Electronic pen

Abstract

To provide an electronic pen having both a writing function to a paper medium or the like and a function as a position indicator to an electronic device and having impact resistance.SOLUTION: A ferrite core 3 is fixed to a housing 1 in a portion of the pen tip side inside the housing 1. A core 2 is configured into a bar-like body by resin containing graphite. The core 2 is inserted into the ferrite core 3 through an opening 1h of the housing 1, and includes an extraction unit 2b functioning when extracted from the housing 1. A diameter of a main body part 2c of the core 2 is made longer than the thickness in a diameter direction of the ferrite core 3.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic pen that functions as a position indicator for electronic devices equipped with a position detection device, such as a tablet PC (Personal Computer). [Background technology]

[0002] In recent years, electronic pens and tablet PCs have also come to be used in the field of education. For example, electronic pens and tablet PCs are lent to each child or student, and they can be taught the stroke order of kanji characters through character input, or used to obtain answers to questions. Inputting data into a tablet PC using an electronic pen is convenient because data can be re-entered many times without using paper media. Electronic pens are relatively durable, for example, because they use a core made of POM resin.

[0003] FIG. 3 is a diagram showing a conventional example of an electronic pen. For example, electronic pens 100 and 200 shown in FIG. 3(A) and (B) are both electromagnetic induction type. A component in which coils 104 and 204 are wound around the outer surface of ferrite cores 103 and 203 is mounted inside housings 101 and 201. A capacitor (not shown) is connected to coils 104 and 204 to form a resonance circuit. Cores 102 and 202 are inserted through the through holes of ferrite cores 103 and 203 from the openings of housings 101 and 201, and come into contact with writing pressure detection units 105 and 205, making it possible to detect the writing pressure applied to cores 102 and 202.

[0004] Unlike writing on paper, drawing input to a tablet PC using an electronic pen allows easy rewriting over and over again, but on the other hand, it is easy to switch the display screen, and the display screen can be switched in an instant, and the input information can be erased. Therefore, in order to hold the input information, an operation must be performed to save the input information in a built-in storage medium. There is a demand for using not only an electronic pen and a tablet PC, but also paper media such as notebooks in combination for learning. For this reason, it is required to be able to record on paper media without changing the electronic pen, and to be able to input drawings to a tablet PC as well.

[0005] Patent Document 1, which will be described later, discloses an electronic pen incorporating a mechanical pencil unit, and by using the invention disclosed in Patent Document 1, it is possible to realize an electronic pen that combines the functions of writing on paper media and inputting data into a tablet PC. By using this electronic pen, it is possible to record and store necessary information on paper media, and to input answers to questions into a tablet PC for immediate answering. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2007-219723 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the case of an electronic pen incorporating the mechanical pencil unit disclosed in Patent Document 1, the lead of the mechanical pencil is usually thin, about 0.5 mm, and the pen tip of the electronic pen itself is also thin. For this reason, when a child in the lower grades of elementary school tries to use it, it is difficult to control the amount of force applied, and the lead of the mechanical pencil easily breaks, which may result in the child being unable to write on paper as intended or damaging the operation screen of the tablet PC.

[0008] When considering use in the field of education, especially for use by elementary school children in the lower grades, it is desirable to realize an electronic pen that can be used in the same way as a conventional electronic pen configured as shown in Figure 3, and that can also record on paper media. It is also expected that electronic pens will be frequently dropped or hit. For this reason, they must be resistant to external shocks and not easily broken.

[0009] In view of the above, the present invention provides an electronic pen that has both a function for writing on paper media and a function as a position indicator for electronic devices, and also has resistance to impact. [Means for solving the problem]

[0010] In order to solve the above problems, A cylindrical housing having an opening at an end on the pen tip side; A cylindrical member fixed to the housing at a pen tip side portion inside the housing; a core body formed into a rod-shaped body using a material obtained by mixing at least a pigment and a resin, the core body being inserted into the cylindrical member through the opening of the housing and attached thereto; Equipped with When the core body is attached to the housing, a side surface of the core body faces an inner wall surface of the tubular member and an inner wall surface of the opening of the housing with a small gap therebetween; The diameter of the portion of the core body that is inserted into the cylindrical member is smaller than the difference between the outer diameter and the inner diameter of the cylindrical member. Large, The core body has a pull-out portion which is a recess that functions when the core body is pulled out of the housing, and when the core body is attached to the housing, the pull-out portion protrudes from the opening. The present invention provides an electronic pen. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram for explaining an embodiment of an electronic pen according to the present invention; [Diagram 2] FIG. 11 is a diagram for explaining another example of the electronic pen of the present invention. [Diagram 3] FIG. 1 is a diagram showing an example of the configuration of a conventional electronic pen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the electronic pen of the present invention will be described with reference to the drawings. Note that there are two types of electronic pens (position indicators) and position detection devices: an electromagnetic induction type (EMR (Electro Magnetic Resonance technology) type) and an active electrostatic coupling type (AES (Active Electrostatic) type).

[0015] In the electromagnetic induction method, the position detection device is provided with a sensor unit in which multiple loop coils are arranged in each of the X-axis and Y-axis directions. A transmission period in which power is supplied sequentially to the multiple loop coils of the sensor unit to generate a magnetic field is alternated with a reception period in which the supply of power is stopped and a magnetic field is received from the outside. The corresponding electronic pen is provided with a resonant circuit consisting of a coil and a capacitor, and generates a signal by causing a current to flow through the coil in response to the magnetic field from the sensor unit, and transmits this signal including writing pressure information to the position detection sensor. The position detection device receives this during the reception period and detects the position indicated by the electronic pen and the writing pressure.

[0016] In the case of the active electrostatic coupling method, the electronic pen transmits a signal including writing pressure information from an oscillator circuit mounted on the electronic pen, and this is received by a position detection device to detect the indicated position and writing pressure.

[0017] The electronic pen of the present invention can be used for both electromagnetic induction type and active electrostatic coupling type. However, in the following embodiment, for the sake of simplicity, the present invention will be described as being applied to an electromagnetic induction type (EMR type) electronic pen.

[0018] [Example of electronic pen configuration] Fig. 1 is a diagram for explaining an embodiment of an electronic pen of the present invention. Fig. 1(A) is a cross-sectional view of the pen tip side portion of an electronic pen of this embodiment, which is divided into two in the axial direction and the front portion is removed. However, in Fig. 1(A), the core body 2 is not shown in cross section, but in its entirety. Fig. 1(B) is an enlarged view of the core body 2, and Fig. 1(C) is a cross-sectional view showing the pen tip side portion of Fig. 1(A) at a further enlargement.

[0019] As shown in FIG. 1(A), the housing 1 of the electronic pen of this embodiment is cylindrical. As shown in FIG. 1(A) and (C), the pen tip side of the housing 1 is tapered, and its tip portion is an opening 1h. A core body 2, which will be described later, is inserted and removed through this opening 1h. A ferrite core 3 formed in a cylindrical shape is stored in the pen tip side portion inside the housing 1. The end portion of the ferrite core 3 on the pen tip side (front end side) is fixed to the housing 1. In addition, a cylindrical buffer member 5 made of, for example, elastomer is provided on the opposite side (rear end side) of the ferrite core 3 from the pen tip side, and the end portion on the rear end side of the ferrite core 3 is fixed to the housing 1 via this buffer member 5.

[0020] In this way, the ferrite core 3 is fixed to the housing 1 at both its front and rear end portions. Although the cushioning member 5 is provided only on the rear end side of the ferrite core 3 in FIG. 1(A), a cushioning member may also be provided on the front end side of the ferrite core 3. In short, it is sufficient that the ferrite core 3 is fixed to the housing 1 directly or via an intermediate member such as a cushioning member so as not to move or rattle within the housing 1. The cushioning member 5 can be made of various elastic materials such as rubber, sponge, felt, etc.

[0021] 1(A) and (C), a coil 4 is wound around the outer surface of the ferrite core 3. A pen pressure detection unit 7 configured as a variable capacitance capacitor (described later) and a capacitor (not shown) mounted on a circuit board 9 are connected in parallel to the coil 4 to form a resonant circuit. A pressing member 6 that connects the core body 2 and the pen pressure detection unit 7 is provided on the rear end side of the buffer member 5. The end portion of the pressing member 6 on the pen tip side is a recess into which the rear end side of the core body 2 fits, and the end portion on the opposite side to the pen tip side is a protrusion for pressing the pen pressure detection unit 7.

[0022] The core 2 is formed into a cylindrical shape (rod-like body) from a material containing a pigment. A pigment refers to a powder used for coloring that is insoluble in water or oil. Inorganic pigments include graphite (black), titanium (white), chrome vermilion (vermilion), yellow lead (yellow), and iron oxide (red), while organic pigments include permanent red (red), phthalocyanine green (green), and fast yellow (yellow). There are various other pigments. By mixing the pigment with a medium such as resin, clay, or wax, cores of various colors can be constructed. Therefore, depending on the pigment used, a core 2 can be constructed that can leave handwriting of the desired color on a paper medium or the like.

[0023] In this embodiment, graphite (black lead, graphite) is used as a pigment, and the core body 2 is formed by mixing it with a predetermined resin. The core body 2 can leave black handwriting on paper media, etc., similar to that of a pencil, and is less likely to wear out. The core body 2 also has the same hardness as a core body formed of POM resin of a conventional electronic pen. Therefore, even if an electronic pen equipped with the core body 2 is used on the operation surface of a tablet PC, it does not cause inconvenience such as scratching the operation surface. By using such a core body 2, an electronic pen having two functions, a writing function on paper media, etc. and a function as a position indicator for a tablet PC, etc., can be realized. In this embodiment, the ratio of graphite and resin constituting the core body 2 is 50:50. The resin is polyethylene.

[0024] As shown in FIG. 1(B), the core 2 is made up of four parts: a pen tip part 2a, a pull-out part 2b, a main body part 2c, and a holding part 2d. The pen tip part 2a is a tapered part, and its tip is rounded. The pull-out part 2b is a recess (groove) provided between the pen tip part 2a and the main body part 2c. When removing the core 2 attached to the housing 1, the user can easily remove the core 2 from the housing 1 by hooking the pull-out part 2b with the nail of a finger or the like and pulling it out. The main body part 2c is a part located between the pull-out part 2b and the holding part 2d. The holding part 2d is a part located on the rear end side of the main body part 2c, and has a diameter smaller than that of the main body part 2c.

[0025] As shown in FIG. 1(A), the core body 2 is inserted into the ferrite core 3 through the opening 1h of the housing 1, and the holding portion 2d of the core body 2 is fitted into the recess of the pressing member 6, and is attached inside the housing 1. In this case, the tip portion including the pull-out portion 2b of the core body 2 protrudes from the opening 1h of the housing 1. The pen pressure detection unit 7 is composed of a holding member 71 that holds the convex portion of the pressing member, a first electrode 72, a spacer 73 formed in a ring shape, a dielectric body 74 that is a circular plate-like body, and a second electrode 75. The second electrode 75 is provided in contact with one surface of the dielectric body. The first electrode 72 is arranged to be separated from the other surface of the dielectric body 74 via the spacer 73 when no pressing force (load) is applied thereto. The holding member 71 is made of an elastic material such as synthetic rubber, and the spacer 73 is made of a hard resin or the like.

[0026] The core body 2 attached in the housing 1 is movable in the axial direction. When a writing pressure is applied to the pen tip portion 2a of the core body 2, the core body 2 is pushed into the housing 1 in response to the writing pressure, and the pressing member 6 moves the first electrode 72 closer to the dielectric 74 side through the holding member 71 in response to this, and the first electrode is brought into contact with the dielectric 74. Therefore, the distance and contact area between the first electrode 72 and the dielectric 74 change in response to the pressing force applied to the pen tip portion 2a, and the capacitance between the first electrode and the second electrode changes in response to this. The writing pressure applied to the pen tip portion 2a of the core body 2 can be detected in response to the change in the capacitance between the first electrode 72 and the second electrode 75. When the writing pressure applied to the pen tip portion 2a of the core body 2 is released, the core body 2 is pushed back by the first electrode 72 and the holding member 71 and returns to its original position.

[0027] A board holding member 8 is provided behind the second electrode of the pen pressure detection unit 7, and a circuit board 9 is fitted and held in a recess of the board holding member. Various circuit components such as a control IC (Integrated Circuit) and a capacitor are mounted on the circuit board 9. Both ends of the coil 4 and electric wires from the first electrode and second electrode of the pen pressure detection unit 7 are connected to the circuit board 9. This allows the circuit section mounted on the circuit board 9 to detect the pen pressure and transmit a signal containing information indicating the pen pressure as a change in the phase of a signal (magnetic field) generated in the coil 4 by resonance.

[0028] Furthermore, the above-mentioned buffer member 5 and board holding member 8 are held by a cylindrical holding member 10 provided inside the housing 1. As a result, the ferrite core 3 and coil 4, buffer member 5, pressing member 6, pen pressure detection unit 7, and board holding member 8 are held within the housing 1. Although not shown, the rear end side of the circuit board 9 is fixed to the rear end of the housing 1. As a result, the circuit board 9 is also held within the housing 1. In this manner, the electronic pen of this embodiment is configured.

[0029] In the electronic pen of this embodiment, the diameter of the housing 1 is 9.0 mm as shown in FIG. 1(A). Also, as shown in FIG. 2(C), the inner diameter of the ferrite core 3 is 3.0 mm, and the outer diameter is 5.0 mm. Also, the diameter of the opening 1h of the housing 1 is 2.95 mm. Also, the diameter of the main body 2c of the core body 2 is 2.85. In the case of a conventional electronic pen, as shown in FIG. 3, the core body is made of a high-strength material such as POM resin, and in order to maintain the strength of the ferrite core, the total thickness of both ends in the diametric direction of the ferrite core is made larger than the diameter of the core body.

[0030] 3(A), in the case of conventional electronic pen 100, the diameter of opening 101h of housing 101 is larger than the diameter of through-hole 103h of ferrite core 103 (the inner diameter of ferrite core 103). Similarly, in the case of conventional electronic pen 200, as shown in FIG. 3(B), the diameter of opening 201h of housing 201 is larger than the diameter of through-hole 203h of ferrite core 203 (the inner diameter of ferrite core 203).

[0031] This is to avoid interfering with the axial movement of the core bodies 102, 202. In this case, since the ferrite cores 103, 203 are thick, even if the core bodies 102, 202 come into contact with the ferrite cores 103, 203, neither of them will be damaged, and there is a high degree of freedom in design. For this reason, the diameters of the openings 101h, 201h of the housings 101, 201 can be designed to be large.

[0032] However, in the case of the electronic pen of this embodiment, the total thickness of both ends in the diameter direction of the ferrite core 3 is 2.0 mm, and the diameter of the main body 2c of the core 2 is 2.85 mm. That is, in the case of the electronic pen of this embodiment, the diameter of the core 2 is made thicker than in the past, and the thickness of the ferrite core 3 is made thinner than in the past. Therefore, in the case of the electronic pen of this embodiment, the diameter of the main body 2c of the core 2 is made longer than the length obtained by subtracting the inner diameter from the outer diameter of the ferrite core 3.

[0033] In this way, by increasing the diameter of the main body 2c of the core 2, the strength of the core 2 can be increased. Conversely, the thickness of the ferrite core 3 is considerably thinner than that of the conventional electronic pen. However, the ferrite core 3 is fixed to the housing 1. Therefore, the ferrite core 3 does not move or rattle within the housing 1. Also, as shown in Figs. 1(A) and 1(C), the diameter of the opening 1h of the housing 1 is smaller than the inner diameter of the ferrite core 3. Therefore, even when the electronic pen of this embodiment is used for writing, the position of the core 2 is restricted by the inner wall portion of the opening 1h of the housing 1, and the core 2 does not come into contact with the ferrite core 3.

[0034] Also, suppose that the electronic pen of this embodiment is dropped, and a large load (force) is applied to the pen tip portion 2a of the core body 2 protruding from the housing 1 in a direction intersecting the axial direction. Even in this case, the position of the core body 2 is restricted by the inner wall portion of the opening 1h of the housing 1, and the core body 2 does not come into contact with the ferrite core 3. Therefore, in the case of the electronic pen of this embodiment, the ferrite core 3 will not come into contact with the core body 2 and be damaged, and the ferrite core 3 will not move or rattle within the housing 1, so the ferrite core 3 will not be damaged by external impact.

[0035] [Another example of core 2] Fig. 2 is a diagram for explaining another example of the core body of the electronic pen of the present invention. The core body 2A of the electronic pen of this example is formed into a cylindrical shape from a resin containing graphite, similar to the core body 2 shown in Fig. 1, but its outer shape is different from that of the core body 2 shown in Fig. 1. That is, as shown in Fig. 2(A), the core body 2A of this example is composed of four parts, a pen tip part 2Aa, a pull-out part 2Ab, a main body part 2Ac, and a holding part 2Ad.

[0036] The pen tip portion 2Aa is a tapered portion, and its tip is rounded. The pull-out portion 2Ab is a portion where the pen tip portion 2Aa's main body portion 2Ac side is a convex portion that protrudes outward. The main body portion 2Ac is a portion located between the pull-out portion 2Ab and the hold portion 2Ad. The hold portion 2Ad is a portion located on the rear end side of the main body portion 2Ac, and has a diameter smaller than that of the main body portion 2Ac.

[0037] In this way, in the case of the core body 2A in which the pull-out portion 2Ab is configured as a convex portion, when this is attached to the housing 1, a gap is generated between the end of the housing 1 and the pull-out portion 2Ab of the core body 2A, as shown in Fig. 2(B). As a result, when removing the core body 2A attached inside the housing 1, the user can easily remove the core body 2A from the housing 1 by hooking the pull-out portion 2Ab with the nail of a finger or the like and pulling it out.

[0038] Incidentally, an electronic pen can be configured as shown in Fig. 2(B) simply by using the core body 2A shown in Fig. 2(A) instead of the core body 2 of the electronic pen described using Fig. 1. That is, if the sizes of the main body portion 2Ac and the holding portion 2Ad of the core body 2A are the same as those of the core body 2 shown in Fig. 1, an electronic pen can be configured using the core body 2A instead of the core body 2.

[0039] [Effects of the embodiment] By using a resin containing a pigment such as graphite for the cores 2, 2A, it is possible to leave a physical mark on paper media, as in the case of a conventional pencil. Furthermore, since the cores 2, 2A are made of a resin containing a pigment such as graphite, they are less likely to wear out and can also function as a core for an electronic pen. In other words, it is possible to realize a writing instrument (electronic pen) that has both a writing function on paper media, etc. and a function as a position indicator for electronic devices equipped with a position detection device such as a tablet PC.

[0040] In addition, since the diameter of the core body can be made larger than that of the conventional core body, an electronic pen using a core body that is resistant to impact can be realized. Conversely, if a core body with a larger diameter is used, the thickness of the ferrite core 3 becomes thinner, and the ferrite core 3 becomes weak against impact. However, by making the diameter of the opening 1h on the pen tip side of the housing 1 shorter than the inner diameter of the ferrite core 3, it is possible to prevent the core bodies 2, 2A from directly contacting the ferrite core 3. In addition, by fixing the ferrite core 3 to the housing 1 at least at the end on the front end side, preferably at both the end on the front end side and the end on the rear end side, it is possible to prevent the ferrite core 3 from rattling inside the housing 1. With these configurations, an electronic pen with a thin ferrite core 3 that is not damaged can be realized.

[0041] [Variations] The diameter of the main body 2c of the core 2 and the inner diameter and outer diameter of the ferrite core 3 described with reference to Fig. 1 are merely examples, and various sizes can be used depending on the size of the housing 1. In this case, the diameter of the main body of the core 2 needs to be larger (longer) than the value (length) obtained by subtracting the inner diameter from the outer diameter of the ferrite core 3. In other words, the diameter of the main body 2c of the core 2 is configured to be longer than the sum of the thicknesses of both ends in the diametrical direction of the ferrite core 3. This makes it possible to configure a core 2 that is thicker than that of a conventional electronic pen.

[0042] In the above-mentioned embodiment, the core 2, 2A is described as being made of a resin containing graphite. In this case, by adjusting the graphite content, an electronic pen with different writing densities when writing on a paper medium can be constructed. That is, there are pencils with different densities, such as 2B, B, HB, F, H, and 2H, and it is also possible to realize an electronic pen with different writing densities.

[0043] In addition, by changing the type of resin containing graphite, it is possible to adjust the thickness of the writing and change the writing feel. In the above-mentioned embodiment, polyethylene is used as the resin, but other examples include polypropylene, polystyrene, polyamide, etc. Of course, the core body can also be formed by mixing graphite and a specific clay and baking it. In the case of such a core body, the core body itself wears down and becomes shorter when writing on a paper medium, etc., so the core body needs to be replaced more frequently, so it is preferable to use a material that can reduce wear of the resin, etc.

[0044] Furthermore, by changing the pigment used, a core body capable of leaving marks in various colors can be constructed, and this can be used as the core body of an electronic pen.

[0045] In the above-described embodiment, the present invention is applied to an electronic pen of an electromagnetic induction type, but the present invention is not limited to this. For example, the present invention can be applied to an electronic pen of an active electrostatic coupling type. In other words, the present invention can be applied to a case where an electronic pen of an active electrostatic coupling type is realized that has a function of writing on a paper medium and a function as a position indicator for an electronic device.

[0046] Specifically, an active electrostatic coupling type electronic pen may be equipped with a coil for charging. In this case, a ferrite core is arranged around the core body to prevent noise from entering the core body. In such a case, the present invention can be applied. In addition, in the case of an active electrostatic coupling type electronic pen that is battery-powered and replaceable, a cylindrical member may be used instead of a ferrite core to protect the core body or to allow stable movement of the core body in the axial direction. In such a case, the present invention can be applied.

[0047] If the core is made of a resin containing graphite and a conductive material is further added, a conductive core can be formed, and an active electrostatic coupling type electronic pen can be realized. In other words, in the case of an active electrostatic coupling type electronic pen, the core used must have conductivity. For this reason, a core with good conductivity can be formed by mixing a conductive material such as graphite with the core, or by providing a metallic shaft core in the core. [Explanation of symbols]

[0048] 1...housing, 1h...opening, 2, 2A...core body, 2a, 2Aa...pen tip portion, 2b, 2Ab...pulling portion, 2c, 2Ac...main body portion, 2d, 2Ad...holding portion, 3...ferrite core, 4...coil, 5...buffer member, 6...pressure member, 7...pen pressure detection portion, 71...holding member, 72...first electrode, 73...spacer, 74...dielectric, 75...second electrode, 8...board holding member, 9...circuit board, 10...cylindrical holding member

Claims

1. A cylindrical housing having an opening at an end on the pen tip side; A cylindrical member fixed to the housing at a pen tip side portion inside the housing; a core body formed into a rod-like body using a material obtained by mixing at least a pigment and a resin, the core body being inserted into the cylindrical member through the opening of the housing and attached thereto; Equipped with When the core body is attached to the housing, a side surface of the core body faces an inner wall surface of the tubular member and an inner wall surface of the opening of the housing with a small gap therebetween; a diameter of a portion of the core body that is inserted into the cylindrical member is greater than a difference between an outer diameter and an inner diameter of the cylindrical member; The core body has a pull-out portion which is a recess that functions when the core body is pulled out of the housing, and when the core body is attached to the housing, the pull-out portion protrudes from the opening.

1. An electronic pen comprising:

2. A cylindrical housing having an opening at an end on the pen tip side; A cylindrical member fixed to the housing at a pen tip side portion inside the housing; a core body formed into a rod-like body using a material obtained by mixing at least a pigment and a resin, the core body being inserted into the cylindrical member through the opening of the housing and attached thereto; Equipped with When the core body is attached to the housing, a side surface of the core body faces an inner wall surface of the tubular member and an inner wall surface of the opening of the housing with a small gap therebetween; a diameter of a portion of the core body that is inserted into the cylindrical member is greater than a difference between an outer diameter and an inner diameter of the cylindrical member; a pull-out portion which is a protrusion that functions when the device is pulled out from the housing, and the pull-out portion protrudes from the opening when the device is attached to the housing; 1. An electronic pen comprising:

3. 3. The electronic pen according to claim 1, A writing pressure detection unit for detecting a writing pressure applied to the core body; a pressing member for pressing the writing pressure detection unit; Equipped with The end of the core body opposite to the pen tip side becomes a holding part having a smaller diameter than the other parts, and the holding part is fixed by being fitted into the pressing member.

1. An electronic pen comprising:

4. 3. The electronic pen according to claim 1, The inner diameter of the cylindrical member is larger than the diameter of the opening of the housing.

1. An electronic pen comprising:

5. 3. The electronic pen according to claim 1, the cylindrical member is a ferrite core, A coil is wound around the outer side surface of the ferrite core, and a capacitor is connected to the coil to form a resonant circuit, which functions as an electromagnetic induction type electronic pen.

1. An electronic pen comprising:

6. 3. The electronic pen according to claim 1, The pigment is an inorganic pigment or an organic pigment.

1. An electronic pen comprising:

7. 3. The electronic pen according to claim 1, The portion of the core body on the pen tip side is tapered.

1. An electronic pen comprising:

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