Electronic pen and core body for electronic pen

Abstract

To provide a highly-reliable and easy-to-manufacture electronic pen which is sufficiently durable in a tough environment even if made thin.SOLUTION: A core body 24 includes a shaft portion 241 and a pen tip portion 242. The shaft portion 241 has a rod-shaped body and grooves Gv1, Gv2 arranged along a circumference of a side surface on one end side of the rod-shaped body. The pen tip portion 242 includes a hole 242H into which the one end side of the shaft portion 251 is inserted and includes protrusions Pr1, Pr2 formed on an inner wall surface of the hole 242H and to be fitted to the grooves Gv1, Gv2 of the shaft portion 241. When the core body 24 is attached to a casing 23, the groove Gv1 of the shaft portion 241 of the core body 24 is located outside an opening 23a of the casing 23.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electronic pen used as a position indicator for a position detection device mounted on an electronic device such as a tablet PC (Personal Computer) or a smartphone, and to a core body for the electronic pen used in the electronic pen. [Background technology]

[0002] Position detection devices and position indicators are used as input devices for electronic devices such as tablet PCs (Personal Computers) and high-function telephone terminals known as smartphones. Position indicators are generally pen-shaped and are called electronic pens or styluses. In this specification, pen-shaped position indicators are referred to as electronic pens. The core of an electronic pen is an important component of the electronic pen, as it affects the writing feel (writing quality). Since the operating surface (input surface) of the electronic device with which the nib comes into contact is made of glass or resin, various innovations have been made for the core of an electronic pen, taking into consideration various factors such as friction between the nib of the core and the operating surface and wear of the nib.

[0003] For example, Patent Document 1 (described below) discloses an invention in which a core body is composed of a tip portion made of an elastic material, a base portion made of a material harder than the elastic material of the tip portion, and a core body main body portion thinner than the base portion. The core body disclosed in Patent Document 1 makes it possible to change the writing feel and reduce friction with the operating surface of an electronic device. The applicant of the present application has also conducted research into forming a core body for an electronic pen by mixing fibers made of polyparaphenylene terephthalamide into a resin to reduce wear due to friction with the operating surface, and has already filed an international patent application (International Patent Application PCT / JP2021 / 003508). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-26359 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, electronic devices equipped with position detection devices have become smaller and thinner, and as a result, electronic pen cores have also become thinner. However, if the cores become thinner, their strength decreases and they become more susceptible to breakage, making it impossible to achieve a thin, highly reliable electronic pen. It is also desirable for electronic pen cores to have a good writing feel, not scratch the operating surface of the electronic device, and reduce wear on the pen tip of the core. It is also desirable for them to be as easy to manufacture as possible. Thus, when making electronic pen cores thinner, it is necessary to overcome challenges such as improving strength, improving writing feel, protecting the operating surface (input surface) of the electronic device, reducing wear on the pen tip, and simplifying manufacturing.

[0006] However, in the case of the invention disclosed in the aforementioned Patent Document 1, the tip portion, base portion, and core body portion of the core for the electronic pen are integrally formed by two-color molding (thermal welding), so all parts are made of resin. Therefore, it is thought that the strength may be insufficient when the core for the electronic pen is made thinner. Furthermore, even when the core for the electronic pen is formed by mixing fibers made of polyparaphenylene terephthalamide into the resin to reduce wear due to friction with the operating surface, the entire core is made of resin, so there are also concerns about strength when the core is made thinner. In the first place, it is difficult to construct a thin core body portion (shaft portion) using a resin mixed with fibers.

[0007] In view of the above, an object of the present invention is to provide an electronic pen that can sufficiently withstand hard use even when made thin, is highly reliable, and can be easily manufactured. [Means for solving the problem]

[0008] In order to solve the above problems, a core body that is a rod-shaped body and includes a shaft portion having a groove provided along the periphery of a side surface on one end side, and a hole portion into which the one end side of the shaft portion is inserted, and a pen tip portion having a protrusion provided on an inner wall surface of the hole portion that fits into the groove of the shaft portion; a cylindrical body, one end of which is an opening, and a housing having an attachment portion for the core body therein; Equipped with The shaft portion of the core body is a rod-shaped body with high strength different from the pen tip portion, and the groove portion of the shaft portion of the core body is provided at two locations separated in the longitudinal direction of the shaft portion, and the distance between the two groove portions is: The one The groove portion on the end side is longer than the width in the longitudinal direction of the shaft portion, When the one end side of the shaft portion is inserted into the pen tip portion, the length of the portion of the shaft portion that is not covered by the pen tip portion becomes longer than the length of the portion of the shaft portion that is covered by the pen tip portion, When the core body is inserted from the rear end side through the opening of the housing and attached to the attachment part, at least one of the two grooves in the shaft part of the core body The one The groove on the end side is located outside the opening of the housing. The present invention provides an electronic pen characterized by the above features.

[0009] With this electronic pen, the shaft and nib are separate components, allowing for the shaft to be made of a strong rod-shaped material and the nib to be made of a material that is resilient and resistant to friction. When one end of the shaft is inserted into the hole in the nib, the groove in the shaft and the protrusion in the nib fit together, preventing easy removal. When the core is attached to the inside of the housing, the nib of the core protrudes sufficiently from the housing, and the protrusion in the nib fits into the groove in the shaft, preventing the nib from coming off the shaft even when strong writing pressure is applied. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of an electronic device configured using an input device including a position detection device and an electronic pen. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of an electronic pen according to an embodiment. [Figure 3] 2A to 2C are diagrams illustrating the configuration of a core body for an electronic pen according to an embodiment. [Figure 4] 10A and 10B are diagrams for explaining a state in which a core body for an electronic pen is attached to a housing of the electronic pen according to the embodiment. [Figure 5] 10A and 10B are diagrams illustrating another example of the configuration of the pen tip portion of the electronic pen core body of the electronic pen according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of an electronic pen and a core body for an electronic pen according to the present invention will be described with reference to the drawings.

[0012] [Specific examples of electronic devices] An example of an electronic device equipped with a position detection device and capable of inputting instructions using an electronic pen used with the position detection device will be described with reference to Fig. 1. The electronic pen and electronic pen core body of the embodiment described below are applications of an electronic pen and electronic pen core body according to one embodiment of the present invention. The electronic device of this embodiment is, for example, a tablet PC or a smartphone (high-function mobile phone terminal) equipped with a display device such as an LCD (Liquid Crystal Display), and is composed of an electronic device main body 1 equipped with a position detection device, and an electronic pen 2.

[0013] The electronic device main body 1 is configured by stacking (overlapping) an LCD, two position detection sensors with different detection methods, a motherboard, etc. between a housing 1A and a front panel 1F. In this embodiment, one of the two position detection sensors with different detection methods is an electromagnetic induction type position detection sensor, and the other is a capacitance type position detection sensor.

[0014] An opening 1FW is provided in the front panel 1F. The opening 1FW is the same size as the display area of ​​the LCD display screen and the operation area for accepting input by a user using an electronic pen 2 or the like. In this embodiment, the operation area 1FW corresponding to the LCD display area may also be referred to as the operation surface on which input operations are performed by contacting the electronic pen 2. The housing 1A of the electronic device main body 1 is also provided with a storage section 11 for storing the electronic pen 2, which will be described later, and the electronic pen 2 is stored in the storage section 11 when not in use.

[0015] The electronic pen 2 is used to input information through an electromagnetic induction-type position detection sensor. The user takes out the electronic pen 2 stored in the storage section 11 as needed and performs a position indication operation on the operation area 1FW. The electronic pen 2 is suitable for use when inputting detailed information, such as inputting diagrams or pictures. The electronic device main body 1 is also equipped with a capacitance-type position detection sensor, and the user can perform operations such as selecting icons and display buttons by touching the operation area 1FW with their fingers. Of course, the user can also draw or input handwritten characters through the capacitance-type position detection sensor by touching the operation area 1FW with their fingers.

[0016] Therefore, suppose that an operation is performed with the electronic pen 2 on the operation area 1FW of the electronic device main body 1. In this case, an electromagnetic induction-type position detection sensor provided inside the electronic device main body 1 detects the position and writing pressure of the operation with the electronic pen 2, and a display control circuit (microcomputer) of the electronic device main body 1 controls the display processing on the LCD display screen accordingly. Similarly, suppose that an operation is performed with a finger or the like of a user's hand on the operation area 1FW of the electronic device main body 1 in this electronic device. In this case, a capacitance-type position detection sensor provided inside the electronic device main body 1 detects the position pointed by the finger or the like, and a display control circuit of the electronic device main body 1 controls the display processing on the LCD display screen accordingly.

[0017] As described above, the electronic pen 2 functions as an electromagnetic induction type position detection sensor, and is equipped with a coil and a capacitor (capacitor element) that form a resonant circuit, as will be described in detail later. In the electronic device of this embodiment, whether the electronic pen 2 is stored in the storage section 11 of the electronic device main body 1 can be detected, for example, by a mechanical switch or by sending and receiving a signal through electromagnetic induction with the coil of the resonant circuit of the electronic pen 2. As a result, when the electronic pen 2 is stored in the storage section 11, the electromagnetic induction type position detection sensor is not operated, and the position pointed by the electronic pen 2 is not detected, thereby realizing power saving in the electronic device main body 1.

[0018] [Electronic pen configuration example] Next, we will explain a configuration example of the electronic pen 2 that indicates a position to the electromagnetic induction type position detection sensor mounted on the electronic device main body 1 shown in Figure 1. Figure 2 is a diagram for explaining a configuration example of the electronic pen 2 of this embodiment, where Figure 2(A) is a cross-sectional view of the electronic pen 2 and Figure 2(B) shows an equivalent circuit of the electronic pen 2.

[0019] 2, the electronic pen 2 is configured by mounting various components for realizing the electronic pen function inside a housing 23. The ferrite core 22 is, for example, a cylindrical ferrite material, with an axial through-hole of a predetermined diameter (for example, diameter = 1 mm) for inserting a rod-shaped core body 24 (described in detail later) formed in a position including the center line in the axial direction.

[0020] The core 24 is inserted into the through hole of the ferrite core 22 so as to penetrate the ferrite core 22. That is, the core 24 is longer than the axial length of the ferrite core 22. The portion of the core 24 inserted into the through hole of the ferrite core 22 has a diameter slightly shorter than the diameter of the through hole, allowing it to slide axially within the through hole. The end portion (pen tip portion) of the core 24 that serves as the pen tip has a diameter longer than the diameter of the through hole of the ferrite core 22, and the tip is machined into a hemispherical shape so that it can be moved smoothly on an operation surface (operation area) such as a touch panel.

[0021] 2(A), a portion of a predetermined length including the center of the ferrite core 22 in the axial direction is a coil-wound portion where the coil 21 is wound along the axial direction, and the portions on either side of this are non-coil-wound portions where no coil is wound. That is, when the ferrite core 22 is viewed in the axial direction, the portion from the end on the pen tip side to the end of the coil-wound portion on the pen tip side is a first non-coil-wound portion where no coil is wound. Furthermore, the portion from the other end of the coil-wound portion to the end of the ferrite core 22 opposite the pen tip side is a second non-coil-wound portion where no coil 21 is wound.

[0022] Extension wires (conductor wires) 21a, 21b from both ends of coil 21 wound around ferrite core 22 are extended inside housing 23 to printed circuit board 26, which will be described later, and connected to capacitor Cf provided on printed circuit board 26. This forms a resonant circuit by coil 21 and capacitor Cf on printed circuit board 26, and allows signals to be transmitted and received between coil 21 and an electromagnetic induction-type position detection device by electromagnetic induction.

[0023] A connecting portion 25, which is made up of a molded portion 25A, a writing pressure detecting portion 25B, a fitting portion 25C, and a connecting terminal portion 25D, is provided on the side of the core 24 opposite the pen tip. This connecting portion 25 integrally connects the pen tip side portion, which is made up of the coil 21, ferrite core 22, and core 24, with a printed circuit board 26 and a circuit board protection pipe 27, which will be described later. The molded portion 25A is a cylindrical portion made of resin or the like, and the outer periphery of the end face of the molded portion 25A facing the ferrite core 22 is slightly larger than the outer periphery of the coil-wound portion of the ferrite core 22. The end face of the molded portion 25A facing the ferrite core 22 is provided with a recess into which the second non-coil-wound portion of the ferrite core 22 fits.

[0024] 2(A), the molded portion 25A is provided therein with a core holding portion A1, a conductive rubber A2, a ring spacer A3, a dielectric A4, and a terminal member A5. These components are sandwiched between the molded portion 25A and a fitting portion 25C (described later) to form a writing pressure detection portion 25B that detects writing pressure.

[0025] Specifically, the core holder A1 is formed into a cup shape using, for example, hard rubber, and the end portion of the core 24 opposite the pen tip side is inserted into it to hold it. The bottom surface of the core holder A1 opposite the core 24 is formed into a spherical shape. The core holder A1 functions as a pressing part that presses the conductive rubber A2 in response to the writing pressure applied to the core 24. The conductive rubber A2 has a predetermined thickness and is the same shape and size as the opposing surface of the dielectric A4. The pen tip side surface of the conductive rubber A2 faces the spherical bottom surface of the core holder A1, and the other surface faces one surface of the dielectric A4 via the ring spacer A3.

[0026] The ring spacer A3 is a ring-shaped member that separates the conductive rubber A2 from the pen tip side of the dielectric A4 by providing a gap equal to the thickness of the ring spacer A3 between them. The dielectric A4 is made of a material whose dielectric properties are superior to its conductivity, such as ceramic, and acts as an insulator that does not conduct electricity when exposed to DC voltage. A terminal member A5 having a predetermined area is attached to the other surface of the dielectric A4. In this way, the conductive rubber (first electrode) A2 and the terminal member (second electrode) A5 sandwich the dielectric A4 to form a variable capacitance capacitor.

[0027] That is, the core 24 slides up and down in the axial direction in response to the writing pressure applied to the pen tip of the core 24. In response to this, the core holder A1 pushes the conductive rubber A2 up and down. Because a gap is created between the conductive rubber A2 and the dielectric A4 by the ring spacer A3, the conductive rubber A2 approaches and contacts the dielectric A4 in response to the writing pressure applied to the core 24, changing the contact area. As a result, the capacitance between the conductive rubber A2 and the terminal member A5, which sandwich the dielectric A4, changes in response to the writing pressure. Note that when no writing pressure is applied, the conductive rubber A2 moves away from the dielectric A4 due to the presence of the ring spacer A3.

[0028] The conductive wire connected to the conductive rubber A2 and the conductive wire connected to the terminal member A5 pass, for example, outside the molded portion 25A and the fitting portion 25C, and are connected to a terminal of a connection terminal portion 25D (described later), and are connected to the electronic circuit of the printed circuit board 26 through the terminal of the connection terminal portion 25D. This allows the electronic circuit portion of the printed circuit board 26 to detect the writing pressure applied to the core body 24 as a change in the capacitance of the variable capacitor configured as described above.

[0029] In this example, the writing pressure detection unit 25B, which is composed of the core holder A1, conductive rubber A2, ring spacer A3, dielectric A4, and terminal member A5, is similar to the writing pressure detection means of the well-known configuration described in, for example, Japanese Patent Application Laid-Open No. 5-275283. Writing pressure detection unit 25B can also be configured similar to the writing pressure detection means of the well-known configuration described in Japanese Patent Application Laid-Open No. 2011-186803. It can also be configured using a semiconductor element whose capacitance varies in response to writing pressure, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2013-161307.

[0030] The fitting portion 25C is a portion that fits with the board protection pipe 27, which will be described later. The fitting portion 25C is formed, for example, in a substantially cylindrical shape using resin, hard rubber, or the like, and is firmly fitted and integrated with the molded portion 25A. As a result, as described above, the core holding portion A1, the conductive rubber A2, the ring spacer A3, the dielectric A4, and the terminal member A5 are sandwiched between the molded portion 25A and the fitting portion 25C, and the writing pressure detection unit 25B composed of these members is stably held within the housing 23.

[0031] The inside of the fitting portion 25C is provided with a recess into which the tip of the printed circuit board 26, which will be described later, fits. The outer diameter of the fitting portion 25C is slightly longer than the inner diameter of the board protection pipe 27, allowing for a strong fit with the board protection pipe 27. When the board protection pipe 27 is fitted into the fitting portion 25C, the outer periphery of the board protection pipe 27 coincides with the outer periphery of the fitting portion 25C and the molded portion 25A.

[0032] 2(A), the connection terminal portion 25D is a portion consisting of two upper and lower plate portions connected to the fitting portion 25C. These plate portions are configured to sandwich the printed circuit board 26, which will be described later. In this case, the gap between the two upper and lower plate portions is slightly narrower than the thickness of the printed circuit board 26, so that the printed circuit board 26 can be sandwiched.

[0033] 2(A), the conductive rubber A2 and a terminal connected to the conductive wire from the terminal member A5 are provided so as to extend from the upper surface to the lower surface, wrapping around the end surface on the circuit board side. This allows automatic connection with the terminal of the electronic circuit provided on the printed circuit board 26 when the printed circuit board 26 is inserted into the connection terminal portion 25D.

[0034] The printed circuit board 26 is formed by mounting terminals to the electronic circuit and various circuit components that make up the electronic circuit on a rectangular insulating substrate, and providing wiring to connect them. The various circuit components include an IC (Integrated Circuit) that functions as a control circuit, multiple capacitors Cf, etc. The printed circuit board 26 is housed and protected inside a board protection pipe 27, as shown in FIG. 2(A).

[0035] The board protection pipe 27 is a rigid tubular member made of metal, carbon material, synthetic resin, or the like, and is resistant to breaking or bending. The board protection pipe 27 has a core-side opening and a rear-end opening at both ends. These core-side opening and rear-end opening are openings that intersect with the axial direction. The fitting portion 25C of the connection portion 25 is inserted into a predetermined area inside the board protection pipe 27 from the core-side opening, and the two fit together. Similarly, the pipe lid 28 is inserted into a predetermined area inside the board protection pipe 27 from the rear-end opening, and the two fit together. The pipe lid 28 also has a recess into which the end of the printed circuit board 26 is inserted.

[0036] As a result, core 24 is inserted from its rear end through opening 23a of housing 23, inserted into core holding part A1, and attached to housing 23 with its tip end portion protruding from housing 23. In other words, core holding part A1 constitutes an attachment part for core 24. In this case, the pen tip side portion where core 24 is inserted into ferrite core 22 around which coil 21 is wound, connection part 25, board protection pipe 27 that houses printed circuit board 26, and pipe cover 28 are integrally connected and housed in housing 23, thereby forming electronic pen 2.

[0037] The equivalent circuit of the electronic pen 2 of this embodiment is shown in Fig. 2(B). That is, a resonant circuit is formed by connecting in parallel the coil 21, the writing pressure detection unit 25B configured as a variable capacitor, and the capacitor Cf on the printed circuit board 26. This allows signals to be sent and received to and from a position detection device equipped with an electromagnetic induction type position detection sensor, which will be described later.

[0038] [Example of the structure of the core body for an electronic pen] 3A and 3B are diagrams illustrating the configuration of a core body for an electronic pen (hereinafter simply referred to as a core body) 24 according to an embodiment. As shown in the external view of Fig. 3A, the core body 24 is composed of a rod-shaped shaft portion 241 and a cup-shaped pen tip portion 242 whose tip is machined into a hemispherical shape and which has a hole on the rear end side.

[0039] In this embodiment, the shaft 241 is made of a carbon material. Carbon material is ten times stronger than iron and is less likely to break. Other characteristics of carbon material include excellent abrasion resistance, heat resistance, thermal expansion / contraction resistance, acid resistance, and electrical conductivity, making it suitable as a material for forming the shaft 241 of the thin core 24. The pen tip 242 is made of, for example, polyacetal resin (POM). Polyacetal resin has self-lubricating properties and a low coefficient of friction, resulting in excellent friction characteristics. Therefore, even when the pen tip 242 is placed in contact with the operation area (operation surface) 1FW of the electronic device main body 1 to perform an input operation, it is unlikely to damage the operation surface, and the pen tip 242 will not be excessively worn. Furthermore, polyacetal resin has high strength and excellent impact resistance, making it suitable as a material for forming the pen tip 242 of the thin core 24.

[0040] As shown in Fig. 3(A), one core 24 is formed by inserting shaft 241 into a hole in cup-shaped nib 242. As shown in the cross-sectional view of one end (nib side) of shaft 241 in Fig. 3(B), grooves Gv1 and Gv2 are provided along the periphery of the side surface of the end portion on the nib side of shaft 241. In other words, grooves Gv1 and Gv2 are ring-shaped recesses provided around the side surface of shaft 241 at different positions in the longitudinal direction of shaft 241.

[0041] 3(C), the nib portion 242 is provided with a hole 242H into which one end (nib side) of the shaft portion 241 is inserted. Ring-shaped protrusions Pr1 and Pr2 are provided along the inner wall surface of the hole 242H. The protrusions Pr1 and Pr2 are provided at positions corresponding to the grooves Gv1 and Gv2 of the shaft portion 241 when the shaft portion 241 is inserted into the hole 242H. Therefore, when the nib-side end of the shaft portion 241 is inserted into the hole 242H of the nib portion 242, the protrusion Pr1 of the nib portion 242 fits into the groove Gv1 of the shaft portion 241, and the protrusion Pr2 of the nib portion fits into the groove Gv2 of the shaft portion 241.

[0042] In this way, protrusions Pr1 and Pr2 provided on the inner wall surface of hole 242H of nib portion 242 fit into two grooves Gv1 and Gv2 spaced apart in the longitudinal direction of shaft portion 241, thereby enabling nib portion 242 to be firmly attached to shaft portion 241. Moreover, by simply inserting the side of shaft portion 241 on which grooves Gv1 and Gv2 are provided into hole 242H of nib portion 242 with a little force, nib portion 242 can be easily and firmly attached to shaft portion 241, and core body 24 can be configured.

[0043] [Core body mounting method] Fig. 4 is a diagram illustrating a state in which an electronic pen core is attached to the housing of the electronic pen according to the embodiment. As described with reference to Fig. 2, the core 24 is attached (mounted) inside the housing 23 by inserting its rear end into the opening 23a of the housing 23 and inserting it into the core holder A1. In this case, as shown in Fig. 4, the tip side of the pen tip portion 242 of the core 24 protrudes from the opening 23a of the housing 23, and at least the groove Gv1 of the shaft portion 241 is located outside the opening 23a of the housing 23.

[0044] 4, the front end surface Ff of the groove Gv1 of the shaft portion 241 of the core 24 is located to the left of the tip surface 23T of the housing 23, and the entire groove Gv1 is located outside the housing 23. This allows the tip side of the nib portion 242 of the core 24 to sufficiently protrude from the housing 23. Furthermore, because the groove Gv1 of the shaft portion 241 and the protrusion Pr1 of the nib portion 242 are fitted together on the outside of the housing 23, even if a relatively strong writing pressure is applied to the nib portion 242 of the core 24, the nib portion 242 will not come off the shaft portion 241, which is a problem.

[0045] As will be described later, one groove may be sufficient, but if there is one groove, the pen tip 242 may come off due to an impact or the like. If the pen tip 242 comes off and only the shaft 241 remains inserted in the pen, and if the groove Gv1 protrudes outward from the opening 23a, the shaft 241 of the core body can be removed from the pen by hooking it with the blade of a utility knife or the like. In other words, the groove Gv1 serves as a hook for removing the shaft 241 of the core body 24.

[0046] Furthermore, when the core body 24 of this embodiment is inserted rearward from the opening 23a of the housing 23 and attached to the core body holding part A1, a predetermined portion on the rearward side of the nib portion 242 is located inside the housing 23. In the example shown in Fig. 4, the portion slightly rearward of the protrusion Pr1 that fits into the groove Gv1 is located inside the housing 23. In the case of the core body 24 of this embodiment, as shown in Fig. 4, the groove Gv1 of the shaft portion 241 fits into the protrusion Pr1 of the nib portion 242 on the outside of the housing 23, and the groove Gv2 of the shaft portion 241 fits into the protrusion Pr2 of the nib portion 242 on the inside of the housing 23.

[0047] Therefore, the groove Gv2 of the shaft 241 and the protrusion Pr2 that fits therein are located within the housing 23. This allows the nib 242 to be more firmly attached to the shaft 241 and prevents the nib 242 from easily coming off or being damaged. For example, suppose the entire nib 242 attached to the shaft 241 protrudes from the housing 23. In this case, if something gets caught on the rear end surface of the nib 242 attached to the shaft 241, there is a possibility that the nib 242 will come off the shaft 241 or the rear end portion of the nib 242 will be damaged. However, in the case of the electronic pen 2 of this embodiment, as shown in FIG. 4, a predetermined portion on the rear end side of the nib 242 is located inside the housing 23, so there is no risk of the nib 242 coming off or the rear end side of the nib 242 being damaged.

[0048] Also, consider the case where the core 24 of the electronic pen 2 is inserted from the rear end side through the opening 23a of the housing 23 and attached to the core holding portion A1. In this case, the side surface 242Sd of a predetermined portion on the rear end side of the pen tip portion 242 and the inner wall surface 23In of the opening 23a of the housing 23 face each other parallel to each other with a small gap between them. As described above, when writing pressure is applied in the axial direction (the longitudinal direction of the electronic pen 2) to the core 24 attached within the housing 23, the core 24 slides and moves so as to be pushed into the housing 23, and the writing pressure can be appropriately detected via the writing pressure detection unit 25B. Furthermore, when the writing pressure is released, the core 24 that was pushed into the housing 23 is pushed out and returns to its original position.

[0049] In this case, side surface 242Sd of a predetermined portion on the rear end side of pen tip portion 242 and inner wall surface 23In of opening 23a portion of housing 23 face each other in parallel with a small gap. Therefore, the two do not come into contact with each other, and core body 24 can repeatedly slide in and out of housing 23 without stress in response to writing pressure, and writing pressure can be properly detected and provided to the electromagnetic induction type position detection device of electronic device main body 1.

[0050] [Another configuration example of the pen tip portion 242] 5 is a diagram illustrating another example of the configuration of the pen tip portion of the electronic pen core of the electronic pen according to the embodiment. In the above-described embodiment, the pen tip portion 242 of the core 24 is described as being formed from polyacetal resin, but this is not limited to this. For example, the pen tip portion 242 can be formed using various resins such as polyamide resin (PA), polyethylene terephthalate resin (PET), polycarbonate resin (PC), and ABS resin.

[0051] Furthermore, instead of simply forming the pen tip portion 242 from one type of resin, the pen tip portion 242 may be formed from a fiber-material-mixed resin in which a fibrous material is mixed into any of the base resins described above. The reason for mixing a fiber material into the base resin is that the electronic pen 2 is used by bringing the pen tip portion 242 into contact with the operation area (operation surface) 1FW of the electronic device main body 1, and therefore wear of the pen tip portion 242 can be reduced.

[0052] Fig. 5(A) is a diagram illustrating the pen tip 242A formed from a fibrous material-mixed resin formed by mixing a fibrous material into a base resin Bs. Note that the pen tip 242A shown in Fig. 5(A) also has a hole 242AH into which the shaft 241 is inserted, similar to the pen tip 242 shown in Fig. 3C. As shown in Fig. 5(A), protrusions PrA1 and PrA2 corresponding to the grooves Gv1 and Gv2 provided at one end of the shaft 241 are provided on the inner wall surface of the hole 242AH.

[0053] The pen tip 242A shown in FIG. 5A is formed by mixing polyacetal resin as the base resin Bs with polyparaphenylene terephthalamide (Kevlar®) fibers as the fibrous material Fi. As described above, polyacetal resin has excellent frictional properties. Furthermore, polyparaphenylene terephthalamide fibers are strong, heat-resistant, and flexible. Therefore, the pen tip 242A formed from a fibrous material-mixed resin in which polyparaphenylene terephthalamide fibers are mixed into polyacetal resin can further reduce wear during use and prevent damage to the operation area (operation surface) 1FW. Of course, since the frictional properties of polyacetal resin do not deteriorate, excessive loads on the operation area (operation surface) 1FW of the electronic device main body 1 can also be prevented, which could result in damage.

[0054] The fibers contained in the pen tip portion 242 are mixed into the resin so that they are arranged roughly along the curved surface of the pen tip portion. As a result, even if the resin wears away due to wear, the high-strength fibers will not damage the operation area (operation surface) 1FW.

[0055] Furthermore, the pen tip portion 242 may be formed not only from one type of resin but also from two types of resin. For example, the rear end side of the pen tip portion 242 may be formed from polyethylene terephthalate resin and the front end side from polyacetal resin. FIG. 5(B) is a diagram illustrating a pen tip portion 242B formed by so-called two-color molding, using different resins for the front end portion Tp and the rear end portion Rr. Note that the pen tip portion 242B shown in FIG. 5(B) also has a hole 242BH into which the shaft portion 241 is inserted, similar to the pen tip portion 242 shown in FIG. 3C. Projections PrB1 and PrB2 corresponding to the grooves Gv1 and Gv2 provided at one end of the shaft portion 241 are provided on the inner wall surface of the hole 242BH, as shown in FIG. 5(A).

[0056] The pen tip portion 242B shown in FIG. 5(B) is formed by using an elastomer for the tip portion Tp and polyacetal for the rear portion Rr. Elastomer is a general term for elastic polymers, such as rubber. Specific examples include natural rubber, synthetic rubber, urethane rubber, silicone rubber, and fluororubber. By using an elastomer for the tip portion Tp, a softer feel can be obtained when the pen tip comes into contact with the operation area (operation surface) 1FW of the electronic device main body 1, resulting in a better writing feel.

[0057] Unlike insert molding, two-color molding is a technology that creates a single molded product from two types of resin by alternately molding and heat-welding resins of different materials or colors in one cycle. Because different materials or resins of different colors can be firmly connected by heat welding, it is possible to create a single molded product that is highly reliable and does not separate, even though different materials or resins of different colors are used. Two-color molding is also sometimes called dissimilar material molding or double mode.

[0058] [Effects of the embodiment] In the electronic pen 2 of the above-described embodiment, the core 24 can be constructed by simply attaching the nib portion 242 to the shaft portion 241. In this case, the grooves Gv1 and Gv2 of the shaft portion 241 fit with the protrusions Pr1 and Pr2 on the inner wall surface of the hole 242H of the nib portion 242, allowing for a strong attachment so that the nib portion 242 does not easily come off the shaft portion 241. Furthermore, when the core 24 is inserted rearward through the opening 23a of the housing 23 and attached to the core holder A1, the groove Gv1 of the shaft portion 241 of the core 24 is positioned outside the opening 23a of the housing 23. This allows the tip side of the nib portion 242 of the core 24 to sufficiently protrude from the housing 23, resulting in a user-friendly electronic pen. These factors contribute to the realization of an electronic pen that can withstand hard use even when made thin, is highly reliable, and is easily manufactured.

[0059] These effects also apply to a core formed using nib portions 242A and 242B and shaft portion 241. Furthermore, when nib portion 242A is used, a slim core with reduced wear and a longer lifespan can be realized. Furthermore, when nib portion 242B is used, a slim core with a good writing feel can be realized.

[0060] [Variations] In the above-described embodiment, the shaft 241 of the core 24 is described as being made of a carbon material, but this is not limited thereto. It can be made of various materials that have a certain degree of strength when made into a rod-like body and that allow the grooves Gv1 and Gv2 to be formed at one end. For example, the shaft 241 can be made of a metal such as stainless steel. In this way, by forming at least the shaft 241 of the core 24 using a conductive material such as a carbon material or a metal, a capacitive electronic pen can also be made using a similar core.

[0061] In the above-described embodiment, two grooves Gv1 and Gv2 are provided at different positions in the longitudinal direction at one end of the shaft 241, but this is not limited to this. At least one groove may be provided at one end of the shaft 241. In this case, the protrusion Pr1 provided on the inner wall surface of the hole 242H of the nib 242 may also be provided as a single protrusion corresponding to the groove Gv1. However, in order to more firmly attach the nib 242 to the shaft 241 and maintain that state, it is preferable to provide two grooves Gv1 and Gv2 in the shaft 241 and two protrusions Pr1 and Pr2 on the inner wall surface of the hole 242H of the nib 242.

[0062] Furthermore, the grooves provided at one end of the shaft 241 and the protrusions provided on the inner wall surface of the hole 242H of the nib 242 can be provided in various ways. For example, a plurality of grooves may be formed at intervals around the side surface of one end of the shaft 241 so that they form a ring when connected. In this case, protrusions Pr1 and Pr2 may be formed at intervals along the inner wall surface of the hole 242H of the nib 242, corresponding to the grooves of the shaft 241, so that they form a ring when connected. Furthermore, it is possible to provide three or more grooves and protrusions in the axial direction, and the widths of the grooves and protrusions can be set to any appropriate width.

[0063] Furthermore, in the above-described embodiment, the shaft 241 is provided with the grooves Gv1 and Gv2, and the nib 242 is provided with the protrusions Pr1 and Pr2, but this is not limiting. A protrusion may be formed around the side surface of one end of the shaft 241, and a corresponding groove may be provided on the inner wall surface of the hole 242H of the nib 242. However, considering the overall strength of the nib 242, it is preferable to configure the shaft 241 with the grooves Gv1 and Gv2, and the nib 242 with the protrusions Pr1 and Pr2, as in the above-described embodiment.

[0064] In the above-described embodiment, the pen tip 242 is formed from polyacetal resin, or from polyacetal resin mixed with polyparaphenylene terephthalamide fiber, or from two-color molding of elastomer and polyacetal resin. However, this is not limited to these. Resins other than polyacetal resin can also be used as the resin material, such as polyamide resin, polyethylene terephthalate resin, polycarbonate resin, and ABS resin, as described above.

[0065] Furthermore, materials other than polyparaphenylene terephthalamide fiber may be used as the fibrous material. For example, carbon fiber, glass fiber, and various other fibers can be used. However, using high-strength, flexible polyparaphenylene terephthalamide fiber can satisfy both the need to suppress wear on the pen tip and the need to reduce the load on the operating surface. Furthermore, various elastomer materials, such as synthetic rubber and silicone rubber, can also be used. [Explanation of symbols]

[0066] 1...electronic device main body, 1F...front panel, 1FW...opening (operation area), 1A...housing, 11...storage section, 2...electronic pen, 21...coil, 21a, 21b...extended wire (conductor wire), 22...ferrite core, 23...housing, 23a...opening, 23T...tip surface of housing, 23In...inner wall surface, 24...core body, 241...shaft portion, Gv1, Gv2...groove portion, Ff...front end surface of groove portion, 242, 242A, 242B...pen tip portion, Bs...base resin, Fi...fibrous material, Pr1, Pr2 , PrA1, PrA2, PrB1, PrB2...protrusions, 242H, 242AH, 242BH...holes, 242Sd...side of pen tip, Tp...tip end portion, Rr...rear end portion, 25...connection portion, 25A...molded portion, 25B...pen pressure detection portion, A1...core body holding portion, A2...conductive rubber, A3...ring spacer, A4...dielectric, A5...terminal member, 25C...fitting portion, 25D...connection terminal portion, 26...printed circuit board, 27...circuit board protection pipe, 28...pipe cover, Cf...capacitor

Claims

1. a core body that is a rod-shaped body and includes a shaft portion having a groove provided along the periphery of a side surface on one end side, and a hole portion into which the one end side of the shaft portion is inserted, and a pen tip portion having a protrusion provided on an inner wall surface of the hole portion that fits into the groove of the shaft portion; a cylindrical body, one end of which is an opening, and a housing having an attachment portion for the core body therein; Equipped with The shaft portion of the core body is a rod-shaped body with high strength different from the nib portion, and the groove portions of the shaft portion of the core body are provided at two locations spaced apart in the longitudinal direction of the shaft portion, and the distance between the two groove portions is longer than the longitudinal width of the groove portion on the one end side of the shaft portion, based on the width of the groove portion on the one end side of the shaft portion, so that when the one end side of the shaft portion is inserted into the nib portion, the length of the portion of the shaft portion not covered by the nib portion is longer than the length of the portion of the shaft portion covered by the nib portion, When the core body is inserted from the rear end side through the opening of the housing and attached to the attachment part, at least one of the two grooves on the shaft part of the core body is located outside the opening of the housing. An electronic pen characterized by:

2. The electronic pen according to claim 1 , When the core body is inserted from the rear end side through the opening of the housing and attached to the attachment part, a predetermined part on the rear end side of the pen tip part is positioned inside the housing. An electronic pen characterized by:

3. The electronic pen according to claim 1 , The shaft portion of the core body is made of a carbon material. An electronic pen characterized by:

4. A cylindrical body having an opening at one end and a housing with an attachment portion for the core body therein, the core body being for an electronic pen, a rod-shaped body having a shaft portion with a groove provided along the periphery of a side surface on one end side; a pen tip portion including a hole into which the one end of the shaft portion is inserted, and a protrusion portion that fits into the groove of the shaft portion on an inner wall surface of the hole; It consists of The shaft portion of the core body is a rod-shaped body with high strength different from the nib portion, and the groove portions of the shaft portion are provided at two locations spaced apart in the longitudinal direction of the shaft portion, and the distance between the two groove portions is longer than the longitudinal width of the groove portion on the one end side of the shaft portion, based on the width of the groove portion on the one end side of the shaft portion, and when the one end side of the shaft portion is inserted into the nib portion, the length of the portion of the shaft portion not covered by the nib portion is longer than the length of the portion of the shaft portion covered by the nib portion, When the core body is inserted from the rear end side through the opening of the housing and attached to the attachment part, at least one of the two grooves on the shaft part of the core body is positioned outside the opening of the housing. A core body for an electronic pen.

5. The core body for an electronic pen according to claim 4, The shaft portion is made of a carbon material. A core body for an electronic pen.

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