CN117043724A

CN117043724A - Electronic pen and core for electronic pen

Info

Publication number: CN117043724A
Application number: CN202280019750.6A
Authority: CN
Inventors: 田中航平; 金田刚典; 原英之; 山口登; 恒川徹
Original assignee: Wacom Co Ltd
Current assignee: Wacom Co Ltd
Priority date: 2021-05-13
Filing date: 2022-04-11
Publication date: 2023-11-10

Abstract

A core for an electronic pen, which has excellent detection characteristics for indicating a position and tilting, maintains sufficient strength, has a simple structure, and is easy to manufacture, and an electronic pen using the core. The portable electronic device is provided with a housing (2), a core (4), and a signal generation circuit (8), wherein the core (4) is mounted inside the housing (2) such that the front end in the axial direction protrudes from the opening (H) of the housing (2), and the signal generation circuit (8) generates a signal transmitted from the core (4). The core body (4) is composed of a core rod (41) and a protection member (42) covering the pen tip portion (41 a) and the shaft portion (41 b) of the core rod (41), and an intermediate portion (43) having a dielectric constant different from that of the protection member (42) is provided around the side surface of the shaft portion (41 b) of the core rod (41) so as to separate the shaft portion (41 b) from the protection member (42).

Description

Electronic pen and core for electronic pen

Technical Field

The present invention relates to an electronic pen used as a position indicator for a position detection device mounted on an information processing device such as a tablet PC (Personal Computer: personal computer), and a core for an electronic pen used in the electronic pen.

Background

As one of input devices for various electronic devices such as a high-function telephone terminal called a smart phone or the like and a tablet PC (Personal Computer: personal computer), a position detecting device and a position indicator are used. The position indicators are typically formed as pens, known as electronic pens, touch pens, and the like. There are various ways in which the position detecting means and the position indicator may be located. In the case of the active capacitance method (AES (Active Electrostatic) method), a signal from an oscillation circuit mounted on an electronic pen is sent (radiated) from a pen tip to a position detection sensor of a position detection device, thereby indicating the position on the position detection sensor.

The position detection sensor used in the active capacitance type position detection device is configured by disposing a linear transparent electrode on a display screen of a display device such as an LCD (Liquid Crystal Display: liquid crystal display) in an X-axis direction (lateral direction) and a Y-axis direction (longitudinal direction) of the display screen. The position detection device detects the indication position of the electronic pen based on the position of the linear transparent electrode of the position detection sensor that receives the signal (electric field) emitted from the electronic pen.

In the case of an active capacitance type electronic pen, as described above, since a signal from a signal generating circuit mounted on the electronic pen is sent out from a pen tip, conventionally, a core of the active capacitance type electronic pen is a cylindrical rod-shaped body, and the entire body is made of a conductive material. In the case of this conventional electronic pen, there are the following problems: when the pen tip is tilted and moved, the received signal detected by the position detecting device fluctuates, and the linear characteristic of the detected indication position deteriorates. This is due to: the signal (electric field) from the signal generating circuit is radiated not only from the tip (tip portion) of the core of the electronic pen but also from the shaft portion of the core.

That is, with the movement of the electronic pen, a signal (electric field) emitted from the shaft portion of the core is received by the linear transparent electrode of the position detection sensor. In this case, the shaft portion of the core is strongly received when it is located on the transparent electrode, and is weakly received when it is deviated from the transparent electrode, and a fluctuation phenomenon occurs in the reception signal received by the transparent electrode. Thus, the linear characteristic as the detection characteristic of the pointed position when the electronic pen is tilted is deteriorated.

Therefore, in order to improve the linearity of the detection characteristic as the indication position, as disclosed in patent document 1 described later, in the core of the active capacitance type electronic pen, it is considered that: the tip of the core is formed into a sphere, and the shaft portion is made as thin as possible. As disclosed in patent document 2 described later, it is considered that: the core body is formed by forming a core rod made of a conductive material into a tapered shape from the pen point side toward the rear end side, and covering the periphery thereof with a protective member.

Prior art literature

Patent literature

Patent document 1: japanese patent No. 5761773

Patent document 2: international publication No. 2020/054163

Disclosure of Invention

Problems to be solved by the invention

In the case of the invention disclosed in patent document 1, since the shaft portion having conductivity is thin, the influence of the signal (electric field) emitted from the shaft portion does not occur even if the shaft portion is inclined, and the nib of the sphere is used as a main body to participate in the emission of the signal (electric field), so that the range of the received signal is not expanded, and a good linearity characteristic can be obtained. However, in the case of the invention disclosed in patent document 1, in order to obtain sufficient linearity, it is necessary to connect the electrode portions at the front end and the rear end with thin shaft portions and perform injection processing based on the resin covering them, and thus manufacturing becomes difficult.

In the case of the invention disclosed in patent document 2, the writing feeling can be changed by changing the material of the core rod made of the conductive material to a soft material. At this time, the strength of the core body is reduced, and therefore, the core rod of the conductive material is encased and reinforced with the resin. In order to ensure linearity, the mandrel bar tapers as it goes to the rear end side of the mandrel bar. Therefore, it is necessary to cover the rear end side of the mandrel bar formed of the conductive material with a protective member or the like so that sufficient strength can be maintained. The core of the electronic pen is a portion that is in direct contact with the operation surface, and is thin and short as viewed from the whole electronic pen, but it is required to have a desired strength, and it is also desirable that the manufacturing be easy.

In view of the above, an object of the present invention is to provide a core for an electronic pen, which has excellent detection characteristics of indication position and tilt, maintains sufficient strength, has a simple structure, and is easy to manufacture, and an electronic pen using the core.

Means for solving the problems

In order to solve the above problems, an electronic pen is provided with:

a cylindrical case having an opening at one end in the axial direction;

a core body mounted in the housing such that a front end portion in an axial direction protrudes from the opening of the housing; a kind of electronic device with high-pressure air-conditioning system

A signal generating circuit for generating a signal sent from the core,

the core body is composed of a core rod which has conductivity and receives the signal from the signal generating circuit and a protection component covering the core rod,

the core rod comprises a pen tip part at the front end side, an assembling part at the rear end side and a shaft part connecting the pen tip part and the assembling part,

the core rod is provided with an intermediate portion which is provided around the side surface of the shaft portion of the core rod so as to separate the shaft portion from the protection member and has a dielectric constant different from that of the protection member.

According to the electronic pen, the electronic pen includes a housing, a core, and a signal generating circuit, the core is mounted in the housing such that a tip portion in an axial direction protrudes from an opening of the housing, and the signal generating circuit generates a signal transmitted from the core. The core body is configured by providing an intermediate portion around the shaft portion of the mandrel and providing a protection member around the intermediate portion. Since the dielectric constants of the intermediate portion and the protective member are different, the capacitor is doubly provided around the shaft portion of the mandrel, and a signal (electric field) emitted from the shaft portion of the mandrel is suppressed, thereby realizing an electronic pen having excellent characteristics of indication position and linearity.

Drawings

Fig. 1 is a diagram for explaining a configuration example of an electronic pen according to an embodiment.

Fig. 2 is a diagram for explaining essential parts of the electronic pen according to the embodiment.

Fig. 3 is a diagram for explaining a structural example of a core of the electronic pen according to the embodiment.

Fig. 4 is a diagram for explaining another configuration example of a core rod of the core body of the electronic pen according to the embodiment.

Fig. 5 is a diagram for explaining another configuration example of a protective member of a core of an electronic pen according to the embodiment.

Fig. 6 is a diagram for explaining another configuration example of the electronic pen according to the embodiment.

Fig. 7 is a diagram for explaining another configuration example of the core of the electronic pen according to the embodiment.

Fig. 8 is a diagram for explaining another configuration example of the core of the electronic pen according to the embodiment.

Detailed Description

Embodiments of an electronic pen and a core for an electronic pen according to the present invention will be described below with reference to the drawings. The electronic pen according to the embodiment described below is an active capacitance type electronic pen that transmits a signal from the electronic pen side and detects a pointed position from a position on a position detection sensor that receives the signal.

[ structural example of active capacitance type electronic pen ]

Fig. 1 is a diagram for explaining a configuration example of the electronic pen 1 of the embodiment, and for the sake of explanation, a part of a case (housing) 2 of the electronic pen 1 is cut off, and the inside thereof is shown. Fig. 2 is a diagram for explaining the essential parts of the electronic pen 1. Specifically, fig. 2 (a) is an enlarged cross-sectional view of a main portion of the pen tip side of the electronic pen 1, which is not shown in fig. 1. Fig. 2 (B) is a schematic diagram of the electronic pen 1 in which a portion that realizes the functions of pen pressure detection and signal transmission is extracted.

As shown in fig. 1, the electronic pen 1 includes a cylindrical case (housing) 2 elongated in the axial direction (direction along the axial center), one of which is a pen point side and has an opening, and the other of which is closed. The case 2 is made of a conductive material (aluminum after anodic oxidation in this example), and includes a cylindrical case body 21 having a hollow portion therein, and a front cap 22 and a rear cap 23 coupled to the case body 21. The front cap 22 and the rear cap 23 are fitted to the housing main body 21 to form the housing 2.

As shown in fig. 2 (a), the front cap 22 has a cylindrical structure having a through hole 22a in the axial direction, and the external shape of the portion of the electronic pen 1 on the pen tip side is tapered so that the outer diameter becomes smaller as the portion is closer to the pen tip. The pen-tip-side end of the front cap 22 is an opening H of the through hole 22 a. In the hollow portion of the case 2, as shown in fig. 1, a board holder 3 and a battery 5 for holding a mounting member such as a printed board 8 are housed, and as shown in fig. 2 (a), a core holder (core holding portion) 6 and a pressure-sensitive member (pen pressure detecting portion) 7 are housed.

As shown in fig. 1 and 2 (a), the core 4 is inserted into the through hole 22a through the opening H of the front cap 22, and is attached to the core holder 6 inside the housing 2. The core 4 is detachable from the core holder 6. That is, the core 4 is detachable from the inside of the housing 2. As will be described in detail later, the core body 4 is composed of a core rod 41 made of a conductive material and a protective member 42 made of a nonconductive material, and has a structure in which a space (air layer) 43 is provided between the core rod 41 and the protective member 42.

The substrate holder 3 is formed of an insulating resin, for example, a liquid crystal polymer, and has the following structure: when housed in the hollow portion of the case 2, as shown in fig. 2 (a), the pressure-sensitive member holding portion 3a and the printed board mounting table portion 3b are continuous in the axial direction of the electronic pen 1. The pressure-sensitive member holding portion 3a has a cylindrical configuration including a hollow portion for accommodating the pressure-sensitive member 7 (a plurality of members for detecting pen pressure), and has an outer diameter smaller than an inner diameter of the through hole 22a of the front cap 22. The printed board mounting table portion 3b is a boat-like structure for mounting and holding the printed board 8, and specifically, is a structure in which a cylindrical body is cut substantially halfway in the axial direction.

The substrate holder 3 is fixed so that the entire pressure-sensitive member holding portion 3a and the printed substrate mounting table portion 3b are housed in the case 2 so that the pressure-sensitive member holding portion 3a is on the mandrel 41 side. As shown in fig. 2a, the core holder 6 for holding the core 4 is coupled to the pressure-sensitive member holding portion 3a of the substrate holder 3, and the pressure (pen pressure) applied to the core 4, mainly the core rod 41, is transmitted to the pressure-sensitive member 7 in the pressure-sensitive member holding portion 3 a.

As shown in fig. 1, a terminal conductor 51 is provided at an end of the board mount 3b of the board holder 3 opposite to the pressure-sensitive member holding portion 3 a. The terminal conductor 51 is electrically abutted against the positive side terminal 5a of the battery 5, and is electrically connected to the copper foil pattern of the power supply line of the printed board 8. A coil spring terminal 52 made of a conductive metal electrically connected to the negative terminal 5b of the battery 5 is provided at the fitting portion of the rear cap 23 with the housing main body 21. As shown in fig. 1, the battery 5 is inserted into the case 2 so as to connect the positive terminal 5a and the terminal conductor 51. After that, the rear cap 23 is fitted to the case main body 21 so as to press the negative side terminal 5b of the battery 5 with the coil spring terminal 52.

In this embodiment, the case main body 21 made of a conductive material is electrically connected to the ground conductor of the printed circuit board 8. Since the rear cap 23 and the case main body 21 are made of a conductive material, the negative terminal 5b of the battery 5 is electrically connected to the ground conductor of the printed board 8 via the rear cap 23 and the case main body 21. On the other hand, the positive side terminal 5a of the battery 5 is connected to the copper foil pattern of the power supply line of the printed board 8 via the terminal conductor 51. Thus, the voltage of the battery 5 is supplied as a power supply voltage of the circuit formed on the printed board 8.

The printed board 8 is provided with a circuit portion including the signal generating circuit 8S, IC (Integrate Circuit) 10 and its peripheral circuit components. The signal generating circuit 8S generates a signal transmitted from the core rod 41 of the electronic pen 1. The IC10 constitutes a control circuit that controls the transmission of the signal from the signal generating circuit 8S to the mandrel bar 41. The peripheral circuit section includes push switches (side switches) 11 and 12, which are operated via operation sections 11a and 12 a. Further, a conductor terminal member 14 connecting the stem 41 and the signal generating circuit 8S and a conductor terminal member 15 transmitting the detection output of the pen pressure from the pressure-sensitive component 7 are connected to the printed board 8.

As shown in fig. 2 (a), the core 4 is fitted to the core holder 6 made of a conductive material via the conductive elastic member 9, and is held by being coupled to the core holder 6. The core holder 6 is fitted to the holding member 73 of the pressure-sensitive member 7 in the pressure-sensitive member holding portion 3a of the substrate holder 3, and the pressure (pen pressure) applied to the core 4 is transmitted to the pressure-sensitive member 7.

In this case, the core holder 6 is configured such that the coil spring 13, which is an example of an elastic member made of a conductive material such as a conductive metal, provided between the core holder 6 and the substrate holder 3 is always biased toward the core rod 41 with respect to the substrate holder 3. The coil spring 13 and the conductor terminal member 14 together form an electrical connection member for transmitting a signal from the signal generating circuit 8S, which is controlled and transmitted by the IC10 disposed on the printed board 8, to the stem 41. Accordingly, a metal plate 13a is provided at the pen-point-side end of the pressure-sensitive element holding portion 3a of the substrate holder 3, and the coil spring 13 and the conductor terminal member 14 are electrically connected.

That is, as shown in fig. 2 (B), the signal from the signal generating circuit 8S is sent from the core rod 41 through the conductor terminal member 14, the metal plate 13a, the coil spring 13, the core holder 6, and the core rod 41 in this order. These conductor terminal member 14, coil spring 13, metal plate 13a, core holder 6, and core rod 41 constitute an electrical connection member, and form a transmission path of a position instruction signal from signal generation circuit 8S of printed board 8.

The pressure-sensitive member (pen pressure detecting portion) 7 of this embodiment is a case of using a capacitance variable capacitor whose capacitance varies according to the pen pressure applied to the mandrel bar 41. As shown in fig. 2 (a), the pressure-sensitive element 7 includes a plurality of elements including a dielectric 71, a terminal member 72, a holding member 73, a conductive member 74, and an elastic member 75. The terminal member 72 is made of a conductive material, and forms a first electrode of the capacity variable capacitor formed by the pressure-sensitive member 7. The conductive member 74 is made of, for example, conductive rubber, and the elastic member 75 is made of a coil spring made of a conductive material. The conductive member 74 and the elastic member 75 are electrically connected to constitute a second electrode of the capacity variable capacitor.

Thus, the capacitance of the capacitance variable capacitor formed between the terminal member 72 constituting the first electrode and the conductive member 74 constituting the second electrode changes according to the pressure applied to the mandrel 41. The capacitance change of the capacitance variable capacitor is supplied from the voltage sensing member 7 to the IC10 provided on the printed board 8 via the conductor terminal member 15, and the pen voltage is detected by the IC 10.

That is, in the electronic pen 1 of this embodiment, as shown in fig. 2 (a), the core 4 is mounted to the core holder 6 inside the housing 2 so as to be movable in the axial direction. Thus, the core 4 has the following structure: the plunger 41 and the core holder 6 are pushed into the housing 2 by the pen pressure applied to the plunger 41 by the user, and the pen pressure can be detected by pressing the pressure-sensitive member 7. In addition, the following structure is adopted: when the pen pressure applied to the core rod 41 is released, the core holder 6 and the core 4 can be restored to the initial state shown in fig. 2 (a) by the action of the coil spring 13.

The IC10 of the electronic pen 1 controls the position detection sensor to transmit a burst signal (position instruction signal) for coordinate detection (position detection) corresponding to the signal from the signal generation circuit 8S. Thereby, the indication position of the electronic pen 1 on the position detection sensor can be detected on the position detection sensor side. In a circuit including the IC10, which is formed on the printed board 8 of the electronic pen 1, the operation of detecting the pen pressure based on the capacitance at the pressure-sensitive member 7 is performed during the burst signal is transmitted. After the end of the burst signal transmission period, the IC10 transmits an encoded signal obtained by modulating the signal from the signal generating circuit 8S according to the detected pen pressure from the plunger 41, and notifies the pen pressure to the position detection sensor side. Thereby, the detection of the pen pressure applied to the core 4 of the electronic pen 1 can also be achieved on the position detection sensor side.

In this way, the electronic pen 1 of this embodiment realizes a function in which the position detection sensor indicates a position on the position detection sensor and detects a pen pressure applied to the core rod 41 and notifies the position detection sensor. Further, the electronic pen 1 of this embodiment has a feature in the structure of the core 4 that the linearity characteristic concerning the position detection is well maintained, so that the indication position can be appropriately detected on the position detection sensor side. The core body 4 used in the electronic pen 1 of this embodiment has sufficient strength as a core body, and has a simple structure and can be easily manufactured.

[ structural example of core 4 ]

Fig. 3 is a diagram for explaining a structural example of the core 4 of the electronic pen 1. In fig. 3, (a) of fig. 3 is an external view of the protection member 42 of the core body 4, and (B) of fig. 3 is an external view of the core rod 41 of the core body 4. As shown in fig. 2 (a), the core body 4 of this embodiment is composed of 2 members, that is, a core rod 41 (fig. 3 (B)) and a protection member 42 (fig. 3 (a)), as shown in fig. 3.

The plug 41 is a rod-like body having conductivity, and has a columnar structure having a portion with different thickness except for a tip portion. The core rod 41 is formed of, for example, a metal material. In this embodiment, the core rod 41 is formed using stainless steel (SUS (Steel Special Use Stainless)) or brass. As shown in fig. 3 (B), the mandrel 41 is composed of 3 parts, i.e., a tip portion 41a, a shaft portion 41B, and an attachment portion 41 c. The pen tip 41a is a portion formed in an egg-shaped shape (oblong spherical shape) at the distal end portion of the mandrel bar 41, and is configured to efficiently radiate a position indication signal toward the position detection sensor.

The shaft portion 41B is a portion connecting the pen tip portion 41a and the fitting portion 41c, and includes 3 portions, i.e., a front shaft portion 41B1, an intermediate shaft portion 41B2, and a rear shaft portion 41B3, as shown in fig. 3 (B). The rear shaft portion 41b3 forms a fitting portion with a protection member 42 described in detail later. Therefore, the rear shaft portion 41b3 is hereinafter referred to as a fitting portion 41b3. In this embodiment, as shown in fig. 3B, the diameter of the portion of the tip 41a having the widest width (hereinafter referred to as the wide portion) is L1, and the diameter of the fitting portion 41B3 of the shaft portion 41B is L2. The diameter L1 of the wide portion of the pen tip 41a is shorter than the diameter L2 of the fitting portion 41b3 (L1 < L2).

In this embodiment, the side surface of the fitting portion 41B3 is knurled at a portion indicated by a symbol RT in fig. 3 (B). The knurling process is a process of finely forming irregularities on a metal, and is also called embossing (knudling). Since the knurling has an anti-slip effect, as will be described later, when the core rod 41 is attached to the protection member 42, the core rod 41 can be prevented from easily coming off from the protection member 42.

The diameter of the front shaft portion 41b1 gradually increases from the pen tip side toward the rear end side. Similarly, the diameter of the intermediate shaft portion 41b2 gradually increases from the pen tip side toward the rear end side. In addition, the diameter change is large at the connecting portion between the front shaft portion 41b1 and the intermediate shaft portion 41b 2. All portions of the front shaft portion 41b1 have a diameter shorter than the diameter L1 of the pen tip portion 41 a. In addition, the diameter of all portions of the intermediate shaft portion 41b2 is smaller than the diameter L2 of the fitting portion 41b 3. Therefore, if the diameter of the front shaft portion 41b1 is Lb1 and the diameter of the intermediate shaft portion 41b2 is Lb2, the shaft portion 41b has a structure in which the diameter gradually increases from the front end side toward the rear end side as in Lb1< Lb2< L2.

As described with reference to fig. 2 (a) and (B), the fitting portion 41c is a portion to be fitted to the core holder 6 provided inside the electronic pen 1 via the conductive elastic member 9. That is, the core 4 can be attached to the electronic pen 1 by pushing the attachment portion 41c of the core rod 41 into the cup portion of the core holder 6 to which the conductive elastic member 9 is attached, and the core 4 can be detached from the electronic pen 1 by pulling out. That is, the core body 4 including the core rod 41 and the protection member 42 described later is detachable from the electronic pen 1 via the fitting portion 41c of the core body 4.

As shown in fig. 2 (a) and (B), the protection member 42, which is another constituent member of the core body 4, covers the side surfaces of the pen tip portion 41a and the shaft portion 41B of the core rod 41, protects the core rod 41, and realizes a good writing feeling. In this embodiment, the protective member 42 is formed of various resin materials, and can be formed using, for example, polyamide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyacetal, or the like. In this embodiment, the protective member 42 is formed using polyacetal (polyacetal). Polyacetal is also known as POM (polyoxymethylene).

The protection member 42 includes a tapered front end portion 42a tapered toward the front end and an extension portion 42b extending from the rear end surface of the front end portion 42a toward the rear end side. An insertion hole 42c is provided inside the protection member 42, in which the rear end surface of the extension portion 42b is opened in the longitudinal direction, and the plug 41 is inserted and assembled. The center in the longitudinal direction of the insertion hole 42c coincides with the center (axial center) in the longitudinal direction of the protection member 42. As shown in fig. 3 (a) and (B), the length LY of the insertion hole 42c of the protection member 42 in the longitudinal direction (the entire length) coincides with the length LY from the front end of the pen tip portion 41a of the plug 41 to the position slightly ahead of the rear end surface of the fitting portion 41B3 of the plug 41.

The inner diameter of the insertion hole 42c at the position corresponding to the wide portion of the pen tip 41a of the plug 41 is the same as L1 or slightly shorter than L1, and the inner diameter of the insertion hole 42c at the position corresponding to the fitting portion 41b3 of the plug 41 is the same as L2 or slightly shorter than L2. The insertion hole 42c is a hole portion having no irregularities on the inner wall surface thereof and a tapered shape from the opening on the rear end side toward the front end, and the plug 41 is easily inserted.

Accordingly, when the plug 41 is inserted into the insertion hole 42c of the protection member 42 from the pen tip 41a, as shown in fig. 2 (a) and (B), the portion of the tip 41a of the plug 41 closer to the distal end side than the wide portion is brought into close contact with the inner wall surface of the insertion hole 42 c. As shown in fig. 2 (a) and (B), the side surface of the fitting portion 41B3 of the plug 41 is in close contact with the inner wall surface around the opening of the insertion hole 42 c. Thereby, the protection member 42 is firmly attached to the core rod 41. In this way, when the plug 41 is inserted into the insertion hole 42c of the protection member 42 and attached, as shown in fig. 2 (a) and (B), a space (air layer) 43 is formed between the shaft portion 41B of the plug 41 and the inner wall surface of the insertion hole 42 c.

That is, as described above, as shown in fig. 3 (a), the insertion hole 42c of the protection member 42 tapers from the portion of the diameter L2 on the rear end side to the portion of the diameter L1 on the front end side. As described above with reference to fig. 3 (B), since the diameter of the fitting portion 41B3 is L2 and the diameter of the wide portion of the pen tip portion 41a is L1, the mandrel 41 has a tapered shape from the fitting portion 41B3 toward the pen tip portion 41 a. The diameter of many portions of the front shaft portion 41b1 is smaller than the diameter L1 of the wide portion of the pen tip portion 41a, and the diameter of all portions of the intermediate shaft portion 41b2 is smaller than the diameter L2 of the fitting portion 41b 3.

Thus, assume that: the core rod 41 is inserted into the insertion hole 42c of the protection member 42 and pushed in, and is mounted at a fixed position. In this case, as shown in fig. 2 (a) and (B), a space (air layer) 43 is formed as an intermediate portion between the side surfaces of the front shaft portion 41B1 and the intermediate shaft portion 41B2 of the mandrel 41 and the inner wall surface of the insertion hole 42c of the protection member 42. That is, a space (air layer) 43 is provided around the front shaft portion 41b1 and the intermediate shaft portion 41b2, and a protection member 42 is provided outside the space 43. The space (air layer) 43 and the protective member 42 made of polyacetal can be considered as dielectrics, which are substances having dielectric properties superior to electric conductivity, and the respective dielectric constants are different.

That is, in the core body 4 of this embodiment, as shown in fig. 2 a, a space (air layer) 43 is provided around the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel bar 41, and a protection member 42 is provided outside the space. Therefore, the space (air layer) 43 and the protection member 42 are doubly enclosed around the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel 41. In other words, it can be said that a capacitor having a space (air layer) 43 as a dielectric and a capacitor having polyacetal (protective member 42) as a dielectric are provided around the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel 41. In this case, since the dielectric constants of the air layer and polyacetal are different, 2 capacitors using dielectrics having different dielectric constants are provided.

In contrast, as shown in fig. 2 (a) and (B), the inner wall surface of the protection member 42 and the side surface of the tip portion of the plug 41 are in close contact with each other at the tip end side of the tip portion 41a of the plug 41, so that no space is generated, and only the tip end portion 42a of the protection member 42 is present. In other words, it can be said that the portion of the tip 41a of the mandrel 41 closer to the tip than the wide portion is provided with 1 capacitor structure using polyacetal (the protective member 42) as a dielectric.

As a result, the signal (electric field) emitted from the tip portion 41a of the plug 41 on the tip side of the wide portion is emitted relatively efficiently only through the protection member 42. Therefore, a signal (electric field) emitted through the tip portion 41a of the plug 41 on the tip side of the wide portion becomes large. However, the signals (electric fields) emitted from the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel 41 are suppressed by the double capacitor of the space 43 and the protection member 42. Therefore, the signal (electric field) emitted through the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel bar 41 becomes smaller. Further, since the diameter of the front shaft portion 41b1 of the plug 41 is smaller than the diameter of the wide portion of the pen tip portion 41a, the signal (electric field) emitted from the pen tip portion 41a can be made smaller than the signal (electric field) emitted from the pen tip portion 41 a.

That is, the signal (electric field) emitted from the tip portion 41a of the plug 41 toward the tip end side from the wide portion can be increased, and the signal (electric field) emitted from the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the plug 41 can be reduced. In this way, the signal (electric field) leaking from the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel bar 41 can be suppressed. This improves the linearity of the detection characteristic as the indication position when the electronic pen 1 is tilted, and prevents the indication position of the electronic pen 1 from being shifted on the position detection device side.

In addition, conventionally, the core is formed by injection molding (injection molding) as follows: the core rod 41 is inserted into a mold and fixed at a fixed position, and polyacetal is injected into the mold to form a core body. However, since the core body 4 according to this embodiment is formed by the press-fitting method in which the core rod 41 and the protection member 42 are separately formed and the core rod 41 is inserted into the insertion hole 42c of the protection member 42, the manufacturing of the core body 4 itself can be easily performed. The core rod 41 and the protection member 42 may be formed by a suitable method, respectively.

As described with reference to fig. 2 and 3, the core 4 of this embodiment has a structure in which the protective member 42 covers the pen tip portion 41a and the shaft portion 41b of the core rod 41. Thus, the thickness of the extension 42b of the protection member 42 covering the shaft portion 41b can be increased, and therefore the diameter of the portion of the core 4 protruding from the opening H of the front cap 22 can be increased. Thus, as shown in fig. 1 and fig. 2 (a), the strength of the extension 42b of the core body 4 and the shaft portion 41b of the mandrel bar 41 can be enhanced. In addition, as shown in fig. 2 (a), the interval between the side surface of the extension portion 42b of the protection member 42 and the inner wall surface of the front cap 22 becomes extremely small. Therefore, the loosening of the core 4 during writing can be substantially prevented, and the core 4 can be protected even if a force is applied to the tip end 42a of the core 4 in a direction intersecting the axial direction.

In addition, in order to be able to appropriately detect the pen pressure, the core 4 is able to slide in the axial direction. However, the rear end surface 42T of the front end portion 42a of the protection member 42 and the front end surface 22T of the front cap 22 are opposed to each other with a slight gap. Thus, even if a large pen pressure is suddenly applied or the electronic pen 1 is dropped from the desk onto the floor and a large force is applied to the front end portion 42a in the axial direction of the electronic pen 1, the rear end face 42T of the front end portion 42a and the front end face 22T of the front cap 22 are butted. Thus, the core 4 is not pushed into the housing 2 of the electronic pen 1 unnecessarily, and a problem such as breakage of the pressure-sensitive member 7 can be prevented.

Effect of the embodiment

The core 4 of the above embodiment is provided with a space (air layer) 43 as an intermediate portion around the shaft portion 41b of the mandrel 41, and an extension portion 42b of the protection member 42 is provided around the space 43. Since the space 43 and the protective member 42 have different dielectric constants, the capacitor is doubly provided around the shaft portion 41b of the mandrel 41, and a signal (electric field) emitted from the shaft portion 41b of the mandrel 41 can be suppressed. Thus, by suppressing an excessive electric field from the shaft, a core for an electronic pen having excellent characteristics of a pointing position and linearity when tilting the electronic pen can be realized. In addition, since the core 4 itself has a simple structure, a core for an electronic pen that is easy to manufacture can be realized. Therefore, by using the core 4 according to the above embodiment, an electronic pen having excellent detection characteristics of the indication position and the tilt can be realized.

Modification example

< other examples of core rod 41 >

Fig. 4 is a diagram for explaining another configuration example of the mandrel bar 41 of the core body 4. As shown in the core rod 41A of fig. 4 (a), the shaft portion 41bA connecting the pen tip portion 41aA and the fitting portion 41cA may include a front shaft portion b1A and a fitting portion b3A. That is, the shaft portion 41bA is not divided into the front shaft portion 41b1 and the intermediate shaft portion 41b2 as in the shaft portion 41b shown in fig. 2 and 3, but has a single-stage straight structure. As described above, the shaft portion of the mandrel bar may have a 1-stage structure other than the fitting portion 41cA as shown in fig. 4 (a), or may have a 2-stage structure other than the fitting portion 41c or a multi-stage structure of two or more stages as shown in fig. 2 and 3.

As shown in the core rod 41B of fig. 4 (B), the core rod includes a pen tip 41aB, a shaft 41bB, and an attachment portion 41cB, and the shaft 41bB includes a front shaft B1B and a fitting portion B3B. The shaft portion 41bB and the fitting portion 41cB are substantially the same as the mandrel 41A of fig. 4 (a), but the nib portion 41aA has a spherical shape. That is, the shape of the pen tip 41a of the plug 41 is not limited to an egg shape, and may be a ball shape, a shell shape having a dome shape at the tip, an arrow shape having a sharpened tip, or the like in consideration of the state of radiation of a signal (electric field).

As shown in fig. 4 (C), the pen tip 41aC, the shaft 41bC, and the fitting portion 41cC may be integrally formed of a metal material, but the fitting portion 44 may be formed as another member. In this case, the fitting portion 44 may be formed of a metal material or may be formed of another material such as hard rubber into a cylindrical shape having a thickness. This is because the nib 41aC, the shaft portion 41bC, and the fitting portion 41cC of the plug 41C are integrally formed of a metal material and have conductivity, so that even if the fitting portion 44 is formed of a nonconductive material, the conductivity of the plug 41C is not lost.

The mandrels 41A, 41B, 41C described with reference to fig. 4 are examples, and various modifications can be made. In other words, the plug can have various shapes that have conductivity from the front end to the rear end thereof, and that can be provided with an intermediate portion such as a space (air layer) 43 between the axial center portion and the protection member 42 when inserted into the insertion hole 42c of the protection member 42 and assembled at a fixed position.

< other examples of the protective Member 42 >

Fig. 5 is a diagram for explaining another configuration example of the protection member 42 of the core 4. As described with reference to fig. 3, the protective member 42 is formed using a resin material, and in this embodiment, is described as being formed of polyacetal. However, it is not limited thereto. The protective member can also be formed using a technique called two-color molding (two-molding) in which 1 molded article is made of 2 resin materials.

The protection member 42A (fig. 5 (a)), the protection member 42B (fig. 5 (B)), and the protection member 42C (fig. 5 (C)) shown in fig. 5 are formed to have the same shape as the protection member 42 of the core 4 shown in fig. 1 to 3. That is, the protection members 42A, 42B, and 42C shown in fig. 5 include the distal end portions 42aA, 42aB, and 42aC, the extension portions 42bA, 42bB, and 42bC, and the insertion holes 42cA, 42cB, and 42cC, as in the protection member 42 described above. However, both of them are formed by a two-color molding technique using 2 resins of polyacetal and elastomer.

In the protective member 42A shown in fig. 5 (a), most of the distal end portion 42aA and the extension portion 42bA are formed of polyacetal, and a dome-shaped contact portion 42x formed of an elastic body is provided at the foremost end portion (portion in contact with the operation surface) of the distal end portion 42 aA. The elastomer means a soft polymer material having elasticity such as rubber, and the softness, elasticity and other physical properties can be adjusted by blending the material. By providing the contact portion 42x of the elastic body at the tip portion 42aA in this manner, a desired writing feeling can be achieved.

The writing feeling means a state at the time of writing when the electronic pen is brought into contact with the operation surface to perform writing, a writing state, that is, a feeling transmitted to the hand of the user by the electronic pen. Therefore, by providing the contact portion 42x formed of the elastic body, the electronic pen is more flexibly contacted with the operation surface at the time of writing, and a feeling of writing can be obtained.

In the case of the protective member 42A shown in fig. 5 (a), a double capacitor is formed by the tip side of the tip portion 42aA of polyacetal and the contact portion 42x of the elastic body. Since the thickness of the contact portion 42x is small, there is a possibility that a signal (electric field) emitted from the contact portion 42x side is suppressed. Therefore, as in the case of the protective member 42B shown in fig. 5 (B), the contact portion 42y of the distal end portion 42aB is made thicker. Accordingly, only the contact portion 42y made of an elastic body is formed on the pen tip side, and it is possible to prevent the signal (electric field) emitted from the contact portion 42y side from being suppressed, and also to realize a desired writing feeling.

Further, as shown in the protective member 42C of fig. 5 (C), a portion of the front end portion 42aC of the protective member 42C located on the front end side of at least the wide portion of the pen tip portion 41a of the plug 41 is made to be an elastic body contact portion 42z. In this way, the signal (electric field) emitted from the pen tip 41a of the core rod 41 can be efficiently emitted without being significantly suppressed, and a desired writing feeling can be achieved.

The protection members 42A, 42B, and 42C described with reference to fig. 5 are examples, and various modifications are possible. In other words, the protection member may be configured such that the signal (electric field) from the tip portion of the core rod can be emitted without attenuation, and the signal (electric field) from the shaft portion of the core rod can be emitted with attenuation through the intermediate portion such as the space (air layer) and the protection member.

The contact portions 42x, 42y, 42z attached to the tip may have conductivity by two-color molding. By having conductivity, a strong electric field can be emitted from the core.

< other structural example of electronic Pen 1 >

Fig. 6 is a diagram for explaining another configuration example of the electronic pen 1. In fig. 6, the same reference numerals are given to the same components as those of the electronic pen 1 shown in fig. 2, and detailed description thereof will be omitted because it is repeated. In the case of the electronic pen 1 of the above embodiment, as shown in fig. 1 and 2, the entire front end 42a of the protection member 42 of the core 4 protrudes from the opening H of the front cap 22 of the housing 2. However, it is not limited thereto.

The core 4X of the electronic pen 1A shown in fig. 6 is configured using, for example, a core rod 41A and a protection member 42X shown in fig. 4 (a), and a space (air layer) 43X is provided around the shaft portion 41b1A of the core rod 41A. However, as shown in fig. 6, the protection member 42X is provided with a side surface portion 42Xa1 of which the rear end side of the front end portion 42Xa becomes parallel to the axial center. Of course, the inside of the core 4X may be configured in the same manner as the core 4 of the above embodiment.

In addition, in the case of the electronic pen 1A shown in fig. 6, the opening HA of the front cap 22A is larger than the opening H of the front cap 22 of the electronic pen 1 shown in fig. 2. The opening HA of the front cap 22A is similar in shape to the rear end surface 42XT of the protection member 42X on the front end side thereof, but the diameter of the front end side of the opening HA is slightly longer than the rear end surface 42XT of the front end portion 42Xa of the protection member 42. Thus, the core 4X is configured such that the side surface portion 42Xa1 on the rear end side of the front end portion 42Xa of the protection member 42X enters the opening HA of the front cap 22A.

However, in the case of the front cap 22A of the electronic pen 1A shown in fig. 6, an annular protruding portion 22P protruding inward is provided at a position where the front cap 22A is retracted slightly from the front end toward the rear end side. The front end surface 22Px of the extension 22P faces the rear end surface 42XT of the front end 42Xa of the core 4X. In a state where the electronic pen 1A shown in fig. 6 is not in use, a small gap is left between the front end surface 22Px of the protruding portion 22P and the rear end surface 42XT of the core 4X. Thus, in the case of the electronic pen 1A, the constitution is also: when the pen pressure is applied to the core 4X, the core 4X is pushed in toward the rear end side, and when the pen pressure is released, the core 4X is pushed out to the original position.

Therefore, in the case of the electronic pen 1A shown in fig. 6, even if a large pen pressure is suddenly applied or the electronic pen 1A falls down and a large force in the axial direction is applied to the tip portion of the core body 4X, the rear end face 42XT of the tip portion 42Xa and the tip face 22Px of the front cap 22A abut against each other. Thus, the core 4X is not unnecessarily pushed into the housing (case) of the electronic pen 1A, and a defect such as breakage of the pressure-sensitive member 7 can be prevented.

In the case of the electronic pen 1A shown in fig. 6, the side surface portion 42Xa1 on the rear end side of the front end portion 42Xa of the protection member 42X faces the inner wall surface on the front end side of the opening HA of the front cap 22A. This can prevent the loosening of the core 4X during writing from occurring substantially, and can protect the core 4 even if a force is applied to the tip 42Xa of the core 4X in a direction intersecting the axial direction. Further, by making the distance between the side surface of the extension portion 42Xb of the core 4X and the inner wall surface of the extension portion 22P of the front cap 22A as narrow as possible, it is possible to add stronger strength to the force of the core 4X with respect to the direction intersecting the axial direction. In this case, the protruding portion 22P of the front cap 22A may be extended further in the axial direction to have a larger facing area with the side surface of the extending portion 42Xb of the core 4X.

< other structural example of core 4 >

Fig. 7 and 8 are diagrams for explaining another configuration example (core 4Y) of the core 4 of the electronic pen 1. The core 4 described above is composed of 2 members, namely, the protection member 42 and the core rod 41, using fig. 3. In contrast, the core body 4Y of this example is composed of 3 members, that is, the tip member 45, the extension member 46, and the plug 41. In fig. 7, (a) of fig. 7 is an external view of the tip member 45, (B) of fig. 7 is an external view of the extension member 46, and (C) of fig. 7 is an external view of the plug 41.

As is clear from a comparison between fig. 3 (B) and fig. 7 (C), the core rod 41 of the core 4Y of this example is identical to the core rod 41 of the core 4 described above. Accordingly, the same reference numerals as those of the mandrel bar 41 shown in fig. 3 (C) are given to the mandrel bar 41, and the description of the mandrel bar 41 is omitted because it is repeated. In this example, the core rod 41 is also formed of stainless steel (SUS (Steel Special Use Stainless)) or brass, and the core rod 41 is formed of a metal material.

In the core 4Y of this example, the tip member 45 and the extension member 46 constitute portions corresponding to the protection member 42 of the core 4 described above using fig. 3. As shown in fig. 7 (a), the tip member 45 has a conical appearance with a circular arc at the tip portion, and is a so-called dome-shaped member having a large circular bottom surface opening 45H provided in the bottom surface and a space formed inside. The space on the distal end side of the space provided inside the distal end member 45 is a pen tip fitting portion 451 into which the pen tip portion 41a of the core rod 41 is fitted. The bottom surface side space of the space provided inside the front end member 45 is an extension member fitting portion 452 into which a front side portion (a front side tapered portion 461, a side surface groove portion 46G, and a front side portion of the intermediate portion 462) of the extension member 46 described later is fitted.

An inner protrusion 452P is provided annularly along the inner edge of the bottom surface opening 45H at a portion of the inner wall surface of the extension member fitting portion 452 on the bottom surface opening 45H side. The portion of the front end member 45 outside the bottom surface opening 45H is a front end member rear end surface 45T having a thickness in a direction intersecting the axial center (the central axis of the core 4Y) (in this example, in a direction orthogonal thereto). The front-end-member rear end surface 45T is a portion facing the front end surface 22T of the front cap 22 of the housing 2 in the case where the core 4Y of this example is mounted on the electronic pen 1, as in the case where the core 4 shown in fig. 2 is used. In this embodiment, the front end member 45 is formed of Silicon rubber (Silicon rubber).

As shown in fig. 7B, the extension member 46 is a tubular (tubular) member having a through hole formed in the axial direction (the same direction as the axial center), and has a front side (the front end member 45 side) which is a front side opening 46FH and a rear side which is a rear side opening 46BH. The extension member 46 includes 3 parts, that is, a front tapered part 461 having a tapered shape (a tapered shape), an intermediate part 462, and a rear part 463 having a slightly shorter diameter than the intermediate part 462, from the front side. A side groove 46G is provided at a boundary portion between the front tapered portion 461 and the intermediate portion 462 of the side surface (outer wall surface) of the extension member 46.

The extension member 46 can be formed of the same material as the protection member 42 of the core 4 described above. Specifically, the extension member 46 can be formed of various resin materials such as polyamide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyacetal, and the like. In this embodiment, the extension member 46 is formed using polyacetal (polyacetal). As mentioned above, polyacetal is also known as POM (polyoxymethylene).

As is clear from an examination of fig. 7 (a) and 7 (B), the inner space of the distal end member 45, that is, the extension member fitting portion 452, is identical in shape to the front portion of the extension member 46 (the portion constituted by the front tapered portion 461, the side surface groove portion 46G, and a part of the front side of the intermediate portion 462). Therefore, by inserting and pushing the front tapered portion of the extension member 46 from the bottom surface opening portion 45H of the front end member 45, the front end member 45 and the extension member 46 can be joined. In this case, the inner front end surface 452T of the extension member fitting portion 452 abuts against the front end surface 461T of the extension member 46, and the inner protrusion 452P of the extension member fitting portion 452 of the front end member 45 is fitted into the side surface groove portion 46G of the extension member 46. Accordingly, the inner wall surface of the extension member fitting portion 452 of the distal end member 45 and the side surface (outer wall surface) of the front portion of the extension member 46 are in close contact with each other, and do not easily come off.

In this way, the outer shape and the inner shape of the joint member formed by joining the distal end member 45 and the extension member 46 are the same as those of the protection member 42 shown in fig. 3 (a). As described above, the tip member 45 is made of silicone rubber, has elasticity (resiliency), and the extension member 46 is a hard member made of POM. Thus, by pulling the two apart with a certain degree of force, the joined front end member 45 and the extension member 46 can also be separated. Thus, the distal end member 45 and the extension member 46 are configured to be detachable.

As can be seen from fig. 7 (a) and (B), the joint member formed by joining the distal end member 45 and the extension member 46 has an insertion hole 47h in the longitudinal direction on the inner side into which the plug 41 is inserted and assembled. The through hole 47h corresponds to the through hole 42c in the protection member 42 described above using fig. 3 (a). The center in the longitudinal direction of the insertion hole 47h coincides with the center (axial center) in the longitudinal direction of the joint member constituted by the tip member 45 and the extension member 46. The length (full length) of the insertion hole 47h in the longitudinal direction of the engagement member corresponds to a length LY from the tip end of the pen tip 41a of the plug 41 to a position slightly forward of the rear end surface of the fitting portion 41b3 of the plug 41 shown in fig. 7 (C).

The inner diameter of the insertion hole 47h of the joint member at a position corresponding to the wide portion of the pen tip 41a of the plug 41 is the same as L1 or slightly shorter than L1, and the inner diameter of the insertion hole 47h at a position corresponding to the fitting portion 41b3 of the plug 41 is the same as L2 or slightly shorter than L2. The insertion hole 47h is a hole portion having no irregularities on the inner wall surface thereof and a tapered shape from the opening on the rear end side toward the front end, and the plug 41 is easily inserted.

When the plug 41 is inserted into the insertion hole 47h of the joint member including the tip member 45 and the extension member 46 from the pen tip portion 41a, as shown in fig. 8, a portion of the tip portion 41a of the plug 41 closer to the tip end side than the wide portion is brought into close contact with the inner wall surface of the insertion hole 47 h. As shown in fig. 8, the side surface of the fitting portion 41b3 on the rear end side of the plug 41 is in close contact with the inner wall surface around the opening of the insertion hole 47 c. Thus, the joining member formed by joining the distal end member 45 and the extension member 46 is attached to the mandrel bar 41, thereby forming the mandrel bar 4Y. In the case of the core body 4Y thus configured, as shown in fig. 8, a space (air layer) 43Y is also formed between the shaft portion 41b of the mandrel bar 41 and the inner wall surface of the insertion hole 47h of the joining member.

In this way, in the case of the core 4Y of this example, it can be considered that the space (air layer) 43Y and the joint member composed of the tip member 45 made of silicone rubber and the extension member 46 made of polyacetal are dielectrics which are substances superior in dielectric properties to the conductivity. The dielectric constants of the space 43Y and the bonding member (mainly the extension member 46) are also different. Therefore, in the case of the core body 4Y of this example, the signals (electric fields) emitted from the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel bar 41 are also suppressed by the double capacitor of the space 43 and the joint member composed of the front end member 45 and the extension member 46.

Therefore, in the case of the core body 4Y of this example, the signal (electric field) emitted through the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel bar 41 also becomes small. Further, since the diameter of the front shaft portion 41b1 of the plug 41 is smaller than the diameter of the wide portion of the pen tip portion 41a, the signal (electric field) emitted from the pen tip portion 41a can be made smaller than the signal (electric field) emitted from the pen tip portion 41 a.

In this way, in the case of the core body 4Y of this example, the signal (electric field) emitted through the portion of the tip portion 41a of the plug 41 on the tip side of the wide portion can be increased, and the signal (electric field) emitted from the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the plug 41 can be reduced. In other words, the signal (electric field) leaking from the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel bar 41 can be suppressed. Thus, even when the core 4Y of this example is used for the electronic pen 1, the linearity of the detection characteristic as the indication position when the electronic pen 1 is tilted can be improved, and the occurrence of the offset of the indication position of the electronic pen 1 on the position detection device side can be prevented.

In this way, even in the case of the core 4Y of this example, the same effects as those in the case of the core 4 described above can be obtained. The core body 4 of this example is formed by the mandrel bar 41, the tip member 45, and the extension member 46. In this case, the distal end member 45 and the extension member 46 are joined to constitute a joining member. The joining member corresponds to the protection member 42 of the core 4 described using fig. 3. The core body 4Y can be formed by a press-fit method in which the core rod 41 is inserted into the insertion hole 47h of the joining member. Therefore, the manufacturing of the core 4Y itself can be easily performed. The core rod 41, the tip member 45, and the extension member 46 may be formed by a suitable method.

In particular, in the case of the core 4Y of this example, since the tip member 45 is formed using an elastic member such as silicone rubber, a softer writing feeling can be achieved. Further, by forming the front end member 45 by an elastic member such as silicone rubber, a gap (interval) between the rear end surface 45T of the front end member 45 and the front end surface 22T of the front cap 22 of the housing 2 of the electronic pen 1 can be narrowed. This is because, if the front end member 45 is formed of an elastic member, the core 4Y can be pushed to a certain extent toward the rear end side even after the rear end surface 45T of the front end member 45 contacts the front end surface 22T of the front cap 22.

In addition, since the electronic pen is used with the pen tip in contact with the operation surface, the pen tip is worn by friction. In the core body 4Y including the tip member 45, the extension member 46, and the plug 41, only the tip member 45 can be easily replaced. Therefore, in the case of the core 4Y, only the tip member 45 needs to be replaced, and therefore, the cost is reduced as compared with the case of replacing the entire core. That is, the core 4Y for the electronic pen that can be used more economically can be realized.

< intermediate portion of substitution space (air layer) 43 >

In the above-described embodiment, as shown in fig. 2, a space (air layer) 43 as an intermediate portion is provided between the shaft portion 41b (the front shaft portion 41b1 and the intermediate shaft portion 41b 2) of the plug 41 and the extension portion 42b of the protection member 42. Similarly, in the core body 4X of the electronic pen shown in fig. 6, a space (air layer) 43X as an intermediate portion is provided between the shaft portion 41b1A of the core rod 41A and the extension portion 42Xb of the protection member 42X. In the case of the core body 4Y shown in fig. 7 and 8, a space (air layer) 43Y is formed as an intermediate portion between the shaft portion 41b of the plug 41 and the inner wall surface of the insertion hole 47h of the joint member constituted by the distal end member 45 and the extension member 46. However, the intermediate portion is not limited to a space (air layer).

For example, materials having dielectric constants different from those of the protective member 42 are applied to the side surfaces of the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the mandrel 41 by various methods such as coating, vapor deposition, fusion, and winding so as to have the same thickness as the space 43 at the same position. In this way, the intermediate portion of a different material from the protective member 42 can be provided on the side surfaces of the front shaft portion 41b1 and the intermediate shaft portion 41b2 of the plug 41. The mandrel bar 41 having the intermediate portion provided in this manner is inserted into the insertion hole 42c of the protection member 42. Thus, the extension portion 42b of the protection member 42 can be positioned outside the intermediate portion, and the same structure as that in which a double capacitor is formed around the front shaft portion 41b1 and the intermediate shaft portion 41b2 can be achieved.

Similarly, the core body 4X may be configured by providing an intermediate portion in the shaft portion 41bA of the plug 41A shown in fig. 6 with a material having a dielectric constant different from that of the protection member 42X, and inserting the intermediate portion into the insertion hole of the protection member 42X. In the case of the core 4Y shown in fig. 7 and 8, the space (air layer) 43Y may be partially filled with a material having a dielectric constant different from that of the tip member 45 and the extension member 46, and the like, to provide an intermediate portion.

In this way, the intermediate portion provided in the cores 4, 4X, 4Y is not limited to the space (air layer) 43, and the intermediate portion is made of a material having a dielectric constant different from that of the protective members 42, 42X, so that the core for the electronic pen having excellent detection characteristics of the indication position and tilt can be formed.

< others >

In the above embodiment, the fitting portion 41b3 is provided in the plug 41, but this is not a limitation. The fit portion 41b3 may not be provided in the mandrel bar 41, and the intermediate shaft portion 41b2 may extend to the fit portion 41b 3. In this case, instead of the fitting portion 41b3 of the plug 41, an inwardly protruding portion is provided at the corresponding portions of the protection member 42 and the extension member 46, that is, at the opening portion at the rear end side of the protection member 42 and the extension member 46. In this way, the protruding portions of the protection member 42 and the extension member 46 are fitted to the rear end portion of the intermediate shaft portion 41b2 of the plug 41, and the plug 41 can be fixed to the protection member 42 and the extension member 46. At this time, the rear end portion of the intermediate shaft portion 41b2 of the plug 41 facing the protruding portions of the protection member 42 and the extension member 46 may be knurled.

Description of the reference numerals

1. 1A electronic pen, 2 housing, 21 housing main body, 22A front cap, 22A through hole, opening, 22T front end face, 22P protruding part, 22Px front end face, 23 rear cap, 3 substrate holder, 3a pressure-sensitive member holding part, 3B printed substrate mounting table part, 4X, 4Y core body, 41A, 41B, 41C, 41X core rod, 41A, 41aA, 41aB, 41aC pen tip part, 41B, 41bA, 41bB, 41bC, 41B1A shaft portion, 41B1, B1B front side shaft portion, 41B2 intermediate shaft portion, 41B3, B3B fitting portion (rear side shaft portion), 41C, 41cA, 41cB, 41cC fitting portion, 42A, 42B, 42C, 42X protecting member, 42A, 42aA, 42aB, 42aC, 42Xa front end portion, 42B, 42bA, 42bB, 42bC, 42Xb extending portion, 42C, 42cA, 42cB, 42cC inserting hole, 42X, 42Y, 42z contact portions, 42T, 42XT rear end face, 42Xa1 side face portion, 43X, 43Y intermediate portion (space, air layer), 44 fitting portion, 45 front end member, 451 nib fitting portion, 452 extension member fitting portion, 452P inside protrusion, 45T front end member rear end face, 45H bottom face opening portion, 46 extension member, 46G side face groove portion, 461 front side taper portion, 462 intermediate portion, 463 rear side portion, 46FH front side opening portion, 46BH rear side opening portion, 5 battery, 5a positive side terminal, 5B negative side terminal, 6 core holder, 7 voltage sensing component, 71 dielectric, 72 terminal member, 73 holding member, 74 conductive member, 75 elastic member, 8 printed circuit board, 8S signal generating circuit, 9 conductive elastic member, 10 IC,11, 12 push switch, 11A, 12A operation portion, 13 coil spring, 13a … metal plate, 14 … conductor terminal member, 15 … conductor terminal member, 51 … terminal conductor, 52 … coil spring terminal.

Claims

1. An electronic pen, comprising:

a cylindrical case having an opening at one end in the axial direction;

A signal generating circuit for generating a signal sent from the core,

2. The electronic pen of claim 1, wherein the pen comprises a pen body,

the protection member has an insertion hole into which the core rod is inserted,

a fitting portion extending in a direction intersecting the axial center is provided on the rear end side of the shaft portion of the mandrel,

when the plug is inserted into and fitted to the insertion hole, the pen tip portion of the plug is brought into close contact with a front end portion of the insertion hole, and the fitting portion of the plug is brought into close contact with a rear end portion of the insertion hole.

3. The electronic pen of claim 1, wherein the pen comprises a pen body,

a fitting portion protruding in a direction intersecting the axial center and knurling a side surface is provided on a rear end side of the shaft portion of the mandrel,

4. The electronic pen of claim 1, wherein the pen comprises a pen body,

the protection member includes an insertion hole into which the mandrel bar is inserted, an inner diameter of a portion of the insertion hole corresponding to the shaft portion of the mandrel bar is longer than an outer diameter of the shaft portion,

when the core rod is inserted into and fitted to the insertion hole, a space is provided between the protection member and the shaft portion as the intermediate portion.

5. The electronic pen of claim 1, wherein the pen comprises a pen body,

in the case where the core rod is inserted and fitted into the insertion hole,

the nib of the core rod is closely attached to the front end portion of the insertion hole,

the jogged part of the mandrel is clung to the rear end part of the insertion hole,

a space is provided as the intermediate portion between the protection member and the shaft portion.

6. The electronic pen of claim 1, wherein the pen comprises a pen body,

a core holding part for installing the core is arranged in the shell,

the fitting portion of the core rod of the core is fitted with respect to the core holding portion, and is electrically connected to the signal generating circuit.

7. The electronic pen of claim 1, wherein the pen comprises a pen body,

the front end portion of the protection member of the core is tapered.

8. The electronic pen of claim 1, wherein the pen comprises a pen body,

the core rod of the core body is formed of a metallic material,

the protective member of the core is formed of a resin material.

9. The electronic pen of claim 1, wherein the pen comprises a pen body,

the core rod of the core body is formed of stainless steel or brass.

10. The electronic pen of claim 1, wherein the pen comprises a pen body,

the protective member of the core is formed of a resin material and is formed by two-color molding using different materials for the tip portion and the other portions.

11. The electronic pen of claim 1, wherein the pen comprises a pen body,

the protective member of the core is formed by two-color molding using an elastomer at the tip end portion and polyacetal at the other portion.

12. The electronic pen of claim 10, wherein the pen is further configured to,

the tip portion formed by two-color molding is a material having conductivity.

13. The electronic pen of claim 1, wherein the pen comprises a pen body,

the protective member of the core is composed of a dome-shaped front end member and a cylindrical extension member,

the front end member has a conical appearance with a circular arc at the front end, a large circular bottom opening is arranged on the bottom surface, and the inner side is formed into a space,

the extension member has a through hole formed in an axial direction.

14. A core for an electronic pen is mounted in a cylindrical housing of the electronic pen having an opening at one end in an axial direction so that a tip in the axial direction protrudes from the opening of the housing, the core being characterized in that,

Comprises a core rod having conductivity and receiving a signal from the signal generating circuit and a protective member covering the core rod,

15. The electronic pen cartridge according to claim 14, wherein,

16. The electronic pen cartridge according to claim 14, wherein,

a fitting part which extends in a direction crossing the axis and is knurled on the side surface is arranged on the rear end side of the shaft part,

17. The electronic pen cartridge according to claim 14, wherein,

18. The electronic pen cartridge according to claim 14, wherein,

a fitting part extending in a direction crossing the axis is provided at the rear end side of the shaft part,

in the case where the core rod is inserted and fitted into the insertion hole,

19. The electronic pen cartridge according to claim 14, wherein,

the protection member is composed of a dome-shaped front end member and a cylindrical extension member,

the extension member has a through hole formed in an axial direction.