positioning accuracy is improved, and a predetermined inductance (L), Q characteristic, frequency characteristic, and the like can be realized with high accuracy, and the position detection accuracy with the electronic pen also improves.

  The wire guide may be made of a different material from the core body, and may be attached to an outer periphery of the core body. When the wire guide is made of a material different from that of the core body, the processing of the wire guide becomes easy. At least one of the winding start position restricting portion and the winding end position restricting portion may be integrally formed by providing a convex portion or a concave portion on the outer periphery of the core body.

  The wire guide may be made of a synthetic resin. With this configuration, a space that does not include metal or magnetic material can be easily formed between the terminal attached to the terminal holding portion and the core body.

  The wire guide may be formed with guide grooves for guiding the lead portions of the wire. With this configuration, the lead portion is easily guided to the lead connection portion of the terminal by passing the lead portion through the guide groove.

  The terminal is preferably a metal terminal, and each lead of the wire may be caulked to a lead connection of the terminal.

FIG. 1 is a perspective view of an electronic pen coil device according to an embodiment of the present invention. FIG. 2A is a schematic longitudinal sectional perspective view of a main part of the coil device taken along the line IIA-IIA in FIG. FIG. 2B is a partial cross-sectional rear view of the coil device taken along line IIB-IIB in FIG. 1. FIG. 3 is a perspective view showing details of a core body and a wire guide shown in FIG. FIG. 4 is a perspective view showing details of a core body, a coil and terminals shown in FIG. FIG. 5A is a perspective view of the wire guide. FIG. 5B is a perspective view of the wire guide viewed from a different angle from FIG. 5A. FIG. 5C is a perspective view of the wire guide viewed from a different angle from FIG. 5A. FIG. 5D is a perspective view of a wire guide used in a coil device according to another embodiment of the present invention. FIG. 6 is a schematic vertical sectional view of a main part of the coil device taken along the line IIA-IIA in FIG. FIG. 7 is a perspective view showing details of the terminals shown in FIGS.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  An electronic pen coil device 2 according to an embodiment of the present invention shown in FIG. 1 is mounted inside an electronic pen, and information on a change in a use state of the electronic pen, such as pressure or displacement applied to the electronic pen, together with position information of the electronic pen. Is used as a part of a device that transmits information on the input display screen such as a tablet in a non-contact manner.

  First, in this embodiment, the principle of detecting the position information of the electronic pen and the use state of the electronic pen will be briefly described.

  When a tuning circuit (including the coil unit 20 shown in FIG. 1) provided in the electronic pen is transmitted from an input display screen of a tablet (not shown) or the like, a radio wave of a predetermined tuning frequency, for example, a frequency f0, is transmitted. As a result, an induced voltage is induced in the coil section 20 shown in FIG. When the transmission of the radio wave is stopped, a radio wave of a predetermined frequency is transmitted from the coil unit 20 by the current based on the induced voltage. The position of the electronic pen (including the coil device 2) on the tablet (not shown) can be detected by receiving the radio wave transmitted from the tuning circuit including the coil unit 20 by the tablet (not shown).

  The pen tip 6a of the electronic pen core 6 is operated so as to be pressed against the surface of the tablet. During this operation, the core 6 moves in the axial direction inside the coil unit 20 and presses a pressing member (not shown) against one surface of the pressure-sensitive element. The pressure-sensitive element is formed of, for example, a variable capacitance capacitor, and the capacitance changes according to the pressing force (pressing displacement) acting on the element.

  This element is connected in parallel to a tuning circuit composed of a coil unit 20 and a capacitor mounted on a circuit board (not shown), and the tuning frequency of the tuning circuit changes according to the pressure applied to the element. Let it. In this case, when a wireless signal having a frequency f0 is transmitted from a tablet (not shown), since the tuning frequency of the tuning circuit has changed, the induced voltage generated in the coil unit 20 has a phase shifted from that during non-operation. Become. For this reason, a radio wave having a phase shifted from the radio wave transmitted from the tablet (not shown) is transmitted from the tuning circuit.

  An operation of the electronic pen can be detected by transmitting a radio wave from a tablet (not shown) to excite the tuning circuit and detecting a phase difference in a radio wave emitted from the tuning circuit. In accordance with the phase shift detected from the electronic pen, it is possible to detect the thickness of a line to be realized by the electronic pen, the hue and density (brightness) of a designated position or a designated area, and the like.

  Note that a method for detecting the thickness of a line to be realized by the electronic pen, the hue or the density (brightness) of a specified position or a specified area, and the like are not limited to the above-described methods. For example, by attaching a metal member to the pen body 6 on the opposite side of the pen tip 6a in the X-axis direction and detecting the Q characteristic that changes due to the axial movement of the core body 6 with respect to the coil unit 20, an attempt is made to realize the electronic pen. The thickness of the line that is present may be read.

The coil device 2 according to the present embodiment for realizing such a function of the electronic pen has a core body 4 that can be mounted inside the electronic pen. The core body 4 has a shaft hole 4a penetrating along the longitudinal direction (X axis), and is constituted by a hollow cylindrical body.
The core body 4 is made of a magnetic material, for example, a soft magnetic material such as a ferrite material or a permalloy, or a magnetic material formed by metal compacting. However, the core body 4 does not necessarily need to be a magnetic body, and may be made of a non-magnetic body such as a ceramic.

  In the drawings, an X axis, a Y axis, and a Z axis are perpendicular to each other, and in this embodiment, the X axis is a longitudinal direction of the core body 4, and the Y axis is a first lead portion 22a to be described later. And the second lead portions 22b are separated from each other.

  As shown in FIG. 2A, the cylindrical core body 4 is elongated in the X-axis (winding axis) direction along the inside of the electronic pen (not shown), and the first ends respectively located on opposite sides in the X-axis direction. And a distal end 4c as a second end. A wire guide 10 described below is joined to the base end 4b by, for example, adhesion.

  As shown in FIG. 3, in the present embodiment, the wire guide 10 is made of a nonmagnetic material different from the core body 4, for example, a synthetic resin. The wire guide 10 has an outer peripheral cover 12 having an inner peripheral surface 11 that matches the outer peripheral surface shape of the core body 4.

  As shown in FIGS. 5A to 5C, a plurality of positioning protrusions 11 a are formed on the inner peripheral surface 11 so as to extend in the circumferential direction along the X-axis direction. The plurality of protrusions 11a are in contact with the outer peripheral surface on the base end side of the core body 4 shown in FIG. 3, and the wire guide 10 can be attached to the outer periphery of the core body 4 substantially concentrically. An adhesive or the like may be applied to the gap between the protrusions 11a arranged at predetermined intervals in the circumferential direction, and the wire guide 10 can be fixed at a predetermined position with respect to the core body 4.

  Lead guide grooves 13a and 13b are formed at two locations in the circumferential direction of the outer peripheral cover 12, that is, on both sides of the outer peripheral cover 12 in the Y-axis direction, respectively, along the X-axis direction. A temporary fixing portion 14 having a narrow groove width is formed in the middle of the lead guide grooves 13a and 13b, but the temporary fixing portion 14 is not necessarily required. The groove width of the temporary fixing portion 14 is approximately equal to or less than the wire diameter of the lead portions 22a and 22b of the wire 22 constituting the coil portion 20, and the lead portions 22a and 22b are locked there and can be temporarily fixed. Has become. The groove width and groove depth of the lead guide grooves 13a and 13b are larger than the wire diameter of the lead portions 22a and 22b, and are about 1.1 to 1.5 times.

  At one location in the circumferential direction of the outer peripheral cover 12, that is, at the upper part in the Z-axis direction of the outer peripheral cover 12, as shown in FIGS. 1 and 3, project from the base end 4 b of the core body 4 in the X-axis direction. A terminal holding piece 18 as a terminal holding portion for holding the terminals 30a and 30b is formed integrally with the outer peripheral cover 12. In the present embodiment, the terminal holding piece 18 has an arcuate piece shape and is formed so as to protrude in the axial direction between the pair of lead guide grooves 13a and 13b. The circumferential width of the terminal holding piece 18 is preferably １ ／ to の, more preferably about ５〜 to の of the entire circumferential length of the cylindrical outer cover 12.

  The outer peripheral cover 12 covers the outer peripheral surface of the base end 4b of the core body 4, but the terminal holding piece 18 protrudes from the base end 4b of the core body 4 in the X-axis direction. On the outer peripheral surface of the terminal holding piece 18, terminal mounting grooves 17a and 17b are formed in parallel along the X-axis direction. A separating projection 15 is formed between the terminal mounting grooves 17a and 17b, and these terminal mounting grooves 17a and 17b are separated from each other.

  Blade guide grooves 16a and 16b are formed in the terminal mounting grooves 17a and 17b, respectively, and are continuously guided to the outside in the circumferential direction. The mounting grooves 17a and 17b and the guide grooves 16a and 16b are formed on the outer peripheral surface of the holding piece 18 projecting from the base end 4b of the core body 4 in the X-axis direction.

  An auxiliary projecting piece 19 is integrally formed at a lower portion of the outer peripheral cover 12 in the Z-axis direction so as to extend to the opposite side of the coil in the X-axis direction. The auxiliary protruding piece 19 is formed with a predetermined gap in the circumferential direction from the terminal holding piece 18, and the protruding length in the X-axis direction is shorter than the protruding length in the X-axis direction of the terminal holding piece 18. Has become.

  As shown in FIG. 3, it is preferable that the wire guide 10 is attached to the outer peripheral surface of the core body 4 so that the distal end of the auxiliary projecting piece 19 in the X-axis direction coincides with the base end 4 b of the core body 4. It is preferable that the terminal holding piece 18 protrude from the base end 4b of the core body 4 toward the opposite side of the coil along the X-axis direction. In addition, as shown in FIG. 5D, the auxiliary projecting piece 19 is not necessarily provided, and only the terminal holding piece 18 may be formed on the outer peripheral cover 12 so as to project in the X-axis direction.

  As shown in FIG. 1, the first mounting portion 32a of the first metal terminal 30a and the second mounting portion 32b of the second metal terminal 30b are fitted and mounted in each of the terminal mounting grooves 17a and 17b. Can be These may be attached to the inside of each of the terminal attachment grooves 17a, 17b with an adhesive. When mounting with an adhesive, each terminal mounting groove 17a, 17b is preferably formed longer in the X-axis direction than the mounting portions 32a, 32b. The mounting portions 32a, 32b are formed in the terminal mounting grooves 17a, 17b. It is preferable that a slight gap is formed in the X-axis direction in the state where each is attached. Note that these mounting portions 32a and 32b may be integrated inside the holding piece 18 at positions where the terminal mounting grooves 17a and 17b are formed. As means for integration, insert molding is exemplified.

  The first attachment portion 32a of the first terminal 30a and the second attachment portion 32b of the second terminal 30b are integrally formed with a first wing piece 31a and a second wing piece 31b, respectively. Through the guide grooves 16a, 16b, the terminal holding piece 18 extends toward both sides in the circumferential direction. At the tip of each of the first wing piece 31a and the second wing piece 31b, a first caulking piece 34a as a first lead connection part and a second caulking piece 34b as a second lead connection part are integrally formed. I have.

  The first caulking piece 34a and the second caulking piece 34b are arranged at substantially 180 degrees symmetrical positions with the terminal holding piece 18 interposed therebetween, but are not limited thereto. For example, by adjusting the circumferential lengths of the first wing piece 31a and the second wing piece 31b, the positions of the first caulking piece 34a and the second caulking piece 34b can be adjusted. For example, if the circumferential lengths of the first wing piece 31a and the second wing piece 31b are shortened, the positions of the first caulking piece 34a and the second caulking piece 34b are arranged near the terminal holding piece 18 and become longer. For example, they are arranged far away in the circumferential direction. In any case, the terminals 30a and 30b including the wing pieces 31a and 31b are separated from the base end 4b of the core body 4 by a predetermined distance X0 in the X-axis direction as shown in FIG. As shown in FIG.

  As shown in FIG. 4, the first lead portion 22a and the second lead portion 22b of the wire 22 are connected to the first caulking piece 34a of the first terminal 30a and the second caulking piece 34b of the second terminal 30b, respectively. As a connection method, the lead portions 22a, 22b may be attached to these caulking pieces 34a, 34b, caulked, and then resistance-welded. Alternatively, soldering or laser welding may be used. It is preferable that the connection of the first lead portion 22a and the second lead portion 22b to the caulking pieces 34a and 34b is performed after the coil portion 20 is formed.

  In the present embodiment, the first terminal 30a and the second terminal 30b are composed of two completely separated metal terminals, and are formed by bending and forming a metal piece punched and formed from a metal plate. You. The first terminal 30a has a first terminal base 36a extending in the X-axis direction. A first mounting portion 32a is formed on one end of the first terminal base 36a on the coil side in the X-axis direction, and a first board connection claw 38a is formed on one end of the first terminal base 36a on the opposite side of the coil in the X-axis direction. It is formed integrally by bending or the like. The first board connection claw 38a is connected to, for example, a circuit board (not shown). A capacitor and other circuit elements are mounted on the circuit board, and the first substrate connection claws 38a are electrically connected to circuits and elements mounted on the circuit board.

  The second terminal 30b is used as a pair with the first terminal 30a. As shown in FIG. 4, a second mounting portion 32b is formed at one end of the second terminal 30b on the coil side in the X-axis direction. The two-board connecting claw 38b is formed integrally by bending or the like. The second board connection claw 38b is connected to, for example, a circuit board (not shown). A capacitor and other circuit elements are mounted on the circuit board, and the second substrate connection claw 38b is electrically connected to a circuit or element mounted on the circuit board.

  As shown in FIG. 5A and FIG. 5B, a substantially semi-circular first end face 12 a constituting a winding start position regulating section and a winding end position regulating section are provided at the coil side end of the outer peripheral cover 12 in the X-axis direction. A substantially semicircular second end face 12b is formed. These end faces 12a and 12b are connected by a step 12c formed on the upper and lower sides in the Z-axis direction. That is, the first end face 12a and the second end face 12b are arranged so as to be displaced in the X-axis direction.

  As shown in FIG. 6, the first end face 12a and the second end face 12b are displaced in the X-axis direction, and the second end face 12b is shifted in the X-axis (winding axis) direction with respect to the first end face 12a. The wire 22 is retracted toward the base end 4b at least a predetermined distance x1 or more corresponding to the wire diameter of the wire 22.

  Next, the core body 4 and the coil section 20 will be described in detail. As described above, the wire guide 10 having the outer peripheral cover 12 that covers the outer periphery of the core body 4 is mounted near the base end 4 b on the outer periphery of the core body 4.

  In the present embodiment, the outer periphery of the core body 4 located between the first end surface 12a and the second end surface 12b of the outer peripheral cover 12 formed on the wire guide 10 and the rewind start position 21 winds the wire. This is a space for forming the coil unit 20. The unwinding start position 21 is a position where the chucking jig provided in the device for automatically winding the wire chucks the wire, and is an arbitrary position closer to the distal end 4c than the base end 4b of the core body 4. Can be set to

  The wire 22 forming the coil section 20 shown in FIG. 6 is not particularly limited, and for example, a litz wire, a USTC wire, a urethane wire, or the like is used. In particular, the use of a stranded wire such as a litz wire improves the Q characteristics at high frequencies and is particularly preferable as a coil device for an electronic pen.

  In the present embodiment, the method for forming the coil portion 20 by winding the wire 22 around the outer periphery of the core body 4 is not particularly limited. For example, first, the first lead portion 22a of the wire 22 is attached to the first caulking piece 34a. Temporarily fix with caulking. Alternatively, the first lead portion 22a of the wire 22 is temporarily fixed to the guide groove 13a of the wire guide 10 fixed to the base end 4b side of the core body 4. At that time, the first terminal 30a is not completely connected to the first lead portion 22a of the wire 22, but may be connected.

  Next, the wire 22 is engaged with the first end surface 12a, which is a winding start position regulating portion of the wire guide 10, through the guide groove 13a of the wire guide 10, and then is positioned between the wire guide 10 and the tip 4c. A first-layer main coil portion 20a (see FIG. 2) is formed around the outer periphery of the core body 4 by being densely wound in a coil shape in the direction of the core tip 4c. Then, at a predetermined position 21 near the core tip 4c, the wire is rewound in the direction of the wire guide 10 to form a rewound portion 20d (see FIG. 2) on the outer periphery of the main coil portion 20a. The unwinding section 20d has a first section 20b unwound at a first winding density and a second section 20c unwound at a second winding density less dense than the first winding density.

  After that, the second lead portion 22b of the wire 22 is pulled out in the direction of the core base end 4b through the guide groove 13b. At this time, as shown in FIG. 6, the second lead portion 22b of the wire 22 is locked to the second end surface 12b as the winding end position regulating portion, and then pulled out to the guide groove 13b. The second end face 12b is located at a position with respect to the first end face 12a toward the base end 4b along the X axis (winding axis) at least a predetermined distance x1 corresponding to the wire diameter of the wire 22.

  Therefore, before the second lead portion 22b of the wire 22 is locked to the second end surface 12b, the wire 22 corresponds to the gap in the winding axis direction between the first main coil portion 20a and the second end surface 12b. Is wound directly around the outer periphery of the core body 4. In other words, the second lead portion 22b of the wire 22 is not locked to the second end surface 12b from the second layer above the first main coil portion 20a, but is dropped to the first layer and applied to the outer periphery of the core body 4. After being wound directly, it is locked to the second end face 12b.

  Therefore, it is possible to minimize the outer diameter of the coil portion 20 particularly at the winding end position of the wire 22 where the outer diameter tends to be large. In this embodiment, the crimped attachment portions 32a, 32b are accommodated in the attachment recesses 16a, 16b of the wire guide 10, thereby effectively increasing the outer diameter of the attachment portions 32a, 32b. Can be prevented.

  Further, in the present embodiment, the wire guide 10 is made of a different material (for example, a synthetic resin) from the core body 4 and is attached to the outer periphery of the core body 4. It can be easily formed by displacing the second end face 12b in the X-axis direction.

  The winding direction of the wire 22 in the main coil portion 20a is the same as the winding direction of the wire 22 in the rewinding portion 20d. Therefore, the outer periphery of the core tip 4c of the core body 4 may be chucked with a chucking jig or the like, and the core body 4 may be rotated in the same direction around the axis. Then, the wire as shown in FIG. 6 can be formed simply by feeding out the wire from the nozzle, moving the nozzle along the X-axis direction, and changing the moving speed of the nozzle in the X-axis direction, and the coil section 20 can be easily formed. Formed.

  When the wire 22 is wound, the length of the wire 22 in the axial direction is determined by a predetermined length defined by the unwinding start position 21 and the wire guide 10, and the wire 22 is automatically wound. In addition to this, the positioning accuracy of the wire 22 is improved, the predetermined inductance (L), Q characteristics, frequency characteristics, and the like can be realized with high accuracy, and the position detection accuracy with the electronic pen is also improved.

  In addition, a rewind portion 20d is provided on the outer periphery of the main coil portion 20a, and both the first lead portion 22a and the second lead portion 22b are guided by the wire passages 13a and 12b of the wire guide 10, so that the aerial wiring is reduced. It becomes unnecessary. Further, it is easy to control the inductance (L) and the Q characteristic by adjusting the winding density and the like of the unwinding section 20d. Further, by reducing the axial length of the core body 4 or the winding width of the coil portion 20, space saving can be achieved. Further, by forming the rewinding portion 2d on the outer periphery of the main coil portion 20a, it is possible to prevent collapse of the winding.

  Moreover, in the present embodiment, as shown in FIG. 2A, the rewinding section 20d rewinds the first section 20b that has been unwound at the first winding density and the second section 20b that is less dense than the first winding density. And a certain second section 20c. Since the first section 20b of the rewinding section 20d is wound relatively densely, it functions as an auxiliary coil section for the main coil section 20a and contributes to an improvement in inductance. Further, since the second section 20c is relatively sparsely wound, the electrical resistance R and the parasitic capacitance C of the coil section 20 can be reduced, and the Q characteristic is excellent. In particular, in the first section 20b which is relatively densely wound, it is possible to effectively prevent the coil section 20 from collapsing. In addition, even in the second section 20c, a function to prevent the coil section 20 from collapsing can be expected to some extent as compared with the case where there is no rewind section.

  Note that the Q characteristic is (√ (L / C)) × 1 / R. The Q characteristic decreases as the electric resistance R and the parasitic capacitance C of the coil unit 20 increase, and the Q characteristic improves as the L increases. I do.

  The first winding density of the wire 22 in the first section 20b is preferably tightly wound with a winding density substantially equal to the winding density of the main coil portion 20a. "Substantially equivalent" means that the winding density of the main coil portion 20a may be slightly lower as long as the first section 20b functions as an auxiliary coil. For example, the first winding density may be 1/2 to 1 times the winding density of the main coil portion 20a. The second winding density of the second section 20c is not particularly limited as long as it is lower than the first winding density. For example, the second winding density is preferably 1/30 to 1 times, and more preferably 1/30 times the winding density of the main coil portion 20a. Preferably, the winding density is 1/10 to 1 times.

  The winding density is defined as the number of turns of the wire per unit axial length. The winding density of the main coil portion 20a is a winding density realized by so-called close contact winding (adjacent wires of the same layer are bonded and wound), and is determined by the outer diameter of the wire 22 and the like.

  Moreover, in the present embodiment, the first section 20b is located on the outer periphery of the main coil section 20a near the core tip 4c. With such a configuration, it is possible to prevent winding collapse of the coil portion 20 in particular, and to contribute to improvement and stabilization of the L characteristic. The rewind start position 21 near the core tip 4c can be easily positioned by, for example, a chucking jig that holds the core body 4 near the core tip 4c.

  In particular, in the present embodiment, the terminal holding piece 18 of the wire guide 10 holds the terminal at a position away from the base end 4b of the core body 4. For this reason, it is possible to secure a space between the base end 4b of the core 4 and the terminals 30a and 31a where no metal or magnetic material exists, and the coil characteristics such as the Q value are improved.

  Further, the wire guide 10 has the terminal holding pieces 18 for holding the terminals 30a and 30b so as to protrude from the base end 4b of the core body 4 in the axial direction. It is easy to separate the base end 4b from the terminals 30a and 30b. That is, attachment of the terminals 30a, 30b and the like is facilitated, and assembling workability is improved.

  Furthermore, since the terminals 30a and 30b have crimping pieces 34a and 34b as lead connection parts connected to the lead parts 22a and 22b of the wire 22 at positions separated from the terminal holding piece 18 in the circumferential direction, each crimping piece is provided. Connection between the lead portions 34a, 34b and the lead portions 22a, 22b of the wire 22 is facilitated. In addition, since the terminal holding piece 18 and the caulking pieces 34a, 34b are located at positions separated from each other in the circumferential direction, they do not spread outward in the radial direction, which contributes to reducing the diameter of the electronic pen.

  Furthermore, in the present embodiment, the terminals 30a, 30b extend in the circumferential direction between the mounting portions 32a, 32b, the base portions 36a, 36b extending from the mounting portions 32a, 32b toward the circuit board, and the mounting portions 32a, 32b. Wing pieces 31a and 31b extending to According to such a configuration, aerial wiring is not required, and wiring is facilitated. Further, as shown in FIG. 2B, the terminals 30a and 30b including the wing pieces 31a and 31b and the swaging pieces 34a and 34b are arranged outside the core body 4 at positions not protruding outward in the radial direction of the outer peripheral cover 10. Therefore, the diameter of the electronic pen is reduced.

  Further, since the terminal holding pieces 18 of the wire guide 10 are also arranged outside the core body 4 at positions not protruding outward in the radial direction of the outer peripheral cover 10, a space is provided near the base end 4 b of the core body 4. Can be secured. Therefore, a sensor or the like can be easily arranged in the space, which also contributes to a reduction in the diameter of the electronic pen. Note that a part of the wing pieces 31a and 31b and the caulking pieces 34a and 34b do not overlap with the core body 4 in the axial direction, and therefore may slightly enter the core body 4 when viewed from the X-axis direction.

  Further, since the wing pieces 31a and 31b have elasticity, the caulking pieces 34a and 34b as lead connection portions formed at the tips of the wing pieces 31a and 31b can be easily caulked, and the wires can be formed. 22 can be easily connected to the lead portions 22a and 22b. That is, it is possible to reduce the load acting on the connecting portions (caulking pieces 34a, 34b) of the terminals 30a, 30b.

  Further, in the present embodiment, the pair of caulking pieces 34a, 34b are arranged at substantially 180 degrees symmetrical positions with the terminal holding portion interposed therebetween, so that the lead portions 22a, 22b of the wire 22 are attached to the caulking pieces 34a, 34b. For example, when welding by welding, heat transmitted to one caulking piece 34a, 34b or the like becomes difficult to transmit to the other caulking piece 34b, 34a, and the accuracy and quality of welding are improved.

  Further, since the wire guide 10 of the present embodiment is made of a synthetic resin, a metal or a magnetic material is provided between the terminals 30a and 30b attached to the terminal holding pieces 18 and the core body 4 along the X axis. It is possible to easily form a space that does not include the space.

  Note that the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  For example, in the above-described embodiment, the core body 4 is formed with the shaft hole 4a penetrating along the longitudinal direction (X axis), and the core body 6 is passed through the shaft hole 4a. Need not necessarily form a shaft hole. For example, in an electronic pen of a type in which the pen pressure is detected by changing the inductance without changing the capacitance, the shaft hole is not necessarily formed in the core body 4.

  Further, the core body 4 may have a polygonal cylindrical shape other than a cylinder, an elliptical cylindrical shape, or another cylindrical shape, or may not have a shaft hole, and may have a prismatic shape other than a cylindrical shape, or another cylindrical shape. Further, the core body 4 may have a shape whose cross-sectional shape changes along the X-axis direction.

  In the present embodiment, the material of the core 6 is not particularly limited, but may be made of a non-magnetic material such as a synthetic resin. When the core 6 is made of a non-magnetic material, the Q characteristic can be improved.

  Further, in another embodiment of the present invention, both the first section 20b and the second section 20c shown in FIG. 2 may be wound at a uniform winding density along the axial direction. May be changed. Further, in still another embodiment of the present invention, a section other than the first section 20b and the second section 20c may be provided on the main coil section 20a.

  In still another embodiment, instead of forming a wire guide separately from the core body 4, at least one of the winding start position regulating section and the winding end position regulating section is provided on the outer periphery of the core body with a convex portion or By forming the concave portion, it can be formed integrally.

  In the above-described embodiment, the swaged pieces 34a and 34b are formed as lead connection parts of the terminals 30a and 30b. However, the lead connection part may be not only the swaged piece but also a claw part. The shape is not particularly limited as long as it can connect the lead portions 22a and 22b of the wire 22.

2 Electronic pen coil device 4 Core body 4a Shaft hole 4b Base end (first core end)
4c ... Tip (end of second core)
6 Core 6a Pen tip 10 Wire guide 11 Inner peripheral surface 12 Outer peripheral cover 12a First end surface (winding start position regulating portion)
12b: 2nd end face (winding end position regulation part)
12c Step 13a, 13b Lead guide groove 14 Temporary fixing part 15 Separation convex part 16a, 16b Blade guide groove 17a, 17b Terminal mounting groove 18 Terminal holding piece (terminal holding part)
19 ... auxiliary projecting piece 20 ... coil part 20a ... main coil part 20b ... first section 20c ... second section 20d ... rewind part 21 ... rewind start position 22 ... wire 22a ... first lead part 22b ... second lead part 30a first terminal 30b second terminal 31a first wing piece 31b second wing piece 32a first mounting portion 32b second mounting portion 34a first caulking piece (lead connection portion)
34b ... 2nd caulking piece (lead connection part)
36a ... first terminal base 36b ... second terminal base 38a ... first board connection claw 38b ... second board connection claw

Claims (7)

A core body that is disposed inside the electronic pen and has a first core end and a second core end respectively located on opposite sides in the axial direction;
A coil device for an electronic pen having a wire wound around the outer periphery of the core body to form a coil portion,
A wire guide is provided near the first core end on the outer periphery of the core body,
The wire guide has a terminal holding portion for holding a terminal so as to protrude in the axial direction from the first core end of the core body,
The coil device for an electronic pen, wherein the terminal has a lead connection portion connected to a lead portion of the wire at a position circumferentially separated from the terminal holding portion. The terminal is
A mounting portion held by the terminal holding portion,
A base portion extending from the mounting portion toward the circuit board;
The coil device for an electronic pen according to claim 1, further comprising a wing portion extending in a circumferential direction between the attachment portion and the lead connection portion.   The coil device for an electronic pen according to claim 1, wherein the pair of lead connection portions are arranged at substantially 180 ° symmetrical positions with respect to the terminal holding portion. The wire guide is
A winding start position restricting portion for restricting a winding start position of the wire,
The winding start position restricting portion is disposed circumferentially away from the winding start position restricting portion, and at a distance corresponding to at least a wire diameter of the wire toward the first core end in the winding axis direction with respect to the winding start position restricting portion. The coil device for an electronic pen according to any one of claims 1 to 3, further comprising a winding end position restricting portion that restricts a winding end position of the wire at a retracted position.   The coil device for an electronic pen according to any one of claims 1 to 4, wherein the wire guide is made of a material different from that of the core body, and is attached to an outer periphery of the core body.   The coil device for an electronic pen according to claim 5, wherein the wire guide is made of a synthetic resin.   The coil device for an electronic pen according to any one of claims 1 to 6, wherein the wire guide has a guide groove through which a lead portion of the wire is guided.

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